Does municipal solid waste composting make economic sense?

Currently there is widespread interest on the part of local Governments in incorporating municipal solid waste (MSW) composting into their integrated solid waste management systems. However, there is little information on the costs of MSW composting and how those costs compare with the costs of alternative forms of waste disposal (especially traditional land disposal). This article begins to fill this information gap by reporting the results of a survey of 19 MSW composting facilities around the United States. Results indicate that MSW composting generally costs around $50 per ton, and that very few facilities receive any revenues from the sale of compost to offset operating costs. Additional economic analysis indicates that, at present, MSW composting cannot be justified on financial grounds in most parts of the US, but may be competitive with land disposal where the cost of landfilling is high (such as the north-east).1998 Academic Press     

垃圾填埋处理中微量金属元素迁移和转变特性分析

城市生活垃圾中含有多种微量金属元素,并且在填埋处理过程中会产生重金属的二次污染,是城市垃圾填埋处理中最难解决的问题。本文对垃圾中微量金属的来源、微量金属在填埋过程中的迁移和转变特性等方面进行了研究。研究认为,微量金属在填埋处理过程中除受本身特性的影响,还与垃圾的产地和组成有关。     

粪渣污泥上清液和填埋场渗滤液混合处理工程分析

针对深圳市的情况,提出将粪渣污泥脱水上清液和玉龙坑垃圾填埋场渗滤液进行混合处理的工程方案。经过比较,推荐上清液和渗滤液混合废水的处理采用ＵＡＳＢ和好氧生物处理工艺,脱水粪渣和剩余污泥的处理则采用高温好氧堆肥的方案,使排放出水达到排放标准的要求下,做到了污泥的资源化利用,工程和运行管理方面也是可行的。     

Techno-economic analysis and environmental impact assessment of energy recovery from Municipal Solid Waste (MSW) in Brazil

Due to the lack of appropriate policies in the last decades, 60% of Brazilian cities still dump their waste in non-regulated landfills (the remaining ones dump their trash in regulated landfills), which represent a serious environmental and social problem. The key objective of this study is to compare, from a techno-economic and environmental point of view, different alternatives to the energy recovery from the Municipal Solid Waste (MSW) generated in Brazilian cities. The environmental analysis was carried out using current data collected in Betim, a 450,000 inhabitants city that currently produces 200 tonnes of MSW/day. Four scenarios were designed, whose environmental behaviour were studied applying the Life Cycle Assessment (LCA) methodology, in accordance with the ISO 14040 and ISO 14044 standards. The results show the landfill systems as the worst waste management option and that a significant environmental savings is achieved when a wasted energy recovery is done. The best option, which presented the best performance based on considered indicators, is the direct combustion of waste as fuel for electricity generation. The study also includes a techno-economical evaluation of the options, using a developed computer simulation tool. The economic indicators of an MSW energy recovery project were calculated. The selected methodology allows to calculate the energy content of the MSW and the CH₄ generated by the landfill, the costs and incomes associated with the energy recovery, the sales of electricity and carbon credits from the Clean Development Mechanism (CDM). The studies were based on urban centres of 100,000, 500,000 and 1,000,000 inhabitants, using the MSW characteristics of the metropolitan region of Belo Horizonte. Two alternatives to recovering waste energy were analyzed: a landfill that used landfill biogas to generate electricity through generator modules and a Waste-to-Energy (WtE) facility also with electricity generation. The results show that power generation projects using landfill biogas in Brazil strongly depend on the existence of a market for emissions reduction credits. The WtE plant projects, due to its high installation, Operation and Maintenance (O&M) costs, are highly dependent on MSW treatment fees. And they still rely on an increase of three times the city taxes to become attractive.     

Towards the estimation of demand for recycling in Chile: The case of Santiago

In developing countries, the recycling of municipal solid waste (MSW) as an alternative to the traditional MSW management requires an economic sustainability valuation. From this perspective, the estimation of demand for recycling is crucial. In this paper, we study the case of recycling MSW in Santiago, Chile. We estimate the relation between the monthly amount of MSW separated voluntarily from apartments located in Santiago and the monthly price required to participate in a municipal recycling program. We consider the transference of the municipal cost savings to the owners of the apartments due to the amount of MSW separated for recycling, which is not collected and deposited in the current MSW system. For the estimation, we use concepts from environmental economics and psychology, analyzing the operation and municipal costs incurred by current MSW management and designing and applying a survey based on a contingent valuation method (CVM) approach. The results indicate that the percentage of MSW separated for recycling varies between a 27.98% and 33.18%, that only four MSW types are affected by a variation of the monthly price, and that a reduction of monthly collection trips in the current MSW system from 24 to 18 can be obtained. Additionally, we discuss a number of methodological aspects to be considered in a similar study of valuation of recycling in developing countries. Our conclusion is that Santiago has favorable conditions for the implementation of a recycling program as an alternative to the current MSW system.     

Is Municipal Solid Waste Recycling Economically Efficient?

It has traditionally been argued that recycling municipal solid waste (MSW) is usually not economically viable and that only when externalities, long-term dynamic considerations, and/or the entire product life cycle are taken into account, recycling becomes worthwhile from a social point of view. This article explores the results of a wide study conducted in Israel in the years 2000–2004. Our results reveal that recycling is optimal more often than usually claimed, even when externality considerations are ignored. The study is unique in the tools it uses to explore the efficiency of recycling: a computer-based simulation applied to an extensive database. We developed a simulation for assessing the costs of handling and treating MSW under different waste-management systems and used this simulation to explore possible cost reductions obtained by designating some of the waste (otherwise sent to landfill) to recycling. We ran the simulation on data from 79 municipalities in Israel that produce over 60% of MSW in Israel. For each municipality, we were able to arrive at an optimal method of waste management and compare the costs associated with 100% landfilling to the costs born by the municipality when some of the waste is recycled. Our results indicate that for 51% of the municipalities, it would be efficient to adopt recycling, even without accounting for externality costs. We found that by adopting recycling, municipalities would be able to reduce direct costs by an average of 11%. Through interviews conducted with representatives of municipalities, we were also able to identify obstacles to the utilization of recycling, answering in part the question of why actual recycling levels in Israel are lower than our model predicts they should be.     

Microfiltration of pretreated sanitary landfill leachate

A laboratory study using a bench scale model of two units operation involving coagulation process with Moringa oleifera seeds extract as a coagulant and filtration process using hollow fibre microfiltration membrane, was adopted to treat Air Hitam Sanitary Landfill leachate in Puchong, Malaysia. The performance of the microfiltration membrane in pretreated sanitary landfill leachate treatment was investigated through a continuous process. The leachate sample was passed through conventional coagulation process before being filtered through a hollow fibre microfiltration membrane of 0.1 μm surface pores. The hollow fibre microfiltration membrane decreased the turbidity, colour, total suspended solids, total dissolved solids and volatile suspended solids in the leachate by 98.30, 90.30, 99.63, 14.71 and 20%, respectively. The results showed that microfiltration is capable of removing high percentage of solids from leachate and might be considered as a polishing stage after on-site biological treatment for sanitary landfill leachate.     

渗滤液回灌在实际应用中应注意的问题

本文介绍了垃圾填埋场渗滤液回灌的机理、优缺点,“干填埋”与“湿填埋”之间的区别。渗滤液回灌可增加填埋废物的含水率,加快垃圾的降解速率,减少渗滤液的处理时间,提高填埋气中甲烷的含量,加速填埋场稳定化进程。鉴于以上这些优点,渗滤液回灌作为一种渗滤液处理方式将会有极大的应用前景。但在实际应用中回灌的渗滤液容易泄漏而导致地下水污染,这是影响渗滤液回灌广泛应用的主要原因。为了避免使地下水受污染,本文总结和分析了渗滤液回灌在实际应用中应注意的问题。     

Municipal solid waste management in China: Status,problems and challenges

This paper presents an examination of MSW generation and composition in China, providing an overview of the current state of MSW management, an analysis of existing problems in MSW collection, separation, recycling and disposal, and some suggestions for improving MSW systems in the future. In China, along with urbanization, population growth and industrialization, the quantity of municipal solid waste (MSW) generation has been increasing rapidly. The total MSW amount increased from 31.3 million tonnes in 1980 to 212 million tonnes in 2006, and the waste generation rate increased from 0.50 kg/capita/day in 1980 to 0.98 kg/capita/year in 2006. Currently, waste composition in China is dominated by a high organic and moisture content, since the concentration of kitchen waste in urban solid waste makes up the highest proportion (at approximately 60%) of the waste stream. The total amount of MSW collected and transported was 148 million tonnes in 2006, of which 91.4% was landfilled, 6.4% was incinerated and 2.2% was composted. The overall MSW treatment rate in China was approximately 62% in 2007. In 2007, there were 460 facilities, including 366 landfill sites, 17 composing plants, and 66 incineration plants. This paper also considers the challenges faced and opportunities for MSW management in China, and a number of recommendations are made aimed at improving the MSW management system.     

Regionalization of Municipal Solid Waste Management in Japan: Balancing the Proximity Principle with Economic Efficiency

The proximity principle—disposing of waste close to its origin—has been a central value in municipal solid waste (MSW) management in Japan for the last 30 years and its widespread adoption has helped resolve numerous “Not in My Backyard” issues related to MSW management. However, MSW management costs have soared, in large part because of aggressive recycling efforts and because most MSW is incinerated in a country that has scarce landfill capacity. In addition, smaller, less sophisticated incinerators have been closed because of high dioxin emissions. Rising costs combined with the closure of smaller incinerators have shifted MSW management policy toward regionalization, which is the sharing of waste management facilities across municipalities. Despite the increased use of regionalized MSW facilities, the proximity principle remains the central value in Japanese MSW management. Municipal solid waste management has become increasingly regionalized in the United States, too, but different driving forces are at work in these two countries. The transition to regionalized MSW management in Japan results from strong governmental control at all levels, with the central government providing funds and policy direction and prefectures and municipalities being the primary implementing authorities. By contrast, market forces are a much stronger force with US MSW management, where local governments—with state government oversight—have primary responsibility for MSW management. We describe recent changes in Japan’s MSW programs. We examine the connections between MSW facility regionalization, on the one hand, and, on the other hand, the proximity principle, coordination among local governments, central government control, and financing mechanisms.     

Solid waste management in urban areas: Development and application of a decision support system

A decision support system (DSS) developed to assist the planner in decisions concerning the overall management of solid waste at a municipal scale is described. The DSS allows to plan the optimal number of landfills and treatment plants, and to determine the optimal quantities and the characteristics of the refuse that has to be sent to treatment plants, to landfills and to recycling. The application of the DSS is based on the solution of a constrained non-linear optimization problem. Various classes of constraints have been introduced in the problem formulation, taking into account the regulations about the minimum requirements for recycling, incineration process requirements, sanitary landfill conservation, and mass balance. The cost function to be minimized includes recycling, transportation and maintenance costs. The DSS has been tested on the municipality of Genova, Italy, and the results obtained are presented.     

Questioning the Waste Hierarchy: The Case of a Region with a Low Population Density

Discussions of municipal solid waste (MSW) management are influenced increasingly by the concept of the waste hierarchy which, broadly speaking, places landfill as the least acceptable option for dealing with MSW, followed by incineration, recycling, re-use and reduction at source. In this paper, we want to question the wisdom of applying the waste hierarchy in a region with a low population density. The hierarchy was first developed with reference to the high population density areas such as the core of the EU. However, in low population density areas the economics of the various approaches to MSW is likely to be quite different. As a result, the application of the hierarchy could place an undue economic burden on a region relative to the environmental benefits that might arise. We estimate the costs, both internal and external, of the various methods of dealing with MSW in an area with the appropriate population density, drawing on information from a wide variety of sources. We find that landfill is significantly cheaper than in high population density areas, even when account is taken of the associated externalities. In addition, it is generally cheaper than the alternative methods. As such, we conclude that landfill should not be shunned as a disposal method in low population density areas.     

Analysis of volatile and semivolatile hydrocarbons recovered from steam-classified municipal solid waste

Hazardous household wastes comprise a significant proportion of municipal solid waste (MSW), and therefore serve as the source of many toxic or carcinogenic organic chemicals that are released in the environment through landfill gases or leachates. In the present study, we demonstrate the utility of the steam classification process in removing hazardous semivolatile organic compounds (SVOCs) and volatile organic compounds (VOCs) from MSW. Steam classification is a patented technology that involves the treatment of MSW with steam under pressure to yield a cellulosic biomass product that can be used as a fuel or in building materials. The SVOCs and VOCs from the waste off-gases are collected in the steam condensate and in an effluent charcoal filter. The results of this study show that at least two SVOCs and at least 17 VOCs can be removed from the waste. The most commonly identified compounds were diethylphthalate, styrene, 1,4-dichlorobenzene, and toluene in the condensates, and styrene, 1,1,1-trichloroethane, and toluene in the charcoal filters. On a weight basis, aromatic hydrocarbons were primarily recovered in the condensates, while the chloroaliphatic hydrocarbons were recovered almost exclusively from the charcoal filters. 1,3-Dichlorobenzene, 1,4-dichlorobenzene, and chloroform together comprised nearly 50% of the 4470 micrograms kg(-1) average mass of SVOCs and VOCs recovered from about 454 kg of MSW in these experiments. Toxicity characteristic leaching procedure (TCLP) analyses showed that steam classification recovered at least 75 to 91% of tested analytes. Overall, these results suggest that steam classification represents an effective technology for a significant reduction or the removal of hazardous organics from the waste stream, and, consequently, in reducing the extent of environmental contamination associated with landfill leachates and gases.     

Economic considerations for wastewater upgrading alternatives: an Israeli test case

Sewage effluent for land application is becoming an increasingly important source of irrigation water in many semi-arid regions of the world. Two main approaches to the use of sanitation to upgrade effluent for reuse in agriculture were analyzed: (i) sanitizing to the level required for each crop; or (ii) upgrading all effluent to the sanitary level mandated for unrestricted irrigation (<10 fecal coli/100mL). The first approach was authorized by the Israeli health authorities, who consider irrigation with secondary effluent to be complementary to the treatment process. The other approach was conceived mainly by the agricultural and environmental establishments, which debited the additional financial burden to the urban sector and/or the 'general public'. We show that upgrading all effluents in Israel to 'unrestricted irrigation quality' would cost $69 million each year for upgrading alone, in addition to the costs of treatment to the sanitary level required for each individual crop and of observing all the necessary additional precautions and boundaries. This difference in cost stems from the fact that most effluent is used for the irrigation of non-edible crops, for which partial pathogen removal is sufficient. Thus, upgrading to the sanitary level required by the most sensitive crops would be rather wasteful.     

垃圾渗滤液中氨氮去除技术评价及应用

垃圾卫生填埋过程中会产生有毒有害的垃圾渗滤液。垃圾渗滤液中的高氨氮对环境及后续生物处理过程造成了严重的影响。本文介绍了几种去除垃圾渗滤液氨氮的技术,并对这些技术进行了评估,分析了这些技术工程应用的特点,同时指出了垃圾渗滤液中氨氮去除技术工程应用的发展方向。     

城市垃圾填埋场渗滤液处理工艺综述

城市垃圾对环境的影响越来越严重，垃圾填埋导致垃圾渗滤液的大量产生，渗滤液中含有大量的有机物、大量的病菌、病毒、寄生虫等以及一些有毒有害的物质，若渗滤液不加以妥善处理、肆意排放，必将对地下水、地表水构成严重威胁，因此垃圾渗滤液的有效处理就成为一个亟待解决的问题。本文对城市垃圾填埋场渗滤液的处理工艺进行了分析和探讨，介绍了国内外垃圾渗滤液处理的主要技术，包括土地处理法、生物法和物化法，并对电解法处理垃圾渗滤液进行了详细的介绍。     

Clean fuels from municipal solid waste for fuel cell buses in metropolitan areas

Increasing volumes of municipal solid waste (MSW) pose disposal problems for many cities. Costs are rising as landfilling becomes more difficult. The production of clean transportation fuels (methanol or hydrogen) from MSW is one economically and environmentally promising option for dealing with these problems. An attractive feature is that elimination of essentially all air pollutant emissions is inherent in the process. Current and future air emissions standards should be easily met. Methanol or hydrogen used in fuel cell vehicles (FCV) can help address problems of deteriorating urban air quality due to vehicle pollution and heavy dependence of the transport sector on imported petroleum. Buses are initial targets for commercial application of fuel cells. Coupled with FCVs, MSW could become a major transportation energy resource. For example, less than 25% of New York City's MSW supply would be sufficient to produce the methanol or hydrogen needed to fuel the entire city's bus fleet, if the buses were fuel cell powered. Estimated breakeven tipping fees required for hydrogen or methanol from MSW to compete with the cost of these fuels made from natural gas today are $52 to $89/raw tonne MSW for hydrogen and $64 to $104/raw tonne MSW for methanol (in 1991$), depending on the gasification technology considered. For comparison, the average tipping fee today in New York City is $74/tonne (1991$). Because of the high fuel economies expected for fuel cell buses, total lifecycle costs per bus-km could be lower than for conventional diesel-engine buses.     

A cost and benefit analysis of future end-of-life vehicle glazing recycling in France: A systematic approach

As with other European countries, the French automotive industry needs to improve the end-of-life vehicle (ELV) recycling rate in order to reach the minimum reuse and recovery rate required by EU directives. This paper proposes a model to investigate the potential cost and benefit of ELV glazing recycling for all value-chain stakeholders, and for the network as a whole. Key parameters of future changes, namely glass cullet price, landfill cost, network coverage and transportation costs are identified at the level of field research. A system dynamics approach is then used to simulate the net economic balance of the recycling network under different future scenarios. The simulation reveals an increase in the income and considerable cost savings as a result of the recycling network in some of future scenarios.     

Application of the analytic hierarchy process to compare alternatives for the long-term management of surplus mercury

This paper describes a systematic method for comparing options for the long-term management of surplus elemental mercury in the US, using the analytic hierarchy process as embodied in commercially available Expert Choice software. A limited scope multi-criteria decision analysis was performed. Two (2) general types of treatment technologies were evaluated (stabilization/amalgamation and selenide), combined with four (4) disposal options: (a) hazardous waste landfill; (b) hazardous waste monofill; (c) engineered below-ground structure; and (d) mined cavity. In addition, three storage options for elemental mercury were considered: (a) aboveground structure; (b) hardened structure; and (c) mined cavity. Alternatives were evaluated against criteria that included costs, environmental performance, compliance with current regulations, implementation considerations, technology maturity, potential risks to the public and workers, and public perception. Considering non-cost criteria only, the three storage options rank most favorably. If both cost and other criteria are considered, then landfill options are preferred, because they are the least expensive ones. Storage options ranked unfavorably on cost because: (a) even relatively small per annum costs will add up over time; and (b) storage is a temporary solution and, sooner or later, a treatment and disposal technology will be adopted, which adds to the cost. However, the analysis supports continued storage for a short period (up to a few decades) followed by permanent retirement when treatment technologies have matured. Suggestions for future work include: (a) involving additional stakeholders in the process, (b) evaluating alternatives for mercury-containing wastes rather than for elemental mercury only, (c) revisiting the analysis periodically to determine if changes are required, (d) conducting uncertainty analyses utilizing Monte Carlo-based techniques.     

GIS and the Analytic Hierarchy Process for Regional Landfill Site Selection in Transitional Countries: A Case Study From Serbia

The Serbian National Waste Management Strategy for the Period 2010–2019, harmonized with the European Union Directives, mandates new and very strict requirements for landfill sites. To enable analysis of a number of required qualitative and quantitative factors for landfill site selection, the traditional method of site selection must be replaced with a new approach. The combination of GIS and the Analytic Hierarchy Process (AHP) was selected to solve this complex problem. The Srem region in northern Serbia, being one of the most environmentally sensitive areas, was chosen as a case study. Seventeen factors selected as criteria/sub-criteria were recognized as most important, divided into geo-natural, environmental, social and techno-economic factors, and were evaluated by experts from different fields using an AHP extension in Arc GIS. Weighted spatial layers were combined into a landfill suitability map which was then overlapped with four restriction maps, resulting in a final suitability map. According to the results, 82.65% of the territory of Srem is unsuitable for regional landfill siting. The most suitable areas cover 9.14%, suitable areas 5.24%, while areas with low and very low suitability cover 2.21 and 0.76% of the territory, respectively. Based on these findings, five sites close to two large urban agglomerations were suggested as possible locations for a regional landfill site in Srem. However, the final decision will require further field investigation, a public acceptance survey, and consideration of ownership status and price of the land.