Inter-Municipal Landfill Site Selection Using Analytic Network Process

Selecting the most suitable landfill site is important to prevent any negative ecological and socio-economic effects. Spatial analysis takes into consideration local environmental regulations and adopted acceptance criteria that are important considerations in site selection. This paper is a case study to determine the suitability of an inter-municipal solid waste landfill site for the city of Khomeynishahr and its six adjacent cities, with a total population of half a million people. A multi-criteria evaluation method emphasising geographical information systems (GIS) techniques was used to identify suitable landfill sites. A combination of Boolean logic, Fuzzy logic and Analytic Network Process (ANP) was used for prioritising the associated criteria and selecting a suitable landfill site. This method is capable of being applied to complex problems with uncertainty and non-hierarchical structure and allows for the consideration of interdependence relationships of decision criteria within and between levels. Taking advantage of the ANP method, the selected landfill site priorities can be identified by considering the variation and relative importance of decision criteria for each site, which cannot be considered in other decision-making methods, such as Analytic Hierarchy Process (AHP). The results showed the significant importance of residential area and water resources protection in landfill site selection. This study indicates that the integrated method can provide environmental decision makers and planners with a promising tool.     

南水北调工程北京市受水区非正规垃圾填埋场控高水位研究

近年来北京市平原区地下水污染范围已呈现从城区向郊区延伸、从浅层向深层扩散的趋势.地下水污染源调查评价研究表明,垃圾填埋堆放场是造成地下水污染的主要污染源之一.以北京市南水北调工程受水区内存在被浸泡可能的27个非正规垃圾填埋场为研究对象,在垃圾填埋场基本特征的基础上,对典型非正规垃圾填埋场进行水文地质勘察和水、土、垃圾样...     

城市生活垃圾卫生填埋场选址的水文地质条件约束

城市生活垃圾卫生填埋场的选址涉及多方面因素.本文充分论述了水文地质条件对填埋场选址的约束,以及如何对水文地质条件进行充分调查和勘查.优选出安全可靠的城市垃圾的地下填埋场.使城市的发展和环境保护的需求之间达到最优化的联合.重点分析了时地下填埋场选址的地质条件约束.包括含水层的特征、地下水特征、地质、岩性、地质构造等因素.最后说明了城市垃圾填埋场地质勘查的工作程序、步骤和方法.     

生活垃圾填埋场渗滤液处理规模的探讨

研究了生活垃圾填埋场渗滤液产生的不同途径,以垃圾填埋过程及场外影响因素为研究对象,以入渗系数法为基础,提出了逐年平均法预测渗滤液产生量的公式,以此确定填埋场渗滤液处理系统的设计规模。在此基础上,结合工程实例,验证了预测方法的可靠性。     

垃圾土边坡失稳离心模拟试验研究

垃圾围城现象在中国十分明显,其潜在的危害是在极端气候和环境条件下,由于强降雨和渗滤液回灌引起有效应力降低,从而导致填埋体发生滑坡,甚至演化为流滑现象。本文根据中国城市垃圾土的特点,配置了垃圾土试样并制作模型,采用大型土工离心机针对不同龄期的垃圾土边坡在多种工况组合条件下进行了模型试验。为了使模型边坡在高加速度场下达到破坏,开发了变角度模型箱。在离心机转动过程中,通过调整模型箱的角度来增加边坡的坡度,直至垃圾土边坡模型达到破坏。试验过程中同时监测模型变形,通过数据分析,发现了垃圾土边坡变形及失稳的一般性规律。本文同时给出一种离心模拟试验中模型边坡安全储备的估算方法。     

受扩建工程影响的老垃圾填埋场沉降分析

以苏州七子山垃圾填埋场扩建工程为例，利用数值模拟和分层总和沉降法分析老场垃圾堆体在新填埋堆体作用下的“二次沉降”规律。结合老场垃圾土的现场试验数据，利用有限差分软件FLAC3D对堆载过程中老场垃圾土的沉降进行了模拟。结果表明，在新场封场时，老场沉降呈“穹隆”状；最大沉降发生在中间部位，最大沉降量约为老场堆体厚度的20%左右。数值分析计算结果约为分层总和法计算结果的1.2倍。     

淮河流域信息化系统建设与管理

淮河流域已建成气象信息系统、水情信息采集和处理系统及防汛通信系统,在防汛工作中起到了重要作用,目前仍有水情、工情、灾情信息采集系统、防汛决策支持系统等信息化系统在规划建设过程中。在建设中应循序渐进,与管理体制改革,与应用需要相结合,才能更好地为流域防灾减灾提供决策支持。     

生活垃圾填埋场对地下水的污染研究

从分析河北省生活垃圾及其渗沥液化学成分入手,确定生活垃圾及其渗沥液的主要成分。通过实例,采用污染指数法,分析研究生活垃圾填埋场对地下水的污染情况,并总结河北省18个生活垃圾填埋场对地下水的污染规律。结果表明:生活垃圾填埋场总体上已对地下水造成了较严重污染,其污染程度因垃圾填埋场所处的地貌单元不同而有差别。     

非正规垃圾填埋场地下水污染控制技术比较

以我国北方某非正规垃圾填埋场为例,应用数值模拟方法,分别对不同的地下水污染控制技术效果进行了模拟预测。结果显示:针对研究区的水文地质结构特征及场区内垃圾特性,抽水为短期内最优控制技术;源项去除控制技术则为长期的最优选择;帷幕灌浆、河流防渗以及顶部覆盖不透水层的控制技术,只能阻滞场区内潜水中污染物向外迁移,无法阻止污染物对微承压水的入渗。     

The impact of contamination from a municipal solid waste landfill (zagreb,croatia) on underlying soil

The present study was conducted on the main landfill of the city of zagreb which contains about 5 million tons of waste disposed of directly onto highly permeable alluvial sediments. The investigations were aimed at assessing the impact of contamination from the landfill on underlying soil and comprised the determination of a broad spectrum of inorganic and organic constituents in the samples (size fractions <2 mm) of solid waste, soil and aquifer sediments. Both the total content of various contaminants as well as their part which is readily leachable with water were determined in the examined samples. Compound classes identified in the landfill can be classified into the two main categories: (I) markers of biological waste and of its microbial transformation (ammonia, dissolved organic carbon, short-chain aliphatic acids, phenols, derivatives of abietic acid) and (2) markers of anthropogenic waste (toxic metals, hydrocarbons, chlorinated hydrocarbons, surfactant-derived compounds, phthalates, pharmaceutical chemicals). The complex assemblages of contaminants were shown to change dramatically during the transport from the solid waste through unsaturated zone of the soil to aquifer sediments. It was shown that, in addition to the vertical infiltration of leachate from the solid waste, the hydrological regime of groundwater has also a strong impact on the contaminant distribution in soils below the landfill.     

填埋场渗滤液水位对填埋气收集的影响研究

为研究我国填埋场中气体运移规律建立了考虑我国城市固废组分特点的填埋场液-气运移耦合模型,应用此模型对西安江村沟填埋场现场抽气试验进行模拟分析。结果表明:抽气竖井影响半径随饱和度升高明显缩小;抽气竖井影响范围随堆体水位下降而显著提高,降低堆体水位可显著提高填埋气收集效率。根据分析结果建议对于典型高厨余固废含量填埋场,在设计抽气竖井间距时应考虑高厨余垃圾组分特点及降解规律,并且采取相应措施对填埋场中渗滤液水位进行控制,以提高填埋气收集效率。     

黄土丘陵区危险废物填埋场地下水环境影响评价

为系统识别危险废物填埋场项目建设可能对区域地下水环境造成的影响,结合黄土丘陵区特殊的水文地质条件特征,建立基于包气带污染物垂向迁移模拟的数值模型方法。从拟建危险废物填埋场工程布局及可能的污染风险识别出发,设置地下水环境影响评价要素及情景,开展地下水环境影响识别和预测分析。影响预测结果表明:在填埋区防渗层事故破损出现泄漏的情景下,随渗滤液进入土壤环境的铅、镍污染物穿透包气带需18～19 a,事故情景下污染物渗漏不会影响区域地下水环境。在按照相关技术规范要求对填埋场区采取有效防渗措施,并完善填埋场防渗系统的渗漏破损检测系统建设的前提下,该选址地下水环境保护目标可行。     

Contribution of Geographic Information Systems and location models to planning of wastewater systems.

This paper presents the contributions of Geographic Information Systems (GIS) and location models towards planning regional wastewater systems (sewers and wastewater treatment plants) serving small agglomerations, i.e. agglomerations with less than 2,000 inhabitants. The main goal was to develop a decision support tool for tracing and locating regional wastewater systems. The main results of the model are expressed in terms of number, capacity and location of Wastewater Treatment Plants (WWTP) and the length of main sewers. The decision process concerning the location and capacity of wastewater systems has a number of parameters that can be optimized. These parameters include the total sewer length and number, capacity and location of WWTP. The optimization of parameters should lead to the minimization of construction and operation costs of the integrated system. Location models have been considered as tools for decision support, mainly when a geo-referenced database can be used. In these cases, the GIS may represent an important role for the analysis of data and results especially in the preliminary stage of planning and design. After selecting the spatial location model and the heuristics, two greedy algorithms were implemented in Visual Basic for Applications on the ArcGIS software environment. To illustrate the application of these algorithms a case study was developed, in a rural area located in the central part of Portugal.     

垃圾土大尺寸平板载荷试验与变形特性

垃圾土的组成成分极其复杂,且具有较强的时空变异性.获得垃圾土准确的承载力与变形特性对后续的大面积填筑土方进行堆山造景及安全的正常运营具有十分重要的意义.然而,对其承载力与变形特性的准确确定十分困难,大尺寸平板载荷试验是较为可靠的方法.通过载荷板尺寸为4 m×4 m的大型平板载荷试验,对武汉市某垃圾场内垃圾土层的工程性能...     

An intelligent visualisation and decision support system for decentralised wastewater treatment plants.

Current sanitation concepts of decentralised wastewater treatment and reuse raise the issue of monitoring and maintenance of such systems. To guarantee high quality of the recycled water, systems with high requirements concerning process technology are essential. With increasing numbers of decentralised treatment systems spread over far distances it will become more and more impossible and uneconomic to have expert personnel on site. Therefore, new visualisation and intelligent information systems are necessary. The paper describes the structure and 3D-demonstrations as a base for information visualisation. Up-to-date visualisation techniques, facilitating the cognition of context-adapted information, make it possible to maximise the amount of information presented to the user without overwhelming her or him. Concerning diagnosis and decision support systems in the domain of wastewater treatment, several interesting approaches are presented, estimating their applicability for decentralised wastewater treatment systems. The intelligent decision support system presented here consists of a combined ontology- and case-based reasoning system in addition to a process monitoring system. It is responsible for plausibility checks, error diagnosis, solution proposals, and optimisation suggestions.     

Nitrogen removal during leachate treatment: comparison of simple and sophisticated systems.

Membrane bioreactors (MBR) have become common in treating municipal wastewaters. Applied to leachates treatment MBR were also successful with pilot scale experiments and full-scale facilities as well. We succeeded previously in designing an efficient nitrification-denitrification process with an ethylene glycol byproduct as carbon source for denitrification. Moreover, an unexpectedly high inert COD removal efficiency was also observed in the full-scale MBR facility thereby making it possible to increase the operating time of the final GAC (Granulated Activated Carbon) adsorber. Since MBR are very sophisticated systems. Simpler and "lower" cost systems can also be considered. For example it is possible to nitrify leachates from sanitary landfill using a simple infiltration-percolation technique with a low energy cost. To validate previously published laboratory experiments, a semi industrial-scale pilot installation was installed at the Montzen landfill site (Belgium). The process is based on infiltration-percolation through a granular bed. This well known process was modified to increase the load, notably by changing the support medium, adding an electric fan that is run intermittently and maintaining temperatures greater than 15 degrees C. The new material is a type of granular calcium carbonate with a large specific surface area. These technical improvements enabled the system to nitrify up to 0.4 kg NH4+-N/m3 of reactor bed per day at a hydraulic load of 0.35 m.d(-1), with an ammonia removal rate in the range of 80 to 95%. Despite the high ammonia nitrogen inlet concentrations, this system exhibits remarkable nitrification efficiency. Moreover, these performances are achieved in a batch mode system without recirculation or dilution processes. If complete nitrification is needed, it can be obtained in a second in series of bioreactors. The system can be classified as a low cost process. An international patent is pending. Possible performances of those systems were compared with the usual methods for leachates treatment.     

An integrated system for nonpoint source pollution modelling and management.

Modelling the impact of nonpoint source pollution (NSP) is a complex problem that has troubled water resource managers for many years when trying to set up proper management practices in catchment areas. In this paper, an integrated decision support system, NPSDSS (nonpoint source decision support system), was introduced to resolve this problem in a relatively easy way. The system was developed in a unique platform and integrated with the IMPULSE (integrated model of nonpoint source pollution processes) model, a stand alone geographic information system (GIS) toolbox, a well-structured database, a measure screening model, and an expert system, as well. The system has been applied in the Dianchi Lake catchment area and shown to give a good perspective on providing useful recommendations for appropriate NSP management.     

Enhancing waste decomposition and methane production in simulated landfill using combined anaerobic reactors.

The design of leachate recirculation to enhance municipal solid waste decomposition, methane production and microbial activities was taken into account in this study by using the combined anaerobic reactors of a simulated high organic content landfill reactor and a stabilized fixed film anaerobic reactor. The latter aimed to treat high strength leachate from the simulated landfill reactor before recirculation back to the former reactor. The results showed the possibility to apply this technique to high organic waste landfill where rapid and accumulative acids formed in the leachate were removed and treated by a fixed film anaerobic reactor. In addition, the treated leachate when circulated back to the simulated bioreactor landfill helps accelerate waste decomposition and methane production by providing buffer capacity as well as diluting organic content in the leachate to achieve the favourable conditions for acidogen and methanogen, respectively, to rapidly enter into the methanogenesis phase.     

Comparing Two Multi-Criteria Methods for Prioritizing Wetland Restoration and Creation Sites Based on Ecological,Biophysical and Socio-Economic Factors

Wetland restoration has been recognized as a useful tool for improving water quality. Many studies have focused on developing strategies and models to optimize wetland performance. However, some important wetland placement characteristics have not been taken into account. In this research and unlike other studies, we included the social aspect (availability of public lands) as a fundamental factor to locate wetlands. Thus, environmental, biophysical and socio-economic factors were integrated through the comparison of two multi-criteria methods (a suitability model and a greedy algorithm). With nitrate removal as the main goal, the suitability model was applied considering the “terrain slope”, “proximity to watercourses” and “soil permeability”. The greedy algorithm was executed based on the “availability of public lands” and the “wetland restoration project costs”. These factors were chosen based on the Eu Life-CREAMAgua Flumen River project, which was carried out previously in the study area. Both the suitability model and the greedy algorithm provided critical information for siting a wetland and demonstrated the effectiveness of both approaches. By means of this study, we present highly applicable results as they are based on a real project (Eu Life-CREAMAgua Flumen River project), besides proposing and using the social factor as an innovative approach for the wetlands siting. This research and its possible adaptations can be used by decision makers to improve water quality using social and economic criteria, resulting in the efficient implementation of ecological-restoration projects.     

Flood Vulnerability Analysis by Fuzzy Spatial Multi Criteria Decision Making

Prioritization the sub-basins available in a basin to flood vulnerability analysis can be discussed in the form of a spatial multi criteria decision making (SMCDM) problem. In this research a fuzzy planning support system based on the spatial analysis using tow multi criteria decision making methods, Analytic Hierarchy Process (AHP) and TOPSIS (Technique for order-preference by similarity to ideal solution) is used. AHP method is used to determine the structure of decision making process and to estimate criteria weights and TOPSIS model is used to rank the sub-basins of Tehran urban basin as a study area regarding the flood vulnerable areas. Also in order to perform spatial analysis for decision-making process, a developed toolbox is used within the Geographic Information System (GIS). In this research a model is presented in which some vague concepts such as weight of decision making criteria are expressed in the form of linguistic variables to be converted to triangular fuzzy numbers. Finally, the sensitivity of model was analyzed by changing the weights of decision making criteria and providing of ranking scenarios. The results show the optimum alternatives for mitigation flood vulnerability in the study area.