陈垃圾沉降分析方法及工程应用

已填垃圾的沉降分析是正确评估填埋场服务年限和合理确定填埋厚度的重要依据,根据陈垃圾的形成机制、沉降模型、计算方法以及及有关参数,并结合工程实例对填埋过程中的垃圾沉降发展过程进行了研究,确定了陈垃圾土的沉降特性。     

城市生活垃圾填埋场垃圾-土壤-植物中汞含量的分布特征

在贵阳和武汉市的4座城市生活垃圾填埋场,研究了其中的生活垃圾、土壤和植物中的汞含量分布特征。结果显示,城市生活垃圾的汞含量分布极不均匀,浓度为0.170~46.222 mg.kg-1,几何均值0.574 mg.kg-1,一半以上的样品汞含量低于0.5 mg.kg-1,个别含量异常偏高,可能是被混入的含汞废弃产品污染了,而各个填埋场的垃圾汞含量几何均值相差不大。不同垃圾填埋场覆盖土壤的汞含量差异显著,反映了填埋场所在区域的土壤背景值以及垃圾填埋活动对覆盖土壤的污染程度,有时覆盖土壤的汞含量超过区域土壤背景值的2~23倍。填埋场附近的农田土壤存在一定的汞污染迹象。填埋场生长的植物因生活习性的不同汞含量分布特征也不同,无喙齿冠草为叶>根>茎,狗牙根和硬质早熟禾为地下部分>地上部分。随着填埋场运行时间的增长,附近生长的苔藓汞含量不断升高,封闭填埋场种植的玉米果实有一部分汞含量超过了食用标准,这些都说明填埋场的运行会给周围的生态环境带来一定的汞污染风险。     

生物反应器填埋场的发展及应用研究

缩短垃圾稳定化时间,并有效地收集和处理渗滤液及填埋气体,是促使传统卫生填埋法向生物反应器填埋场发展的主要因素。生物反应器填埋场通过回灌渗滤液等控制手段,改善填埋场内部微生化环境,加速填埋场稳定化进程。生物反应器填埋场的关键在于渗滤液收集系统、防渗系统、气体收集系统和渗滤液回灌系统。一些在运行的全规模生物反应器填埋场证明了这种操作方式能加快垃圾降解和填埋气体的产生,减少渗滤液处理量。然而还有一些经济和技术上的不确定性,包括持久有效性、压实度和氧化-还原环境等因素都需要进一步研究。     

填埋垃圾和渗滤液中CH4氧化菌的丰度研究

应用实时荧光定量聚合酶链式反应(Real-Time Quantitative Polymerase Chain Reaction,简称实时荧光定量PCR)技术对填埋场垃圾和渗滤液中CH₄氧化菌的pmoA基因进行定量分析. 结果表明:实时荧光定量PCR技术可用于渗滤液和垃圾中CH₄氧化菌的定量分析. 对于厌氧和准好氧填埋,初期渗滤液中CH₄氧化菌的数量均高于稳定期;准好氧填埋体渗滤液中CH₄氧化菌的数量均高于厌氧填埋体. 准好氧填埋垃圾中CH₄氧化菌的数量随着填埋龄的增加呈先增加后降低的趋势,并在填埋后的9个月左右达到最大值,与准好氧填埋体CH₄产生的规律相似. 同时,准好氧填埋垃圾中CH₄氧化菌的数量随着距导气管距离的增加而降低,但不同填埋时期的变幅不同,与准好氧填埋体O₂和CH₄的迁移规律有关. 此外,对渗滤液和垃圾样品的研究表明,准好氧填埋体垃圾填埋层内部存在大量的CH₄氧化菌,具有显著的CH₄氧化能力.      

填埋场垃圾堆体斜面压实工程试验研究

通过现场工程试验对填埋垃圾堆体斜面压实效果进行了影响因素的研究．试验证明：在垃圾填埋作业过程中，压实机械对填埋垃圾堆体斜面压实的效果受垃圾堆体斜面坡度、垃圾堆体构造层厚度、压实机械行程次数以及压实机械的行驶方向等因素影响显著．实验结果表明：为取得最佳的垃圾堆体斜面压实效果，斜面最佳坡度在1：5～1：4之间，最佳垃圾摊铺厚度在0．6m～0．7m之间，最佳机械行程次数为3次，压实机械的行驶方向为坡下向坡上．     

垃圾填埋场抽气竖井周边气体运移规律研究

通过建立填埋场抽气竖井周边气体轴对称稳态运移模型,分析了单层和分层垃圾体中气压力分布,并提出“降压百分比”的概念用于判定抽气影响范围,研究了垃圾产气率、气体渗透率、覆盖层厚度、覆盖层气体渗透率、抽气井深度和抽气负压对抽气影响范围和抽气量的影响,获得了竖井深度和井间距的确定方法.分析结果表明,抽气井的降压作用明显,抽气井深度和抽气负压越大,则抽气影响范围和抽气量越大.覆盖层厚度增加或其渗透率降低有助于扩大抽气影响范围和提高抽气量.抽气影响范围随气体渗透率的增加而增大,但随垃圾产气率的增加而减少;抽气量则随气体渗透率和产气率的增大而增加.抽气井深度是控制抽气影响范围的关键参数,建议竖井深度取垃圾填埋厚度的65％～75％,井间距取1.5～2.5倍竖井深度.     

填埋场垃圾堆体平面压实工程试验研究

原生垃圾密度很小，为提高填埋垃圾堆体密实度、延长填埋场使用寿命，对填埋垃圾进行压实处理很重要。本文通过现场工程试验对影咱填埋垃圾堆体平面压实效果的主要因素进行了系统研究。实验结果表明：为取得最佳的垃圾堆体平面压实效果，最佳垃圾摊铺厚度在0.5m—0.7m之间，最佳机械行程次数为3次，增加碾压次数有利于提高垃圾堆体密实度，垃圾最佳含水率在30％——50％之间。     

Life cycle assessment as a decision support tool for landfill gas-to energy projects

The greenhouse gas (GHG) emissions from MSW landfill, and control methods to eliminate or minimize these impacts including energy recovery from landfill gas (LFG) of MSW landfill in Thailand have been evaluated. Life Cycle Assessment (LCA) is used as the analytical tool to evaluate the environmental consequences of landfilling holistically. The economic implications of the control methods are also briefly assessed. The results show that in terms of GHG emissions as well as in terms of economics, it is more advantageous to have a large centralized landfill and produce electricity from the LFG rather than having several small, localized landfills despite significantly lower transportation requirement for the latter case. Sensitivity analysis revealed that the global warming potential was sensitive to gas collection efficiency as well as methane oxidation rate in the landfill. This study shows the utility of a life cycle approach for evaluating LFG-to-energy (LFGTE) projects.     

基于城市固体废弃物的生物炭制备及其在垃圾填埋场和土壤改良中的应用研究进展

近年来,以城市固废为原料制备生物炭为其资源化利用开辟了新思路,但在制备方式、影响因素及主要应用领域仍缺乏有效阐述。介绍了生物炭的制备方式,系统分析了城市固废原料、生产工艺对生物炭产率和性质等影响;在此基础上,概述了生物炭在垃圾填埋场治理修复(渗滤液处理、垃圾填埋场覆盖、可渗透反应墙材料)和土壤改良(理化性质、营养环境)的应用现状。结果表明:1) 热解和水热碳化是城市固废制备生物炭的常用方式,其形成的生物炭具有较大的比表面积、孔隙率及更丰富的组分,对污染物质(如I-、Cu2+等)具有较强的吸附能力;2) 城市固废自身特性及生产工艺都会对所得生物炭的性质产生影响;3) 以特定城市固废生产的生物炭可用于垃圾填埋场修复和土壤改良,对填埋场造成的土壤、大气、地下水污染均具有良好的处理效果,也能充分提高土壤养分的有效性。该成果可为基于城市固废的生物炭生产及环境治理修复相关研究提供参考。     

Minimizing N_20 fluxes from full-scale municipal solid waste landfill with properly selected cover soil

Municipal solid waste landfills emit nitrous oxide(N_2O)gas.Assuming that the soil cover is the primary N_2O source from landfills, this study tested,during a four-year project,the hypothesis that the proper use of chosen soils with fine texture minimizes N_2O emissions.A full-scale sanitary landfill,a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb,at the Hangzhou Tianziling landfill in Hangzhou City were the test sites.The N_2O emission rates from all test sites were considerably lower than those reported in the published reports.Specifically,the N_2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil.The effects of leachate recirculation and irrigation were minimal.Properly chosen cover soils applied to the landfills reduced N_2O flux.     

Control of hydrogen sulfide emissions using autotrophic denitrification landfill biocovers: engineering applications

Hydrogen sulfide (H₂S) emitted from construction and demolition waste landfills has received increasing attention. Besides its unpleasant odor, longterm exposure to a very low concentration of H₂S can cause a public health issue. In the case of construction and demolition (C&D) waste landfills, where gas collection systems are not normally required, the generated H₂S is typically not controlled and the number of treatment processes to control H₂S emissions in situ is limited. An attractive alternative may be to use chemically or biologically active landfill covers. A few studies using various types of cover materials to attenuate H₂S emissions demonstrated that H₂S emissions can be effectively reduced. In this study, therefore, the costs and benefits of H₂S-control cover systems including compost, soil amended with lime, fine concrete, and autotrophic denitrification were evaluated. Based on a case-study landfill area of 0.04 km², the estimated H₂S emissions of 80900 kg over the 15-year period and costs of active cover system components (ammonium nitrate fertilizer for autotrophic denitrification cover, lime, fine concrete, and compost), ammonium nitrate fertilizer is the most cost effective, followed by hydrated lime, fine concrete, and yard waste compost. Fine concrete and yard waste compost covers are expensive measures to control H₂S emissions because of the large amount of materials needed to create a cover. Controlling H₂S emissions using fine concrete and compost is less expensive at landfills that provide on-site concrete recovery and composting facilities; however, ammonium nitrate fertilizer or hydrated lime would still be more cost effective applications.     

Comparison between controlled landfill reactor and conditioned landfill bioreactor

Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste (MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature decomposing MSW. The results of waste biodegradation were compared with that of the leachate-recirculated landfill simulator and conservative sanitary landfill simulator. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown. An obvious enhancement of effective disposal from conservative sanitary landfill (CSL) simulator, to the leachate-recirculated landfill (LRL) simulator and to the conditioned bioreactor landfill(CBL) simulator would be noted, through displaying the compared results of solid waste settlement, heavy, metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio.     

固废填埋长期环境安全和寿命预测研究综述

我国固废填埋场数量多、运行水平低、设施老化快、预期寿命偏短且寿命到期后老化严重.与此相对,固废填埋场寿命相关研究却存在关注度较少、研究方向不明确、研究内容不系统等问题.本文综述了通用工程领域寿命预测的基本概念及其发展历程,分门别类地梳理工程寿命预测的主要研究对象和研究方法;在此基础上,结合固体废物填埋工程和实际特征,系...     

生活垃圾填埋场春夏季CH4释放及影响因素

采用静态箱法监测了2个生活垃圾填埋场春、夏季及昼夜的CH₄释放通量,并分析了影响CH₄释放的相关因素. 结果表明:填埋气体(LFG)主动收集对填埋场CH₄释放的影响显著. 在填埋龄相近的条件(4.0～4.5年)下,无LFG主动收集的填埋场春、夏季CH₄的释放通量(以CH₄计)平均值〔(541±1　005) mg/(m2·h)〕比有LFG主动收集的填埋场提高4.4倍. 在有LFG主动收集的填埋场内,填埋龄为1.0～1.5年的非渗滤液灌溉区的CH₄释放通量均值〔(324±847)mg/(m2·h)〕为灌溉区的10.0倍左右. 在有LFG主动收集的填埋场内,CH₄释放通量与各环境因子间无显著相关;而在无LFG主动收集的填埋场内,CH₄释放通量分别与覆土温度和气温呈显著正相关,与大气压强呈显著负相关.相关性分析结果表明,CH₄释放通量与填埋场覆土中含水率,w(有机碳)和w(总氮)呈显著正相关.      

武进市夹山垃圾卫生填埋场的水环境影响与控制

卫生填埋是目前及今后相当长的时期内我国城市生活垃圾（MSW）处理的主要方式。但按我国卫生填埋技术、污染控制标准，目前国内尚没有垃圾填埋场能全部达到要求，多为准卫生填埋场。其运行后，对周围的大气及水体、土壤等环境将产生一定影响（污染）。本文以武进市夹山垃圾卫生填埋场为例，着重对填埋场运行后垃圾渗滤液等对周围地表、地下水环境的影响进行了分析评价，并提出了相关控制对策。     

Minimizing N2O fluxes from full-scale municipal solid waste landfill with properly selected cover soil

Municipal solid waste landfills emit nitrous oxide （N2O） gas. Assuming that the soil cover is the primary N2O source from landfills, this study tested, during a four-year project, the hypothesis that the proper use of chosen soils with fine texture minimizes N2O emissions. A full-scale sanitary landfill, a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb, at the Hangzhou Tianziling landfill in Hangzhou City were the test sites. The N2O emission rates from all test sites were considerably lower than those reported in the published reports. Specifically, the N2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil. The effects of leachate recirculation and irrigation were minimal. Properly chosen cover soils applied to the landfills reduced N2O flux.     

压力对填埋垃圾产甲烷的影响研究

压实作用被认为是影响填埋垃圾降解过程的一个重要因素,实验通过自制的压缩降解模拟填埋反应器装置,研究了阶梯增加式压力21k Pa→42 k Pa→84 k Pa(分别在垃圾填埋后的第75、103和131 d时施加)对填埋垃圾产甲烷这一资源化重要阶段的影响,包括产气特性、渗滤液性质及固体沉降等的变化.21 k Pa和42 k Pa分别恒定了4周,垃圾最后在84 k Pa恒定压力下降解,实验总共持续了170 d.结果表明,在初始21k Pa的压力作用下,由于接种物跟垃圾接触面积的增大,甲烷日产量从第75 d的1.85 L·d-1增加到了第76 d的2.95 L·d-1,产甲烷速率提高了59.82%,42 k Pa和84 k Pa时均有所增加,但增加程度均不明显.压力还使砾石层上部积留了一定水位高度的渗滤液,渗滤液的COD和含氮量在压力作用下都有了暂时的升高.压实作用还令垃圾体产生了较大的沉降,但压力进一步增大并没有使垃圾继续发生较多的沉降.实验结果有助于更好地了解压力对填埋垃圾降解过程的影响.     

北京市6座垃圾填埋场地下水环境质量的模糊评价

以接纳北京市城八区生活垃圾的6座填埋场的渗滤液和地下水环境质量为研究对象,2006年对6座垃圾填埋场的渗滤液性质以及丰水期、平水期和枯水期的地下水质进行监测分析和模糊评价.除北神树垃圾填埋场渗滤液中的BODs和悬浮物含量2项指标合格外,所有垃圾填埋场渗滤液中的COD、铵态氮和粪大肠菌群指标均超过了GB 16889-1997三级标准.其中铵态氮和粪大肠菌群超标最为严重.应用模糊数学进行综合评价的结果表明,6座垃圾填埋场枯水期、丰水期和平水期的地下水质均不合格,且综合评价结果为很差的占95%以上.地下水中的主要污染物是总硬度,其次为大肠菌群.     

稳定化飞灰填埋处置环境中二噁英溶出影响因素研究综述

垃圾焚烧飞灰是一种富集二噁英类污染物的危险废物。随着我国垃圾填埋场从原生垃圾填埋向焚烧残渣(主要为稳定化飞灰)填埋转型,稳定化飞灰中的二噁英溶出将是未来填埋场渗滤液污染的重要来源之一,溶出过程受填埋环境中DOM(DOC、DHM、HA等)、pH值、表面活性剂、非有机溶剂和微生物作用等多种因素的共同影响。目前对填埋稳定化飞灰中二噁英的溶出风险问题尚缺乏全面认识。综述了国内外关于垃圾焚烧飞灰中二噁英的典型含量和分布特征,重点总结了稳定化飞灰填埋处置环境中影响二噁英溶出的主要因素及影响规律,分析了二噁英的溶出风险性。指出应从飞灰中二噁英产生的源头、过程以及最终处置等方面加强对二噁英的减量化,并开展关于共填埋处置环境或多因素交互影响条件下二噁英溶出和转化机制以及风险评估方法学的研究。     

Discrete event simulation to aid decision-making and mitigation in solid waste management

This article aims to evaluate municipal solid waste (MSW) management schemes in order to promote sustainability and eco-efficiency, core elements in global mitigation strategies in both public and private policies. A discrete event simulation (DES) approach was used to integrate the economic, environmental, and social aspects related to aseptic carton packages (ACP) in Itajuba, Brazil. The simulated scenarios consider three alternatives for disposing ACP: landfills, recycling, and incineration with energy recovery. According to our findings, incineration alternatives are preferred from an eco-efficiency perspective, given the potential greenhouse gas (GHG) emissions reductions and due to the possibility of energy recover, which reinforces the contribution of this technology to promote sustainability as largely found in the international literature. Given the context of MSW management in Brazil, this represents a significant opportunity to increase the effectiveness of mitigation strategies adopted in the country. Taking into account that this is by far the least applied technology, the authors strongly advocate that global strategies for mitigation consider different approaches to integrate carbon dioxide (CO₂) emission reductions related to the entire MSW management system and its alternatives, thus advancing from a waste disposal-oriented system to a life cycle–oriented system.