垃圾填埋气中微量挥发性有机物的净化技术

垃圾填埋气中存在的多种微量挥发性有机物(VOCS),既造成二次污染,影响了人类健康;又对填埋气的回收利用产生了不利影响。本文综述了几种VOCS常规净化技术的基本原理、优势及限制,介绍了几种新兴技术,并预期有效的联合工艺是净化填埋气中微量VOCs的研究方向。     

城市垃圾渗滤液场内循环处理的探讨

本文对城市垃圾渗滤液的产生量、水质特征及其影响因素进行了分析，介绍了当前国内外垃圾渗滤水场内循环处理的两大研究流派-以欧美国家为主的生物反应器填埋技术和以日本为主的循环式准好氧填埋技术。根据我国城市垃圾有机物含量高的特点，提出了适合我国国情的、将准好氧填埋技术与生物反应器填埋技术特点相结合的城市垃圾填埋场渗波液场内循环处理的设计思路。     

垃圾填埋气收集利用研究进展

城市生活垃圾填埋过程中伴随产生大量填埋气,造成的环境影响不容忽视,填埋气中的CH4具有很高热值,是可利用的再生能源。对我国垃圾填埋气的特点、常见收集方式、焚烧发电利用现状进行了综述和分析,并探讨了未来的发展方向。     

垃圾填埋场水力学特性的研究进展

本文对填埋场渗滤液产生和运移的水力学特性的研究成果进行了总结，建立在填埋垃圾均质各向同性假设基础上的渗滤液运移模型不能满足日后生物反应器填埋场渗滤液回灌系统的设计和操作运行需要，基于填埋垃圾非均质各向异性的填埋场水力学特性将是今后研究的重点。     

国外环保信息三则

欧洲有机垃圾管理在欧洲，对有机垃圾的管理已经成为环境政策中的一个主要组成部分。为将城市固体废弃物中的有机物填埋造成的危害减到最小，欧盟出台了有机垃圾填埋法令。该法令制定了减少有机垃圾填埋量的目标，目标规定：到２００６年有机垃圾填埋减量率要达到２５％，到２０１３年要达到５０％，到２０２０年要达到６５％。欧盟成员国每年大约产生１．８亿吨城市固体废弃物（不含商业垃圾），各国的人均年垃圾排放量在４００～６００公斤之间。德国、法国、意大利和英国城市固体废弃物产生量占欧盟各成员国的７２％，在这四个国家的有机…     

固体废弃物资源化的新途径—CBS系统

城市固体生活垃圾和污泥的处理一直是城市建设和环境保护中的一大难题。如今,在中国大多数城市的垃圾和污泥都是采用填埋的方式进行处理。填埋过程所产生的臭气、渗淋液、苍蝇以及致病菌不断地侵害着我们的空气、土壤和水源。填埋需要大量的土地,当填埋场地饱和后还要向其...     

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。     

数字

据统计,全国1／4的城市已基本没有垃圾填埋堆放场地。垃圾围城问题虽早就提出过,但一直没得到有效解决,很多城市都在垃圾处理问题上走了弯路,当时只是简单堆放、填埋．给日后发展埋下了隐患。堆积如山的垃圾如一颗巨型“炸弹”,     

生活垃圾填埋产沼的提取净化利用

垃圾填埋是目前我国各城市广为采用的垃圾处理方式，但垃圾填埋产沼以后对沼气的回收利用却不被人们所熟知和重视。由此造成了对可开发利用的二次能源的极大浪费，而沼气对周围环境也造成了严重的污染并对大气臭氧层造成了破坏。本文阐述了垃圾填埋产沼回收的必要性和经济性，对垃圾填埋产沼提取利用、制取汽车压缩气的可行性及工艺流程进行了分析和介绍。     

我国城市生活垃圾处理标准体系日趋完善

一、垃圾处理标准备受关注目前,与垃圾从收集到处理过程中的各环节技术要求相对应的工程技术标准有《生活垃圾分类收集方法与评价标准》;《生活垃圾转运站设计规范》;《生活垃圾堆肥处理工程技术规范》;《生活垃圾卫生填埋工程技术规范》以及《生活垃圾焚烧处理工程技术规范》。这些标准作为通用技术标准,在转运站的选址,规模、建设和环境、分选设备、中转设备和设施;在堆肥原料、堆肥工艺、环境保护、堆肥厂的设计、施工验收;在焚烧厂的总体工艺,生活垃圾产量与特性分析,垃圾接收、储存、运输、焚烧系统、烟气净化系统、垃圾热能利用系统、…     

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.     

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.     

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.     

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.     

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.     

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。     

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。     

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.     

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。     

Options for management of municipal solid waste in New York City: a preliminary comparison of health risks and policy implications

Landfill disposal and waste-to-energy (WTE) incineration remain the two principal options for managing municipal solid waste (MSW). One critical determinant of the acceptability of these options is the different health risks associated with each. In this analysis relying on published data and exposure modeling, we have performed health risk assessments for landfill disposal versus WTE treatment options for the management of New York City's MSW. These are based on the realistic scenario of using a waste transfer station (WTS) in Brooklyn and then transporting the untreated MSW by truck to a landfill in Pennsylvania or using a WTE facility in Brooklyn and then transporting the resultant ash by truck to a landfill in Pennsylvania. The overall results indicate that the individual cancer risks for both options would be considered generally acceptable, although the risk from landfilling is approximately 5 times greater than from WTE treatment; the individual non-cancer health risks for both options would be considered generally unacceptable, although once again the risk from landfilling is approximately 5 times greater than from WTE treatment. If one considers only the population in Brooklyn that would be directly affected by the siting of either a WTS or a WTE facility in their immediate neighborhood, individual cancer and non-cancer health risks for both options would be considered generally acceptable, but risks for the former remain considerably higher than for the latter. These results should be considered preliminary due to several limitations of this study such as: consideration of risks only from inhalation exposures; assumption that only volume and not composition of the waste stream is altered by WTE treatment; reliance on data from the literature rather than actual measurements of the sites considered, assuming comparability of the sites. However, the results of studies such as this, in conjunction with ecological, socioeconomic and equity considerations, should prove useful to environmental managers, regulators, policy makers, community representatives and other stakeholders in making sound and acceptable decisions regarding the optimal handling of MSW.