城市生活垃圾综合管理决策研究进展

城市生活垃圾综合管理主要是指选择合适的方案、政策手段等来实现特定的管理目标。选择适宜的研究方法是开展城市生活垃圾管理科学决策的重要基础和保障。综述了近年来该领域常用的相关研究方法和研究进展,总结分析了以统计分析、多准则决策分析、全生命周期分析、费用效益分析等为代表的传统数学模型方法和以系统动力学、基于Agent的建模等为代表的复杂系统模拟方法两大类方法的适用场景、优缺点和研究进展,分析了未来该领域研究的趋势和需重点关注的方向。研究发现：传统的数学模型方法被广泛应用于生活垃圾管理决策领域,成为支撑决策的重要研究工具,但这类方法通常大多以单一主体为研究对象,难以解释各种因素对其它主体及整个生活垃圾管理系统的作用,且大多为静态的或对某个或某几个时间点进行分析,容易忽略系统性和系统中各主体间的非线性关系、行为的交互作用及随时空的动态变化等。未来研究需充分关注城市生活垃圾管理系统的复杂性和系统不同主体间的行为交互作用,加强系统模拟模型开发,开展系统性政策评估分析等,为城市生活垃圾精细化管理决策提供科学支撑。     

Integrated municipal waste management systems: An indicator to assess their environmental and economic sustainability

Tools based on Life Cycle Thinking (LCT) are routinely used to assess the environmental and economic performance of integrated municipal solid waste (MSW) management systems. Life Cycle Assessment (LCA) is used to quantify the environmental impacts, whereas Life Cycle Costing (LCC) allows financial and economic assessments. These tools require specific experience and knowledge, and a large amount of data.The aim of this project is the definition of an indicator for the assessment of the environmental and economic sustainability of integrated MSW management systems. The challenge is to define a simple but comprehensive indicator that may be calculated also by local administrators and managers of the waste system and not only by scientists or LCT experts.The proposed indicator is a composite one, constituted by three individual indicators: two of them assess the environmental sustainability of the system by quantifying the achieved material and energy recovery levels, while the third one quantifies the costs. The composite indicator allows to compare different integrated MSW management systems in an objective way, and to monitor the performance of a system over time.The calculation of the three individual indicators has been tested on the integrated MSW management systems of the Lombardia Region (Italy) as well as on four of its provinces (Milano, Bergamo, Pavia, and Mantova).     

The application of an life cycle inventory (LCI) model for solid waste disposal systems in malaysia

This paper discusses the application of an LCt model for solid waste management systems in Malaysia. The model was used to analyze the environmental and economic impacts of municipal waste management systems in Malaysia. In the first part of the study, the LCI model was adapted to analyze waste management systems of four selected cities: Kuala Lumpur and Penang to represent urban areas; Seremban to represent moderately urban areas and Muar to represent rural areas. The results have shown that Kuala Lumpur and Penang had greater Global Warming Potential (GWP) and the costs spent on the solid waste management were also higher as compared to that in suburban areas. In the second part of the study, a detailed evaluation was carried out by analyzing the implication of introducing incineration and composting into the solid waste management system, and the results were compared with the current system, i.e. 100 % landfilled. The relative GWP was lower for incineration, but the cost was extremely high. The results also showed that the final solid waste to be disposed to landfills and the impact due to water emissions could be reduced significantly when incineration and composting were introduced.     

城市生活垃圾代谢的研究进展

城市代谢是导致城市发展、能量生产和废物排放的社会、经济和技术过程的总和。生活垃圾管理系统是一类典型的、具备社会、经济、自然要素的复杂系统,它不仅同管理体制、技术水平和居民素质有关,也贯穿生产、消费、流通、还原过程,更和水体、土壤、大气、生物、矿产等自然环境紧密联系。综述了近年来基于城市生态系统代谢思路,在生活垃圾碳、重金属、营养元素和能量的城市代谢等方面的研究进展,分析了未来该领域研究需重点关注的方向。生活垃圾在城市生态系统中的能量流动、物质循环、代谢效率等方面的研究,可为生活垃圾管理系统的评价、规划、工程、管理研究提供科学基础。     

The impact of landfilling and composting on greenhouse gas emissions – A review

Municipal solid waste is a significant contributor to greenhouse gas emissions through decomposition and life-cycle activities processes. The majority of these emissions are a result of landfilling, which remains the primary waste disposal strategy internationally. As a result, countries have been incorporating alternative forms of waste management strategies such as energy recovery from landfill gas capture, aerobic landfilling (aerox landfills), pre-composting of waste prior to landfilling, landfill capping and composting of the organic fraction of municipal solid waste. As the changing global climate has been one of the major environmental challenges facing the world today, there is an increasing need to understand the impact of waste management on greenhouse gas emissions. This review paper serves to provide an overview on the impact of landfilling (and its various alternatives) and composting on greenhouse gas emissions taking into account streamlined life cycle activities and the decomposition process. The review suggests greenhouse gas emissions from waste decomposition are considerably higher for landfills than composting. However, mixed results were found for greenhouse gas emissions for landfill and composting operational activities. Nonetheless, in general, net greenhouse gas emissions for landfills tend to be higher than that for composting facilities.     

Environmental Assessment of Two Waste Incineration Strategies for Central Norway (10 pp)

Background, Aims and Scope A strategy of local incineration with 17 small incinerators (Scenario L) is compared to a strategy of 3 centralized waste incinerators (Scenario C) for the region of Central Norway, in order to assess differences in environmental performance. Rough calculations of costs are also included. The functional unit is the treatment of municipal, commercial and special waste not recycled, plus the heating of a specific number of households, for the period of 2002 to 2020. Methods Data on large and small scale incinerators were obtained from technology providers. LCA databases were used for transportation and heating, while cost estimates and Norwegian input-output tables were used for the construction of the facilities. The CML2 method was used to evaluate the impacts. Results and Discussion Transportation is a major contributor to aquatic toxicity and acidification as well as CO2 emissions. Impacts from construction are considerable for photochemical oxidation, while incineration is important for terrestrial toxicity and CO2 emissions. Conclusion Construction and operation of treatment facilities are, together with transportation, the main processes making a difference between the two strategies. Substantial gains will come from the reduction in transportation need when introducing a local incineration strategy. When considering a time span of two decades, the centralized scenario is about 2.5 to 5 times the impact potential of the local scenario for most impact categories, in terms of cumulative results. Cost estimates for the two solutions support these findings, as cumulated costs also favors a local solution. Recommendation and Outlook Transportation is a major contributor to several impact categories, and especially the transportation of special waste should become more efficient in terms of transportation distances. Cost estimates support the environmental assessment, but a more comprehensive economic study of the system would be valuable.     

LCA application to integrated waste management planning in Gipuzkoa (Spain)

Goal, Scope and Background  Gipuzkoa is a department of the Vasque Country (Spain) with a population of about 700,000 people. By the year 2000 approximately 85% of municipal solid waste in this area was managed by landfilling, and only 15% was recycled. Due to environmental law restrictions and landfill capacity being on its limit, a planning process was initiated by the authorities. LCA was used, from an environmental point of view, to assess 7 possible scenarios arising from the draft Plan for the 2016 time horizon. Main Features  In each scenario, 9 waste flows are analysed: rest waste, paper and cardboard, glass containers, light packaging, organic-green waste, as well as industrial/commercial wood, metals and plastics, and wastewater sludge. Waste treatments range from recycling to energy recovery and landfilling. Results  Recycling of the waste flows separated at the source (paper and cardboard, glass, light packaging, organic-green waste, wood packaging, metals and plastics) results in net environmental benefits caused by the substitution of primary materials, except in water consumption. These benefits are common to the 7 different scenarios analysed. However, some inefficiencies are detected, mainly the energy consumption in collection and transport of low density materials, and water consumption in plastic recycling. The remaining flows, mixed waste and wastewater sludge, are the ones causing the major environmental impacts, by means of incineration, landfilling of partially stabilised organic material, as well as thermal drying of sludge. With the characterisation results, none of the seven scenarios can be clearly identified as the most preferable, although, due to the high recycling rates expected by the Plan, net environmental benefits are achieved in 9 out of 10 impact categories in all scenarios when integrated waste management is assessed (the sum of the 9 flows of waste). Finally, there are no relevant differences between scenarios concerning the number of treatment plants considered. Nevertheless, only the effects on transportation impacts were assessed in the LCA, since the plant construction stage was excluded from the system boundaries. Conclusions  The results of the study show the environmental importance of material recycling in waste management, although the recycling schemes assessed can be improved in some aspects. It is also important to highlight the environmental impact of incineration and landfilling of waste, as well as thermal drying of sludge using fossil fuels. One of the main findings of applying LCA to integrated waste management in Gipuzkoa is the fact that the benefits of high recycling rates can compensate for the impacts of mixed waste and wastewater sludge. Recommendations and Outlook  Although none of the scenarios can be clearly identified as the one having the best environmental performance, the authorities in Gipuzkoa now have objective information about the future scenarios, and a multidisciplinary panel could be formed in order to weight the impacts if necessary. In our opinion, LCA was successfully applied in Gipuzkoa as an environmental tool for decision making.     

Material Flow Optimization in By‐product Synergy Networks

By‐product synergy (BPS) is an industrial ecology practice that involves utilization of industrial by‐products as feedstocks for other industrial processes. A novel decision support tool is developed to analyze BPS networks that involve material processing and transport among regional clusters of companies. Mathematical programming techniques are used to determine the optimal network design and the material flows that minimize total cost or environmental impacts. This methodology is incorporated into a graphical software package called Eco‐Flow?. The tool has been applied to model and analyze available synergies in an existing BPS network centered in Kansas City, Missouri. A base case, which assumes no synergies, is compared with the optimal BPS solution found by Eco‐Flow?. The results for Kansas City suggest that when companies in the network cooperate to optimize the system profitability, up to $15 million per year of savings are possible. The findings also indicate that the BPS approach would result in 29% reduction in total cost, 25.8% reduction in average company cost, 30% reduction in carbon dioxide (CO₂) emissions, and 37% reduction in waste to landfill. The modeling approach is being extended to better represent the dynamics of industrial and ecological processes.     

A Decision Support Framework for Sustainable Waste Management

This article describes a decision support framework for the evaluation of scenarios for the integrated management of municipal solid waste within a local government area (LGA).
The work is initially focused on local government (i.e., municipal councils) in the state of Queensland, Australia; however, it is broadly applicable to LGAs anywhere. The goal is to achieve sustainable waste management practices by balancing global and regional environmental impacts, social impacts at the local community level, and economic impacts. The framework integrates life-cycle assessment (LCA) with other environmental, social, and economic tools. For this study, social and economic impacts are assumed to be similar across developed countries of the world. LCA was streamlined at both the life-cycle inventory and life-cycle impact assessment stages.
For this process, spatial resolution is introduced into the LCA process to account for impacts occurring at the local and regional levels. This has been done by considering social impacts on the local community and by use of a regional procedure for LCA data for emissions to the environment that may have impacts at the regional level.
The integration follows the structured approach of the pressure-state-response (PSR) model suggested by the Organisation for Economic Cooperation and Development (OECD). This PSR model has been extended to encompass nonenvironmental issues and to guide the process of applying multiple tools.
The framework primarily focuses on decision analysis and interpretation processes. Multiattribute utility theory (MAUT) is used to assist with the integration of qualitative and quantitative information. MAUT provides a well-structured approach to information assessment and facilitates objective, transparent decisions. A commercially available decision analysis software package based on MAUT has been used as the platform for the framework developed in this study.     

A Procedure for Life-Cycle-Based Solid Waste Management with Consideration of Uncertainty

The development of integrated solid-waste management (SWM) strategies that are efficient with respect to both cost and environmental performance is a complex task. It must incorporate the numerous interrelations among different unit operations in the solid waste system (e.g., collection, recycling, and combustion), and the large number of design parameters that affect estimates of cost and environmental emissions. Uncertainty in design and operational parameters can lead to uncertainty in the estimates of cost and emissions. This article describes an extension of the capability of the Integrated Solid Waste Management Decision Support Tool (ISWM DST) to enable consideration of the effects of uncertainty in input parameters. The uncertainty analysis capability is illustrated using a hypothetical case study of a typical municipality. Results show that increased expenditure does not necessarily result in a reduction in the expected levels of environmental emissions and that some SWM alternatives may be more robust, although deterministic estimates of their expected performances are similar. The uncertainty analysis also facilitates use of the ISWM DST by policy makers responsible for evaluation of the expected effect of SWM practices on, for example, greenhouse-gas emissions.     

生命周期评价方法在城市生活垃圾管理中的应用研究述评

结合城市生活垃圾管理系统特征,系统归纳基于生命周期评价(Life cycle assessment,LCA)方法的城市生活垃圾管理模型的发展现状,并对LCA方法在城市生活垃圾管理中的实践以及在我国开展城市生活垃圾管理LCA研究的应用前景进行评述。分析表明,LCA是城市生活垃圾管理领域的重要工具之一,基于LCA方法的城市生活垃圾管理模型在全生命周期环境影响评价与识别、处置工艺选择与改进、可持续生活垃圾管理决策支持等方面具有十分重要的应用价值。中国在本地化生活垃圾管理系统LCA模型开发、清单数据库和评价指标体系构建以及与其他研究方法集成等方面面临挑战。     

Assessing the Eco-efficiency of End-of-Pipe Technologies with the Environmental Cost Efficiency Indicator

The concept of eco-efficiency is increasingly being applied to judge the combined environmental and economic performance of product systems, processes, and/or companies. Ecoefficiency is often defined as the ratio of economic value added to environmental impact added. This definition is not appropriate for end-of-pipe treatment technologies because these technologies aim at improving the environmental performance of technical processes at the cost of financial expense. Therefore, an indicator for the assessment of end-of-pipe technologies has been proposed. This indicator, called environmental cost efficiency (ECE), is defined as the ratio of net environmental benefits to the difference in costs. ECE is applied to four end-of-pipe technologies for the treatment of municipal solid waste: sanitary landfill, mechanical-biological treatment, modern grate incineration, and a staged thermal process (pyrolysis and gasification). A life-cycle assessment was performed on these processes to quantify the net environmental benefit. Moreover, the approximate net costs (costs minus benefits) were quantified. The results show that, relative to grate incineration, sanitary landfills and mechanical-biological treatment are less costly but environmentally more harmful. We calculated the ECE for all combinations of technologies. The results indicate that the staged thermal process may be the most environmentally cost-efficient alternative to all other treatment technologies in the long run, followed by mechanical-biological treatment and grate incineration.     

From Life Cycle Assessment to Life Cycle Management

Life cycle assessment (LCA) is a widely accepted methodology to support decision‐making processes in which one compares alternatives, and that helps prevent shifting of environmental burdens along the value chain or among impact categories. According to regulation in the European Union (EU), the movement of waste needs to be reduced and, if unavoidable, the environmental gain from a specific waste treatment option requiring transport must be larger than the losses arising from transport. The EU explicitly recommends the use of LCA or life cycle thinking for the formulation of new waste management plans. In the last two revisions of the Industrial Waste Management Programme of Catalonia (PROGRIC), the use of a life cycle thinking approach to waste policy was mandated. In this article we explain the process developed to arrive at practical life cycle management (LCM) from what started as an LCA project. LCM principles we have labeled the “3/3” principle or the “good enough is best” principle were found to be essential to obtain simplified models that are easy to understand for legislators and industries, useful in waste management regulation, and, ultimately, feasible. In this article, we present the four models of options for the management of waste solvent to be addressed under Catalan industrial waste management regulation. All involved actors concluded that the models are sufficiently robust, are easy to apply, and accomplish the aim of limiting the transport of waste outside Catalonia, according to the principles of proximity and sufficiency.     

Perspectives on the U.S. Paper Industry and Sustainable Production

In the past decade and a half, the U.S. paper industry became the target of an unusual convergence of environmental concerns. These concerns have focused on the industrys role in forest and biodiversity depletion, the municipal solid waste management crisis, and various toxic chemical pollution problems. Although such concerns are traditionally treated as distinct environmental policy areas, the prominence of the paper industvs impacts in each area gave rise to an increasingly integrated environmental perspective fixed on the system of paper production and consumption, and on the paper industry itself. The argument advanced here suggests that the structure of the modem industry itself must be a central focus in a more integrated environmental perspective that can meaningfully accommodate the multiple social, economic, and ecological goals of sustainabilrty. Two issues, paper recycling and the use of nonwood fiber sources, are discussed from this point of view. The article concludes with a discussion of how a sectoral analysis of environmental problems can be Addrw correspondence tot used to frame a comprehensive strategic vision of attemative futures in the industry, and to design effective public policies and strategies     

Influence of assumptions about selection and recycling efficiencies on the LCA of integrated waste management systems

Background, aim, and scope  Life cycle assessment (LCA) applied to alternative waste management strategies is becoming a commonly utilised tool for decision makers. This LCA study analyses together material and energy recovery within integrated municipal solid waste (MSW) management systems, i.e. the recovery of materials separated with the source-separated collection of MSW and the energy recovery from the residual waste. The final aim is to assess the energetic and environmental performance of the entire MSW management system and, in particular, to evaluate the influence of different assumptions about recycling on the LCA results. Materials and methods  The analysis uses the method of LCA and, thus, takes into account that any recycling activity influences the environment not only by consuming resources and releasing emissions and waste streams but also by replacing conventional products from primary production. Different assumptions about the selection efficiencies of the collected materials and about the quantity of virgin material substituted by the reprocessed material were made. Moreover, the analysis considers that the energy recovered from the residual waste displaces the same quantity of energy produced in conventional power plants and boilers fuelled with fossil fuels. Results  The analysis shows, in the expanded model of the material and energy recovering chain, that the environmental gains are higher than the environmental impacts. However, when we reduce the selection efficiencies by 15%, the impact indicators worsen by a percentage included between 10% and 26%. This phenomenon is even more evident when we consider a substitution ratio of 1:<1 for paper and plastic: The worsening is around 15–20% for all the impact indicators except for the global warming for which the worsening is up to 45%. Discussion  Hypotheses about the selection efficiencies of the source-separated collected materials and about the substitution ratio have a great influence on the LCA results. Consequently, policy makers have to be aware of the fact that the impacts of an integrated MSW management system are highly dependent on the assumptions made in the modelling of the material recovery, as well as in the modelling of the energy recovery. Conclusions  LCA allows to evaluate the impacts of integrated systems and how these impacts change when the assumptions made during the modelling of the different single parts of the system are modified. Due to the significant impacts that hypotheses about material recovery have in the results, they should be expressed in a very transparent way in the report of LCA studies, together with the assumptions made about energy recovery. Recommendations and perspectives  The results suggest that the hypotheses about the value of the substitution ratio are very important, and the case of wood should therefore be better analysed and a substitution ratio of 1:<1 should be used, as for paper and plastic. It seems that the assumptions made about which material is replaced by the recycled one are very important too, and in this sense, more research is needed about what the recycled plastic may effectively substitute, in particular the polyolefin mix.     

The assimilation of organic hazardous wastes by municipal solid waste landfills

Summary Co-disposal of 12 compounds representing major organic classes (aromatic hydrocarbons, halogenated hydrocarbons, pesticides, phenols, and phthalate esters) with shredded municipal solid waste was tested using a laboratory-scale column and pilot-scale lysimeter to characterize transport and transformation phenomena including sorption, volatilization and bioassimilation. Leachate and gases emitted from the lysimeters were examined for identifiable products of biotransformation. The results of this investigation provided a mechanistic evaluation of the attenuating and assimilative capacity of municipal solid waste landfills for specific organic compounds. Physical/chemical organic compound characteristics were related to refuse characteristics and composition to predict compound fate. Such knowledge is useful in developíng landfill management and operational strategies consistent with the need for control of pollutant releases.     

Comparative LCAs for Curbside Recycling Versus Either Landfilling or Incineration with Energy Recovery (12 pp)

Background This article describes two projects conducted recently by Sound Resource Management (SRMG) – one for the San Luis Obispo County Integrated Waste Management Authority (SLO IWMA) and the other for the Washington State Department of Ecology (WA Ecology). For both projects we used life cycle assessment (LCA) techniques to evaluate the environmental burdens associated with collection and management of municipal solid waste. Both projects compared environmental burdens from curbside collection for recycling, processing, and market shipment of recyclable materials picked up from households and/or businesses against environmental burdens from curbside collection and disposal of mixed solid waste. Method logy. The SLO IWMA project compared curbside recycling for households and businesses against curbside collection of mixed refuse for deposition in a landfill where landfill gas is collected and used for energy generation. The WA Ecology project compared residential curbside recycling in three regions of Washington State against the collection and deposition of those same materials in landfills where landfill gas is collected and flared. In the fourth Washington region (the urban east encompassing Spokane) the WA Ecology project compared curbside recycling against collection and deposition in a wasteto- energy (WTE) combustion facility used to generate electricity for sale on the regional energy grid. During the time period covered by the SLO study, households and businesses used either one or two containers, depending on the collection company, to separate and set out materials for recycling in San Luis Obispo County. During the time of the WA study households used either two or three containers for the residential curbside recycling programs surveyed for that study. Typically participants in collection programs requiring separation of materials into more than one container used one of the containers to separate at least glass bottles and jars from other recyclable materials. For the WA Ecology project SRMG used life cycle inventory (LCI) techniques to estimate atmospheric emissions of ten pollutants, waterborne emissions of seventeen pollutants, and emissions of industrial solid waste, as well as total energy consumption, associated with curbside recycling and disposal methods for managing municipal solid waste. Emissions estimates came from the Decision Support Tool (DST) developed for assessing the cost and environmental burdens of integrated solid waste management strategies by North Carolina State University (NCSU) in conjunction with Research Triangle Institute (RTI) and the US Environmental Protection Agency (US EPA)1. RTI used the DST to estimate environmental emissions during the life cycle of products. RTI provided those estimates to SRMG for analysis in the WA Ecology project2. For the SLO IWMA project SRMG also used LCI techniques and data from the Municipal Solid Waste Life- Cycle Database (Database), prepared by RTI with the support of US EPA during DST model development, to estimate environmental emissions from solid waste management practices3. Once we developed the LCI data for each project, SRMG then prepared a life cycle environmental impacts assessment of the environmental burdens associated with these emissions using the Environmental Problems approach discussed in the methodology section of this article. Finally, for the WA study we also developed estimates of the economic costs of certain environmental impacts in order to assess whether recycling was cost effective from a societal point of view. Conclusions Recycling of newspaper, cardboard, mixed paper, glass bottles and jars, aluminum cans, tin-plated steel cans, plastic bottles, and other conventionally recoverable materials found in household and business municipal solid wastes consumes less energy and imposes lower environmental burdens than disposal of solid waste materials via landfilling or incineration, even after accounting for energy that may be recovered from waste materials at either type disposal facility. This result holds for a variety of environmental impacts, including global warming, acidification, eutrophication, disability adjusted life year (DALY) losses from emission of criteria air pollutants, human toxicity and ecological toxicity. The basic reason for this conclusion is that energy conservation and pollution prevention engendered by using recycled rather than virgin materials as feedstocks for manufacturing new products tends to be an order of magnitude greater than the additional energy and environmental burdens imposed by curbside collection trucks, recycled material processing facilities, and transportation of processed recyclables to end-use markets. Furthermore, the energy grid offsets and associated reductions in environmental burdens yielded by generation of energy from landfill gas or from waste combustion are substantially smaller then the upstream energy and pollution offsets attained by manufacturing products with processed recyclables, even after accounting for energy usage and pollutant emissions during collection, processing and transportation to end-use markets for recycled materials. The analysis that leads to this conclusion included a direct comparison of the collection for recycling versus collection for disposal of the same quantity and composition of materials handled through existing curbside recycling programs in Washington State. This comparison provides a better approximation to marginal energy usage and environmental burdens of recycling versus disposal for recyclable materials in solid waste than does a comparison of the energy and environmental impacts of recycling versus management methods for handling typical mixed refuse, where that refuse includes organics and non-recyclables in addition to whatever recyclable materials may remain in the garbage. Finally, the analysis also suggests that, under reasonable assumptions regarding the economic cost of impacts from pollutant emissions, the societal benefits of recycling outweigh its costs.     

A multi-criteria ranking of different technologies for the anaerobic digestion for energy recovery of the organic fraction of municipal solid wastes

This paper describes a conceptual framework and methodological tool developed for the evaluation of different anaerobic digestion technologies suitable for treating the organic fraction of municipal solid waste, by introducing the multi-criteria decision support method Electre III and demonstrating its related applicability via a test application. Several anaerobic digestion technologies have been proposed over the last years; when compared to biogas recovery from landfills, their advantage is the stability in biogas production and the stabilization of waste prior to final disposal. Anaerobic digestion technologies also show great adaptability to a broad spectrum of different input material beside the organic fraction of municipal solid waste (e.g. agricultural and animal wastes, sewage sludge) and can also be used in remote and isolated communities, either stand-alone or in conjunction to other renewable energy sources. Main driver for this work was the preliminary screening of such methods for potential application in Hellenic islands in the municipal solid waste management sector. Anaerobic digestion technologies follow different approaches to the anaerobic digestion process and also can include production of compost. In the presented multi-criteria analysis exercise, Electre III is implemented for comparing and ranking 5 selected alternative anaerobic digestion technologies. The results of a performed sensitivity analysis are then discussed. In conclusion, the performed multi-criteria approach was found to be a practical and feasible method for the integrated assessment and ranking of anaerobic digestion technologies by also considering different viewpoints and other uncertainties of the decision-making process.     

广州市固体废物管理与处置现状及对策

分析广州市工业固体废物、危险废物、生活垃圾、余泥渣土等管理与处置现状,揭示广州市现有固体废物管理处置存在的主要问题,并提出对策建议。分析表明,近年广州市工业固体废物年产生量呈上升趋势,工业固体废物排放量有所回升;1999年危险废物实现零排放,医疗垃圾的集中处置率达100%;居民生活垃圾清运处置率达100%。生活垃圾分类收集率为26%,加快了垃圾填埋场的改造和建设;余泥渣土的管理逐步规范化,市区余泥渣土排放工地申领排放证率保持100%。存在问题包括管理上欠长远规划、处置技术落后、二次污染、资源回收率低、资金匮乏等,尤其缺乏对危险废物、废旧电池的集中处置机构。     

Use of Incinerator Bottom Ash for Frit Production

This article presents the results of an experimental activity aimed at investigating the technical feasibility and the environmental performance of using municipal solid waste incineration bottom ash to produce glass frit for ceramic glaze (glaze frit). The process includes an industrial pretreatment of bottom ash that renders the material suitable for use in glaze frit production and allows recovery of aluminum and iron. The environmental performance of this treatment option is assessed with the life cycle assessment (LCA) methodology. The goal of the LCA study is to assess and compare the environmental impacts of two scenarios of end of life of bottom ash from municipal solid waste incineration (MSWI): landfill disposal (conventional scenario) and bottom ash recovery for glaze frit production (innovative scenario). The main results of the laboratory tests, industrial simulations, and LCA study are presented and discussed, and the environmental advantages of recycling versus landfill disposal are highlighted.