准好氧填埋场稳定化指标的室内模拟研究

准好氧填埋场是传统填埋场可持续发展的一个重要的方向,本文结合准好氧填埋场的室内模拟实验结果以及理论分析,提出了准好氧填埋场稳定化评价指标的四条选取原则,在模拟实验的基础上,从渗滤液性质、垃圾降解特性、填埋场地沉降三个方面建立了准好氧的评价指标体系,所包含的指标有:渗滤液COD、氨氮、TVS/TDS,固相垃圾BDM,场地沉降量.     

准好氧填埋场稳定化指标的室内模拟研究

准好氧填埋场是传统填埋场可持续发展的一个重要的方向，本文结合准好氧填埋场的室内模拟实验结果以及理论分析，提出了准好氧填埋场稳定化评价指标的四条选取原则，在模拟实验的基础上，从渗滤液性质、垃圾降解特性、填埋场地沉降三个方面建立了准好氧的评价指标体系，所包含的指标有：渗滤液COD、氨氮、TVS／TDS，固相垃圾BDM，场地沉降量。     

隔水帷幕技术在非正规垃圾填埋场治理中的工程应用

基于非正规垃圾填埋场的危害,并结合在非正规垃圾填埋场治理中常用的搬迁减量技术、好氧稳定化技术和原位封场治理技术的优缺点,提出在非正规垃圾填埋场治理中应用隔水帷幕技术,分析了应用该技术的基本条件是垃圾填埋场底部要有合适的防渗性较好的黏性土层,并通过工程应用详述了隔水帷幕技术在垃圾填埋场搬迁减量治理中的适用性。隔水帷幕技术可有效阻止垃圾填埋土和渗滤液对填埋场周边土层的污染,阻断填埋场周边地下水与渗滤液的水力联系,有效管控垃圾填埋土中污染物的扩散。     

老虎冲垃圾填埋场渗滤液的预处理研究

垃圾渗滤液的处理已成为国内外的热点课题,目前已建成的城市垃圾填埋场,大多数尚无完善的渗滤液处理设施,本研究的目的在于探索一种工艺指标先进、投资较低的垃圾填埋场渗滤液处理工艺。     

西北卫生填埋场渗滤液回灌系统研究

回灌技术是一种简单、低廉的渗滤液处理技术,可有效降低渗滤液中COD和氨氮的含量,加速填埋场内垃圾的降解,提高产甲烷速率和甲烷的产量,增大填埋场的沉降速率和总沉降幅度,缩短填埋场的维护期.回灌技术能够适应渗滤液水质水量的复杂变化,在我国西北地区有非常广阔的应用前景.同时,由于该技术在我国利用过程中尚缺乏成熟的工艺设计和运行经验,所以还有待进一步研究和实践.     

生活垃圾卫生填埋场清污分流与渗滤液收集系统的探讨

本文介绍了对生活垃圾卫生填埋场实行清污分流，以减少渗滤液；设置渗滤液收集系统，并对渗滤液进行处理，以防止垃圾填埋场渗滤液聚集、泄漏造成新的污染。     

生活垃圾卫生填埋汤清污分流与渗滤液收集系统的探讨

本文介绍了对生活垃圾卫生填埋场实行清污分流，以减少渗滤液；设置渗滤液收集系统，并对渗滤液进行处理，以防止垃圾填埋场渗滤液聚集、泄漏造成新的污染。     

生物质垃圾厌氧反应产出液与垃圾渗滤液混凝特性对比研究

本文通过实验,以固体FeCl3为混凝剂,以CODCr和色度去除率为衡量标准,分别测定了生物质垃圾厌氧反应产出液(以下统称产出液)与垃圾填埋场渗滤液(以下统称渗滤液)的絮凝剂最佳投加量、最佳反应PH值和最佳絮凝沉降时间,对比了产出液和渗滤液的混凝特性的差别.从实验中看出,在常规的化学混凝方法下,产出液的处理难度远大于渗滤液.     

强化准好氧填埋自然通风的原理及新途径研究

基于自然通风和准好氧填埋的基本理论，提出了几种强化准好氧填埋中自然通风效果的途径。实验结果表明，应用了吸风罩和风帽的改良型准好氧填埋可将填埋龄为2a的垃圾生物降解度（BDM）在200d左右的时间里由填埋初期的15．27％降到4．42％，衰减率为71．05％，大大缩短了垃圾降解的时间，加快了填埋场的稳定化进程。此外还发现，风速对改良型准好氧填埋方法的进风量影响显著，风速越大，甲烷的排放浓度降低幅度越大。     

垃圾土变形特性及防渗膜受力的试验研究

垃圾填埋场中垃圾土的降解是垃圾填埋场沉降的主要原因,而垃圾填埋场的沉降对HPDE衬垫膜的受力和工作状态有显著的影响,HPDE衬垫膜的设计需要考虑垃圾填埋场沉降的作用,文章通过垃圾土中有机物的降解试验和垃圾土柱沉降试验,推求了考虑垃圾土压缩和降解的变形计算方法,进行了垃圾填埋场的离心模型试验,探讨了垃圾填埋场中垃圾体的变形分布规律和衬垫膜的受力特征,对衬垫膜的设计计算方法进行了研究。     

Performance of North American Bioreactor Landfills. I: Leachate Hydrology and Waste Settlement

An assessment of state-of-the-practice at five full-scale North American landfills operating as bioreactors is presented in this two-paper set. This paper focuses on effectiveness of liners and leachate collection systems, leachate generation rates, leachate recirculation practices and rates, effectiveness in moistening the waste, and settlement of the waste over time. Except in one case, the liner and leachate collection systems at the bioreactor landfills were similar to those used for landfills operated conventionally. Leachate generation rates increased approximately linearly with recirculation rate, but in all cases, the leachate generation rate was <300?L/m2?year. Leachate depths generally were maintained within regulatory requirements, even with the highest recirculation rates. Leakage rates from liners at bioreactor landfills, including alternative liner designs employing geosynthetic clay liners, are comparable to leakage rates from conventional landfills. Thus, based on the information gathered in this study, additional requirements or features for liners or leachate collection systems are not warranted for bioreactor landfills. Diminishing capacity of horizontal recirculation trenches is common. Experience at one landfill suggests that small doses at high frequency under substantial injection pressure can deter loss of trench capacity. Only those landfills that were aggressive in recirculation had achieved water contents near the field capacity. Increasing the amount of liquid that is added may be required to achieve field capacity at some landfills, particularly if a final cover is placed soon after waste grades are reached. The rate of time-dependent waste settlement attributed to biodegradation is about 1.6 times larger in bioreactor landfills than in conventional landfills, and increases as the recirculation dosage increases.     

Secondary Compression of Municipal Solid Wastes and a Compression Model for Predicting Settlement of Municipal Solid Waste Landfills

The estimation of the capacity and settlement of landfills is critical to successful site operation and future development of a landfill. This paper reports the results of a study on biodegradation behavior and the compression of municipal solid wastes. An experimental apparatus was developed which had a temperature-control system, a leachate recycling system, a loading system, and a gas and liquid collection system. Experiments were performed both with and without optimal biodegradation for comparative purposes. Test results indicated that settlement resulting from creep was relatively insignificant when the biodegradation process was inhibited. Compression due to decomposition under optimal biodegradation conditions was found to be much larger than compression associated with creep. The biodegradation process was significantly influenced by the operational temperature. A one-dimensional model is proposed for calculating settlement and estimating the capacity of the landfill under relatively optimal biodegradation conditions. The model was developed to accommodate the calculation of settlement in landfills when a multistep filling procedure was used. The calculation method is relatively simple and convenient for design purposes. Simulations of the physical processes showed that enhancing solid waste biodegradation during the filling stage can considerably increase the capacity of the landfill and reduce postclosure settlements.     

垃圾填埋场渗沥液处理技术发展趋势

综述我国垃圾渗沥液的特性、处理技术的发展和应用情况,并对存在的问题、发展对策进行了分析。     

垃圾填埋场渗沥液处理技术发展趋势

综述我国垃圾渗沥液的特性、处理技术的发展和应用情况，并对存在的问题、发展对策进行了分析。     

One-Dimensional Gas Flow Model for Horizontal Gas Collection Systems at Municipal Solid Waste Landfills

Extraction of biogas from horizontal layers above, below, and within municipal solid waste landfills is becoming more commonplace. A steady-state one-dimensional analytical landfill gas model was developed to assist in the assessment and design of such collection systems. The model simulates the distribution of gas pressure within a layer of landfill waste under a variety of operating conditions that include upper and lower boundaries specified at given fluxes or pressures. The model can be used to predict where maximum pressures will build up within the landfill and what vacuum pressures must be applied to achieve specific gas collection efficiency in a horizontal collection layer. The utility of the model was illustrated for several scenarios of interest. In the absence of gas collection from a landfill’s leachate collection system, considerable gas pressures can build up at the bottom of the landfill. The design of leachate collection systems for landfill gas removal should be considered from the outset. An evaluation of the parameters that impact vacuum requirements—waste depth, gas generation rate, and waste permeability—suggests that it may not be feasible to rely solely upon the leachate collection system for the removal of landfill gas. The model was thus used to illustrate cases where a horizontal collection layer underneath the landfill cap is used in conjunction with gas extraction from the bottom of the landfill. Several recommendations are proposed to improve the gas collection efficiencies for landfills utilizing horizontal gas collection layers.     

Parameter Evaluation and Performance Comparison of MSW Settlement Prediction Models in Various Landfill Types

Estimation of settlement for municipal solid waste (MSW) landfills is critical to the successful site operation and maintenance as well as to the future development of the sites. In this paper, the six existing settlement prediction models are analyzed according to the three landfill types. 15 MSW landfill sites are classified into three categories, Types I, II, and III depending on their settlement activity levels and fill age. Measured settlement data of each landfill site are plotted as a strain curve on a logarithmic time scale, and the slope of the curve is used to determine a settlement activity level. First, the parameters of each prediction model are evaluated to determine their typical values for each type of the landfills. The results will serve as a basis for engineers to determine if their calculated model parameters are within the typical ranges. Second, each model’s performance of predicting settlement for the landfill sites is analyzed against the measured settlement data to compare the model’s applicability according to the landfill types. The results recommend specific prediction models to be used in a certain landfill type(s).     

Pilot-Scale Simulation of Landfill Bioreactor and Controlled Dumping of Fresh and Partially Stabilized Municipal Solid Waste in a Tropical Developing Country

Four pilot-scale lysimeters were used to study the benefits of landfill operation with and without leachate recirculation in tropical weather conditions. Young and old landfills were simulated by filling lysimeters with a segregated fraction of fresh municipal solid waste (MSW) and MSW mined from an open dump site, respectively, and periodically monitoring leachate quantity and quality and biogas quality. For each substrate, one lysimeter was operated as a bioreactor with leachate recirculation and another lysimeter was operated as a controlled dump, for a period of 10 months. Densities between 652 and 825??kg/m3 could be achieved with fresh and mined MSW. Despite such compaction during waste placement, bioreactor technology helps in leachate management, especially in the case of the young landfill lysimeter operated in tropical weather. The benefits of leachate recirculation in the young landfill lysimeter were evident from the significant decrease in chemical oxygen demand (COD) (86%), biochemical oxygen demand (BOD) (82%), dissolved organic carbon (DOC) (85%), and volatile solids (75%) in leachates. However, ammonia nitrogen (amm-N) and chlorides in the leachates accumulated in bioreactor landfills. Operating an old landfill lysimeter as a bioreactor seemed to have no exceptional advantage in the context of leachate management, although leachate recirculation enhanced the methane potential of both fresh and mined MSW.     

Operation and Performance of Horizontal Wells for Leachate Control in a Waste Landfill

This paper presents data on gas and leachate flow rates and leachate levels obtained during a 600?day pumping trial on three retrofitted horizontal wells in a domestic waste landfill at Rainham, United Kingdom. The changes in gas and leachate flow rate with time and atmospheric pressure, and the interaction between the two flows, are discussed. The spatial variability of the response of the leachate levels within the landfill is explored with reference to the anisotropy and heterogeneity of the permeability of the waste. It is shown that horizontal wells can be an effective means of controlling leachate heads near the base of a landfill, and that leachate levels must be measured using piezometers with a discrete response zone rather than fully screened observation wells if meaningful results are to be obtained. It is argued that the large amounts of gas pumped from the nominally saturated zone of the landfill must have come from the ongoing degradation of the waste within the zone of influence of the well.     

垃圾渗滤液处理技术研究进展

介绍了渗滤液产生来源和特点，指出垃圾渗滤液是一种非常复杂的、难以生物处理的污水，并对垃圾渗滤液物理化学处理、生物处理及土地处理法进行了探讨，重点介绍了渗滤液的土地处理，包括渗滤液回灌、人工湿地法和渗滤液矿化垃圾生物反应床处理技术，指出了土地法处理垃圾渗滤液无论在技术上还是经济上比较是可行的。     

垃圾渗滤液处理技术研究进展

介绍了渗滤液产生来源和特点,指出垃圾渗滤液是一种非常复杂的、难以生物处理的污水,并对垃圾渗滤液物理化学处理、生物处理及土地处理法进行了探讨,重点介绍了渗滤液的土地处理,包括渗滤液回灌、人工湿地法和渗滤液矿化垃圾生物反应床处理技术,指出了土地法处理垃圾渗滤液无论在技术上还是经济上比较是可行的。