论龙岩市生活垃圾焚烧厂配套填埋场防渗工程施工管理

龙岩市生活垃圾焚烧厂为有效处理垃圾焚烧所产生的炉渣,以及经固化、稳定化处理后的飞灰,建设了配套填埋场。为杜绝填埋场渗沥液的外渗,同时防止地下水向填埋库区的渗入,并确保填埋场安全可靠的运行,减少渗沥液产生量,避免造成二次污染等问题,建设科学安全有效的防渗系统工程对于填埋场工程来说至关重要。通过对填埋场内部防渗系统的简要介绍及阐述,对适合此配套填埋场的防渗材料、衬层系统和衬层结构以及防渗材料铺设等问题进行了深刻的分析。     

某高龄期大型垃圾填埋场环境调查浅析

对某20世纪80年代末垃圾填埋场的外围环境和垃圾堆体进行了调查分析,调查对象包括堆体沉降和水位、陈腐垃圾、渗沥液、土壤等。通过定量分析可知,填埋堆体沉降量满足场地高度利用要求,有机质满足场地低度利用要求,周边环境中土壤样品达标;堆体渗沥液和场底土壤样品所检测指标存在未达标,发现填埋场底部存在渗漏现象;说明该垃圾堆体尚未稳定,建议进行水文调查和加强堆体的渗沥液导排与水位监测。     

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.     

生活垃圾填埋场陈垃圾基本特性及再利用

填埋场已填埋陈垃圾具有丰富的资源,我国填埋量已达几千万吨.通过对上海老港生活垃圾填埋场6年填埋龄和10年填埋龄陈垃圾基本特性的测试研究,揭示出填埋6年以上的陈垃圾已具有相当稳定的性状,原始垃圾特征已完全消失,开挖后没有异味,在组成上除部分大颗粒无机物和大块难降解有机物外,其余部分已腐化为类土壤物质,可以开采再利用.陈垃圾中类土壤部分在物理化学性质、水力学和微生物学性质上均表现出在自然条件下难以形成的、极为优良的基质特征,可用作污染物生物处理基质或作物培育基质.     

西安市某大型废弃物综合处置场设计及建设案例分析

介绍了西安市固体废弃物综合处置场项目的设计、建设和运营过程。首先,概括介绍了该项目的背景概况、目标规划和处理规模等情况。其次,详细论述了项目设计的基本情况,例如填埋场各功能区总图布置的确定、坝体的设计、防渗系统结构的选用以及地下水及渗沥液导排、渗沥液收集等系统设计问题。最后,分析了建设过程中可能遇到的各种风险问题并提出了规避风险的思路方法,以及该项目部分飞灰填埋库区的试运营情况,对飞灰填埋作业进行了详细细致的要求,以期为后续正式投运积累了实操运行及管理经验。     

丹阳北庄生活垃圾填埋场地下水污染分析

建立了针对生活垃圾填埋场地下水污染问题的数学预测模型,以丹阳北庄生活垃圾填埋场工程为例,预测和分析了北庄生活垃圾填埋场渗滤液对地下水的污染。     

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。     

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。     

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。     

Occurrence of phenols in leachates from municipal solid waste landfill sites in Japan

The concentrations of 41 phenols in leachates from 38 municipal solid waste (MSW) landfill sites in Japan were measured. The main phenols detected in leachates were phenol, three cresols, 4-tert-butylphenol, 4-tertoctylphenol, 4-nonylphenol, bisphenol A, and some chlorophenols. The concentration levels of phenols were affected by the pH values of the leachates and the different types of landfill waste. The origins of phenol and p-cresol were considered to be incineration residues, and the major origin of 4-tert-butylphenol, bisphenol A, and 2,4,6-trichlorophenol was considered to be solidified fly ash. In contrast, the major origins of 4-tert-octylphenol and 4-nonylphenol were considered to be incombustibles. The discharge of leachates to the environment around MSW landfill sites without water treatment facilities can cause environmental pollution by phenols. In particular, the disposal of incineration residues including solidified fly ash and the codisposal of solidified fly ash and incombustibles might raise the possibility of environmental pollution. Moreover, the discharge of leachates at pH values of 9.8 or more could pollute the water environment with phenol. However, phenol, 4-nonylphenol, and bisphenol A can be removed to below the con centration levels that impact the environment around landfill sites by a series of conventional water treatment processes.     

Strength, leachability and microstructure characterisation of Na2SiO3-activated ground granulated blast-furnace slag solidified MSWI fly ash.

The chemical composition and the leachability of heavy metals in municipal solid waste incinerator (MSWI) fly ash were measured and analysed. For the leachability of unstabilized MSWI fly ash it was found that the concentrations of Pb and Cr exceeded the leaching toxicity standard. Cementitious solidification of the MSWI fly ash by Na2SiO3-activated ground granulated blast-furnace slag (NS) was investigated. Results show that all solidified MSWI fly ash can meet the landfill standards after 28 days of curing. The heavy metals were immobilized within the hydration products such as C-S-H gel and ettringite through physical encapsulation, substitution, precipitation or adsorption mechanisms.     

Co-gasification of municipal solid waste and material recovery in a large-scale gasification and melting system

This study evaluates the effects of co-gasification of municipal solid waste with and without the municipal solid waste bottom ash using two large-scale commercial operation plants. From the viewpoint of operation data, there is no significant difference between municipal solid waste treatment with and without the bottom ash. The carbon conversion ratios are as high as 91.7% and 95.3%, respectively and this leads to significantly low PCDD/DFs yields via complete syngas combustion. The gross power generation efficiencies are 18.9% with the bottom ash and 23.0% without municipal solid waste bottom ash, respectively. The effects of the equivalence ratio are also evaluated. With the equivalence ratio increasing, carbon monoxide concentration is decreased, and carbon dioxide and the syngas temperature (top gas temperature) are increased. The carbon conversion ratio is also increased. These tendencies are seen in both modes.Co-gasification using the gasification and melting system (Direct Melting System) has a possibility to recover materials effectively. More than 90% of chlorine is distributed in fly ash. Low-boiling-point heavy metals, such as lead and zinc, are distributed in fly ash at rates of 95.2% and 92.0%, respectively. Most of high-boiling-point heavy metals, such as iron and copper, are distributed in metal. It is also clarified that slag is stable and contains few harmful heavy metals such as lead. Compared with the conventional waste management framework, 85% of the final landfill amount reduction is achieved by co-gasification of municipal solid waste with bottom ash and incombustible residues. These results indicate that the combined production of slag with co-gasification of municipal solid waste with the bottom ash constitutes an ideal approach to environmental conservation and resource recycling.     

Assessing the environmental impact of ashes used in a landfill cover construction

Large amounts of construction materials will be needed in Europe in anticipation for capping landfills that will be closed due to the tightening up of landfill legislation. This study was conducted to assess the potential environmental impacts of using refuse derived fuel (RDF) and municipal solid waste incineration (MSWI) ashes as substitutes for natural materials in landfill cover designs. The leaching of substances from a full-scale landfill cover test area built with different fly and bottom ashes was evaluated based on laboratory tests and field monitoring. The water that drained off above the liner (drainage) and the water that percolated through the liner into the landfill (leachate) were contaminated with Cl^?, nitrogen and several trace elements (e.g., As, Cu, Mo, Ni and Se). The drainage from layers containing ash will probably require pre-treatment before discharge. The leachate quality from the ash cover is expected to have a minor influence on overall landfill leachate quality because the amounts generated from the ash covers were low, <3–30 l (m² yr)^?1. Geochemical modelling indicated that precipitation of clay minerals and other secondary compounds in the ash liner was possible within 3 years after construction, which could contribute to the retention of trace elements in the liner in the long term. Hence, from an environmental view point, the placement of ashes in layers above the liner is more critical than within the liner.     

Influence of tropical seasonal variations on landfill leachate characteristics--results from lysimeter studies

Considering the quality of design and construction of landfills in developing countries, little information can be derived from randomly taken leachate samples. Leachate generation and composition under monsoon conditions have been studied using lysimeters to simulate sanitary landfills and open cell settings. In this study, lysimeters were filled with domestic waste, highly organic market waste and pre-treated waste. Results over two subsequent dry and rainy seasons indicate that the open cell lysimeter simulation showed the highest leachate generation throughout the rainy season, with leachate flow in all lysimeters coming to a halt during the dry periods. More than 60% of the precipitation was found in the form of leachate. The specific COD and TKN load discharged from the open cell was 20% and 180% more than that of the sanitary landfill lysimeters. Types of waste material and kind of pre-treatment prior to landfilling strongly influenced the pollutant load. Compared to the sanitary landfill lysimeter filled with domestic waste, the specific COD and TKN load discharged from the pre-treated waste lysimeter accounted for only 4% and 16%, respectively. Considering the local settings of tropical landfills, these results suggest that landfill design and operation has to be adjusted. Leachate can be collected and stored during the rainy season, and recirculation of leachate is recommended to maintain a steady and even accelerated degradation during the prolonged dry season. The open cell approach in combination with leachate recirculation is suggested as an option for interim landfill operations.     

A hybrid method for quasi-three-dimensional slope stability analysis in a municipal solid waste landfill

Limited space for accommodating the ever increasing mounds of municipal solid waste (MSW) demands the capacity of MSW landfill be maximized by building landfills to greater heights with steeper slopes. This situation has raised concerns regarding the stability of high MSW landfills. A hybrid method for quasi-three-dimensional slope stability analysis based on the finite element stress analysis was applied in a case study at a MSW landfill in north-east Spain. Potential slides can be assumed to be located within the waste mass due to the lack of weak foundation soils and geosynthetic membranes at the landfill base. The only triggering factor of deep-seated slope failure is the higher leachate level and the relatively high and steep slope in the front. The valley-shaped geometry and layered construction procedure at the site make three-dimensional slope stability analyses necessary for this landfill. In the finite element stress analysis, variations of leachate level during construction and continuous settlement of the landfill were taken into account. The "equivalent" three-dimensional factor of safety (FoS) was computed from the individual result of the two-dimensional analysis for a series of evenly spaced cross sections within the potential sliding body. Results indicate that the hybrid method for quasi-three-dimensional slope stability analysis adopted in this paper is capable of locating roughly the spatial position of the potential sliding mass. This easy to manipulate method can serve as an engineering tool in the preliminary estimate of the FoS as well as the approximate position and extent of the potential sliding mass. The result that FoS obtained from three-dimensional analysis increases as much as 50% compared to that from two-dimensional analysis implies the significance of the three-dimensional effect for this study-case. Influences of shear parameters, time elapse after landfill closure, leachate level as well as unit weight of waste on FoS were also investigated in this paper. These sensitivity analyses serve as the guidelines of construction practices and operating procedures for the MSW landfill under study.     

Environmental assessment of incinerator residue utilisation

Incineration ashes may be treated either as a waste to be dumped in landfill, or as a resource that is suitable for re-use. In order to choose the best management scenario, knowledge is needed on the potential environmental impact that may be expected, including not only local, but also regional and global impact. In this study, A life cycle assessment (LCA) based approach was outlined for environmental assessment of incinerator residue utilisation, in which leaching of trace elements as well as other emissions to air and water and the use of resources were regarded as constituting the potential environmental impact from the system studied. Case studies were performed for two selected ash types, bottom ash from municipal solid waste incineration (MSWI) and wood fly ash. The MSWI bottom ash was assumed to be suitable for road construction or as drainage material in landfill, whereas the wood fly ash was assumed to be suitable for road construction or as a nutrient resource to be recycled on forest land after biofuel harvesting. Different types of potential environmental impact predominated in the activities of the system and the use of natural resources and the trace element leaching were identified as being relatively important for the scenarios compared. The scenarios differed in use of resources and energy, whereas there is a potential for trace element leaching regardless of how the material is managed. Utilising MSWI bottom ash in road construction and recycling of wood ash on forest land saved more natural resources and energy than when these materials were managed according to the other scenarios investigated, including dumping in landfill.     

An attempt to perform water balance in a Brazilian municipal solid waste landfill

This paper presents an attempt to model the water balance in the metropolitan center landfill (MCL) in Salvador, Brazil. Aspects such as the municipal solid waste (MSW) initial water content, mass loss due to decomposition, MSW liquid expelling due to compression and those related to weather conditions, such as the amount of rainfall and evaporation are considered. Superficial flow and infiltration were modeled considering the waste and the hydraulic characteristics (permeability and soil-water retention curves) of the cover layer and simplified uni-dimensional empirical models. In order to validate the modeling procedure, data from one cell at the landfill were used. Monthly waste entry, volume of collected leachate and leachate level inside the cell were monitored. Water balance equations and the compressibility of the MSW were used to calculate the amount of leachate stored in the cell and the corresponding leachate level. Measured and calculated values of the leachate level inside the cell were similar and the model was able to capture the main trends of the water balance behavior during the cell operational period.     

论城市生活垃圾填埋处置及资源化利用的循环经济产业模式

提出了城市生活垃圾填埋处置及资源化利用的循环经济产业模式,分析论述了该模式实施的关键点及其资源化优势,并通过案例估算突出其投资优势,最后提出了该模式产业化应用的发展建议.