垃圾自动分类处理设备问世

都市垃圾自动分类全资源回收处理系统是2000年世界最新的环保专利技术,此系统发明者香港籍谢明明先生经过多年努力,在充分了解生活垃圾复杂性的基础上,摸索生活垃圾存在的规律,成功研制了此套系统,不但可将生活垃圾自动分类,还可将垃圾资源全部回收。本系统的优势是建造成本低、运行费用成本低,并可设置在城市周边或填埋场,而且不会形成二次污染,此系统发明将会是生活垃圾处理领域一次质的飞跃。设备投资比进口焚化炉低80％,日处理500吨设备约5000万人民币,包括焚烧设备、有机肥处理设备、污水处理设备。用地范围只占焚化炉的10％,不但延长填埋场的寿命,并可防止填埋场的污水浸透,污染地下水源。 (张强)     

生活垃圾填埋场再开采复用技术在我国的应用前景

目前,我国各地正在运行的生活垃圾填埋场多为20世纪70年代以后尤其是80年代中后期建造的,大部分填埋场已经达到或即将达到使用年限,填埋场的再建设再利用问题日益尖锐.随着我国城市化进程的加快,在我国建设生活垃圾填埋场将面临土地和资金两大突出问题,为解决这一困境,提出对已封场的填埋场进行再开采复用的技术出路,并从技术、经济及开挖后稳定化垃圾出路几个方面对其可行性进行了综合探讨,认为在我国土地短缺、资金不足、城市生活垃圾产量巨大且迅速增加的社会经济背景下,考虑对已封场城市垃圾填埋场进行再开采复用是一条较好的出路,是一条值得引起我国城市垃圾管理与处置界重视的技术对策.     

矿化垃圾治理技术的应用

以某非正规垃圾填埋场为例,对填埋年限15年以上的矿化垃圾进行治理,开展矿化垃圾筛分治理技术的应用,其成分腐殖质可与营养土混合用作绿化使用,其可燃物、金属等回收利用,剩余渣土运至卫生填埋场处置,实现垃圾的资源化处理,消除污染来源,释放填埋场地。     

德国生活垃圾填埋场开挖经验借鉴

通过描述德国对生活垃圾填埋场进行开挖的审批流程、工艺、开挖出来的垃圾组分、开挖后的环境影响及开挖费用,试图解析其对中国填埋场开挖的借鉴意义。     

利用生活垃圾填埋场上建设飞灰固化物填埋场适宜性探讨

针对利用原有生活垃圾填埋场改扩建飞灰固化物填埋场,从勘查设计和建设角度,通过与常规生活垃圾填埋的安全和环保各相关因素对比,分析扩建前后填埋场稳定性、防渗及导排系统等勘察设计要点,研讨扩建工程新老填埋堆体基础层、防渗及导排系统等安全环保关键技术及扩建的适宜性,为扩建的可行性研究提出较为系统的技术论证思路.     

矿化垃圾填埋场的综合治理

以矿化垃圾作为研究对象,对矿化垃圾填埋场进行综合治理,使填埋场垃圾得到资源化利用,将填埋场土地恢复使用,提升垃圾资源化利用后产生的经济效益。     

日本垃圾填埋场的全生命周期管理

从填埋方式、日常维护管理、封场管理、土地再利用等方面整理日本垃圾填埋场全生命周期的管理方式,梳理日本垃圾填埋场日常维护管理的各类监控指标,介绍填埋场的扩容技术、封场基准及土地的再利用方法,以期对我国垃圾填埋场的管理提供镜鉴.     

利用焚烧富余能力释放填埋库容的研究——以南方某市为例

对利用焚烧富余处理能力释放填埋场库容空间的问题进行讨论与研究,从富余焚烧处理能力、焚烧工艺适应性、填埋堆体开挖条件和填埋库容空间再利用等技术领域展开,认为利用焚烧富余处理能力释放填埋场库容空间在技术上可行。以南方某市为案例,根据生活垃圾量和焚烧处理能力相关数据进行测算,预测富余焚烧处理能力出现的时间和富余量,选择满足焚烧入炉要求的陈腐垃圾,开挖后不经筛分直接与原生活垃圾掺烧处理。     

垃圾填埋场矿化垃圾资源化利用研究现状及进展

垃圾填埋是我国处理垃圾的主要方式,但目前填埋场库存已经很难满足垃圾处理的需求,因此对矿化垃圾的开采和利用显得尤为重要。综述了矿化垃圾理化特性研究进展,讨论了矿化垃圾处理废水、矿化垃圾在土壤以及在其他方面的应用,为实现填埋场的可持续利用提供了参考。     

某生活垃圾卫生填埋场及周边地区臭气分析

重点以某垃圾填埋场恶臭污染检测结果为依据,通过120 h不间断检测,对垃圾填埋场所有恶臭气体源和其影响半径6 km范围内的所有周边区域进行采样检测,并对其检测结果进行比对分析,按照恶臭气体产生的时间规律、距离规律,分析在不同情况下恶臭气体对周边环境产生的影响,并总结恶臭气体产生源以及恶臭产生规律,为采取有效的除臭措施提供科学的依据。     

Rehabilitation of El Yahoudia dumping site, Tunisia

As in all developing countries, cities in Tunisia face serious problems of environmental pollution caused mainly by the inadequate and inefficient final disposal of their generated solid wastes. The Tunisian government launched a development program including the construction of landfills in the main cities and the closure of the contaminated sites issued from solid wastes landrising practice. The project of the Henchir El Yahoudia landfill restoration is the first experience in this programme. It has been suggested to convert the site to a green park and to implement an ornamental plant nursery. The whole surface of the landfill is approximately 100 ha from which 30 ha have been already transformed to an urban recreational area and the remaining 70 ha have to be characterized for the project extension. A field investigation by boring was conducted in order to define the geological and the hydrogeological conditions, the vertical and horizontal wastes layer extension, content and degree of decomposition and the composition and quantities of leachate and landfill gas. Representative samples of waste, soil, groundwater and leachate were collected for laboratory analyses. Several of these borings were converted to piezometers to define the flow regime in the site. The results showed that the biogas (CH4, H2S, and CO2), leachate and waste, distribution in the site is mainly affected by the temporal variation of the site operating method. The underlying fissured clay layer facilitated leachate infiltration into the groundwater where high BOD, COD and nitrogen concentrations were registered.     

Perpetual landfilling through aeration of the waste mass; lessons from test cells in Georgia (USA).

Municipal solid waste (MSW) landfills worldwide are experiencing the consequences of conventional landfilling techniques, whereby anaerobic conditions are created within the landfilled waste. Under anaerobic conditions within a landfill site slow stabilization of the waste mass occurs, producing methane, (an explosive 'green house' gas) and leachate (which can pollute groundwater) over long periods of time. As a potential solution, it was demonstrated that the aerobic degradation of MSW within a landfill can significantly increase the rate of waste decomposition and settlement, decrease the methane production and leachate leaving the system, and potentially increase the operational life of the site. Readily integrated into the existing landfill infrastructure, this approach can safely and cost-effectively convert a MSW landfill from anaerobic to aerobic degradation processes, thereby effectively composting much of the organic portions (one of the potentially polluting elements in a conventional landfill site) of the waste. This paper summarizes the successful results of two separate aerobic landfill projects located in Georgia (USA) and discusses the potential economic and environmental impacts to worldwide solid waste management practices.     

Graded landfill requirements in South Africa--the climatic water balance classification.

Landfilling in South Africa is controlled by a set of statutory Minimum Requirements, based on a landfill classification system. Landfills are classified according to the type of waste, the projected final size of the landfill and the climate. Climate is important as climatic conditions in South Africa vary from humid sub-tropical in the east, to semi-arid on the central plateau, to semi-desert in the west. Anti-pollution measures are closely related to climate and size, with the pollution potential of small, general (i.e. domestic) waste landfills in dry climates being regarded as negligible. At the other end of the scale, large landfills where hazardous wastes are disposed have a serious pollution potential and must be designed as containment systems. The paper describes the method currently in use for deciding on the climatic classification of a site, followed by the new method that will be adopted when the latest revision of the Minimum Requirements appears shortly.     

Hazardous chemical site remediation through capping: Problems with long-term protection

The capping of waste management units and contaminated soils is receiving increasing attention as a low-cost method for hazardous chemical site remediation. Capping is used to prevent further groundwater pollution by existing waste management units and contaminated soils through limiting the moisture that enters the wastes. In principle, for wastes located above the water table, the construction of an impermeable cap can prevent leaching of the wastes (leachate generation) and groundwater pollution. In practice, appropriately designed and constructed RCRA caps can provide for only short-term prevention of groundwater pollution. Alternative approaches are available for capping of wastes that can be effective in preventing moisture from entering the wastes and concomitant groundwater pollution. These approaches recognize the inability of the typical RCRA cap to keep wastes dry for as long as waste constituents will be a threat and, most importantly, provide the necessary funds to effectively address all plausible worst-case scenario failures that could occur at a capped waste management unit or contaminated soil area.     

Batch and column tests of metal mobilization in soil impacted by landfill leachate

The percolation of landfill leachate, even in the absence of a high concentration of specific pollutant, may induce a strong modification of soil chemical and physical characteristics, due to the alteration of the natural equilibrium between the aqueous phase and the soil matrix. As a result, a huge amount of cations can be solubilized, thus inducing groundwater pollution.In this work batch and column experiments of metal mobilization from a soil sampled down gradient of a municipal waste landfill in Northern Italy are presented. The experiments were initially performed in batch scale on soil slurries at different pH and Eh. Distilled water was used first and then a groundwater sampled down-gradient in the same site. Subsequently, to better simulate the aquifer conditions, 50 d column tests were performed on 15 kg of saturated soil. The concentrations of Fe, Mn, and Ni were evaluated when these selected environmental parameters were altered. Results indicated a greater release when acidic conditions were achieved, a positive effect in this case of the addition of an oxidant and a great Mn mobilization when negative redox potentials were established.     

Case study of landfill reclamation at a Florida landfill site

A landfill reclamation project was considered to recover landfill airspace and soil, reduce future groundwater impacts by removing the waste buried in the unlined area, and optimize airspace use at the site. A phased approach was utilized to evaluate the technical and economic feasibility of the reclamation project; based on the results of these evaluations, approximately 6.8 ha of the unlined cells were reclaimed. Approximately 371,000 in-place cubic meters of waste was mined from 6.8 ha in this project. Approximately 230,600 cubic meters of net airspace was recovered due to beneficial use of the recovered final cover soil and reclaimed soil as intermediate and daily cover soil, respectively, for the current landfill operations. This paper presents the researchers’ landfill reclamation project experience, including a summary of activities pertaining to reclamation operations, an estimation of reclamation rates achieved during the project, project costs and benefits, and estimated composition of the reclaimed materials.     

Transforming an open dump into a sanitary landfill: a development effort in waste management

Upgrading a crude dump site into a sanitary landfill is a very challenging task; Matuail landfill site in Dhaka posed just such a challenge. From the very beginning, the existing disposal site had been used for the crude dumping of solid wastes. All types of solid wastes were haphazardly disposed of all over the site. The existing drainage channels of the dumping ground were not operational due to blockage by indiscriminate waste dumping. A large amount of leachate oozing out from the waste mixed with storm water and made the site esthetically very displeasing and environmentally unsound. This adverse situation sometimes caused disruption of the waste vehicular movement. Step-by-step improvement measures have been taken in the open dump to make it controlled and sanitary by adopting simple and locally available materials, technical guidelines, and construction techniques.     

Site selection of a waste disposal facility in Kuwait,Arabian Gulf

The study is part of a programme on solid waste management in the Shuiba Industrial Area in Kuwait. Potential landfill sites were identified and evaluated in terms of environmental, technical and socio-economic factors. Exclusion/avoidance criteria were formulated and used for a preliminary screening, which resulted in two candidate sites. A set of site selection criteria was then compiled and used in a multidisciplinary study of the candidate sites that included field investigation, soil analysis, and an assessment of groundwater, ecology and socio-economic setting. A weighting/scaling scoring system was applied to the final evaluation of the results and the selection of the most suitable site. This work also presents recommendations on operations and management of the landfill to ensure maximum protection of the environment and public health.     

GIS-based approach for optimized siting of municipal solid waste landfill

The exponential rise in the urban population of the developing countries in the past few decades and the resulting accelerated urbanization phenomenon has brought to the fore the necessity to develop environmentally sustainable and efficient waste management systems. Sanitary landfill constitutes one of the primary methods of municipal solid waste disposal. Optimized siting decisions have gained considerable importance in order to ensure minimum damage to the various environmental sub-components as well as reduce the stigma associated with the residents living in its vicinity, thereby enhancing the overall sustainability associated with the life cycle of a landfill. This paper addresses the siting of a new landfill using a multi-criteria decision analysis (MCDA) and overlay analysis using a geographic information system (GIS). The proposed system can accommodate new information on the landfill site selection by updating its knowledge base. Several factors are considered in the siting process including geology, water supply resources, land use, sensitive sites, air quality and groundwater quality. Weightings were assigned to each criterion depending upon their relative importance and ratings in accordance with the relative magnitude of impact. The results from testing the system using different sites show the effectiveness of the system in the selection process.