Landfill mining and waste characterization: a strategy for remediation of contaminated areas

This article describes landfill-mining tests, including excavation, screening, and fraction characterization, carried out in the Msalycke and Gladsax landfills for municipal solid waste (MSW) in Sweden. The excavated waste in these two sites was 17–22 and 23–25 years old, respectively. The main part of Msalycke was unaffected by degradation, and during excavations no substantial amount of biogas was detected. After screening, three size fractions were obtained: <18mm, 18–50mm, and >50mm. Soil amendment and anaerobic digestion with energy extraction are suggested for the first and second fraction, respectively. Incineration with energy recovery is possible with the third fraction after any coarse (inert) material is removed, and construction/demolition waste can easily be recycled provided that it is not contaminated by hazardous material. Excavated waste taken from different depths was also analysed and compared in relation to composition, calorific value, and leachate constituents.     

Comparing the performance of landfill liner systems

 Some minimum design requirements for landfill liner systems were compared, and the performance of several Japanese liner systems was investigated by two-dimensional (2D) contaminant transport analysis. We demonstrate that (1) the performance of each system specified by the Japanese Ministry of Health and Welfare (at present the Ministry of Health, Labor, and Welfare) varies, (2) the adsorption characteristics of the mineral barrier has a significant effect on the contaminant transport process, and (3) a geomembrane layer in the barrier system is very efficient in reducing the peak concentration of contaminants in the groundwater beneath a landfill even if the geomembrane has a number of defects. Under the conditions considered, the analysis results show that a liner system without a geomembrane layer should be avoided. Received: July 4, 2001 / Accepted: March 26, 2002     

The UK Landfill Tax: an analysis of its contribution to sustainable waste management

The UK Government in October 1996 introduced a Landfill Tax to ensure that landfill waste disposal is properly priced so as to reflect its environmental cost and to help promote a more sustainable approach to waste management in which less waste is produced, reused or recycled. The UK Customs and Excise have recently reviewed the tax and the report indicates that there has been a modest reduction in waste going to landfill by industry but not households. It is submitted that for there to be a significant move towards a more sustainable approach to waste management to meet the targets set in the National Strategy the tax should be higher and the money raised by the tax should be invested to make alternatives to landfill cheaper and more readily available. It is also submitted that the Tax Credit Scheme, introduced as a means of enabling some of the tax to be invested to promote better waste management, is inadequately funded and the money is inappropriately focused. Following an examination of the projects and contributions made under the Scheme it is found that most of the contributions are not made towards projects which will fulfil the UK Government's perceived purposes. It is further submitted that there needs to be a more rational approach to waste management and legislation in Philadelphia forms a good case study of such an approach     

垃圾渗滤液电化学催化氧化法深度处理研究

研究利用电化学催化氧化法深度处理经生物处理后的垃圾渗滤液时，电压、氧化时间、氯离子浓度及温度对有机物降解的影响。试验结果表明：在电压3．5V，电流密度为7．0mA／cm^2．氧化时间2．5h．氯离子的浓度2000mg／L的条件下，垃圾渗滤液的CODCr由464．0mg／L降低到200．0mg／L，NH3^-N的去除率大于95％。     

有害废物安全填埋场衬里系统设计方案的研讨

本文通过沈阳有害废物安全填埋场双层衬里系统设计方案的分析论证，结合“八五”攻关课题内容提出研讨性意见，认为双层复合衫衬里系统不是必选的衬里构造．“八五”期间，应研制符合国情、技术上先进、经济上合理的安全填埋技术．     

吖啶橙非均相光敏氧化处理垃圾渗滤液的研究

用碳纤维负栽吖啶橙进行非均相处理垃圾渗滤液。结果发现，不但光敏氧化体系对废水COD去除率高，达到63．5％，而且吖啶橙光敏剂可以多次重复利用。当吖啶橙浓度为12mg／L时，获得了碳纤维吸附吖啶橙最佳量为1．5L／m^2：当光源采用200W白炽灯、光照距离约10cm时，获得了碳纤维处理垃圾渗滤液的最佳量5．6～7．5L／m^2，最佳面积负荷554．9gCOD／m^2。     

上海老港生活垃圾填埋场陈垃圾的基本特性研究

对上海老港生活垃圾填埋场6年填埋龄和10年填埋龄陈垃圾的基本特征进行了测试研究，这些特性包括粒径分布，臭味、微生物数量、含水率、总磷、总氮、饱和水力渗透系数等。研究结果：上海老港生活垃圾填埋场中6年以上填埋龄陈垃圾已可以开采用使用；对其多种用途的开发主要限于陈垃圾中粒径小于15mm的细料部分；此细料是极为优良的污染物生物处理基质。     

城市生活垃圾填理场及压缩站的环境影响探讨

简述了填埋法处理城市生活垃圾的全过程，分析这一过程中垃圾压缩站和垃圾填埋场的环境影响，并探讨了控制污染的对策措施。     

Sulfate reduction behavior in pressure-bearing leachate saturated zone

Attention should be paid to the sulfate reduction behavior in a pressure-bearing leachate saturated zone. In this study, within the relative pressure range of 0–0.6 MPa, the ambient temperature with the highest sulfate reduction rate of 50°C was selected to explore the difference in sulfate reduction behavior in a pressure-bearing leachate saturated zone. The results showed that the sulfate reduction rate might further increase with an increase in pressure; however, owing to the effect of pressure increase, the generated hydrogen sulfide (H₂S) could not be released on time, thereby decreasing its highest concentration by approximately 85%, and the duration extended to about two times that of the atmospheric pressure. Microbial community structure and functional gene abundance analyses showed that the community distribution of sulfate-reducing bacteria was significantly affected by pressure conditions, and there was a negative correlation between disulfide reductase B (dsrB) gene abundance and H₂S release rate. Other sulfate reduction processes that do not require disulfide reductase A (dsrA) and dsrB genes may be the key pathways affecting the sulfate reduction rate in the pressure-bearing leachate saturated zone. This study improves the understanding of sulfate reduction in landfills as well as provides a theoretical basis for the operation and management of landfills.     

Fenton法处理卫生填埋渗滤液——从模型放大到中试的问题初探

在中试厂中进行了Fenton法处理卫生填埋渗滤液的试验,以检验根据小试结果得出的统计模型。对三种不同渗滤液的试验发现,COD去除率与模型推出的几种最佳操作条件无关,三种渗滤液的COD去除率分别为35.0±2.2%、42.1±1.0%及50.6±5.6%。这表明不仅中试结果和模型预测(>80%)之间存在较大的差异,而且不同渗滤液的处理程度也存在一定的差异,其中一个原因是各种渗滤液的组分各有差异,因此不能用一种渗滤液的处理结果去预测其它渗滤液。而中试时较低的反应温度是造成试验结果和模型之间存在差异的另一个原因。