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Lake 2008 : Conservation and Management of River and Lake Ecosystem
BASELINE STUDY OF AN
River and Lake Ecosystem Dates : 22nd- 24th December 2008
Venue : Satish Dhawan Auditorium, Indian Institute of Science, Bangalore 560 012
BASELINE STUDY OF AN ECO-RESTORATION PROCESS ON A
HYPER-EUTROPHIC URBAN WATER BODYHYPER EUTROPHIC URBAN WATER BODYY. Prathishta, JRF, CES, Anna University, Chennai
Dirk Walther, CIM expert, CES, Anna University, ChennaiK. Thanasekaran, Director, CES, Anna University, Chennai, , , y,
ContentsY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Contents
Obj ti & Sit S l ti• Objectives & Site Selection
R t ti t h i• Restoration techniques
Eff t f t t t• Effect of treatment
C l i• Conclusion
IntroductionY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
• Ramsar convention, 1971.
I di 15 illi b di 25 R i• India – 15 million water bodies, 25 Ramsar sites.
• “The National Lake Conservation Plan” (1994) and “TheNational Wetland Conservation Programme” (1995)National Wetland Conservation Programme (1995).
• “Wetland (Conservation and Management) rules 2008”.
• Hypereutrophic pond for the study.
• Technologies used for restoring the pond.
• Utilize the pond for propagation of wildlife.
ObjectivesY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
jThe scope of the project is to developefficient eco-restoration mechanism in a
ll l h d hsmall scale eutrophic pond to reacholigotrophic state
• To Monitor the status of the pond by conducting Physico chemical and biological conducting Physico-chemical and biological analysis.
• Technologies to be urged for rejuvenating the pond by enhancing the oxygen loads the pond by enhancing the oxygen loads and maintaining the mass balance.
Study Area & Sampling Y. Prathishta, Dirk Walther, K. Thanasekaran (2008)
pStrategy
• The pond is located at Besant Nagar (Chennai, Tamil Nadu)
S.No
Frequency of sampling
Type of sampling
1. Before the t ti
Integrated li Tamil Nadu)
• Area - 2,452.8 m2
• Depth -1.6m l l 924 3
restoration process
sampling (H)
2. Aquatic h t
Integrated s li • Total Volume - 3,924 m3
• The pond was overgrown with (Pistia spp.) water
macrophyte removal
sampling (V)
3. During the filtering process
Integrated sampling ( pp )
cabbagesfiltering process sampling
(V)
V - VerticalV VerticalH - Horizontal
Sampling Sites
Y. Prathishta, Dirk Walther, K. Thanasekaran (2008)
DC
B
Sampling Sites 1.85 m
1.89 m
AE
C
1.71 m
1.9 m
2.5 m
Dissolved Oxygen(DO) Profiling with depth
DO in mg/L
0
0.2
0.4
0 1 2 3 4 5 6
DO in mg/L
0.6
0.8
1
1.2
Dep
th in
m
1.4
1.6
Site 'A' Site 'B' Site 'C' Site 'D' Site 'E'
MethodologyY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Pond
Aquatic macrophyte
removalStep 1 Reduces nutrient
concentration
Filtration and re-aerationStep 2 Accelerates and re-aerationStep 2
removes nutrients
Aquatic macrophyte removalY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Aquatic macrophyte removal
Filtration and Re-aeration set upY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Filtration and Re aeration set up
Impacts of RestorationY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Impacts of RestorationBefore
restoration
E i E i M t
After water cabbage removal
During filtration
P t U it M t H E i HEpi- Epi- Meta-limnion limnion limnion
1 pH - 7.1 8.8 7.7 7.7 8.3 7.9 7.62 EC µS/cm 1390 957 950 954 381 375 3743 DO mg/L 3.2 4.4 3 1.2 4.8 3.9 1.9
Parameters Units Meta-limnion
Hypo-limnion
Epi-limnion
Hypo-limnion
S. No
g4 Temp ºC 24.7 30.6 29.5 29.2 31.1 29.2 29.15 TDS mg/L 922 1180 1250 1090 1283 1093 12876 TSS mg/L 131 257 149 210 140 1200 13957 TS mg/L 1050 1440 1200 1370 1423 107 1088 T bidit NTU 14 9 120 30 69 1 28 9 17 2 17 78 Turbidity NTU 14.9 120 30 69.1 28.9 17.2 17.79 NH4-N mg/L 15.4 BDL BDL BDL 1.4 0.8 1.1
10 NO2-N mg/L BDL BDL BDL BDL BDL BDL BDL11 NO3-N mg/L BDL 0.1 0.1 0.1 BDL BDL BDL12 TKN N /L 23 8 9 8 7 4 2 9 8 4 2 4 212 TKN-N mg/L 23.8 9.8 7 4.2 9.8 4.2 4.213 Chlorophyll a mg/m3 80.5 39 13.9 1.1 371 21.3 17.114 PO4
3- P mg/L 1.1 0.4 0.5 0.3 1.4 0.9 0.915 COD mg/L 168 96 92 86 45 45 9416 BOD (20ºC) /L 52 30 27 23 14 14 2816 BOD5(20ºC) mg/L 52 30 27 23 14 14 2817 Fecal coliform MPN/100ml 1.13*105 2.33*105 1.13*104 7.79*104 6.79*104 3.79*104 5.02*104
18 Total coliform MPN/100ml 1.13*105 1.13*105 6.79*103 5.22*104 5.02*104 1.13*104 3.79*104
Y. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Changes during restorationChange in water quality during restoration in metalimnionChange in water quality during restoration in epilimnion
3
7
0 5
3.9
0.8
4.2
0.91
234
56
78
conc
entr
atio
n in
mg/
L
3.2
15.4
23.8
4.4
9.8
4.8
9.8
5
10
15
20
25
once
ntra
tion
in m
g/L
0.150.5
01
DO NH4-N TKN PO43—P
parameters
c
after w ater cabbage removal during f iltration
3.21.10.15 0.41.4 1.4
0
5
DO NH4-N TKN PO43—P
parameters
c
before restoration after w ater cabbage removal during f iltration
Change in water quality during restoration in metalimnion
92
4360708090
100
on in
mg/
L
Change in water quality during restoration in epilimnion
371
250
300
350
400
n m
g/L
27
13.914
43
21.3
01020304050
BOD COD chlorophyll a
parameters
conc
entr
atio
after w ater cabbage removal during f iltration
52
168
80.5
30
96
3914
45
0
50
100
150
200
250
BOD COD chlorophyll a
parameters
conc
entr
atio
n in
after w ater cabbage removal during f iltrationbefore restoration after w ater cabbage removal during f iltration
Changes during restorationY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Changes during restoration
Change in water quality during restoration in hypolimnion
1.2
4.2
0 3
1.9
1.1
4.2
0.91
1.52
2.53
3.54
4.5
once
ntra
tion
in m
g/L
DO profiling with depth
0 000 2 4 6 8
DO in mg/L
0.1 0.3
00.5
DO NH4-N TKN PO43—P
parameters
co
after w ater cabbage removal during f iltration
0.00
0.25
0.50
0 75m
Change in water quality during restoration in hypolimnion
86
94
60708090
100
n in
mg/
L
0.75
1.00
1.25
1.50
Dep
th in
m23
1.1
28
17.1
01020304050
BOD COD chlorophyll a
parameters
conc
entr
atio
f bb l d i fil i
1.75
2.00A E C D B
after water cabbage removal during filtration
DO increaseY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Production of oxygen during re-aerationFl 5 L/
DO increase
• Flow rate = 5 L/s• Volume of water per hour = 18 cubic meter• DO level in the pond = 0.79 mg/L• DO level in the outlet = 4 93 m/L• DO level in the outlet = 4.93 m/L• DO production in the outlet = 4.14 mg/L or 4.14g/m3
• Filtration process = 23.8 kg of O2
BOD reduction during aeration
• After water cabbage removal = 97.9 kg of BODf g g f• During filtration = 69 kg of BOD• Reduction of BOD = 28.9 kg of BOD• Reduction percentage = 30%
Effect of TreatmentY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Effect of Treatment
Trophic Level IndexY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
pTrophic state
Nutrient enrichment category
Trophic Level Chla (mg/m3)
Secchi depth (m)
TP (mg/m3)
TN(mg/m3)
Ultramicro-trophic
Practically Pure 0.0 to 1.0 < 0.33 >25 < 1.8 <34
Micro- Very Low 1 0 to 2 0 0.33- 25 15 1.8- 34 73trophic Very Low 1.0 to 2.0 0.82 25-15 4.1 34-73
Oligo-trophic Low 2.0 to 3.0 0.82 -
2.0 15 - 7 4.1-9.0 73-157
Meso-trophic Medium 3.0 to 4.0 2 - 5 7-2.8 9 - 20 157-337
Eutrophic High 4.0 to 5.0 5 - 12 2.8-1 1 20-43 337-7251.1
Super-trophic Very High 5.0 to 6.0 12 - 31 1.1-
0.4 43-96 725-1558
HyperHyper-trophic Saturated > 6.0 > 31 < 0.4 > 96 > 1558
Source: Rotorua (2002)
Status of the PondY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Layers Chl a (mg/m3) OP (mg/m3)* TN (mg/m3) SD (m)
Epilimnion (BR) 80.5 1100 23800 1.01
Epilimnion (AMR) 39.0 400 9800 0.74
Metalimnion (AMR) 13.9 500 7000 0.86
Hypolimnion (AMR) 1.1 300 4200 0.77
E ili i (DF) 371 0 1400 9800 0 86Epilimnion (DF) 371.0 1400 9800 0.86
Metalimnion (DF) 21.3 900 4200 0.97
Hypolimnion (DF) 17 1 900 4200 0 96Hypolimnion (DF) 17.1 900 4200 0.96
Ultramicro-trophic
Micro-trophic
Oligo-trophic
Meso-trophic Eutrophic Super-
trophicHypereu-trophicp p
* TP > OP
BR – Before restoration, AMR – Aquatic macrophyte removal, DF – During filtration
Comparing techniquesY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
S.No
Aerators Oxygenproduction(kg/KWh)
Operationalcost (Rs)
Location
1.
2.3.
CP 150 (natural aeration)Surface low- speedSurface high speed
0.7
0.70.7
2,210
221+7000*221+7000*
Surface
SurfaceSurface
4.
5.
Submerged turbinewith sparger
Horizontal rotar
0.2
0.5
773.5+7000*
309.4+7000*
Submerged
Submerged
* H ti t
S.No
Aerators Cost perm3
Effect
* - Harvesting cost
1.2.3.4.
CP 150 (natural aeration)Surface low- speedSurface high speedSubmerged turbine with
0.670.060.060.23
Aeration &filtrationAerationAerationAeration
5.
gsparger
Horizontal rotar 0.09 Aeration
Achievements of restorationY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Parameters Initial load (kg)
Load after aquatic macrophyte removal (Kg)
Efficiency%
Load during filtration (Kg)
Efficiency%
removal (Kg)BOD 204 97.9 52 69 66COD 659 326.2 51 225.7 66TKN 153 8 24 4 83 52 5 66TKN 153.8 24.4 83 52.5 66OP 4.3 1.3 70 3.9 9
Efficiency of the restoration process
5060708090
cy %
01020304050
Effic
ien
BOD COD TKN Orthophosphate
Parameters
Aquatic macrophyte removal During filtration& re-aeration
ConclusionY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Conclusion
• From the studies the pond is • Aeration in combination withfilt ti f bi i
pSuper-hypereutrophic (TLI)
• The average saturation level
filtration of biomass is aneffective technique inrestoring an hypereutrophicpond.g
of DO before and after therestoration processes werealmost doubled.
pond.
• Using similar aeration andfiltration technique will help
• Efficiency of bothtechniques in reducing the
f q pin restoring large scalewaterbodies.
techniques in reducing thenutrient concentration andrestoring a pond.
• Simultaneous harvesting ofalgae is effective inrestoring the pond
Future TreatmentY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Future Treatment
• Harvesting of algae by (1) cutting or uprooting Harvesting of algae by (1) cutting or uprooting and removing the weeds from the pond.
• This step requires labour and cost, so further restoration steps should be taken to improve the
lit f th d quality of the pond.
• Probiotic consortium culture synergistically • Probiotic consortium culture synergistically works to inhibit the growth of pathogenic harmful bacterial through competitive exclusion. g p
Dissolved Oxygen(DO) Profiling with depth
DO in mg/L
00 1 2 3 4 5 6
DO in mg/L
0.2
0.4
0.6
0.8
pth
in m
1
1.2
Dep
t
1.2
1.4
1 61.6
Site 'A' Site 'B' Site 'C' Site 'D' Site 'E'
B
A
D
C
A
E
Change in water quality during restoration in epilimnion
23.8
20
25
L
15.415
20
n in
mg/
9.8
4 8
9.810
cent
ratio
3.21.1
4.4
0.15 0.4
4.8
1.4 1.4
0
5conc
0DO NH4-N TKN PO43—P
parameterspbefore restoration after w ater cabbage removal during f iltration
Change in water quality during restoration in epilimnion
371
350
400
250
300
in m
g/L
168
96150
200
entr
atio
n
5280.5
30
96
3914
4550
100
conc
e
0BOD COD chlorophyll a
tparameters
before restoration after w ater cabbage removal during f iltration
Change in water quality during restoration in metalimnion
77
8
L
3 94.2
5
6
n in
mg/
L
3
3.9
2
3
4
cent
ratio
n
0.150.5
0.8 0.9
0
1
2
conc
0DO NH4-N TKN PO43—P
parameters
after w ater cabbage removal during f iltration
Change in water quality during restoration in metalimnion
92
8090
100
L
607080
n in
mg/
L
27
43
21.3304050
cent
ratio
n
13.914
01020
conc
0BOD COD chlorophyll a
parameters
after w ater cabbage removal during f iltration
Change in water quality during restoration in hypolimnion
4.2 4.2
44.5
L
2 53
3.5
n in
mg/
L
1.2
1.9
1.1 0.91.5
22.5
cent
ratio
0.1 0.3
0 9
00.5
1
conc
0DO NH4-N TKN PO43—P
parameters
after w ater cabbage removal during f iltration
Change in water quality during restoration in hypolimnion
86
94
90100
L
607080
n in
mg/
L
2328
304050
entr
atio
n
23
1.1
17.1
0102030
conc
0BOD COD chlorophyll a
parametersp
after water cabbage removal during filtration
Efficiency of the restoration processEfficiency of the restoration process
90
5060708090
cy %
20304050
ficie
nc
01020Ef
f
BOD COD TKN Orthophosphate
Parameters
Aquatic macrophyte removal During filtration& re-aeration
Changes during restorationY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Change in water quality during restoration in epilimnion
Change in water quality during restoration in epilimnionesto at o ep o
23.8
20
25
mg/
L
p
371350400
mg/
L
15.4
9.8 9.810
15
20
ntra
tion
in
168
96
257
13180 5
140150200250300350
atio
n in
m
3.21.1
4.4
0.4
4.8
1.40.15 1.4
0
5
10
conc
e 523096
391445
80.5
050
100150
BOD COD chlorophyll TSSco
ncen
trDO NH4-N TKN PO43—P
parameters
BOD COD chlorophylla
TSS
parametersbefore restoration after w ater cabbage removal during filtrationbefore restoration after w ater cabbage removal during f iltration before restoration after w ater cabbage removal during f iltration
Changes during restorationY. Prathishta, Dirk Walther, K. Thanasekaran (2008)
Change in water quality during restoration in metalimnion
Change in water quality during restoration in metalimnion
7
3 9 4 25678
in m
g/L
92
149
107125150175
on in
3
0 5
3.9
0.8
4.2
0.92345
cent
ratio
n
27
92
14
43
13.9 21.3255075
100
conc
entra
tim
g/L
0.50 80.15
01
DO NH4-N TKN PO43—P
parametersco
n
025
BOD COD chlorophylla
TSS
c
parameters
after water cabbage removal during filtration
parameters
after water cabbage removal during filtration