Municipal Solid Waste Management Strategies Research Articles

PREDICTIve MODELS FOR MUNICIPAL SOLID WASTE (MSW) GENERATION AND COMPOSITION

To develop an effective municipal solid waste management strategy for a givencommunity, it is essential to know the amount of waste generated and the composition of',the waste stream at a given time and to identify a mechanism for reliable estimation offuture waste quantities and compositions. It has been shown in literature that the amountof waste generated in a country is proportional to its population and the mean livingstandards of the people or their income in addition to many other demographic factorsThis paper presents the findings of a study carried out in a suburban Municipal area inSri Lanka to develop a predictive model to estimate waste generation patterns at a giventime. Here, an attempt was made to analyse the quantity and composition of wastegeneration in a sample of households in the study area over a time period and relate thisto various demographic factors. Over 300 households were studied for this purpose.Through regression analysis the ,amount of waste and waste composition was related tothe demographic factors. It describes the basis for the sample selection, socio-economicparameters used for modeling and the methodology adopted for effective data collection.Stratified random sampling methodology based on Municipal wards and property valuewas used for the data collection. A technique that consider both the number ofhouseholds in a particular income group (property value range) and the standarddeviation of property values within a given income group was used to determine theappropriate sample sizes for each municipal ward.The per-capita waste generation and average composition of waste generated werederived by analysing descriptive statistics. Organic waste constitutes the largestcomponent of the generated waste in the area and regression analysis shows that the percapitageneration of organic waste per day in kg decreases as the number of persons perhousehold increases. It is also shown that the generation of organic and paper waste perhousehold very clearly increases with the increase in property value.

EXTENDED COST BENEFIT ANALYSIS OF A BIOGAS GENERATION PLANT

Solid waste is a growing problem in Sri Lanka in the absence of proper managementmeasures. Development and implementation of a National strategy for municipal solidwaste management is essential in order to reduce environmental, social and the economicproblems associated with the present disposal practices. Such strategies however, need tobe subjected to proper economic analysis in order to arrive at informed decisions. Thispaper presents an extended cost benefit analysis of a biogas generation plant that usesmunicipal solid waste as the raw material.To dispose vegetable market garbage available in Wattala, Kandana and Ja-ela areas a640 Mt capacity biogas/ bio fertilizer project has been housed at Muthurajawela (alongHamilton canal, Elakanda), by the National Engineering Research & DevelopmentCenter of Sri Lanka (NERDC) which uses Dry Batch Anaerobic Digester Technology.Among the other biological treatment options, anaerobic digestion is the most costeffective, due to the high-energy recovery linked to the process and its limitedenvironmental impacts.Economic analysis has been carried out to identify environmental costs and benefitsassociated with the above project. Several environmental valuation methods have beenapplied to value the identified costs and benefits. The main benefit of reduction ofmunicipal solid waste has been estimated by contingent valuation method using samplesfrom Wattala-Mabola, Ja-ela, and Peliyagoda local authority areas. Another benefit is thereduction of green house has emission due to the reduction of open dumping. Greenhouse gas (methane) emission from solid waste was estimated through Sholl Canionmodel and valued using avoided global damage cost approach. Benefits of biogas asenergy and organic fertilizers and employment benefits were estimated by market basedapproachesThe project is viable from economy and environment point of view with net present valueof Rs 142 million for a 20-year period with 10% discount rate. This analysis provides ajustification for undertaking solid waste management strategies in a technologically,environmentally and economically viable manner

Environmental impact and cost assessment of incineration and ethanol production as municipal solid waste management strategies

Purpose Municipal solid waste (MSW) can be handled with several traditional management strategies, including landfilling, incineration, and recycling. Ethanol production from MSW is a novel strategy that has been proposed and researched for practical use; however, MSW ethanol plants are not widely applied in practice. Thus, this study has been conducted to analyze and compare the environmental and economic performance of incineration and ethanol production as alternatives to landfilling MSW. Methods The ISO 14040 life cycle assessment framework is employed to conduct the environmental impact assessment of three different scenarios for the two MSW management strategies based on processing 1 ton of MSWas the functional unit. The first scenario models the process of incinerating MSW and recovering energy in the form of process heat; the second scenario also includes the process of incinerating MSW but yields in the recovery of energy in the form of electricity; and the third scenario models the process of converting MSW into ethanol. The economic impacts of each scenario are then assessed by performing benefit-to-cost ratio (BCR) and net present value (NPV) analyses. Results and discussion The results from the environmental impact assessment of each scenario reveal that scenario 2 has the highest benefits for resource availability while scenario 3 is shown to be the best alternative to avoid human health and ecosystems diversity impacts. Scenario 1 has the worst environmental performance with respect to each of these environmental endpoint indicators and has net environmental impacts. The results of the economic analysis indicate that the third scenario is the best option with respect to BCR and NPV, followed by scenarios 2 and 1, respectively. Furthermore, environmental and economic analysis results are shown to be sensitive to MSW composition. Conclusions It appears municipalities should prefer MSW incineration with electricity generation or MSW-to-ethanol conversion over MSW incineration with heat recovery as an alternative to landfilling. The contradiction between the environmental impact assessment results and economic analysisresultsdemonstratesthatthedecision-makingprocess

Compromising economic cost and air pollutant emissions of municipal solid waste management strategies by fuzzy multiobjective optimization model

Municipal solid waste management (MSWM) is an important environmental challenge and subject in urban planning. A sustainable MSWM strategy should consider not only economic efficiency but also life-cycle assessment of environmental impact. This study employs the fuzzy multiobjective linear programming (FMOLP) technique to find the optimal compromise between economic optimization and pollutant emission reduction for the MSWM strategy. Taichung City in Taiwan is evaluated as a case study. The results indicate that the optimal compromise MSWM strategy can reduce significant amounts of pollutant emissions and still achieve positive net profits. Minimization of the sulfur oxide (SOx) and nitrogen oxide (NOx) emissions are the two major priorities in achieving this optimal compromise strategy when recyclables recovery rate is lower; however, minimization of the carbon monoxide (CO) and particulate matter (PM) emissions become priority factors when recovery rate is higher. Implications: This paper applied the multiobjective optimization model to find the optimal compromise municipal solid waste management (MSWM) strategy, which minimizes both life-cycle operating cost and air pollutant emissions, and also to analyze the correlation between recyclables recovery rates and optimal compromise strategies. It is different from past studies, which only consider economic optimization or environmental impacts of the MSWM system. The result shows that optimal compromise MSWM strategy can achieve a net profit and reduce air pollution emission. In addition, scenario investigation of recyclables recovery rates indicates that resource recycling is beneficial for both economic optimization and air pollutant emission minimization.

Development and application of the decision support system for municipal solid waste management in central Taiwan

Municipal solid waste management (MSWM) is an important, practical and challenging environmental subject. The processes of a MSWM system include household collection, transportation, treatment, material recycling, compost and disposal. A regional program of MSWM is more complicated owing to the involvement of multi-municipality and multi-facility issues. Therefore, an effective decision support system capable of solving regional MSWM problems is necessary for decision-makers. This article employs linear programming techniques to establish a MSWM decision support system (MSWM-DSS) that is able to determine the least costs of regional MSWM strategies. The results of investigating a real-world case in central Taiwan indicate that a regional program is more economical and efficient. For the redeployment of MSW streams, the relatively least cost of operation for the MSWM system can still be achieved through the re-estimation of the MSWM-DSS. This tool and results are useful for MSWM policy-making in central Taiwan.

Daily Fluctuation in Solid Waste Generation in Rural Areas of Jammu (A Case Study In Parwah Village, Jammu

To plan a municipal solid waste management strategies for a given region, it is essential to know the quantity of waste generated. Past research have shown that amount of waste generated is proportional to the population and the average income of the people. This paper presents the findings of the study carried out in rural area at Parwah village of Block Marh, Jammu to determine solid waste generation rate on income bases. Average solid waste generation/ week, /month and per year of study area was calculated. Co-relation coefficient (r) between no. of individuals (human and animals) and solid waste generation /house/day in high, middle and low income households were also calculated and the results of the present study revealed that wealthier strata produces higher waste generation followed by low and middle income respectively. Overall compilation of the data of all the households of the study area reveal that the average solid waste generation in average household of the study area was observed to be 6561.543

Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes

In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of hypothetical scenarios, thus proving its adequacy for strategic planning.

An economic evaluation and assessment of environmental impact of the municipal solid waste management system for Taichung City in Taiwan

Municipal solid waste management (MSWM) is an important environmental challenge and subject in urban planning. For sustainable MSWM strategies, the critical management factors to be considered include not only economic efficiency of MSW treatment but also life-cycle assessment of the environmental impact. This paper employed linear programming technique to establish optimal MSWM strategies considering economic efficiency and the air pollutant emissions during the life cycle of a MSWM system, and investigated the correlations between the economical optimization and pollutant emissions. A case study based on real-world MSW operating parameters in Taichung City is also presented. The results showed that the costs, benefits, streams of MSW, and throughputs of incinerators and landfills will be affected if pollution emission reductions are implemented in the MSWM strategies. In addition, the quantity of particulate matter is the best pollutant indicator for the MSWM system performance of emission reduction. In particular, this model will assist the decision maker in drawing up a friendly MSWM strategy for Taichung City in Taiwan. Implications: Recently, life-cycle assessments of municipal solid waste management (MSWM) strategies have been given more considerations. However, what seems to be lacking is the consideration of economic factors and environmental impacts simultaneously. This work analyzed real-world data to establish optimal MSWM strategies considering economic efficiency and the air pollutant emissions during the life cycle of the MSWM system. The results indicated that the consideration of environmental impacts will affect the costs, benefits, streams of MSW, and throughputs of incinerators and landfills. This work is relevant to public discussion and may establish useful guidelines for the MSWM policies.

Integrated Modeling for Optimal Municipal Solid Waste Management Strategies under Uncertainty

In this study, an inexact fuzzy-probabilistic programming (IFPP) method is advanced for developing optimal municipal solid waste (MSW) management strategy with uncertain information. The IFPP can support the assessment of risk of violating constraints associated with fuzzy and random features. The developed method is applied to a case study of long-term MSW management planning in the city of Changchun, China. Violations for transfer-station capacity constraints are allowed under a range of probability and possibility levels, which are related to trade-offs between the system cost and the constraint-violation risk. The results indicate that useful solutions for planning the MSW management practices have been generated. They are valuable for supporting the identification of efficient waste-flow allocation patterns, the long-term capacity planning of the city’s waste management system, and the formulation of local policies regarding waste management under uncertainty.

Environmental assessment of alternative municipal solid waste management strategies. A Spanish case study

The aim of this study is to compare, from an environmental point of view, different alternatives for the management of municipal solid waste generated in the town of Castellón de la Plana (Spain). This town currently produces 207 ton of waste per day and the waste management system employed today involves the collection of paper/cardboard, glass and light packaging from materials banks and of rest waste at street-side containers. The proposed alternative scenarios were based on a combination of the following elements: selective collection targets to be accomplished by the year 2015 as specified in the Spanish National Waste Plan (assuming they are reached to an extent of 50% and 100%), different collection models implemented nationally, and diverse treatments of both the separated biodegradable fraction and the rest waste to be disposed of on landfills. This resulted in 24 scenarios, whose environmental behaviour was studied by applying the life cycle assessment methodology. In accordance with the ISO 14040-44 (2006) standard, an inventory model was developed for the following stages of the waste management life cycle: pre-collection (bags and containers), collection, transport, pre-treatment (waste separation) and treatment/disposal (recycling, composting, biogasification + composting, landfill with/without energy recovery). Environmental indicators were obtained for different impact categories, which made it possible to identify the key variables in the waste management system and the scenario that offers the best environmental behaviour. Finally, a sensitivity analysis was used to test some of the assumptions made in the initial life cycle inventory model.

MSW management strategies for the city of Rome: a comparative assessment

In this paper, on the basis of a detailed characterisation of the Municipal Solid Waste (MSW) generated in the city of Rome, different integrated management strategies regarding both source separation of selected fractions and the treatment and disposal of the residual commingled waste were compared and discussed in terms of achievable material and energy recovery. The main findings of this study, that can be extended to other regions characterised by similar environmental policies and social and economical conditions, showed that source separation percentages cannot realistically exceed certain maximum percentages, particularly when they are addressed at selecting waste fractions for recycling. Regarding the management of the residual commingled waste, thermal treatment of all the fractions for which no further material recovery can be realistically pursued resulted the most convenient strategy in terms of recoverable thermal energy.

Drivers in current and future municipal solid waste management systems: cases in Yokohama and Boston

Despite some progress, municipal solid waste (MSW) still poses pressure on cities and remains one of the major challenges in environmental management. There is no single solution to the problem since the drivers behind MSW systems may vary significantly from city to city. In this context, the development of a common strategy to attain a sustainable management has been increasingly difficult. This paper presents an issue-driven analytical framework to evaluate the past, present and future MSW management strategy for the cities of Yokohama and Boston considering four driver categories while evaluating if the relevance of these drivers has changed over time. These categories represent: (i) legal drivers (e.g. laws and regulations); (ii) technology development and institutional drivers (e.g. available technologies); (iii) regional and international drivers (e.g. solid waste flow as recyclable resources); and (iv) socio-economic drivers (e.g. population trends and public awareness). The analysis indicated that solid waste management capacity for both cases was under stress due to different reasons. In the case of Boston, the moratorium for disposal facilities played an important role while increasing population was a key driver for the city of Yokohama. The future management scenario suggests that various waste-to-energy alternatives and strong solid waste reduction policies will play a key role for Boston. In Yokohama, a shift on waste composition and generation triggered by a demographic change may open the path for new technologies while also considering the international demand of solid waste as a recyclable resource.

Quantifying system uncertainty of life cycle assessment based on Monte Carlo simulation

Many studies evaluate the results of applying different life cycle impact assessment (LCIA) methods to the same life cycle inventory (LCI) data and demonstrate that the assessment results would be different with different LICA methods used. Although the importance of uncertainty is recognized, most studies focus on individual stages of LCA, such as LCI and normalization and weighting stages of LCIA. However, an important question has not been answered in previous studies: Which part of the LCA processes will lead to the primary uncertainty? The understanding of the uncertainty contributions of each of the LCA components will facilitate the improvement of the credibility of LCA. A methodology is proposed to systematically analyze the uncertainties involved in the entire procedure of LCA. The Monte Carlo simulation is used to analyze the uncertainties associated with LCI, LCIA, and the normalization and weighting processes. Five LCIA methods are considered in this study, i.e., Eco-indicator 99, EDIP, EPS, IMPACT 2002+, and LIME. The uncertainty of the environmental performance for individual impact categories (e.g., global warming, ecotoxicity, acidification, eutrophication, photochemical smog, human health) is also calculated and compared. The LCA of municipal solid waste management strategies in Taiwan is used as a case study to illustrate the proposed methodology. The primary uncertainty source in the case study is the LCI stage under a given LCIA method. In comparison with various LCIA methods, EDIP has the highest uncertainty and Eco-indicator 99 the lowest uncertainty. Setting aside the uncertainty caused by LCI, the weighting step has higher uncertainty than the normalization step when Eco-indicator 99 is used. Comparing the uncertainty of various impact categories, the lowest is global warming, followed by eutrophication. Ecotoxicity, human health, and photochemical smog have higher uncertainty. In this case study of municipal waste management, it is confirmed that different LCIA methods would generate different assessment results. In other words, selection of LCIA methods is an important source of uncertainty. In this study, the impacts of human health, ecotoxicity, and photochemical smog can vary a lot when the uncertainties of LCI and LCIA procedures are considered. For the purpose of reducing the errors of impact estimation because of geographic differences, it is important to determine whether and which modifications of assessment of impact categories based on local conditions are necessary. This study develops a methodology of systematically evaluating the uncertainties involved in the entire LCA procedure to identify the contributions of different assessment stages to the overall uncertainty. Which modifications of the assessment of impact categories are needed can be determined based on the comparison of uncertainty of impact categories. Such an assessment of the system uncertainty of LCA will facilitate the improvement of LCA. If the main source of uncertainty is the LCI stage, the researchers should focus on the data quality of the LCI data. If the primary source of uncertainty is the LCIA stage, direct application of LCIA to non-LCIA software developing nations should be avoided.

Modelling greenhouse gas emissions for municipal solid waste management strategies in Ottawa, Ontario, Canada

Human-induced climate change, through the emission of greenhouse gases, may result in a significant negative impact on Earth. Canada is one of the largest per capita emitters of greenhouse gas, generating 720 megatonnes (Mt) carbon dioxide equivalents (CO 2e), or per capita emissions of 23.2 t CO 2e. The solid waste sector in Canada was directly responsible for 25 Mt CO 2e in 2001, of which 23 Mt CO 2e were produced by landfill gas (LFG). A modelling exercise was undertaken to determine greenhouse gas (GHG) emissions from the waste sector using the waste disposal, recycling, and composting data from Ottawa, Ontario, Canada for the year 2003, as well as the results of an audit of residential units performed in the same year. This evaluation determined that, among the options examined, waste incineration, further source separation of recyclables, and anaerobic digestion of an organic wastes have the greatest benefits for reducing GHG emissions in the City of Ottawa's waste sector. Challenges surrounding the installation of incineration facilities in Canada suggest that improved diversion of recyclable materials and anaerobic digestion of organic materials are the optimal options for the City of Ottawa to pursue.

Municipal solid waste management strategies in Turkey

Municipal solid waste (MSW) is a major environmental problem in Turkey, as in many developing countries. Problems associated with municipal solid waste are difficult to address, but efforts towards more efficient collection and transportation and environmentally acceptable waste disposal continue in Turkey. Although strict regulations on the management of solid waste are in place, primitive disposal methods such as open dumping and discharge into surface water have been used in various parts of Turkey. This study presents a brief history of the legislative trends in Turkey for MSW management. The study also presents the MSW responsibility and management structure together with the present situation of generation, composition, recycling, and treatment. The results show that approximately 25 million ton of MSW are generated annually in Turkey. About 77% of the population receives MSW services. In spite of efforts to change open dumping areas into sanitary landfills and to build modern recycling and composting facilities, Turkey still has over 2000 open dumps.

Factors Influencing Regional Municipal Solid Waste Management Strategies

Although regionalization policies have been proven as good strategies for municipal solid waste (MSW) management in previous studies, the optimal allocation of the waste stream is significantly affected by several influential factors, thus further investigation of the impacts of these factors on regional MSW management strategies is necessary. This study demonstrated the impacts of waste-to-electricity transformation coefficient (WETC) of incinerators and the fluctuation of unit tipping fees on the regional MSW flow/allocation of the Taipei metropolitan area from practical and economic perspectives. Real-world data and linear programming were used to obtain the least-cost alternatives under different scenarios. Analytical results indicated some treatment facilities had geographic superiority and their priorities changed when actual WETCs of incinerators were considered. Treatment facilities located at weighted centers were identified. The allocation of MSW among incinerators and landfills is affected by fluctuation of unit tipping fees within a certain range. Treatment facilities sensitive to the changes in unit tipping fees were also identified. Regression equations were also established that can estimate the cost items of MSW management scenarios with different unit tipping fees. The results of this study are very useful for daily basis regulation of MSW administration.

Life cycle assessment of solid waste management options for Eskisehir, Turkey

Life cycle assessment (LCA) methodology was used to determine the optimum municipal solid waste (MSW) management strategy for Eskisehir city. Eskisehir is one of the developing cities of Turkey where a total of approximately 750tons/day of waste is generated. An effective MSW management system is needed in this city since the generated MSW is dumped in an unregulated dumping site that has no liner, no biogas capture, etc. Therefore, five different scenarios were developed as alternatives to the current waste management system. Collection and transportation of waste, a material recovery facility (MRF), recycling, composting, incineration and landfilling processes were considered in these scenarios. SimaPro7 libraries were used to obtain background data for the life cycle inventory. One ton of municipal solid waste of Eskisehir was selected as the functional unit. The alternative scenarios were compared through the CML 2000 method and these comparisons were carried out from the abiotic depletion, global warming, human toxicity, acidification, eutrophication and photochemical ozone depletion points of view. According to the comparisons and sensitivity analysis, composting scenario, S3, is the more environmentally preferable alternative. In this study waste management alternatives were investigated only on an environmental point of view. For that reason, it might be supported with other decision-making tools that consider the economic and social effects of solid waste management.

Municipal solid waste characterizations and management strategies for the Lower Rio Grande Valley, Texas

The Lower Rio Grande Valley (LRGV or Valley) in Texas, facing the big waste management challenge along the US-Mexico border today, is at the crossroads as a result of the rapid population growth, the scarcity of landfill space, the bi-nation's trade impacts, and the illusive goal of environmental sustainability. This paper offers a unique municipal solid waste investigation with regard to both physical and chemical characteristics leading to illuminate the necessary management policies with greater regional relevancy. With multiple sampling campaigns conducted during the spring of 2005, this study holistically summarizes the composition of solid waste, the statistical distribution patterns of key recyclable items, and the heating value in an uncertain environment. Research findings indicate that high fractions of plastics and paper in the waste stream imply a strong potential for energy recovery. Incineration options are thus bolstered by mildly high heating values across 10 cities in this region, which may lead to save land resources required for final disposal and increase electricity generation in the long run. Additional regression analyses further identify the correlation between recyclable items and heating value, which show that current recycling programs permit no obvious negative impacts on the incineration option. Final statistical hypothesis tests for both the Brownsville-Harlingen-San Benito and the McAllen-Edinburg-Mission metropolitan regions help foster consistent management strategies across the Valley regardless of the trivial differences of waste characteristics in between.

AIR DISPERSION MODELING OF VOCs EMITTED FROM MSW LANDFILLS

In Turkey, landfilling is the most preferred method of municipal solid waste management strategy since it is still considered to be the most cost-effective method of waste disposal. Landfills are very complex systems in which various interactive processes proceed simultaneously. Following waste deposition, a landfill gas mainly comprised of methane and carbon dioxide is generated due to the microbial decomposition. Various trace volatile organic compounds (VOCs) besides main components of landfill gas are also produced. The main components and the trace gases from landfills contribute to the greenhouse effect and influence the ozone layer. In addition, adverse effects of landfill gas on human health and vegetation as well as complaints due to unpleasant odor at landfills have been also reported in the literature. Particularly, during landfill operations and after landfill closure, VOCs emitted from landfills should be determined and evaluated due to their probable carcinogenicity. In this study, the dispersion of VOCs emitted at the IZAYDAS landfill (Kocaeli, Turkey) was modeled. The landfill has been in use since 1998, and covers an area of 363,000 m2 with a total capacity of 3,163,000 m3. First, USEPA`s Landfill Gas Emissions Model (LandGEM V3.2) was used to determine the concentrations of the VOCs emitted from the landfill. Then, USEPA s ISCST3 model (ISC-AERMOD V5.3) was employed for the air dispersion modeling. Following the model inputs such as meteorological parameters, VOC concentrations, digital maps, etc., the wind rose for a five year (2000 2004) period and the concentration gradients were obtained.

Municipal solid waste management strategies and technologies for sustainable solutions

From the contents: Introduction * Waste Disposal: What are the impacts * Recycling, Thermal Treatment and Recovery * Biological and Bio-Mechanical Processes * Advanced Thermal Treatment Processes * Ecology: Which Technologies Perform Best * Assessing and Improving Social Compatibility * Towards Sustainable Waste Management * Concluding Remarks.