GIS-based approach for optimized siting of municipal solid waste landfill

The exponential rise in the urban population of the developing countries in the past few decades and the resulting accelerated urbanization phenomenon has brought to the fore the necessity to develop environmentally sustainable and efficient waste management systems. Sanitary landfill constitutes one of the primary methods of municipal solid waste disposal. Optimized siting decisions have gained considerable importance in order to ensure minimum damage to the various environmental sub-components as well as reduce the stigma associated with the residents living in its vicinity, thereby enhancing the overall sustainability associated with the life cycle of a landfill. This paper addresses the siting of a new landfill using a multi-criteria decision analysis (MCDA) and overlay analysis using a geographic information system (GIS). The proposed system can accommodate new information on the landfill site selection by updating its knowledge base. Several factors are considered in the siting process including geology, water supply resources, land use, sensitive sites, air quality and groundwater quality. Weightings were assigned to each criterion depending upon their relative importance and ratings in accordance with the relative magnitude of impact. The results from testing the system using different sites show the effectiveness of the system in the selection process.     

Investigating municipal solid waste generation and management in Ilorin for possible integrated waste-management system

Journal of Material Cycles and Waste Management - The municipal solid waste generated in Ilorin is so enormous that the management method available cannot sufficiently cater for it. This is evident...     

A multi-echelon supply chain model for municipal solid waste management system

In this paper, a multi-echelon multi-period solid waste management system (MSWM) was developed by inoculating with multi-echelon supply chain. Waste managers, suppliers, industries and distributors could be engaged in joint strategic planning and operational execution. The principal of MSWM system is interactive planning of transportation and inventory for each organization in waste collection, delivery and disposal. An efficient inventory management plan for MSWM would lead to optimized productivity levels under available capacities (e.g., transportation and operational capacities). The applicability of the proposed system was illustrated by a case with three cities, one distribution and two waste disposal facilities. Solutions of the decision variable values under different significant levels indicate a consistent trend. With an increased significant level, the total generated waste would be decreased, and the total transported waste through distribution center to waste to energy and landfill would be decreased as well.     

Forecasting municipal solid waste generation in a fast-growing urban region with system dynamics modeling

Both planning and design of municipal solid waste management systems require accurate prediction of solid waste generation. Yet achieving the anticipated prediction accuracy with regard to the generation trends facing many fast-growing regions is quite challenging. The lack of complete historical records of solid waste quantity and quality due to insufficient budget and unavailable management capacity has resulted in a situation that makes the long-term system planning and/or short-term expansion programs intangible. To effectively handle these problems based on limited data samples, a new analytical approach capable of addressing socioeconomic and environmental situations must be developed and applied for fulfilling the prediction analysis of solid waste generation with reasonable accuracy. This study presents a new approach--system dynamics modeling--for the prediction of solid waste generation in a fast-growing urban area based on a set of limited samples. To address the impact on sustainable development city wide, the practical implementation was assessed by a case study in the city of San Antonio, Texas (USA). This area is becoming one of the fastest-growing regions in North America due to the economic impact of the North American Free Trade Agreement (NAFTA). The analysis presents various trends of solid waste generation associated with five different solid waste generation models using a system dynamics simulation tool--Stella. Research findings clearly indicate that such a new forecasting approach may cover a variety of possible causative models and track inevitable uncertainties down when traditional statistical least-squares regression methods are unable to handle such issues.     

Leachate generation and biogas energy recovery in the Jebel Chakir municipal solid waste landfill,Tunisia

A survey was conducted between 2006 and 2008 in order to identify municipal solid waste (MSW) composition and its influence on leachate generation and to assess the amount of biogas yield from the Jebel Chakir landfill in Tunis City. The organic fraction was the predominant compound in the MSW, followed by paper, fine, plastic, leather, rubber, metal, textile, glass and ceramic. The average MSW moisture content varies from 60 % in the wet season to 80 % in the dry one. The recognised MSW composition is well representative if compared to that of cities in developing countries. A large leachate quantity is produced in the landfill of Jebel Chakir, despite the negative water balance of the site. Based on the annual MSW landfilled quantities and using the LandGEM model, the expected peak landfill gas (LFG) production is estimated to occur 1 year after the landfill closure with a rate of 3.53 × 10⁷ m³/year. The analysis of the potential conversion of LFG to electric energy shows it at a total LFG-to-electricity energy of around 257 GWh with a heating value of 4,475 kcal/m³ based on an LFG collection efficiency of 33 % and energy efficiency of 33 % giving an economic feasibility for a 10 MW power plant.     

A hybrid method for quasi-three-dimensional slope stability analysis in a municipal solid waste landfill

Limited space for accommodating the ever increasing mounds of municipal solid waste (MSW) demands the capacity of MSW landfill be maximized by building landfills to greater heights with steeper slopes. This situation has raised concerns regarding the stability of high MSW landfills. A hybrid method for quasi-three-dimensional slope stability analysis based on the finite element stress analysis was applied in a case study at a MSW landfill in north-east Spain. Potential slides can be assumed to be located within the waste mass due to the lack of weak foundation soils and geosynthetic membranes at the landfill base. The only triggering factor of deep-seated slope failure is the higher leachate level and the relatively high and steep slope in the front. The valley-shaped geometry and layered construction procedure at the site make three-dimensional slope stability analyses necessary for this landfill. In the finite element stress analysis, variations of leachate level during construction and continuous settlement of the landfill were taken into account. The "equivalent" three-dimensional factor of safety (FoS) was computed from the individual result of the two-dimensional analysis for a series of evenly spaced cross sections within the potential sliding body. Results indicate that the hybrid method for quasi-three-dimensional slope stability analysis adopted in this paper is capable of locating roughly the spatial position of the potential sliding mass. This easy to manipulate method can serve as an engineering tool in the preliminary estimate of the FoS as well as the approximate position and extent of the potential sliding mass. The result that FoS obtained from three-dimensional analysis increases as much as 50% compared to that from two-dimensional analysis implies the significance of the three-dimensional effect for this study-case. Influences of shear parameters, time elapse after landfill closure, leachate level as well as unit weight of waste on FoS were also investigated in this paper. These sensitivity analyses serve as the guidelines of construction practices and operating procedures for the MSW landfill under study.     

A novel sustainable decision making model for municipal solid waste management

This paper reviews several models developed to support decision making in municipal solid waste management (MSWM). The concepts underlying sustainable MSWM models can be divided into two categories: one incorporates social factors into decision making methods, and the other includes public participation in the decision-making process. The public is only apprised or takes part in discussion, and has little effect on decision making in most research efforts. Few studies have considered public participation in the decision-making process, and the methods have sought to strike a compromise between concerned criteria, not between stakeholders. However, the source of the conflict arises from the stakeholders' complex web of value. Such conflict affects the feasibility of implementing any decision. The purpose of this study is to develop a sustainable decision making model for MSWM to overcome these shortcomings. The proposed model combines multicriteria decision making (MCDM) and a consensus analysis model (CAM). The CAM is built up to aid in decision-making when MCDM methods are utilized and, subsequently, a novel sustainable decision making model for MSWM is developed. The main feature of CAM is the assessment of the degree of consensus between stakeholders for particular alternatives. A case study for food waste management in Taiwan is presented to demonstrate the practicality of this model.     

Perspectives for integrated municipal solid waste management in Thessaloniki, Greece

Local authorities need updated and reliable data on the quantity and the quality of the waste generated in their area, in order to establish an integrated solid waste management system capable of fulfilling regional and national waste management targets. This paper presents information about the quantity and the characteristics of the municipal solid waste generated in Thessaloniki, which is the second largest city in Greece. It is based on the results of three research programs investigating the evolution of municipal solid waste. The investigations were carried out over the last 20 years at the landfill of Thessaloniki by the same research group using statistically acceptable practices for sampling and hand sorting. The results show a great increase in the incoming quantities during the last years and a significant increase of the per capita generation. There is also a significant change in the composition, demonstrated mainly by a decrease in the organic fraction followed by an increase of packaging materials (paper and plastic).     

Flow analysis of metals in a municipal solid waste management system

This study aimed to identify the metal flow in a municipal solid waste (MSW) management system. Outputs of a resource recovery facility, refuse derived fuel (RDF) production facility, carbonization facility, plastics liquefaction facility, composting facility, and bio-gasification facility were analyzed for metal content and leaching concentration. In terms of metal content, bulky and incombustible waste had the highest values. Char from a carbonization facility, which treats household waste, had a higher metal content than MSW incinerator bottom ash. A leaching test revealed that Cd and Pb in char and Pb in RDF production residue exceeded the Japanese regulatory criteria for landfilling, so special attention should be paid to final disposal of these substances. By multiplying metal content and the generation rate of outputs, the metal content of input waste to each facility was estimated. For most metals except Cr, the total contribution ratio of paper/textile/plastics, bulky waste, and incombustible waste was over 80%. Approximately 30% of Cr originated from plastic packaging. Finally, several MSW management scenarios showed that most metals are transferred to landfills and the leaching potential of metals to the environment is quite small.     

Investigation of integrated municipal solid waste management strategies for Oman: an assessment of waste diversion,electricity generation and greenhouse-gas emissions

Journal of Material Cycles and Waste Management - The need of an integrated municipal solid waste (MSW) management system to maximize resource recovery and simultaneously reduce greenhouse-gas...     

Development of a purpose built landfill system for the control of methane emissions from municipal solid waste

In the present paper, a new system of purpose built landfill (PBLF) has been proposed for the control of methane emissions from municipal solid waste (MSW), by considering all favourable conditions for improved methane generation in tropical climates. Based on certain theoretical considerations multivariate functional models (MFMs) are developed to estimate methane mitigation and energy generating potential of the proposed system. Comparison was made between the existing waste management system and proposed PBLF system. It has been found that the proposed methodology not only controlled methane emissions to the atmosphere but also could yield considerable energy in terms of landfill gas (LFG). Economic feasibility of the proposed system has been tested by comparing unit cost of waste disposal in conventional as well as PBLF systems. In a case study of MSW management in Mumbai (INDIA), it was found that the unit cost of waste disposal with PBLF system is seven times lesser than that of the conventional waste management system. The proposed system showed promising energy generation potential with production of methane worth of Rs. 244 millions/y ($5.2 million/y). Thus, the new waste management methodology could give an adaptable solution for the conflict between development, environmental degradation and natural resources depletion.     

A multi-objective approach to solid waste management

The issue addressed in this paper consists in the localization and dimensioning of transfer stations, which constitute a necessary intermediate level in the logistic chain of the solid waste stream, from municipalities to the incinerator. Contextually, the determination of the number and type of vehicles involved is carried out in an integrated optimization approach. The model considers both initial investment and operative costs related to transportation and transfer stations. Two conflicting objectives are evaluated, the minimization of total cost and the minimization of environmental impact, measured by pollution. The design of the integrated waste management system is hence approached in a multi-objective optimization framework. To determine the best means of compromise, goal programming, weighted sum and fuzzy multi-objective techniques have been employed. The proposed analysis highlights how different attitudes of the decision maker towards the logic and structure of the problem result in the employment of different methodologies and the obtaining of different results. The novel aspect of the paper lies in the proposal of an effective decision support system for operative waste management, rather than a further contribution to the transportation problem. The model was applied to the waste management of optimal territorial ambit (OTA) of Palermo (Italy).     

A GIS-based system for allocating municipal solid waste incinerator compensatory fund

To ease the NIMBY (not in my back yard) syndrome of constructing municipal solid waste (MSW) incinerators in Taiwan, compensatory funding is widely allocated to the impacted communities to gain the acceptance and support of residents living the impacted areas. This paper presents a spatial methodology for distributing a compensatory fund more logically based on the environmental impact on each neighborhood in Taipei City. This method integrates ten impact factors, which have been proposed by a local committee, to evaluate all neighborhoods using mathematical models combined with spatial analyses in an analytic hierarchy process. The compensatory fund is distributed according to the resulting final scores. A GIS (geographic information systems)-based system has been developed to assist in assigning the final scores to the neighborhoods impacted. Results on impact factors and fund distributions are combined; they are included in an information system and displayed in spatial scales. For Taipei City, the impact of air quality during the incinerator operating period is the item of greatest concern to the surrounding residents and thus, it receives a relatively higher weight of 0.2894. As a result, high impact scores were assigned to not only those neighborhoods hosting the incinerators, but also the neighborhoods where the maximum particulate air pollutants occurred. This approach could be applicable to other MSW incinerators with similar environmental impact problems and interest in compensation schemes.     

A comparison of municipal solid waste management in Berlin and Singapore

A comparative analysis of municipal solid waste management (MSWM) in Singapore and Berlin was carried out in order to identify its current status, and highlight the prevailing conditions of MSWM. An overview of the various aspects of MSWM in these two cities is provided, with emphasis on comparing the legal, technical, and managerial aspects of MSW. Collection systems and recycling practiced with respect to the involvement of the government and the private sector, are also presented.Over last two decades, the city of Berlin has made impressive progress with respect to its waste management. The amounts of waste have declined significantly, and at the same time the proportion that could be recovered and recycled has increased. In contrast, although Singapore’s recycling rate has been increasing over the past few years, rapid economic and population growth as well as change in consumption patterns in this city-state has caused waste generation to continue to increase. Landfilling of MSW plays minor role in both cities, one due to geography (Singapore) and the other due to legislative prohibition (Berlin). Consequently, both in Singapore and Berlin, waste is increasingly being used as a valuable resource and great efforts have been made for the development of incineration technology and energy recovery, as well as climate protection.     

Feasibility of energy recovery from municipal solid waste in an integrated municipal energy supply and waste management system.

A decision-support model for determining the feasibility of a planned energy-from-waste (EfW) investment for an integrated waste management and energy supply system is presented. The aim is to present an easy-to-understand, inexpensive and fast-to-use tool to decision-makers for modelling and evaluating different kinds of processes. Special emphasis is put on forming the model and interpretation of the results of the example case. The simple integrated system management (SISMan) model is presented through a practical example of the use of the model. In the example the viability of the described system is studied by comparing five different cases including different waste-derived fuels (WDF), non-segregated municipal solid waste (MSW) being one of the fuel options. The nominal power output of the EfW plant varied in each case according to the WDF classification. The numeric values for two main variables for each WDF type were determined, the WDF price at the gate of the EfW plant and the waste management fee (WMF) according to the 'polluter pays' -principle. Comparison between the five cases was carried out according to two determinants, the WMF related to each case and the recovery rate related to each case. The numeric values for the constants and variables used in the calculations were chosen as realistically as possible using available data related to the issue. In the example of this paper, the mass-incineration solution ('pure' MSW as a fuel) was found to be the most viable solution for the described system according to the calculations. However, the final decision of the decision-makers might differ from this in the real world due to extra 'fuzzy' information that cannot be reliably included in the calculations. This paper shows that certain key values of modelled systems can be calculated using an easy-to-use tool at the very early stages of a larger design process involving municipal and business partners. The use of this kind of tools could significantly decrease the overall design costs of large systems in the long run by cutting out irrational system options at the very beginning of the planning.     

Alternative approaches for better municipal solid waste management in Mumbai, India

Waste is an unavoidable by product of human activities. Economic development, urbanization and improving living standards in cities, have led to an increase in the quantity and complexity of generated waste. Rapid growth of population and industrialization degrades the urban environment and places serious stress on natural resources, which undermines equitable and sustainable development. Inefficient management and disposal of solid waste is an obvious cause of degradation of the environment in most cities of the developing world. Municipal corporations of the developing countries are not able to handle increasing quantities of waste, which results in uncollected waste on roads and in other public places. There is a need to work towards a sustainable waste management system, which requires environmental, institutional, financial, economic and social sustainability. This study explores alternative approaches to municipal solid waste (MSW) management and estimates the cost of waste management in Mumbai, India. Two alternatives considered in the paper are community participation and public private partnership in waste management. Data for the present study are from various non-governmental organizations (NGOs) and from the private sector involved in waste management in Mumbai. Mathematical models are used to estimate the cost per ton of waste management for both of the alternatives, which are compared with the cost of waste management by Municipal Corporation of Greater Mumbai (MCGM). It is found that the cost per ton of waste management is Rs. 1518 (35 US dollars) with community participation; Rs. 1797 (41 US dollars) with public private partnership (PPP); and Rs. 1908 (44 US dollars) when only MCGM handles the waste. Hence, community participation in waste management is the least cost option and there is a strong case for comprehensively involving community participation in waste management.     

GIS-based modelling for the estimation of municipal solid waste generation and collection

In the present paper, an innovative model for the estimation of municipal solid waste generation and collection is proposed. This model is part of an extended solid waste management system and uses a spatial Geodatabase, integrated in a GIS environment. It takes into consideration several parameters of waste generation, such as population density, commercial activities, road characteristics and their influence on the location and allocation of waste bins. Ground-based analysis was applied for the estimation of the inter-relations between the aforementioned factors and the variations in waste generation between residential and commercial areas. Therefore, the proposed model follows a unified categorization approach for residential and commercial activities and focuses on the dominant factors that determine waste generation in the area under study. The most important result of the research work presented in the current paper is an accurate estimation of the optimal number of waste bins and their allocation. A new methodology and an appropriate algorithm have been developed for this purpose in order to facilitate routing and waste collection. By using these results, municipalities aware of social, economical and environmental factors, related to waste management, can achieve optimal usage of their resources and offer the best possible services to their citizens.     

Effect of leachate recirculation on the migration of copper and zinc in municipal solid waste and municipal solid waste incineration bottom ash co-disposed landfill

Municipal solid waste incinerator (MSWI) bottom ash was allowed to be disposed of with municipal solid waste (MSW) in landfill sites in the recently enacted standard of China. In this study, three sets of simulated landfill reactors, namely, conventional MSW landfill (CL), conventional MSWI bottom ash and MSW co-disposed landfill (CCL), and leachate recirculated MSWI bottom ash and MSW co-disposed landfill (RCL), were operated to investigate the environmental impact of the co-disposal. The effect of leachate recirculation on the migration of Cu and Zn in the co-disposed landfill was also presented. The results showed that the co-disposal of MSWI bottom ash with MSW would not enhance the leaching of Cu and Zn from landfill. However, the co-disposal increased the Cu and Zn contents of the refuse in the bottom layer of the landfill from 56.7 to 65.3 mg/kg and from 210 to 236 mg/kg, respectively. The recirculation of the leachate could further increase the Cu and Zn contents of the refuse in the bottom layer of the landfill to 72.9 and 441 mg/kg, respectively. Besides these observations, the results also showed that the co-disposed landfill with leachate recirculation could facilitate the stabilization of the landfill.     

The municipal solid waste system and solid waste characterization at the municipality of Veles, Macedonia

A short-term study to characterize the solid waste stream in the Municipality of Veles, Macedonia, was performed during a 1 week period in the summer of 2002. In this study, several important parameters of the municipal solid waste stream were assessed. It was estimated that the average daily generation rate is 1.06+/-0.56 kg/cap/day, while the specific weights of the uncompacted and compacted solid waste are approximately 140.5 kg/m3 and 223 kg/m3, respectively. Furthermore, it was estimated that the daily generated volume of uncompacted waste is 7.5+/-4 L/cap/day. Although the short-term study is characterized by numerous limitations, in the absence of other existing data, such a study with direct measurements could significantly contribute to the development of an efficient solid waste management system in countries with economies in transition like Macedonia.