深圳玉龙坑垃圾填埋场填埋气体产生量预测研究

通过综合垃圾填埋量、垃圾组分、以及气候特点等因素，采用二阶段复合产气速率模型对玉龙坑填埋场封场前后填埋气体产生量情况进行了预测。预测结果表明玉龙坑填埋场在封场后10年内仍有较大量的填埋气体产生，若不加以妥善处理将会产生安全隐患，若加以利用会产生经济效益。该模型的应用可为垃圾填埋场进行填埋气体产生量预测及收集处理系统的设计、管理提供合理的依据。     

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。     

LCA: A decision support tool for environmental assessment of MSW management systems

Life cycle assessment (LCA) can be successfully applied to municipal solid waste (MSW) management systems to identify the overall environmental burdens and to assess the potential environmental impacts. In this study, two methods used for current MSW management in Phuket, a province of Thailand, landfilling (without energy recovery) and incineration (with energy recovery), are compared from both energy consumption and greenhouse gas emission points of view. The comparisons are based on a direct activity consideration and also a life cycle perspective. In both cases as well as for both parameters considered, incineration was found to be superior to landfilling. However, the performance of incineration was much better when a life cycle perspective was used. Also, landfilling reversed to be superior to incineration when methane recovery and electricity production were introduced. This study reveals that a complete picture of the environmental performance of MSW management systems is provided by using a life cycle perspective.     

Environmental and economic impact assessment of construction and demolition waste disposal using system dynamics

Construction and demolition wastes (CDW) have increasingly serious problems in environmental, social, and economic realms. There is no coherent framework for utilization of these wastes which are disposed both legally and illegally. This harms the environment, contributes to the increase of energy consumption, and depletes finite landfills resources. The aim of this paper is to evaluate the impacts of two alternatives for the management of CDW, recycling and disposing. The evaluation is carried out through developing a dynamic model with aid STELLA software by conducting the following steps: (1) quantifying the total cost incurred to mitigate the impacts of CDW landfills and uncollected waste on the environment and human health; (2) quantifying the total avoided emissions and saved energy by recycling waste; (3) estimating total external cost saved by recycling waste and; (4) providing a decision support tool that helps in re-thinking about waste disposal. The proposed evaluation methodology allows activating the stringent regulations that restrict waste disposal and developing incentives to encourage constructors to recycle their wastes. The research findings show that recycling CDW leads to significant reductions in emissions, energy use, global warming potential (GWP), and conserves landfills space when compared to disposal of wastes in landfills. Furthermore, the cost of mitigating the impact of disposal is extremely high. Therefore, it is necessary to recycle construction and demolition wastes.     

Assessment of the greenhouse effect impact of technologies used for energy recovery from municipal waste: A case for England

Waste management activities contribute to global greenhouse gas emissions approximately by 4%. In particular the disposal of waste in landfills generates methane that has high global warming potential. Effective mitigation of greenhouse gas emissions is important and could provide environmental benefits and sustainable development, as well as reduce adverse impacts on public health. The European and UK waste policy force sustainable waste management and especially diversion from landfill, through reduction, reuse, recycling and composting, and recovery of value from waste. Energy from waste is a waste management option that could provide diversion from landfill and at the same time save a significant amount of greenhouse gas emissions, since it recovers energy from waste which usually replaces an equivalent amount of energy generated from fossil fuels. Energy from waste is a wide definition and includes technologies such as incineration of waste with energy recovery, or combustion of waste-derived fuels for energy production or advanced thermal treatment of waste with technologies such as gasification and pyrolysis, with energy recovery. The present study assessed the greenhouse gas emission impacts of three technologies that could be used for the treatment of Municipal Solid Waste in order to recover energy from it. These technologies are Mass Burn Incineration with energy recovery, Mechanical Biological Treatment via bio-drying and Mechanical Heat Treatment, which is a relatively new and uninvestigated method, compared to the other two. Mechanical Biological Treatment and Mechanical Heat Treatment can turn Municipal Solid Waste into Solid Recovered Fuel that could be combusted for energy production or replace other fuels in various industrial processes. The analysis showed that performance of these two technologies depends strongly on the final use of the produced fuel and they could produce GHG emissions savings only when there is end market for the fuel. On the other hand Mass Burn Incineration generates greenhouse gas emission savings when it recovers electricity and heat. Moreover the study found that the expected increase on the amount of Municipal Solid Waste treated for energy recovery in England by 2020 could save greenhouse gas emission, if certain Energy from Waste technologies would be applied, under certain conditions.     

Management of urban solid waste: Vermicomposting a sustainable option

Solid waste management is a worldwide problem and it is becoming more and more complicated day by day due to rise in population, industrialization as well as changes in our life style. Presently most of the waste generated is either disposed of in an open dump in developing countries or in landfills in the developed ones. Landfilling as well as open dumping requires lot of land mass and could also result in several environmental problems. Land application of urban/municipal solid waste (MSW) can be carried out as it is rich in organic matter and contains significant amount of recyclable plant nutrients. The presence of heavy metals and different toxics substances restricts its land use without processing. Vermicomposting of MSW, prior to land application may be a sustainable waste management option, as the vermicast obtained at the end of vermicomposting process is rich in plant nutrients and is devoid of pathogenic organism. Utilization of vermicast produced from urban/municipal solid waste in agriculture will facilitate in growth of countries economy by lowering the consumption of inorganic fertilizer and avoiding land degradation problem. Vermicomposting of urban/MSW can be an excellent practice, as it will be helpful in recycling valuable plant nutrients. This review deals with various aspects of vermicomposting of MSW.     

Comparison of energy produced from waste by removing its different components: A case study of the waste landfill in Tehran

In developing and populated cities such as Tehran, a massive amount of municipal solid waste (MSW), both wet and dry, is transferred to landfills daily. Combustion is one of the most common methods of using mixed waste energy from the past to the present. The Dulong formula is widely used to calculate the energy released from MSW combustion. According to the constituent components of Tehran MSW, removing food waste leads to an increase in energy potential, which will be a suitable condition for energy production. In this work, the energy derived from the combustion of mixed and separated dry MSW generated in Tehran was calculated using the experimental Dulong formula and tables in Integrated Solid Waste Management (Tchobanoglous et al. 1993, McGraw‐Hill). The Dulong formula indicates that the use of Tehran mixed MSW (without separating materials for recycling) as a fuel source yields 8,966.40 KJ/kg while the use of Tchobanoglous et al. (1993) tables can generate 8,236 kJ/kg. By removing food waste and recyclable materials, the potential of energy production changes to 22,047 kJ/kg using the Dulong formula and 16,207 kJ/kg and the Tchobanoglous et al. (1993) tables. It indicates increase by 1.46 times and 46%, respectively. Regarding the 200‐ton capacity of the Tehran waste incinerator, the Dulong formula indicated generation of 4,409 MJ/day energy, and the Tchobanoglous et al. table presents 3,241 MJ/day. Therefore, considering that Tehran generates more than 4,000 tons of reject waste daily, it can easily be converted to energy rather than landfilled. This can alleviate the problem of buying land and construction of landfills and leachate generation.     

Environmental and economic aspects of production and utilization of RDF as alternative fuel in cement plants: A case study of Metro Vancouver Waste Management

Municipal solid waste (MSW) disposal and management is one of the most significant challenges faced by urban communities around the world. Municipal solid waste management (MSWM) over the years has utilized many sophisticated technologies and smart strategies. Municipalities worldwide have pursued numerous initiatives to reduce the environmental burden of the MSW treatment strategies. One of the most beneficial MSWM strategies is the thermal treatment or energy recovery to obtain cleaner renewable energy from waste. Among many waste-to-energy strategies, refuse-derived fuel (RDF) is a solid recovered fuel that can be used as a substitute for conventional fossil fuel. The scope of this study is to investigate the feasibility of RDF production with MSW generated in Metro Vancouver, for co-processing in two cement kilns in the region. This study investigates environmental impacts and benefits and economic costs and profits of RDF production. In addition, RDF utilization as an alternative fuel in cement kilns has been assessed. Cement manufacturing has been selected as one of the most environmentally challenged industries and as a potential destination for RDF to replace a portion of conventional fossil fuels with less energy-intensive fuel. A comprehensive environmental assessment is conducted using a life cycle assessment (LCA) approach. In addition, cost–benefit analysis (CBA) has been carried out to study the economic factors. This research confirmed that RDF production and use in cement kilns can be environmentally and economically viable solution for Metro Vancouver.     

GC-MS法测定垃圾填埋场渗滤液中的有机污染物

采用GC-MS联用技术对深圳市两个垃圾填埋场（A和B）渗滤液中的有机污染物进行分析。垃圾场A是简易生活垃圾填埋场,垃圾场B是生活垃圾焚烧底渣填埋场。垃圾场A渗滤液中COD、TOC、NH3-N、NO3^--N等污染指标的浓度比垃圾场B渗滤液高一个数量级。两个垃圾填埋场渗滤液中分别检测出主要有机物72种和57种,其中含有大量难降解有机物,如酚类、胺类、杂环类物质。两个垃圾填埋场渗滤液中有机物组分的相对含量不同,渗滤液A中酚类物质含量最高,渗滤液B中有机物多为长链烷烃。     

Management of old landfills by utilizing forest and energy industry waste flows

The lack of landfill capacity, forthcoming EU waste disposal and landfill management legislation and the use of non-renewable and energy intensive natural resources for the end-treatment of old landfills increase pressures to develop new landfill management methods. This paper considers a method for the end-management of old landfills in Finland, which is based on the utilization of forest and paper industry waste flows, wastes from paper recycling (de-inking) and wastes from forest industry energy production. Fibre clay wastes from paper mills, de-inking sludges from de-inking of recovered waste paper and incineration ash from forest industry power plants serve to substitute the use of natural clay for the building of landfill structures for closed landfills. Arguably, this method is preferable to existing practices of natural clay use for landfill building, because it (1) substitutes non-renewable natural clay, (2) consumes less energy and generates less CO2 emissions than the use of natural clay, and (3) eliminates considerable amounts of wastes from paper production, paper consumption and from forest industry energy production. Some difficulties in the application of the method are considered and the waste flow utilization is incorporated into a local forest industry recycling network.     

A generic comparison of the airborne risks to human health from landfill and incinerator disposal of municipal solid waste

A comparison of the potential risks to human health from municipal solid waste (MSW) incineration and landfill on a generic basis is attempted. For this purpose a 'worst case' approach is adopted and a number of assumptions regarding the size and activities of each waste disposal method are made. The airborne pollutants measured for an incinerator are different from those for a landfill with or without gas collection. However, based on the available information it appears that as far as airborne pollution is concerned, landfill sites without gas collection pose a potentially higher generic risk to human health than MSW incinerators performing to Environmental Agency (UK) standards. This analysis cannot be used to replace specific evaluations for a particular incinerator or a landfill site because local conditions can have a very large impact on the magnitude of risks involved.     

Predictive model for areas with illegal landfills using logistic regression

The existence of illegal landfills is an environmental problem in most countries. However, research on this issue is scarce and limited by the availability and quality of data on the subject. Thus, most illegal landfill studies have only been conducted in a partial manner, focusing on geographical aspects or the causes of these landfills (lack of environmental awareness, inadequate waste management systems, and the role of local government). This research analyses a sample of 120 possible areas with illegal landfills in Andalusia using logistic regression in order to obtain a predictive model for the occurrence of these landfills, including both types of variables (geographical and behavioural) jointly. The results confirm that the variables that most influence the occurrence of illegal landfills are spatial (“Industrial Land”, “Plains” and “Rural Land”); whilst the variables that most reduce the likelihood of illegal landfills are those related to certain characteristics of the municipal waste management system and environmental awareness, such as “Availability of Recycling Facilities”, “Punitive Policies”, “Supervision” and “Awareness-raising Campaigns”. The model obtained shows that variables of very different nature and magnitude interact in the occurrence of illegal landfills, each of which contributes a series of features characteristic of its scale. It is advisable, therefore, to perform an analysis using a multi-scale approach in order to gain an overall understanding of the phenomenon.     

The Prospect of Municipal Waste Landfill Diversion Depends on Geographical Location

This study reports on experimentation with municipal and industrial solid waste in Brazil, on mutual inspection of municipal sanitation models in selected Spanish and Brazilian towns, and on observations of municipal solid waste (MSW) management models effective in Argentina, Great Britain, Sweden, and Germany. The diversity of management strategies inhibits technology transfer. Judging by the models inspected, Sweden and Germany appear to be best prepared for stricter European landfill diversion targets in the near future. Experimentation in Brazil has resulted in a proactive MSW management model based on divided collection, which achieves 80 percent landfill diversion. This result, surprisingly, meets and exceeds European diversion targets in a South American context. As the gap in strategy and target narrows between South America and Europe, both technology and management methods may gain intercontinental mobility and thus enhance commercial ties between the two markets in the specific branch of MSW management.     

Environmental assessment of different management options for individual waste fractions by means of life-cycle assessment modelling

Several alternatives exist for handling of individual waste fractions, including recycling, incineration and landfilling. From an environmental point of view, the latter is commonly considered as the least desirable option. Many studies based on life-cycle assessment (LCA) highlight the environmental benefits offered by incineration and especially by recycling. However, the landfilling option is often approached unjustly in these studies, maybe disregarding the remarkable technological improvements that landfills have undergone in the last decades in many parts of the world.This study, by means of LCA-modelling, aims at comparing the environmental performance of three major management options (landfilling, recycling and incineration or composting) for a number of individual waste fractions. The landfilling option is here approached comprehensively, accounting for all technical and environmental factors involved, including energy generation from landfill gas and storage of biogenic carbon. Leachate and gas emissions associated to each individual waste fraction have been estimated by means of a mathematical modelling. This approach towards landfilling emissions allows for a more precise quantification of the landfill impacts when comparing management options for selected waste fractions.Results from the life-cycle impact assessment (LCIA) show that the environmental performance estimated for landfilling with energy recovery of the fractions “organics” and “recyclable paper” is comparable with composting (for “organics”) and incineration (for “recyclable paper”). This however requires high degree of control over gas and leachate emissions, high gas collection efficiency and extensive gas utilization at the landfill. For the other waste fractions, recycling and incineration are favourable, although specific emissions of a variety of toxic compounds (VOCs, PAHs, NO_x, heavy metals, etc.) may significantly worsen their environmental performance.     

Greenhouse gas balance for composting operations

The greenhouse gas (GHG) impact of composting a range of potential feedstocks was evaluated through a review of the existing literature with a focus on methane (CH(4)) avoidance by composting and GHG emissions during composting. The primary carbon credits associated with composting are through CH(4) avoidance when feedstocks are composted instead of landfilled (municipal solid waste and biosolids) or lagooned (animal manures). Methane generation potential is given based on total volatile solids, expected volatile solids destruction, and CH(4) generation from lab and field incubations. For example, a facility that composts an equal mixture of manure, newsprint, and food waste could conserve the equivalent of 3.1 Mg CO(2) per 1 dry Mg of feedstocks composted if feedstocks were diverted from anaerobic storage lagoons and landfills with no gas collection mechanisms. The composting process is a source of GHG emissions from the use of electricity and fossil fuels and through GHG emissions during composting. Greenhouse gas emissions during composting are highest for high-nitrogen materials with high moisture contents. These debits are minimal in comparison to avoidance credits and can be further minimized through the use of higher carbon:nitrogen feedstock mixtures and lower-moisture-content mixtures. Compost end use has the potential to generate carbon credits through avoidance and sequestration of carbon; however, these are highly project specific and need to be quantified on an individual project basis.     

Environmental and economic assessment of combined biostabilization and landfill for municipal solid waste

Biostabilization can remove considerable amounts of moisture and degradable organic materials from municipal solid waste (MSW), and can therefore be an effective form of pretreatment prior to landfill. The environmental and economic impacts of two combined processes, active stage biostabilization + sanitary landfill (AL), and active and curing stage biostabilization + sanitary landfill (ACL), were compared with sanitary landfill (SL) for MSW with high moisture content. The results indicated that land requirement, leachate generation, and CH(4) emission in the ACL process decreased by 68.6%, 89.1%, and 87.6%, respectively, and the total cost was reduced by 24.1%, compared with SL. This implies that a combined biostabilization and landfill process can be an environmentally friendly and economically feasible alternative to landfill of raw MSW with high moisture content. Sensitivity analysis revealed that treatment capacity and construction costs of biostabilization and the oxidation factor of CH(4) significantly influenced the costs and benefits of the AL and ACL process at an extremely low land price. When the land price was greater than 100 USD m(-2), it became the dominating factor in determining the cost of treatment and disposal, and the total costs of ACL were reduced to less than 40% of those of SL.     

Assessing the demand of solid waste disposal in urban region by urban dynamics modelling in a GIS environment

The twentieth century saw a dramatic increase in the production of urban solid waste, reflecting unprecedented global levels of economic activity. Despite some efforts to reduce and recover the waste, disposal in landfills is still the most usual destination. However, landfill has become more difficult to implement because of its increasing cost, community opposition to landfill siting, and more restrictive environmental regulations regarding the siting and operation of landfills. Moreover, disposal in landfill is the waste destination method with the largest demand for land, while land is a resource whose availability has been decreasing in urban systems. Shortage of land for landfills is a problem frequently cited in the literature as a physical constraint. Nonetheless, the shortage of land for waste disposal has not been fully studied and, in particular, quantified. This paper presents a method to quantify the relationship between the demand and supply of suitable land for waste disposal over time using a geographic information system and modelling techniques. Based on projections of population growth, urban sprawl and waste generation the method can allow policy and decision-makers to measure the dimension of the problem of shortage of land into the future. The procedure can provide information to guide the design and schedule of programs to reduce and recover waste, and can potentially lead to a better use of the land resource. Porto Alegre City, Brazil was used as the case study to illustrate and analyse the approach. By testing different waste management scenarios, the results indicated that the demand for land for waste disposal overcomes the supply of suitable land for this use in the study area before the year 2050.     

Alternative treatments for the municipal solid waste and domestic sewage in Campinas,Brazil

The treatments of municipal solid waste (MSW) and the domestic sewage (DS) are critical issues of the current political and environment discussions. These concerns are due to the lack of dumping areas, the continuous increase of the population, and public health issues. The adequate treatment and management of MSW and DS can produce many benefits such as financial funds, heat and energy production, reduction of emissions and recuperation of water for reuse. Currently in Campinas MSW and DS are deposited in landfills or discharged into rivers and other sites. In the present study two scenarios are evaluated for the treatment of MSW and DS in Campinas: recycling with biological treatment and recycling with thermal treatment. The most suitable treatments for Campinas, based on the data from the present analysis and taking into consideration the local conditions, maximization of energy potential and environmental benefits, are incineration for the MSW and biological treatment for DS, both with energy recuperation. The main gains of this option are substantial environmental benefits, generated energy which can reach 18% of the total electrical energy consumed in Campinas while about 53% recuperation of the total amount of water treated for Campinas in 2010.     

Energy recovery from municipal solid waste in Nigeria and its economic and environmental implications

An assessment of potential biomass resources in Nigeria for the production of methane and power generation is presented in this paper. Nigeria, as an underdeveloped and populous country, needs an uninterrupted source of energy. The country's energy problems have crippled large sectors of the economy. The percentage of people connected to the national grid is 40%. These 40% experience electricity supply failure on average 10–12 hours daily. Energy generation from municipal solid waste (MSW) is an effective MSW management strategy. Yearly waste generation has increased from 6,471 gigagrams (Gg) in 1959 to 26,600 Gg in 2015. This amount is projected to reach 36,250 Gg per year by 2030. Methane emission for 2015 was 491 Gg, and it is projected to reach 669 Gg in 2030. These values translate to 3.48 × 10⁹ kilowatt hours (kWh) of electricity for 2015, with a projected 4.74 × 10⁹ kWh by 2030. The revenue to be derived from the electricity that is generated could have been US$365.04 × 10⁶ for 2015, and it is estimated that it will reach US$473.82 × 10⁶ by 2030. It was found that methane emissions from MSW increased with time, and capturing this gas for energy production will lead to a sustainable waste management.     

Reverse logistics in Malaysia: Investigating the effect of green product design and resource commitment

Reverse logistics and green product design are green supply chain management practices that are being implemented to demonstrate firm's commitment to environmental sustainability. The generation of waste from electrical and electronic equipments prompts the viability of product recovery to salvage invested material and energy. Selection of various reverse logistics product disposition options relies on products’ residual value and the accessibility of reusable content for re-entry in forward supply chain. This study explores the effect of green product design and resource commitment on reverse logistics product disposition by employing empirical analysis on 89 returned mail survey received from ISO14001 certified electrical and electronic manufacturing firms in Malaysia. The results indicated that design for disassembly is necessary to harvest valuable inventories from every product disposition options except of disposal whereas design for environment and commitment of resources have slight influence on repair and disposal activities. As the evidences show that green product design and reverse logistics product disposition are interrelated, firms ought to undertake environmentally proactive approaches to generate benefits from resources that are undeservingly discarded as landfill waste.