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Geoenvironmental Engineering


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Bangalore generates around 3,500 tons of municipal solid waste (MSW) per day. The current waste management practices involve preliminary mechanical and biological treatment before landfilling. Assessment of the waste management practices followed by the municipality by using life cycle analysis (LCA) is presented in this study. LCA is also used in the study to explore alternatives to the current practices and handle the waste in a more sustainable way. The analysis is performed in terms of material flow, energy flow, and the impacts of waste processing on the environment. Five impact categories consisting of global warming, acidification, eutrophication, human toxicity, and aquatic ecotoxicity potentials were investigated. The result presents the comparison of open dumping of MSW (which was practiced earlier) with the existing integrated waste management (IWM) system. Results also show that the environmental impact of IWM system with a bioreactor landfill having an energy recovery facility is lesser than the above two cases.
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Geo-Congress 2019 GSP 312 125
Life Cycle Analysis as a Tool to Assess the Sustainability of Waste Management Practices
in Bangalore City
P. Sughosh1; N. Anusree2; and G. L. Sivakumar Babu3
1Center for Sustainable Technologies (CST), Indian Institute of Science, Bangalore 560 012,
India. E-mail:
2Dept. of Civil Engineering, College of Engineering, Trivandrum, Thiruvananthapuram 695016,
India. E-mail:
3Dept. of Civil Engineering, Indian Institute of Science, Bangalore 560 012, India. E-mail:
Bangalore generates around 3,500 tons of municipal solid waste (MSW) per day. The current
waste management practices involve preliminary mechanical and biological treatment before
landfilling. Assessment of the waste management practices followed by the municipality by
using life cycle analysis (LCA) is presented in this study. LCA is also used in the study to
explore alternatives to the current practices and handle the waste in a more sustainable way. The
analysis is performed in terms of material flow, energy flow, and the impacts of waste processing
on the environment. Five impact categories consisting of global warming, acidification,
eutrophication, human toxicity, and aquatic ecotoxicity potentials were investigated. The result
presents the comparison of open dumping of MSW (which was practiced earlier) with the
existing integrated waste management (IWM) system. Results also show that the environmental
impact of IWM system with a bioreactor landfill having an energy recovery facility is lesser than
the above two cases.
Municipal solid waste (MSW) management in India is a serious challenge considering the
amount of waste that is generated on a daily basis. According to Karnataka State Pollution
Control Board (KSPCB annual report 2013), Bangalore generates around 3500 tons/day of MSW
and has a collection efficiency of 85%. Bangalore has witnessed a rapid growth in its urban
population and waste generation rate in the last decade. The treatment system in Bangalore has
evolved from the open dumping of waste a decade ago (Ramachandra et al. 2007) to a
combination of waste treatment systems involving segregation, windrow composting and
controlled landfilling into the conventional landfills in the present times. Around eleven mixed
waste processing units and seven mixed waste processing units with landfills have been set up by
the Municipality to achieve 100% processing of MSW (KSPCB annual report, 2013). Even
though there has been a considerable increase in the processing capacity of the generated waste
in the recent years, the data about the actual waste processed is unavailable. Therefore, it is
assumed that both open dumping and waste treatment at integrated waste management (IWM)
units are prevalent in Bangalore currently. The impact of the present or the earlier waste
management practices in Bangalore has not been assessed until now. Such studies would help in
understanding the environmental burdens associated with the waste treatment systems. Life cycle
analysis (LCA) of the processes employed in the waste treatment facilities would help in
understanding their potential impacts and thereby assist in making important policy decisions.
The environmental impacts of MSW management systems can be assessed by using LCA
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tools (Chaya and Gheewala, 2007; Mendes et al. 2003). Several LCA studies on the management
practices involving open dumping, composting and landfilling (both conventional and bioreactor
type) are reported in the literature. Hong et al. (2010) assessed four solid waste management
scenarios through LCA in China and reported that the landfills contributed considerably to the
global warming potential due to direct methane gas emissions. However, electricity recovery
from methane gas was the key factor in reducing the potential impact of global warming. Sharma
et al. (2017) studied six solid waste management scenarios in Mumbai (India) and concluded that
the scenario with the combination of recycling, composting and landfill had the least
eutrophication and least human toxicity potential. They also stated that significant environmental
savings could be achieved with the help of energy recovery facility in all the waste management
scenarios. Other studies by Damgaard et al. (2011) and Babu et al. (2014) also had similar
findings about the energy recovery systems in bioreactor landfills.
In this study, LCA is used to access the performance of the waste management practices that
are currently proposed in the Bangalore city. Also, the potential benefits of incorporating the
bioreactor landfills in place of the proposed conventional landfills are also evaluated in the study.
Three MSW treatment scenarios are considered here. The first scenario considers processing
only a small fraction of waste collected by means of composting (3.14%) and the rest of the
waste is directly discarded by open dumping (96.86%). This scenario was widely prevalent in
Bangalore in the late 2000’s (Ramachandra et al. 2007). The second scenario considers the
processing of the collected waste by preliminary mechanical and biological treatment such as
mechanical sorting and windrow composting prior to landfilling. This scenario represents the
present status of Bangalore city with the installed waste processing capacity almost equivalent to
the generation rate. The third scenario is similar to the second, except the waste is landfilled in
bioreactors instead of a conventional landfill. The gas generated from the bioreactor landfill is
used for power generation while in the open dumps and conventional landfills it is let off directly
to the atmosphere.
The treatment systems considered in each of the scenarios are given below.
Scenario 1: [Open dumps] (96.86%) and [Segregation + Composting] (3.14%)
Scenario 2: IWM system [Material Recovery Facility (MRF) + Composting + Conventional
landfill +leachate treatment]
Scenario 3: IWM system [MRF + Composting + Bioreactor landfill +leachate treatment
+Gas recovery and power generation]
Fig. 1. Flowchart of the scenario 1
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Geo-Congress 2019 GSP 312 127
Scenario 1: The flowchart showing the handling of MSW in scenario 1 is given in Fig. 1.
Most of the MSW collected is disposed directly into open dumps, and only a fraction of MSW is
processed by composting, and then the rejects are discarded in open dumps. The gaseous
emissions and leachate generated (in composting units and open dumps) are let out without any
treatment into the environment.
Scenario 2: The MSW is fed into trommels of varying size (200 and100mm) to recover the
recyclable and combustible materials. The MSW passing through 100mm trommel is windrow
composted. The combustible materials are then compacted to produce refuse derived fuel (RDF).
The mechanically biologically treated (MBT) waste thus obtained is then passed through the 16 -
4mm trommels. The retained material (MBT waste) is then disposed in a conventional landfill.
The material passing through 4mm is compost and is sold as a natural fertilizer. The landfill gas
(LFG) is let out directly while the leachate generated is treated before discharging into the
natural water bodies.
Fig. 2. Flowchart of scenario 2 and 3
Scenario 3: All unit processes here are similar to scenario 2. Bioreactor landfill with power
generation from LFG produced is considered in this scenario. Fig. 2 shows the flowchart of the
scenario 2 and 3.
Fig. 3. System boundary of scenario 1, 2 and 3
In this paper, the LCA is carried out based on the International Organization for
Standardization (ISO) 14040:2006 methodology. It consists of four phases, which include, goal
definition and scoping, inventory analysis, life cycle impact assessment and interpretation or
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improvement analysis.
Table 1. Unit processes showing the material/energy flow in different scenarios.
1, 2, 3
<100mm MSW
Electricity; 3.2 kW/T
Indirect emissions
1, 2, 3
Diesel; 3.21L/T
Gaseous emissions
1, 2, 3
<100mm MSW
1, 2, 3
Gaseous emissions;
ammonia gas
1, 2, 3
Electricity 0.88 kW/T
Indirect emissions
1, 2, 3
Diesel; 0.47 L/T
Gaseous emissions
1, 2, 3
Open dumping
MSW and MBT waste
Leachate; (generation is
proportional to rainfall);
COD, BOD, NH3, Ni, Zn
Diesel; 0.88 L/T
Gaseous emissions
LFG; CH4, CO2, SO2, NOx,
H2S and VOCs
Bioreactor landfill
MBT waste
Leachate; generation is 10%
of rainfall; COD, BOD,
NH3, Ni, Zn
2, 3
LFG; CH4, CO2, SO2, NOx,
H2S and VOCs
2, 3
Diesel; 0.9 L/T and 2L/T
for 2 and 3 respectively
Gaseous emissions
2, 3
2, 3
2, 3
Treated Leachate
2, 3
Electricity; 0.244 MJ/T of
Indirect emissions
2, 3
Power generation
LFG; 90% collection
efficiency and calorific
value of methane as 50
Electricity and Gaseous
The goal of this study is to evaluate the above mentioned MSW management scenarios using
LCA methodology and to estimate its impact on the environment. One tonne of MSW is selected
as the functional unit for comparison of MSW management systems. The system boundaries
considered for all the scenarios are given in Fig. 3.
MSW, raw materials (liners, clay, gas collection system and leachate collection system) and
energy (electricity and fuel) are considered as inputs to the system. The output from the system is
the compost, refuse derived fuel (RDF), gaseous emissions and the leachate from the composting
yards/ open dumps/ landfills. The emissions can be from both the foreground systems like
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composting and landfill systems (direct emissions) and from the background systems (indirect
emissions) during the production and consumption of diesel and electricity.
Table 2. Physical composition of MSW in Bangalore (Chanakya et al. 2010)
Composition (% by mass)
The volume of daily cover in a landfill is estimated to be 0.1% of the volume of the deposited
waste and the volume of the cover system is estimated to be 0.08% of the volume of waste
(CPHEEO Manual 2000). The scenarios 2 and 3 consists of leachate collection and treatment
system. Scenario 3 consist of a gas collection system wherein the gas collected is used to
generate power. Table 1 shows the material/energy flow in different unit processes considered in
the study.
Fig. 4. Mass balance of MSW -Scenario 2 & 3
Input analysis
The physical composition of MSW generated in Bangalore is given in Table 2. The organic
content of MSW is taken as 72% as per Chanakya et al. (2010). The MSW after entering the
system undergoes physical, mechanical and biological treatment during which it transforms into
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different by-products. The mass balance of MSW in the system with its different by-products are
shown in Fig. 4 (CPHEEO Manual 2014). The diesel requirement for open dumps, conventional
landfills and bioreactor landfills are assumed to be 0.88 L/T, 0.9 L/T and 2 L/T respectively
(Damgaard et al. 2011).
Diesel and electricity requirement to process one ton of waste in material recovery units and
composting units are taken as 3.21L and 3.2kWh and 0.47L and 0.88 kWh respectively (Sharma
et al. 2017).
Table 3 shows the four impact categories associated with the indirect environmental
emissions resulting from the production of electricity and diesel (GaBi 2014).
Compost emissions: The main emissions from the composting process are carbon dioxide
and ammonia. Biogenic carbon dioxide emission from the process is not included in the
inventory due to its carbon neutral considerations (Chandel et al. 2012; Zhao et al. 2009). The
amount of ammonia produced during composting is estimated as per the method given in Pichtel
(2005). Aerobic composting of MSW is given by the following Eq. (1). The molecular formula
of MSW is calculated based on the physical composition of Bangalore waste and from the
method suggested in Tchobanoglos et al. (1993). The formula for MSW estimated is
29.40 43.93 16.64 1
. The formulae
a b c d
w x y z
in Eq. (1) represents the
composition of MSW and MBT waste respectively. The molecular formula of MBT waste was
found by performing CHN analysis and is of the form
15.86 2.26 13.35 1
 
 
2 2 3
C H O N 0.5 2 O C H O N
CO H O d nz NH
a b c d w x y z
ny s r c n
 
 
 
0.5 b nx 3(d nz)r  
s a nw
The organic content and moisture content MBT waste were obtained experimentally and
were found to be 53.56% and 51% respectively. The usage of compost substitutes/avoids the use
of chemical fertilizers and helps in preventing the possible impacts due to their production. The
avoided impact due to the substitution of fertilizers by compost is shown in Table 4.
Table 3. Environmental burdens resulting from the production 1 MJ of electricity (Indian
grid) and 1 L of diesel (GaBi -2014; Sharma et al., 2017)
Electricity (1MJ)
Diesel (1L)
GWP (kg CO2 eq)
AP (kg SO2 eq)
EP (kg PO3- eq)
HTP (1,4 DB eq*)
*1,4 Dichlorobenzene eq
Landfill emissions: Emissions from both the conventional and bioreactor landfills are
assumed to be similar in composition (Babu et al. 2014). Methane, carbon dioxide, oxides of
nitrogen and sulfur, hydrogen sulfide and VOCs are assumed to be the major components of
landfill emissions. The landfill gas produced by the disposal of MSW (0.969T) and MBT waste
(0.216T) in open dumps and landfills is calculated by using LandGEM model version 3.02.
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Table 4. Emissions resulting from the production of mineral fertilizer (GaBi, 2014).
N (kg)
P (kg)
K (kg)
GW; kg CO2
AP; kg SO2
Ep; kg of Phosphate
HTP (1,4-DB-eq)
Table 5. Emissions from Landfills
Table 6. Major parameters of leachate from open dumps and landfill in Bangalore
Open dumps, mg/L
Landfills/Bioreactor landfills, mg/L
The waste is assumed to be deposited for a one-year period and the gas generated in that one-
year duration is used for all emission and power generation calculations. The values of methane
generation rate (year-1) and the methane generation capacity (m3/Mg) used in LandGEM model
were 0.4 and 144 respectively. From Hong et al. 2010, the other gaseous emissions produced per
ton of waste are estimated and is shown in Table 5. The efficiency of the gas collection systems
in bioreactor landfill is assumed to be 90% (Barlaz et al. 2003). The power generated from
methane is calculated by assuming the calorific value of methane as 50 MJ/kg (Obersteiner et al.
2007). The emission factors for gas power plant used in bioreactor landfill is taken from MOE
Table 7. Characterization factors based on equivalency factors from IPCC 2001 GWP for
20 years and Eco-indicator 95
GWP; kg CO2
AP; kg SO2
EP; kg of
GWP=global warming potential; AP= acidification potential; EP=eutrophication potential; AEP=aquatic eco-
toxicity potential
Leachate emissions: A few major parameters of leachate representing the open dumps and
conventional landfills of Bangalore are given in Table 6. The amount of leachate generated is
assumed to be around 10% of precipitation for the landfill sites (Cabaraban et al. 2007) and for
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open dumps it was assumed to be in proportional to the rainfall. The 100 years average annual
precipitation of Bangalore is taken as 77.98 mm as per the data from Indian Meteorological
Department. Leachate collection efficiency in conventional landfill and bioreactor landfill is
assumed to be 80% (Abduli et al. 2011). The electricity consumption in the leachate treatment is
assumed as 0.2436 MJ per ton (Finnveden et al. 2005).
Table 8. Impact assessment results for scenarios (per functional unit)
Scenario 1
(Comp/Open dumps)
Scenario 2
Scenario 3
GWP; kg CO2 eq.
AP; kg SO2 eq.
EP; kg of Phosphate
HTP; 1,4-
Dichlorobenzene eq.
AEP; BOD, Ni, Zn
MRF=material recovery facility; Comp=composting; CLF=conventional landfill; BLF=bioreactor landfill
Five impact categories i.e., global warming, acidification, eutrophication, human toxicity and
aquatic ecotoxicity were investigated in this study. The impact categories were calculated by
multiplying the emissions accounted for in the inventory stage with an equivalency factor. The
various emissions contributing to different impact categories along with their characterization
factors that are considered in this study are given in Table 7.
The impact assessment results for the three scenarios are presented in Table 8. The global
warming potential of scenario 1 is greater than the other two cases. This is due to the direct
release of gaseous emissions from the open dumps. The recovery of methane and its utilization
for power generation reduces the GWP of scenario 3 considerably in comparison to scenario 2.
The acidification potential of scenario 2 and 3 are more than that of the open dumps. This is due
to the release of ammonia from the composting units of scenario 2 and 3 which are almost 32
times larger in size than that of the units in scenario 1. The eutrophication and aquatic
ecotoxicity potential are higher in open dumps in comparison to the conventional and bioreactor
landfills. This might be due to the contamination of untreated leachate with the water bodies. The
substitution of mineral fertilizers with compost results in considerable reduction in
eutrophication potential (by a factor of 4 and 8.37 in scenario 2 and 3 respectively). The human
toxicity potential of scenario 2 and 3 are higher than that of scenario 1 due to the indirect
emissions related to the utilization of electricity and fuel.
Among the alternatives considered, the integrated waste management system consisting of
MRF, composting and bioreactor landfills with leachate treatment and energy recovery option is
far more environmentally benign than the others. The study estimates that the aquatic ecotoxicity
potential of open dumps is considerably higher (a factor of 241) than the conventional or
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bioreactor landfills. The reports of leachate contaminating the ground and surface water sources
and its health impacts near the Mavallipura dump site (Lutringer, 2017) substantiates the above
finding. On the other hand, the study estimates that the by preferring bioreactor landfills over
open dumps, the GWP can be decreased by a factor of 48 in addition to the benefits of generating
power from LFG. Therefore, in case of Bangalore city, an integrated waste management system
consisting of bioreactor landfills with energy recovery would not only be an environmentally
benign, but also a sustainable and economically (Babu et al. 2014) viable option.
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The sustainable landfilling concept has several advantages over conventional waste management practices in addressing various socio-economic and environmental concerns. This study presents an overview of the sustainable landfilling concept and various unit processes associated with it. The waste management approaches followed in the city of Bangalore and the benefits of applying the sustainable landfilling concept are discussed. A review of the bioreactor landfills, landfill mining, and biocover systems are presented. Laboratory scale bioreactor studies on the degradation of mechanically and biologically treated waste of Bangalore city under anaerobic, aerobic, and semi-aerobic conditions are presented. The performance of bioreactor landfills and the selection of waste treatment units are greatly influenced by the municipal solid waste properties and hence are reviewed in the study.
Full-text available
The current practices of containing the waste in dumpsite/landfill are considered as unsustainable due to their negative impact on the environment, society and economy. Remediation of the existing open dumpsite into bioreactor landfills helps in recovering the valuable land area at a faster rate due to the reduction in the time required for waste stabilization process. The problem of leachate treatment can also be addressed effectively during the remediation process. Therefore, remediating an existing dumpsite can be classified as an approach towards achieving the sustainability in landfilling practices. In this study, an approach for remediating an existing municipal solid waste (MSW) dumpsite in Bangalore city is presented by addressing the three major aspects, viz., landfill gas (LFG), leachate and the recovery of air space. Modelling tools are used to estimate the LFG emission and to design the leachate collection and recirculation systems. The methane oxidation potential of the digested MBT waste as a biocover material is evaluated using column experiments. The biocover systems are then designed to mitigate the LFG emissions from the dumpsite.
Conference Paper
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Landfills are common land disposal methods employed in most of the developing countries across the world. The waste disposal methods, such as open dumps, landfill without and with gas recovery systems and bioreactor landfills, are assessed using the life-cycle analysis (LCA) method. These scenarios were applied to Bangalore (Karnataka, India). This method serves as a decision making tool for selecting the most sustainable, energy- and cost-efficient methods. The analysis is done in terms of the material flow, energy flow, and impacts of open dumping and land filling on the environment. The global warming potential was considered as the most important factor, as its impact on the environment is high. The life-cycle cost analysis (LCCA) is also done considering an average life of a landfill as 50 years. Cost analysis was done in terms of the initial fixed costs, yearly maintenance cost, and postclosure monitoring and maintenance cost. The revenue generated from trading power that could be generated from the landfills was also considered. The power that could be generated from the landfills was calculated as 11 MW. The bioreactor landfill could be used twice in 50 years when compared to the engineered landfill as the waste stabilization period varied from 10 years in bioreactor landfill to few decades in case of engineered landfills. Among the four scenarios, the bioreactor landfill had an edge over the other methods environmentally and economically, whereas the open dump scenario was the least favored option as the impacts caused to the environment was considerably huge.
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A review on comparison between recycling, composting and landfills is presented. In the life cycle assessment model, three scenarios with six alternative systems are studied. Each scenario included a landfill, both traditional and a bioreactor. Key defaults associated with the landfill process model include the waste density and the landfill gas collection efficiency.
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The management of municipal solid waste has become an acute problem due to enhanced economic activities and rapid urbanisation. Increased attention has been given by the government in recent years to handle this problem in a safe and hygienic manner. In this regard, Municipal Solid Waste Management (MSWM) environmental audit has been carried out for Bangalore city through the collection of secondary data from government agencies, and interviews with stakeholders and field surveys. Field surveys were carried out in seven wards (representative samples of the city) to understand the practice and identify the lacunae. The MSWM audit that was carried out functional-element-wise in selected wards to understand the efficacy and shortfalls, if any, is discussed in this paper. Biographical notes: Ramachandra holds a BE (Electrical Engg) from Bangalore University, India and a PhD in Energy and Environment from the Indian Institute of Science. He has made significant contributions in the area of energy and environment. His areas of research include energy systems, environmental management, regional planning, spatial decision support systems, GIS and remote sensing. He teaches principles of remote sensing, digital image processing, renewable energy technologies, and natural resources management. He has published over 108 research papers as well as nine books. His latest book entitled Management of Municipal Solid Waste, 2006, has been published by Capital Publishers, New Delhi. He is a fellow of the Institution of Engineers (India) and Institution of Electrical Engineers (UK), senior member, IEEE (USA) and AEE (USA), and many similar institutions.
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Potential environmental impacts associated with aerobic in-vessel composting and bioreactor landfilling were assessed using life cycle inventory (LCI) tool. LCI models for solid waste management (SWM) were also developed and used to compare environmental burdens of alternative SWM scenarios. Results from the LCI models showed that the estimated energy recovery from bioreactor landfilling was about 9.6megajoules (MJ) per kilogram (kg) of waste. Air emissions from in-vessel composting contributed to a global warming potential (GWP) of 0.86kg of CO2-equivalent per kg of waste, compared to 1.54kg of CO2-equivalent from bioreactor landfill. Waterborne emissions contributing to aquatic toxicity is less coming from in-vessel composting than from bioreactor landfilling. However, emissions to air and water that contribute to human toxicity are greater for the composting option than for the landfill option. Full costs for in-vessel composting is about 6 times greater than for the landfilling alternative. Integration of individually collected commingled recyclables, yard wastes, and residual wastes with windrow composting and bioreactor landfilling produces airborne and waterborne emissions with the least environmental effects among the alternatives considered. It also yields greater energy savings due to the conversion of the landfill gas (LFG) to electrical energy than the option that diverts yard waste, food waste and soiled paper for aerobic in-vessel composting. However, this scenario costs 68% more than that where the commingled collection of wastes is integrated with in-vessel composting and conventional landfilling, owing to increased collection costs.
Dumping of municipal solid waste into uncontrolled dumpsites is the most common method of waste disposal in most cities of India. These dumpsites are posing a serious challenge to environmental quality and sustainable development. Mumbai, which generates over 9000 t of municipal solid waste daily, also disposes of most of its waste in open dumps. It is important to analyse the impact of municipal solid waste disposal today and what would be the impact under integrated waste management schemes. In this study, life cycle assessment methodology was used to determine the impact of municipal solid waste management under different scenarios. Six different scenarios were developed as alternatives to the current practice of open dumping and partially bioreactor landfilling. The scenarios include landfill with biogas collection, incineration and different combinations of recycling, landfill, composting, anaerobic digestion and incineration. Global warming, acidification, eutrophication and human toxicity were assessed as environmental impact categories. The sensitivity analysis shows that if the recycling rate is increased from 10% to 90%, the environmental impacts as compared with present scenario would reduce from 998.43 kg CO2 eq t⁻¹ of municipal solid waste, 0.124 kg SO2 eq t⁻¹, 0.46 kg PO4⁻³ eq t⁻¹, 0.44 kg 1,4-DB eq t⁻¹ to 892.34 kg CO2 eq t⁻¹, 0.121 kg SO2 eq t⁻¹, 0.36 kg PO4⁻³ eq t⁻¹, 0.40 kg 1,4-DB eq t⁻¹, respectively. An integrated municipal solid waste management approach with a mix of recycling, composting, anaerobic digestion and landfill had the lowest overall environmental impact. The technologies, such as incineration, would reduce the global warming emission because of the highest avoided emissions, however, human toxicity would increase.
Background: The combustion of municipal solid waste (MSW) to generate heat or electricity (waste-to-energy [WTE]) could reduce net GHG emissions in the USA compared with combusting methane from landfills. Moreover, negative CO2 emissions could be achieved with CCS because 66% of the carbon in MSW is typically biogenic. Results and conclusion: For the five largest landfill sites in each state, we estimate that at least 58 and 11 sites have enough MSW to fuel WTE plants of >50 MWe and >100 MWe, respectively. Furthermore, half of these sites lie within 20 km of potential underground saline and other CO2 storage reservoirs. We estimate that the levelized electricity cost for WTE without CO2 capture is US$94/MWh and is $285/MWh with amine-based post-combustion capture technology. The cost of CO2 capture is $58/Mg CO2, resulting in a cost for carbon negative emissions of $93/Mg CO2; substantially lower than for some geoengineering methods, including capturing CO2 from air.
Conference Paper
Bangalore is among five largest cities of India producing about 3600 tons per day of municipal solid waste (MSW). MSW in Bangalore usually has a high percentage of fermentable organic components that degrade easily in nature. Presently, Bangalore employs a quasi-centralized collection system followed by an open-to-sky processing and land filling. A significant fraction also undergoes open dumping. Collection and transportation systems are today quite satisfactory; that does not allow anaesthetic accumulation of wastes in residential area or street corners. The informal sector for recycling is also quite active in collecting the recyclables from houses, open bins (wherever present), other collection /transportation systems as well as from dumping and processing sites. A few of the recyclers purchase recyclables from individual household, as is done in several parts of the country. The paper describes the potential for residential locality based recycling and processing systems involving total recovery and recycling of the recyclables and conversion of organic fermentables to biogas. In the past, a large number of such units have functioned achieving various levels of success – however none of them reported to be commercially viable. Most of such efforts did not sustain long periods and were often abandoned midway due to political and /or economic issues. In this paper we describe a locality based system and use its field data to show that commercially run processing systems can become viable. In order for this to happen, it is firstly necessary to achieve a high degree of non-organic waste recycling and in place of composting, the fermentable wastes are transformed to locally used biogas – this combination can alone be sustainable in today’s state of art in this area.
Life cycle assessment was performed to evaluate environmental impacts of two municipal solid waste (MSW) to energy schemes currently practiced in Thailand: incineration and anaerobic digestion. Potential impacts such as global warming, acidification, stratospheric ozone depletion, and photo-oxidant formation were avoided due to net electricity production and also fertilizer production as by-products from the anaerobic digestion scheme. In addition, the anaerobic digestion resulted in the higher net energy output compared to the incineration scheme. However, the incineration had less potential impact for nutrient enrichment. The LCA results were also useful in determining where the improvements could be made for both the schemes. In order to adopt a sustainable waste management system elsewhere in the country, decision makers may need to consider a combination of techniques, or an integrated method of management. LCA could serve as an invaluable tool for such an analysis.