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4. RESULTS &
DISCUSSIONS
218
The present study has been aimed at the ability of
some selected bacteria to degrade the organic matter of
the effluent of domestic wastewater and to demonstrate
the usage of various kinds of materials as filter media for
treatment of wastewater. The basic principle in a
biofilter is the biodegradation of pollutants by
microorganisms. Inoculation of bacteria is essential for
bioremediation of sewage.
4.1.1 Standardization of physico-chemical parameters
Sewage sample was collected and analyzed for 10
successive days. The values of various physico –
219
chemical parameters were tabulated in Table 4, page
418. The physico-chemical parameters of the raw
sewage are as follows: pH ranged from 7.1 – 8.05,
electric conductivity ranged from 2300 – 2900
mMhos/cm2, temperature ranged from 22 – 29
0C, total
suspended solids ranged from 345 – 410 mg/lit, volatile
suspended solids ranged from 113 – 170 mg/lit,
chlorides ranged from 125 – 201 mg/lit, total hardness
ranged from 355 – 455 mg/lit, alkalinity ranged from
400 – 560 mg/lit, COD ranged from 460 – 550 mg/lit,
BOD ranged from 110 – 220 mg/lit, total nitrogen
ranged from 39.4 – 56.1 mg/lit, total phosphorus ranged
from 5.92 – 12.0 mg/lit, oil and grease ranged from 28 –
50.4 mg/lit and sludge volume index ranged from 110 –
140 ml/g SS.
220
The results were found to be similar with the
results obtained by Abdul et al. (2010). They analyzed
wastewater samples from Al-Rustamiyah WWTP, and
reported that pH ranged from 6.87 – 8.40 with mean of
7.70, electric conductivity ranged from 1910.0 – 2120.0
µS/cm with mean of 1949.78, TSS ranged from 10.0 –
112.0 mg/lit with mean of 49.30, chlorides ranged from
171.44 – 254.92 mg/lit with mean of 205.25, BOD
ranged from 12.0 – 66.0 mg/lit with mean of 26.36 and
COD ranged from 36.0 – 80.0 mg/lit with mean of 53.10.
4.1.2 Bacterial adaptation studies
Adaptation studies were carried out by growing
the bacteria in nutrient media supplemented with 5 %, 10
%, 20 %, 30 %, 40 % 50 % 60 %, 75 %, 90 % and 100 %
221
sterilized sewage. The objective of adaptation of a
microbial community to sewage is to compare the
degradation potential in the field before and after a
specific pollutant spill has occurred (Eva and Springaely,
2003).
Bacterial survival in at various sewage concentrations
Upon adaptation to various sewage
concentrations plate count was performed on nutrient
agar plates. 1ml of sample was taken from 90% sterilized
sewage fed culture broth. The sample was serially
diluted up to 10-8
. 1ml of the sample was taken form 10-8
dilution and it was subjected to plating by pour plate
method for the development of microbial colonies in
222
nutrient agar medium and incubated in an incubator at
37°C for 24 hours.
For isolating the bacteria from adapted nutrient
culture broth (fed with 90% sterilized sewage) the
nutrient agar plates were inoculated with 1ml inoculum
from 10-8
dilution by pour plate method. The samples
were observed for growth after 24 hours of incubation.
Bacterial colonies (viable count) were observed in
nutrient agar plates and results are tabulated in table 5
page 419. Nitrobacter sps., showed more colony
forming units i.e. 45 X 108 when compared to other
microorganisms in the present study. It was followed by
Nitrosomonas sps., Pseudomonas denitrificans, Bacillus
mucilaginosus, Chromatium sps., Bacillus licheniformis,
Bacillus megatherium, Rhodococcus terrae,
223
Lactobacillus acidophilus. But Thiobacillus ferrooxidans
has not shown any colony on agar plate. Thiobacillus
ferrooxidans grows at pH 2.5 and it might be the reason
for absence of growth on nutrient agar plates of near to
neutral pH.
The purpose of adaptation is to allow bacterial
community to rapidly adapt to their new environment
(Eva and Springaely, 2003). There are several
mechanisms, or combinations by which microbial
communities can adapt to their environment. Firstly,
there can be an increase in population size of those
organisms that tolerate or even degrade the compound by
induction of appropriate genes. Secondly, the cells can
adapt through mutations of various kinds, such as single
nucleotide changes or DNA rearrangements that result in
224
resistance to or degradation of the compound. Thirdly,
they may acquire genetic information from either related
or phylogenetically distinct populations in the
community.
In the present study various microorganisms with
their respective characteristics were studied for their
degree of pollutant elimination (or) bioremediation of
sewage. Sewage collected was transferred to plastic tub
which was called as system and was inoculated with
respective adapted culture of bacteria. After 24 hours of
incubation (or) reaction time, samples were collected
from each system and various physicochemical
parameters were analyzed. The results were tabulated.
225
Efficiency of individual microorganism was
calculated using BOD removal efficiency formula. BOD
of raw sewage sample and treated sewage sample were
determined. The efficiency was calculated using the
following formula.
BOD removal efficiency =
Influent BOD – Effluent BOD X 100
Influent BOD
4.1.3 Evaluation of microorganisms based on
bioremediation of sewage sample
(Performance of individual microbial species)
4.1.3.1 Bacillus megatherium
The studies on bioremediation capabilities of
Bacillus megatherium revealed that there was a
reduction of BOD by 41.67% and Phosphorus decreased
226
by 60.85%. The changes in the remaining parameters are
tabulated in table 6 page 420. The percentage of
reduction of BOD in the wastewater by Bacillus
megatherium reached more than 40%. The reduction of
phosphorus levels upto 60%, which implies that it will
be useful for bioremediation of sewage. Hence, it was
considered to be one of the microorganism of sewage
treatment consortium.
Role of Bacillus megatherium in bioremediation of
sewage
Bacillus megatherium is a gram positive,
endospore forming, rod shaped, aerobic bacterium. The
strain was collected from National Collection of
Industrial Microorganisms (NCIM-2104) and was used
in the present study. Min Jin et al. (2005) reported 90%
of COD removal efficiency using microorganism
227
Bacillus megatherium as candidate in the consortium for
bioremediation of sewage. Usharani et al. (2009),
observed the phosphate removal efficiency of 38-55% by
bacillus sps., from wastewater. Usharani et al. (2009),
further reported that there is a 92.5% of phosphate
removal by using a consortium which include Bacillus
sps., Pseudomonas sps., and Enterobacter sps., It was,
therefore, envisaged that Bacillus megatherium is
suitable candidate for the removal of phosphorus from
domestic wastewater.
Phosphorus is recognized as one of the major
nutrients required by living organisms, involved in vital
physiological process. At the same time it can also be
considered as a pollutant if the concentration are high
under specific environmental conditions. It contributes to
228
increase eutrophication process of lakes and natural
waters (Usharani et al., 2009). The possible entry of this
ion into aquatic environment is through household
sewage water. The main sources of phosphorus released
into the environment include fertilizers, detergents,
cleaning preparation and boiler waters to which
phosphates are added for treatment (Pradyot, 1997). Bio-
treatment is a cost effective method for wastewater
before being discharged into the streams and rivers. Van
Loosdrecht et al., (1997) reported that biological
phosphate removal from wastewater is accepted because
of less cost (economic) and alternative to chemical
phosphate removal. According to Ioana et al. (2010),
Bacillus megatherium has bio-accumulative properties of
some heavy metals such as lead, arsenic, cadmium which
are used for biosolubilization of phosphate, silica etc.,
229
4.1.3.2 Nitrosomonas sp.
The results of Nitrosomonas treatment @ 1%
inoculum revealed that BOD decreased 46.34%. Various
other parameter changes are tabulated in table 6 page
420. The reduction of BOD of wastewater by
nitrosomonas was more than 46%. Hence, it was
considered as one of the essential microorganism in the
consortium for the bioremediation of sewage.
Nitrosomonas is a gram negative, rod shaped
aerobic bacterium having chemo-lithoautotrophic
properties. The strain was collected from National
Collection of Industrial Microorganisms (NCIM -5071)
and was used in the present study.
230
4.1.3.3 Nitrobacter
The treatment of wastewater by the addition of
Nitrobacter @ 1% revealed various changes in physico-
chemical parameters. BOD decreased by 41.43%, total
nitrogen decreased by 30.88%, ammonical-nitrogen
decreased by 40.31%, kjeldhal nitrogen decreased by
14.81%.
The results of other parameters are tabulated in table 7
page 421. Nitrobacter efficiently removed BOD of
wastewater by 41%, which is also illustrated by the
changes in the nitrite and nitrate values. Hence, it was
considered as one of the essential microorganism in the
consortium for the bioremediation of sewage.
Nitrobacter is a gram negative, rod shaped aerobic
bacterium having a flagella. The strain was collected
231
from National Collection of Industrial Microorganisms
(NCIM -5062) and was used in the present study. In
wastewater treatment the role of Nitrosomonas sps., and
Nitrobacter sps., cannot be separated as they contribute
to major physicochemical changes combined with in the
wastewater.
Min Jin et al., (2005), reported that the
ammonical nitrogen was removed with the efficiency
rate of 99% by using the organism Nitrobacter europea
at the rate of 2.5 X 106 and Nitrobacter winogradskyi at
the rate of 4.5 X 105. In nitrification, nitrosofying-
bacteria (e.g. Nitrosomonas) oxidize ammonia to nitrite
and nitrofying-bacteria (e.g. Nitrobacter) oxidise the
nitrite to nitrate. Dempsey et al., 2005 reported that these
bacteria obtain biochemical energy from the oxidation
step, and some of this energy is used to reduce carbon
232
dioxide to organic carbon, for incorporation into
biomass. Aside from requiring a reduced nitrogen
species and CO2, they also require similar nutrients to
other organisms, including molecular oxygen.
Harremoes (1982), reported that, in wastewater
treatment, nitrifying bacteria normally have to compete
for oxygen with the heterotrophic microbes responsible
for BOD oxidation. For example, in fixed biofilm
systems such as trickling filters, when the BOD
concentration is > 20 g m-3
, nitrification is limited by
oxygen availability.
According to Bock et al., (1986), nitrifying
bacteria are slow growing (under optimum conditions Td
= 8 h for Nitrosomonas, 10 h for Nitrobacter and are
therefore easily washed out of conventional suspension
233
culture systems, such as activated sludge, where the
prevailing conditions often result in doubling times of 1-
3 days. Hence, to operate a high rate nitrification
process, some form of biomass retention is required.
Although biomass retention is the chief
operational characteristic of traditional trickling filters, a
high cell concentration cannot be achieved because of
the large, inactive volume occupied by the biomass
support material. If the Td (doubling time of
microorganisms) is more than 4hours or 8 hours then the
quality of the wastewater may not change significantly in
a stipulated time. Hence it is essential to add suitable
external micro flora to the reactor to achieve parameters
of desired levels.
234
4.1.3.4 Pseudomonas denitrificans
The addition of inoculum Pseudomonas
denitrificans @ 1% for domestic wastewater revealed the
decrease in 43.3% and total nitrogen by 34.02%. Results
are tabulated in table 7 page 421. The removal efficiency
of BOD from wastewater by Pseudomonas denitrificans
was more than 43% and it clearly showed that the
removal of total nitrogen was 34%, in particular
ammonical nitrogen decreased by 38.73% from the
treatment system. Hence, it was considered as essential
microorganism in the consortium for the bioremediation
of sewage.
Pseudomonas denitrificans is a gram negative,
rod shaped, facultative anaerobic bacterium. The strain
was collected from National Collection of Industrial
235
Microorganisms (NCIM - 2038) and was used in the
present study.
The denitrifying microorganisms reduce nitrite
and nitrate to molecular nitrogen. Margardia et al.,
(2003) achieved 72-84% of nitrogen removal from the
treatment reactor with the help of denitrifying
microorganisms. The rate of the denitrification process is
influenced by the nature of the carbon sources, i.e., the
more easily degradable they are the faster the process
(Margarida et al 2003). Jerônimo (1998), recorded
maximum N2O production rates, in g N/g VSS/day, of
0.41 (10mgNO3-- N/L), 0.18 (30mg NO3
--N/L) and 0.19
(50mg NO3--N/L), with the process stabilizing at 15
hours, 15 hours and 30 hours respectively.
236
4.1.3.5 Chromatium sps.
The studies on bioremediation capabilities of
Chromatium sps., revealed that a decrease in BOD by
37.14%, hydrogen sulphide decreased by 34.38%. The
results of various other parameters are tabulated in table
8 page 422. The percentage reduction of BOD in the
wastewater by Chromatium sps., was more than 37% and
reduction of hydrogen sulphide levels upto 34% means
that it will be useful for bioremediation of sewage.
Hence, it was considered one of the microorganism of
sewage treatment consortium. Chromatium is a gram
negative, rod shaped, aerobic bacterium having
phototrophic properties. The strain was collected from
National Collection of Industrial Microorganisms
(NCIM - 2336) and was used in the present study.
Biebl and Pfenning (1979), observed the presence and
237
growth of purple sulphur bacteria in mero-mictic and
eutrophic lakes, sea water lagoons and oxidation ponds
treating sewage. Ptennig (1967), reported the appearance
of high populations of purple sulfur bacteria in a local
oxidation sewage lagoon receiving municipal and
industrial wastes. These organisms are capable of an
autotrophic mode of nutrition while utilizing sulfide and
certain other substrates as electron sources in the
photosynthetic process. Holm and Vennes (1970),
reported that 24.45 % decrease of BOD, 100% removal
of H2S from 2mg/litre concentration to zero in the
sewage treatment using purple sulfur bacterial
population. They also observed that acetate, an organic
substrate commonly utilized by purple sulfur bacteria, is
removed from the lagoon environment during
exponential increases in purple sulfur bacteria. Although
238
the test organisms have an optimum sulfide
concentration of 45 to 60 g/ml for growth, the organisms
will grow at lesser concentrations found in the lagoon.
Isachenko and Yegorova (1939); May and Stahl
(1967), reported that purple sulfur bacteria have long
been associated with anaerobic, sulfide containing zones
in lakes and more recently these organisms have been
associated with treatment facilities. These organisms
were shown to have the capabilities of utilizing certain
organic compounds as electron donors or as carbon
sources. However, the action of these organisms in the
lagoon environment has not previously been fully
explored.
239
4.1.3.6 Bacillus mucilaginosus
The studies on treatment efficiency of Bacillus
mucilaginosus revealed the reduction of BOD by 43.10%
and TSS decreased by 37.11%. Results of other
parameters are tabulated intable 8 page 422. The results
implies that it will be useful for bioremediation of
sewage. Hence, it was considered one of the
microorganism of sewage treatment consortium. Bacillus
mucilaginosus is a gram positive, aerobic, thick capsule
producing rod shaped bacterium with a flagellum (Deng
et al., 2003). The strain was collected from National Bio-
fertilizer Development centre (NBDC). It was renamed
as Paenibacillus mucilaginosus (Hu et al., 2010).
According to Deng et al., (2003) Bacillus
mucilaginosus produce heat stable polysachharide
240
biofloculant. Most bioflocculants are produced by
microorganisms during their growth periods (Kwon et
al., 1996; Nakata and Kurane, 1999; Shih et al., 2001).
Bacteria can utilize the nutrients in the culture medium
to synthesize high molecular weight polymers internally
within the cell under the action of specific enzymes and
these polymers can be excreted and exist in the medium
or on the surface of the bacteria as capsule. Hence, the
action of bacteria converts the simple substances in their
environment into complex polymers that can be used as
flocculant. In wastewater treatment, flocculation is an
easy and effective method of removing suspended solids
(SS). Many chemical flocculants, including aluminum
sulfate, ferric chloride and polyacrylamide (PAM), have
been widely used, although there are concerns about the
toxicity of these chemicals for recovering organics,
241
especially in the food and fermentation industries. Since
bioflocculants can be nontoxic, harmless and without
secondary pollution, they have a great potential for use
in those industries.
4.1.3.7 Lactobacillus acidophilus
The addition of inoculum Lactobacillus
acidophilus @ 1% for domestic wastewater treatment
revealed a decrease in BOD by 33.79%. The results of
other parameters are tabulated in table 9 page 423. The
removal efficiency of BOD from wastewater by
Lactobacillus acidophilus was more than 33% and it
clearly showed the formation of extracellular
polysaccharide (EPS). Hence, it was considered as
essential microorganism in the consortium for the
bioremediation of sewage. Lactobacillus acidophilus is
242
an aerobic, gram-positive, rod shaped bacterium. The
strain was collected from National Collection of
Industrial Microorganisms (NCIM - 2285) and was used
in the present study. The concept of effective
microorganisms (EM) containing yeasts, lactic acid
bacteria (Lactobacillus acidophilus), photosynthetic
bacteria, actinomycetes and other types of bacteria was
developed by Prof. Teruo (Higa, 1991). This concept of
beneficial microorganisms was extensively used for soil
& plant ecosystems to increase microbial diversity and
health of soil and plant. In the present study an attempt
was made to use the same concept of beneficial
microorganism for the bioremediation of sewage. Asha
and Sharma (2010), used Lactobacillus acidophilus for
the removal of As (III) from arsenic containing
wastewater.
243
4.1.3.8 Bacillus licheniformis
The studies on bioremediation capabilities of
Bacillus licheniformis revealed the reduction of BOD by
36.41%. The results are tabulated in table 9 page 423.
The percentage of reduction of BOD in the sewage by
Bacillus licheniformis was more than 36% and a
remarkable decrease of oil & grease (4.55%) means that
it will be useful for bioremediation of sewage. Hence, it
was considered one of the microorganism of sewage
treatment consortium. Bacillus licheniformis is gram
positive, rod shaped, thermophilic and spore forming
bacterium. The strain was collected form Microbial Type
Culture Collection Center (MTCC – 2450) and was used
in the present study. According to Drouin and Tyagi
(2007), municipal wastewater sludge (a rich source of
244
carbon, nitrogen, phosphorus and others nutrients
required for growth and production) can be use as a
substrate for Bacillus licheniformis. By applying this
concept to the present study, an attempt was made to use
Bacillus licheniformis. According to Shih et al. (2001),
Bacillus licheniformis can be used as bioflocculant.
Lipids (fats, oils and grease) are major organic matters in
municipal and some industrial wastewaters and can
cause severe environmental pollution.
High concentration of these compounds in
wastewater often causes major problems in biological
wastewater treatment process. Because of their nature
they form a layer of water surfaces and decrease oxygen
transfer rate in an aerobic process.
245
4.1.3.9 Rhodococcus terrae
The treatment of wastewater by the addition of
Rhodococcus terrae, @ 1% revealed the reduction in
BOD by 28.26% and an increase of H2S by 31.82%.
Results of other parameters are tabulated in table 10
page 424. The removal efficiency of BOD from
wastewater by Rhodococcus terrae., was 28% and it
showed that an increase of hydrogen sulphide (31.82%)
and low removal efficiency of COD (11.53%) may not
be helpful for wastewater treatment. Hence, it was not
considered as a candidate in the consortium for the
bioremediation of sewage. Rhodococcus terrae is a
gram-positive, aerobic, chemoorganotrophic bacterium.
The strain was collected from National Collection of
Industrial Microorganisms (NCIM -5126) and was used
in the present study. R. terrae were transferred to
246
Gordona genera and named as Gordonia terrae (Collins
et al., 1988; Stackebrandt et al., 1988). According to
Andrea et al. (2008), Gordonia strains are more useful as
biosurfectant. They are able to degrade n-heptadecane
completely in batch cultures.
Nocentini et al. (2000), reported that Gordonia
terrae shows a very appreciable capability of degrading
pristane and squalene, which, for their high degree of
branching, are considered extremely recalcitrant to
biodegradation and often remain in the environment as
residual contaminants after bioremediation. Ron and
Rosenberg (2001), reported that Gordonia sp. shows a
complex change in cell surface properties during growth
on hydrocarbons. These strains can use surface active
compounds to regulate their cell surface properties to
attach and detach from surfaces such as hydrocarbons.
247
By the presence of biosurfectant properties the
microorganisms Rhodococcus terrae was selected for the
study. But the results were not promising by using the
strain. Even though the strain is capable of degrading
aromatic compounds, its role is beyond the scope of the
present study. Hence it was not considered as candidate
for the bioremediation of domestic wastewater.
4.1.3.10 Thiobacillus ferrooxidans
The results of Thiobacillus ferrooxidans
treatment @ 1% inoculum revealed a slight decrease in
BOD by 5.23% whereas COD increased by 0.2%. The
results of various other parameters are tabulated in table
10 page 424. The removal efficiency of BOD from
wastewater by Thiobacillus ferrooxidans was absent and
it was increased by 5.23% and overall performance for
248
removal of pollutants from sewage was also not at an
acceptable mode. Hence, it was not considered as a
candidate of the consortium for the bioremediation of
sewage. Thiobacillus ferrooxidans is a gram-negative,
rod shaped, motile and aerobic bacterium and grows best
at pH range of 1.5 – 2.5. The strain which was collected
form Microbial Type Culture Collection Center (MTCC
- 2361) was used in the present study. According to
Karger (2005), Thiobacillus flourishes in mud, bogs,
sewage, brakish springs and acid mines. It derives
energy from oxidation of sulphur compounds such as
elemental suphur, sulphides and thiosulphate converting
the toxic compounds into non-toxic sulphate that are
useful to other microorganisms. Van langerhove et al.
(1986) and Kyeoung et al. (1992), stated that
Thiobacillus sps., are responsible for degradation activity
249
of sewage. As per the previous reports the organism
Thiobacillus ferrooxidans is capable of converting
various toxic compounds in the sewage, the overall
performance is not promising to continue the organism
in the consortium. The variation in the pH might be one
reason for performance failure in sewage bioremediation.
Significance of bacterial inoculation
According to Amit et al. (2003), the bacterial
inoculation from external source is essential. Without a
start up culture, requires a long period of time and may
therefore cause significant losses and environmental
harm due to discharge of nitrogen rich effluents. They
reported that an external start up nitrifying enrichment
culture performed similarly to the natural bacterial
population of an established pond biofilter and superior
250
to the performance of similar biofilters without a start up
culture (control) by demonstrating a laboratory scale
setup (7-l aquaria with shrimp and fish).
Preparation of Consortium
It is evident that the role of Nitrosomonas &
Nitrobacter sps in sewage degradation is more.
Moreover, the Td (doubling time) for these two
organisms are also more than 8 hours. Hence the
concentration of these two microorganisms were doubled
i.e., at the rate of 20% each and remaining six
microorganisms at the rate of 10% each. Experiments
were conducted using this ratio.
Significance of consortium
Biotreatment processes generally involve mixed
carbon energy substrates and multiple nutrients serving
251
each particular physiological requirement, clearly
emphasizing a need for concept expansion in order to
allow such processes to be evaluated. The ultimate
performance of mixed process cultures employed in
biotreatment process depends on both intra-consortium
and inter-consortia interactions within the overall
community. This comprises the process culture with
respect to imposed process operating and environmental
conditions. Two distinct situations occur when the
functioning of mixed cultures for specific pollutant
biodegradation under essentially aerobic conditions is
considered. These involve either the employment of a
culture in which a complementary sequence of catabolic
activities from several associated strains is harnessed in
order to generate a complete degradative pathway for the
pollutant under consideration or employment of a culture
252
in which the fastidiousness of the primary pollutant
degrading strain is diminished by the actions of several
associated ancillary strains. Both types of mixed culture
can result from enrichments but the former can also
result from constitution using independently isolated
strains from diverse sources. In the case of the latter,
reconstitution can only follow complete fractionation of
a mixed enrichment culture. In the case of the former
type of mixed culture, the number of strains necessary
for the constitution of the complete degradative pathway,
in laboratory situations, reduce as a result of plasmid
transfer (Hartmann et al., 1979). And such occurrences
during the biodegradation of strictly xenobiotic
compounds have encouraging proposals for the use of
genetically manipulated monocultures as process
cultures for waste treatment process (Fujita and Ike,
253
1994). However, the development of such concepts is
that the transfer of a characteristic, i.e., a portion of a
degradative pathway, allows neither the construction of
entirely novel pathways nor the development of novel
enzyme specificities. Furthermore, manipulation
enhances fastidiousness and reduces strain
competitiveness and performance under actual operating
conditions.
4.1.4 Reactor design
Open type reactors were designed to
accommodate the volume of 50 litres of sewage sample
and about 16 litres of air. 50 litres of sewage sample was
considered as working sample. Four reactors were
fabricated with pre determined size of 60 cm length, 30
cm breadth and 37 cm height. One reactor was used as
254
blank and remaining three were used for treatment as
triplicate for sewage sample. The experimental design
was batch type and work was done one after another for
each variable of the work. 50 litres volume of sewage
sample was transferred to reactor using rubber hose pipe
from sewage tank.
4.1.5 Optimization studies
The optimization studies revealed that the
percentage of removal efficiency was more at a
particular concentration of every parameter. For each
parameter the condition at maximum removal efficiency
obtained was taken into consideration as optimized
condition of that parameter for further experiments.
255
4.1.5.1 Optimization of concentration of inoculums
The results of removal efficiency of pollutant in
terms of BOD in the domestic wastewater at various
concentration of inoculum of consortium were tabulated.
It was observed that maximum BOD removal efficiency
(%) was obtained with 0.2 % inoculum concentration.
The studies on bioremediation capabilities of
consortium inoculation in terms of BOD reduction was
56.12% at the concentration of 0.05% (or) 500 ppm,
61.55% at the concentration of 0.1%, 63.80% at the
concentration of 0.2%, 64.44% at the concentration of
0.3%, 65.13% at the concentration of 0.4% and 66.16%
at the concentration of 0.5%. Results of various other
physico-chemical parameters are tabulated (Table 11 –
13, pages 425-427).
256
As the quantity of wastewater is more, it is found
that using more than 0.5% inoculum is not feasible. It is
believed that instead of using high concentration of
inoculum we have to screen, isolate and enumerate high
efficiency strains of microorganisms. Nadirah et al.
(2008), reported a 61% removal of BOD, 97% COD,
86% removal of ammonia, 71% removal of total
suspended solids, 50% removal of nitrate and 53%
removal of oil and grease using Pseudomonas putida,
Pseudomonas fluorescence, Xanthobacter sps., and
Rhodoccus sps., for treatment of domestic wastewater.
Min Jin et al. (2005), reported a 91.7% COD removal
and 99% ammonical-nitrogen removal efficiency using
nitrosomonas europea, nitrobacteria windogradskyi,
Bacillus licheniformis, Bacillus megatherium, Bacillus
sphaericus for the treatment of domestic sewage and
257
membrane bioreactors in 5 hours hydraulic retention
time. Balaji et al. (2005), reported a 71% of BOD
removal using cow dung as the source of
microorganisms with dosing of 3% and 18 hours HRT
during the experiments conducted for treatment of
tannary industry wastewater. According to Prasad and
Manjunath (2010), lipid content removal and 99% of
BOD removal can be obtained using 1% of bacterial
consortium. Deng et al.(2003), reported 85.5% of TSS
removal and 68.5% COD removal using 0.01% of
Bacillus mucilaginosus as inoculant for biofloculating
material for the treatment of starch wastewater.
Graphical representation (fig 1, page 510) is made for
various physico-chemical parameters like total
suspended solids, chemical oxygen demand, biochemical
oxygen demand, nitrogen, phosphorus and hydrogen
258
sulphide, because they are major pollution parameters in
which decrease / increase is the index of treatment
process.
4.1.5.2 Optimization of hydraulic retention time
(HRT)
The maximum removal efficiency of BOD was
obtained with 12 hours HRT. The results of removal
efficiency of BOD at different HRT are tabulated (Table
14 – 16, pages 428 - 430). The treatment of wastewater
by the addition of 0.2% inoculum results in the decrease
of BOD by 32.11% for 4 hours HRT. It was observed
that 46.42% of BOD was decreased for 8 hours HRT.
60.87% of BOD was removed for 12 hours HRT. For 16
hours HRT BOD was decreased by 62.25%. For 20
hours HRT BOD decreased by 63.87% and BOD was
259
63.9% for 24 hours HRT. Results of various other
physico-chemical parameters are tabulated. Hashmi
Imran (2007), achieved the mean removal efficiency of
COD at the rate of 87% after 24 hours of treatment using
activated sludge. Chuang et al. (1997), reported that high
HRT may helps in the production of heterotrophic
biomass and finally results in readily biodegradable
COD from the sewage. Abbas et al. (2008), proved the
denitrification ability of the bioreactor using
immobilized methyl cellulose at a very low hydraulic
retention time i.e., 3 hours. Dempsey et al. (2005),
studied the performance of pilot scale expanded bed for
removal of ammonia, suspended solids and
carbonaceous COD using activated sludge for 42 days
operation with low loading rates. They obtained the
results of wastewater treatment i.e., 56% BOD removal
260
and 62% of TSS removal. Shanableh et al. (1997), stated
that high HRT helps the polyphosphate accumulating
biomass to dominate the bioreactor system. Total
nitrogen removal also increased with increase of HRT.
Practically wastewater treatment plants have to be
designed to meet a number of conditions that are
influenced by flow rates, wastewater characteristics and
combination of both. The development and forecasting
of average daily flow rates are necessary to determine
the design capacity as well as the hydraulic requirements
of the treatment system. In the present study, 0.2% (2000
ppm) inoculum rate and 12 hours HRT were considered
as optimized to use for further experimentations.
Graphical representation of HRT effect was illustrated in
fig 2, page 511.
261
4.2 Chapter II
Preparation of biofilter material
All the materials were washed with distilled
water and dried for 24 hours. Later materials were
subjected to autoclaving @ 121°C for 20 minutes. Nylon
threads and plastic balls were wiped with ethanol and
used in the present study. Experiments were conducted
using natural filter media as material. Granite stones of
size 2cm X 2cm X 0.3cm height of equal sized cube
shapes were used for present study (Image 3, page 503).
Volume of the stone was calculated using the
formula
V = l x b x h, and it was observed that each stone has a
volume of 1.2 cm3. Volume of the reactor was calculated
and it was observed that it has 66600 cm3
(or) 0.066 m3.
262
Based on the volume of the reactor, various volumes of
stones i.e., 4167 pieces (10% of working volume), 8333
pieces (20% of volume), 12500 pieces (30% of volume)
and 16667 pieces (40% of volume) were used in the
present study. Surface area of the stone was determined
and it was 10.4 cm2 for each stone.
The specific surface area of stone was determined
by dividing the surface area with volume of the stone
and converted to meter scale and it was 866.67 m2/m
3.
The concentration of inoculum (0.2%) and 12 hours of
hydraulic retention time were optimized for domestic
wastewater treatment in the previous chapter. They were
considered as standard to determine the effect of volume
of stone as biofilter material.
263
4.2.1 Effect of various volumes of granite chips as
biofilter material in the presence of 0.2%
inoculum and 12 hours HRT
Effect of various volumes of stone (granite chips)
as biofilter material along with 0.2% consortium and 12
hours HRT were studied. It was observed that the
reduction of BOD was 62.14% in the presence of 10%
volume of filter material (granite chips). 57.3% of BOD
was decreased in 20% volume of filter material. 61.88%
of BOD was removed with 30% volume of filter material
and 62.14% of BOD was decreased in the presence of
40% volume of filter material. Results of various other
physico-chemical parameters are tabulated (Table 17 –
18, page 431-432).
After the completion of experiments with various
volumes of stones as biofilter material, it was noticed
264
that there was no significant variation in the removal
efficiency of pollutant. The results were more or less
similar to that of experiments without filter material.
Graphical representation is illustrated in fig 3 page 512 .
Further experimentation were continued by using 10%
volume of stones as optimized volume of biofilter
material, 0.2% inoculum at various hydraulic retention
times like 8 hours, 9 hours, 10 hours, 11 hours and 12
hours to determine the effect of hydraulic retention time
in the presence of stone as biofilter material.
4.2.2 Effect of various HRT’s in the presence of 10 %
volume of stones as biofilter material, 0.2%
inoculums
The maximum removal efficiency of BOD was
obtained at 12 hours of hydraulic retention time. The
results of removal efficiency of biochemical oxygen
265
demand at different HRTs are tabulated. The treatment
of wastewater by the addition of 0.2% inoculum and
10% volume of stones as biofilter material revealed that
the reduction of BOD by 46.19% for 8 hours HRT,
48.44% for 9 hours HRT, 51.98% for 10 hours HRT,
54.04% for 11 hours HRT and 60.94% for 12 hours
HRT. Results of various other physico-chemical
parameters are tabulated (Table 19 – 21, page 433 - 435).
After completion of experimentation with 10% volume
of stones as biofilter material, 0.2 % inoculum at various
HRTs, it was noticed that volume of filter material and
HRT did not show any significant changes during the
treatment process when compared to various HRTs in
the presence of 0.2 % inoculum without filter material.
Graphical illustration was made and is represented in fig
4 page 513. Further experimentation was conducted to
266
determine the viability and increase of performance of
filter material. Experiments were conducted for 60 days
and samples of wastewater before and after treatment
were analyzed at every 10 day interval.
4.2.3 Effect of Time period
The maximum removal efficiency of biochemical
oxygen demand (62.11%) was obtained after 40 days of
time period and continued thereafter onwards. The
results of removal efficiency of biochemical oxygen
demand at different time periods are tabulated. Effect of
10 days time period on 10% volume of stone as biofilter
material along with 0.2% consortium as inoculum & 12
hours HRT for domestic wastewater treatment in terms
of BOD removal revealed that the reduction of BOD by
61.39% for 10 days time period, 60.99% for 20 days
267
time period, 62.11% for 30 days time period, 61.73% for
40 days time period, 62.08% for 50 days time period and
62.11% for 60 days time period. Results of various other
physico-chemical parameters are tabulated (Table 22 –
24, page 436-438). After completion of experimentation
with 10% volume of stones as biofilter material, 0.2 %
inoculum and 12 hours hydraulic retention time at
various time periods, it was noticed that a slight increase
in the efficiency removal of pollutants increased after 40
days of operation, when compared to various HRTs in
the presence of 0.2 % inoculum without filter material.
Graphical illustration was made and it is represented in
fig 5 page 514.
In support of our findings, Metcalf and Eddy,
(1995), reported that the most commonly used filter
268
material for biofiltration is high quality granite stones
and furnace slag. They suggested that uniform size of
stone ranging from 3-4 inches or 75-100 mm is suitable
material for filtration process.
Valentine et al. (2010), reported that 98%
removal of total coliforms and fecal streptococci was
achieved after 14 days of hydraulic retention time for
pathogen reduction in rural water supply using granite
gravel of size 0.15 sq.mm as biofilter media. They
suggested that the pathogen removal was more in granite
gravel filter media when compared to sand bed filter and
zero valant iron (ZVI) filters. Valentine et al., (2010)
also reported that the biofilter made up of granite chips is
responsible for production of natural organic matter is
more at the time of 28 days. Sammaiah et al., (1991),
269
reported COD removal in the range of 62.8 - 91.3 %
with 51 % granite stone bed porosity as mobilizing
media in upflow anaerobic filter process. Tyrrel et al.
(2008), reported 7% removal efficiency of COD and
70% removal of ammonical nitrogen in the presence of
granite stone as filter material and stated that granite
chip shows resilient response i.e., efficiency initially dips
and then recovers after a period of time and gradually
improves. They studied the nature and removal
efficiency capabilities of granite stone extensively. They
used granite stone as biofilter material along with two
materials compost and over size for the bioremediation
of leachate. They suggested that chipped granite is a
traditional medium used in the construction of biofilters
for the treatment of urban wastewater. In the present
study, the overall performance of granite stone was very
270
low when compared with the experimentation without
the addition of filter materials. At 30 days time period,
the granite stone biofilter resulted in slight decrease (2-
3%) in removal efficiency. Later after 40 days time
period the removal efficiency gradually increased.
4.3 Chapter III
Clay balls as biofilter material
Experiments were conducted using natural
processed filter media as material. Clay balls and
sintered glass cylinders (air stone) were used in the
present study. Clay balls of radius 2 cm of equal sized
sphere shaped balls were used for present study (Image
4, page 504). Volume of the clay ball was calculated
using formula V = 4/3πr3, and it was observed that each
clay ball had a volume of 33.49 cm3. Volume of the
271
reactor was calculated and it was observed that it was
66600 cm3
(or) 0.066 m3. Based on the volume of the
reactor, various volumes of clay balls i.e., 149 pieces
(10% of working volume), 299 pieces (20% of volume),
448 pieces (30% of volume) and 597 pieces (40% of
volume) were used in the present study. Surface area of
the clay ball was determined and it was 50.24 cm2 for
each clay ball. The specific surface area of clay ball was
determined by dividing the surface area with volume of
the clay ball and converted to meter scale and it was
150.0 m2/m
3.
4.3.1 Effect of various volumes of clay balls as
biofilter material along with 0.2% consortium
and 12 hours hydraulic retention time
The concentration of inoculum (0.2%) and 12
hours of HRT were optimized for domestic wastewater
272
treatment in the previous chapter. They were considered
as standard to determine the effect of volume of clay
balls as biofilter material. Effect of various volumes of
clay balls as biofilter material along with 0.2%
consortium and 12 hours HRT were studied. The
reduction BOD was 64.11% in the presence of 10%
volume of filter material (clay balls), 67.82% BOD
removal was observed with 20% volume of filter
material. BOD was decreased by 71.79% with 30%
volume of filter material and it was 72.05% in the
presence of 40% volume of filter material. Results of
various other physico-chemical parameters are tabulated
(Table 25 – 26, page 439 - 440).
After the completion of experiments with various
volumes of clay balls as biofilter material, it was noticed
273
that there was a significant variation in the removal
efficiency of pollutant. The results were observed to be
useful for sewage treatment process. Graph was
illustrated and is represented in fig 6 page 515. Further
experimentation was continued by using 30% of clay
balls as optimized volume of biofilter material, 0.2%
inoculum at various HRT’s like 8 hours, 9 hours, 10
hours, 11 hours and 12 hours to determine the effect of
HRT in the presence of clay balls as biofilter material.
4.3.2 Effect of various HRT’s in the presence of 30 %
volume of clay balls as biofilter material, 0.2%
inoculum
The maximum removal efficiency of BOD was
obtained after 10 hours of hydraulic retention time. The
treatment of wastewater by the addition of 0.2%
inoculum and 30% volume of clay balls as biofilter
274
material revealed the reduction of BOD by 60.31% for 8
hours HRT, 65.35% for 9 hours HRT, 69.57% for 10
hours HRT, 69.93% for 11 hours HRT and 71.13% for
12 hours HRT. Results of various other physico-
chemical parameters are tabulated (Tables 27 – 29, page
441 - 443).
After completion of experimentation with 30%
volume of clay balls as biofilter material, 0.2 %
inoculum at various HRTs, it was noticed that 10 hours
HRT shows significant changes during the treatment
process. Hence, 10 hours was considered as optimized
HRT. Graphical representation was made and illustrated
in fig 7, page 516. Further experimentation was
conducted to determine the viability and increase of
performance of filter material. Experiments were
275
conducted for 60 days and samples of wastewater before
and after treatment were analyzed for every 10 day
interval.
4.3.3 Effect of Time period
The maximum removal efficiency of BOD was
obtained up to 30 days of time period. The results of
removal efficiency of BOD at different time periods are
tabulated. Effect of 10 days time period on 30% volume
of clay balls as biofilter material along with 0.2%
consortium as inoculum & 10 hours HRT for domestic
wastewater treatment in terms of BOD removal revealed
that the reduction of BOD by 71.04% for 10 days time
period, 71.90% for 20 days time period, 72.92% for 30
days time period, 68.35% for 40 days time period,
62.04% for 50 days time period and 62.74% for 60 days
276
time period. Results of various other physico-chemical
parameters are tabulated (Table 30 – 32, page 444 - 446).
After completion of experimentation with 30%
volume of clay balls as biofilter material, 0.2 %
inoculum and 10 hours hydraulic retention time at
various time periods, it was noticed that the efficiency
removal of BOD and other pollutants were increased
upto 30 days of operation. Later it was observed that a
decrease of efficiency removal of BOD and other
pollutants for 40 days, 50 days & 60 days. Graph was
illustrated and represented in fig 8 page 517. Hence, 30
days of time period can be consider as an optimized time
period for the treatment process of domestic wastewater.
Meyer et al. (2000), reported that 14.5% of
phosphorus removal efficiency, 28.85% COD removal
277
efficiency and increased concentration of suspended
solids from 0.62 gm/litre to 1.78 gm/litre using sewage
sludge mixed clay balls in 70:30 ratio as biofilter media
for sewage treatment. They used 65% volume of filter
material with 24 hours HRT.
Petter et al., (2010), used Filtralite®P a clay
aggregates as a biofilter material and achieved >80%
removal of organic matter measured as biochemical
oxygen demand (BOD), >94% of total phosphorus (TP)
and 32 to 66% total nitrogen (TN) and the ammonia
(NH4) removal ranged from 38 to 80%. They used the
biofilter which consisted of a 0.6m deep filter of light-
weight clay aggregates (Filtralite®P) in the size range of
2–10mm. In the present study, the BOD removal
278
efficiency ranged from 60-73% and it found to be
significant for usage as filter material.
Sintered glass as filter material
Experiments were conducted using natural
processed filter media as material. Sintered glass
cylinders of radius of radius 0.7 cm and height of 2.6 cm
of equal sized cylinder shaped sintered glass material
was used for present study (Image 5, page 505 ). Volume
of the sintered glass cylinder was calculated using
formula V = πr2h, and it was observed that each sintered
glass cylinder had a volume of 4.0 cm3. Based on the
volume of the reactor, various volumes of sintered glass
cylinders i.e., 1250 pieces (10% of working volume),
2500 pieces (20% of volume), 3750 pieces (30% of
volume) and 5000 pieces (40% of volume) were used in
279
the present study. Surface area of the sintered glass
cylinder was determined and it was 14.51 cm2 for each
sintered glass cylinder. The specific surface area of
sintered glass cylinder was determined by dividing the
surface area with volume of the sintered glass cylinder
and converted to meter scale and it was 362.64 m2/m
3.
4.3.4 Effect of various volumes of sintered glass
cylinders as biofilter material along with 0.2%
consortium and 12 hours hydraulic retention
time
Effect of various volumes of sintered glass
cylinders as biofilter material along with 0.2%
consortium and 12 hours HRT were studied. The
reduction of BOD was 64.85% in the presence of 10%
volume of filter material (sintered glass cylinders). It
was 68.57% with 20% volume of filter material. It was
280
observed that the removal of BOD was 72.65% with
30% volume of filter material and it was 72.55% in the
presence of 40% volume of filter material. Results of
various other physico- chemical parameters are tabulated
(Table 33 – 34, page 447 - 448). After the completion of
experiments with various volumes of sintered glass
cylinders as biofilter material, it was noted that there was
a significant variation in the removal efficiency of
pollutants. The results were observed to be useful for
sewage treatment process (fig 9, page 518). Further
experimentation was continued using 30% of sintered
glass cylinders as optimized volume of biofilter material,
0.2% inoculum at various hydraulic retention times like
8 hours, 9 hours, 10 hours, 11 hours and 12 hours to
determine the effect of hydraulic retention time in the
presence of sintered glass cylinders as biofilter material.
281
4.3.5 Effect of various HRT’s in the presence of 30 %
volume of sintered glass cylinders as biofilter
material, 0.2% inoculum
The maximum removal efficiency of BOD was
obtained after 10 hours of HRT. The results of removal
efficiency of BOD at different HRTs are tabulated. The
maximum removal efficiency of BOD was obtained after
10 hours of HRT. The treatment of wastewater by the
addition of 0.2% inoculum and 30% volume of sintered
glass cylinders as biofilter material revealed the
reduction of BOD by 60.42% for 8 hours HRT, 63.50%
for 9 hours HRT, 70.49% for 10 hours HRT, 71.08% for
11 hours HRT and 71.23% for 12 hours HRT. Results of
various other physico-chemical parameters are tabulated
(Table 35 – 37, page 449 - 451).
282
After completion of experimentation with 30% volume
of sintered glass cylinders as biofilter material, 0.2 %
inoculum at various HRTs, it was noticed that 10 hours
HRT shows significant changes during the treatment
process. Hence, it was considered that 10 hours HRT is
optimized HRT. Graphical representation is illustrated in
fig 10, page 519. Further experimentation was conducted
to determine the viability and increase of performance of
filter material. Experiments were conducted for 60 days
and samples of wastewater before and after treatment
were analyzed at every 10 day interval.
4.3.6 Time period
The maximum removal efficiency of BOD was
obtained up to 30 days of time period. Effect of time
period on 30% volume of sintered glass cylinders as
biofilter material along with 0.2% consortium as
283
inoculum & 10 hours HRT for domestic wastewater
treatment in terms of BOD removal revealed that the
reduction of BOD by 71.61% for 10 days time period,
72.04% for 20 days time period, 73.06% for 30 days
time period, 67.97% for 40 days time period, 61.96% for
50 days time period and 63.13% for 60 days time period.
Results of various other physico-chemical parameters are
tabulated (Table 38 – 40, page 452 - 454).
After completion of experimentation with 30%
volume of sintered glass cylinders as biofilter material,
0.2 % inoculum and 10 hours HRT at various time
periods, it was noticed that the efficiency removal of
BOD and other pollutants were increased up to 30 days
of operation. Later a decrease of efficiency removal of
BOD and other pollutants was observed for 40 days, 50
284
days & 60 days (fig 11, page 520). Hence, 30 days of
time period can be consider as optimized time period for
the treatment process of domestic wastewater.
4.4. Chapter IV
Experiments were conducted using natural
biogenic material as material. Corn cobs and wood chips
were used in the present study. Corn cobs were collected
from local maize fields and wood chips from the local
carpenter. Uneven tips of both the biogenic materials
were made to even using a saw machine.
Corn cobs as filter material
Corn cobs of outer radius 1.25 cm, inner radius
of 0.5 cm and height of various sizes ranging from 5 cm
285
to 10 cm of hollow cylindrical shaped material were
used in the present study (Image 6 & 7, page 506). The
mean height of cobs was measured and it was 7.6 cm.
Volume of the hollow cylindrical corn cobs was
calculated using formula V = π h (R2- r
2), and it was
observed that each hollow cylindrical corn cob had a
volume of 31.32 cm3. Based on the volume of the
reactor, various volumes of hollow cylindrical corn cobs
i.e., 160 pieces (10% of working volume), 319 pieces
(20% of volume), 479 pieces (30% of volume) and 639
pieces (40% of volume) were used in the present study.
Surface area of the corn cob was determined and it was
327.68 cm2 for corn cob having the outer diameter of 2.5
cm, inner diameter of 1cm and a mean height of 7.6 cm.
The specific surface area of corn cob was determined by
dividing the surface area with volume of the corn cob
286
and converted to meter scale and it was 1046.17 m2/m
3.
Prior to using hollow cylindrical corncobs, experiments
were conducted using cylindrical corn cobs without
removing central core material i.e., parenchyma. Results
were not promising using cylindrical cobs when
compared to hollow cylindrical corn cobs.
4.4.1. Effect of various volumes of corn cobs as
biofilter material along with 0.2%
consortium and 12 hours HRT were
determined.
The results showed the reduction of BOD by
58.08% in the presence of 10% volume of corn cobs and
51.98% in the presence of 20% volume of filter material
(Table 41, page 455). It was observed that the addition of
corn cobs at the rate of 10% & 20% volume to the
treatment system, the BOD and other parameters were
287
increased when compared to removal efficiency of
microorganisms @ 0.2% and 12 hours HRT. Hence,
further experimentation was continued by removing the
central medullary portion of the corn cob. It comprises of
soft parenchymatous tissue. After removal of medulla,
the corn cob becomes central hollow cylinder and
surface area was calculated and used in the present
study.
The results of various volumes of corn cobs
(hollow cylindrical) as biofilter material along with 0.2%
consortium and 12 hours hydraulic retention time for the
treatment of domestic wastewater treatment revealed that
a decrease in the BOD by 67.34% in the presence of 10
% volume of hollow cylindrical corn cobs. BOD was
removed by 74.9% with 20% volume of filter material.
288
Removal of BOD by 76.26% occurred with 30% of filter
material and 78.8% of BOD was removed in the
presence of 40% filter material (Table 42 – 43 page 456
& 457). After the completion of experiments with
various volumes of hollow cylindrical corn cobs as
biofilter material, it was noticed that there was a
significant variation in the removal efficiency of
pollutant. The results were observed to be useful for
sewage treatment process. Graph was illustrated and it is
represented in fig. 12 page 521. Further experimentation
was continued by using 20% of hollow cylindrical corn
cobs as optimized volume of biofilter material, 0.2%
inoculum at various HRT’s like 8 hours, 9 hours, 10
hours, 11 hours and 12 hours to determine the effect of
HRT in the presence of hollow cylindrical corn cobs as
biofilter material.
289
4.4.2 Effect of various HRT’s in the presence of 20
% volume of hollow cylindrical corn cobs as
biofilter material, 0.2% inoculum
The maximum removal efficiency of BOD was
obtained after 9 hours of HRT. The results of removal
efficiency of BOD demand at different HRTs are
tabulated. The treatment of wastewater by the addition of
0.2% inoculum and 20% volume of hollow cylindrical
corn cobs as biofilter material for various HRT’s
revealed the reduction of BOD by 67.03% for 8 hours of
HRT, 78.14% for 9 hours HRT, 78.1% for 10 hours
HRT, 78.63% for 11 hours of HRT and 81.76% for 12
hours of HRT (Table 44 – 46, page 458 - 460).
After completion of experimentation with 20%
volume of hollow cylindrical corn cobs as biofilter
material, 0.2 % inoculum at various HRTs, it was
290
noticed that 9 hours HRT showed significant changes
during the treatment process. Hence, 9 hours HRT was
considered as optimized HRT (fig 13, page 522). Further
experimentation was conducted to determine the
viability and increase of performance of filter material.
Experiments were conducted for 60 days and samples of
wastewater before and after treatment were analyzed for
every 10 day interval.
4.4.3 Time period
The maximum removal efficiency of BOD was
obtained up to 40 days of time period. The results of
removal efficiency of BOD at different time periods are
tabulated. Effect of time period on 20% volume of corn
cobs as biofilter material along with 0.2% consortium as
inoculum and 9 hours HRT for domestic wastewater
291
treatment in terms of BOD removal revealed the
reduction of BOD by 83.05% for 10 days time period. It
was observed that 83.15% BOD was removed in 20 days
time period, 84.52% in 30 days time period, 84.72% in
40 days time period, 81.38% in 50 days time period and
80.02% for 60 days time period. Results of various other
physico-chemical parameters are tabulated (Table 47 –
49, page 461 - 463). After completion of
experimentation with 20% volume of hollow cylindrical
corn cobs as biofilter material, 0.2 % inoculum and 9
hours HRT at various time periods, it was noted that the
efficiency removal of BOD and other pollutants
increased up to 40 days of operation. Later it was
observed that a decrease of efficiency removal of BOD
and other pollutants occurred for 50 days & 60 days.
Graphical representation was made and illustrated in fig
292
14, page 523. Hence, 40 days of time period can be
considered as optimized time period for the treatment
process of domestic wastewater. According to Jignesh et
al. (2008), about 10504 MT of maize is produced in
India annually and the cobs are thrown as a waste. Hence
cobs will be available free of cost and can be utilized in
domestic wastewater treatment.
Wood chip as biofilter material
Experiments were conducted using natural
biogenic filter media like wood chip as filter material.
Wood chips of size 8.4 cm X 0.8 cm X 0.7cm, (length X
breadth X height) of equal sized rectangular cube shaped
wood pieces were used for the present study (Image 8,
page 507). Volume of the wood chip was calculated
using formula V = l x b x h, and it was observed that
293
each wood chip had a volume of 4.7 cm3. Based on the
volume of the reactor, various volumes of wood chips
i.e., 1063 pieces (10% of working volume), 2126 pieces
(20% of volume), 3189 pieces (30% of volume) and
4252 pieces (40% of volume) were used in the present
study. Surface area of the wood chip was determined and
it was 26.32 cm2 for each wood chip. The specific
surface area of wood chip was determined by dividing
the surface area with the volume of the wood chip and
converted to meter scale and it was 559.52 m2/m
3.
4.4.4 Effect of volume of wood chips
The results of various volumes of wood chips as
biofilter material along with 0.2% consortium and 12
hours HRT for the treatment of domestic wastewater
treatment revealed a decrease in the BOD by 67.14% in
294
the presence of 10 % volume of filter material (wood
chips). 70.16% of BOD was removed with 20% volume
of filter material. 74.66% of BOD was removed in the
presence of 30% filter and 76.97% with 40% filter
material (Table 50 – 51, page 464 & 465). After the
completion of experiments with various volumes of
wood chips as biofilter material, it was noted that there
was a significant variation in the removal efficiency of
pollutant. The results were observed to be useful for
sewage treatment process (fig 15, page 524). Further
experimentation was continued by using 30% of wood
chips as optimized volume of biofilter material, 0.2%
inoculum at various HRT’s like 8 hours, 9 hours, 10
hours, 11 hours and 12 hours to determine the effect of
hydraulic retention time in the presence of wood chips as
biofilter material.
295
4.4.5 Effect of various hydraulic retention times in
the presence of 30% volume of wood chips as
biofilter material, 0.2% inoculum at various
HRTs
The maximum removal efficiency of BOD was
obtained after 10 hours of hydraulic retention time. The
treatment of wastewater by the addition of 0.2%
inoculum and 30% volume of wood chips as biofilter
material for various HRT’s revealed the reduction of
BOD by 66.84% for 8 hours of HRT, 71.45% for 9 hours
HRT, 73.91% for 10 hours HRT, 78.38% for 11 hours of
HRT and 80.25% for 12 hours of HRT (Table 52 – 54,
page 466 - 468). After completion of experimentation
with 30% volume of wood chips as biofilter material, 0.2
% inoculum at various HRTs, it was noted that 10 hours
HRT showed significant changes during the treatment
process. Hence, 10 hours HRT was considered as
296
optimized HRT (fig 16, page 525). Further
experimentation was conducted to determine the
viability and increase of performance of filter material.
Experiments were conducted for 60 days and samples of
wastewater before and after treatment were analyzed for
every 10 day interval.
4.4.6 Time period
The maximum removal efficiency of BOD was
obtained up to 50 days of time period. The results of
removal efficiency of BOD at different time periods are
tabulated. Effect of time period on 30% volume of wood
chips as biofilter material along with 0.2% consortium as
inoculum & 10 hours HRT for domestic wastewater
treatment in terms of BOD removal revealed the
reduction of BOD by 80.19% for 10 days time period,
297
81.01% for 20 days time period, 82.74% for 30 days
time period, 83.52% for 40 days time period, 83.53% for
50 days time period and 78.99% for 60 days time period.
Results of various other physico-chemical parameters are
tabulated (Table 55 – 57, page 469 - 471). After
completion of experimentation with 30% volume of
wood chips as biofilter material, 0.2 % inoculum and 10
hours HRT at various time periods, it was noted that the
efficiency removal of BOD and other pollutants were
increased up to 50 days of operation. Later a decrease of
efficiency removal of BOD and other pollutants was
observed for 60 days (fig 17, page 526). Hence, 50 days
of time period can be considered as optimized time
period for the treatment process of domestic wastewater.
Miao et al. (2005), reported that 97% removal efficiency
of rapeseed oil smoke by pseudomonas sps., with the
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help of platane wood chips as biofilter material. Saliling
et al. (2007), reported that the denitrification rate for
wood chips as biofilter media was 1.36kg NO3-N/m3/d.
In conformance with our observation, Wolverton et al.
(1983), compared various kinds of filter material which
are plant free including reeds, cattail, rush and bamboo.
They reported that bamboo filter is more efficient than
plant free system by reducing 49% of ammonical
nitrogen in 6 hours and 76% in 24 hours of hydraulic
retention time.
4.5 Chapter V
Experiments were conducted using artificial and
synthetic filter media as material. Nylon threads and
plastic ball were used in the present study. Nylon threads
were made up of poly amides which are thermo plastic
299
and silky in nature. Nylons are condensed
copolymers formed by reacting equal parts of
a diamine and a dicarboxylic acid, so that amides are
formed at both ends of each monomer in a process
analogous to polypeptide biopolymers. Plastic balls were
made up of poly propylene which is a thermo plastic and
light weight in nature.
Nylon material thread as biofilter
Nylon threads of 0.1 cm radius and 28 cm length
of equal sized threads were used for the present study
(Image 9, page 508). Volume of the nylon thread was
calculated using formula V = πr2h, and it was observed
that each thread had a volume of 0.88 cm3. Based on the
volume of the reactor, various volumes of nylon threads
i.e., 5687 pieces (10% of working volume), 11374 pieces
300
(20% of volume), 17061pieces (30% of volume) and
22748 pieces (40% of volume) were used in the present
study. Surface area of the nylon thread was determined
and it was 17.65 cm2 for each nylon thread. The specific
surface area of nylon thread was determined by dividing
the surface area with volume of the nylon thread and
converted to meter scale and it was 2007.14 m2/m
3.
4.5.1. Effect of various volumes of nylon threads as
biofilter material along with 0.2% consortium
and 12 hours HRT
The results for the treatment of domestic
wastewater treatment with 0.2% consortium and 12
hours HRT and nylon threads as biofilter material a
decrease in BOD by 67.42% in presence of 10% volume.
70.41% of BOD was reduced with 20% volume, 75.19%
in the presence of 30% volume and 75.79% with 40%
301
volume of material. Results of various other parameters
are tabulated (Table 58 – 59, page 472 & 473). After the
completion of experiments with various volumes of
nylon threads as biofilter material, it was noted that there
was a significant variation in the removal efficiency of
pollutant. The results were observed to be useful for
sewage treatment process. Graph was drawn and
represented in fig 18, page 527. Further experimentation
was continued by using 30% of nylon threads as
optimized volume of biofilter material, 0.2% inoculum at
various HRT’s like 8 hours, 9 hours, 10 hours, 11 hours
and 12 hours to determine the effect of hydraulic
retention time in the presence of nylon threads as
biofilter material.
302
4.5.2 Effect of various HRT’s in the presence of 30%
volume of nylon threads as biofilter
material, 0.2% inoculum
The maximum removal efficiency of BOD was
obtained after 9 hours of HRT. The treatment of
wastewater by the addition of 0.2% inoculum and 30%
volume of nylon threads as biofilter material for various
HRT’s revealed the reduction of BOD by 67.06% for 8
hours of HRT, 74.9% for 9 hours HRT, 76.74% for 10
hours HRT, 77% for 11 hours of HRT and 80.47% for
12 hours of HRT. Results of other parameters are
tabulated (Tables 60 – 62, page 474 - 476). After
completion of experimentation with 30% volume of
nylon threads as biofilter material, 0.2 % inoculum at
various HRTs, it was noted that 9 hours HRT showed
significant changes during the treatment process. Hence,
9 hours HRT was considered as optimized HRT (fig 19,
303
page 528). Further experimentation was conducted to
determine the viability and increase of performance of
filter material. Experiments were conducted for 60 days
and samples of wastewater before and after treatment
were analyzed for every 10 day interval.
4.5.3 Time period
The maximum removal efficiency of BOD was
obtained up to 60 days of time period. The results of
removal efficiency of BOD at different time periods are
tabulated. Effect of time period on 30% volume of nylon
threads as biofilter material along with 0.2% consortium
as inoculum & 9 hours HRT for domestic wastewater
treatment in terms of BOD removal revealed the
reduction of BOD by 81.48% for 10 days time period,
82.07% for 20 days time period, 83.14% for 30 days
304
time period, 84.24% for 40 days time period, 84.75% for
50 days time period and 85.19% for 60 days time period.
Results of various other physico-chemical parameters are
tabulated (Table 63 – 65, page 477 - 479). After
completion of experimentation with 30% volume of
nylon threads as biofilter material, 0.2 % inoculum and 9
hours HRT at various time periods, it was noted that the
efficiency removal of BOD and other pollutants were
increased up to 60 days of operation (fig 20, page 529).
Hence, 60 days of time period can be considered as
optimized time period for the treatment process of
domestic wastewater.
Plastic ball as biofilter material
Experiments were conducted using artificial and
synthetic filter media as material. Plastic balls 1.8 cm
305
radius of equal sized sphere shaped balls were used for
the present study (Image 10, page 509). Volume of the
plastic ball was calculated using formula V = 4/3πr3, and
it was observed that each plastic ball had a volume of
24.42 cm3. Based on the volume of the reactor, various
volumes of plastic balls i.e., 205 pieces (10% of working
volume), 410 pieces (20% of volume), 614 pieces (30%
of volume) and 819 pieces (40% of volume) were used
in the present study. Surface area of the plastic ball was
determined and it was 40.69 cm2 for each plastic ball.
The specific surface area of plastic ball was determined
by dividing the surface area with volume of the plastic
ball and converted to meter scale and it was 166.67
m2/m
3.
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4.5.4 Effect of various volumes of plastic balls as
biofilter material along with 0.2% consortium
and 12 hours HRT
The results of various volumes of plastic balls as
biofilter material along with 0.2% consortium and 12
hours HRT for the treatment of domestic wastewater
treatment revealed that a decrease in the BOD by
60.84% in the presence of 10 % volume of plastic balls.
60.54% of BOD was removed in the presence of 20%
volume of filter material, 60.95% with 30% filter and
60.77% in the presence of 40% filter material. Results of
various other physico – chemical parameters are
tabulated (Table 66 – 67, page 480 & 481). After the
completion of experiments with various volumes of
plastic balls as biofilter material, it was noticed that there
was no significant variation in the removal efficiency of
pollutant. The results were similar to that of experiments
307
without filter material as represented in fig 21, page
530). Further experimentation was continued by using
10% of plastic balls as optimized volume of biofilter
material, 0.2% inoculum at various HRT’s like 8 hours,
9 hours, 10 hours, 11 hours and 12 hours to determine
the effect of HRT in the presence of plastic balls as
biofilter material.
4.5.5 Effect of various HRT’s in the presence of 10%
volume of plastic balls as biofilter material,
0.2% inoculum
The maximum removal efficiency of BOD was
obtained after 12 hours of HRT. The treatment of
wastewater by the addition of 0.2% inoculum and 10%
volume of plastic balls as biofilter material for various
HRT’s revealed the reduction of BOD by 46.7% for 8
hours of HRT, 48.82% for 9 hours HRT, 51.11% for 10
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hours HRT, 54.08% for 11 hours of HRT and 60.99%
for 12 hours of HRT. Various other parameter results are
tabulated (Table 68 – 70, page 482 - 484). After
completion of experimentation with 10% volume of
plastic balls as biofilter material, 0.2 % inoculum at
various HRTs, it was noted that 12 hours HRT showed
significant changes during the treatment process, and
results were more or less similar when compared with
the treatment process without filter material. Hence, 12
hours HRT was considered as optimized HRT as
represented in fig 22 (page, 531). Further
experimentation was conducted to determine the
viability and increase of performance of filter material.
Experiments were conducted for 60 days and samples of
wastewater before and after treatment were analyzed for
every 10 day interval.
309
4.5.6 Time period
The maximum removal efficiency of BOD was
not obtained during 60 days of time period. Effect of
time period on 10% volume of plastic balls as biofilter
material along with 0.2% consortium as inoculum & 12
hours HRT for domestic wastewater treatment in terms
of BOD removal revealed that the reduction of BOD
occurred by 60.02% for 10 days time period, 60.59% for
20 days time period, 61.23% for 30 days time period,
62.24% for 40 days time period, 59.57% for 50 days
time period and 61.07% for 60 days time period. Results
of various other physico-chemical parameters are
tabulated (Tables 71-73, page 485 - 487). After
completion of experimentation with 10% volume of
plastic balls as biofilter material, 0.2 % inoculum and 12
hours HRT at various time periods, the efficiency
310
removal of BOD and other pollutants were not
significant during the 60 days of operation (fig 23, page
532).
Savage and Tyrrel (2005), reported variations in
the removal percentages of pollutants for various types
of materials as biofilter media viz., polystyrene packing
material, wood mulch. They reported that BOD removal
efficiency by polystyrene material is 34% and
ammonical removal efficiency is 31% from the compost
litter waste. They further reported that 70% BOD
removal efficiency and 75% removal of ammonical
nitrogen can be achieved with wood mulch as biofilter
material. Amit et al. (2003), achieved 11 times more
removal efficiency of ammonical nitrogen concentration
when compared to control experiment. They
311
demonstrated nitrifying biofilter using plastic beads
(macaroni) and achieved the control of ammonical
concentration in the lab scale experiment. They isolated
microorganisms from local soil and obtained good
results by controlling the less than 2mg/litre. Anthony et
al. (1998), compared the polystyrene beads with
polyethylene packing material and reported that
polystyrene micro beads removes 3.2 times more
ammonical nitrogen per day/ unit volume of reactor.
In support of our observation, Andreottola et al.
(2000), reported 76% of COD removal efficiency in
moving bed biofilm reactor and 84% in activated sludge
reactor using plastic media of volume 70% with specific
surface area 160m2/m
3 for HRT 6.7 – 14hours. They also
obtained 92% ammonical nitrogen removal efficiency
312
using the same characteristics of biofilter media. Valsa
Ramony Manoj and Namasivayam Vasudevan (2012),
used coconut coir and Fujino spirals as biofilter materials
for the removal of nutrients in biological treatment of
aqua culture waste water and reported that average
removal percentage of nitrate nitrogen were 86% for
coconut coir and 80% for fujino spirals and the average
phosphorus removal rates were 49 and 47% for coconut
coir and fujino spirals respectively. According to them
the removal % of pollutants was more for organic filter
materials when compared to synthetic materials.
Jechalke et al. (2010), studied biofilm
development on coconut fibers and polypropylene
textiles for enhancing biodegradation of low
concentration methyl tert-butyl ether (MTBE), benzene
and ammonium from groundwater in aerated treatment
313
ponds. Coconut fibers were more effective biofilm
support media than polypropylene textiles for
recruitment and development of biofilms for MTBE
degradation. It envisages that biogenic materials are
more favorable for the formation of biofilms and helpful
in elimination of pollutants.
4.6 Chapter VI
4.6.1 Process of treatment using optimized conditions
Experiments were conducted using optimized
conditions for parameters viz., volume, HRT and time
period for each biofilter material and compared their
removal efficiencies and changes during the processes of
treatment. The optimization of the various parameters in
the treatment process considerably enhanced the
pollutant removal efficiency. All results were tabulated,
314
graphs were plotted and results are discussed for each
parameter.
4.6.1.1 pH
pH decreased during the treatment process, when
stone was used as biofilter media. It was observed that
0.1unit was decreased in the treatment process followed
by wood chip, nylon thread and plastic ball. Using the
above filter media pH was decreased by 0.1unit, pH was
increased by 0.1unit in the presence of clay ball as filter
media. pH had no change during the process of treatment
when sintered glass cylinder and corn cobs were used
(Tables 74 – 80 pages 488 - 494; Fig. 24, page 533).
Biological metabolism is strongly dependent on pH.
Many microorganisms will only grow within a particular
pH range. Michael et al. (1999), reported that the usual
315
pH range for pollutant removal through biofilters is 6.0 –
8.0. Vaiškunait (2008) reported that hydrogen ion
concentration plays a significant role in the growth and
the reproduction of microorganisms in biofiltration
process. In the work of the scientist Aizpuru (2003), it
was determined, that the biodegradation is significantly
increased when the waste was saturated with water and
the pH adjusted above 6.5. Akao and Tsuno (2007),
reported that activities of the microorganisms inside the
biofilter will decrease if pH value is too low. In the
present study, the pH of sewage ranged from 7.0 – 8.2
before and after treatment. There was no significant
variation in pH range while using various filter
materials. Furthermore, the pH range was more suitable
for microorganisms used in the present study.
316
4.6.1.2 Electric conductivity
In the present study, decrease of electric
conductivity ranged from 12.09% - 22.22% during
treatment process using optimized conditions. The order
of electric conductivity removal by biofilter media was
more in treatment process using nylon threads as
biofilter media (decreased by 22.22%) and followed by
woodchips (diminished by 22.07%), corn cobs (reduced
by 22.21%), clay balls (minified by 20.04%), sintered
glass cylinders (lessened by 19.9%), stones (decreased
by 18.93%) and plastic balls (minimized by 12.09%).
Results are tabulated, (Tables 74 -80; Fig. 25, page 534).
Levlin (2007), reported a reduction of 21 – 28% of
electric conductivity during the treatment process using
activated sludge at Stockholm wastewater treatment
plant. In the present study, electric conductivity was
317
reduced from 12 – 22 % using various kinds of filter
media along with consortium.
4.6.1.3 Temperature
Temperature has no significant change during the
process of treatment. It neither increased nor decreased
in the treatment process. The organisms used in the
present study were mesophilic in nature and ambient
temperature was used in the experiment. Hence, this
might be the reason for the absence of variations in the
treatment process for minimal temperature changes
(Tables 74 – 80, page 488 - 494). According to Michael
et al. (1999), the optimal temperature range for
biofiltration process is 20°C - 40°C. Miao et al. (2005),
obtained best results in the temperature range of 25 -
35°C for rapeseed oil smoke removal with the 95%
318
removal efficiency. Von Bernuth et al. (1999) reported
that mesophilic bacteria are of most importance for
agricultural biofilters because they prefer temperatures
between 10 and 50°C. Fontenot et al. (2007), reported
that the temperature range of 22–37 °C gave best results
in terms of maximum nitrogen and carbon removal from
a shrimp aquaculture wastewater, but denitrification
processes will normally occur in the range 2–50 °C
(Brady and Weil, 2002) and possibly beyond, where
bacteria have evolved to cope with specific
environmental conditions. Various reports show that
high temperature of 28–38°C is favorable for nitrogen
removal via nitrite due to the fact that the specific
growth rate of AOB is higher than that of NOB
(Brouwer et al. 1996). In the present study, the
temperature ranges during operation of various
319
experiments ranged from 24 -28°C and was the most
suitable temperature for mesophilic organisms which
were used in the study. Similarly, the temperature had
not shown any effect and variation on type of biofilter
material.
4.6.1.4 Total suspended solids
In the present study, the removal efficiency of
TSS ranged from 59.12%-83.05% during treatment
process using optimized conditions. Total suspended
solids removal efficiency was observed to be more in the
treatment process using corn cobs as the biofilter media.
This value was followed by values of wood chips, nylon
thread, clay ball, sintered glass cylinder, plastic ball and
stone. The removal efficiency of total suspended solids
by stone as biofilter media was 59.12%, clay ball
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71.96%, sintered glass cylinder 71.95%, corn cobs
83.05%, wood chips 82.53%, nylon thread 81.16% and
plastic ball 51.91%. Results are tabulated (Tables 74 –
80, Fig. 26, page 535). Ahmad (2010), reported the
removal efficiency of total suspended solids ranging
from 96 – 97% during the tertiary treatment of
wastewater. According to Al-Turki (2010), the reduction
of SS in filtering mass varied between 48 and 96%.
4.6.1.5 Volatile suspended solids
In the present study, VSS removal efficiency
ranged from 50.45%-71.97% during treatment process
using optimized conditions. Volatile suspended solids
decreased by 51.3% using stone as filter media, 59.15%
in the presence of clay balls, 59.18% in the presence of
sintered glass cylinders, 69.44% in the presence of corn
321
cobs, 67.82% in the presence of wood chips, 71.97% in
the presence of nylon threads and 50.45% in the
presence of plastic balls. The order of volatile suspended
solids removal efficiency by biofilter media was nylon
threads followed by corn cobs, wood chips, sintered
glass cylinders, clay balls, stones and plastic balls
(Tables 74 – 80; Fig. 27, page 536). Pongsak et al.
(2009), reported the removal efficiency of volatile
suspended solids as 72.8% by comparing 5 centralized
sewage treatment plants in Bangkok. In the present study
it was achieved in the treatment process using nylon
threads as filter material.
4.6.1.6 Chlorides
In the present study, the removal efficiency of
chlorides ranged from 53.97% - 73.06% during
322
treatment process using optimized conditions. Chloride
removal efficiency was more in the treatment process
using nylon threads as the biofilter media. It was
followed by corn cobs, clay balls, sintered glass
cylinders, wood chips, stones and plastic balls. The
removal efficiency of chlorides by stones as biofilter
media was 54.46%, clay ball 72.04%, sintered glass
cylinder 70.24%, corn cobs 72.22%, wood chips 68.9%,
nylon thread 73.06% and plastic ball 53.97%. Results
were tabulated (Tables 74 – 80; Fig. 28, page 537). Ali
et al. (2006), reported a reduction of 49.59 – 59.82% of
chloride, when ferric chloride was used as coagulant for
treatment of textile wastewater. According to Kumar
(1989) and Lalvo et al., (2000), chloride content can
serve as a pollutant indicator in wastewater, when
considered together with other parameters and high
323
chloride content in wastewater may harm for agricultural
crops, if it is used for irrigation purpose.
4.6.1.7 Hardness
In the present study, the removal of hardness
ranged from 31.08% - 66.11% during treatment process
using optimized conditions. Hardness decreased by
31.95% using stone as filter media, 49.52% of BOD was
reduced with clay balls, 50.94% of BOD minified with
sintered glass cylinders, 66.02% of BOD lessened with
corn cobs, 64.04% of BOD diminished with wood chips,
66.11% of BOD decreased with nylon threads and
31.08% of BOD reduced in the presence of plastic balls.
The order of hardness removal efficiency by biofilter
media was nylon threads followed by corn cobs, wood
chips, sintered glass cylinders, clay balls, stones and
324
plastic balls (Tables 74 – 80; Fig. 29, page 538).
Ali et al. (2006), obtained a reduction of
33.33 – 73.69% of hardness during treatment process of
textile wastewater using ferric chloride as coagulant.
4.6.1.8 Alkalinity
In the present study, the reduction of alkalinity
ranged from 40.98% - 67.02% during treatment process
using optimized conditions. Alkalinity reduced during
the treatment process by 40.98% using stones as biofilter
media, 56.57% using clay balls as biofilter media,
57.05% using sintered glass cylinder as biofilter media,
66.94% using corn cobs as biofilter media, 66.05% using
wood chips as biofilter media, 67.02% using nylon
threads as biofilter media and 41.08% using plastic balls
as biofilter media. The order of removal efficiency of
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alkalinity by various biofilter media were nylon threads
followed by corn cobs, wood chips, sintered glass
cylinders, clay balls, plastic balls and stones (Tables 74 -
80; Fig. 30, page 539). Boon et al. (1997), used biofilter
for the treatment of high strength wastewater and
obtained 58.33% alkalinity removal.
4.6.1.9 Chemical oxygen demand (COD)
The removal efficiency of chemical oxygen
demand during the treatment process was more for corn
cobs using as biofilter media and the removal efficiency
was 82.48%. It was followed by wood chips and COD
decreased by 82.44%. Nylon threads as biofilter media
removed 81.88% of COD during the treatment process.
The removal efficiency of COD by clay balls was
72.82% and it was followed by sintered glass cylinders
326
by removing the COD by 71.87%. Stones as biofilter
media removed 64.05% of COD and it was followed by
plastic balls with the removal efficiency of 62.97%.
Results are furnished in the tables (Tables 74 - 80; Fig.
31, page 540).
Claudio et al. (2005), evaluated the performance
of periodic biofilter for treating municipal wastewater.
They obtained good results with the C.O.D concentration
of effluents was lower than 60mg/litre, 90 – 95% of
kjeldhal nitrogen removal by extensive denitrification
and high removal rate of suspended solids about 90%
and a negligible sludge production. Moosavi et al.
(2005), investigated the COD removal for high strength
organic wastewater in this reactor and found COD
removal efficiency to be about 95% under organic
327
loading of 0.8-7.6 kg CODm-3
/day. Pozo and Diez
(2003), studied the COD removal for organic matter
containing wastewater in aerobic-anaerobic packed bed
reactor and they found the efficiency to be 92% at
organic loading of 0.39 kg COD m-3day-1. Florante et
al. (2009), obtained 98% reduction in COD in aerobic
reactor, as supported by increasing concentration of
MLVS, with a hydraulic retention time (HRT) of 5 hours
after 11 days while 34% reduction in COD was obtained
in anaerobic reactor with the same HRT after 14 days. In
the present study, COD reduction ranged from 62-82%.
It is envisaged that filter materials are suitable for
removal of COD.
4.6.1.10 Biochemical oxygen demand (BOD)
Biochemical oxygen demand reduction during
the treatment process was 85.04% using corn cobs as
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biofilter media. It was followed by nylon threads, wood
chips, sintered glass cylinders, clay balls, stones and
plastic balls. The biochemical oxygen demand removal
efficiency by stones as biofilter media was 61.29%,
73.02% using clay balls as biofilter media, 73.06% using
sintered glass cylinder as biofilter media, 83.53% using
wood chips as biofilter media, 85% using nylon threads
as biofilter media and 60.07% using plastic balls as
biofilter media. Results are tabulated (Tables 74 - 80;
Fig. 32, page 541). Nadirah et al. (2008), applied the
bioparticle onto biofilter system as a filtering media to
treat domestic wastewater and obtained results with the
removal efficiencies of BOD 61%, COD 97%,
ammonical nitrogen 86%, suspended solids 71%, oil &
grease 53%, nitrate 50%. Dempsey et al. (2005),
reported that 56 – 62% removal of BOD and suspended
329
solids can be achieved using glassy coke as the support
biofilter material. Nikolaus kaindl (2010), used moving
bed biofilm reactor (MBBR) for upgrading of an
activated sludge wastewater treatment plant of paper mill
effluent and achieved 98% reduction in BOD and 82%
reduction in COD along with pre-treatment and
ozonation.
4.6.1.11 Total nitrogen
The removal efficiency of total nitrogen by
stones as biofilter media was observed as 47.84%; in the
presence of clay balls the removal efficiency was
62.53%; in the presence of sintered glass cylinders as
biofilter media the removal efficiency of total nitrogen
62.69%; in the presence of corn cobs the total nitrogen
removal efficiency was 70.23%; with wood chips total
330
nitrogen reduced by 68.48%; with nylon threads the
removal efficiency was observed as 71.72% and in the
presence of plastic balls the removal efficiency was
46.47%. The removal efficiency of total nitrogen was
more in the presence of nylon thread when compared to
other filter media and it was followed by corn cobs,
wood chips, sintered glass cylinders, clay balls, stones
and plastic balls. Results are furnished in tables 74 – 80
and Fig. 33, page 542).
Ammonical nitrogen
The removal efficiency of ammonical nitrogen by
corn cobs as biofilter media was 73.19% and it was
followed by nylon threads (72.85%), wood chips
(71.05%), sintered glass cylinders (65.03%), clay balls
(64.85%), stones (50.1%) and plastic balls (48.03%).
331
Results are presented in tables 74 – 80 and Fig. 34, page
543)
Nitrite nitrogen
The concentration of nitrite nitrogen was
increased during the treatment process and it was more
in the presence of nylon threads with 400% increase
followed by corn cobs with 300% rise. The nitrite
nitrogen was enhanced by 200% with wood chips &
sintered glass cylinders, and followed by 133.33% with
clay balls. In the presence of stones, the nitrite nitrogen
was raised by 73.33% and 40% with plastic balls. The
increase of nitrite concentration during the process of
treatment might be due to the transformation of
332
ammonical nitrogen. Results are presented in tables 74 –
80 and Fig. 35, page 544).
Nitrate nitrogen
The nitrate nitrogen concentration was also
increased during the process of treatment and it was the
greatest in the presence of stones as biofilter media and
the increase was by 55.56%. this was followed by nylon
threads (50%), sintered glass cylinders (39.39%), corn
cobs (36.11%), clay balls (30.56%), plastic balls
(27.27%) and wood chips (22.22%). Results are
furnished in tables 74 – 80 and Fig. 36, page 545.
Kjeldhal nitrogen
Kjeldhal nitrogen removal efficiency was more in
the treatment process using nylon threads as the biofilter
333
media. It was followed by corn cobs, wood chips, clay
balls, sintered glass cylinders, stones and plastic balls.
Kjeldhal nitrogen removal efficiency by stones as
biofilter media was 50%, clay balls 67.35%, sintered
glass cylinders 66.34%, corn cobs 73.68%, wood chips
71.28%, nylon threads 73.74% and plastic balls 50%.
Results are presented in tables 74 – 80 and Fig. 37, page
546).
Pongsak et al. (2009), reported that the biological
nitrogen removal in a wastewater treatment plant ranged
from 14.9 - 56.3% during the process of treatment at
centralized systems in Bangkok. In the present study, the
removal of total nitrogen ranged from 46-72%. It
envisages that the microbes present in the consortium
might be useful for the removal of pollutants. According
to Asma et al. (2011), the nitrification efficiency is
334
represented by high levels of nitrate (NO3 --N) in treated
wastewater. Nitrogen removal is independent of
infiltration depth whereas NO3 –N concentrations
increased with depth. This effectiveness is maintained
when conditions are favorable: no clogging, neutral pH
to slightly alkaline and temperature ranged between 30
and 35°C. Koottatep (2004) reported that organic
nitrogen is mineralized to ammonia by hydrolysis and
bacterial degradation. Nitrates are then converted to
nitrogen gas (N2) and nitrous oxide (N2O) by
denitrifying bacteria in anoxic and anaerobic zones
which usually occur in limited oxygen supply. The major
portions of nitrogen compounds in municipal wastewater
are reduced nitrogen compounds such as ammonia, urea,
amines, amino acids, and proteins. The main organic
nitrogen compounds in municipal wastewater are
335
heterocyclic compounds e.g. nucleic acids and proteins.
Proteolysis and degradation of amino acids leads to
liberation of ammonia by the various mechanisms of
ammonification (Rheinheimer et al., 1988), including
hydrolytic, oxidative, reductive and desaturative
deamination. Bernet et al. (1996), estimated that bacteria
consist of roughly 50% protein and that the nitrogen
content of protein is about 16%. Thus, for synthesis of 1
g of bacterial biomass, about 0.08 g of ammonia-N is
required. Autotrophic nitrifiers are aerobic
microorganisms oxidizing ammonia via nitrite to nitrate.
Organisms catalyzing nitrification belong to the
genera Nitrosomonas, Nitrosococcus, Nitrosolobus,
Nitrosospira and Nitrosovibrio. Organisms catalyzing
nitration include members of the genera Nitrobacter,
336
Nitrococcus, and Nitrospira. George et al. (2001),
reported that chemolitho-autotrophic ammonia-oxidizing
bacteria are responsible for the rate limiting step of
nitrification in a wide variety of environments, making
them important in the global cycling of nitrogen. These
organisms are unique in their ability to use the
conversion of ammonia to nitrite as their sole energy
source. Foglar et al., (2005), reported that nitrate is a
common water contaminant that can cause health
problems in humans. Also, eutrophication or ground
water contaminations by nitrate, which cause serious
social and economical problems, are related to an
increase of nitrate concentration in the aquatic
environment. According to Balmelle et al., (1992), Yang
and Alleman, (1992) and Hao and Chen, (1994), when
nitrogen loading increases beyond a certain level, partial
337
nitrification may occur in the biological process under
aerobic condition. The partial nitrification can result into
nitrite build up in the biological process. Due to its
toxicity, nitrite build up can inhibit the microbial
phosphorus uptake in the biofilter under aerobic
condition. This nitrite build up can have a deleterious
influence on microbial phosphorus release as well as
microbial phosphorus uptake in this system (Ghekiere et
al., 1991).
Oh et al. (2001), evaluated the feasibility of the
treatment of concentrated nitrate wastewater with a
submerged biofilter, and found that the performance of
the submerged biofilter was satisfactory in treating
concentrated nitrate optimally within a limited space,
provided biofilter loading was less than 9 kg NO3–
338
N/m3/d. Instead of nitrate, many denitrifying bacteria can
use NO2–, NO, or N2O as terminal electron acceptors.
Alternatively, they may release these intermediates
during denitrification of nitrate under unfavorable
conditions as was observed in soil (Conrad, 1996). If
surplus nitrate is supplied and hydrogen donors are not
sufficiently available, NO and N2O can be formed
(Schön et al., 1994). Another condition for N2O
formation is a pH below 7.3, at which nitrogen
oxidoreductase is inhibited (Knowles, 1982).
Autotrophic ammonia oxidizers seem to be able
to produce NO, N2O, or N2 from nitrite if oxygen is
limited and ammonia as well as nitrite oxidizers can be
isolated from anaerobic reactors (Kuenen and Robertson,
1994). Nitrosomonas europaea can use nitrite as an
339
electron acceptor and pyruvate as an energy source under
anoxic, denitrifying growth conditions (Abeliovich and
Vonshak, 1992). In addition, several strains of
Nitrobacter sp. were reported to denitrify during anoxic,
heterotrophic growth (Bock et al., 1986). It is believed
that the role of Nitrobacter and Nitrosomonas sps is very
critical for the transformation of nitrogen to various
other forms and its removal. In the present study, the
concentration of both the organisms were also increased
in its consortium.
4.6.1.12 Total phosphorus
Phosphorus concentration was reduced during the
process of treatment by 52.88% using stones as biofilter
media, 67.65% applying clay balls as biofilter media,
67.3% with sintered glass cylinder as biofilter media,
340
74.51% employing corn cobs as biofilter media, 72.73%
utilizing wood chips as biofilter media, 74.07% with
nylon threads as biofilter media and 52.13% using
plastic balls as biofilter media. The order of removal
efficiency of phosphorus by various biofilter media were
corn cobs followed by nylon threads, wood chips, clay
balls, sintered glass cylinders, stones and plastic balls.
Results are tabulated (Tables 74 - 80; Fig. 38, page 547).
Henze (1996) and Metcalf and Eddy (1991)
report values of 10-25% for phosphorus removal during
secondary treatment of municipal wastewater. Sotirakou
et al. (1999), achieved 15% removal of total phosphorus
with extended aeration process in the municipal
wastewater treatment plant. In the present study,
341
utilization of external source of phosphate solubulizing
microbes resulted in achieving positive results.
4.6.1.13 Oil and grease
The order of oil and grease removal by biofilter
media was more in the treatment process using corn
cobs biofilter media (decreased by 6.25%) followed by
woodchips (decreased by 5.56%), nylon threads
(decreased by 4.9%), clay balls (decreased by 3.51%),
sintered glass cylinders (decreased by 3.13%), stones
(decreased by 2.94) and plastic balls (decreased by
0.93%). Results are tabulated (Tables 74 - 80; Fig. 39,
page 548). According to Young (1979), oils are
generally believed to be biodegradable and therefore
considered as part of the organic load that is treated.
However, oils have detrimental effects on oxygen
342
transfer In aerobic wastewater treatment systems. They
reduce the rates at which oxygen is transferred to
biofilms, thereby depriving the microorganisms of
oxygen (Chao and Yang, 1981). Young (1979), reported
that oxygen demand of influent dispersed polar oil
should be considered as part of the normal BOD load to
the treatment plant so that effluent BOD measurements
would include the oxygen demand of biodegradable oil
in the effluent samples.
Various microorganisms have the ability to
produce extra-cellular lipases that hydrolyse
triglycerides to fatty acids and glycerol (Wakelin and
Forster, 1997; Paparaskevas et al., 1992; Ratledge,
1992). Examples are the bacteria Pseudomonas
fluorescens, Chromobacterium vinosum and the fungi
343
Aspergillus niger and Rhizopus delemar (Tuter et al.,
1998). Oils in this case are used as substrates for
microbial growth, resulting in an increase in the
concentration of microorganisms in the treatment
system. Keenan and Sabelnikov (2000), studied the
biodegradation of corn, olive, sunflower and waste oils
by a variety of bacterial strains such as Acinetobacter
sps., Rhodococcus sps. and Caseobacter sp. that were
isolated from different environments based on their
ability to grow on vegetable and waste oils and by
commercial bacterial preparations specifically designed
for oil degradation.
In the present study, the microorganisms used for
bioremediation of sewage did not show any significant
removal efficiency of oil and grease. As per literature,
344
the microbial consortium required for oil and grease
degradation varied from the consortium used in the
present study. This might be one reason why there is no
significant change in the removal efficiency of oil and
grease.
4.6.1.14 Hydrogen sulphide
The removal efficiency of hydrogen sulphide
during the treatment process was more for corn cobs
when used as biofilter media and the removal efficiency
was 75.86%. It was followed by wood chips when the
hydrogen sulphide decreased by 71.43% and stones
when it decreased by 67.86%. Nylon threads, sintered
glass cylinders, clay balls were found to be similar in the
removal efficiency and it was 66.07%. Plastic balls
removed 53.57% during the treatment process. Results
345
are presented in tables 74 - 80; Fig. 40, page 549.
Rene et al. (2008), reported that 90% removal efficiency
was achieved using artificial neural networks (ANN)
biofilters to remove hydrogen sulphide vapors.
Hydrogen sulphide (H2S) is used extensively as a
digesting agent in the pulp and paper industry. However,
the potential large emitters of hydrogen sulphide
includes electric power plants (burning coal or fuel oil
containing sulfur), oil and gas extraction operations, oil
refineries, pulp and paper mills, sewage treatment plants,
large pig farms, confined animal feeding operations and
aerobic composting of low C:N material.
Hydrogen sulfide is commonly found in coal and
petroleum deposits and may be mobilized by human
manipulation of these resources. Most hydrogen sulphide
releases are directly to the ambient atmosphere.
346
Inhalation is the major route of exposure to hydrogen
sulfide in the environment. Hydrogen sulfide is
disruptive to the mitochondrial electron transport system
and is thus expected to affect all systems. According to
Kuenen and Robertson (1992), a lower concentrations of
H2S results in depression (0.12 mg per m3),
conjunctivitis and visual problems (1.5 - 43 mg per m3)
and psychic changes, dizziness and vomiting (70 – 700
mg per m3) in humans. In the present study, the
concentration of H2S in untreated domestic wastewater is
ranged from 2.5 – 3.0 mg/lit. After treatment by
microbial consortium and various filter materials the
concentration of H2S decreased to 0.8-1.2 mg/lit.
4.6.1.15 Sludge volume index
The removal efficiency of sludge volume index
by stones as biofilter media was observed as 37.1%, in
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the presence of clay balls the removal efficiency was
36.36%, in the presence of sintered glass cylinders as
biofilter media the removal efficiency was 35%, with
corn cobs removal efficiency was 55.71%, for wood
chips the removal efficiency was 49.23%, with nylon
threads the removal efficiency was observed as 53.13%
and in the presence of plastic balls the removal
efficiency was 47.69%. The removal efficiency of sludge
volume index was more in the presence of corn cobs and
nylon threads when compared to other filter media and it
was followed by woodchips, plastic balls, granite stones,
clay balls and sintered glass cylinders, (Tables 74 - 80;
Fig. 41, page 550). Kwannate et al. (2011), reported 40
to 60 ml/g of SS in the effluent of treated piggery
wastewater. SVI is an important parameter affecting the
performance of a wastewater treatment system. Low SVI
348
values (<100 ml/g of TSS) indicate good sedimentation
characteristics of the sludge yielding high biomass
concentrations in the aeration tank, whereas high SVI
values (>100 ml/g) reflect bulky sludge and low biomass
concentrations in the aeration tank (Kargi and Uygur,
2002). In the present study, the SVI ranged from 60-80
ml/g SS after the treatment process using various filter
materials and shows good settling properties which will
be useful for proper treatment of sewage.
4.6.2. Comparative analysis of filter media
4.6.2.1 Volume of filter media
The effect of biofilter media for the pollutant
removal efficiency not only depends upon their
elimination capacity but also on their economics. In the
current perspective, less volume of filter media, low
349
hydraulic retention time and the effect (in terms of
elimination efficiency of pollutants) for more time
period are set to be useful in economic point of view. To
evaluate this scenario, graphical illustration was made
for all the filter materials in terms of volume %,
hydraulic retention time in hours and time period in
days. As per the previous reports, it was found that 12 –
70% volume range of filter media were used for
biofiltration process. In the present study, an attempt was
made to use low quantity of filter media for effective
removal of pollutants. In this concern, 10%, 20%, 30%
and 40% volume of various filter media were used for
experimentation. Reduction of BOD was considered for
graphical representation to compare filter media and are
represented in fig 42, page 551. Out of 7 filter media,
corn cob showed more elimination capacity of
350
biochemical oxygen demand (74.9%) with 20% volume
and it was followed by 30% volume of nylon thread,
30% volume of wood chip, 30% volume of sintered glass
cylinder, 30% volume of clay ball, 10% volume of
plastic ball and 10% volume of stone.
Major constrains in the use of treated sewage are
related to the undefined and sometimes even hazardous
composition of the waste stream (including its
fluctuations) and the uncertainty at the user’s side that
the applied technology cannot adequately handle all
contaminants. Therefore, instead of the end-of-the-pipe
approach one could also choose to work upfront,
identifying the compounds that are limiting reuse. If
industries are forced to treat their own wastewater and
are excluded from the sewage network, than the
351
concentrations of micro pollutants, heavy metals,
xenobiotics, etc., will drop to a negligible level.
Considering the fact that decentralized systems are
merely treating effluents of domestic origin, it is much
easier to link decentralized sewage treatment to reuse
than the large scale applications. Moreover, the latter
ones require large infrastructural investments both at the
collection site and the distribution site and are therefore
more difficult to realize on the short term. Obviously this
particularly applies for those areas that, so far are not
connected to large sewerage networks (Lier et al., 2002).
Choosing appropriate filter material is a major constrain
in biofiltration process. The nature, applicability,
characteristics, type, availability and cost a the few
important parameters that are to be considered before
choosing a filter material. Biofilter is a material either
352
biogenic or abiogenic in nature, which facilitates the
formation of biofilm. The nature of the biofilter material
i.e., smooth texture or rough texture plays an important
role in the formation of biofilm onto the material.
In the present study, out of 7 filter materials
granite chips, nylon threads and plastic balls are smooth
surfaced objects and the remaining viz. clay balls,
sintered glass cylinders, corn cobs and wood chips are
rough textured objects. Except nylon threads, both
granite chip and plastic ball objects show primitive
results when compared to other objects. The surface area
of nylon thread used in the study is much more and that
might be the reason for promising results. The nature of
the filter materials also plays an important role in
treatment of pollutants. In the present study, corn cobs
353
and wood chips are biogenic in nature and the remaining
objects are non-biogenic in nature. The removal of
pollutants was more for biogenic filter materials when
compared to non-biogenic filter materials except for
nylon threads. The applicability of the filter material i.e.,
its size, shape and abundance plays a vital role in
selecting the material. in the present study, various sizes
and shapes of filter materials were used. Granite chip is a
square cuboid, clay balls and plastic balls are spheroid,
sintered glass cylinder and nylon threads are solid
cylindrical shape and corn cob is a hollow cylindrical
shaped structure with high crevices on the outer surface.
The removal efficiency of pollutants was more for corn
cobs and least for granite chips and plastic balls.
354
According to Leopoldo and Tom (1999), the
shape of the media also has an effect on reactor
performance. Irregular shapes have been found to
improve performance of biological aerated filters
compared to spherically shaped media, through variation
in the size of the void spaces. The roughness of the
media also has an effect on the performance of the
reactor. Rough space media provides more sites for
biofilm attachment than smooth media. According to
Leopoldo and Tom (1999), smooth media restricts
biofilm growth as microorganisms are unable to attach
properly to the surface. The solid surface may have
several characteristics that are important in the
attachment process. Characklis (1990), noted that the
extent of microbial colonization appears to increase as
the surface roughness increases. This is because shear
355
forces are diminished, and surface area is higher on
rougher surfaces. According to Fletcher and Loeb
(1979); Pringle and Fletcher (1983); & Bendinger et al.
(1993), the physicochemical properties of the surface
may also exert a strong influence on the rate and extent
of attachment.
Most investigators have found that the
microorganisms attach more rapidly to hydrophobic, non
polar surfaces such as teflon and other plastics than to
hydrophilic materials such as glass or metals. Other
characteristics of the aqueous medium, such as pH,
nutrient levels, ionic strength and temperature, may play
a role in the rate of microbial attachment to a substratum.
Several studies have shown a seasonal effect on bacterial
attachment and biofilm formation in different aqueous
356
systems (Fera et al., 1989; Donlan et al., 1994). This
effect may be due to water temperature or to other
unmeasured, seasonally affected parameters. Fletcher
(1988), found that an increase in the concentration of
several cations (sodium, calcium, lanthanum, ferric iron)
affected the attachment of Pseudomonas fluorescens to
glass surfaces, presumably by reducing the repulsive
forces between the negatively charged bacterial cells and
the glass surfaces. Cowan et al. (1991), showed in a
laboratory study that an increase in nutrient
concentration correlated with an increase in the number
of attached bacterial cells.
According to Watnick et al. (2000), the
bacterium first approaches the surface so closely that
motility is slowed. The bacterium may then form a
357
transient association with the surface and/or other
microbes previously attached to the surface. This
transient association allows it to search for a place to
settle down. When the bacterium forms a stable
association as a member of a micro colony, it has chosen
the neighborhood in which to live. Finally, the buildings
go up as a three dimensional biofilm is erected.
Occasionally, the biofilm associated bacteria detach
from the biofilm matrix. Thus, when the bathing medium
is rich in nutrients, a bacterium will attach to any
available surface, while in a nutrient poor environment
the bacterium will attach preferentially to a nutritive
surface. This adaptation ensures that the bacterium will
maximize access to nutrients in both nutrient poor and
nutrient rich aqueous environments. These interactions
are thought to be essential for successful plaque
358
formation (Klier et al., 1998; Kolenbrander et al. 1995;
Whittaker et al. 1996).
Acording to Xu et al. (1998) and Okabe et al.
(1999), the environment in a biofilm is not
homogeneous. Microelectrode measurements have
shown that the oxygen concentration and pH fall in a
biofilm as the substratum is approached. As the success
of a biofilter depends on the growth and maintenance of
microorganisms (biomass) on the surface of filter media,
it is necessary to understand the mechanisms of
attachment, growth and detachment on the surface of the
filter media. Van Loosdrecht (1990) described the
mechanisms by which microorganisms can attach and
colonize on the surface of the filter media of a biofilter
are (i) transportation, (ii) initial adhesion, (iii) firm
359
attachment and (iv) colonization. The transportation of
microorganisms to the surface of the filter media is
further controlled by four main processes, (a) diffusion
(Brownian motion), (b) convection, (c) sedimentation
due to gravity and (d) active mobility of the
microorganisms.
As soon as the microorganisms reach the surface,
initial adhesion occurs which can be reversible or
irreversible depending upon the total interaction energy,
which is the sum of van der walls force and electrostatic
force. The DLVO (Derjaguin-Landau-Verwey-
Overbeek) theory is often used to describe the adhesion
of the microorganisms on the surface of the filter media.
The processes of firm attachment and colonization of
microorganisms depend on influent characteristics such
as organic type and concentration and surface properties
360
of the filter media. The steric effects, hydrophobicity of
the microorganisms, contact angle and electrophoretic
mobility values are taken into consideration to estimate
the attachment of microorganisms on the surface of filter
media. The specific detachment rate coefficient
increased as inert particle concentration and particle
Reynolds number (i.e., turbulence) increased and the
turbulence and attrition of bed fluidization appeared to
be dominant detachment mechanisms.
The other parameters of filter materials include
volume, surface area and specific surface area which
play a vital role in performance of pollutants removal. In
the present study an attempt was made to utilize lower
volume of filter material to get maximum efficiency of
pollutant removal. In this context volume of the size
361
10% - 40% to the reactor volume were considered. Even
though constant volume rates were applied for
experimentation the volume of individual objects were
varied from each other. Filter material clay ball had
highest volume per unit and nylon thread had lowest
volume per unit. The size and shape of the filter material
is responsible for change in the volume. The volume
quantity is directly related to the economics of the filter
material in the treatment of waste water. The lower
volume quantity results in lesser cost of the filter
material. The increase of volume quantity is favourable
for increase of elimination capacity of the pollutants.
Hence, optimization of filter material is essential.
Significant and promising results were obtained for 20%
volume of corn cobs and 30% volume of nylon threads.
362
According to Ødegaard (1975), the standard
filling fraction (or) the volume of filter material is 67%.
He conducted experiments with the filter material having
specific surface area 465 m2/m
3. The smaller carrier
/filter material will need smaller reactor volume at a
given loading rate even though the filling fraction is
same. Dempsey et al. (2006), reported that 46 – 62% of
TSS removal efficiency and 41 – 56% of BOD removal
efficiency can be obtained using 30% volume of glassy
coke 1mm size particles as filter material. Pak and
Chang (2000), reported that removal of 12gms P/m3 of
total phosphorus and 60gms N/m3 of total nitrogen using
ceramic beads of volume 50% and size of 3 – 5mm
during the process of treatment. The removal efficiency
of pollutants is directly proportional to the surface area,
where the availability of more surface area is useful for
363
attachment of more number of microorganisms and
results in elimination of more pollutants. In the present
study, filter material corn cob had highest surface area
and granite chip had lowest surface area. The elimination
capacity of the pollutants was also same. It is evident
that elimination capacity directly depends on surface
area.
The filter material nylon thread has highest
specific surface area i.e., 2007.14 m2/m
3 followed by
corn cobs and least for plastic balls and clay balls. The
elimination capacity was also more for nylon thread and
corn cobs and least for plastic ball. Even though, the
specific surface area was more than sufficient for granite
chips the elimination capacity of pollutants was not
satisfactory. The non-biogenicity and smooth texture of
364
the material might be the reasons for lower elimination
efficiencies. According to Michael et al. (1999), packing
material with high specific surface area i.e., from 300 to
1,000 m2/m
3 provides favorable living conditions for the
resident microbial population (ensured by high retention
capacities of water and nutrients), and favorable
immobilization for the micro flora involved. Valentis
and Lesavre (1989), stated that high specific surface area
1000-1500 m2/m
3 of the granular media allows for a high
biomass concentration can be maintained within the
system. The removal of solids in the media negates the
need of secondary clarifiers. However, backwashing is
required to remove excess biomass and captured solids.
Anthony et al. (1998), reported that 3.2 times more
removal efficiency of total ammonical nitrogen by
weight per day per unit volume of the reactor was
365
obtained using polystyrene beads of volume 12% with
specific surface area of 3936 m2/m
3. The characteristics
that affect the choice of the packing medium include, its
availability in the region where the biofilter is built
(transport fees may turn a competitive medium into an
uncompetitive one), its abundance, and hence its
price/kg, its compaction (to minimize the pressure drop
across the bed to decrease running costs), its life
expectancy (to replace the bed involves extra
maintenance costs, an interruption of the treatment and a
re-adaptation period), its specific area to increase
adsorption. Swanson and Loehr (1997), emphases the
importance and choice of the appropriate packing
medium. The range of packing media is large and
includes compost, heather, coir, woodchips, synthetic
materials or granulated activated carbon (GAC).
366
In the present study, an attempt was made to
utilize various filter materials which were readily
available, low cost, effective and novel filter materials.
The cost of the filter material show enormous effect on
economics of treatment systems. The filter material i.e
corn cobs are available at free of cost, which cannot be
used for any kind of other purposes except combustion
process. The remaining filter materials viz. granite chips,
clay balls, sintered glass cylinders, wood chips are
available at lower cost comparatively. The filter
materials like nylon threads and plastic balls are
expensive when compared to the remaining filter
materials. Significant and promising results were
obtained for corn cobs and nylon threads only.
367
The significant quantity of biofilm formation had
taken place on filter materials like corn cobs followed by
nylon threads and wood chips. The biofilm formation on
remaining filter materials was not in significant quantity.
Various other physical characteristics like physical
nature, porosity, aberration and surface tension might be
the reasons for improper formation of biofilms on other
filter materials and explanation is beyond the scope of
present work. The cost of wastewater treatment is
dependent on local circumstances. In the big cities,
however, the space required for the plant is very
determining for the investment cost. Compact treatment
alternatives methods are consequently more and more
being favored. Biofilm systems are replacing activated
sludge systems and high-rate separation techniques are
replacing traditional settling tanks (Chaudhary et al.,
368
2003). There are several factors that have to be taken
into account when evaluating different treatment
methods for wastewater treatment such as (1) treatment
efficiency, (2) cost, (3) area requirement, (4) sludge
production and (5) sustainability (e.g. ecological impact
and energy use). Bacteria experience a certain degree of
shelter and homeostasis when residing within a biofilm.
Smith and Hardy (1992), reported that biofilters
require 3 time less aeration volume than activated sludge
units and 20 times less than trickling filters for a given
degree of treatment. In the present study, aeration was
not provided for treatment system. Hence, the
mechanical and electrical revenue can be economized.
According to Hozaiski and Bouwer (1998), biofilters are
different from conventional gravity filters and can be
369
used to treat water in a fine porous medium where the
purification occurs, and can not only filter suspended
solids, but also increase the degradation of organic
matter using the fixed film biomass. These two
mechanisms ultimately result in the progressive clogging
of the biofilter, which must then be washed clean.
According to Leopoldo and Tom (1999), when granular
media is used, the system is capable of removing organic
matter and suspended solids from the wastewater and
there is no need of solid separation stage and
sedimentation tanks.
4.6.2.2 Hydraulic retention time (HRT)
Hydraulic retention time (HRT) is a vital
parameter in sewage treatment process. The efficiency of
the pollutants removal increased with the increase of
370
HRT for all types of filter materials. However, low HRT
will be useful for treating the sewage because of heavy
quantity. In the present study various hydraulic retention
times i.e., 8, 9, 10, 11 and 12 hours were studied for
obtaining optimum retention time. The highest removal
efficiency of biochemical oxygen demand (78.14%) with
less hydraulic retention time of 9 hours was obtained
using corn cobs as biofilter media (Fig 43, page 552). It
was preceded by nylon threads (10 hours), wood chips
(10 hours), sintered glass cylinders (10 hours), clay balls
(10 hours), plastic balls (12 hours) and granite stones (12
hours). Oh, et al. (2001), reported that the denitrification
rate of 67.26% for 2 hours HRT and 75% per 4 hours
HRT using plastic pall rings as filter media of 70%
volume and 340m2/m
3 specific surface area in the
presence of alkaline pH. According to Chen et al.,
371
(2000), the conventional treatment processes generally
require a long residence time to retain slow growing
organisms such as denitrifyers in the system. Moreover,
a relatively large volume of reaction is necessary to
obtain a high reactor capacity. The reactor capacity can
be improved by increasing the biomass retention time
using an immobilized cell system. In the present study,
an attempt was made to minimize the residence time or
hydraulic retention time. This may be helpful in trouble
shooting of various problems in operation of treatment
systems with respect to residence time.
According to Isaka et al. (2007), the application
of cell immobilization techniques to the wastewater
treatment process has recently gained much attention.
These techniques not only offer a high cell concentration
372
in the reactor tank for increasing efficiency, but also
facilitate the separation of liquids and solids in the
settling tank (Chen et al., 2000). Metcalf and Eddy
(1995), stated various variations in flow rates. Minimum
flow occurs during the early morning hours when water
consumption is lowest and when the base flow consists
of infiltration and small quantities of sanitary
wastewater. The first peak flow generally occurs in the
late morning when wastewater from the peak morning
water use reaches the treatment plant. A second peak
flow generally occurs in the early evening between 7 and
9 p.m but this varies with size of the community and
length of the sewer. The hydraulic design of both
collection and treatment facilities is affected by
variations in wastewater flow rates. In view of the above
situation it is essential to treat wastewater within 8 hours
373
of HRT. Out of 24 hours in a day, a 8 hours hydraulic
retention time treatment will be more useful in terms of
operations and two batches of 8 hours HRT can be
applied per day in which peak hour flow rates can be
managed. The remaining 8 hours per day can be used for
unit operations of treatment systems.
4.6.2.3 Time period
Time period also plays a significant role in terms
of economics of treatment system using biofilter media.
The longevity of filter media is much more helpful for
high removal efficiency of pollutants. It also has an
effect on quantity of filter media usage where repeated
replacements of fresh filter media are necessary. The
highest removal efficiency of biochemical oxygen
demand (85.19%) with maximum time period was
374
obtained using nylon thread as biofilter media for 60
days (Fig 44, page 553). It was followed by wood chip
(50 days), corn cob (40 days), sintered glass cylinder (30
days), clay ball (30 days), stone (60 days) and plastic
ball (60 days).
Even though stone and plastic balls are viable for
60 days their biochemical oxygen demand removal
efficiency were very much less when compared to other
filter media. In the present study, the effect of filter
media for removal efficiency of pollutant varied from 30
days to 60 days. Filter material like corn cob showed
best removal efficacy of pollutants up to 40 days and it
does not mean that after 40 days of operation there is no
need of neither replacing filter media nor damage of
filter media. A step of back wash is essential to clean the
375
filter material. The effect of back wash on the treatment
process and total life time (longitivity) of filter material
are beyond the scope of present study.
4.6.2.4 Food to microorganism ratio (F/M)
Food to microorganism ratio was calculated
using the formula F/M ratio = BOD (mg/L) / VSS
(mg/L). In the present study, low F/M ratio was obtained
for corn cob material and it was followed by wood chips,
nylon thread, clay balls, sintered glass cylinders, plastic
balls and stone material (Table – 81, page 495; Fig. 45,
page 554). The F/M ratio in Dempsey et al. (2006),
experimentation using 1mm glassy coke as filter media
with 30% volume was 0.001. According to Warith et al.
(1998), to improve the self-purification capacity, a low
F/M ratio is desirable. The food to microorganism ratio
is an empirical parameter frequently used for the design
376
of activated sludge processes. According to Metcalf and
Eddy (1991) and Nicolella et al., (2000), the typical
values for conventional systems range from 0.3 to 1.5 kg
COD/ kg SS/day.
Biofiltration is a pollution control technique
using living microorganisms for bioremediation process
of pollution. Biofiltration is an extending phenomena of
adsorption. Adsorption processes are widely applied for
separation and purification because of the high
reliability, energy efficiency, design flexibility,
technological maturity and the ability to regenerate the
exhausted adsorbent. Various kinds of natural and
synthetic packing materials are used in biofilters.
Biofilms are developed on biofilters. A biofilm is an
assemblage of microbial cells that is irreversibly
377
associated (not removed by gentle rinsing) with a surface
and enclosed in a matrix of primarily polysaccharide
material. According to Deibel (2001) and Kumar (1998),
biofilm can exist on all types of surfaces such as plastic,
metal, glass, soil particles, wood, medical implant
materials, tissue and food products. Bacterial attachment
is mediated by fimbriae, pilli, flagella and EPS that act to
form a bridge between bacteria and the conditioning
film. Biofilms, in nature, can have a high level of
organization and they may exist in single or multiple
species communities and form a single layer or 3-
dimensional structure.
Microorganisms can be present in biotreatment
processes as discretely dispersed cells, as flocs or as
biofilms. The latter two are by far the most common and
378
both flocs and films can be considered as matrices of
naturally immobilized cells. Since immobilized
microbial cells were first investigated, there have been
repeated claims that immobilization results in enhanced
performance; claims which will most probably be
explained on the basis of phenotypic responses to
environmental gradients at a future date. The bacterial
growth and activity is substantially enhanced by the
incorporation of surfaces to which microorganisms could
attach (Bottle effect). Cell surface hydrophobicity,
presence of fimbriae and flagella and production of EPS
all influence the rate and extent of attachment of
microbial cells. Fimbriae play a role in cell surface
hydrophobicity and attachment, probably by overcoming
the initial electrostatic repulsion barrier that exists
between the cell and substratum (Corpe, 1980). In light
379
of these findings, cell surface structures such as fimbriae,
other proteins, LPS, EPS and flagella all clearly play an
important role in the attachment process.
Metcalf and Eddy (1991), reported that biofilter
was first introduced in England in 1893 as a trickling
filter in wastewater treatment, and since then, it has been
successfully used for the treatment of domestic and
industrial wastewater. Originally, biofilter was
developed using rock or slag as filter media. However, at
present several types and shapes of plastic media are also
used. There are a number of small package treatment
plants with different brand names currently available in
the market in which different shaped plastic materials are
packed as filter media and are mainly used for treating
small amount of wastewater (e.g. from household or
380
hotel). Irrespective of its different names usually given
based on operational mode, the basic principle in a
biofilter is the same i.e., biodegradations of pollutants by
the microorganisms attached onto the filter media. The
idea behind a biofilter is to let microorganisms degrade
pollutants from the air and use these substances as their
primary carbon and energy source. The key to a
successful biofilter operation is to create a health
ecosystem in the filter, by controlling parameters like
moisture content, pH, temperature, access to oxygen and
nutrients. The choice of filter material is fundamental
and in recent years various synthetic packing materials
indeed do not contain microorganisms or nutrients,
which therefore must be added. According to Miao et al.,
(2005), wood seems to be a suitable biofilter medium
since it is cheap, develops low pressure-drops, has good
381
mechanical properties and offers a seemly habitat for
microorganisms. The pioneer in the investigation of the
behaviour of biofilters was Ottengraf (1983). He
assumed that the kinetics of the biodegradation which
takes place in the biolayer is zero order.
According to Chaudhary et al. (2003), any type
of filter with attached biomass on the filter media can be
defined as a biofilter. Bacterial masses attached onto the
filter media as biofilm oxidize most of the organics and
use it as an energy supply and carbon source. Biofilter
has been successfully used for air, water, and wastewater
treatment. Because of its wide range of application,
many studies have been done on biofiltration system in
the last few decades. However, theoretically it is still
difficult to explain the behavior of a biofilter. The
382
growth of different types of microorganisms in different
working conditions makes it impossible to generalize the
microbial activities in a biofilter. The biofilters operated
at different filtration rates and influent characteristics can
have diverse efficiency for different target pollutants. In
a biofiltration system, the pollutants are removed due to
biological degradation rather than physical straining as is
the case in normal filter.
With the progression of filtration process,
microorganisms (aerobic, anaerobic, and facultative
bacteria, fungi, algae and protozoa) are gradually
developed on the surface of the filter media and form a
biological film or slime layer known as biofilm.
Chaudhary et al., (2003) reported that the development
of biofilm may take few days or months depending on
383
the influent organic concentration. The crucial point for
the successful operation of a biofilter is to control and
maintain a healthy biomass on the surface of the filter.
Since the performance of the biofilter largely depends on
the microbial activities, a constant source of substrates
(organic substance and nutrients) is required for its
consistent and effective operation.
There are three main biological processes that
can occur in a biofilter viz., (i) attachment of
microorganism, (ii) growth of microorganism and (iii)
decay and detachment of microorganisms. As the
success of a biofilter depends on the growth and
maintenance of microorganisms (biomass) on the surface
of filter media, it is necessary to understand the
mechanisms of attachment, growth and detachment on
384
the surface of the filter media. According to Leson and
Smith (1997), biofiltration relies on phenomena which
occur in nature, but at slower rates. Microorganisms
release CO2 in the atmosphere. The accumulation of
other bye products in the filter medium is not significant.
After use, the packing medium is unlikely to be
classified as hazardous waste. Flemming and Winglinder
(2001), reported that the complexity of biofilms depends
on a variety of factors such as nature of both substrate
and support material and the diversity of microorganisms
involved in the treatment process.
According to Liu et al. (2001), biomass and
microbial activity in a biofilter are two critical
parameters, which determine the reactor’s performance
in water treatment and have become the focus of interest
in the scientific community due to the development of
385
modern analytical techniques. Boifilms are of two types
i.e., active biofilms and inactive ones. Different from
inactive biofilms, active ones have direct influence on
the substrate degradation rate, which is proportional to
the surface areas of supports (Liu and Capdeville, 1996).
Biofilm spatial structures can be studied by using a 3-D
image technology as a bridge between light microscopy
and electron microscopy (Lazarova and Manen, 1995).
Mary et al. (2000), reported that EPS plays
various roles in the structure and function of different
biofilm communities. Moreover, it is quite possible that
EPS plays a different role in similar microbial
communities under different environmental conditions.
According to Gilbert et al. (1997), the EPS matrix also
has the potential to physically prevent access of certain
386
antimicrobial agents into the biofilm by acting as an ion
exchanger, thereby restricting diffusion of compounds
from the surrounding milieu into the biofilm. According
to Flemming (1993), EPS has also been reported to
provide protection from a variety of environmental
stresses, such as UV radiation, pH shifts, osmotic shock
and desiccation. According to Flemming et al., (2000),
biofilms are composed primarily of microbial cells and
EPS. EPS may account for 50% to 90% of the total
organic carbon of biofilms and can be considered the
primary matrix material of the biofilm. EPS is also
highly hydrated because it can incorporate large amounts
of water into its structure by hydrogen bonding. EPS
may be hydrophobic, although most types of EPS are
both hydrophilic and hydrophobic (Sutherland, 2001).
EPS may also vary in its solubility. Sutherland (2001),
387
noted two important properties of EPS that may have a
marked effect on the biofilm. First, the composition and
structure of the polysaccharides determine their primary
conformation. Second, the EPS of biofilms is not
generally uniform but may vary spatially and temporally.
Leriche et al. (2000), used the binding specificity
of lectins to simple sugars to evaluate bacterial biofilm
development by different organisms. EPS production is
known to be affected by nutrient status of the growth
medium i.e., excess available carbon and limitation of
nitrogen, potassium or phosphate promote EPS synthesis
(Sutherland, 2001). Slow bacterial growth will also
enhance EPS production (Sutherland, 2001). Because
EPS is highly hydrated and it prevents desiccation in
some natural biofilms. EPS may also contribute to the
388
antimicrobial resistance properties of biofilms by
impeding the mass transport of antibiotics through the
biofilm, probably by binding directly to these agents
(Donlan, 2000). Shoji et al. (2008), reported that low
assimilable organic carbon hindered heterotrophic
bacteria and favored autotrophs and oligotrophs.
Roeselers et al. (2008), reported that a matrix of
substances secreted by phototrophs and heterotrophs
enhances the attachment of biofilm community.
Andersson et al. (2010), studied the influence of
microbial interactions and polysaccharide compositions
on nutrient removal activity in multi species biofilms,
formed by strains found in wastewater treatment
systems. In this report, relationship between biofilm
formation, denitrification activity, phosphorus removal
389
and the composition of EPS, exopolysaccharides and
bacterial community was investigated using biofilm of
denitrification and phosphorus removing strains of
microbes. Denitrification activity in biofilms increased
with the amount of biofilm, while phosphorus removal
depended on bacterial growth rate. Peitzsch et al. (2008),
investigated Escherichia coli biofilms using real time
analysis and reported that microbial communities grow
more stably when they are associated with surfaces or
organized in aggregates. This advantage of biofilms is
technically exploited for the degradation of xenobiotics
or in biocatalysis, where the fixed biomass has the added
advantage of easier separation of excreted products.
Appropriately treated domestic sewage can be
further used as ideal for irrigation and fertilization
390
purposes in particularly the semiarid climate region. In
addition to an increased availability of an additional
source of irrigation water, treated sewage contains
valuable plant nutrients (N, P, K), while non-controlled
environmental pollution is prevented. In fact, the
agricultural application can be considered as a tertiary
treatment step. In such approach, water pricing can be
included, distributing the costs of treatment both over the
community and farmers, as polluters and beneficiaries,
respectively (Lier et al., 2002). Bashan et al. (1993),
suggested that when considering inoculation with
microbes, the first objective is to find the best microbe
available. The second one is a study of the specific
inoculum formulation that determines the potential
success of the inoculum (Fages, 1992). Once a feasible
strain is chosen, it is optimized, tested and applied with
391
the help of a carrier material. According to Oh and
Bartha (1997), it is necessary to allow the biodegradation
of all components, sometimes to add new strains to the
packing medium, which already contains
microorganisms.
The acclimatization of microbial communities to
the bioreactor environment is a critical period which
influences the long-term functioning of bioreactors. As
such, it has been extensively studied in waste gas and
wastewater treatment systems (Tresse et al., 2002). In
the present study, an attempt was made to utilize
materials of no use and low cost materials as biofilter
materials, effective strains of microorganisms in limited
space and without high infrastructure and operational
maintenance like aeration etc., for the treatment of
392
domestic wastewater. The results were promising and the
microorganisms & filter materials used in the present
study are helpful in the bioremediation of sewage to
achieve effluents standards of pollution control board
and the concept may be useful to use at small scale
treatment systems with further research of various
aspects.
The nature of the packing material in biofilters is
an important factor for the success in the design and
operation of biofilters. The materials studied were
chosen according to performance studies conducted
earlier in the field of biofiltration. This study included
both organic and inorganic (or synthetic) materials along
with few other materials like corn cobs, sintered glass
cylinders. The novelty in using these materials includes
393
providing high specific surface area, durability and
economic feasibility.
In general, these studies concluded that high
removal efficiencies in biofilters are strongly related to
packing material properties irrespective of physical and
chemical properties of the materials. The nature of the
filter material, which may be organic, natural inorganic
or entirely synthetic, is a crucial factor for the successful
application of biofilters and biotrickling filters. The
performance of these materials affects the frequency at
which the medium is replaced and other key factors such
as bacterial activity (Prado et al., 2009). Among the
natural carriers reported, compost, peat, soil and wood
derivatives are the most extensively used, while
activated carbon (AC), perlite, glass beads, ceramic
394
rings, polyurethane foam, polystyrene and vermiculite
are some of the several synthetic or inert carriers which
have been studied (Kennes and Thalasso, 2001).
In the present work, 7 packing materials viz.,
granite stones, clay balls, sintered glass cylinders, corn
cobs, wood chips, nylon threads and plastic balls were
used as support media in biofiltration and were
compared to evaluate their suitability. For this purpose, a
comprehensive study of physical and chemical
parameters for common packing materials used in
biofiltration has been performed. In addition, a relative
classification of the packing materials is provided per
each parameter studied.
Specific surface area, particle size, density,
particle stability and adsorption are some of the most
395
important characteristics in relation to physical
characteristics of the filter media in biofiltration.
Volume, HRT and time period are the operational
parameters studied in evaluating biofilter media.
A high specific surface area is needed to achieve
high mass transfer velocities which is required to keep
an optimal activity of the immobilized microorganisms.
A high adsorption capacity is recommendable to buffer
intermittent loads, while a low purchase cost is directly
linked with biofilter economical viability. Packing
material particles vary in size, which affects important
media characteristics such as the resistance to liquid and
air flow and the effective biofilm surface area. If the size
of the particles is small large specific surface areas
essential for mass transfer are provided as it happens in
396
case of nylon threads. However, smaller particle sizes
also create a larger resistance to liquid flow and, thus,
larger operating costs due to the electrical power
consumption of the blower. Conversely, large size
particles favour liquid flows but reduce the number of
potential sites for the microbial activity as it happened in
the case of corn cobs. Adu and Otten (1996) have
reported that particle size is a parameter even more
influential to the performance than the gas flow rate.
Thus, the relative importance of packing material
properties can be different depending on the
characteristics of the system and its operation. In the
present study, nylon threads showed high specific
surface area and it was followed by corn cobs. The
pollution reduction efficacies of pollutants were also
high for these two materials when compared to others.
397
The physico-chemical parameters of wastewater
play an important role in the selection of biofilter
material. The characteristics of wastewater influence the
degradation of organic material. In the present study,
nylon threads are synthetic in nature and they are non
biodegradable. Corn cobs also showed good pollution
reducing capacities even though it is biodegradable in
nature. Further research is warranted in this context i.e.,
utilization of corn cobs in practical scale and their
relative purification efficiency in varied wastewater
compositions.
The surface area of biofilter material has a great
influence on the volume of the reactor. The smaller the
particle size, greater the surface area offered to microbial
attachment. Hence, HRT decreases. This has vast
398
influence on the investment on the size of the reactor
(treatment system), facilitating an economic waste
treatment system. In the present study, an attempt was
made to utilize filter materials with low volume,
minimum possible HRT and maximum time period for
domestic sewage treatment. Out of seven filter materials
corn cob with 20% volume, 9 hours HRT and 40 days
time period showed good elimination capacities of
pollutants along with nylon threads with 30% volume,
10 hours HRT and 60 days time period. As the primary
target is to achieve pollution control parameters set by
government), the time of treatment can be further
reduced. The results of the microbial treatment have
been assessed using equipment like electron microscopy,
LCMS, SDS PAGE etc., to achieve objective results.
399
Furthermore, since the economical viability is a
key aspect to choose a suitable material, the purchase
costs and operating costs related to pressure drop across
the packed bed were also considered. In addition to
operating costs, the purchase cost of packing materials
has a significant impact in overall costs, not only
because of the high volumes usually required for
biofilter construction but also because of packing
materials replacement due to limited durability.
However, the estimated durability of synthetic filter
materials is generally larger than organic packing
materials. This is due to superior mechanical and
chemical resistance offered by synthetic materials which
avoids degradation in short periods of time. Special
attention has to be paid to the packing materials selected,
as it is the main parameter influencing the medium
400
replacement cost, and one of the main factors affecting
investment costs (Prado et al., 2009).
In the present study, corn cobs and nylon threads
showed good purification capacities than the remaining
filter materials. Corn cobs were available free of cost and
all other materials along with nylon threads were more
costly than the cobs. The actual economics were not
studied in the present work and corn cobs may be the
best compared to the rest, in terms of its availability and
purification capacities of pollutants.
During the 1980s, intensive scientific research
was started on bioreactors, leading to a quick
improvement in the knowledge of the principles of
biofiltration and, concomitantly on the design and
401
development of innovative bioreactor designs. Now-a-
days bioreactors are a promising alternative to traditional
physical and chemical gas treatment technologies,
mainly due to their high efficiency and competitive cost
(Devinny et al., 1999). Several studies have pointed out
that one of the main advantages of bioreactors is the
reduction of the operating costs (Zuber et al., 1997; Jorio
and Heitz, 1999; Deshusses and Webster, 2000; Gao et
al., 2001; Gabriel and Deshusses, 2004). Only a few in-
depth studies aimed at assessing investment and
operating costs of biological treatment systems have
been published so far. Among them, Gerrard (1996)
developed a model which allows determining the total
costs of a biofilter as a function of its bed height and air
velocity. Also, Deshusses and Cox (1999) developed a
model which allows selecting the most cost-effective
402
bioreactor design and operating conditions for
biotrickling filters. However, none of them have been
extensively applied in full-scale operations. The present
work serves as a tool that allows to assess the
economical viability of a biological wastewater treating
system.
4.7 Chapter VII
4.7.1 Electron Microscopy studies
In the present study, samples of high pollutant
elimination capacities were subjected to electron
microscopic studies and observed for results. It was
observed that filter materials corn cob and nylon thread
showed maximum elimination capacity of pollutants. It
was observed that microbial cell adherence and
attachment was maximum for corn cob material when
403
compared to nylon thread (Fig 46 – 53, page 555 - 562),
when observed at various magnifications. It was also
evident that the matrix of corn cob is highly complex
when compared to surface of nylon thread (Figs. 54 and
55, page 563 & 564). It envisaged that, the nature of
filter material has an effect along with the surface area of
the filter material in the pollution elimination capacity.
In the present study, corn cob provides 1046.17 m2/m
3
specific surface area and nylon thread provides 2007.14
m2/m
3 specific surface area and both the materials
showed similar pollution elimination capacities. The
nature of the corn cob is biogenic which provides
suitable conditions for adherence of microorganisms.
Adherence of the microbial cell to the surface of the
filter material is the first and important factor for the
biofilm formation.
404
Prokaryotes in natural environments form
biofilms, which are benthic assemblages of a variety of
microorganisms embedded within their extracellular
mucilage. Biofilms are firmly attached to surfaces such
as aquatic sediments. Quorum sensing by the many
microbes in a biofilm is a collective decision making and
cooperation for responding to internal and external
parameters affecting the community. This
communication is based on chemical signaling affecting
gene expression of the microorganisms. Microorganisms
situated in a biofilm change behaviours and metabolic
activities to comply with the requirements of the entire
biofilm cooperative. Consequently, reconstruction of the
evolution of prokaryotes in Earth history must consider
the biofilm way of microbial life. Biogenic sedimentary
structures might not represent certain microbial groups,
405
but in fact may be relics of modified cooperative
microbial activities. Future research should focus on
detectable biosignatures caused by biofilm consortia as a
whole instead of on the appearance or extinction of
individual microbial groups. Such sedimentary structures
as stromatolites and microbially induced sedimentary
structures (MISS) are intrinsically controlled by
biofilms, but also affected by extrinsic (environmental)
conditions (Nora et al., 2013).
The physical properties of the biofilm are largely
determined by the EPS, while the physiological
properties are determined by the bacterial cells (Dirk and
Paul, 2013). Bacterial adhesion is generally recognized
as the first step in biofilm formation, Bacteria adhere to
virtually all natural and synthetic surfaces (Hall et al.,
406
2004). There are a number of different reasons for
bacteria adhering to a surface viz., “Adhesion to a
surface is a survival mechanism for bacteria”. Nutrients
in aqueous environments have the tendency to
accumulate at surfaces, giving adhering bacteria a
benefit over free floating, a link has been described
between strong adhesion forces between bacteria and
substratum surfaces yielding membrane stresses and the
percentage of dead cells on a surface for which the term
“stress de-activation” was coined (Liu et al., 2008).
Adhesion forces at the proposed transitions between the
different regimes are all approximate because adhesion
forces tend to strengthen considerably during the first
minutes after contact, yielding a switch from reversible
to irreversible adhesion. Microbiologically, this switch
has been associated with the production of EPS in
407
response to a surface (Hall et al., 2004), but EPS
production in response to adhesion likely occurs much
later on during growth, as completely inert polystyrene
particles also demonstrate this initial bond strengthening
(Busscher et al., 2010). Upon first approach of a
bacterium to a surface, it becomes attached to a layer of
highly viscous water adjacent to the surface that is
subsequently slowly penetrated to allow stronger contact
with the surface, after which protein structures on the
cell surface re-orient themselves to allow optimal
binding. Since it is unlikely that metabolic processes and
phenotypic changes occur within minutes, we envisage
that adhesion forces after physico-chemical
strengthening represent the transition forces between the
three adhesion force regimes. According to Busscher et
408
al., (2012), three adhesion forces are regimes dictating
the bacterial response to a substratum surface.
4.7.2 Electrophoresis of proteins
The objective of this study was to investigate the
proteins profiles in biofilm, raw sewage, treated sewage
and consortium using SDS-PAGE. Numerous distinct
protein bands were obtained, indicating that extracellular
proteins present in the samples were well separated by
SDS-PAGE. Protein profiles were different between the
four extracts viz., biofilm, consortium, raw sewage and
treated sewage indicating that extracellular proteins
were not the same that were released. Although there
were some common proteins present in all four extracts.
409
In the present study, molecular weight of proteins
was determined using known marker and compared each
other. It envisages that the type of proteins present in
consortium with molecular weights 140 kd, 36 kd, 27 kd,
24 kd were also present in biofilm, which was a strong
evidence that consortium used in the treatment process
was also a part of biofilm. Similarly, the proteins present
in raw sewage with molecular weights 247 kd and 25 kd
were also present in biofilm. Hence, it may possible that
biofilm formation is a complex phenomena which forms
with the help of various microorganisms present in the
treatment process. The type of proteins present in treated
sewage with 24 kd was a low molecular weight
substance which was also present in remaining samples
(Fig 56, page 565).
410
All profiles had a number of larger proteins in the
250 kDa range, and some distinct bands in the range
between 24 and 140 kDa. They also showed small bands
at around 24 kDa. These protein bands are visible in both
consortium and biofilm, signifying that the consortium is
the source of these proteins. Yet, the profiles between
biofilm and raw sewage are consistently different, with
some proteins only appearing in the consortium but not
in the raw sewage. This indicates that they are soluble
microbial products produced by microorganisms in
consortium.
There are enough protein bands in biofilm,
consortium and raw sewage to question the prevailing
assumption that most of the proteins in biofilm are
soluble microbial product (SMPs) and have origins in
411
consortium (Barker and Stuckey, 1999; Drewes and Fox,
2000; Drewes et al., 2001). It should be noted that SDS-
PAGE is not a method of measuring proteins. While it is
true that more concentrated proteins will have darker and
thicker bands, SDS-PAGE is unable to measure proteins.
It envisages that the protein profiles from biofilm,
consortium has a high diversity of proteins. These data
are unable to resolve that question, but the darkness of
the bands suggests that recalcitrant proteins constitute a
large percentage of the microbial proteins. No other
proteins were present in the treated sample and it may be
said that the treatment process is said to be proper. The
Rf values were calculated and tabulated (Table 82 – 83,
page 496 & 497) and graph was drawn for Rf values (Fig
57, page 566).
412
Some proteins in the 25 - 35 kDa range is clearly
visible in all the sources, is evidenced by the high degree
of similarity between the various sources. Other
researchers have similarly found that bioavailable, low
molecular weight, forms of dissolved organic nitrogen
(DON) were lost in secondary effluent (Pehlivanoglu
and Sedlak, 2004). The same research group asserts that
most treatment plants will not remove low molecular
weight, hydrophilic compounds, and that these low-
molecular weight wastewater effluents could act as
precursors during water reuse or reclamation. They
conclude that more research needs to be done to find
physical or chemical treatment processes to remove
bioavailable DON or that operating conditions may be
able to be altered to decrease the concentration
(Pehlivanoglu-Mantas and Sedlak, 2008).
413
Identifying these strongly expressed proteins and
understanding their biochemical roles in sewage
treatment may contribute to a better engineering
application. The success of SDS-PAGE might itself be a
meaningful result since the application of SDSPAGE
into complex environmental samples such as sewage,
biofilm is generally known as a difficult task. The
identification and characterization of SDS PAGE
proteins was beyond the scope of present study and it
can be carried out in further experimentation in future.
Further characterization of the low molecular weight
proteins that contribute to this low molecular weight
DON could provide clues as to how to reduce the release
of this fraction of material in wastewater effluent.
414
Park et al., (2008), stated that identification of
proteins from samples like field activated sludge is a
challenge, because the genomes of most of activated
sludge microorganisms have not yet been sequenced.
However, the development of metagenomic analysis and
mass spec technologies may bring meaningful protein
identification work in the near future.
4.7.3 LCMS studies
The LC/MS is used in many applications,
because of its ability to detect a wide range of
compounds with great sensitivity and specificity. One
fundamental application of LC/MS is the determination
of molecular weights. In the present study, four samples
viz., raw sewage, treated sewage, consortium and
biofilm were subjected to LC MS. The biofilm was taken
415
from corn cob surface. The m/z values ranging from 200
– 1000 m/z value in positive mode and 200 – 600 m/z
value in negative mode were considered. Based on the
results it was found that the molecular ion (M) had the
molecular weight of 288 in positive mode and 266 and
294 in negative mode for all the samples (Fig 58 – 65,
page 567 - 574). The identification and characterization
of proteins from the samples was beyond the scope of
present study and it can be done in further research.
The data reported by Park et al. (2008), from
LC/MS/MS studies of sewage sludge proteins that many
protein bands did not get any results and do not match
with the any database. They also reported that few of the
identified proteins contains less than 3 peptide bands.
This indicates that the origin of these proteins is most
416
likely from un-sequenced microorganisms in activated
sludge. Based on their investigations, Park et al. (2008),
categorized extracellular proteins of activated sludge into
five different groups by virtue of their origin viz.,
enzyme associated with bacterial defense, cell
appendage, outer membrane proteins, intracellular
materials and influent sewage. They also reported that
the presence of a foreign protease might induce a
response from the native activated sludge
microorganisms.
Further research is warranted in the fields of
usage of biofilters in continuous flow systems. High
efficiency in terms of removal of pollutants has to be
identified and enumerated to production scale. The
genome types have to be evaluated for high efficient
417
stains. Further, new and novel filter materials capable
high elimination capacity of pollutants has to be
identified and modified accordingly for usage in the
treatment of domestic wastewater treatment.
418
Table 4: Evaluation of raw sewage for various physico-chemical parameters for
10 successive days
Parameter (all
values are
expressed in
ppm except pH,
EC, Temp. &
SVI)
Raw sewage value (No. of days)
1 2 3 4 5 6 7 8 9 10
pH 7.2 7.6 7.4 8.05 7.9 7.1 7.3 7.4 7.2 7.7
Electrical
conductivity
(mMhos/cm2)
2350 2330 2510 2420 2900 2760 2540 2800 2345 2300
Temperature
(°C) 29 28 25 24 22 24 25 24 28 27
TSS 360 400 410 380 375 350 380 400 360 395
VSS 140 168 163 145 160 170 150 113 135 170
Chlorides 143 155 125 179 162 201 172 184 176 152
Total Hardness 355 370 355 455 415 365 410 415 390 385
Alkalinity 510 530 535 525 400 415 485 423 532 514
C.O.D 460 510 550 520 480 490 500 520 470 470
B.O.D 192 215 220 218 198 200 150 135 110 140
Total Nitrogen
Ammonical N
Nitrate N
Nitrite N
Kjeldhal N
42.32
30.52
1.6
0.2
10
44.6
32.5
1.5
0.1
10.5
42.75
31
1.25
ND
10.5
49.2
35.6
1.5
0.1
12
48.2
35.5
1.6
0.1
11
42.0
30.5
1.0
ND
10.5
54.64
38.54
1.1
ND
15
54.35
39.0
1.25
0.1
14
54.5
38.1
1.3
0.1
15
56.1
40.1
1.0
ND
15
Total
Phosphorus
(as P)
8.5 8.40 6.37 5.92 6.68 9.0 8.6 6.75 6.0 9.5
Oil & grease 28 50.4 40.75 29 48 37.4 33 28.25 25.65 42.5
H2S 3.1 2.8 2.9 2.8 2.7 3.0 2.8 2.7 2.9 3.0
SVI (ml/g SS) 124 130 118 110 140 128 130 130 115 128
Table 5: Colony forming units produced by individual
microorganisms on nutrient agar medium after
adaptation to sterilized sewage.
S.No Organism C.F.U/ml
1 Bacillus megatherium 35 X 108
2 Nitrosomonas 42 X 108
3 Nitrobacter 45 X 108
4 Pseudomonas denitrificans 40 X 108
5 Chromatium sps., 38 X 108
6 Bacillus mucilaginosus 38 X 108
7 Lactobacillus acidophilus 28 X 108
8 Bacillus licheniformis 36 X 108
9 Rhodococcus terrae 32 X 108
10 Thiobacillus ferrooxidans -
420
Table 6: Effect of Bacillus megatherium and Nitrosomonas sps.,
as inoculum @ 1% in the domestic sewage treatment
S.
No
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Bacillus megatherium Nitrosomonas
Before
addition
of
culture
After
treatme
nt
time of
24
hours
Difference
between
before and
after
treatment
process in %
except pH,
temperature
& nitrite-
nitrogen
Before
addition
of
culture
After
treatmen
t
time of
24 hours
Difference
between
before and
after
treatment
process in
% except
pH,
temperature
& nitrite-
nitrogen
1 pH 7.6 7.6 - 7.8 7.7 0.1
2 E.C 2360 2470 4.66 2380 2390 0.42
3 Temperature 27 27.5 0.5°C 28 28 -
4 TSS 360 290 19.44 345 270 21.74
5 VSS 145 125 13.79 118 89 24.58
6 Chlorides 180 185 2.78 158 170 7.59
7 Hardness 370 385 4.05 410 376 8.29
8 Alkalinity 469 465 0.85 415 400 3.61
9 C O D 510 380 25.49 480 355 26.04
10 B O D 180 105 41.67 205 110 46.34
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
50.8
38.3
0.1
1.8
10.6
45.9
34.5
0.1
1.6
9.8
9.65
9.92
-
11.11
7.55
49.5
35.8
N.D
1.6
12.1
33.8
21.6
1.1
1.9
9.2
31.72
39.66
1.10
18.75
23.97
12 Phosphorus (as
P)
9.4 3.68 60.85 8.6 7.9 8.14
13 Oil & grease 33 32 3.03 29 29 -
14 H2 S 2.8 2.9 3.57 2.6 2.4 7.69
15 S V I 120 130 0.08 114 120 0.05
421
Table 7: Nitrobacter sps., and Pseudomonas denitrificans effect
as 1% inoculum in domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Nitrobacter sps., Pseudomonas denitrificans
Before
additio
n of
culture
After
treat
ment
time
of
24
hours
Difference
between
before and
after
treatment
process in
% except
pH,
temperature
& nitrite-
nitrogen
Before
addition
of
culture
After
treatm
ent
time of
24
hours
Difference
between
before and
after
treatment
process in %
except pH,
temperature
& nitrite-
nitrogen
1 pH 7.6 7.7 0.1 7.7 7.7 -
2 E.C 2540 2510 1.18 2300 2380 3.48
3 Temperature 27 28 1°C 27 27 -
4 TSS 380 260 31.58 312 243 22.12
5 VSS 154 115 25.32 128 94 26.56
6 Chlorides 177 130 26.55 162 149 8.02
7 Hardness 355 295 16.9 310 282 9.03
8 Alkalinity 390 372 4.62 419 395 5.73
9 C O D 530 395 25.47 460 325 29.35
10 B O D 210 123 41.43 194 110 43.3
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
50.2
38.2
0.1
1.1
10.8
34.7
22.8
0.6
2.1
9.2
30.88
40.31
500
90.91
14.81
48.65
34.6
0.05
1.7
12.3
32.1
21.2
0.1
1.9
8.9
34.02
38.73
100.00
11.76
27.64
12 Phosphorus (as P) 8.8 8.4 4.55 6.05 6.38 5.45
13 Oil & grease 34 33 2.94 28 28 -
14 H2 S 3.1 2.8 9.68 2.9 2.8 3.45
15 S V I 130 130 - 140 124 0.11
422
Table 8: 1% inoculum of Chromatium sps., and Bacillus
mucilaginosus effect in the treatment of domestic
sewage
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Chromatium sps., Bacillus mucilaginosus
Before
additio
n of
culture
After
treat
ment
time
of
24
hours
Difference
between
before and
after
treatment
process in %
except pH,
temperature
& nitrite-
nitrogen
Before
additio
n of
culture
After
treatmen
t
time of
24
hours
Difference
between
before and
after
treatment
process in
% except
pH,
temperatur
e & nitrite-
nitrogen
1 pH 7.8 7.7 0.1 7.9 8.0 0.1
2 E.C 2615 2620 0.19 2530 2580 1.98
3 Temperature 28 28 - 28 28.5 0.5°C
4 TSS 410 312 23.9 380 239 37.11
5 VSS 172 138 19.77 212 145 31.6
6 Chlorides 155 125 19.35 158 117 25.95
7 Hardness 355 340 4.23 410 370 9.76
8 Alkalinity 525 485 7.62 415 444 6.99
9 C O D 510 428 16.08 490 350 28.57
10 B O D 210 132 37.14 174 99 43.10
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
51.2
40.2
0.1
1.4
9.5
49.95
39.4
0.05
1.3
9.2
2.44
1.99
50
7.14
3.16
40.65
29.8
0.05
1.2
9.6
39.5
28.7
Not detected
1.3
9.5
2.83
3.69
-
8.33
1.04
12 Phosphorus (as
P)
7.2 7.1 1.39 9.4 8.1 13.83
13 Oil & grease 41 39 4.88 39 38 2.56
14 H2 S 3.2 2.1 34.38 2.9 2.7 6.90
15 S V I 120 110 0.08 130 120 0.76
423
Table 9: Lactobacillus acidophilus and Bacillus licheniformis
effect in the treatment of domestic sewage
S.
N
o
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Lactobacillus acidophilus Bacillus licheniformis
Before
addition
of
culture
After
treatme
nt
time of
24
hours
Difference
between
before and
after
treatment
process in
% except
pH,
temperatu
re &
nitrite-
nitrogen
Before
additio
n of
culture
After
treatm
ent
time of
24
hours
Difference
between
before and
after
treatment
process in
% except
pH,
temperatu
re &
nitrite-
nitrogen
1 pH 7.6 7.5 0.1 8.1 8.2 0.1
2 E.C 2430 2450 0.82 2430 2420 0.41
3 Temperature 27.5 27.5 - 27 27 -
4 TSS 360 295 18.06 390 318 18.46
5 VSS 125 94 24.8 155 149 3.87
6 Chlorides 178 139 21.91 160 146 8.75
7 Hardness 395 385 2.53 375 360 4.0
8 Alkalinity 423 410 3.07 440 435 1.14
9 C O D 468 372 20.51 485 415 14.43
10 B O D 145 96 33.79 195 124 36.41
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
47.7
36.2
not detected
0.9
10.6
47.4
35.6
not detected
1.1
10.7
0.63
1.66
-
22.22
0.94
42.2
32.6
not
detected
1.1
8.5
40.25
30.8
0.05
1.2
8.2
4.62
5.52
-
9.09
3.53
12 Phosphorus (as
P)
10.5 10.4 0.95 8.1 8 1.23
13 Oil & grease 51 49 3.92 44 42 4.55
14 H2 S 2.9 2.85 1.72 2.6 2.5 3.85
15 S V I 130 140 0.76 120 108 0.1
424
Table 10: Effect of Rhodobacter terrae and Thiobacillus
ferrooxidans in domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Rhodobacter terrae Thiobacillus ferrooxidans
Before
addition
of
culture
After
treatme
nt
time of
24
hours
Difference
between
before and
after
treatment
process in
% except
pH,
temperature
& nitrite-
nitrogen
Before
addition
of
culture
After
treatm
ent
time of
24
hours
Difference
between
before and
after
treatment
process in
% except
pH,
temperature
& nitrite-
nitrogen
1 pH 7.8 7.8 - 7.3 7.1 0.2
2 E.C 2470 2462 0.32 2580 2570 0.39
3 Temperature 27 27.5 0.5°C 27 27 -
4 TSS 348 295 15.23 380 360 5.26
5 VSS 170 105 38.24 136 130 4.41
6 Chlorides 177 155 12.43 165 160 3.03
7 Hardness 395 396 0.25 400 405 1.25
8 Alkalinity 415 422 1.69 469 473 0.85
9 C O D 451 399 11.53 498 499 0.20
10 B O D 184 132 28.26 172 181 5.23
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
53.5
39.2
0.1
1.4
12.8
53.2
38.4
not detected
1.6
13.2
0.56
2.04
-
14.29
3.12
41.26
29.2
0.06
1
11
41.5
28.9
0.06
1.1
11.5
0.58
1.03
-
10
4.55
12 Phosphorus (as
P)
11 10.8 1.82 10.8 10.85 0.46
13 Oil & grease 33 33 - 38 38 -
14 H2 S 2.2 2.9 31.82 1.9 1.9 -
15 S V I 120 120 - 120 120 -
425
Table 11: % of consortium effect in domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Inoculum @ 0.05% Inoculum @ 0.1%
Befor
e
treat
ment
Blank After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.8 7.8 7.7 - 7.9 7.9 7.9 -
2 E.C 1992 1998 2009.33 0.87 2460 2450 2380 3.25
3 Temperature 28 28 28 - 28 28 28 -
4 TSS 318 316 141.66 55.45 343 339 141 58.89
5 VSS 135 136 68 49.63 161 160 72.67 54.87
6 Chlorides 155 152 79.66 48.61 172 175 89 48.26
7 Hardness 290 295 195 32.76 315 316 111 64.76
8 Alkalinity
402 410 277.67 30.93
432 429 279.3
3 35.34
9 C O D
480 473 210 56.25
465 459 190.3
3
59.07
10 B O D 218 216 95.67 56.12 215 213 82.67 61.55
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
53.25
41.8
0.05
1.6
9.8
54.9
43.2
ND
1.6
9.1
31.6
22.13
0.1
1.47
7.9
40.66
47.05
100.0
8.33
19.39
48.3
34.6
ND
1.4
12.3
49.6
5
36.5
0.05
1.5
11.6
28.42
17.13
0.05
1.5
9.73
41.17
50.48
-
7.14
20.87
12
Phosphorus (as
P) 10.8 10.8 5.6 48.15 9.6 9.5 4.7
51.04
13 Oil & grease 41 40 40 2.44 38 38 37 2.63
14 H2 S 3.1 3.15 1.9 38.71 2.9 3 1.6 44.83
15 S V I 115 118 90 21.74 120 126 92 23.33
426
Table 12: Effect of 0.2 % and 0.3 % consortium in domestic
sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Inoculum @ 0.2% Inoculum @ 0.3%
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatm
ent
Blank After
treatme
nt
(Mean)
%
Remova
l
(except
pH &
temp.)
1 pH 8.2 8.2 8.2 - 7.9 7.8 8 0.1
2 E.C
2050 2060 2040.3
3
0.47 1680 1630 1480 11.9
3 Temperature 28.5 28 28 0.5°C 27 28 28 1.0°C
4 TSS 370 375 143.67 61.17 410 405 152 62.93
5 VSS 115 114 27.33 50.14 125 130 60.33 51.73
6 Chlorides 148 152 76 48.65 169 161 90 46.75
7 Hardness 395 390 233.67 40.84 400 410 232.67 41.83
8 Alkalinity 525 524 311 40.76 480 475 291.67 39.24
9 C O D 455 455 164 63.96 460 460 160 65.22
10 B O D 198 197 71.67 63.8 210 215 74.67 64.44
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
51.4
40.1
0.05
1.5
9.75
52.2
40.9
ND
1.5
9.8
24.43
19.3
0.1
0.6
4.43
52.46
51.87
100.0
60.0
54.53
41.26
29.4
0.06
0.9
10.9
41.75
30.2
0.05
1.0
10.5
19.02
13.5
0.05
1.0
4.47
53.9
54.08
11.11
11.11
59.02
12 Phosphorus (as P) 11.2 11.3 4.67 58.33 9.8 9.7 4.23 56.8
13 Oil & grease 33 33 31.67 4.04 38 38 36.33 4.39
14 H2 S 3.2 3.2 1.3 59.38 2.9 2.9 1.15 60.34
15 S V I 115 118 91 20.87 130 130 99 23.85
427
Table 13: Effect of 0.4 % and 0.5% consortium in domestic
sewage treatment
S.
N
o
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Inoculum @ 0.4% Inoculum @ 0.5%
Before
treatm
ent
Blank After
treatme
nt
(Mean)
%
Removal
(except
pH &
temp.)
Befor
e
treat
ment
Blank After
treat
ment
(Mea
n)
%
Removal
(except
pH &
temp.)
1 pH 7.8 7.8 7.67 0.13 7.9 7.8 7.8 0.1
2 E.C 1690 1610 1318 22.01 1880 1890 1610 14.36
3 Temperature 28 27 27 1.0°C 27 27 27 -
4 TSS
348 335 126 63.79 312 310 111.6
7 64.21
5 VSS 132 130 54.33 58.84 127 126 48 62.20
6 Chlorides 190 185 99.67 47.54 168 170 89.67 46.63
7 Hardness
335 340 218 34.93 315 340 234.6
7 25.50
8 Alkalinity
420 425 253.33 39.68 425 420 258.3
3 39.22
9 C O D
435 415 151.33 65.21 448 451 143.6
7 67.93
10 B O D 195 195 68 65.13 198 199 67 66.16
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
40.96
29.4
0.06
1.0
10.5
42.1
31.4
ND
1.0
10.7
18.73
13.97
0.1
0.77
3.9
54.26
52.49
66.67
23.33
62.86
48.85
34.8
0.05
1.6
12.4
50.6
34.6
0.1
1.5
12.3
21.03
15.77
0.10
1.03
4.13
56.64
54.69
100.0
35.42
66.67
12 Phosphorus (as
P) 9.8 9.9 3.95
59.69 10.4 10.6 4.03 61.22
13 Oil & grease 32 33 31 3.13 36 36 34 5.56
14 H2 S 2.7 2.8 0.97 64.20 2.9 3 0.93 67.82
15 S V I 128 132 99 22.66 124 130 96 22.58
428
Table 14: 4 hours and 8 hours HRT effect in domestic sewage
treatment with 0.2% consortium
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
HRT @ 4 hours HRT @ 8 hours
Before
treatme
nt
Blank After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatm
ent
Blank After
treatm
ent
(Mean)
%
Remova
l
(except
pH &
temp.)
1 pH 8.2 8.2 8.2 - 7.8 7.8 7.9 0.1
2 E.C 2390 2340 2150 10.04 2490 2495 2003.3 19.54
3 Temperature 27 27 27 - 28 27.5 27.5 0.5°C
4 TSS 395 389 274.33 30.55 405 405 209.67 48.23
5 VSS 158 156 118.67 24.89 169 170 98 42.01
6 Chlorides 162 171 126 22.22 183 181 113.33 38.07
7 Hardness 390 395 317 18.72 339 344 265.33 21.73
8 Alkalinity 415 421 341.33 17.75 495 489 373 24.65
9 C O D 492 495 319.67 35.03 510 505 265.67 47.91
10 B O D 218 215 148 32.11 219 206 117.33 46.42
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
42.5
32.4
ND
1.1
9.0
44.85
34.1
0.05
1.5
9.2
31.95
24.13
0.05
1.0
6.77
24.82
25.51
-
9.09
24.81
51.35
40.4
0.05
1.3
9.6
54.85
43.1
0.05
0.9
10.8
35.77
28.17
0.07
1.40
6.13
30.35
30.28
33.33
7.69
36.11
12 Phosphorus (as
P) 9.2 9.3 6.5 29.35 8.2 8.4 5.23 36.18
13 Oil & grease 38 38 38 - 42 42 42 -
14 H2 S 2.8 2.9 2.1 25 2.9 2.95 1.97 32.18
15 S V I 136 140 106 22.06 130 132 104 20.0
429
Table 15: 12 hours and 16 hours HRT effect in domestic sewage
treatment with 0.2% consortium
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
HRT @ 12 hours HRT @ 16 hours
Before
treatme
nt
Blank After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.7 0.1 7.8 7.8 7.9 0.1
2 E.C 2380 2380 2166.6 8.96 2430 2440 2185 10.08
3 Temperature 28 28 28 - 28 28 28 -
4 TSS 365 366 150 58.90 372 365 145.33 60.93
5 VSS 146 140 73 50.0 128 125 56.67 55.73
6 Chlorides 171 172 78.67 54.0 162 162 68 58.02
7 Hardness 390 405 272.67 30.09 395 405 256.67 35.02
8 Alkalinity 453 450 271 40.18 424 430 235 44.58
9 C O D 508 510 190.67 62.47 478 480 174.67 63.46
10 B O D 184 185 72 60.87 204 202 77 62.25
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
51.3
39.1
0.1
1.4
10.7
52.7
40.2
0.1
1.5
10.9
27.10
19.97
0.1
1.6
5.43
47.13
48.93
-
14.29
49.22
48.85
35.8
0.05
1.1
11.9
51.25
38.1
0.05
1.0
12.1
23.42
16.8
0.08
1.2
5.33
52.06
53.07
66.67
9.09
55.18
12 Phosphorus (as
P) 9.6 9.6 4.6
52.08 8.9 9 3.95 55.62
13 Oil & grease 38 38 36 5.26 31 30 29 6.45
14 H2 S 2.9 2.95 1.3 55.17 3.0 3.0 1.3 56.67
15 S V I 130 132 102 21.54 122 120 95 22.13
430
Table 16: Effect of 20 hours and 24 hours HRT with 0.2%
consortium in domestic sewage treatment
S.
No
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
HRT @ 20 hours HRT @ 24 hours
Before
treatme
nt
Blank After
treat
ment
(Mean
)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blank After
treat
ment
(Mea
n)
%
Removal
(except
pH &
temp.)
1 pH 7.6 7.6 7.7 0.1 7.5 7.6 7.6 0.1
2 E.C
1980 1960 1740 12.12
2540 2520 2246.
6 11.55
3 Temperature 27.5 27 28 0.5°C 27 27 27 -
4 TSS
350 355 133.67 61.81
390 385 148.3
3 61.97
5 VSS 128 125 53 58.59 145 148 59.17 59.20
6 Chlorides 182 180 74.33 59.16 172 175 72 58.14
7 Hardness 398 395 238.67 40.03 410 405 242 40.98
8 Alkalinity 430 430 210.67 51.01 470 465 234 50.21
9 C O D
475 477 172.67 63.65
520 515 187.1
7 64.01
10 B O D 155 154 56 63.87 205 202 74 63.9
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
46.6
36.3
ND
0.5
9.8
48.72
35.1
0.02
0.7
9.9
20.79
15.93
0.06
0.87
3.93
55.39
56.11
-
73.33
59.86
42.65
30.6
0.05
1.1
10.9
44.35
32.1
0.05
1.2
11.0
18.92
13.17
0.09
1.27
4.4
55.64
56.97
73.33
15.15
59.63
12 Phosphorus (as
P) 10.2 10.3 4.1 59.8 10.6 10.7 4.13
61.01
13 Oil & grease 48 48 45 6.25 38 37 35 7.89
14 H2 S 2.9 2.9 1.1 62.07 2.1 2.1 0.75 64.29
15 S V I 120 118 87 27.5 130 132 88 32.31
431
Table 17: Effect of stones as biofilter material in 10% and 20%
volumes along with 0.2% consortium and 12 hours
HRT in domestic sewage treatment
S.
No
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Volume – 10 % Volume – 20 %
Before
treatme
nt
Blank After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Removal
(except
pH &
temp.)
1 pH 7.8 7.8 7.8 - 7.7 7.7 7.7 -
2 E.C 2160 2170 2076.6 3.86 2010 2020 1923.3 4.31
3 Temperature 28 28 28 - 28 28 28 -
4 TSS 360 365 140.67 60.93 360 348 145 59.72
5 VSS 125 128 56 55.2 126 128 55 56.35
6 Chlorides 168 170 70.33 58.13 176 180 74 57.95
7 Hardness 385 390 247.3 35.76 390 385 250 35.9
8 Alkalinity
405 404 219 45.93
415 421 235.6
7 43.21
9 C O D 460 462 171 62.83 480 482 177 63.13
10 B O D 206 209 78 62.14 185 190 79 57.3
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
45.95
34.2
0.05
0.9
10.8
48.15
36.3
0.05
0.9
10.9
21.55
15.67
0.05
1.0
4.83
53.1
54.19
-
11.11
55.25
46.84
36.4
0.04
0.6
9.8
47.44
37.1
0.04
0.5
9.8
21.72
16.67
0.05
0.6
4.4
53.64
54.21
25.0
-
55.10
12 Phosphorus (as
P) 9.6 9.6 4.23
55.9 9.9 9.9 4.1
58.59
13 Oil & grease 34 34 34 - 44 44 44 -
14 H2 S 2.8 2.9 1.2 57.14 2.8 2.9 1.2 57.14
15 S V I 118 116 87 26.27 124 127 90 27.42
432
Table 18: 30% volume and 40 % volume of stones as biofilter
material effect along with 0.2% consortium and 12
hours HRT effect in domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Volume – 30 % Volume – 40 %
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remo
val
(exce
pt pH
&
temp.
)
Before
treatm
ent
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.7 0.1 7.7 7.7 7.6 0.1
2 E.C 2240 2190 2043.3 8.78 2320 2310 2210 4.74
3 Temperature 28 28 28 - 28 28 28 -
4 TSS 345 344 139 59.71 340 345 139 59.12
5 VSS 128 124 56 56.25 118 116 50 57.63
6 Chlorides 154 157 65 57.79 145 144 62 57.24
7 Hardness 390 390 250 35.9 380 390 243 36.05
8 Alkalinity
470 473 263.6
7
43.9 460 465 258 43.91
9 C O D 510 509 190 62.75 480 475 177 63.13
10 B O D 202 203 77 61.88 206 208 78 62.14
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
43.25
31.7
0.05
1.1
10.4
43.65
32.1
0.05
1.1
10.4
20.42
14.57
0.05
1.2
4.6
52.79
54.05
-
9.09
55.77
44.25
33.4
0.05
1.0
9.8
45.55
34.6
0.05
1.0
9.9
20.6
15.37
0.06
1.1
4.4
53.45
53.99
26.67
10.0
55.10
12 Phosphorus (as P) 10.4 10.5 4.4 57.69 8.6 8.7 3.7 56.98
13 Oil & grease 40 40 40 - 38 38 38 -
14 H2 S 2.6 2.7 1.1 57.69 2.6 2.7 1.1 57.69
15 S V I 130 132 94 27.69 134 135 96 28.36
433
Table 19: Effect of 8 hours HRT, 9 HRT with 10% volume of
granite stones and 0.2% consortium in domestic
sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature & SVI)
HRT @ 8 hours HRT @ 9 hours
Befor
e
treat
ment
Blank After
treatm
ent
(Mean)
%
Removal
(except
pH &
temp.)
Before
treatm
ent
Blan
k
Afte
r
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.8 7.8 7.8 - 7.6 7.6 7.5 0.1
2 E.C
2090 2090 1870 10.53 2130 2140 1943
.3 8.76
3 Temperature 27 27.5 27.5 0.5°C 28 28 28 -
4 TSS
340 355 177.33 47.84 380 385 186.
33 50.96
5 VSS
120 112 70 41.67 145 140 82.3
3 43.22
6 Chlorides 172 174 105 38.95 185 188 105 43.24
7 Hardness 380 370 295.33 22.28 345 340 261 24.35
8 Alkalinity
410 415 307 25.12
390 385 276.
67 29.06
9 C O D 460 465 244.67 46.81 430 432 213 50.47
10 B O D 210 212 113 46.19 192 194 99 48.44
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
42.25
313
0.05
1.0
9.9
43.45
32.4
0.05
1.0
10
29.67
22.13
0.04
1.1
6.4
29.77
29.29
20.0
10.0
35.35
43.6
34.2
ND
0.8
8.6
45.01
35.4
0.01
0.8
8.8
28.32
22.13
0.05
0.93
5.2
35.05
35.28
-
16.67
39.53
12 Phosphorus (as P) 10.5 10.5 6.8 35.24 9.8 9.8 6.03 38.44
13 Oil & grease 38 37 37 2.63 42 43 42 -
14 H2 S 2.6 2.7 1.8 30.77 2.7 2.8 1.82 32.72
15 S V I 128 130 90 29.69 132 132 90 29.69
434
Table 20: 10 hours HRT and 11 hours HRT effect with 10%
volume of granite stones and 0.2% consortium in
domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
HRT @ 10 hours HRT @ 11 hours
Befor
e
treat
ment
Blank After
treatm
ent
(Mean)
%
Remova
l
(except
pH &
temp.)
Befor
e
treat
ment
Blank After
treatm
ent
(Mean)
%
Remova
l
(except
pH &
temp.)
1 pH 7.7 7.7 7.6 0.1 7.7 7.7 7.7 -
2 E.C 1890 1860 1713.3 9.35 1920 1930 1748.6 8.92
3 Temperature 28 27 27 1°C 28 28 28 -
4 TSS 390 392 179.33 54.02 355 360 153 56.9
5 VSS 145 140 78 46.21 140 138 80.33 42.62
6 Chlorides 160 162 85 46.88 174 175 87.33 49.81
7 Hardness 390 380 288.33 26.07 360 352 260.33 27.69
8 Alkalinity 430 410 290.33 32.48 435 430 278 36.09
9 C O D 485 480 220 54.64 490 492 198.67 59.46
10 B O D 202 203 97 51.98 198 200 91 54.04
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
47.95
38.2
0.05
1.1
8.6
49.35
39.4
0.05
1.2
8.7
29.27
23.03
0.07
1.27
4.9
38.96
39.7
33.33
15.15
43.02
45.25
36.4
0.05
1.0
7.8
47.06
38.1
0.06
1.0
7.9
25.62
20.40
0.05
1.03
4.13
43.39
43.96
-
3.33
47.01
12 Phosphorus (as
P) 9.7 9.7 5.37
44.67 9.6 9.6 5
47.92
13 Oil & grease 42 41 41 2.38 38 37 37 2.63
14 H2 S 2.7 2.8 1.6 40.74 2.4 2.6 1.27 47.22
15 S V I 124 128 88 29.03 130 132 90 30.77
435
Table 21: 12 hours HRT effect with 10% volume of granite
stones and 0.2% consortium in domestic sewage
treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
HRT @ 12hours
Before
treatment
Blank After
treatment
(Mean)
% Removal
(except pH
& temp.)
1 pH 7.7 7.7 7.7 -
2 E.C 2240 2260 2023.3 9.67
3 Temperature 27 27 27 -
4 TSS 360 364 147 59.17
5 VSS 138 130 67 51.45
6 Chlorides 182 176 84.33 53.66
7 Hardness 398 400 280 29.65
8 Alkalinity 460 465 275.67 40.07
9 C O D 490 493 180.67 63.13
10 B O D 192 194 75 60.94
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
47.45
36.7
0.05
1.1
9.6
48.87
38.1
0.07
1.0
9.7
24.69
18.67
0.05
1.2
4.77
47.97
49.14
6.67
9.09
50.35
12 Phosphorus (as P) 10.2 10.3 4.8 52.94
13 Oil & grease 36 36 36 -
14 H2 S 2.8 2.9 1.23 55.95
15 S V I 140 138 94 32.86
436
Table 22: Time period of 10 days and 20 days effect in
sewage treatment along with 10% volume of
granite stones, 0.2% consortium and 12 hours HRT
S.
N
o
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 10 days Time period – 20 days
Befo
re
treat
men
t
Blank After
treatm
ent
(Mean)
%
Removal
(except
pH &
temp.)
Befor
e
treat
ment
Blank After
treat
ment
(Mea
n)
%
Removal
(except
pH &
temp.)
1 pH 7.7 7.7 7.6 0.1 8.1 8.1 8.2 0.1
2 E.C 1690 1690 1521.6 9.96 1930 1910 1646.6 14.68
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 320 322 130 59.38 375 379 154 58.93
5 VSS 116 112 57 50.86 140 138 69.67 50.24
6 Chlorides 138 142 63 54.35 178 176 82 53.93
7 Hardness 330 338 227.33 31.11 338 341 236 30.18
8 Alkalinity 380 390 228 40.0 385 390 230 40.26
9 C O D 410 415 154 62.44 425 428 160 62.35
10 B O D 158 159 61 61.39 188 189 73.3 60.99
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
40.9
30.8
ND
0.9
9.2
41.82
31.6
0.02
1.0
9.2
21.43
15.67
0.06
1.0
4.7
47.61
49.13
-
11.11
48.91
44.25
34.2
0.05
0.9
9.1
45.95
35.8
0.05
0.9
9.2
23.21
17.5
0.11
1.1
4.5
47.56
48.83
113.33
22.22
50.55
12 Phosphorus (as
P) 8.9 8.9 4.27
52.06 9.6 9.6 4.6 52.08
13 Oil & grease 32 32 32 - 38 37 37 2.63
14 H2 S 2.4 2.5 1.1 54.17 2.6 2.8 1.1 57.69
15 S V I 125 128 90 28.0 120 124 88 26.67
437
Table 23: Effect of 30 days time period and 40 days time
period in sewage treatment along with 10% volume
of stones, 0.2% consortium and 12 hours HRT
S.
No
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 30 days Time period – 40 days
Before
treatm
ent
Blan
k
After
treat
ment
(Mea
n)
%
Removal
(except
pH &
temp.)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.6 7.6 7.6 - 7.7 7.7 7.6 0.1
2 E.C 1860 1850 1583.
3 14.87 1890 1850 1523.3
19.4
3 Temperature 28 27 27 1°C 27.5 27 27 0.5°C
4 TSS 385 380 157 59.22 360 355 147 59.17
5 VSS 142 140 70.33 50.47 144 140 70.33 51.16
6 Chlorides 168 165 77 54.17 158 160 72 54.43
7 Hardness 395 400 272.6 30.97 370 375 251.33 32.07
8 Alkalinity 415 420 249.6 39.84 440 445 259.67 40.98
9 C O D 430 432 159 63.02 490 485 175.67 64.15
10 B O D 190 195 72 62.11 196 198 75 61.73
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
47.3
32.4
ND
1.0
7.9
43.25
34.1
0.05
1.2
7.9
22.07
16.5
0.1
1.53
3.93
46.57
49.07
-
53.33
50.21
43.45
34.3
0.05
1.0
8.1
44.96
35.8
0.06
1.1
8.0
22.87
17.13
0.1
1.57
4.07
47.37
50.05
100.0
56.67
49.79
12 Phosphorus (as
P) 8.8 8.8 4.2 52.27 9.4 9.4 4.4
53.19
13 Oil & grease 38 38 38 - 38 38 38 -
14 H2 S 2.5 2.6 1.1 56.0 2.6 2.6 1.1 57.69
15 S V I 140 140 90 35.71 144 144 90 37.50
438
Table 24: 50 days time period and 60 days time period effect
in sewage treatment along with 10% volume of
stones, 0.2% consortium and 12 hours HRT
S.
N
o
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 50 days Time period – 60 days
Before
treatm
ent
Blank After
treatm
ent
(Mean
)
%
Removal
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.7 7.7 7.6 0.1 7.8 7.8 7.7 0.1
2 E.C 2140 2100 1693.3 20.87 1990 1980 1595 19.85
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 380 375 154 59.47 370 360 150 59.46
5 VSS 148 141 71.67 51.58 144 140 69.33 51.85
6 Chlorides 176 178 79 55.11 172 174 77 55.23
7 Hardness 390 385 264.67 32.14 380 390 258 32.11
8 Alkalinity 450 460 260.67 42.07 460 450 267 41.96
9 C O D 510 512 183 64.12 510 505 182.67 64.18
10 B O D 218 216 82.67 62.08 212 210 80.33 62.11
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
49.69
38.2
0.09
1.6
9.8
51.3
39.8
0.1
1.6
9.8
25.7
19.0
0.13
1.7
4.87
48.28
50.26
48.15
6.25
50.34
47.2
36.8
0.1
1.4
8.9
48.3
37.9
0.1
1.4
8.9
24.38
18.33
0.15
1.53
4.4
48.35
50.18
46.67
9.52
50.56
12 Phosphorus (as
P) 10.4 10.5 4.9 52.88 9.8 9.8 4.53 53.74
13 Oil & grease 34 33 33 2.94 38 37 37 2.63
14 H2 S 2.8 2.8 1.2 57.14 2.8 2.9 1.2 57.14
15 S V I 132 130 88 33.33 124 128 80 35.48
439
Table 25: Effect of clay balls as biofilter material in 10% and
20% volumes along with 0.2% consortium and 12
hours HRT in domestic sewage treatment
S.
N
o
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Volume – 10% Volume – 20%
Before
treatme
nt
Blank After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Befor
e
treat
ment
Blank After
treat
ment
(Mean
)
%
Remova
l
(except
pH &
temp.)
1 pH 7.8 7.8 7.87 0.07 8 8 8.03 0.03
2 E.C 2240 2210 1783.3 20.39 2360 2280 1893.3 19.77
3 Temperature 28 28 28 - 27 28 28 1°C
4 TSS 340 345 132 61.18 390 395 132.67 65.98
5 VSS 116 110 57 50.86 158 150 73 53.8
6 Chlorides 162 164 70 56.79 172 178 67.33 60.85
7 Hardness 395 390 245 37.97 370 360 206.67 44.14
8 Alkalinity 410 415 216.33 47.24 445 450 209.33 52.96
9 C O D 490 494 164 66.53 490 494 152 68.98
10 B O D 209 212 75 64.11 202 208 65 67.82
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
47.7
34.8
ND
1.1
11.8
48.6
35.6
ND
1.1
11.9
22.84
16.13
0.04
1.57
5.1
52.12
53.64
-
42.42
56.78
41.73
31.6
0.03
1.2
8.9
42.94
32.8
0.04
1.2
8.9
17.09
12.03
0.09
1.67
3.3
59.05
61.92
188.89
38.89
62.92
12 Phosphorus (as
P) 8.6 8.7 3.87
55.04 9.1 9.2 3.5 61.54
13 Oil & grease 28 28 28 - 38 38 38 -
14 H2 S 2.5 2.7 1.0 60.0 2.6 2.7 0.97 62.82
15 S V I 120 122 86 28.33 130 132 90 30.77
440
Table 26: 30% volume and 40 % volume of clay balls effect as
biofilter material along with 0.2% consortium and
12 hours HRT for domestic sewage treatment
S.
No
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Volume – 30% Volume – 40%
Befo
re
treat
ment
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatm
ent
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.7 0.1 7.9 8 7.97 0.07
2 E.C 2330 2290 1843.3 20.89 2420 2410 1910 21.07
3 Temperature 27.5 28 28 0.5°C 28 28 28 -
4 TSS 380 384 110 71.05 340 348 93.5 72.5
5 VSS 128 120 56 56.25 184 174 81 55.98
6 Chlorides 166 164 54 67.47 168 166 52 69.05
7 Hardness 390 380 199 48.97 395 390 193.67 50.97
8 Alkalinity 421 420 177 57.96 430 430 167.67 61.01
9 C O D 482 488 131 72.82 490 490 130 73.47
10 B O D 153 154 43.17 71.79 192 194 53.67 72.05
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
46.55
35.2
0.05
1.1
10.2
48.35
36.8
0.05
1.2
10.3
17.63
12.4
0.1
1.6
3.53
62.13
64.77
93.33
45.45
65.36
42.15
31.2
0.05
1.1
9.8
44.25
33.1
0.05
1.2
9.9
15.63
10.63
0.09
1.7
3.2
62.93
65.92
86.67
54.55
67.35
12 Phosphorus (as
P) 9.8 9.8 3.3 66.33 9.6 9.6 3.1 67.71
13 Oil & grease 48 48 47 2.08 38 37 37 2.63
14 H2 S 2.8 2.9 0.9 67.86 2.8 2.8 0.87 69.05
15 S V I 125 128 86 31.20 130 132 86 33.85
441
Table 27: 8 hours HRT and 9 hours HRT effect in domestic
sewage treatment in the presence of 30% volume of
clay balls and 0.2% consortium
S.
No
Physico-
chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
HRT@ 8 hours HRT @ 9hours
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean)
%
Removal
(except pH
& temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.7 0.1 7.8 7.8 7.8 -
2 E.C 2320 2300 1996.6 13.94 2690 2420 2116.6 14.99
3 Temperature 27 27 27 - 28 28 28 -
4 TSS 324 328 132.33 59.16 384 390 140 63.54
5 VSS 132 130 60 54.55 170 162 80 52.94
6 Chlorides 158 160 72 54.43 160 160 67.33 57.92
7 Hardness 304 309 203.67 33.0 360 355 223.33 37.96
8 Alkalinity 424 420 249 41.27 520 520 280.33 46.09
9 C O D 486 488 190 60.91 480 484 172.67 64.03
10 B O D 194 190 77 60.31 190 196 65.83 65.35
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal
Nitrogen
47.54
34.8
0.04
1.3
11.4
48.5
35.9
0.05
1.3
11.6
24.05
16.7
0.08
1.53
5.73
49.41
52.01
108.33
17.95
49.71
45.0
34.6
0.08
1.12
9.2
46.69
36.1
0.09
1.1
9.4
21.51
15.53
0.11
1.57
4.3
52.19
55.11
41.67
39.88
53.26
12 Phosphorus (as
P) 7.8 7.8 3.6 53.85 7.9 8.1 3.4 56.96
13 Oil & grease 32 32 32 - 38 39 38 -
14 H2 S 2.7 2.8 1.2 55.56 2.9 2.9 1.13 60.92
15 S V I 122 120 90 26.23 128 130 90 29.69
442
Table 28: 10 hours HRT and 11 hours HRT effect in domestic
sewage treatment along with 30% volume of clay
balls and 0.2% consortium
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT@ 10 hours HRT @ 11 hours
Befo
re
treat
men
t
Blank After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.8 7.8 7.9 0.1 7.4 7.5 7.6 0.2
2 E.C
1960 1910 1603.3 18.2
1680 1620 1366.
6 18.65
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 348 345 108 68.97 380 375 112 70.53
5 VSS 172 170 78 54.65 142 138 63.33 55.4
6 Chlorides 178 175 50.33 71.72 168 169 59 64.88
7 Hardness 396 400 221.6 44.02 400 400 218 45.5
8 Alkalinity 418 415 193 53.83 480 460 207 56.88
9 C O D 460 465 137.67 70.07 498 502 147 70.48
10 B O D 184 186 56 69.57 184 190 55.33 69.93
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
53.3
39.2
0.01
1.1
12.9
54.9
40.6
0.01
1.1
13.1
21.36
14.97
0.04
1.4
4.93
59.93
61.82
333.33
27.27
61.76
43.66
31.6
0.06
1.2
10.8
45.16
32.9
0.06
1.3
10.9
17.22
11.77
0.05
1.47
3.93
60.57
62.76
16.67
22.22
63.58
12 Phosphorus (as P) 10.8 10.7 4.0 62.96 9.6 9.8 3.43 64.24
13 Oil & grease 36 36 36 - 38 38 38 -
14 H2 S 2.4 2.5 0.9 62.5 2.6 2.7 0.9 65.38
15 S V I 116 118 80 31.03 110 112 78 29.09
443
Table 29: 12 hours HRT effect in presence of 30% volume of
clay balls and 0.2% consortium for domestic
sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
HRT@ 12 hours
Before
treatment
Blank After
treatment
(Mean)
%
Removal
(except pH
& temp.)
1 pH 7.8 7.8 7.87 0.1
2 E.C 1980 1930 1560 21.21
3 Temperature 27 28 28 1°C
4 TSS 318 319 93 70.75
5 VSS 134 130 59 55.97
6 Chlorides 156 160 51.33 67.09
7 Hardness 280 284 143 48.93
8 Alkalinity 390 390 136.67 58.03
9 C O D 380 390 103.67 72.72
10 B O D 194 198 56 71.13
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
51.98
40.7
0.08
1.4
9.8
53.28
52.1
0.08
1.5
9.9
19.83
14.63
0.1
1.63
3.43
61.84
64.05
25.0
16.67
64.97
12 Phosphorus (as P) 10.4 10.3 3.53 66.03
13 Oil & grease 42 42 42 -
14 H2 S 3.1 3.1 1.0 67.74
15 S V I 120 120 80 33.33
444
Table 30: Time period of 10 days and 20 days effect in domestic
sewage treatment along with 30% volume of clay
balls, 0.2% consortium and 10 hours HRT
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 10 days Time period – 20 days
Before
treatm
ent
Blank After
treatme
nt
(Mean)
%
Remova
l
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Removal
(except
pH &
temp.)
1 pH 8.1 8.1 8.1 - 7.9 7.9 8 0.1
2 E.C 1960 1920 1590 18.88 1790 1750 1450 18.99
3 Temperature 28 28 28 - 27 28 28 1°C
4 TSS 380 375 114.33 69.91 390 395 113 71.03
5 VSS 116 110 51 56.03 128 120 53.67 58.07
6 Chlorides 148 152 45.67 69.14 172 178 52 69.77
7 Hardness
390 380 214.67 44.96 400 410 210.6
7 47.33
8 Alkalinity 525 520 236 55.05 480 470 211 56.04
9 C O D 460 470 133 71.09 480 490 134 72.08
10 B O D 198 199 57.33 71.04 210 209 59 71.90
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
50.45
39.2
0.05
1.4
9.8
51.25
39.8
0.05
1.5
9.9
20.0
14.53
0.1
1.77
3.6
60.36
62.93
93.33
26.19
63.27
42.26
31.4
0.06
0.9
9.9
43.86
33.1
0.06
0.9
9.8
16.39
11.3
0.1
1.6
3.37
61.22
64.01
66.67
77.78
65.99
12 Phosphorus (as P) 10.6 10.2 3.83 63.84 8.9 9.1 3.03 65.92
13 Oil & grease 32 32 31 3.13 36 36 35 2.78
14 H2 S 3.0 3.0 1.1 63.33 2.8 2.9 0.97 65.48
15 S V I 130 132 90 30.77 125 125 86 31.20
445
Table 31: 30days and 40 days time period effect along with 30%
volume of clay balls, 0.2% consortium and 10 hours
HRT for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 30 days Time period – 40 days
Befor
e
treat
ment
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatm
ent
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.7 7.7 7.87 0.17 7.8 7.8 7.87 0.08
2 E.C 1690 1620 1360 19.53 1910 1900 1530 19.90
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 348 345 99.33 71.46 324 328 94 70.99
5 VSS 136 130 56.67 58.33 128 120 54 57.81
6 Chlorides 184 184 55 70.11 168 168 51.67 69.25
7 Hardness 320 326 160 50.0 328 320 160.6
7 51.02
8 Alkalinity 410 415 176 57.07 418 415 178 57.42
9 C O D 460 460 125.67 72.68 448 456 145 67.63
10 B O D 192 198 52 72.92 198 202 62.67 68.35
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
41.26
29.6
0.06
1.2
10.4
43.16
31.3
0.06
1.3
10.5
15.63
10.37
0.1
1.67
3.5
62.11
64.98
66.67
38.89
66.35
48.35
34.8
0.05
1.4
12.1
49.85
36.1
0.05
1.5
12.2
20.8
14.07
0.1
1.83
4.8
56.98
59.58
100.0
30.95
60.33
12 Phosphorus (as P) 10.4 10.4 3.4 67.31 10.4 10.5 4.0 61.54
13 Oil & grease 34 34 33 2.94 34 35 33.33 1.96
14 H2 S 2.8 2.8 0.97 65.48 2.9 2.9 1.1 62.07
15 S V I 134 132 90 32.84 140 140 92 34.29
446
Table 32: 50days and 60 days time period effect along with 30%
volume of clay balls, 0.2% consortium and 10 hours
HRT for domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Time period – 50 days Time period – 60 days
Befo
re
treat
ment
Blan
k
After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.6 7.6 7.7 0.1 7.6 7.7 7.7 0.1
2 E.C 2240 2190 1830 18.30 2420 2400 1980 18.12
3 Temperature 27 28 28 1°C 27 27 27 -
4 TSS
340 345 105.33 69.02
370 374 114.6
7 69.01
5 VSS 138 132 62 55.07 152 144 68 55.26
6 Chlorides 178 184 58 67.42 178 182 60.33 66.1
7 Hardness
360 366 194.67 45.93
360 350 194.6
7 45.93
8 Alkalinity 460 450 207 55.0 390 380 178 54.36
9 C O D
510 512 172 66.27
490 498 166.3
3 66.05
10 B O D 144 148 54.67 62.04 212 214 79 62.74
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
49.8
38.3
0.1
1.6
9.8
51.4
39.8
0.1
1.7
9.8
21.7
15.7
0.14
1.8
4.07
56.42
59.01
36.67
12.5
58.5
50.1
38.2
0.1
1.1
10.7
52.1
39.8
0.1
1.8
10.4
21.81
15.83
0.14
1.4
4.43
56.47
58.55
40.0
27.27
58.57
12 Phosphorus (as P) 10.2 10.4 4.43 56.54 9.6 9.8 4.2 56.25
13 Oil & grease 32 32 31 3.13 34 34 33 2.94
14 H2 S 2.8 2.9 1.23 55.95 2.9 2.9 1.3 55.17
15 S V I 130 130 88 32.31 120 120 80 33.33
447
Table 33: 10% and 20% volume of sintered glass cylinders effect
as biofilter material in the presence of 0.2% consortium
and 12 hours HRT for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Volume – 10% Volume – 20%
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remov
al
(except
pH &
temp.)
Befor
e
treat
ment
Blank After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.8 7.8 7.8 - 7.9 7.9 7.9 -
2 E.C 1890 1840 1530 19.05 2140 2180 1720 19.63
3 Temperature 28 28 28 - 28 28 28 -
4 TSS 330 335 125.33 62.02 342 348 114.33 66.57
5 VSS 128 122 61.33 52.08 160 152 73.67 53.96
6 Chlorides 148 148 62 58.11 168 174 63.67 62.1
7 Hardness 295 300 180 38.98 310 300 170.33 45.05
8 Alkalinity 412 410 218 47.09 430 410 185 56.98
9 C O D 480 486 159 66.88 460 468 137.33 70.14
10 B O D 202 208 71 64.85 210 214 66 68.57
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
49.45
38.8
0.05
1.2
9.4
50.25
39.4
0.05
1.3
9.5
23.36
17.77
0.1
1.6
3.9
52.75
54.21
93.33
33.33
58.51
47.5
34.4
ND
1.5
11.6
49.41
36.2
0.01
1.5
11.7
18.83
12.73
0.06
1.9
4.13
60.36
62.98
26.67
64.37
12 Phosphorus (as P) 10.4 10.6 4.53 56.41 9.4 9.5 3.53 62.41
13 Oil & grease 38 38 38 - 38 38 38 -
14 H2 S 2.8 2.8 1.1 60.71 2.9 3.0 1.0 65.52
15 S V I 130 132 90 30.77 110 114 76 30.91
448
Table 34: 30% and 40% volume of sintered glass cylinders as
biofilter material effect along with 0.2% consortium
and 12 hours HRT for domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Volume – 30% Volume – 40%
Befo
re
trea
tme
nt
Blan
k
After
treatm
ent
(Mean
)
%
Remo
val
(exce
pt pH
&
temp.
)
Befor
e
treat
ment
Blank After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.9 7.9 7.9 - 7.8 7.8 7.8 -
2 E.C 204
0 2100 1614.6 20.85 1890 1910 1490 21.16
3 Temperature 28 28 28 - 27 27 27 -
4 TSS 375 380 106.33 71.64 400 400 110 72.5
5 VSS 110 108 46 58.18 140 136 58 58.57
6 Chlorides 145 148 45 68.97 170 172 50.67 70.2
7 Hardness 390 380 187 52.05 410 400 192.67 53.01
8 Alkalinity 520 510 213 59.04 480 460 187.33 60.97
9 C O D 460 468 120.33 73.84 480 488 124 74.17
10 B O D 195 202 53.33 72.65 204 212 56 72.55
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
51.5
40.3
0.05
1.4
9.75
53.56
41.9
0.06
1.5
10.1
18.75
13.7
0.08
1.77
3.2
63.59
66.0
66.67
26.19
67.18
41.06
29.4
0.06
1.0
10.6
42.77
30.8
0.07
1.1
10.8
14.23
9.4
0.1
1.43
3.3
65.34
68.03
61.11
43.33
68.87
12 Phosphorus (as P) 10.6 10.7 3.43 67.61 9.6 9.9 3.03 68.4
13 Oil & grease 32 32 32 - 36 36 36 -
14 H2 S 3.1 3.1 1.0 67.74 2.9 3.0 1.0 65.52
15 S V I 124 124 85 31.45 124 122 84 32.26
449
Table 35: 8 hours and 9 hours HRT effect along with 30%
volume of sintered glass cylinders and 0.2%
consortium for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT – 8 hours HRT – 9 hours
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befor
e
treat
ment
Blank After
treat
ment
(Mea
n)
%
Remo
val
(excep
t pH
&
temp.)
1 pH 7.8 7.8 7.8 - 7.8 7.8 7.8 -
2 E.C
1890 1910 1615 14.55 1880 1890 1593.
3 15.25
3 Temperature 28 27 27 1°C 27 27 27 -
4 TSS 345 351 139 59.71 318 320 114.33 64.05
5 VSS 134 130 65.33 51.24 129 124 70 45.74
6 Chlorides 190 192 84.33 55.61 170 171 70.33 58.63
7 Hardness 332 330 216.67 34.74 318 316 195.33 38.57
8 Alkalinity 426 430 245 42.49 432 430 229 46.99
9 C O D 440 444 178 59.55 448 450 157 64.96
10 B O D 192 194 76 60.42 200 202 73 63.5
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
40.28
29.6
0.08
1.1
9.5
42.08
31.2
0.08
1.2
9.6
22.65
16.37
0.12
1.47
4.7
43.76
44.71
50.0
33.33
50.53
47.85
34.6
0.05
1.4
11.8
49.25
35.8
0.05
1.5
11.9
23.16
15.93
0.09
1.8
5.33
51.61
53.95
80.0
28.57
54.8
12 Phosphorus (as P) 9.8 9.8 4.5 54.08 9.9 9.9 4.2 57.58
13 Oil & grease 33 33 33 - 36 36 36 -
14 H2 S 2.8 2.9 1.2 57.14 2.8 2.9 1.0 64.29
15 S V I 130 130 94 27.69 122 130 90 26.23
450
Table 36: 10 hours and 11hours HRT effect in presence of 30%
volume of sintered glass cylinders and 0.2%
consortium for domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT – 10 hours HRT – 11 hours
Befor
e
treat
ment
Blan
k
After
treatm
ent
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Before
treatm
ent
Bla
nk
After
treat
ment
(Mea
n)
%
Remo
val
(exce
pt pH
&
temp.
)
1 pH 7.6 7.6 7.6 - 7.8 7.8 7.8 -
2 E.C 2340 2320 1815 22.44 2240 2210 1725 22.99
3 Temperature 28 28 28 - 28 28 28 -
4 TSS 355 360 109 69.3 340 348 102.33 69.9
5 VSS 148 140 66 55.41 122 116 54 55.74
6 Chlorides 190 192 52.33 72.46 163 168 44 73.01
7 Hardness 360 355 199 44.72 415 415 228.33 44.98
8 Alkalinity 470 465 214 54.47 430 428 193.67 54.96
9 C O D 515 518 149.33 71.0 485 490 143.33 70.45
10 B O D 183 186 54 70.49 204 206 59 71.08
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
50.28
38.6
0.08
1.4
10.2
51.28
39.4
0.08
1.5
10.3
19.81
14.1
0.11
1.8
3.8
60.59
63.47
41.67
28.57
62.75
49.5
35.7
ND
1.4
12.4
50.4
36.4
ND
1.5
12.5
19.25
12.8
0.05
1.8
4.6
61.11
64.15
28.57
62.9
12 Phosphorus (as P) 9.8 9.8 3.6 63.27 9.9 9.9 3.47 64.98
13 Oil & grease 32 32 32 - 29 29 29 -
14 H2 S 2.8 2.9 1.0 64.29 2.8 2.9 1.0 64.29
15 S V I 136 140 92 32.35 140 140 90 35.71
451
Table 37: 12hours HRT, 30% volume of sintered glass cylinders
and 0.2% consortium effect in domestic sewage
treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
HRT – 12 hours
Before
treatment
Blank After
treatment
(Mean)
% Removal
(except pH
& temp.)
1 pH 7.7 7.7 7.8 0.1
2 E.C 2340 2300 1800 23.08
3 Temperature 27 27 27 -
4 TSS 364 368 109.33 69.96
5 VSS 158 150 69.33 56.12
6 Chlorides 178 176 48 73.03
7 Hardness 360 350 198 45.0
8 Alkalinity 385 380 173 55.06
9 C O D 520 522 153.33 70.51
10 B O D 212 214 61 71.23
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
50.5
38.6
0.1
1.2
10.6
51.9
39.8
0.1
1.3
10.7
19.52
13.87
0.15
1.6
3.9
61.35
64.08
50.0
33.33
63.21
12 Phosphorus (as P) 10.4 10.4 3.6 65.38
13 Oil & grease 34 34 34 -
14 H2 S 2.9 2.9 1.0 65.52
15 S V I 130 130 85 34.62
452
Table 38: 10days and 20 days time period effect along with 30%
volume of sintered glass cylinders, 0.2% consortium
and 10 hours HRT for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
Time period – 10 days Time period – 20 days
Befo
re
treat
ment
Blank After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Befo
re
treat
ment
Blank After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.8 7.8 7.8 - 7.6 7.6 7.6 -
2 E.C 2460 2410 1990 19.11 2260 2240 1830 19.03
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 370 374 109.33 70.45 340 345 98.67 70.98
5 VSS 190 182 82 56.84 128 122 47.67 62.76
6 Chlorides 216 218 65 69.91 172 174 51.67 69.96
7 Hardness
390 385 212.33 45.56 386 380 202.6
7 47.5
8 Alkalinity
420 410 189 55.0 422 416 185.6
7 56.0
9 C O D
490 494 139.33 71.56
478 422 131.3
3 72.52
10 B O D 182 184 51.67 71.61 155 162 43.33 72.04
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
40.55
29.6
0.05
1.1
9.8
42.35
31.2
0.05
1.2
9.9
16.13
11.00
0.09
1.43
3.6
60.23
62.84
86.67
30.3
63.27
48.1
36.4
ND
0.9
10.8
50.02
38.1
0.02
1.0
10.9
18.22
13.10
0.05
1.37
3.7
62.13
64.01
-
51.85
65.74
12 Phosphorus (as P) 9.6 9.5 3.5 63.54 10.2 10.3 3.5 65.69
13 Oil & grease 39 40 38 2.56 42 42 42 -
14 H2 S 2.9 2.9 1.0 65.52 2.9 2.9 1.0 65.52
15 S V I 120 128 78 35.0 115 115 80 30.43
453
Table 39: 30days and 40 days time period effect along with 30%
volume of sintered glass cylinders, 0.2% consortium
and 10 hours HRT for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
Time period – 30 days Time period – 40 days
Before
treatm
ent
Blank After
treatm
ent
(Mean
)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mean
)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.7 7.7 0.1 7.8 7.8 7.8 -
2 E.C 2260 2240 1813.3 19.76 2410 2360 1830 19.92
3 Temperature 27 28 28 1°C 28 28 28 -
4 TSS 318 320 89 72.01 390 394 121 68.97
5 VSS 132 126 54.67 58.59 168 162 70.33 58.13
6 Chlorides 174 178 52 70.11 184 188 57 69.02
7 Hardness 306 312 151.33 50.54 340 330 170 50.0
8 Alkalinity 439 430 189 56.95 480 475 211 56.04
9 C O D 470 472 131.33 72.06 510 512 168 67.06
10 B O D 198 202 53.33 73.06 204 208 65.33 67.97
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
46.85
34.2
0.05
1.2
11.4
48.96
35.9
0.06
1.4
11.6
17.39
11.93
0.09
1.47
3.9
62.89
65.11
73.33
22.22
65.79
51.7
40.6
0.1
1.2
9.8
53.2
41.9
0.1
1.3
9.9
21.73
16.2
0.1
1.53
3.9
57.96
60.1
-
27.78
60.2
12 Phosphorus (as P) 8.9 9.0 2.97 66.67 10.4 10.7 4.0 61.54
13 Oil & grease 28 28 28 - 38 39 38 -
14 H2 S 2.8 2.9 0.97 65.48 3.1 3.1 1.17 62.37
15 S V I 122 124 32.79 65.15 130 138 87 33.08
454
Table 40: 50days and 60 days time period effect along with 30%
volume of sintered glass cylinders, 0.2% consortium
and 10 hours HRT for domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Time period – 50 days Time period – 60 days
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befo
re
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.8 7.8 7.8 - 7.6 7.6 7.7 0.1
2 E.C 1980 1920 1615 18.43 2160 2120 1770 18.06
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 318 322 98.33 69.08 370 375 115 68.92
5 VSS 148 142 66.33 55.18 138 132 62 55.07
6 Chlorides 162 164 51.33 58.31 168 172 57 66.07
7 Hardness 360 350 194.33 46.02 410 405 221 46.1
8 Alkalinity 410 400 184 55.12 470 470 216 54.04
9 C O D 465 470 158 66.02 510 512 173 66.08
10 B O D 184 188 70 61.96 198 204 73 63.13
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
51.28
38.2
0.08
1.2
11.8
53.08
39.8
0.08
1.3
11.9
22.14
15.6
0.11
1.53
4.9
56.82
59.16
37.5
27.78
58.47
42.1
30.4
0.1
1.2
10.4
43.8
31.9
0.1
1.3
10.5
18.78
12.73
0.14
1.53
4.37
55.4
55.11
43.33
27.78
58.01
12 Phosphorus (as P) 10.2 10.2 4.37 57.19 10.8 10.9 4.3 60.19
13 Oil & grease 33 34 32.33 2.02 38 39 37 2.63
14 H2 S 2.7 2.8 1.2 55.56 2.8 2.9 1.1 60.71
15 S V I 122 130 80 34.43 118 120 75 36.44
455
Table 41: 10%and 20% volume of corn cobs effect as biofilter
material along with 0.2% consortium and 12 hours
HRT for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature & SVI)
Volume – 10% Volume – 20%
Befor
e
treat
ment
Blank After
treatm
ent
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
1 pH 7.6 7.6 7.6 - 7.4 7.4 7.4 -
2 E.C 2420 2380 2170 10.33 2520 2480 2270 9.92
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 400 410 168 58.0 390 396 179.67 53.93
5 VSS 128 122 65 49.22 142 128 78 45.07
6 Chlorides 168 174 75.33 55.16 172 178 87 49.42
7 Hardness 340 330 240 29.41 400 380 298.67 25.33
8 Alkalinity 430 415 243.67 43.33 440 420 272 38.18
9 C O D 510 518 205 59.8 490 496 240 51.02
10 B O D 198 204 83 58.08 168 178 80.67 51.98
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
41.45
30.6
0.05
1.0
9.8
42.95
38.9
0.05
1.1
9.9
21.66
15.33
0.1
1.33
4.9
47.74
49.89
93.33
33.33
50.0
49.5
38.1
0.1
1.2
10.1
51.1
39.6
0.1
1.2
10.2
27.92
21.3
0.12
1.33
5.6
43.6
44.09
16.67
11.11
44.55
12 Phosphorus (as P) 10.6 10.8 5.3 50.0 11.6 11.8 6.5 43.97
13 Oil & grease 50.4 50 50 0.79 42.5 42.5 42 1.18
14 H2 S 2.8 2.9 1.35 51.79 2.9 2.9 1.5 48.28
15 S V I 128 130 88 31.25 130 132 88 32.31
456
Table 42: Effect of 10% and 20% volume of hollow cylindrical
corn cobs as biofilter material in the presence of 0.2%
consortium and 12 hours HRT for domestic sewage
treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature & SVI)
Volume – 10% Volume – 20%
Befor
e
treat
ment
Blank After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatm
ent
Blank After
treat
ment
(Mea
n)
%
Remov
al
(excep
t pH &
temp.)
1 pH 7.9 7.9 7.8 0.1 7.8 7.8 7.77 0.03
2 E.C 2180 2090 1736.6 20.34 1970 1920 1570 20.30
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 318 320 106 66.67 352 356 102 71.02
5 VSS 128 120 50.33 60.68 212 204 76.33 63.99
6 Chlorides 162 168 62 61.73 158 162 50.67 67.93
7 Hardness
370 360 188 49.19 360 350 165.6
7 53.98
8 Alkalinity
410 400 194 52.68 380 360 159.6
7 57.98
9 C O D
460 468 144.33 68.62
420 428 100.6
7 76.03
10 B O D 198 202 64.67 67.34 174 184 43.67 74.9
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
40.62
31.2
0.02
0.9
8.5
42.02
32.4
0.02
1.0
8.6
17.16
12.43
0.06
1.37
3.3
57.75
60.15
200.0
51.85
61.18
40.45
29.9
0.05
1.1
9.4
42.36
31.6
0.06
1.2
9.5
14.87
10.4
0.1
1.47
2.9
63.25
65.22
100.0
33.33
69.15
12 Phosphorus (as P) 9.4 9.4 3.9 58.51 9.6 9.6 3.53 63.19
13 Oil & grease 44 43 42 4.55 39 38 36.67 5.98
14 H2 S 2.7 2.8 0.96 64.32 2.9 2.9 1.0 65.52
15 S V I 120 124 80 33.33 128 130 82 35.94
457
Table 43: Effect of 30% and 40% volume of hollow cylindrical
corn cobs as biofilter material in the presence of 0.2%
consortium and 12 hours HRT for domestic sewage
treatment
S.
N
o
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Volume – 30% Volume – 40%
Befor
e
treat
ment
Blank After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Befor
e
treat
ment
Blank After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.6 - 7.8 7.8 7.7 0.1
2 E.C 2420 2380 1920 20.66 2220 1980 1760 20.72
3 Temperature 26.5 26 26 0.5°C 26 26 26 -
4 TSS 360 370 100.33 72.13 348 356 94.67 72.8
5 VSS 128 118 44.67 65.1 172 168 59 65.7
6 Chlorides 172 176 53.33 68.99 182 184 55 69.78
7 Hardness 395 390 170 56.96 395 390 166 57.97
8 Alkalinity 421 420 168.33 60.02 390 380 156 60.0
9 C O D 472 480 104 77.97 395 398 80 79.75
10 B O D 198 202 47 76.26 184 198 39 78.8
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
47.74
36.2
0.04
0.9
10.6
49.55
37.8
0.05
1.0
10.7
16.63
11.97
0.1
1.37
3.2
65.17
66.94
141.67
51.85
69.81
51.48
38.6
0.08
1.2
11.6
52.58
39.36
0.08
1.2
11.7
17.31
12.3
0.11
1.57
3.33
66.37
68.13
41.67
30.56
71.26
12 Phosphorus (as P) 11.2 11.2 4.03 63.99 10.8 10.8 3.8 64.81
13 Oil & grease 51 49 48 5.88 33 32 30 9.09
14 H2 S 2.9 2.9 0.97 66.67 2.8 2.9 0.97 65.48
15 S V I 130 132 80 38.46 138 140 80 42.03
458
Table 44: 8 hours and 9 hours HRT effect along with 20%
volume of hollow cylindrical corncobs and 0.2%
consortium for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT – 8 hours HRT – 9 hours
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(exce
pt pH
&
temp.
)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Rem
oval
(exce
pt
pH &
temp.
)
1 pH 7.6 7.6 7.6 - 7.5 7.5 7.5 -
2 E.C 2350 2280 1865 20.64 2680 2580 2120 20.90
3 Temperature 25.5 25 25 0.5°C 26 26 26 -
4 TSS 385 356 124.33 64.98 380 370 80 78.95
5 VSS 148 140 65.33 55.86 148 140 50.67 65.77
6 Chlorides 184 188 75.67 58.88 180 184 57.33 68.15
7 Hardness 375 360 217 42.13 295 270 118 60.0
8 Alkalinity 415 400 216 47.95 375 360 146 61.07
9 C O D 490 500 156.67 68.03 440 450 97 77.95
10 B O D 182 186 60 67.03 186 194 40.67 78.14
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
45.89
34.6
0.09
1.4
9.8
47.3
35.9
0.1
1.4
9.9
20.94
14.8
0.14
1.8
4.2
54.36
57.23
59.26
29.57
57.14
40.16
29.2
0.06
1.0
9.9
42.77
31.6
0.07
1.1
10.0
14.13
9.3
0.1
1.43
3.3
64.81
68.15
66.67
43.33
66.67
12 Phosphorus (as P) 11.2 11.1 4.7 58.04 10.8 1.9 3.4 68.52
13 Oil & grease 34 34 33 2.94 38 38 37 2.63
14 H2 S 2.8 2.9 1.0 64.29 2.9 2.9 0.95 67.24
15 S V I 118 124 70 40.68 120 124 70 41.67
459
Table 45: 10 hours and 11 hours HRT effect along with 20%
volume of hollow cylindrical corncobs and 0.2%
consortium for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
HRT – 10 hours HRT – 11 hours
Befor
e
treat
ment
Blank After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befo
re
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.8 7.8 7.7 0.1 7.7 7.7 7.7 -
2 E.C
1890 1820 1503.3 20.46 2310 2260 1836.
6 20.49
3 Temperature 26 26 26 - 25.5 25 25 0.5°C
4 TSS 345 348 62 82.03 318 320 56.67 82.18
5 VSS 128 122 42.67 66.67 124 120 41 66.94
6 Chlorides 158 162 49 68.99 168 172 51.67 69.25
7 Hardness
310 300 118 61.94 310 300 116.6
7 62.37
8 Alkalinity 315 300 116.67 62.96 406 390 149 63.3
9 C O D 420 426 88 79.05 460 463 94.33 79.49
10 B O D 204 208 44.67 78.1 198 202 42.33 78.63
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
45.82
32.8
0.02
1.4
11.6
47.13
34.1
0.3
1.4
11.6
16.96
11.4
0.06
1.7
3.8
62.98
65.24
216.67
21.43
67.24
45.36
34.2
0.06
1.2
9.9
47.17
36.1
0.07
1.2
9.8
16.63
11.8
0.09
1.53
3.2
63.35
65.50
55.56
27.78
67.68
12 Phosphorus (as P) 12.2 12.3 3.6 70.49 12.3 12.4 3.6 70.73
13 Oil & grease 29 28 28 3.45 28 28 27 3.57
14 H2 S 2.9 2.9 0.95 67.24 2.9 2.9 0.9 68.97
15 S V I 126 128 72 42.86 130 130 68 47.69
460
Table 46: 12 hours HRT effect in domestic sewage treatment
along with 20% volume of hollow cylindrical
corncobs and 0.2% consortium
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
HRT – 12 hours
Before
treatment
Blank After
treatment
(Mean)
% Removal
(except pH
& temp.)
1 pH 7.6 7.6 7.5 0.1
2 E.C 2420 2380 1920 20.66
3 Temperature 26 26 26 -
4 TSS 372 378 65 82.53
5 VSS 154 144 50 67.53
6 Chlorides 178 178 52 70.79
7 Hardness 358 350 132.33 63.04
8 Alkalinity 390 350 138 64.62
9 C O D 490 494 95.67 80.48
10 B O D 212 212 38.67 81.76
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
51.19
39.2
0.09
1.1
10.8
53.49
41.4
0.09
1.1
10.9
18.48
13.37
0.14
1.57
3.4
63.91
65.9
59.26
42.42
68.52
12 Phosphorus (as P) 9.9 9.9 2.7 72.73
13 Oil & grease 34 33 32 5.88
14 H2 S 2.9 2.9 0.96 67.01
15 S V I 122 120 62 49.18
461
Table 47: 10 days and 20 days time period in domestic sewage
treatment along with 20% volume of hollow
cylindrical corncobs, 0.2% consortium and 9 hours
HRT
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Time period – 10 days Time period – 20 days
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(excep
t pH &
temp.)
Before
treatm
ent
Blan
k
Afte
r
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 8.1 8.1 8.0 0.1 7.9 7.9 7.9 -
2 E.C 2340 2320 1850 20.94 2260 2180 1785 21.02
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 355 348 67.33 81.03 345 354 59.33 82.8
5 VSS 140 130 44.33 68.33 148 141 45.67 69.14
6 Chlorides 188 189 58.67 68.79 158 164 45.67 71.1
7 Hardness 360 350 138.67 61.48 330 315 119 63.94
8 Alkalinity 410 400 156 61.95 390 365 136.5 65.0
9 C O D 460 466 91.33 80.14 436 442 82.67 81.04
10 B O D 174 182 29.5 83.05 178 184 30 83.15
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
40.08
29.5
0.08
0.9
9.6
43.59
32.8
0.09
1.0
9.7
13.18
8.77
0.14
1.47
2.8
67.12
70.28
79.17
62.96
70.83
41.95
31.6
0.05
1.1
9.2
43.46
33.1
0.06
1.1
9.3
13.06
8.8
0.09
1.53
2.63
68.87
72.15
86.67
39.39
71.38
12 Phosphorus (as P) 10.9 10.9 3.1 71.56 10.4 10.6 2.8 73.08
13 Oil & grease 28 28 27 3.57 38 38 37 2.63
14 H2 S 2.8 2.9 0.83 70.24 2.9 2.9 0.8 70.41
15 S V I 130 132 65 50.00 130 132 64 50.77
462
Table 48: 30 days and 40 days time period in domestic sewage
treatment along with 20% volume of hollow
cylindrical corncobs, 0.2% consortium and 9 hours
HRT
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Time period – 30 days Time period – 40 days
Befo
re
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befo
re
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remov
al
(except
pH &
temp.)
1 pH 7.7 7.7 7.7 - 7.7 7.7 7.7 -
2 E.C 2300 2260 1815 21.09 2180 2120 1720 21.1
3 Temperature 25.5 25 25 0.5°C 26 26 26 -
4 TSS 395 398 67 83.04 372 384 63.33 82.97
5 VSS 174 168 41.67 76.05 166 160 39.33 76.31
6 Chlorides 152 158 42.67 71.93 158 158 44.33 71.94
7 Hardness 385 380 131 65.97 375 360 127.17 66.09
8 Alkalinity 430 415 142 66.98 400 380 132 67.0
9 C O D 470 478 84 82.13 460 466 81.33 82.32
10 B O D 168 174 26 84.52 192 198 29.33 84.72
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
53.89
40.2
0.09
1.3
12.3
55.4
41.6
0.1
1.3
12.4
15.98
10.83
0.14
1.7
3.3
70.35
73.05
59.26
30.77
73.17
46
34.8
0.1
1.2
9.9
47.3
36.1
0.1
1.2
9.9
13.65
9.4
0.15
1.5
2.6
70.32
72.99
53.33
25.0
73.74
12 Phosphorus (as P) 11.8 11.9 2.97 74.86 10.7 10.8 2.7 74.77
13 Oil & grease 42.5 43 41.33 2.75 42 42 40 4.76
14 H2 S 2.9 2.9 0.7 75.86 2.9 2.9 0.7 75.86
15 S V I 140 138 66 52.86 132 130 58 56.06
463
Table 49: 50days and 60 days time period effect in domestic
sewage treatment along with 20% volume of hollow
cylindrical corncobs, 0.2% consortium and 9 hours
HRT
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature & SVI)
Time period – 50 days Time period – 60 days
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befor
e
treat
ment
Blank After
treatm
ent
(Mean
)
%
Remo
val
(exce
pt pH
&
temp.
)
1 pH 7.4 7.4 7.4 - 7.5 7.5 7.5 -
2 E.C 2480 2290 1985 19.96 2360 2280 1890 19.92
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 355 362 71 80.0 350 356 69.67 80.1
5 VSS 140 142 40 71.43 142 136 45.33 68.08
6 Chlorides 190 194 64.33 66.14 178 182 64 64.04
7 Hardness 360 340 126 65.0 340 330 122.33 64.02
8 Alkalinity 470 420 160 65.96 415 390 149.33 64.02
9 C O D 510 512 101 80.2 490 496 108 77.96
10 B O D 188 198 35 81.38 194 198 38.77 80.02
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
39.59
28.6
0.09
1.0
9.9
41.99
30.9
0.09
1.1
9.9
12.58
8.3
0.11
1.43
2.83
68.22
70.98
25.93
43.33
71.38
42.12
31.2
0.05
1.1
9.8
43.95
32.9
0.05
1.1
9.9
14.6
9.6
0.09
1.43
3.03
66.41
69.23
80.0
30.3
69.05
12 Phosphorus (as P) 10.8 10.9 3.1 71.3 10.2 10.3 3.2 68.63
13 Oil & grease 38 36 36 5.26 36 36 34.33 4.63
14 H2 S 2.8 2.9 0.73 73.81 2.9 2.9 0.9 68.97
15 S V I 138 140 60 56.52 124 128 55 55.65
464
Table 50: 10% volume and 20% volume of wood chips effect in
domestic sewage treatment in presence of 0.2%
consortium and 12 hours HRT
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Volume – 10% Volume – 20%
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Before
treatm
ent
Blan
k
Afte
r
treat
ment
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.5 0.1 7.3 7.2 7.4 0.1
2 E.C 2340 2280 1920 17.97 2160 2120 1760 18.52
3 Temperature 28 27 27 1.0°C 27 27 27 -
4 TSS 400 410 144.67 63.83 380 388 132.3
3 65.18
5 VSS 164 156 69 57.93 152 146 62.33 58.99
6 Chlorides 158 154 63 60.13 172 178 63.67 62.98
7 Hardness 370 355 185 50.0 400 385 194 51.5
8 Alkalinity 460 445 211.33 54.06 480 460 212 55.83
9 C O D 480 488 158.67 66.94 510 518 153 70.0
10 B O D 210 214 69 67.14 162 174 48.33 70.16
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
44.05
32.5
0.05
1.1
10.4
45.56
33.9
0.06
1.1
10.5
18.93
13.3
0.1
1.43
4.1
57.02
59.08
100.0
30.3
60.58
50.5
37.5
ND
1.2
11.8
52.01
38.9
0.01
1.2
11.9
20.51
14.6
0.05
1.57
4.3
59.38
61.07
30.56
63.56
12 Phosphorus (as P) 8.9 9.1 3.7 58.43 9.8 10.1 3.9 60.2
13 Oil & grease 46.25 46 46 0.54 32 32 31 3.13
14 H2 S 2.9 2.9 1.0 65.52 2.8 2.9 0.95 66.07
15 S V I 118 120 88 25.42 124 128 90 27.42
465
Table 51: 30% volume and 40% volume of wood chips effect in
domestic sewage treatment in presence of 0.2%
consortium and 12 hours HRT
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature & SVI)
Volume – 30% Volume – 40%
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatme
nt
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.2 7.2 7.3 0.1 7.4 7.4 7.4 -
2 E.C 2190 2110 1750 20.09 2520 2460 2015 20.04
3 Temperature 29 27 27 2.0°C 27 27 27 -
4 TSS 355 360 103 70.99 410 410 117 71.46
5 VSS 140 132 51 63.57 168 160 60.33 64.09
6 Chlorides 143 144 45.67 68.07 138 130 43.67 68.36
7 Hardness 360 350 165.67 53.98 340 315 153 55.0
8 Alkalinity 430 410 176.33 58.99 460 450 184 60.0
9 C O D 460 468 110 76.09 520 526 120 76.92
10 B O D 198 202 50.17 74.66 220 222 50.67 76.97
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
41.92
30.62
0.1
1.2
10.0
43.4
31.9
0.1
1.3
10.1
15.53
10.7
0.14
1.57
3.07
62.96
65.06
43.33
30.56
69.33
44.05
31.2
ND
1.25
11.96
45.9
32.8
0.1
1.3
11.7
15.64
10.6
0.04
1.5
3.5
64.49
66.03
20.0
69.83
12 Phosphorus (as P) 10.9 11.1 4.03 63.0 9.5 9.6 3.4 64.21
13 Oil & grease 28 28 27 3.57 42 42 40.67 3.17
14 H2 S 3.0 3.0 1.0 66.67 2.9 2.9 0.95 67.24
15 S V I 128 130 92 28.13 130 130 92 29.23
466
Table 52: 8 hours and 9 hours HRT effect in presence of 30%
volume of wood chips and 0.2% consortium for
domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT @ 8 hours HRT @ 9 hours
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befo
re
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.9 7.8 7.8 0.1 7.4 7.4 7.4 -
2 E.C 2800 2730 2270 18.93 2260 2210 1820 19.47
3 Temperature 24 24 24 - 25 25 25 -
4 TSS 380 388 137 63.95 350 360 103 70.57
5 VSS 164 156 74 54.88 170 160 69.67 59.02
6 Chlorides 168 169 70 58.33 204 209 76 62.75
7 Hardness 400 380 240 40.0 360 345 179 50.28
8 Alkalinity 420 400 229 45.48 415 400 199 52.05
9 C O D 480 488 156 67.5 490 498 137 72.04
10 B O D 198 204 65.67 66.84 202 208 57.67 71.45
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
47
35.5
0.1
1.6
9.8
47.8
36.2
0.1
1.6
9.9
20.91
14.9
0.14
1.87
4.0
55.52
58.03
40.0
16.67
59.18
41.7
30.6
ND
1.0
10.1
43.11
31.9
0.01
1.0
10.2
15.91
11.6
0.05
1.47
2.8
61.84
62.09
46.67
72.28
12 Phosphorus (as P) 11.2 11.3 4.97 55.67 9.8 9.9 4.0 59.18
13 Oil & grease 37.5 37 37 1.33 38 38 37 2.63
14 H2 S 2.9 2.9 1.1 62.07 2.9 2.9 1.07 63.22
15 S V I 130 130 90 31.77 140 140 94 32.86
467
Table 53: 10 hours and 11 hours HRT effect in presence of 30%
volume of wood chips and 0.2% consortium for
domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT @ 10 hours HRT @ 11 hours
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.6 - 7.7 7.7 7.6 0.1
2 E.C 2340 2280 1810 22.65 2300 2280 1810 21.30
3 Temperature 26 26 26 - 27 26 26 1°C
4 TSS 360 366 71.33 80.19 390 396 74.33 80.94
5 VSS 132 128 47.33 64.14 178 168 62 65.17
6 Chlorides 178 182 58.67 67.04 154 160 50 67.53
7 Hardness 384 376 151.33 60.59 380 355 144.33 62.02
8 Alkalinity 432 420 170.33 60.57 420 405 164 60.95
9 C O D 490 498 95.67 80.48 470 478 89.67 80.92
10 B O D 115 122 30 73.91 148 156 32 78.38
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
48.75
37.2
0.05
1.3
10.2
50.45
38.6
0.05
1.4
10.4
17.35
12.3
0.09
1.67
3.3
64.4
66.94
73.33
28.21
67.65
51.5
40.1
ND
1.0
10.4
53.12
41.6
0.02
1.1
10.4
17.91
13.2
0.04
1.37
3.3
65.23
67.08
36.67
68.27
12 Phosphorus (as P) 10.9 11.0 3.6 66.97 9.5 9.6 3.1 67.37
13 Oil & grease 28 28 27.67 1.19 42.5 42 41.33 2.75
14 H2 S 2.9 2.9 0.95 67.24 2.8 2.8 0.9 67.86
15 S V I 132 130 88 33.33 118 120 76 35.59
468
Table 54: 12 hours HRT effect in presence of 30% volume of
wood chips and 0.2% consortium for domestic
sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
HRT @ 12 hours
Before
treatment
Blank After
treatment
(Mean)
% Removal
(except pH
& temp.)
1 pH 7.5 7.5 7.5 -
2 E.C 1960 1890 1550 20.92
3 Temperature 25 25 25 -
4 TSS 384 390 71 81.51
5 VSS 158 150 53.67 66.03
6 Chlorides 184 186 60 67.39
7 Hardness 384 370 142 63.02
8 Alkalinity 430 410 167.67 61.01
9 C O D 510 516 93 81.76
10 B O D 162 170 32 80.25
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
40.4
28.8
ND
1.1
10.5
42.92
31.1
0.02
1.2
10.6
13.81
9.2
0.04
1.37
3.2
65.82
68.06
24.24
69.52
12 Phosphorus (as P) 11.2 11.3 3.6 67.86
13 Oil & grease 38 38 37 2.63
14 H2 S 2.8 2.9 0.9 67.86
15 S V I 124 124 74 40.32
469
Table 55: 10 days and 20 days time period effect in presence of
30% volume of wood chips, 0.2% consortium and
10 hours HRT for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
Time period – 10 days Time period – 20 days
Before
treatme
nt
Blank After
treatme
nt
(Mean)
%
Remov
al
(except
pH &
temp.)
Before
treatm
ent
Blan
k
After
treat
ment
(Mea
n)
%
Remova
l
(except
pH &
temp.)
1 pH 7.5 7.5 7.5 - 7.6 7.6 7.5 0.1
2 E.C
2360 2280 1900 19.49 2480 2390 1986.
6 19.89
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 370 380 72 80.54 380 388 70.67 81.4
5 VSS 132 126 45 65.91 168 160 54 67.86
6 Chlorides 178 180 60 66.29 138 144 44 68.12
7 Hardness 360 340 137 61.94 340 325 126 62.94
8 Alkalinity 420 405 159.33 62.06 380 360 133.33 64.91
9 C O D 410 416 78 80.98 460 468 85 81.52
10 B O D 154 158 30.5 80.19 158 162 30 81.01
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
49.28
38.3
0.08
1.1
9.8
50.59
39.4
0.09
1.2
9.9
16.35
11.83
0.12
1.4
3.0
66.82
69.1
50.0
27.27
69.39
46.65
36.5
0.05
1.1
9.0
48.76
38.6
0.06
1.1
9.0
14.94
10.9
0.08
1.37
2.6
67.97
70.14
53.33
24.24
71.11
12 Phosphorus (as P) 10.6 10.7 3.3 68.87 9.5 9.6 2.7 71.58
13 Oil & grease 22.5 22 22 2.22 36.75 37 36 2.04
14 H2 S 3.1 3.0 1.0 67.74 2.9 2.9 0.85 70.69
15 S V I 130 130 84 35.38 130 132 80 38.46
470
Table 56: 30 days and 40 days time period effect in presence of
30% volume of wood chips, 0.2% consortium and
10 hours HRT for domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 30 days Time period – 40 days
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.
)
Befo
re
treat
ment
Blan
k
Afte
r
trea
tme
nt
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 8.1 8.1 8.0 0.1 7.9 7.9 7.8 0.1
2 E.C
2420 2380 1900 21.49
2350 2290 182
0 22.55
3 Temperature 26 26 26 - 25 25 25 -
4 TSS 320 328 58 81.88 318 324 55.67 52.49
5 VSS 148 140 47.67 67.79 148 140 47.33 68.02
6 Chlorides 172 176 53.67 68.8 182 186 56.67 68.86
7 Hardness 432 420 157.67 63.5 315 300 113 64.13
8 Alkalinity 460 440 156 66.09 440 400 149 66.14
9 C O D 490 496 88 82.04 495 498 86 82.63
10 B O D 168 172 29 82.74 176 182 29 83.52
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
50.99
39.2
0.09
1.2
10.5
52.4
40.6
0.1
1.2
10.5
16.72
12.1
0.12
1.5
3.0
67.2
69.13
37.04
25.0
71.43
43.8
32.6
0.1
1.3
9.8
45.21
33.9
0.11
1.3
9.9
13.94
9.4
0.14
1.6
2.8
68.17
71.17
43.33
23.08
71.43
12 Phosphorus (as P) 11.6 11.7 3.3 71.55 10.6 10.7 2.9 72.64
13 Oil & grease 40.25 41 38.67 3.93 33 33 32 3.03
14 H2 S 2.9 2.9 0.85 70.69 2.9 3.0 0.8 72.41
15 S V I 126 130 72 42.86 128 130 68 46.88
471
Table 57: 50 days and 60 days time period effect in presence of
30% volume of wood chips, 0.2% consortium and
10 hours HRT for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Time period – 50 days Time period – 60 days
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(except
pH &
temp.)
Befor
e
treat
ment
Blank After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.7 7.7 7.7 - 7.8 7.8 7.7 0.1
2 E.C 2300 2300 1780 22.61 2390 2210 1860 22.18
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 395 406 69.33 82.45 384 390 76.67 80.03
5 VSS 172 162 55 68.02 145 138 52 64.14
6 Chlorides 152 156 47.33 68.86 159 166 57.67 63.73
7 Hardness 355 360 138.33 64.07 390 365 156 60.0
8 Alkalinity 440 420 149 66.14 428 420 167 60.98
9 C O D 460 468 80 82.61 490 498 103 78.98
10 B O D 172 178 28.33 83.53 184 188 38.67 78.99
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
52.79
40.1
0.09
1.0
11.6
54.7
41.8
0.1
1.1
11.7
16.52
11.6
0.12
1.5
3.3
68.71
71.07
33.33
50.0
71.55
46.3
33.8
ND
1.1
11.4
46.91
34.2
0.01
1.2
11.5
16.38
11.1
0.05
1.53
3.7
64.61
67.16
39.39
67.54
12 Phosphorus (as P) 12.2 12.4 3.3 72.95 12.4 12.5 4.2 66.13
13 Oil & grease 42.5 42 41 3.53 31.9 32 31 2.82
14 H2 S 2.9 3.0 0.8 72.41 2.8 2.9 0.87 69.05
15 S V I 130 130 66 49.23 140 140 68 51.43
472
Table 58: 10% volume and 20% volume of nylon threads effect
in domestic sewage treatment with 0.2%
consortium and 12 hours HRT
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Volume – 10% Volume – 20%
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.
)
Befo
re
treat
ment
Blan
k
Afte
r
trea
tme
nt
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.5 0.1 7.8 7.8 7.7 0.1
2 E.C
2280 2190 1870 17.98 1980 1920 160
3.3 19.02
3 Temperature 26 26 26 - 27 26 26 1°C
4 TSS 315 320 112 64.44 320 326 107 66.56
5 VSS 142 136 62.33 56.1 120 114 48 60.0
6 Chlorides 174 178 70.33 59.58 155 160 56 63.87
7 Hardness 360 345 198 45.0 310 290 150.67 51.4
8 Alkalinity 390 360 204.67 47.52 360 340 167.67 53.43
9 C O D 425 429 138 67.53 420 426 122 70.95
10 B O D 178 184 58 67.42 169 174 50 70.41
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
47.34
36.4
0.05
1.1
9.8
46.45
35.3
0.05
1.2
9.9
20.27
14.9
0.07
1.4
3.9
57.18
59.07
46.67
27.27
60.2
47.32
35.8
0.02
1.2
10.3
48.23
36.7
0.03
1.2
10.3
18.52
13.2
0.05
1.47
3.8
60.86
63.16
166.67
22.22
63.11
12 Phosphorus (as P) 10.4 10.6 4.3 58.65 9.9 10.1 4.0 59.6
13 Oil & grease 33 33 32 3.03 34 33 33 2.94
14 H2 S 2.9 2.9 1.03 64.37 2.8 2.9 0.98 64.88
15 S V I 128 130 90 29.69 130 130 86 33.85
473
Table 59: 30% volume and 40% volume of nylon threads effect
in domestic sewage treatment with 0.2%
consortium and 12 hours HRT
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Volume – 30% Volume – 40%
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befor
e
treat
ment
Blan
k
Afte
r
trea
tme
nt
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 7.7 7.7 7.6 0.1 7.7 7.7 7.6 0.1
2 E.C
1980 1920 1600 19.19 2140 2080 172
0 19.63
3 Temperature 26 26 26 - 27 27 27 -
4 TSS 318 324 94 70.44 355 360 99.33 72.02
5 VSS 124 118 44.33 64.25 146 140 52.33 64.16
6 Chlorides 164 168 54 67.07 158 164 50.33 65.14
7 Hardness 330 315 156.33 52.63 345 330 158.3
3 54.11
8 Alkalinity 360 340 155 56.94 390 330 160 58.97
9 C O D 390 396 93.33 76.07 410 418 94.67 76.91
10 B O D 174 182 43.17 75.19 168 172 40.67 75.79
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
47.01
35.4
0.01
1.2
10.4
48.12
36.4
0.02
1.2
10.5
16.88
11.9
0.05
1.53
3.4
64.09
66.38
366.67
27.78
67.31
49.35
38.6
0.05
1.2
9.5
50.55
39.6
0.05
1.3
9.6
16.85
12.3
0.09
1.47
3.0
65.85
68.13
73.33
22.22
68.42
12 Phosphorus (as P) 9.8 9.9 3.6 63.27 9.8 9.9 3.5 64.29
13 Oil & grease 38 38 37 2.63 40 40 39 2.5
14 H2 S 2.9 2.9 0.95 67.24 2.9 2.9 0.95 67.24
15 S V I 130 132 82 36.92 120 120 74 38.33
474
Table 60: 8 hours and 9 hours HRT effect along with 30%
volume of nylon threads and 0.2% consortium for
domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
HRT @ 8 hours HRT @ 9 hours
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.
)
Befor
e
treat
ment
Blan
k
Afte
r
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.7 7.7 7.6 0.1 7.6 7.6 7.5 0.1
2 E.C 2180 2080 1730 20.64 2160 2080 1710 20.83
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 340 346 124 63.53 345 348 91 73.62
5 VSS 142 136 65 54.23 172 168 66 61.63
6 Chlorides 178 182 77.33 56.55 198 200 69.33 64.98
7 Hardness 360 330 218 39.44 360 340 172.6
7 52.04
8 Alkalinity 380 340 209.33 44.91 390 350 177.3
3 54.53
9 C O D 410 410 132 67.8 420 426 97.33 76.83
10 B O D 168 170 55.33 67.06 174 174 43.67 74.9
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
45.61
34.6
0.01
1.2
9.8
46.22
35.2
0.02
1.2
9.8
20.52
14.87
0.05
1.5
4.1
55.02
57.03
400.0
25.0
58.16
45.5
34.6
ND
1.1
9.8
46.21
35.2
0.01
1.1
9.9
16.57
11.8
0.04
1.43
3.3
63.58
65.9
30.30
66.33
12 Phosphorus (as P) 11.1 11.2 4.9 58.86 10.2 10.3 3.7 63.73
13 Oil & grease 36 35 35 2.78 38 38 37 2.63
14 H2 S 2.8 2.9 1.0 64.29 2.8 2.9 1.0 64.29
15 S V I 110 118 68 38.18 118 120 66 44.07
475
Table 61: 10 hours and 11 hours HRT effect along with 30%
volume of nylon threads and 0.2% consortium for
domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT @ 10 hours HRT @ 11 hours
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean)
%
Remo
val
(excep
t pH
&
temp.)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remov
al
(except
pH &
temp.)
1 pH 7.7 7.7 7.6 0.1 7.6 7.6 7.6 -
2 E.C 1920 1890 1523.3 20.66 2140 2080 1690 21.03
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 345 348 79.33 77.0 360 366 77.33 78.52
5 VSS 132 128 49 62.88 136 130 48.33 64.46
6 Chlorides 156 160 51.33 67.09 178 178 57.33 67.79
7 Hardness 310 300 133.33 56.99 340 330 136 60.0
8 Alkalinity 340 315 143 57.94 380 360 148 61.05
9 C O D 410 416 88 78.54 420 424 86 79.52
10 B O D 172 178 40 76.74 158 142 36.33 77.0
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
45.62
33.6
0.02
1.2
10.8
46.52
34.3
0.02
1.3
10.9
16.06
11.03
0.04
1.47
3.5
64.8
67.16
116.67
22.22
67.59
47.12
36.2
0.02
1.1
9.8
48.12
37.1
0.02
1.1
9.9
16.85
12.3
0.05
1.4
3.1
64.24
66.02
150.0
27.27
68.37
12 Phosphorus (as P) 10.6 10.6 3.7 65.09 10.4 10.5 3.3 68.27
13 Oil & grease 32 32 31 3.13 30 30 29 3.33
14 H2 S 2.9 2.9 1.0 65.52 2.9 2.9 0.95 67.24
15 S V I 120 120 64 46.67 120 120 60 50.00
476
Table 62: 12 hours HRT effect along with 30% volume of nylon
threads and 0.2% consortium for domestic sewage
treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
HRT @ 12 hours
Before
treatment
Blank After
treatment
(Mean)
% Removal
(except pH
& temp.)
1 pH 7.9 7.9 7.9 -
2 E.C 2430 2360 1925 20.78
3 Temperature 26 26 26 -
4 TSS 380 387 75.33 80.18
5 VSS 156 148 53 66.03
6 Chlorides 212 214 66.67 68.55
7 Hardness 380 360 142 62.63
8 Alkalinity 400 360 152 62.0
9 C O D 390 396 75.33 80.68
10 B O D 186 192 36.33 80.47
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
47.62
36.3
0.02
1.2
10.1
48.52
37.1
0.02
1.2
10.2
16.59
11.97
0.06
1.47
3.1
65.16
67.03
183.33
22.22
69.31
12 Phosphorus (as P) 10.6 10.7 3.27 69.18
13 Oil & grease 38 38 37 2.63
14 H2 S 2.8 2.9 0.9 67.86
15 S V I 130 132 62 52.31
477
Table 63: 10 days and 20 days time period effect in domestic
sewage treatment along with 30% volume of nylon
threads, 0.2% consortium and 9 hours HRT
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 10 days Time period – 20 days
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.
)
Befo
re
treat
ment
Blan
k
Afte
r
treat
ment
(Me
an)
%
Remo
val
(excep
t pH
&
temp.)
1 pH 7.7 7.7 7.6 0.1 7.6 7.6 7.5 0.1
2 E.C 2160 2090 1680 22.22 2240 2140 1750 21.88
3 Temperature 27 27 27 - 26 26 26 -
4 TSS 350 357 77 78.0 295 302 62 78.98
5 VSS 130 128 45 65.38 118 115 40 66.10
6 Chlorides 168 168 54.33 67.66 156 158 49.33 65.38
7 Hardness 360 340 151.33 51.96 330 315 132 60.0
8 Alkalinity 380 345 155 59.21 360 350 140.3
3 61.02
9 C O D 420 422 86.33 79.44 355 360 71.33 79.91
10 B O D 162 164 30 81.48 158 162 28.33 82.07
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
46.94
36.2
0.04
0.9
9.8
48.45
37.6
0.05
0.9
9.9
15.74
11.2
0.08
1.37
3.1
66.46
69.06
91.67
51.85
68.37
41.41
31.4
0.01
0.8
9.2
42.82
32.6
0.02
0.9
9.3
13.54
9.4
0.04
1.23
2.87
67.3
70.06
300.0
54.17
68.84
12 Phosphorus (as P) 10.4 10.5 3.2 69.23 10.1 10.2 3.1 69.31
13 Oil & grease
34 34 33.33 1.96 30 30 29.6
7 1.11
14 H2 S 2.8 2.9 0.9 67.86 2.8 2.9 0.9 67.86
15 S V I 120 120 64 46.67 118 120 62 47.46
478
Table 64: 30 days and 40 days time period effect in domestic
sewage treatment along with 30% volume of nylon
threads, 0.2% consortium and 9 hours HRT
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 30 days Time period – 40 days
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befor
e
treat
ment
Blan
k
Afte
r
trea
tme
nt
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 7.7 7.7 7.6 0.1 7.8 7.8 7.7 0.1
2 E.C 1860 1820 1410 24.19 1630 1620 1270 22.09
3 Temperature 26 26 26 - 26 26 26 -
4 TSS 315 318 63.33 79.89 315 318 62.33 80.21
5 VSS 120 118 38 68.33 128 122 38 70.31
6 Chlorides 148 150 44.67 69.82 122 126 35.33 71.04
7 Hardness 340 330 127.67 62.45 360 340 131.3
3 63.52
8 Alkalinity 380 360 140.67 62.98 380 360 137 63.95
9 C O D 390 392 76 80.51 380 384 73 80.79
10 B O D 172 174 29 83.14 184 186 29 84.24
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
41.94
31.6
0.04
1.1
9.2
42.54
32.0
0.04
1.2
9.3
13.41
9.1
0.08
1.43
2.8
68.03
71.2
91.67
30.30
69.57
42.61
32.4
0.01
1.0
9.2
44.33
33.8
0.03
1.1
9.4
13.0
9.03
0.04
1.33
2.6
69.48
72.12
266.67
33.33
71.74
12 Phosphorus (as P) 10.4 10.5 3.0 71.15 9.8 9.9 2.7 72.45
13 Oil & grease 34 34 33 2.94 40 40 39 2.5
14 H2 S 2.7 2.8 0.87 67.9 2.8 2.8 0.9 67.86
15 S V I 124 124 62 50.00 130 130 62 52.31
479
Table 65: 50 days and 60 days time period effect in domestic
sewage treatment along with 30% volume of nylon
threads, 0.2% consortium and 9 hours HRT
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 50 days Time period – 60 days
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remo
val
(exce
pt pH
&
temp.
)
1 pH 7.5 7.5 7.5 - 7.7 7.7 7.6 0.1
2 E.C 2240 2190 1748.3 21.95 1980 1940 1540 22.22
3 Temperature 26 26 26 - 27 27 27 -
4 TSS 340 342 66.67 80.39 370 374 70 81.08
5 VSS 128 126 36.67 71.35 128 120 35 72.66
6 Chlorides 144 148 40.33 71.99 174 178 47 72.99
7 Hardness 360 330 129.33 64.07 395 360 133.67 66.16
8 Alkalinity 390 385 138.67 64.44 410 390 135.67 66.91
9 C O D 390 390 74 81.03 480 484 88 81.67
10 B O D 188 186 28.67 84.75 198 202 29.33 85.19
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
44.72
33.4
0.02
1.4
9.9
45.32
33.9
0.02
1.5
9.9
13.65
9.2
0.05
1.63
2.77
69.48
72.46
133.33
16.67
72.05
48.33
36.8
0.03
1.1
10.4
49.73
38.1
0.03
1.1
10.5
14.12
9.9
0.05
1.37
2.8
70.78
73.1
77.78
24.24
73.08
12 Phosphorus (as P) 8.8 8.9 2.4 72.73 11.7 11.8 3.03 74.07
13 Oil & grease 38 38 37 2.63 38 38 37 2.63
14 H2 S 2.8 2.9 0.85 69.64 2.8 2.9 0.85 69.64
15 S V I 130 132 58 55.38 130 132 55 57.69
480
Table 66: 10% volume and 20% volume of plastic balls effect in
presence of 0.2% consortium and 12 hours HRT for
domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
Volume – 10% Volume – 20%
Before
treatm
ent
Blan
k
After
treatm
ent
(Mean)
%
Remov
al
(excep
t pH &
temp.)
Before
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remo
val
(excep
t pH
&
temp.)
1 pH 7.8 7.8 7.8 - 7.8 7.8 7.8 -
2 E.C 2260 2180 2030 10.18 2120 2080 1900.3 10.22
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 355 360 145.33 59.06 345 348 142 58.84
5 VSS 132 134 66 50.0 128 120 62.67 51.04
6 Chlorides 168 178 77.33 53.97 176 182 81.33 53.79
7 Hardness 360 350 251.33 30.19 380 360 263.67 30.61
8 Alkalinity 410 390 245.33 40.16 420 405 250 40.48
9 C O D 440 444 165 62.5 460 466 174.33 62.1
10 B O D 206 209 80.67 60.84 185 190 73 60.54
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
44.91
34.3
0.01
0.8
9.8
46.61
35.8
0.01
0.9
9.9
23.42
17.5
0.02
1.0
4.9
47.85
48.98
100.0
25.0
50.0
45.81
35.4
0.01
0.6
9.8
46.52
36.0
0.02
0.7
9.8
23.89
18.03
0.03
0.93
4.9
47.84
49.06
166.67
55.56
50.0
12 Phosphorus (as P) 10.8 10.9 5.1 52.78 9.6 9.8 4.6 52.08
13 Oil & grease 36 36 36 - 44 44 44 -
14 H2 S 2.7 2.8 1.2 55.56 2.8 2.9 1.2 57.14
15 S V I 115 120 85 26.09 112 120 80 28.57
481
Table 67: 30% volume and 40% volume of plastic balls effect in
presence of 0.2% consortium and 12 hours HRT for
domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Volume – 30% Volume – 40%
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.
)
Befor
e
treat
ment
Blan
k
Afte
r
trea
tme
nt
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 7.7 7.7 7.7 - 7.8 7.8 7.8 -
2 E.C 1980 1920 1780 10.10 2020 2000 1816.
6 10.07
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 340 344 140 58.82 315 321 129 59.05
5 VSS 138 130 87.67 36.47 128 160 64.33 49.74
6 Chlorides 145 148 67.33 53.56 146 152 65.67 55.02
7 Hardness 380 360 261 30.32 350 345 248.33 31.02
8 Alkalinity 430 415 258 40.0 410 390 246 40.0
9 C O D 510 516 191 62.55 460 466 172.33 62.54
10 B O D 204 208 79.67 60.95 198 199 77.67 60.77
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
43.22
32.4
0.02
1.2
9.6
43.93
33.1
0.03
1.2
9.6
23.07
16.8
0.04
1.43
4.8
46.62
48.15
83.33
19.44
50.0
43.82
33.6
0.02
1.0
9.2
44.72
34.3
0.02
1.1
9.3
23.07
17.1
0.04
1.33
4.6
47.35
49.11
100.0
33.33
50.0
12 Phosphorus (as P) 10.6 10.7 5.0 52.83 9.8 9.9 4.7 52.04
13 Oil & grease 40 40 40 - 38 38 38 -
14 H2 S 2.7 2.8 1.2 55.56 2.7 2.8 1.2 55.56
15 S V I 118 120 80 32.20 112 118 76 32.14
482
Table 68: 8 hours and 9 hours HRT effect along with 10%
volume of plastic balls and 0.2% consortium for
domestic sewage treatment
S.
N
o
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT @ 8 hours HRT @ 9hours
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(exce
pt pH
&
temp.
)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remo
val
(exce
pt pH
&
temp.
)
1 pH 7.8 7.8 7.8 - 7.6 7.6 7.6 -
2 E.C
2060 2020 1820 11.65 2030 2020 1823.
3 10.18
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 330 320 170 48.48 340 360 170 50.0
5 VSS 126 120 73 42.06 142 136 81 42.96
6 Chlorides 168 174 104 38.1 178 179 107 39.89
7 Hardness 360 350 280.33 22.13 345 330 265.33 23.09
8 Alkalinity 380 370 285 25.0 380 360 280.33 26.23
9 C O D 420 426 218.33 48.02 410 414 203 50.49
10 B O D 192 196 102.33 46.7 198 200 101.33 48.82
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
41.21
31.4
0.01
0.9
8.9
42.21
32.4
0.01
0.9
8.9
28.72
22.0
0.02
1.0
5.7
30.31
29.94
100.0
11.11
35.96
44.0
34.2
ND
0.9
8.9
45.01
35.0
0.01
1.0
9.0
29.35
22.57
0.02
1.07
5.7
33.29
34.02
18.52
35.96
12 Phosphorus (as P) 10.1 10.2 6.5 35.64 9.9 10.0 6.03 39.06
13 Oil & grease 32 32 32 - 38 38 38 -
14 H2 S 2.7 2.8 1.8 33.33 2.8 2.8 1.8 35.71
15 S V I 130 130 78 40.00 124 128 72 41.94
483
Table 69: 10 hours and 11 hours HRT effect along with 10%
volume of plastic balls and 0.2% consortium for
domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
HRT @ 10 hours HRT @ 11 hours
Before
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.
)
Befor
e
treat
ment
Blan
k
Afte
r
trea
tme
nt
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 7.6 7.6 7.6 - 7.7 7.7 7.7 -
2 E.C 2030 2000 1813.3 10.67 1990 1960 1800 9.55
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 320 326 153.3 52.08 330 336 152 53.94
5 VSS 142 136 78 45.07 152 142 80.33 47.15
6 Chlorides 180 186 102.33 43.15 160 164 83 48.13
7 Hardness 340 330 258 24.12 330 315 244 26.06
8 Alkalinity 360 340 255 29.17 370 345 248 32.97
9 C O D 390 392 183.33 52.99 405 408 178 56.05
10 B O D 180 184 88 51.11 188 194 86.33 54.08
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
43.61
33.2
0.01
0.8
9.6
44.31
33.9
0.01
0.8
9.6
26.87
20.25
0.02
0.9
5.7
38.39
39.01
100.0
12.5
40.63
47.82
37.2
0.02
1.0
9.6
48.62
38.0
0.02
1.0
9.6
27.77
21.2
0.04
1.17
5.37
41.94
43.01
100.0
16.67
44.10
12 Phosphorus (as P) 9.8 9.9 5.7 41.84 9.7 9.8 5.3 45.36
13 Oil & grease 42 42 42 - 40 40 40 -
14 H2 S 2.8 2.9 1.7 39.29 2.8 2.9 1.5 46.43
15 S V I 130 130 76 41.54 130 132 74 43.08
484
Table 70: 12 hours HRT effect along with 10% volume of plastic
balls and 0.2% consortium for domestic sewage
treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
HRT @ 12 hours
Before
treatment
Blank After
treatment
(Mean)
% Removal
(except pH
& temp.)
1 pH 7.7 7.7 7.6 0.1
2 E.C 1920 1900 1703.3 11.28
3 Temperature 27 27 27 -
4 TSS 345 352 142 58.84
5 VSS 128 136 64 50.0
6 Chlorides 168 172 75.33 55.16
7 Hardness 340 330 239 29.71
8 Alkalinity 430 410 259 39.77
9 C O D 460 464 172 62.61
10 B O D 168 192 73.33 60.99
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
45.22
35.4
0.02
1.0
8.8
46.12
36.2
0.02
1.0
8.9
23.71
18.07
0.04
1.2
4.4
47.57
48.96
100.0
20.0
50.0
12 Phosphorus (as P) 9.6 9.7 4.6 52.08
13 Oil & grease 40 40 40 -
14 H2 S 2.6 2.7 1.2 53.85
15 S V I 128 130 72 43.75
485
Table 71: 10 days and 20 days time period effect in domestic
sewage treatment along with 10% volume of
plastic balls, 0.2% consortium and 12 hours HRT
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH, electric
conductivity,
temperature &
SVI)
Time period – 10 days Time period – 20 days
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(exce
pt pH
&
temp.
)
Befo
re
treat
ment
Blan
k
Afte
r
treat
ment
(Me
an)
%
Remov
al
(except
pH &
temp.)
1 pH 7.8 7.8 7.7 0.1 8.0 8.0 7.9 0.1
2 E.C 1820 1790 1640 9.89 1920 1900 1730 9.9
3 Temperature 27 27 27 - 26 26 26 -
4 TSS 330 336 135.33 58.99 370 380 152 58.92
5 VSS 118 110 56.33 52.26 146 140 74.67 48.86
6 Chlorides 142 148 66.33 53.29 172 174 82.67 51.94
7 Hardness 340 330 238.67 29.8 340 330 238 30.0
8 Alkalinity 380 360 229.33 39.65 380 360 230 39.47
9 C O D 410 418 154 62.44 425 432 159.67 62.43
10 B O D 168 172 67.17 60.02 192 198 75.67 60.59
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
40.95
30.9
0.05
0.9
9.1
41.85
31.6
0.05
1.0
9.2
21.54
15.7
0.07
1.17
4.6
47.4
49.19
46.67
29.63
49.45
45.15
34.6
0.05
1.1
9.4
46.35
35.6
0.05
1.2
9.5
23.57
17.43
0.07
1.3
4.77
47.8
49.61
33.33
18.18
49.29
12 Phosphorus (as P) 9.8 9.8 4.7 52.04 9.2 9.4 4.4 52.17
13 Oil & grease 32 32 32 - 36 36 36 -
14 H2 S 2.6 2.7 1.2 53.85 2.7 2.8 1.2 55.56
15 S V I 128 130 70 45.31 130 134 70 46.15
486
Table 72: 30 days and 40 days time period effect in domestic
sewage treatment along with 10% volume of
plastic balls, 0.2% consortium and 12 hours HRT
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 30 days Time period – 40 days
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(excep
t pH
&
temp.
)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remo
val
(exce
pt pH
&
temp.
)
1 pH 7.6 7.6 7.6 - 7.7 7.7 7.63 0.07
2 E.C 1960 1910 1765 9.95 1900 1820 1710 10.0
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 385 392 158 58.96 360 366 148 58.89
5 VSS 140 130 70.67 49.52 148 140 74 50.0
6 Chlorides 172 178 77.33 55.04 158 162 71 55.06
7 Hardness 395 385 276 30.13 360 345 251.3
3 30.19
8 Alkalinity 410 390 245.67 40.08 410 400 247 39.76
9 C O D 430 434 161.33 62.48 480 484 180 62.5
10 B O D 184 188 71.33 61.23 196 198 74 62.24
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
4161
32.4
0.01
1.0
8.2
42.41
33.1
0.01
1.0
8.3
21.72
16.5
0.02
1.1
4.1
47.79
49.07
133.33
10.0
50.0
43.52
34.4
0.02
0.5
8.6
34.82
35.6
0.02
0.5
8.7
22.83
17.8
0.03
0.6
4.4
47.55
48.26
33.33
20.0
48.84
12 Phosphorus (as P) 9.8 9.9 4.7 52.04 9.4 9.5 4.4 53.19
13 Oil & grease 38 38 37 2.63 36 36 35.33 1.85
14 H2 S 2.6 2.7 1.13 56.41 2.7 2.8 1.2 55.56
15 S V I 130 130 70 46.15 124 130 66 46.77
487
Table 73: 50 days and 60 days time period effect in domestic
sewage treatment along with 10% volume of
plastic balls, 0.2% consortium and 12 hours HRT
S.
No
Physico-chemical
parameters
(All parameters
are expressed in
mg/litre (ppm)
except pH,
electric
conductivity,
temperature &
SVI)
Time period – 50 days Time period – 60 days
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mean
)
%
Remo
val
(exce
pt pH
&
temp.
)
Befor
e
treat
ment
Blan
k
After
treat
ment
(Mea
n)
%
Remo
val
(exce
pt pH
&
temp.
)
1 pH 7.8 7.8 7.8 - 7.8 7.8 7.8 -
2 E.C
2140 2100 1896.6 11.37 1920 1900 1706.
6 11.11
3 Temperature 27 27 27 - 27 27 27 -
4 TSS 320 324 131 59.06 370 380 148 60.0
5 VSS 140 130 70 50.0 148 143 74 50.0
6 Chlorides 178 182 80 55.06 168 168 77.33 53.97
7 Hardness 380 360 265 30.26 355 350 245 30.99
8 Alkalinity 420 400 250 40.08 460 440 271 41.09
9 C O D 490 496 183.33 62.59 490 496 183.33 62.59
10 B O D 202 204 81.67 59.57 202 202 80.67 61.07
11 T N
A N
Nitrite N (NO2-)
Nitrate N (NO3-)
Kjeldhal Nitrogen
49.22
38.3
0.02
1.1
9.8
50.12
39.1
0.02
1.1
9.9
25.73
19.5
0.03
1.2
5.0
47.72
49.09
50.0
9.09
48.98
46.65
36.3
0.05
1.4
8.9
47.55
37.1
0.05
1.4
9.0
24.93
18.87
0.06
1.5
4.5
46.57
48.03
20.0
7.14
49.44
12 Phosphorus (as P) 10.3 10.5 5.0 51.46 9.8 9.9 4.7 52.04
13 Oil & grease 34 34 33.33 1.96 36 36 35 2.78
14 H2 S 2.9 2.9 1.3 55.17 2.8 2.9 1.3 53.57
15 S V I 140 138 72 48.57 130 130 66 49.23
488
Table 74: Effect of granite stones as biofilter material with 10%
volume, 0.2% consortium and 12 hours HRT for 60
days time period for domestic sewage treatment
S.N
o
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH, electric
conductivity, temperature
& SVI)
Optimized study – Granite stones as biofilter
media
Before
treatment
Blank Mean % Removal
(except pH &
temperature)
1 pH 7.8 7.8 7.7 0.1
2 Electric conductivity 2060 2020 1670 18.93
3 Temperature 27 27 27 -
4 Total suspended solids 340 346 139 59.12
5 Volatile suspended solids 128 122 62.33 51.30
6 Chlorides 172 172 78.33 54.46
7 Hardness 385 360 262 31.95
8 Alkalinity 410 370 242 40.98
9 Chemical oxygen demand 420 422 151 64.05
10 Biochemical oxygen
demand 186 188 72 61.29
11 Total nitrogen
Ammonical nitrogen
Nitrite-nitrogen (NO2-)
Nitrate-nitrogen (NO3-)
Kjeldhal nitrogen
45.35
34.2
0.05
0.9
10.2
46.36
35.1
0.06
1.0
10.2
23.65
17.07
0.09
1.4
5.1
47.84
50.1
73.33
55.56
50.0
12 Phosphorus (as P) 10.4 10.5 4.9 52.88
13 Oil & grease 34 35 33 2.94
14 Hydrogen sulphide 2.8 2.8 0.9 67.86
15 Sludge volume index 124 128 78 37.10
489
Table 75: Effect of clay balls as biofilter material in domestic
sewage treatment with 30% volume, 0.2%
consortium and 10 hours HRT for 30 days time
period
S.N
o
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH, electric
conductivity, temperature
& SVI)
Optimized study – Clay balls as biofilter media
Before
treatment
Blank Mean % Removal
(except pH &
temperature)
1 pH 7.7 7.7 7.8 0.1
2 Electric conductivity 1880 1830 1503.3 20.04
3 Temperature 27 27 27 -
4 Total suspended solids 340 348 95.33 71.96
5 Volatile suspended solids 142 136 58 59.15
6 Chlorides 180 184 50.33 72.04
7 Hardness 315 303 159 49.52
8 Alkalinity 360 340 156.33 56.57
9 Chemical oxygen demand 390 396 106 72.82
10 Biochemical oxygen
demand 168 172 45.33 73.02
11 Total nitrogen
Ammonical nitrogen
Nitrite-nitrogen (NO2-)
Nitrate-nitrogen (NO3-)
Kjeldhal nitrogen
42.24
31.2
0.04
1.2
9.8
43.55
32.4
0.05
1.2
9.9
15.83
10.97
0.09
1.57
3.2
62.53
64.85
133.33
30.56
67.35
12 Phosphorus (as P) 10.2 10.3 3.3 67.65
13 Oil & grease 38 38 36.67 3.51
14 Hydrogen sulphide 2.8 2.8 0.95 66.07
15 Sludge volume index 110 110 70 36.36
490
Table 76: Effect of sintered glass cylinders as biofilter material
with 30% volume, 0.2% consortium and 10 hours
HRT for 30 days time period for domestic sewage
treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH,
electric conductivity,
temperature & SVI)
Optimized study – Sintered glass cylinders
as biofilter media
Before
treatment
Blank Mean % Removal
(except pH
&
temperature
)
1 pH 7.8 7.8 7.8 -
2 Electric conductivity 1960 1910 1570 19.9
3 Temperature 27 27 27 -
4 Total suspended solids 328 332 92 71.95
5 Volatile suspended
solids 138 130 56.33 59.18
6 Chlorides 168 174 50 70.24
7 Hardness 318 300 156 50.94
8 Alkalinity 440 415 189 57.05
9 Chemical oxygen
demand 410 416
115.3
3 71.87
10 Biochemical oxygen
demand 172 178 46.33 73.06
11 Total nitrogen
Ammonical nitrogen
Nitrite-nitrogen (NO2-)
Nitrate-nitrogen (NO3-)
Kjeldhal nitrogen
45.82
34.6
0.02
1.1
10.1
47.02
35.6
0.02
1.2
10.2
17.09
12.10
0.06
1.53
3.4
62.69
65.03
200.0
39.39
66.34
12 Phosphorus (as P) 10.6 10.8 3.47 67.30
13 Oil & grease 32 32 31 3.13
14 Hydrogen sulphide 2.8 2.9 0.95 66.07
15 Sludge volume index 120 120 78 35.0
491
Table 77: Effect of corn cobs as biofilter material in domestic
sewage treatment with 20% volume, 0.2%
consortium and 9 hours HRT for 40 days time
period
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH, electric
conductivity, temperature
& SVI)
Optimized study – Corn cobs as biofilter media
Before
treatment
Blank Mean % Removal
(except pH &
temperature)
1 pH 7.8 7.8 7.8 -
2 Electric conductivity 1980 1890 1560 21.21
3 Temperature 26 26 26 -
4 Total suspended solids 348 352 59 83.05
5 Volatile suspended solids 144 136 44 69.44
6 Chlorides 174 178 48.33 72.22
7 Hardness 310 300 105.33 66.02
8 Alkalinity 360 330 119 66.94
9 Chemical oxygen demand 390 396 68.33 82.48
10 Biochemical oxygen
demand 176 182 26.33
85.04
11 Total nitrogen
Ammonical nitrogen
Nitrite-nitrogen (NO2-)
Nitrate-nitrogen (NO3-)
Kjeldhal nitrogen
43.91
33.2
0.01
1.2
9.5
45.02
34.2
0.02
1.2
9.6
13.07
8.9
0.04
1.63
2.5
70.23
73.19
300.0
36.11
73.68
12 Phosphorus (as P) 10.2 10.4 2.6 74.51
13 Oil & grease 32 32 30 6.25
14 Hydrogen sulphide 2.9 2.9 0.7 75.86
15 Sludge volume index 140 138 62 55.71
492
Table 78: Effect of wood chips as biofilter material with 30%
volume, 0.2% consortium and 10 hours HRT for
50 days time period for domestic sewage
treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH, electric
conductivity, temperature
& SVI)
Optimized study – Wood chips as biofilter
media
Before
treatment
Blank Mean % Removal
(except pH &
temperature)
1 pH 7.8 7.8 7.7 0.1
2 Electric conductivity 2220 2180 1730 22.07
3 Temperature 27 27 27 -
4 Total suspended solids 330 336 57.67 82.53
5 Volatile suspended solids 145 140 46.67 67.82
6 Chlorides 164 168 51 68.9
7 Hardness 330 320 118.67 64.04
8 Alkalinity 380 360 129 66.05
9 Chemical oxygen demand 410 414 72 82.44
10 Biochemical oxygen
demand 172 178 28.33 83.53
11 Total nitrogen
Ammonical nitrogen
Nitrite-nitrogen (NO2-)
Nitrate-nitrogen (NO3-)
Kjeldhal nitrogen
44.82
34.2
0.02
1.2
9.4
46.33
35.6
0.03
1.2
9.5
14.13
9.9
0.06
1.47
2.7
68.48
71.05
200.0
22.22
71.28
12 Phosphorus (as P) 9.9 10.0 2.7 72.73
13 Oil & grease 36 36 34 5.56
14 Hydrogen sulphide 2.8 2.8 0.8 71.43
15 Sludge volume index 130 130 66 49.23
493
Table 79: Effect of nylon threads as biofilter material in
domestic sewage treatment in presence of 30%
volume, 0.2% consortium and 9 hours HRT for
60 days time period
S.N
o
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH, electric
conductivity, temperature
& SVI)
Optimized study – Nylon threads as biofilter
media
Before
treatment
Blank Mean % Removal
(except pH &
temperature)
1 pH 7.8 7.8 7.7 0.1
2 Electric conductivity 2160 2080 1680 22.22
3 Temperature 27 27 27 -
4 Total suspended solids 345 348 65 81.16
5 Volatile suspended solids 132 136 37 71.97
6 Chlorides 172 174 46.33 73.06
7 Hardness 360 350 122 66.11
8 Alkalinity 380 380 125.33 67.02
9 Chemical oxygen demand 390 394 70.67 81.88
10 Biochemical oxygen
demand 180 182 27 85.0
11 Total nitrogen
Ammonical nitrogen
Nitrite-nitrogen (NO2-)
Nitrate-nitrogen (NO3-)
Kjeldhal nitrogen
44.11
33.4
0.01
0.8
9.9
44.72
33.9
0.02
0.9
9.9
12.92
9.07
0.05
1.2
2.6
70.72
72.85
400.0
50.0
73.74
12 Phosphorus (as P) 10.8 10.9 2.8 74.07
13 Oil & grease 34 34 32.33 4.9
14 Hydrogen sulphide 2.8 2.8 0.95 66.07
15 Sludge volume index 128 130 60 53.13
494
Table 80: Effect of plastic balls as biofilter material with 10%
volume, 0.2% consortium and 12 hours HRT for
60 days time period for domestic sewage treatment
S.
No
Physico-chemical
parameters
(All parameters are
expressed in mg/litre
(ppm) except pH, electric
conductivity, temperature
& SVI)
Optimized study – Plastic balls as biofilter
media
Before
treatment
Blank Mean % Removal
(except pH &
temperature)
1 pH 7.8 7.8 7.7 0.1
2 Electric conductivity 1820 1800 1600 12.09
3 Temperature 27 27 27 -
4 Total suspended solids 370 376 148.33 59.91
5 Volatile suspended solids 148 140 73.33 50.45
6 Chlorides 168 168 77.33 53.97
7 Hardness 340 330 234.33 31.08
8 Alkalinity 370 350 218 41.08
9 Chemical oxygen demand 415 418 153.67 62.97
10 Biochemical oxygen
demand 192 194 76.67 60.07
11 Total nitrogen
Ammonical nitrogen
Nitrite-nitrogen (NO2-)
Nitrate-nitrogen (NO3-)
Kjeldhal nitrogen
45.15
35.6
0.05
1.1
8.4
45.55
35.9
0.05
1.1
8.5
24.17
18.5
0.07
1.4
4.2
46.47
48.03
40.0
27.27
50.0
12 Phosphorus (as P) 9.4 9.5 4.5 52.13
13 Oil & grease 36 36 35.67 0.93
14 Hydrogen sulphide 2.8 2.8 1.3 53.57
15 Sludge volume index 130 130 68 47.69
495
Table 81: Effect of various filter media on food to
microorganism (F/M) ratio during the treatment
of domestic sewage
S.No Filter
material
Physico-chemical parameter F/M ratio
BOD VSS Before After
Before After Before After
1 Granite
stone 186 72.0 128 62.33 1.45 1.16
2 Clay
ball 168 45.33 142 58.0 1.18 0.78
3
Sintered
glass
cylinder
172 46.33 138 56.33 1.25 0.82
4 Corn
cob 176 26.33 144 44.0 1.22 0.6
5 Wood
chip 172 28.33 145 46.67 1.19 0.61
6 Nylon
thread 180 27.0 132 37.0 1.36 0.73
7 Plastic
ball 192 76.67 148 73.33 1.30 1.05
496
Table 82: Rf values of proteins extracted from molecular
marker, biofilm, consortium, raw sewage and
treated sewage in SDS PAGE
Marker Biofilm Consortium Raw
sewage
Treated
sewage
Lane 1 Lane 2 Lane 3 Lane 4 Lane 5
0.178 0.103 0.097 0.103 0.838
0.232 0.157 0.157 0.173
0.308 0.346 0.227 0.243
0.427 0.47 0.346 0.368
0.595 0.53 0.465 0.481
0.908 0.643 0.514 0.551
0.692 0.632 0.589
0.854 0.827 0.708
0.978
0.746
0.816
0.865
0.968
497
Table 83: Molecular Weight values of samples
Marker
Biofilm Consortium
Raw
sewage
Treated
sewage
Lane 1 Lane 2 Lane 3 Lane 4 Lane 5
116 247 263 247 24
66 140 140 120
45 36 74 65
35 27 36 33
25 25 27 26
18 24 26 25
24 24 25
24 24 24
24
24
24
24
24
498
Image 1: Sample collection at sewage treatment plant, vijayawada
499
Image2 : Surface area calculation of corn cob
Surface area of Corncob cavity:
It is a inverted trapezoid having 4 sides (front, back and
two laterals) and 1 base.
Surface area of front side: A = (b1+b2) x h
2
8mm
6
mm
6mm
6 mm
2 mm
2 mm
mm
4 mm
6 mm
500
6+8/2 x 6 = 42 mm2
Backside = 42 mm2
Lateral side1 = 2+6/2 x 6 = 24 mm2
Lateral side2 = 24 mm2
Base: lx b = 2x4 = 8 mm2
Total surface area of each cavity = 42+42+24+24+8 =
140 mm2
Top surface area has to be deducted from hollow
cylindrical cone: 8mm x 6 mm (LxB) = 48 mm2
Cob sample
3 7
4 9
5 11
6 14
7 16
25/5=5 57/5=11.4
3 7
4 9
5 11
6 14
7 16
25/5=5 57/5=11.4
3 7
4 10
5 13
6 16
7 18
25/5=5 64/5=12.8
501
Std. deviation =0.954
Hence each centimeter of corn cob contains 2.416
cavities on length basis.
5 cm length was selected.
For 5 cm length and 2.5 cm OD cob contains 5 x 2.41
cavities and each row contains 14 cavities hence total =
168.7 cavities on average.
Hollow cylindrical cone:
2∏rh+ 2∏Rh+ 2(∏R2 - ∏r
2)
(2x3.14x5x50) + (2 x 3.14x 12.5x50)+2(3.14 (12.5) 2
–
3.14 (5) 2
)
= 1570 + 3925+824.24 = 6319.24 mm2 = 63.19cm
2
3 9
4 11
5 13
6 16
7 18
25/5=5 67/5=13.4
3 7
4 9
5 11
6 14
7 16
25/5=5 57/5=11.4
1 11.4
2 11.4
3 12.8
4 11.4
5 13.4
502
Total surface area of 5 cm x 2.5 dia corn cob =
(Surface area of no. of cavities + surface area of total
cob) - (Surface area of top of each cavity)
= 168.7 x 140 mm2 + 6319.24 – (48mm
2 x 168.7)
= 23618 mm2 + 6319.24 – 8097.6 mm
2
= 21839.64 mm2
= 218.39 cm2
If the length of the cob is 7.6 cm then surface area is
327.68 cm2.
503
Image 3: Unprocessed natural biofilter material – granite stones
504
Image 4: Processed natural biofilter material – clay balls
4 cm
505
2.6 cm
Image 5: Natural processed biofilter material – sintered glass cylinders
506
Image 6: Biogenic biofilter material – corn cobs
Image 7: Biofiltration system setup using corn cobs as biofilter
material
507
Image 8: Biogenic biofilter material – wood chips
0.8 cm (b)
8.4 cm (l) 0.7 cm (h)
508
Image 9: Synthetic biofilter material – nylon threads
509
Image 10: Synthetic biofilter material – plastic balls
3.6 cm
510
Fig.1: Concentration effect of microbial consortium
on pollutant removal efficiency
0
10
20
30
40
50
60
70
80
0.05 0.1 0.2 0.3 0.4 0.5
% o
f re
mo
va
l ef
fici
ency
of
po
llu
tan
ts
% of inoculum
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
511
Fig.2: Hydraulic retention time (HRT) effect on
pollutant removal efficiency
0
10
20
30
40
50
60
70
4 8 12 16 20 24% o
f re
mo
va
l ef
fici
ency
of
po
llu
tan
ts
HRT in hours
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
512
Fig.3: Volume % effect on removal efficiency of
pollutants in presence of granite stones as
biofilter material, 0.2% inoculum and 12
hours HRT
46
48
50
52
54
56
58
60
62
64
10 20 30 40
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Volume in %
Total suspended solids Chemical oxygen demandBiochemical oxygen demand Total nitrogenPhosphorus (as P) Hydrogen sulphide
513
Fig.4: HRT effect on removal efficiency of pollutants
in presence of 10% volume of granite stones
as biofilter material, 0.2% inoculum
0
10
20
30
40
50
60
70
8 9 10 11 12
% o
f re
mo
va
l ef
fici
ency
of
po
llu
tan
ts
HRT in hours
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
514
Fig.5: Time period effect on removal efficiency of
pollutants in presence of 10% volume of
granite stones as biofilter material, 0.2%
inoculum & 12 hours HRT
0
10
20
30
40
50
60
70
10 20 30 40 50 60
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Time period in days
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
515
Fig.6: Effect of % of volume on removal efficiency of
pollutants in presence of clay balls as biofilter
material, 0.2% inoculum & 12 hours HRT
0
10
20
30
40
50
60
70
80
10 20 30 40
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Volume in %
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
516
Fig.7: HRT effect on removal efficiency of pollutants
in presence of 30% volume of clay balls as
biofilter material & 0.2% inoculum
0
10
20
30
40
50
60
70
80
8 9 10 11 12
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Hydraulic retention time in hours
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
517
Fig.8: Time period effect on removal efficiency of
pollutants in presence of 30% volume of clay
balls as biofilter material & 0.2% inoculum
and 10 hours HRT
0
10
20
30
40
50
60
70
80
10 20 30 40 50 60% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Time period in days
Total suspended solids
Chemical oxygen demand
Biochemical oxygen demand
518
Fig.9: Effect of % of volume on removal efficiency of
pollutants in presence of sintered glass
cylinders as biofilter material & 0.2%
inoculum and 12 hours HRT
0
10
20
30
40
50
60
70
80
10 20 30 40% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
% of volume
Total suspended solids Chemical oxygen demandBiochemical oxygen demand Total nitrogenPhosphorus (as P) Hydrogen sulphide
519
Fig.10: HRT effect on removal efficiency of pollutants
in presence of 30% volume of sintered glass
cylinders as biofilter material & 0.2%
inoculums
0
10
20
30
40
50
60
70
80
8 9 10 11 12% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
HRT in hours
Total suspended solids Chemical oxygen demandBiochemical oxygen demand Total nitrogenPhosphorus (as P) Hydrogen sulphide
520
Fig.11: Time period effect on removal efficiency of
pollutants in presence of 30% volume of
sintered glass cylinders as biofilter material,
0.2% inoculum & 10 hours HRT
0
10
20
30
40
50
60
70
80
10 20 30 40 50 60% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Time period in days
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
521
Fig.12: Effect of % of volume on removal efficiency
of pollutants in presence of corn cobs as
biofilter material, 0.2% inoculum & 12 hours
HRT
0
10
20
30
40
50
60
70
80
90
10 20 30 40% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Volume in %
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
522
Fig.13: HRT effect on removal efficiency of pollutants
in presence of 20% volume of corn cobs as
biofilter material & 0.2% inoculum
0
10
20
30
40
50
60
70
80
90
8 9 10 11 12
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
HRT in hours
Total suspended solids Chemical oxygen demandBiochemical oxygen demand Total nitrogenPhosphorus (as P) Hydrogen sulphide
523
Fig.14: Time period effect on removal efficiency of
pollutants in presence of 20% volume of corn
cobs as biofilter material, 0.2% inoculum & 9
hours HRT
0
10
20
30
40
50
60
70
80
90
10 20 30 40 50 60
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Time period in days
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
524
Fig.15: Effect of % of volume on removal efficiency
of pollutants in presence of wood chips as
biofilter material, 0.2% inoculum & 12 hours
HRT
0
10
20
30
40
50
60
70
80
90
10 20 30 40% o
f ef
fici
ent
rem
ov
al
of
po
llu
tan
ts
Volume in %
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
525
Fig.16: HRT effect on removal efficiency of pollutants
in presence of 30% volume of wood chips as
biofilter material & 0.2% inoculum
0
10
20
30
40
50
60
70
80
90
8 9 10 11 12
% o
f ef
fici
ent
rem
ov
al
of
po
llu
tan
ts
HRT in hours
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
526
Fig.17: Time period effect on removal efficiency of
pollutants in presence of 30% volume of
wood chips as biofilter material, 0.2%
inoculum & 10 hours HRT
0
10
20
30
40
50
60
70
80
90
10 20 30 40 50 60
% o
f ef
fici
ent
rem
ov
al
of
po
llu
tan
ts
Time period in days
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
527
Fig.18: Effect of % of volume on removal efficiency
of pollutants in presence of nylon threads as
biofilter material, 0.2% inoculum & 12 hours
HRT
0
10
20
30
40
50
60
70
80
90
10 20 30 40
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Volume in %
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
528
Fig.19: HRT effect on removal efficiency of pollutants
in presence of 30% volume of nylon threads
as biofilter material & 0.2% inoculum
0
10
20
30
40
50
60
70
80
90
8 9 10 11 12
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
HRT in hours
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
529
Fig.20: Time period effect on removal efficiency of
pollutants in presence of 30% volume of
nylon threads as biofilter material, 0.2%
inoculum & 9 hours HRT
0
10
20
30
40
50
60
70
80
90
10 20 30 40 50 60
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Timer period in days
Total suspended solids Chemical oxygen demandBiochemical oxygen demand Total nitrogenPhosphorus (as P) Hydrogen sulphide
530
Fig.21: Effect of % of volume on removal efficiency
of pollutants in presence of plastic balls as
biofilter material, 0.2% inoculum & 12 hours
HRT
0
10
20
30
40
50
60
70
10 20 30 40
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Volume in %
Total suspended solids Chemical oxygen demandBiochemical oxygen demand Total nitrogenPhosphorus (as P) Hydrogen sulphide
531
Fig.22: HRT effect on removal efficiency of pollutants
in presence of 10% volume of plastic balls as
biofilter material & 0.2% inoculum
0
10
20
30
40
50
60
70
8 9 10 11 12
% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
HRT in hours
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
532
Fig.23: Time period effect on removal efficiency of
pollutants in presence of 10% volume of
plastic balls as biofilter material, 0.2%
inoculum & 12 hours HRT
0
10
20
30
40
50
60
70
10 20 30 40 50 60% o
f ef
fici
ency
rem
ov
al
of
po
llu
tan
ts
Time period in days
Total suspended solids Chemical oxygen demand
Biochemical oxygen demand Total nitrogen
Phosphorus (as P) Hydrogen sulphide
533
Fig.24: Variations in pH in the presences of various
filter media during the sewage treatment
process
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
pH
Filter Media
534
Fig.25: Electric conductivity variations with various
filter media during the sewage treatment
process
0
5
10
15
20
25
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
Ele
ctri
c co
nd
uct
ivit
y i
n m
Mh
os/
cm2
Filter Media
535
Fig. 26: Effect of various filter media on removal
efficiency of total suspended solids
0
10
20
30
40
50
60
70
80
90
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball% o
f ef
fici
ency
rem
ov
al
of
tota
l su
spen
ded
soli
ds
Filter Media
536
Fig. 27: Filter media effect on removal efficiency of
volatile suspended solids
0
10
20
30
40
50
60
70
80
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball% o
f eff
icie
ncy
rem
ov
al
of
vo
lati
le s
usp
end
ed
soli
ds
Filter Media
537
Fig. 28: Removal efficiency of chlorides in presence of
various filter media
0
10
20
30
40
50
60
70
Stone Clay ball Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
chlo
rid
es
Filter Media
538
Fig. 29: Hardness removal efficiency with various
filter media
0
10
20
30
40
50
60
70
Stone Clay ball Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
ha
rdn
ess
Filter Media
539
Fig. 30: Alkalinity removal efficiency in presence of
various filter media
0
10
20
30
40
50
60
70
80
Stone Clay ball Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
alk
ali
nit
y
Filter Media
540
Fig. 31: Chemical oxygen demand elimination
efficiency of various filter media
0
10
20
30
40
50
60
70
80
90
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
chem
ica
l
oxy
gen
dem
an
d
Filter Media
541
Fig. 32: Effect of various filter media on removal
efficiency of biochemical oxygen demand
0
10
20
30
40
50
60
70
80
90
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
Bio
-ch
emic
al
oxy
gen
dem
an
d
Filter Media
542
Fig. 33: Total nitrogen removal efficiency of various
filter media
0
10
20
30
40
50
60
70
80
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
tota
l n
itro
gen
Filter media
543
Fig. 34: Ammonical nitrogen removal by various
filter media
0
10
20
30
40
50
60
70
80
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball% o
f eff
icie
ncy
rem
ov
al
of
am
mo
nic
al
nit
ro
gen
Filter media
544
Fig. 35: Nitrite nitrogen removal by various filter
media
-450
-400
-350
-300
-250
-200
-150
-100
-50
0
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f eff
icie
ncy
rem
ov
al
of
nit
rit
e n
itro
gen
Filter media
545
Fig. 36: Nitrate nitrogen removal by various filter
media
-60
-50
-40
-30
-20
-10
0
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f eff
icie
ncy
rem
ov
al
of
nit
ra
te-n
itro
gen
Filter media
546
Fig. 37: Kjeldhal nitrogen removal by various filter
media
0
10
20
30
40
50
60
70
80
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
kje
ldh
al-
nit
rog
en
Filter media
547
Fig. 38: Effect of various filter media on removal
efficiency of phosphorus
0
10
20
30
40
50
60
70
80
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
ph
osp
ho
rus
Filter media
548
Fig. 39: Oil & grease removal efficiency of various
filter media
0
1
2
3
4
5
6
7
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
oil
& g
rea
se
Filter media
549
Fig.40: Hydrogen sulphide removal efficiency of
various filter media
0
10
20
30
40
50
60
70
80
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
hy
dro
gen
su
lph
ide
Filter media
550
Fig.41: Sludge volume index removal efficiency of
various filter media
0
10
20
30
40
50
60
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
% o
f ef
fici
ency
rem
ov
al
of
slu
dg
e v
olu
me
ind
ex
Filter media
551
Fig.42: Effect of volume of biofilter materials on
removal efficiency of biochemical oxygen
demand
0
10
20
30
40
50
60
70
80
90
10% 20% 30% 40%
% o
f ef
fici
ency
rem
ov
al
of
bio
chem
ica
l o
xy
gen
dem
an
d
% of filter material
Stone Clay ballSintered glass cylinder Corn cobWood chip Nylon threadplastic ball
552
Fig.43: Hydraulic retention time effect in presence of
biofilter materials on removal efficiency of
biochemical oxygen demand
0
10
20
30
40
50
60
70
80
90
8 9 10 11 12
% o
f ef
fici
ency
rem
ov
al
of
Bio
chem
ica
l O
xy
gen
Dem
an
d
HRT in hours
Stone Clay ballSintered glass cylinder Corn cobWood chip Nylon thread
553
Fig.44: Time period effect in removal efficiency of
biochemical oxygen demand along with
various biofilter materials
0
10
20
30
40
50
60
70
80
90
10 20 30 40 50 60
% o
f ef
fici
ency
rem
ov
al
of
Bio
chem
ica
l O
xy
gen
Dem
an
d
Time Period in days
Stone Clay ball
Sintered glass cylinder Corn cob
Wood chip Nylon thread
554
Fig.45: Effect of various filter media on food to
microbe ratio
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
Stone Clay
ball
Sintered
glass
cylinder
Corn
cob
Wood
chip
Nylon
thread
Plastic
ball
F/M
Ra
tio
Filter Media
Before After
555
Fig. 46: Surface of corn cob showing bacterial species
at 1000 X
556
Fig. 47: Bacterial species at 8000 X on the surface of
corn cob
557
Fig.48: Various species of bacteria on the surface of
corn cob at 10000 X
558
Fig.49: Bacterial species on the surface of nylon
thread at 3000 X
559
Fig.50: Surface of nylon thread showing bacterial
species at 6000 X
560
Fig.51: Bacterial species on the surface of nylon
thread at 10000 X
561
Fig.52: Biofilm on corn cobs
562
Fig.53: Biofilm formation on nylon threads
563
Fig.54: Matrix of corn cob
564
Fig.55: Surface of Nylon thread
565
Figure 56: SDS-PAGE of proteins from biofilm,
consortium, raw sewage and treated sewage
Lane 1: molecular weight markers,
Lane 2: proteins from biofilm,
Lane 3: proteins from consortium used for treatment,
Lane 4: proteins from raw/untreated sewage and
Lane 5: proteins from treated sewage
566
Fig.57: Rf values of proteins extracted from
molecular marker, biofilm, consortium, raw
sewage and treated sewage in SDS PAGE
567
Fig.58: Mass spectrum of protein sample from raw
sewage in positive mode
568
Fig.59: Mass spectrum of protein sample from raw
sewage in negative mode
569
Fig.60: Treated sewage sample mass spectrum in
positive mode
570
Fig.61: Treated sewage sample mass spectrum in
negative mode
571
Fig.62: Mass spectrum of protein sample from
consortium in positive mode
572
Fig.63: Mass spectrum of protein sample from
consortium in negative mode
573
Fig.64: Mass spectrum of protein sample from
biofilm in positive mode
574
Fig.65: Mass spectrum of protein sample from
biofilm in negative mode
Recommended