View
215
Download
0
Category
Preview:
Citation preview
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 1/50
BIODEGRADATION AND CHARACTERIZATION OF
URBAN SOLID WASTE
BY
ABIOYE, SAMSON OLUWAFEMI
1
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 2/50
TABLE OF CONTENT
List of Tables iv
List of Figures v
Abstract vi
CHAPTER ONE
1.1 Background of Study 1
1.2 Aim and Objectives
1.! Sco"e of Study
1. #ustification of Study
1.$ Outline of ot%er &%a"ters
CHAPTER TWO
2.1 T%e 'aste Stream $
2.1.1 (%ysical com"osition of solid urban )astes *
2.1.2 &%emical com"osition of organic )astes *
2.1.! &%emical c%aracteristics of t%e matured solid urban )aste com"ost +2.2 'aste Treatment 1,
2.! -rban 'aste anagement Strategy 1,
2.!.1 'aste com"osting "rocesses 1!
2.!.2 &o/com"osting 1$
2.!.2.1 O"en co/com"osting 1*
2.!.2.2 O"en )indro) com"osting 10
2.!.2.2.1 O"en )indro) com"osting "rocess 10
2.!.2.2.2 ecom"osition "rocess 10
2.!.2.2.! &ontainer design and use 1+
2.!.2.! n/vessel co/com"osting 13
2.!.! 4merging com"osting "rocesses 13
2. (erformance and "roblems of com"osting 22
2.$ Benefits of &om"osting 22
CHAPTER THREE
!.1 aterials 2!
2
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 3/50
!.2 45ui"ments6 7eagents and A""aratus 2!
!.! 48"erimental (rocedure 2
!.!.1 'aste "re"aration 2
!.!.2 &%aracterisation of )astes used for com"osting 2
!.!.2.1 ry as%ing sam"le "re"aration 2
!.!.2.2 etermination of carbon content 2*
!.!.!.! etermination of nitrogen content 2*
!.!.! &om"osting "rocess 20
!.!. (rocess monitoring and sam"ling 2+
CHAPTER FOUR
.1 7esults 23
.2 iscussion of 7esults !*
CHAPTER FIVE
$.1 &onclusion !+
$.2 7ecommendations !+
7eferences ,
3
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 4/50
List of Tab!s
Tab!s Tit! Pa"!s
2.1 &%emical com"osition of ra) materials used for com"osting 0
2.2 &%emical "ro"erties of t%e matured solid urban )aste com"ost 3
2.! erits and demerits of co/com"osting 21
!.1 &om"osition of t%e t)o )aste mi8tures for t%e com"osting "rocess 2+
.1 &%emical com"osition of )aste materials used for com"osting !,
.2 9utrient values of com"osite )aste before com"osting !,
.! Bio/degradation of mi8ture &1 !1
. Bio/degradation of mi8ture &2 !1
.$ 9utrient values of t%e matured solid urban )aste com"ost !1
4
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 5/50
List of Fi"#$!s
Fi"#$! Tit! Pa"!
.1 &arbon to nitrogen content com"arison of )aste materials used !2
.2 9utrient values of com"osite )aste before com"osting !2
.! Tem"erature:time correlation of sam"le &1 during com"osting "rocess !!
. Tem"erature/time correlation of sam"le &2 during com"osting "rocess !!
.$ ";:time correlation of sam"le &1 during com"osting "rocess !
.* ";:time correlation of sam"le &2 during com"osting "rocess !
.0 9utrient values of t%e matured solid urban )aste com"ost. !$
5
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 6/50
ABSTRACT
7a"id urbani<ation and "o"ulation gro)t% are largely res"onsible for very %ig%
increasing rate of solid )aste in t%e urban areas6 its "ro"er management and recycling is
major "roblems of unici"al &or"oration. T%e study attem"ts to manage "ro"er6
"%ysicoc%emical analysis of -rban Solid 'aste =-S'> and its conversion to enric%ed
com"ost by ecofriendly "rocess.
For t%is study6 turned )indro)s met%od for com"osting of -rban Solid 'aste )as
used follo)ing t%e c%aracteri<ation of t%e various )aste materials and t%e com"osite )aste
material. microbial inoculums )ere added uniformly and tem"erature6 "; and moisture
content )ere maintained t%roug%out t%e com"osting "rocess. T%e c%emical com"osition of
com"ost obtained at t%e end of t%e com"osting "rocess s%o)ed t%e de"endence of o"timal
com"osting "rocess on t%e a""ro"riate &?9 ratio in t%e )aste materials.
T%e initial com"ositions of urban )aste indicated an organic carbon status of 2!.1@
)it% t%e &? 9 ratio of 32. T%e additives used in solid urban )aste com"osting suc% as co)
dung and green manure recorded organic carbon content of 1,.$, and 13.,* and &?9 ratio of
2$.*1 and 3.,!. T%e study s%o)ed t%at t%e %ig%er t%e &?9 ratio t%e lo)er t%e 5uality of t%e
resulting com"ost. T%e &1 com"osite )aste )it% t%e &?9 ratio of 3$.* resulted in a lo)
9itrogen value of t%e final com"ost6 com"ared to t%at of &2 )it% lo)er &?9 ratio as s%o)n inTables .2 and .$. T%e com"osting "rocesses of t%e t)o com"osite sam"les )ere furt%er
com"are using t%e "; and tem"erature "rofiles as s%o)n in Figures .! / .*
T%e results of t%e study clearly indicated t%at t%e recycling of solid urban )aste can
transform garbage or munici"al solid )aste to enric%ed com"osts. T%is is a "ractical
significance if ado"ted by urban farmers as a result of soil %ealt% and in turn t%e "roductivity
of soil can be maintained for furt%er agriculture.
6
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 7/50
CHAPTER ONE
INTRODUCTION
T%e elimination of a )ide range of "ollutants and )astes from t%e environment is an
absolute re5uirement to "romote a sustainable develo"ment of our society )it% lo)
environmental im"act. Biological "rocesses "lay a major role in t%e removal of contaminants
and t%ey take advantage of t%e astonis%ing catabolic versatility of microorganisms to degrade
and convert suc% com"ounds. Biodegradation is t%e term used to describe t%e natural decay
of )astes as a result of t%e action of bacteria. Biodegradation is also defined as t%e c%emical
breakdo)n of materials by a "%ysiological environment. T%e term is often used in relation to
ecology6 )aste management and environmental remediation = bioremediation>. Organic
material can be degraded aerobically )it% o8ygen6 or anaerobically6 )it%out o8ygen.
Biodegradable matter is generally organic material suc% as "lant and animal matter and ot%er
substances originating from living organisms6 or artificial materials t%at are similar enoug% to
"lant and animal matter to be "ut to use by microorganisms. Biodegradation involves t%e
"rocess in )%ic% a "roduct is ca"able of being broken do)n into innocuous sub/"roducts6
like &arbon =iv> o8ide and )ater6 by t%e action of living t%ings =microorganisms>. Banana
"eels )ill biodegrade into biomass6 &arbon =iv> o8ide and )ater. (roducts t%at are susce"tible
to biodegradation are also referred to as bioactive='iki"edia6 2,,3>.
7ecycling involves t%e collection6 "rocessing6 and reuse of materials t%at )ould
ot%er)ise be t%ro)n a)ay. aterials usually solid )astes ranging from "recious metals to
broken glass6 from old ne)s"a"ers to "lastic s"oons6 can be recycled. T%e recycling is also
e8tended to kitc%en )astes6 )eeds and farm yard manure. T%e recycling "rocess reclaims t%e
original material and uses it in ne) "roducts. 7ecycling decreases t%e amount of land needed
for tras% dum"s by reducing t%e volume of discarded )aste t%ereby reducing "ollution
%;eimlic% et al 6 2,,1>.
-rban Solid 'aste is defined as t%e organic and inorganic )aste materials "roduced
from different sources and %ave lost value in t%e eye of t%eir o)ner =As%a et al 6 2,,+>.
&ointreau =2,,*> defined unici"al solid )aste as garbage t%at comes from %omes6
businesses6 and sc%ools. unici"al solid )aste does not include construction )aste6
industrial )aste6 or se)age )aste. unici"al solid )aste can be classified in t)o )ays?
By aterial6 t%at is )%at t%e )aste is made of. 'aste may be "lastic6 "a"er6 metal6
rubber6 food )aste6 or yard )aste. A "lastic toy and a "lastic yogurt carton )ould be
7
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 8/50
in t%e same materials category because t%ey are bot% made of "lastic.
By (roduct6 t%at is )%at t%e )aste )as used for originally. T%e )aste may be an old
"otato c%i" bag6 a )orn/out s%oe6 or a broken toy. A "lastic beverage container and an
aluminum beverage container )ould be in t%e same "roduct category because t%ey are
bot% used as containers.
&'& Ba()"$o#*+ of St#+
Solid )aste dis"osal "oses a greater "roblem because it leads to land "ollution if
o"enly dum"ed6 )ater "ollution if dum"ed in lo) lands6 and air "ollution if burnt. 9igeria
and majority of t%e develo"ing countries are facing serious environmental degradation and
"ublic/%ealt% risk due to uncollected dis"osal of )aste on streets and ot%er "ublic areas6
drainage congestion by indiscriminately dum"ed )astes6 and contamination of )ater resources near uncontrolled dum"ing sites =Faisal6 2,,$>.
According to Samant%a =2,,0>6 )%en solid )astes are "oorly managed6 t%ey can
cause considerable t%reats to t%e environment and %uman %ealt% as it decom"oses6 during
incineration6 and t%roug% t%e leac%ing of to8ins. T%e incineration of )aste emits c%emicals
detrimental to %uman %ealt%6 most notably dio8ins6 furans6 and mercury. T%is "oses a t%reat
to %uman %ealt%. An additional concern is t%e large accumulation of met%ane during )aste
decom"osition. According to t%e &%ina &ouncil for nternational &oo"eration on4nvironment =&&&46 2,,0> re"ort6 alarming rate of met%ane e8"losions in )aste "iles and
landfills %as been re"orted over t%e "ast fe) years.
One of t%e major environmental concerns in urban areas today is t%e issue of Solid
'aste anagement. T%e collection6 trans"ortation and dis"osal of solid )aste are normally
done in an unscientific and c%aotic manner. -ncontrolled dum"ing of )astes on outskirts of
to)ns and cities %as created overflo)ing landfills6 )%ic% are not only im"ossible to reclaim
because of t%e %a"%a<ard manner of dum"ing6 but also %ave serious environmental
im"lications in terms of ground )ater "ollution and contribution to global )arming. An
effective system of solid )aste management is t%e need of t%e %our and s%ould be
environmentally and economically sustainable. &om"osting is t%e sim"lest yet best "rocess
for solid )aste management for our condition. t is basically a s"ecial form of 'aste
Stabili<ation t%at re5uires s"ecial conditions of moisture and aeration to "roduce stable
com"ost )%ic% can be used as a lo) grade manure and soil conditioner =eenambal et al 6
2,,!>.
T%e 7e"lenis%ing of t%e soil %ealt% by "roviding t%e muc% needed organic matter6 lest
8
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 9/50
t%e soil become im"overis%ed %as been a major concern. T%e sco"e and "otential for
recycling variety of resources in agriculture is vat by any standards. 'astes recycling can
bring tremendous benefits to agriculture and land management in long run. n addition t%ere
are t%e benefits of a cleaner environment6 a %ealt%ier %abitat and an intelligent use of all
available recyclable resources )it%out condemning t%em as )astes. To)ards t%is end urban
solid )aste com"ost could serve as a valuable organic matter source given t%e s%ortage of
organic nutrient source. efining 5uality standards for organic manures is a very difficult
task given t%e %eterogeneity of residues t%at occur in city )astes and "rocessing met%ods
ado"ted. ntegrated nutrient management combining bot% inorganic and organics resulting in
)%olesome im"rovement of t%e soil. Faced )it% suc% situation utili<ing valuable urban
resources for manure "roduction )ould be viable alternative given t%e ever increasing urban
status resulting in urban )aste "roduction. T%is can be done by ado"ting t%e tec%nology of
com"ostingC. T%e term com"osting refers to a biological "rocess in )%ic% organic urban
solid )aste material is broken do)n by t%e action of micro/organisms. T%e degradation
"rocess takes "lace in t%e "resence of air =aerobic> and results in elevated "rocess
tem"erature and t%e "roduction of &arbon =iv> o8ide6 )ater and stabili<ed organic residue.
T%e key feature of t%e com"osting "rocess is t%e generation of %eat by biological activity
during t%e decom"osition of t%e substrate materials. By forming t%e )aste into large masses
under a""ro"riate conditions6 t%ey )ill reac% %ig% tem"erature6 resulting in ra"id
degradation. ore im"ortantly6 t%ese tem"erature %ave a saniti<ing effect u"on t%e )aste6
reducing t%e numerous of "at%ogenic organism =Dautam et al 2,,3>.
(ractices for collecting6 "rocessing6 and dis"osing of munici"al solid )aste vary
)idely across countries6 generally in accord )it% t%e nature of t%e )aste stream and key
environmental and economic features. T%e least efficient "ractices tend to be found in
develo"ing countries6 creating serious t%reats to local environmental 5uality and "ublic
%ealt%. Suggestions %as been made t%at im"rovements made no) in t%e %andling of
%a<ardous )aste )ill be far less e8"ensive in discounted terms t%an undoing in t%e future t%e
damage being caused by current "ractices. Addressing t%ese issues from a rational societal
"ers"ective )ill become increasingly urgent in t%e future6 es"ecially in t%e develo"ing
countries6 )%ere "rojections %as been made t%at munici"al solid )aste )ill increase at an
annual rate of 2.0 "ercent t%roug% t%e year 2,1, =avid and avid6 2,1,>.
&'- Ai. a*+ Ob/!(ti0!s
T%e aim of t%e "roject )ork is to biodegrade unici"al Solid 'astes.
9
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 10/50
T%e objectives of t%e study areE
c%aracteri<ation of unici"al-rban Solid 'astes
making com"ost from t%e c%aracteri<ed )astes and
c%aracteri<ation of t%e resulting com"ost.
&'1 S(o2! of St#+
T%e study =)aste collection6 com"ost "re"aration and sam"le analyses> is limited
only to solid )astes in Ogbomoso metro"olis.
&'3 4#stifi(atio* of St#+
7a"id urbani<ation and "o"ulation gro)t% are largely res"onsible for very %ig%
increasing rate of solid )aste in t%e urban areas6 its "ro"er management and recycling is
major "roblems of unici"al &or"oration. T%e "ro"osed study attem"ts to manage "ro"erly6
"%ysicoc%emical analysis of -rban Solid 'aste and its conversion to enric%ed com"ost by
ecofriendly "rocess.
&'5 O#ti*! of ot6!$ C6a2t!$s
T%e Literature revie) of t%e "roject )ork revie)s a number of )aste management
strategies. T%e )aste treatment strategies revie)ed areE o"en )indro) com"osting6 in/vesselcom"osting as )ell as vermiculture "rocesses.
T%e t%ird c%a"ter caters for t%e major com"osting activities )%ic% includes collection
of solid )aste6 se"aration of reusable com"onents =recycling> and bioconversion of
biodegradable com"onents into organic fertiliser as )ell as t%e o"timum com"osting
conditions and t%e c%aracteri<ation "rocedures for "ro"er degradation "rocess alongside t%e
"rocess monitoring and t%e sam"ling "rocesses to be ado"ted.
T%e re"ort s%o)s e8tensively t%at t%e biodegradation "rocess largely de"ends on t%e
)aste c%aracteristics. Also6 t%e "; and tem"erature "rofiles during t%e com"osting "rocess
)ere )ell analysed.
T%e last c%a"ter indicated t%at t%e biodegradation of solid urban )astes can transform
garbage to enric%ed com"osts and a number of recommendations for future studies )ere
made
CHAPTER TWO
LITERATURE REVIEW
T%e standards and norms for %andling munici"al solid )astes in industriali<ed
10
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 11/50
countries %ave reduced occu"ational %ealt% and environmental im"acts substantially. About
t%ree decades ago6 %ig%/income countries re5uired o"en dum"s to be covered daily )it% soil
to curtail vector access6 and t%us be u"graded to controlled landfills. Since t%e early 130,Gs6
)%en it became a""arent t%at even controlled landfills may cause significant )ater "ollution6
sanitary landfill tec%nology )as develo"ed to "rovide barriers to "ollutant migration6 as )ell
as to "rovide leac%ate and gas collection and treatment systems.
ost common "ractices of )aste "rocessing are uncontrolled dum"ing )%ic% causes
mainly )ater and soil "ollution. Besides dum"ing or sanitary land filling6 t%e final dis"osal of
solid )aste can be carried out by ot%er met%ods like incineration and com"osting =rec%sel
and Hun<e6 2,,1>.
-'& T6! Wast! St$!a.
Solid )aste comes from various sources. According to 4ncyclo"edia of (ublic ;ealt%
unici"al Solid 'aste =2,1,>6 t%e estimated "ercentages for unici"al Solid 'aste areE
7esidential6 institutional6 commercial6 and industrial? $$ to *, "ercent by )eig%t
&onstruction and demolition )aste? 1$ to 2, "ercent
Se)age sludge? 1 to 2 "ercent
edical )aste =including "otentially infectious material>? 1 to 2 "ercent and
;arbour debris? less t%an 1 "ercent.
redge s"oil can make u" to 1$ to 2, "ercent of t%e )aste in a coastal city )it% a
%arbour. Ot%er forms of )aste t%at can vary by location include agricultural )aste6
mining )aste6 and %a<ardous )aste.
'aste streams differ also in t%e follo)ing attributes?
(%ysical "ro"erties =e.g. com"actibility6 density>
&ombustion "ro"erties =tem"erature6 residual as% "ercentage6 %eat content in BT-s>
c%emical com"ositionE "ercentage of nitrogen6 carbon6 o8ygen6 c%lorine
concentrations of to8ic "olyaromatic %ydrocarbons =(A;s> and metals
"otential for recycling various com"onents and
ease of se"aration.
-'&'& P6si(a (o.2ositio* of soi+ #$ba* 7ast!s
11
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 12/50
unici"al solid )aste com"osition )as observed very demogra"%ically. (rior to
segregation6 t%e solid urban )astes consisted of some reusable material suc% as "lastic6
metals6 glass and "a"er )%ic% totally constituted to about $!@. T%is )as se"arated and
furt%er used in recycling industries. Iegetable matter and ot%er decom"osable is t%e
"redominant constituent )%ic% are "resent to an e8tent of 0@ =Dautam et al, 2009 >.
-'&'- C6!.i(a (o.2ositio* of o$"a*i( 7ast!s
According to Dautam et al =2,,3>6 t%e c%emical com"ositions of various organic
materials used for "re"aring t%e com"ost are given in Table 2.1. -rban )aste is one of t%e
"otential nutrient organic residues6 )%ic% on recycling yield valuable and nutrient ric%
"roduct kno)n as com"ost. T%e urban )aste is found to be slig%tly alkaline in nature =";
0.0*> and )as fairly lo) in 9itrogen6 9 =,.,@>6 (%o"%orous6 ( =,.,,,1+@>6 fairly ric% in
(otassium6 H =,.!$@> and Sodium6 9a =!.@>. T%e organic carbon )as !+@ )it% a &? 9
ratio of 3$,?,.,. Dreen leaves )ere ric% in 9 =,.0$@> and )as used to su""lement 9itrogen
to initially counter t%e nitrogen de"letion. &o) dung used as an additive or inoculum for t%e
com"ost treatments. T%is mainly served as a starter material for com"osting. t also en%ances
t%e decom"osition of cellulosic "lant material and it %ad ,.+$@ 9 )it% a &?9 ratio of !,.11.
Tab! -'&8 C6!.i(a (o.2ositio* of $a7 .at!$ias #s!+ fo$ (o.2osti*"
&%aracteristics -rban )aste &o) dung Dreen leaves
"; 0.0*,, 0.1, 0.!2
12
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 13/50
4& =Js cm/1> 1$.,,,, 1!*!.,, 123*.,,
Organic carbon =@> !+.,,,, 2$.*, !.*,
9itrogen =@> ,.,,, ,.+$ !.,+
(%os"%orus =@> ,.,,1+ ,.20 ,.1
(otassium =@> ,.!$,, ,.!* 1.*$
Sodium =@> !.,,, 2.2* 1.*!
&? 9 ratio 3$,.,,,, !,.11 11.2!
&r =mg kg/1> 22.,,, 12.$, 1+.!,
&d =mg kg/1> ,.2,,, ,., ,.,1
&u =mg kg/1> *$.!*,, 2.$, $.!,
Fe =mg kg/1> 1,*,.,,,, 122$.,, 12$!.,,
Kn =mg kg/1> 0,.,,, +.2, $2.0,
n =mg kg/1> !$*.,,,, 2.,, 20.,,
9i =mg kg/1> !.*,,, 2.!, 22.*,
(b =mg kg/1> 22.2,,, 2.$2 1.$2
So#$(!8 %Ga#ta. et al -99:;
-'&'1 C6!.i(a (6a$a(t!$isti(s of t6! .at#$!+ soi+ #$ba* 7ast! (o.2ost
T%e data on c%emical "ro"erties of t%e matured solid urban )aste com"osts are given
in Table 2.2 =Dautam et al 2,,3>. T%e "; of all t%e com"osts )ere neutral to slig%tly
alkaline. T%is )as described to be due to t%e natural buffering of t%e %umus. ;ig%est "; )as
recorded in &! com"ared to ot%ers. According to Dautam et al =2,,3>6 t%e result concurred
)it% t%e observation of ';O t%at t%e munici"al com"ost )as slig%tly alkaline in nature and
13
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 14/50
%ad a marked buffering ca"acity. T%e "ercent organic carbon varied bet)een %is treatments.
T%e %ig%er t%e 9itrogen content in t%e ra) material used6 t%e %ig%er t%e 9itrogen content in
t%e final com"ost =Dautam et al 2,,3>.
T%e enric%ment of urban )aste )it% rock "%os"%ate yielded com"osts )it% %ig%
(%os"%orous content. T%e enric%ment of com"ost )it% additives increased t%e decom"osition
rate6 )%ic% may be due to availability of essential nutrients for t%e increased biological
activity. According to i et al =2,,3>6 enric%ment of com"ost )it% nutrients like
(%os"%orous in t%e form of rock "%os"%ate resulted in %ig% value com"ost due to %ig%er
degree of decom"osition.
Tab! -'-8 C6!.i(a 2$o2!$ti!s of t6! .at#$!+ soi+ #$ba* 7ast! (o.2ost
&%aracteristics &1 &2 &! & &$ &*
14
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 15/50
"; 0.,2 0.$! 0.$* 0.10 0.1, 0.$
4& =Js cm/1> 1!3.,, 1!*!.,, 11$1.,, 1$.,, 12$.,, 1!3.,,
Organic carbon =@> !+.,, 2+.,, !2.,, !0.,, !!.,, !3.,,
9itrogen =@> ,., ,.,* ,.,* ,.,$ ,.,$ ,.,0
(%os"%orus =@> ,.,,1+ ,.,,2, ,.,,,* ,.,,1* ,.,,22 ,.,,$
(otassium =@> ,.!$ ,.$ ,.!, ,., ,., ,.$
Sodium =@> !., .3, !.+, $.0, $., .!,
&?9 ratio 3$,.,, **.** $!!.!! 0,.,, **,.,, $$0.1
&r =mg kg/1> 22., !!.*, !,., 2+.2, 23.,, 21.,
&d =mg kg/1> ,.2, BL ,.2, BL ,., ,.+,
&u =mg kg/1> *$.!* 1,1.++ 30.1* $.!2 !.0, *.1*
Fe =mg kg/1> 1,*, 1*1+, 131+, 1302, 1+*, 1*,
Kn =mg kg/1> 0,., 3$.,, !.,, *1.*, 0+., *!.,
n =mg kg/1> 2.,, !$*.,, 2+,.,, 20.,, 2$*.,, 2*0.,,
9i =mg kg/1> !.*, $*., 1.,, $0.*, 0.*, 2.*,
(b =mg kg/1> 22.2, 2*.+, 13., 1,.2, 1.+, 12.*,
So#$(!8 %Ga#ta. et al -99:;
-'- Wast! T$!at.!*t
T%ere are more t%an t%irty tec%nological a""roac%es to managing solid )aste. One of
t%e most common is incineration6 )%ic% re5uires a burner and often a su""lemental source of
fuel. T%e tem"erature and t%e residence time of t%e )aste in t%e burner determine t%e
efficiency )it% )%ic% organic matter is converted to carbon. 9on/combustible material6
15
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 16/50
"articularly metals6 accumulate in t%e as% and must be removed eit%er to landfills or for
incor"oration into concrete and ot%er construction "roducts. As organic matter cools in t%e
stack6 un)anted "roducts suc% as dio8ins may also form. &om"osting allo)s organic material
to undergo biodegradation and "%oto degradation6 resulting in sim"le organic molecules t%at
can actually be beneficial to t%e environment =rec%sel and Hun<e 2,,1>.
4art%)orm farming =vermiculture> is anot%er bio/tec%ni5ue for converting t%e solid
organic )aste into com"ost =D%os%6 2,,>. An innovative disci"line of vermiculture
biotec%nology6 t%e breeding and "ro"agation of eart%)orms and t%e use of its castings %as
become an im"ortant tool of )aste recycling all over t%e )orld. 4ssentially6 t%e vermiculture
"rovides for t%e use of eart%)orms as natural bioreactors for cost/effective and
environmentally sound )aste management. 9o) t%ere is an all/round recognition t%at
ado"tion and e8"loitation of vermiculture biotec%nology besides arresting ecological
degradation could go a long )ay to)ards meeting t%e nutrient needs of t%e agricultural sector
in a big )ay=As%a6 2,,+>.
-'1 U$ba* Wast! Ma*a"!.!*t St$at!"
any a""roac%es to )aste management e8ist. Denerally6 solid )aste is managed
t%roug% landfills6 incineration and recycling or reuse. ;o)ever in develo"ing countries6
"ro"erly engineered landfills are not common )%ile t%e cost of modern incineration is too
e8orbitant to bear. ;ence6 t%e most common met%od of )aste dis"osal is some form of
landfill6 including variants suc% as uncontrolled dum"ing in undefined areas6 collection and
dis"osal on unmanaged o"en dum"s6 collectiondis"osal on controlled dum"sites =-94(6
2,,>. t is common to find scavengers moving from door to door or sorting t%roug%
communal bins to "ick dry recyclable materials. ;o)ever6 t%ese "ickers are more interested
in inorganic recyclable materials suc% as "lastics and glass6 but not in organic )astes.
T%e general "rinci"le of t%e )aste management %ierarc%y consists of t%e follo)ing ste"s?
inimising )astes
a8imising environmentally sound )aste reuse and recycling
16
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 17/50
(romoting environmentally sound )aste dis"osal and treatment
48tending )aste service coverage
&urrent urban organic )aste recycling "ractices include t%e follo)ing
T%e use of fres% )aste from vegetable markets6 restaurants and %otels6 as )ell as food
"rocessing industries as feed for urban livestock =Allison et al. 133+>
irect a""lication of solid )aste on and into t%e soil
ining of old )aste dum"s for a""lication as fertili<er on farmland =Lardinois and
van de Hlundert6 133!>
A""lication of animal manure suc% as "oultry"ig manure and co) dung
irect a""lication or %uman e8creta or bio/solids to t%e soil =&ofie et al.6 2,,$>
Organised com"osting of solid )astes or co/com"osting of solid )astes )it% animal
manure or %uman e8creta.
'%ic%ever met%od is used6 a "rocess of microbial degradation releases t%e useful
nutrients in organic )aste for soil im"rovement and "lant gro)t%.
Kurbrugg and resc%er =2,,2> re"ort t%at t%e "otential benefits of organic )aste recycling
are "articularly in reducing t%e environmental im"act of dis"osal sites6 in e8tending e8isting
landfill ca"acity6 in re"lenis%ing t%e soil %umus layer and in minimising )aste 5uantity. Ot%er
benefits ada"ted and summarised from ;oorn)eg et al . =1333> )it% "articular reference to
organic )aste com"osting are t%at it?
increases overall )aste diversion from final dis"osal6 es"ecially since as muc% as +,
"ercent of t%e )aste stream in lo)/ and middle/income countries can be com"osted
en%ances recycling and incineration o"erations by removing organic matter from t%e
)aste stream
"roduces a valuable soil amendment integral to sustainable agriculture
17
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 18/50
"romotes environmentally/sound "ractices6 suc% as t%e reduction of met%ane
generation at landfills
en%ances t%e effectiveness of fertili<er a""lication
can reduce )aste trans"ortation re5uirements
is fle8ible for im"lementation at different levels6 from %ouse%old efforts to large/scale
centralised facilities
can be started )it% very little ca"ital and o"erating costs
t%e climate of many develo"ing countries is o"timum for com"osting
addresses significant %ealt% im"acts resulting from organic )aste suc% as reducing
engue Fever
"rovides an e8cellent o""ortunity to im"rove a cityGs overall )aste collection
"rogramme
accommodates seasonal )aste fluctuations suc% as leaf litter and cro" residues
can integrate e8isting informal sectors involved in t%e collection6 se"aration and
recycling of )astes.
&om"osting %as been an attractive o"tion in many res"ects. t is t%e "rocess of
decom"osing or breaking do)n organic )aste materials =by micro/organisms suc% as
bacteria6 "roto<oans6 fungi6 invertebrates> into a valuable resource called com"ost.
&om"osting is done at different scales =large6 medium6 small> by various "eo"le
=munici"alities6 9DOs6 communities6 individuals> and for various "ur"oses =gardening6landsca"ing6 farming> in t%e urban areas =Onibokun6 1333>.
According to ;oorn)eg et al =1333>6 t%e com"osting "rocess is also constrained by t%e
follo)ing factors?
nade5uate attention to t%e biological "rocess re5uirements
18
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 19/50
Over/em"%asis "laced on mec%anised "rocesses rat%er t%an labour/intensive
o"erations
Lack of vision and marketing "lans for t%e final "roduct / com"ost
(oor feed stock )%ic% yields "oor 5uality finis%ed com"ost6 for e8am"le )%en
contaminated by %eavy metals
(oor accounting "ractices )%ic% neglect t%at t%e economics of com"osting rely on
e8ternalities6 suc% as reduced soil erosion6 )ater contamination6 climate c%ange6 and
avoided dis"osal costs
-'1'& Wast! (o.2osti*" 2$o(!ss!s
T%e "rocess of )aste com"osting includes t%e determination of t%e ty"e of facility6
o"timal number6 ca"acity6 and location of com"ost stations "er city. ost critical in t%is
assessment is to include "ossible )ays of com"osting )it% due consideration of )aste su""ly
and com"ost demand. &om"osting is best ac%ieved by "roviding o"timal conditions for t%e
micro/organisms t%roug% t%e best combination of air6 moisture6 tem"erature and organic
materials =Agromisa6 1333>. &om"osting "rocesses can be aerobic =)it% o8ygen> or
anaerobic =)it%out o8ygen> and even alternate bet)een t%e t)o during t%e decom"osition
"rocess. Anaerobic com"osting is a lo)/tem"erature "rocess t%at is not recommended for
urban agriculture due to t%e strong odours and t%e inability to destroy %armful "at%ogens t%at
may be "resent in urban organic )aste. &onversely6 aerobic com"osting is a %ig%/tem"erature
"rocess due to t%e develo"ment of microbes t%at generate %ig%er tem"eratures in t%e com"ost
"ile. T%e key factors affecting t%e biological decom"osition "rocesses andor t%e resulting
com"ost 5uality are?
&arbon to nitrogen ratio
oisture content
O8ygen su""ly6 aeration
(article si<e
";
Tem"erature
19
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 20/50
Turning fre5uency
icro/organisms and invertebrates
&ontrol of "at%ogens
egree of decom"osition
9itrogen conservation
T%e c%oice of a tec%nology for aerobic com"osting )ill de"end on t%e location of t%e
facility6 t%e ca"ital available and t%e amount and ty"e of )aste delivered to t%e site. T%e t)o
main ty"es of systems generally distinguis%ed are?
o"en systems suc% as )indro)s and static "iles and
closed in/vessel systems. T%ese in/vessel or reactor systems can be static or
movable closed structures )%ere aeration and moisture is controlled by mec%anical
means and often re5uires an e8ternal energy su""ly. Suc% systems are usually
investment intensive and also more e8"ensive to o"erate and maintain. O"en
systems are t%e ones most fre5uently used in develo"ing countries. T%ey are classified
according to Akvo"edia =2,1,> as?
Bi* (o.2osti*"? &om"ared to )indro) systems6 bin systems are contained by a constructed
structure on t%ree or all four sides of t%e "ile. T%e advantage %ere is a more efficient use of
s"ace.
T$!*(6 a*+ 2it (o.2osti*"? Trenc% and "it systems are c%aracterised by %ea"s )%ic% are
"artly or fully contained under t%e soil surface. Structuring t%e %ea" )it% bulky material or
turning is usually t%e c%oice for best aeration. &ontrol of leac%ing is difficult in trenc% or "itcom"osting. n some cases6 com"osting materials are com"letely buried in t%e trenc% )%ic%
t%en serves as a "lanting bed. T%e aerobic com"osting "rocess can last from a fe) )eeks to
!/ mont%s6 de"ending on t%e ty"e of com"osting feedstock and t%e met%od of com"osting.
Wi*+$o7, 6!a2 o$ 2i! (o.2osti*"? T%e material is "iled u" in %ea"s or elongated %ea"s
=called )indro)s>.
-'1'- Co<(o.2osti*"
20
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 21/50
&o/&om"osting is t%e controlled aerobic degradation of organics using more t%an one
materials =Faecal sludge and Organic solid )aste>. Faecal sludge %as a %ig% moisture and
nitrogen content )%ile biodegradable solid )aste is %ig% in organic carbon and %as good
bulking "ro"erties =i.e. it allo)s air to flo) and circulate>. By combining t%e t)o6 t%e benefits
of eac% can be used to o"timi<e t%e "rocess and t%e "roduct. For de)atered sludges6 a ratio of
1?2 to 1?! of de)atered sludge to solid )aste s%ould be used. Li5uid sludges s%ould be used
at a ratio of 1?$ to 1?1, of li5uid sludge to solid )aste =Akvo"edia6 2,1,> .
&om"osting can be done eit%er in "its or concrete tanks or )ell rings or in )ooden or
"lastic crates a""ro"riate in a given situation. t is "referable to select a com"osting site under
s%ade6 in t%e u"land or an elevated level6 to "revent )ater stagnation in "its during rains =Ali6
2,,>.
A &o/&om"osting facility is only a""ro"riate )%en t%ere is an available source of )ell/
sorted biodegradable solid )aste. i8ed solid )aste )it% "lastics and garbage must first be
sorted. '%en done carefully6 &o/&om"osting can "roduce a clean6 "leasant6 beneficial
"roduct t%at is safe to touc% and )ork )it%. t is a good )ay to reduce t%e "at%ogen load in
sludge =Bradford 2,,$>.
e"ending on t%e climate =rainfall6 tem"erature and )ind> t%e &o/&om"osting facility
can be built to accommodate t%e conditions. Since moisture "lays an im"ortant role in t%e
com"osting "rocess6 covered facilities are es"ecially recommended )%ere t%ere is %eavy
rainfall. T%e facility s%ould be located close to t%e sources of organic )aste and faecal sludge
=to minimi<e trans"ort> but to minimi<e nuisances6 it s%ould not be too close to %omes and
businesses. A )ell/trained staff is necessary for t%e o"eration and maintenance of t%e
facility=&ofi et al 6 2,,$>.
Adding e8creta6 es"ecially urine6 to %ouse%old organics "roduces com"ost )it% a %ig%er
nutrient value =9/(/H> t%an com"ost "roduced only from kitc%en and garden )astes. &o/
com"osting integrates e8creta and solid )aste management6 o"timi<ing efficiency.
&om"ost can be a""lied in a range of end uses6 )it%in gardens6 on Bro)nfield sites6
landsca"ing and full scale agriculture. T%e screening grades t%e "roducts to bet)een !,mm
and ,mm "articles )%ic%6 de"endent on grade6 can t%en be used as soil im"rover6 mulc%6
to"soil constituent6 turf dressing6 and gro)ing medium.
T%e t)o ty"es of &o/&om"osting designs according to Akvo"edia =2,1,> are?
21
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 22/50
o"en designs and
in/vessel designs.
-'1'-'& O2!* (o<(o.2osti*"
n o"en com"osting6 t%e mi8ed material =sludge and solid )aste> is "iled into long %ea"s
called )indro)s and left to decom"ose. 'indro) "iles are turned "eriodically to "rovide
o8ygen and ensure t%at all "arts of t%e "ile are subjected to t%e same %eat treatment. 'indro)
"iles s%ould be at least 1m %ig%6 and s%ould be insulated )it% com"ost or soil to "romote an
even distribution of %eat inside t%e "ile. e"ending on t%e climate and available s"ace6 t%e
facility may be covered to "revent e8cess eva"oration and "rotection from rain.
To ade5uately treat e8creta toget%er )it% ot%er organic materials in )indro)s6 t%e ';O
=13+3> recommends active )indro) co/com"osting )it% ot%er organic materials for one
mont% at $$/*,M&6 follo)ed by t)o to four mont%s curing to stabilise t%e com"ost. T%is
ac%ieves an acce"table level of "at%ogen kill for targeted %ealt% values.
'indro) &om"osting cannot be used to "rocess organic materials )%ic% include catering
and animal )astes as t%ese %ave to be "rocessed via n/vessel &om"osting or Anaerobic
igestion due to t%eir Animal By/(roducts 7egulations categorisation.
T%e "rocess of )indro) com"osting is relatively sim"le. T%e feedstocks are s%redded6
mi8ed and "laced into )indro)s along a non "ermeable surface. T%e )indro)s are turned on
a regular basis to im"rove o8ygen content6 distribute %eat to regulate tem"erature and to
distribute moisture. T%e )indro)s are turned multi"le times during t%e com"osting "rocess6
)%ic% takes on average si8teen )eeks6 de"ending on maturity re5uirements. T%e last "art of
t%e "rocess involves screening t%e com"ost to remove contaminants suc% as "lastics and
metals6 and to also grade t%e com"ost for various end uses. Oversi<ed materials are also
removed and can be "ut back t%roug% t%e )%ole "rocess until t%ey %ave com"osted do)n
sufficiently.
-'1'-'- O2!* 7i*+$o7 (o.2osti*"
22
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 23/50
'indro) com"osting is used for "rocessing garden )aste6 suc% as grass cuttings6 "runing
and leaves in eit%er an o"en air environment or )it%in large covered areas )%ere t%e material
can break do)n in t%e "resence of o8ygen.
According to Scottis% 4nvironmental (rotection Agency =S4(A> =2,1,>6 o"en )indro)
com"osting is a managed biological "rocess in )%ic% biodegradable )aste is broken do)n by
naturally occurring micro/organisms to "roduce a stabilised residue. O"en )indro)
com"osting can be combined )it% a range of ot%er )aste treatment tec%nologies.
Only meat e8cluded food )astes can be treated6 as sti"ulated by t%e Animal By/ (roducts
=Scotland> =SS 2,,!11> 7egulations. deally t%is "rocess s%ould treat only segregated
biodegradable )aste. i8ed )aste can be treated by anaerobic digestionE %o)ever t%is may
result in contamination of t%e li5uid and solid fractions )%ic% can make t%em less suitable as
soil conditioners or fertili<ers.
-'1'-'-'& O2!* 7i*+$o7 (o.2osti*" 2$o(!ss
'aste is collected and broug%t to t%e site )%ere it is c%ecked to ensure it is of sufficient
5uality. t is t%en s%redded and "iled into )indro)s6 )%ic% are elongated "iles s%a"ed for
ideal com"osting. Aeration is encouraged by suitable mi8ing of t%e initial material and
regular mec%anical agitation =turning>. ecom"osition is allo)ed to continue until t%e )aste
%as been stabilised and matured. Before use6 t%e com"ost is c%ecked for contaminants to
ensure t%at it fulfils t%e "%ysical6 c%emical and biological re5uirements for commercial
com"ost=S4(A6 2,1,>.
-'1'-'-'- D!(o.2ositio* 2$o(!ss
&om"ost containers can be used to easily obtain t%e o"timal decom"osition conditions for
organic )aste by regulating t%e air6 %umidity and tem"erature during t%e com"osting "rocess
and t%us create t%e ideal environment for micro/organism develo"ment =bacteria6 "roto<oans6
fungi6 invertebrates>. Dood %andling of t%e com"ost "ile accelerates t%e decom"osition rate
)%ile also minimising t%e nutrient loss. Dood "ractices include cutting u" and s%redding t%e
organic )aste6 turning t%e "ile to increase aeration6 s"rinkling )ater on t%e "ile if it becomes
too dry =dusty )it% ants>6 and kee"ing t%e container closed during %eavy rains to "revent t%e
"ile from )ater logging =(rakas% et al 6 2,,0>.
23
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 24/50
aintaining t%e o"timal &9 ratio of 2$/!, may re5uire careful monitoring and
a""ro"riate %andling6 as nitrogen levels are often 5uite %ig% )%en com"osting domestic
organic )aste in containers due to t%e concentration of nitrogen/ric% matter and limited
aeration. -nder suc% conditions t%e com"ost becomes "utrid6 acidic and com"acts6 and its
5uality deteriorates. T%is t%en leads to %ig% odour emissions and t%e "revalence of anaerobic
conditions. Turning t%e "ile and adding dry "orous materials =carbon ric%>6 suc% as leaves6
sa)dust6 or stra)6 can easily rectify t%is "roblem. t s%ould be noted t%at if anaerobic
conditions "revail6 t%ermo"%ilic microbes may not develo"6 and conse5uently6 t%ermo"%ilic
tem"eratures may not be ac%ieved. ;o)ever6 in container com"osting t%is is not so crucial as
only domestic organic )aste is used6 rat%er t%an )aste from unkno)n sources t%at may
contain un)anted =i.e. %uman> "at%ogens andor agricultural residues t%at may contain cro"
diseases andor )eed seeds ='ong and Lin6 2,,2>.
-'1'-'-'1 Co*tai*!$ +!si"* a*+ #s!
&ontainers can be "ur"ose built =e.g. from bricks6 blocks6 "lastic barrels6 )icker baskets>
or constructed from recycled materials =e.g. oil drums6 "lastic barrels6 building materials>.
T%e s"ace re5uired for a com"osting site is a""ro8imately 1.$/2 m 2 "er %ouse%old. T%is
allocated area allo)s enoug% s"ace to "lace t)o containers side by side6 or to build t)o
c%ambers if using bricks or blocks =%eig%t 1m>E sufficient )orking s"ace s%ould be
maintained around t%e front of t%e containers. T%e c%ambers are filled se5uentially6 so t%at
)%en t%e second c%amber is full t%e com"ost in t%e first c%amber can be em"tied and t%e
mature com"ost stored until ready for use. n designing containers6 consideration %as to be
made for aeration vents6 drainage6 ground soil contact and over%ead "rotection.
&ement )as used in t%e construction of t%e double/c%amber bins alt%oug% ga"s )ere left
bet)een t%e blocks in t%e bottom to facilitate aeration =left )it%out mortar for tem"orary use>6
and t%en eac% c%amber )as covered )it% a )ooden lid. n some locations and in si8 sc%ools
larger versions consisting of t%ree %ig%/ca"acity c%ambers )ere also built and demonstrated.
But regardless of t%e ty"e of container selected6 some fundamental design "rinci"les need to
be considered including?
(ile com"ost directly on ground soil t%us ensuring drainage and allo)ing contact )it%
soil micro/organisms =in sealed containers "rovide drainage %oles and add fres%com"ost in eac% cycle to ensure micro/organisms are "resent>.
24
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 25/50
(rovide means of aeration in container )alls =%oles in drums or ga"s bet)een blocks>.
-se covers to close containers at nig%t and regulate com"ost "ile during day.
=rec%sel and Hun<e6 2,,1>.
-'1'-'1 I*<0!ss! (o<(o.2osti*"
n/vessel com"osting re5uires controlled moisture and air su""ly6 as )ell as mec%anical
mi8ing. T%erefore6 it is not generally a""ro"riate for decentrali<ed facilities. Alt%oug% t%e
com"osting "rocess seems like a sim"le6 "assive tec%nology6 a )ell/)orking facility re5uires
careful "lanning and design to avoid failure. n/vessel non flo) aerobic com"osting systems
t%at use reactors are "o"ularly termed mec%anicalC enclosedC or in/vesselC6 )%ile t%ose
t%at do not are often termed o"en systemsC. 7eactor Systems of n/ Iessel ty"e are t%ose in
)%ic% com"osting material is "laced for t%e "rocess. Denerally n:Iessel systems "rove
advantageous because of t%e follo)ing reasons
ra"id rate of decom"osition
"recise control of moisture6 aeration and tem"erature
5uicker odour removal
lesser area re5uirements
lesser "ersonnel re5uirements and
"est control.
T%e "rinci"le be%ind t%ese non flo) tec%ni5ues is to use batc% o"erated com"ost bo8es
t%at are no) available in t%e market. n t%e "rocess6 t%e )astes are loaded at t%e start of t%e
cycle and ty"ically remain in t%e bo8 reactor for 0 to 1 days. Aeration is usually controlled.
&uring is conducted in )indro)s for several mont%s. T%e above tec%ni5ue is t%e best solution
for laboratory scale studies = eenambal6 2,,!>.
-'1'1 E.!$"i*" (o.2osti*" 2$o(!ss!s
4merging trends include t%e "ractice of vermiculture and t%e use of effective micro/
organisms to accelerate t%e com"osting "rocess. Iermiculture is t%e use of )orms to digest
organic )aste into ric% %umus6 similar to com"ost6 t%at can t%en be a""lied in urban
agriculture. Local varieties of bot% surface and burro)ing eart%)orms can be used6 alt%oug%t%e latter are "articularly suited as t%ey not only digest organic matter but also modify t%e soil
25
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 26/50
structure. Iermiculture is "articularly suited to urban agriculture because it can be a""lied in
a variety of settings and at different scales. T%e "ractice is also used very often as "art of
integrated gardening in community building urban agriculture. ndeed6 broad/scale
vermiculture is )ides"read in ndia6 ndonesia and t%e (%ili""ines =DFA/-m)elt6 1333>6
)%ile t%e "ractice %as recently been gaining ground in &uba and Argentina =ubbeling and
Santandreu6 2,,!E Iiljoen and ;o)e6 2,,$>. n broad/scale vermiculture6 t%e eart%)orms are
introduced to organic )aste "iled in elongated ro)s t%at are covered )it% some form of
vegetative "rotection to "revent )ater logging =smail6 1330>
26
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 27/50
Tab! -'18 M!$its a*+ +!.!$its of (o<(o.2osti*"
A+0a*ta"!s Disa+0a*ta"!s=i.itatio*s
/ T%roug% co/com"osting6 a useful and safe
end "roduct is generated t%at combines
nutrients and organic material.
/ 4asy to set u" and maintain )it%
a""ro"riate training
/ (rovides a valuable resource t%at can
im"rove local agriculture and food "roduction
/ &an be built and re"aired )it% locally
available materials
/ Toilet "a"er is decom"osed
/ Lo) ca"ital costE lo) o"erating cost
/ (otential for local job creation and income
generation
/ 9o electrical energy re5uired
/ Long storage times
/ 7e5uires e8"ert design and o"eration
/ Limited control of vectors and "est
attraction
/ Labour intensive
/ Lo)er cost variants re5uires a large land
area =)%ic% is )ell located>
So#$(!8 %A)0o2!+ia, -9&9;
-'3 P!$fo$.a*(! a*+ 2$ob!.s of (o.2osti*"
&ontainer com"osting "roved to be %ig%ly effective for decom"osing organic )aste6
"articularly )%en good com"osting "ractices )ere follo)ed6 s"ecifically )%ere organic
materials )ere s%redded and t%e com"ost "ile fre5uently aerated. (roblems encountered
27
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 28/50
included com"ost com"action and "utrefaction6 lo) "artici"ant motivation and loss of t%e
actual com"osting site. uring t%e earlier "%ases6 some "roject "artici"ants eager to fill t%eir
containers )it% organic )aste invited t%eir neig%bours and friends to also use t%em. As t%e
containers )ere designed for individual %ouse%old use t%ey )ere ra"idly filled6 )%ic%
resulted in com"ost com"action and "utrefaction. 7emoving t%e to" layers and increasing
aeration of t%e remaining com"ost "ile remedied t%is. n "laces )%ere t%e larger ca"acity
tri"le/c%amber containers )ere used t%is "roblem did not occur =Akvo"edia6 2,1,>.
-'5 B!*!fits of Co.2osti*"
T%e recycling of urban organic )aste brings several ecological advantages t%at can
en%ance energy efficiency t%roug% carbon6 nutrient and )ater conservation in urbanlandsca"es =;olmgren6 2,,2>. T%ese advantages can be categorised as t%e micro/environment
benefits as t%ey relate directly to soil amelioration measures6 but in addition6 energy
efficiency s%ould also be considered in t%e broader sense to enca"sulate t%e )ider advantages
t%at can be accrued at national6 regional and international scales. For e8am"le6 recycling
organic )aste t%roug% com"osting in urban agriculture reduces t%e need to im"ort c%emical
fertili<ers and food stuffs. Furt%ermore6 )%en urban organic )aste recycling is decentralised
t%ere is reduced need for e8ternal in"uts suc% as e5ui"ment6 fuel and trans"ortation.
any urban areas are vast nutrient sinks as t%e recyclable nutrient "otential from organic
)aste is seldom e8"loited and t%us lost. T%is is com"ounded by t%e combination of soil
nutrient mining in rural and urban "roduction areas and t%e accumulation of urban organic
)aste in t%e dis"osal sites. n t%ese sites t%e mined nutrients accumulate in t%e urban areas6
largely t%roug% informal )aste dis"osal due to t%e inefficiency of formal )aste dis"osal
structures =rec%sel and Hun<e6 2,,1E &ofie6 2,,2>.
CHAPTER THREE
RESEARCH METHODOLOGY
T%e c%a"ter discusses e8tensively6 t%e met%odological "rocedure undergone in t%e
course of t%is researc% )ork. T%e researc% materials6 e5ui"ments and a""aratus for t%e study
28
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 29/50
"ur"ose )ere %ig%lig%ted. T%e )aste collection6 com"ost "re"aration "rocess and t%e "re/
c%aracteri<ation and "ost/c%aracteri<ation of t%e com"ost ra) material and t%e matured
com"ost are e8"lained in details.
1'& Mat!$ias
T%e main ra) materials used for "re"aration of com"ost are as listed belo)?
-rban )astes
Farm )astes and )eeds.
Additives suc% as green leaves6 co) dung6 urea6 matured com"ost or ric% loamy soil
)%ic% all serve as inoculums.
1'- E>#i2.!*ts, R!a"!*ts a*+ A22a$at#s
T%e e5ui"mentsa""aratus used in t%e "re"aration and c%aracteri<ation of com"ost are
?
&om"ost bin ='ell aerated containers>
Turner
"; metre
T%ermometer
Atomic Absor"tion S"ectrosco"y =AAS>.
rying oven
Furnace
;ot "late
Silica crucible
'atc% glass
Scrubber tubes
eioni<ed )ater
&oncentrated nitric acid =;9O!>6 0,@
&oncentrated %ydroc%loric acid =;&l>6 !0@
iluted ;&l
Tetrao8osul"%ate=vi>acid
Tetrao8o"%os"%ate=v>acid
Sodium %ydro8ide
;ydrogen (ero8ide =;2O2>
"olyvinyl alco%ol solution
9esslerNs reagent.
1'1 E?2!$i.!*ta P$o(!+#$!
T%e e8"erimental "rocedure involvesE )aste "re"aration="re/c%aracteri<ation>6
com"ost "re"aration and "rocess monitoring and sam"ling ="ost/c%aracteri<ation> of t%e finalcom"ost.
29
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 30/50
1'1'& Wast! 2$!2a$atio*
T%e first ste" in t%e e8"erimental study )as t%e collection of t%e )astes from different
sources. 7otten fruits )ere also included in t%e collection. Before "re"aration of t%e
com"osite sam"le6 %and sorting )as done to segregate un)anted materials like stra)6 "lastic
covers6 "ackaging materials etc. T%en a com"osite sam"le )as "re"ared and allo)ed to dry
for fe) days to adjust t%e moisture content to t%e desired levels. T%e dried sam"les )ere
s%redded manually into "ieces bet)een si<es 2 and ! cm. T%e "ur"ose of )%ic% is to %ave
good uniformity in %eating and to "rovide greater surface area for microbial attack. T%e
s%redded sam"le )as t%en analy<ed for various "%ysical6 c%emical and biological
c%aracteristics to get a roug% idea about t%e biodegradability of t%e sam"le.
1'1'- C6a$a(t!$isatio* of 7ast!s #s!+ fo$ (o.2osti*"
T%e c%aracteri<ation follo)s t%e dry as%ing tec%ni5ue for t%e detection of various elements
"resent in t%e sam"le. t describes t%e "rocedure for as%ing a variety of materials for subse5uent
determination of mineral nutrients by flame atomic absor"tion s"ectrosco"y.
1'1'-'& D$ as6i*" sa.2! 2$!2a$atio*
T%e met%od is a""licable to sam"les for t%e determination of various mineral nutrients
=(6 Fe6 Kn6 and n etc>. T%e sam"le "re"aration met%od and subse5uent analysis )ere
evaluated. T%e sam"les consisted of t%ree com"osite ra) material grou"s?
-rban )aste
&o) dung
Dreen leaves
T%e met%od consists of "re"aring an as% by using %eat and nitric acid to decom"ose t%e
organic matter6 and dissolving t%e inorganic residue in an a""ro"riate volume of dilute
%ydroc%loric acid.
P$o(!+#$!8
30
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 31/50
1. T%e amount of sam"les re5uired =about $ g of dry matter> )ere )eig%ed into a
crucible. crucible )eig%t6 and crucible "lus sam"le )eig%t )ere noted.
2. T%e sam"les )ere dried in an oven for about 1* %ours =overnig%t> at 1,$o&. crucible
"lus dry sam"le )eig%t )as noted.
!. T%e sam"les )ere "laced in t%e furnace set to 2,,o& )it% allo)ance for t%e smoke to
esca"e.
. As t%e smoking )as reducing6 t%e furnace tem"erature )as raised by $,o increment
$. Ste" )as re"eated until t%e tem"erature reac%ed !$,o&6 t%en furnace door )as t%en
closed and t%e tem"erature set to $,o&6 and as% for anot%er 1* %ours =overnig%t>.
*. T%e sam"les from t%e furnace )ere allo)ed to cool6 'etted )it% )ater =;2O> and
sufficient ;9O! added to cover t%e as% =ty"ically 2/ ml>. T%is )as t%en covered )it%
a )atc% glass and reflu8 on a %ot "late for about 1 %our6 t%e )atc% glass )as t%en
removed
0. Ste" * )as re"eated until a )%ite as% is obtained.
+. 2/$ ml diluted ;&l )as added and t%e as% dissolved by gently boiling t%e solution6cooled and made u" to t%e a""ro"riate volume )it% ;2O.
3. T%e various elements )ere analysed by flame atomic absor"tion s"ectro"%otometry.
1'1'-'- D!t!$.i*atio* of (a$bo* (o*t!*t
T%e analysis of &arbon content in t%e )aste materials follo)s t%e "rocedure described
belo)
2 g of t%e )aste sam"le )as )eig%ed and mi8ed )it% a tetrao8osul"%ate=vi>acid and
tetrao8o"%os"%ate=v>acid
T%e "re"ared sam"le )as t%en combusted in a furnace at 1!$,o& in an O8ygen/ric%
atmos"%ere )%ere all t%e &arbon content )as converted to &arbon=iv>o8ide =&O2>
31
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 32/50
T%is )as t%en "assed t%roug% scrubber tubes to remove interferences suc% as &%lorine
gas and )ater va"our
T%e &arbon=iv>o8ide "roduced )as t%en collected in Sodium %ydro8ide =9aO;>
solution t%roug% )%ic% its gravimetric analysis )as "erformed.
G$a0i.!t$i( A*asis
1'1'1'1 D!t!$.i*atio* of *it$o"!* (o*t!*t
T%e analysis of 9itrogen content in t%e )aste materials follo)s t%e "rocedure
described belo)
$ g of t%e )aste sam"le )as )eig%ed into a digestion flask
ml of tetrao8osul"%ate=vi>acid )as added and t%e mi8ture )as %eated at !,o& for $
minutes
1$ ml of !,@ %ydrogen (ero8ide solution =; 2O2> )as added t%roug% t%e ca"illary
funnel6 maintaining t%e tem"erature
After 1, minutes6 t%e digestion is com"leted and t%e mi8ture )as carefully )as%ed
)it% distilled )ater
T%e mi8ture )as left to cool before being made u" to 1,, ml by distilled )ater.
,.$ ml ali5uot of t%e digest )as )it%dra)n and mi8ed )it% 2.$ ml of ,.1 gl
"olyvinyl alco%ol solution and 1.,,ml of 9esslerNs reagent.
T%is solution )as t%en analysed under t%e Atomic Absor"tion S"ectrometer
T%e absorbance obtained )as converted into concentration by means of a linear
calibration curve.
1'1'1 Co.2osti*" 2$o(!ss
32
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 33/50
T%e "re"aration of com"ost follo)ed t%e Turned 'indro)s met%od. A )ooden
com"ost bin constructed for good aeration )as "ut in "lace. T%e urban )aste )as manually
se"arated and t%en "iles of mi8ed solid )aste )as used and t%e re5uired o"erating condition
of moisture =,/*,@ ))>6 tem"erature =!2/*,o&> and air )as maintained t%roug%out t%e
com"osting "eriod.
&ollected )aste )as broug%t to t%e laboratory )%ere it )as c%ecked to ensure it is of
sufficient 5uality. t )as t%en be s%redded and "iled into )indro)s6 )%ic% are elongated "iles
s%a"ed for ideal com"osting. (ro"er aeration )as also ensured by suitable mi8ing of t%e
initial material and regular agitation =turning>. ecom"osition continued until t%e )aste %as
been stabili<ed and matured. After )%ic%6 t%e com"ost )as c%ecked for contaminants to
ensure t%at it fulfills t%e "%ysical6 c%emical and biological re5uirements for commercial
com"ost =S4(A6 2,1,>. T%e tem"erature is an im"ortant indicator for identifying t%e "rocess
stage during com"osting. Ty"ically6 t%e tem"erature of com"osting material rises during t%e
initial days and stays at an elevated tem"erature for some days =T%ermo"%ilic conditions i.e.
above $o&> before dro""ing gradually. &onstant turning )as t%erefore ensured to maintain
an o"timum o"erating tem"erature.
Tab! 1'&8 Co.2ositio* of t6! t7o +iff!$!*t 7ast! .i?t#$!s fo$ t6! (o.2osti*" 2$o(!ss
MI@TURE= C& C-
CONSTITUENT
-rban 'aste =kg> 1.$, 2.,,
&o) ung =kg> ,.!, ,.,
Dreen Leaves =kg> 1.$ 1.1
33
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 34/50
1'1'3 P$o(!ss .o*ito$i*" a*+ sa.2i*"
T%e "rocess of com"osting )as monitored )it% great attention. T%e com"ost )as
turned as and )%en re5uired to ensure uniform mi8ing and "ro"er aeration. T%e "; and
tem"erature sam"ling )as done once in every four days. T%e final com"ost sam"le )as
analy<ed for nutrient values6 "%ysical6 c%emical and biological c%aracteristics. T%e collected
sam"les )ere oven dried6 grinded6 fine sieved before analysis. T%e analyses )ere done for a
score of "%ysical and c%emical "arameters like ";6 &9 7atio6 %eavy metals6 4lectrical
conductivity etc =eenambal et al 6 2,,!>.
CHAPTER FOUR
RESULTS AND DISCUSSION
3'& R!s#ts
T%e results obtained in t%e course of t%e researc% )ork ranging from t%e )aste
"re"aration stage6 to t%e "re/c%aracteri<ation of t%e )aste6 t%roug% to t%e com"osting "rocess
alongside "rocess monitoring and sam"ling and finally to t%e "ost/c%aracteri<ation "rocess of
t%e matured com"ost )ere as s%o)n in Tables .1 / .$ and gra"%ically re"resented in
Figures .1 / .0 res"ectively.
34
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 35/50
Table .1 s%o)s t%e c%emical com"osition of t%e )aste materials used for
com"osting6 Table .2 s%o)s t%e nutrient values of com"osite )aste materials before
&om"osting6 Tables .! and . describes t%e (%ysical "ro"erties of t)o different com"ost
materials during t%e com"osting "rocess6 )%ile Table .$ s%o)s t%e nutrient value of t%e final
com"ost. T%e com"arison bet)een t%e &arbon to 9itrogen content of eac% of t%e )aste
material used )ere as re"resented in Figure .16 Figure .2 s%o)s t%e nutrient values of
com"osite )aste before com"osting )%ile t%at for t%e com"ost sam"les is s%o)n in Figure .0.
T%e correlation bet)een t%e Tem"erature6 "; of t%e t)o com"osting materials )it%
time )ere as re"resented in Figures .! and . and Figures .$ and .* res"ectively.
Tab! 3'&8 C6!.i(a (o.2ositio* of 7ast! .at!$ias #s!+ fo$ (o.2osti*"
&%aracteristics -rban )aste &o) dung Dreen leaves
"; *.10 0.23 0.,1
4& =Js cm/1> 12+ !2+ *1
Organic carbon =@> 2!.1, 1,.$, 13.,*
9itrogen =@> ,.,2$ ,.1 2.11
(%os"%orus =@> 1.$2 ,.2, ,.,0
35
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 36/50
(otassium =@> ,.!$ ,.!* 1.*$
&? 9 ratio 32.,, 2$.*1 3.,!
Fe =mgL> 0.33 0.,2 1!.12
Kn =mg kg/1> 2.3! ,.202 ,.1*+
&u =mg kg/1> ,.!$0 ,.2* ,.!,
Tab! 3'-8 N#t$i!*t 0a#!s of (o.2osit! 7ast! b!fo$! (o.2osti*"
Mi?t#$! Ca$bo* Nit$o"!* P6os26o$o#s C=N Ratio
C& 2+.*+ ,.!, ,.1! 3$.*
C- 2*.$, ,.!+ ,.!+ *3.0
Tab! 3'18 Bio<+!"$a+atio* of .i?t#$! C&
Da=
Pa$a.!t!$ & &9 &3 & -- -
A.bi!*t T!.2!$at#$! %o&> !,.,, 20.,, 20.,, 20.,, 2+.,, 2+ .,, 2$.,,
Co.2ost T!.2!$at#$! %o&> 20 .,, .,, !$.,, 2+.,, 2+.,, 2+ .,, 20.,,
2H $.0 *.+3 0.2, 0.* 0.0, 0.+1 0.3,
36
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 37/50
Tota Soi+s %@> $2.,, $,.,, $.,, $1.,, $!.0, $*.,, $3.,,
Tab! 3'38 Bio<+!"$a+atio* of .i?t#$! C-
Da=
Pa$a.!t!$ & &9 &3 & -- -
A.bi!*t T!.2!$at#$! %o&> !,.,, 20.,, 20.,, 20.,, 2+.,, 2+ .,, 2$.,,
Co.2ost T!.2!$at#$! % o&> 2* .,, +.,, !*.,, !,.,, 23.,, 2+ .,, 20.,,
2H $.+ *.03 0.21 0.!, 0.!$ 0.* 0.*$
Tota Soi+s %@> $$.,, +.,, .,, $,.,, $2.,, $*.,, *,.,,
Tab! 3'58 N#t$i!*t 0a#!s of t6! .at#$!+ soi+ #$ba* 7ast! (o.2ost'
Mi?t#$! Ca$bo* Nit$o"!* P6os26o$o#s Potassi#. C=N Ratio 2H Co*+#(ti0it
%s (.<&;
C& 2!. ,.*! ,.1 ,.!$ !0.1 0.3, 13$,
C- 2!.1* ,.0$ ,.!+ ,.$ !,.++ 0.*$ 220,
37
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 38/50
Fi"#$! 3'&8 Ca$bo* to *it$o"!* (o*t!*t (o.2a$iso* of 7ast! .at!$ias #s!+
Fi"#$! 3'-8 N#t$i!*t 0a#!s of (o.2osit! 7ast! b!fo$! (o.2osti*"
38
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 39/50
9 5 &9 &5 -99
5
&9
&5
-9
-5
19
15
39
Time (Days)
T e m p e r a t u r e ( o C )
39
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 40/50
Fi"#$! 3'18 T!.2!$at#$! ti.! (o$$!atio* of sa.2! (& +#$i*" (o.2osti*" 2$o(!ss
9 5 &9 &5 -99
5
&9
&5
-9
-5
19
15
39
35
59
Time (Days)
T e m p e r a t u r e ( o C )
Fi"#$! 3'38 T!.2!$at#$! ti.! (o$$!atio* of sa.2! C- +#$i*" (o.2osti*" 2$o(!ss
40
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 41/50
, $ 1, 1$ 2,,
1
2
!
$
*
0
+
Time (Days)
p H
Fi"#$! 3'58 2H ti.! (o$$!atio* of sa.2! C& +#$i*" (o.2osti*" 2$o(!ss
41
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 42/50
, $ 1, 1$ 2,,
1
2
!
$
*
0
Time Days)
p H
Fi"#$! 3'8 2H ti.! (o$$!atio* of sa.2! C- +#$i*" (o.2osti*" 2$o(!ss
42
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 43/50
Fi"#$! 3'8 N#t$i!*t 0a#!s of t6! .at#$!+ soi+ #$ba* 7ast! (o.2ost'
3'- Dis(#ssio* of R!s#ts
T%e c%emical com"ositions of various organic materials used for "re"aring t%e
com"ost as given in Table .1 describes t%e urban )aste as being slig%tly acidic in nature =";*.10> and )as fairly lo) in 9itrogen =9> =,.,2$@>6 )it% (%os"%orous =(> and (otassium =H>
43
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 44/50
%aving 1.2$@ and ,.!$@ res"ectively. T%e organic carbon =&> )as 2!.1@ )it% a &? 9 ratio
of 32.,,. Dreen leaves )ere ric% in 9 =2.11@> and )as used to su""lement 9itrogen to
initially counter t%e nitrogen de"letion during t%e )aste "re"aration stage. &o) dung )as
used as an additive or inoculum for t%e com"ost treatments. t served mainly as a starter
material for com"osting. t also en%ances t%e decom"osition of cellulosic "lant material and it
%ad ,.1@ 9 )it% a &?9 ratio of 2$.*1
T%e data on t%e nutrient values of t%e matured solid urban )aste com"ost are as given in
Table .$. T%e "; of t%e t)o com"osts =&1 and &2> )ere slig%tly alkaline6 )it% %ig%est ";
being recorded in &1 =0.3,>. T%e results of study concurred )it% t%e observation of
=T%om"son and Troe%6 130+> )%o re"orted t%at t%e munici"al com"ost )as slig%tly alkaline
in nature. T%e 9itrogen content )as %ig%er in &2 =,.0$> due to %ig% 9itrogen content in t%e
initial )aste materials.
T%e com"arison of Tables .2 and .$ s%o)ed t%at t%e %ig%er t%e &arbon6 & content in
t%e com"osting material6 t%e lo)er t%e com"ost 5uality )%ic% is determined by t%e &9
content. 4ffective com"osting t%erefore %as to do )it% t%e a""ro"riate &9 "ro"ortion from
t%e )aste "re"aration stage.
According to ';O =13+3>6 t )as revie)ed t%at effective com"osting takes "lace by
maintaining a tem"erature range of !2/*,o&. T%e rig%t &9 dosage %el"s in attaining t%is
o"timal tem"erature6 t%is could be seen in Tables .! and .. T%e & 1 sam"le )it% an initial
%ig%er &9 content =3$.*> attained a ma8imum com"osting tem"erature of o& )%ile
Sam"le &2 )it% fairly lo) &9 content =*3.0> attained a slig%tly %ig%er com"osting
tem"erature of +o&. T%e Table also s%o)ed increased tendency of a slig%t alkalinity )%ic% is
t%e c%aracteristic "ro"erty of a good com"ost as t%e &9 content reduces. T%e %ig%er
9itrogen content com"osite )aste material &1 s%o)ed a muc% %ig%er com"osting tem"erature
range of 22o& =2*/+o&> com"ared to 10o& =20/o&> of t%e lo)er 9itrogen content
com"osite )aste material &2 =Tables .! and .$>
T%e figures furt%er e8"lained t%e conce"t be%ind t%e com"osting "rocess. Figure .1
s%o)ed t%at t%e 9itrogen deficiency of t%e urban )aste )%ic% is majorly &arbon constituted
could be made u" for by t%e addition of Dreen leaves )%ic% are 9itrogen/ric%6 t%us ensuring
ade5uate 9itrogen nutrient value in t%e com"osite )aste before com"osting as s%o)n in
Figure .2. Figure .! and . s%o)s t%e tem"erature = o&> variation )it% time =ays>. Figure
.! s%o)s t%e stee" decrease in com"osting tem"erature of sam"le &16 )%ic% is 9itrogen
deficient com"ared to a gradual decrease observed in sam"le & 2 of %ig%er initial 9itrogen
44
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 45/50
content as s%o)n in Figure .. A gradual tem"erature decrease is a "rere5uisite to an
effective com"osting "rocess6 as t%e )aste materials are being decom"osed at a muc%
elevated tem"erature for a longer duration of time.
&onclusively6 t%e enric%ment of com"ost )it% additives increased t%e decom"osition
rate6 )%ic% may be due to availability of essential nutrients for t%e increased biological
activity. From t%is investigation it can be stated t%at enric%ment of urban )aste )it% co)
dung6 organic nitrogen6 microbial culture and micronutrients resulted in value added com"ost.
CHAPTER FIVE
CONCLUSION AND RECOMMENDATIONS
5'& Co*(#sio*
45
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 46/50
T%e 48"erimental study of biodegradation of -rban Solid 'astes %as establis%ed t%e
follo)ing significant details.
T%e "rocess of com"osting is significantly affected by constituents like &9 ratio6
moisture content6 ";6 electrical conductivity6 total solids and tem"erature. From t%e analysis of &9 ratio6 t%ere is a noticeable reduction bet)een t%e t)o
com"ost sam"les &1 =;ig% &arbon content> and &2 =Lo) &arbon content>6 )%ic%
im"lies t%at addition of e8cessive carbon content6 is not encouraged.
T%e results of t%e study clearly indicated t%at t%e Biodegradation of solid urban
)astes can transform garbage to enric%ed com"osts. T%is is an im"ortant message of "ractical
significance if ado"ted by urban farmers. T%ereby t%e soil %ealt% and in turn t%e "roductivity
of soil can be maintained for future agriculture. T%is "oint gains im"ortance given t%e fact
t%at t%e 5uantum of cultivable land is fast d)indling es"ecially in t%e develo"ing countries.
T%erefore t%e essence of t%e "resent study is t%at t%e urban farmers s%ould be motivated to
"ractice urban )aste recycling t%roug% bioremedial measures.
5'- R!(o..!*+atio*s
As a result of %a"%a<ard manner of dum"ing of refuse )%ic% is "osing a serious
environmental t%reat to t%e environment6 an effective system of solid )aste management is
t%e need of t%e %our and s%ould be environmentally and economically sustainable.
&om"osting )%ic% is t%e sim"lest yet best "rocess for solid )aste management %as gone a
long )ay in ma8imising environmentally sound )aste reuse and recycling
;o)ever6 t%e follo)ing recommendations )ere t%ereby made to)ards )aste
minimi<ation6 ma8imising environmentally sound )aste reuse and recycling as )ell as
"romoting environmentally sound )aste dis"osal?
uc% attention s%ould be "laced on biological "rocess re5uirements during
com"osting "rocesses
T%ere s%ould be furt%er investigation on t%e emerging com"osting "rocesses suc% as
t%e vermiculture and t%e use of effective micro/organisms to accelerate t%e
com"osting "rocess
T%e standards and norms for %andling munici"al solid )astes )%ic% %ad reduced
occu"ational %ealt% and environmental im"acts substantially in industriali<ed
countries s%ould be ado"ted by t%e develo"ing countries to tackle bot% t%e
environmental and t%e agricultural "roblems
46
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 47/50
REFERENCES
Ali . =2,,>? Sustainable &om"osting? &ase studies and guidelines for develo"ing
countries. '4&. Loug%boroug% -niversity6 -H. (". 12.
Allison .6 ;arris (.#.&.6 ;ofny/&ollins A.;. and Stevens '. =133+>? A 7evie) of t%e -se of
-rban 'aste in (eri/-rban nterface (roduction Systems6 ;enry oubleday 7esearc%
Association6 &oventry6 -H.
47
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 48/50
As%a A.6 Tri"at%i A. H. and Soni (. =2,,+>? Iermicom"osting? A Better O"tion for Organic
Solid 'aste anagement6 #ournal of ;uman 4cology6 2=1>? $3/*.
Bradford6 A. =2,,$>? GSolid 'aste anagement and -rban AgricultureG. n Feeding cities in
Anglo"%one Africa )it% urban agriculture? &once"ts6 tools and case studies for
"ractitioners6 "lanners and "olicy makers6 nternational (otato &entre : -rban ;arvest6
Lima6 (eru.
&%ina &ouncil for nternational &oo"eration on 4nvironment and evelo"ment =&&&4>
=2,,0>? Environmental and Health Challenges of Mni!i"al #olid $aste
in China.
&ofie O.O.6 Dordana Hranjac/Berisavljevic and (. rec%sel =2,,$>? T%e use of %uman )aste
for "eri/agriculture in nort%ern D%ana. 7ene)able Agriculture and Food Systems? 2,=2>E
0!:+,.
&ointreau S.6 2,,1? eclaration of "rinci"les for sustainable and integrated solid )aste
management6 'orld Bank6 'as%ington6 .&.6 "".
Da0i+ N' B', a*+ Da0i+ E' B' %-9&9;8 T%e 4co*omics of unici"al Soi+ 'aste6 O8ford#ournals6 1, =2>? 11!/1$,.
ubbeling . and Santandreu A.=2,,!>? 7ecycling Organic 'astes in -rban Agriculture?
Duidelines for unici"al (olicymaking on -rban Agriculture 9o$. nternational
evelo"ment 7esearc% &entre6 Otta)a6 &anada.
rec%sel6 (. and Hun<e6 . =2,,1>? 'aste &om"osting for -rban and (eri/urban Agriculture?
&losing t%e 7ural/-rban 9utrient &ycle in Sub/Sa%aran Africa. nternational 'ater
anagement nstitute6 Food and Agriculture Organisation and &AB (ublis%ing6
'allingford6 -H.
4ncyclo"edia of (ublic ;ealt% =2,1,>? unici"al Solid 'aste
Faisal . ;. =2,,$>? Solid 'aste anagement in evelo"ing &ountry? To)ards a Sustainable
Solution6 e"artment of -rban 4ngineering6 -niversity of Tokyo6 Tokyo6 #a"an.
48
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 49/50
Dautam S. (.6 Bundela (. S.6 (andey A. H.6 #ain 7. H.6 eo (. 7.6 H%are S. H.6 A)ast%i . H.
and Surendra S. =2,,3>? Biodegradation and 7ecycling of -rban Solid 'aste6 American
#ournal of 4nvironmental Sciences 6 $ =$>? *$!/*$*.
DFA/-m)elt =1333> -tilisation of Organic 'aste in =(eri/> -rban &entres6 Dermany.
Dos% S. 7.6 =2,,>? n/vessel com"osting of %ouse%old )astes6 #ournal of )aste management
2*? 1,0,/1,+,.
;eimlic% #. 4.6 ;ug%es H. L. and &%risty A. . =2,,1>? ntegrated Solid 'aste anagement ,
O%io State -niversity Fact S%eet &ommunity evelo"ment "".1,*/2,$.
;olmgren . =2,,2> (ermaculture? (rinci"les and (at%)ays Beyond Sustainability.
;olmgren esign Services6 Iictoria6 Australia.
;oorn)eg .6 T%omas L.6 and Otten L. =1333>? &om"osting and its a""licability in
develo"ing countries. -rban 'aste anagement 'orking (a"er +6 -rban evelo"ment
ivision6 'orld Bank6 'as%ington6 &. "" *.
smail S.A. =1330>? Iermicology? T%e Biology of 4art%)orms6 Orient Longman6 ;yderabad.
Lardinois . and van de Hlundert A. =133!>? Organic 'aste. -rban Solid 'aste Series 1?
O"tions for small/scale resource recovery6 Douda6 9et%erlands.
eenambal T.6 Saravannan S. and -ma 7. 9. =2,,!>? Study on Biodegradation of Fruit 'aste
Aerobic &om"osting.
Onibokun A.D. =1333>? anaging t%e onster? -rban 'aste and Dovernance in Africa.
nternational evelo"ment 7esearc% &entre6 Otta)a6 &anada.
(rakas% -.;.B.6 .I. B%argavi I.7.7. (arama and .&. (reet%u =2,,0>? Bioremedial
recycling of solid )aste. (roceeding of t%e nternational &onference on Sustainable Solid
'aste anagement6 &%ennai6 ndia6 ""? 2+3/23$.
49
7/25/2019 Biodegradation of Urban Solid Waste
http://slidepdf.com/reader/full/biodegradation-of-urban-solid-waste 50/50
Samantha L. J. (2007): Environmental and Health Challenges of Municipal
Solid Waste in China.
Scottish Environmental Protection Agency (SEPA) (!"!)# $pen Windro%
Composting# &esidual Waste 'reatment 'echnologies ational Waste
Strategy Scotland.
T%om"son6 L.. and F.7. Troe%6 130+. Soils andSoil Fertility. cDra) ;ill6 9e) ork6 ""?
$1*.
-94( =2,,>? 'aste anagement (lanning6 an 4nvironmentally Sound A""roac% for
Sustainable -rban 'aste anagement / An ntroductory Duide for ecision/makers.
nternational 4nvironmental Tec%nology &enter =4T&>6 -nited 9ations 4nvironment
(rogramme6 ivision of Tec%nology6 ndustry and 4conomics.
Iiljoen A. and ;o)e #. =2,,$>? G&uba? laboratory for urban agricultureG. n Iiljoen6 A. =ed.>
=2,,$> &ontinuous (roductive -rban Landsca"es? esigning -rban Agriculture For
Sustainable &ities. Arc%itectural (ress6 4lsevier6 O8ford6 "". 1*/131.
'ong6 S.. and S.S. Lin =2,,2>? &om"osts as sol su""lement en%ance "lant gro)t% and fruit
5uality of stra) berry. #ournal of (lant 9utrition6 2$? 22!/22$3.
i6 B.6 K. 'ei and ;. Liu =2,,$>? ynamic simulation for domestic solid )aste com"osting
"rocesses. #ournal of American Science6 1? !/$.
Kurbrugg6 &. and resc%er S. 2,,2. Solid 'aste anagement : biological treatment of
munici"al solid )aste. SA94& 9e)s 9o. $6 uebendorf6 S)it<erland.
%tt"?en.)iki"edia.org)ikiBiodegradation% retrieved 1,t% February6 2,1,.
%tt"?))).akvo"edia.org6 retrieved 1,t% February6 2,1,.
Recommended