锦州市典型危险废物处置场地下水基础环境调查与评估

地下水是水资源的重要组成部分,水量稳定、水质好,是农业灌溉、工矿和城市的重要水源之一。地下水污染是由于人为因素造成地下水水质恶化的现象,人为因素是造成地下水污染的重要原因。减少污染源的数量、污染物的排放量和加强对地下水的保护是控制地下水污染的有效途径。按照国家环保部要求,通过污染源筛选以及对典型危险废物处置场周边地下水基础环境状况调查和监测,掌握了大量的第一手数据,掌握了背景、常规、特征污染因子污染状况及污染物分布时空规律,来判断周边地下水是否受到污染和影响,为制定相应配套的污染控制方案提供科学的依据。     

四川天府新区地下水污染源荷载评估

地下水污染源荷载评估是地下水污染防治中一项重要内容,能为地下水污染防治提供污染危害等级数据。以四川天府新区为例,在收集污染源统计资料并开展地下水污染源调查基础上,筛选单个污染源的污染物的毒性(T)、污染的可能性(L)、污染物从污染源可能释放到地下水体的量(Q)3个定量指标,利用评分指数法获得单个污染源荷载风险等级值。利用GIS软件插值法编制8种类型污染源荷载等级分区图,根据各类污染源权重指标分区计算,最终得到地下水污染源荷载评估综合分区图,并将天府新区地下水污染源荷载分为5级。研究表明集中式工业园区对污染源荷载等级的贡献最大,二者具有高度的耦合性。     

锦州市典型工业污染源地下水基础环境调查与评估

通过污染源筛选,采用对照区、污染区、清洁区优化的控制性布点与功能性布点方法,对典型工业污染源锦州石化分公司周边地下水基础环境状况进行调查和监测,掌握了背景、常规、特征污染因子污染状况及污染物分布时空规律,监测结果显示,除亚硝酸盐、阴离子洗涤剂等个别生活类污染因子和石油类超标外,其余监测因子均达标。石化行业特征因子石油类所有点位全部超标,说明锦州石化分公司已对周边地下水造成污染扩散影响。     

气田开发过程中地下水环境保护方案初探

区域地下水环境的保护是气田开发过程中环境保护工作的重点之一。通过现场调查和统计分析得知,外部污染源是影响当地地下水环境的主要因素,农田径流污染源是外部的主要污染源,以COD_Cr计其排放量分别约占外部污染源排放总量的67%,而钻井液漏失、天然气窜层、钻井废水排放等钻井作业是内部的主要污染源,其COD_Cr排放量约占内部污染源COD_Cr排放总量的62%,因而钻井作业的污染防治应是项目内部地下水污染防治工作的重点。根据地下水环境质量现状分析及变化趋势分析可知由于气田的开发建设,气田区地下水水质已受到一定程度的影响,特征污染物表现为COD_Cr、氨氮、氯化物、硝酸盐氮。为保护气田区地下水环境,分施工期和运营期两阶段设计了地下水环境保护方案,采取源头控制的清洁生产,至末端控制的污染治理并提出了突发污染事故应急预案,为气田的可持续开发提供指导。     

基于Visual Modflow的填埋场地下水污染迁移研究——以河北省保定市某飞灰填埋场为例

垃圾焚烧发电和稳定化飞灰填埋场模式的联合处置方式是目前处理城市生活垃圾的有效手段之一,但填埋场对地下水存在潜在的污染风险,因此研究填埋场污染物迁移规律对于填埋场建设和管理具有重要的意义。以河北省保定市某飞灰填埋场为例,采用Visual MODFLOW建立了地下水水流模型和溶质迁移模型,对河北省保定地区某填埋场典型污染物泄漏情景下的污染物迁移扩散情况进行预测,并对渗滤液调节池短时泄漏和库区底部连续泄漏两种非正常状态下污染物的迁移特征进行分析。研究结果表明：渗滤液调节池短时泄漏情景下,泄漏30d后采取应急措施切断污染源,形成的污染晕向地下水下游运移,污染扩散距离及范围不断变大,但污染晕最大浓度在迁移过程中随着地下水的稀释不断减小。模拟期间超标范围未超过厂区边界,在此情境下,只要在泄漏发生后及时采取应急措施切断污染源,可以确保将污染晕控制在一定范围内,避免对厂区周围地下水环境产生明显不利影响。库区底部连续泄漏情景下,污染扩散距离及范围不断变大,如不加控制,会影响下游敏感目标。因此,为避免污染泄漏对下游及敏感点地下水环境产生不利影响,必须在泄漏发现后及时采取抽提或渗透反应墙等有效措施阻断污染物...     

乌鲁木齐地区环境空气中TSP达标方案的探讨

TSP是乌鲁木齐市大气污染的首要污染物。根据TSP污染源调查和污染物源解析研究成果，对乌鲁木齐市TSP污染现状和污染物来源进行了分析，在对TSP污染进行科学预测的基础上，根据大气污染控制技术研究成果和污染治理经验。提出了TSP达标规划实施方案。     

扬州市区水环境质量现状及防治对策

通过对扬州市区境内河流和地下水的环境质量进行调查分析,结果表明:河流水质较好,城区污水都排入污水处理厂且处理厂正常运行,水质达标排放,主要的污染物是有机污染物;地下水达到水质标准,由于地质原因,主要污染指标为总硬度和总矿化度。但仍应加大污染防治力度,针对水环境现状和问题,采取有效措施,坚持深入开展环境宣传教育,依靠科技进步,科学防治环境污染,控制污染源,实行达标制度,提高人们自身环保意识,促进水资源的可持续利用。     

新疆铁路运输业污水治理对策研究

随着铁路运输生产的发展，水污染状况也将不断加剧。在治理水污染的过程中，应从系统的角度进行分析，选用技术上可行，经济上合理的对策方案，对改善环境发挥更大的作用。以乌局污染源调查和污染控制研究为例，讨论了主要污染物和主要污染源的确定及最佳治理对策，以求对铁路及其它行业污染治理提供帮助。     

十年来市桥水道水质变化及其工业与生活污染源数据定量分析

市桥水道受生活和工业污染源的共同污染,水质恶化,本文中对市桥水道水质进行了评价,得出水质变化趋势,对废水和污染物排放总量进行了定量分析,得出生活和工业污染源对市桥水道的污染贡献.     

浅谈地下水污染调查方法

地下水污染调查,是环境水文地质工作的一个中心内容。调查的主要目的是:以保护地下水供水水源为前提,查明地下水的污染状况,有害物质污染类别,污染过程和污染规律;确定地下水的污染源,判断地下水污染发展的趋势;为控制和消除污染,保护水源提出治理规划和防治措施;为完善水源地卫生防护带,为工业布局合理性提供依据,所以调查方法的科学性、综合性和逻辑性,是正确认识和查明地下水遭受各种因质污染的重要手段,是制定地下水水质改良方案,采取防御污染措施的先行步骤。鉴于地     

A procedure to design a Permeable Adsorptive Barrier (PAB) for contaminated groundwater remediation

A procedure to optimize the design of a Permeable Adsorptive Barrier (PAB) for the remediation of a contaminated aquifer is presented in this paper. A computer code, including different routines that describe the groundwater contaminant transport and the pollutant capture by adsorption in unsteady conditions over the barrier solid surface, has been developed. The complete characterization of the chemical–physical interactions between adsorbing solids and the contaminated water, required by the computer code, has been obtained by experimental measurements. A case study in which the procedure developed has been applied to a tetrachloroethylene (PCE)-contaminated aquifer near a solid waste landfill, in the district of Napoli (Italy), is also presented and the main dimensions of the barrier (length and width) have been evaluated. Model results show that PAB is effective for the remediation of a PCE-contaminated aquifer, since the concentration of PCE flowing out of the barrier is everywhere always lower than the concentration limit provided for in the Italian regulations on groundwater quality.     

Tool for assessment of process importance at the groundwater/surface water interface

The groundwater/surface water interface (GWSWI) represents an important transition zone between groundwater and surface water environments that potentially changes the nature and flux of contaminants exchanged between the two systems. Identifying dominant and rate-limiting contaminant transformation processes is critically important for estimating contaminant fluxes and compositional changes across the GWSWI. A new, user-friendly, spreadsheet- and Visual Basic-based analytical screening tool that assists in evaluating the dominance of controlling kinetic processes across the GWSWI is presented. Based on contaminant properties, first-order processes that may play a significant role in solute transport/transformation are evaluated in terms of a ratio of process importance (P_i) that relates the process rate to the rate of fluid transfer. Besides possessing several useful compilations of contaminant and process data, the screening tool also includes 1-D analytical models that assist users in evaluating contaminant transport across the GWSWI. The tool currently applies to 29 organics and 10 inorganics of interest within the context of the GWSWI. Application of the new screening tool is demonstrated through an evaluation of natural attenuation at a site with trichloroethylene and 1,1,2,2-tetrachloroethane contaminated groundwater discharging into wetlands.     

关于桂花村地下水污染事件的调查

采用红外光谱法、色谱－质谱联用技术和气相色谱法，对新都县某厂废水和桂花村地下水中有机污染物种类进行了定性、定量分析，找出了桂花村地下水中的有机污染物质，并界定了污染范围。     

Remediation of saturated soil contaminated with petroleum products using air sparging with thermal enhancement

Pollutants in the form of non-aqueous phase liquids (NAPLs), such as petroleum products, pose a serious threat to the soil and groundwater. A mathematical model was derived to study the unsteady pollutant concentrations through water saturated contaminated soil under air sparging conditions for different NAPLs and soil properties. The comparison between the numerical model results and the published experimental results showed acceptable agreement. Furthermore, an experimental study was conducted to remove NAPLs from the contaminated soil using the sparging air technique, considering the sparging air velocity, air temperature, soil grain size and different contaminant properties. This study showed that sparging air at ambient temperature through the contaminated soil can remove NAPLs, however, employing hot air sparging can provide higher contaminant removal efficiency, by about 9%. An empirical correlation for the volatilization mass transfer coefficient was developed from the experimental results. The dimensionless numbers used were Sherwood number (Sh), Peclet number (Pe), Schmidt number (Sc) and several physical-chemical properties of VOCs and porous media. Finally, the estimated volatilization mass transfer coefficient was used for calculation of the influence of heated sparging air on the spreading of the NAPL plume through the contaminated soil.     

APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS TO GROUNDWATER MONITORING NETWORK DESIGN1

ABSTRACT: Effective monitoring configurations for contaminant detection in groundwater can be designed by analyzing the spatial relationships between candidate sampling sites and aquifer zones susceptible to contamination. Examples of such zones are the domain underlying the contaminant source, zones of probable contaminant migration, and areas occupied by water supply wells. Geographic information systems (GIS) are well-suited to performing key groundwater monitoring network design tasks, such as calculating values for distance variables which quantify the proximity of candidate sites to zones of high pollution susceptibility, and utilizing these variables to quantify relative monitoring value throughout a model domain. Through a case study application, this paper outlines the utility of GIS for detection-based groundwater quality monitoring network design. The results suggest that GIS capabilities for analyzing spatially referenced data can enhance the field-applicability of established methodologies for groundwater monitoring network design.     

Integrated environmental monitoring and simulation system for use as a management decision support tool in urban areas

Leachates are generated as a result of water or other liquid passing through waste at a landfill site. These contaminated liquids originate from a number of sources, including the water produced during the decomposition of the waste as well as rain-fall which penetrates the waste and dissolves the material with which it comes into contact. The penetration of the rain-water depends on the nature of the landfill (e.g. surface characteristics, type and quantity of vegetation, gradient of layers, etc). The uncontrolled infiltration of leachate into the vadose (unsaturated) zone and finally into the saturated zone (groundwater) is considered to be the most serious environmental impact of a landfill. In the present paper the water flow and the pollutant transport characteristics of the Ano Liosia Landfill site in Athens (Greece) were simulated by creating a model of groundwater flows and contaminant transport. A methodology for the model is presented. The model was then integrated into the Ecosim system which is a prototype funded by the EU, (Directorate General XIII: Telematics and Environment). This is an integrated environmental monitoring and modeling system, which supports the management of environmental planning in urban areas.     

An integrated fuzzy-stochastic modeling approach for risk assessment of groundwater contamination

An integrated fuzzy-stochastic risk assessment (IFSRA) approach was developed in this study to systematically quantify both probabilistic and fuzzy uncertainties associated with site conditions, environmental guidelines, and health impact criteria. The contaminant concentrations in groundwater predicted from a numerical model were associated with probabilistic uncertainties due to the randomness in modeling input parameters, while the consequences of contaminant concentrations violating relevant environmental quality guidelines and health evaluation criteria were linked with fuzzy uncertainties. The contaminant of interest in this study was xylene. The environmental quality guideline was divided into three different strictness categories: "loose", "medium" and "strict". The environmental-guideline-based risk (ER) and health risk (HR) due to xylene ingestion were systematically examined to obtain the general risk levels through a fuzzy rule base. The ER and HR risk levels were divided into five categories of "low", "low-to-medium", "medium", "medium-to-high" and "high", respectively. The general risk levels included six categories ranging from "low" to "very high". The fuzzy membership functions of the related fuzzy events and the fuzzy rule base were established based on a questionnaire survey. Thus the IFSRA integrated fuzzy logic, expert involvement, and stochastic simulation within a general framework. The robustness of the modeling processes was enhanced through the effective reflection of the two types of uncertainties as compared with the conventional risk assessment approaches. The developed IFSRA was applied to a petroleum-contaminated groundwater system in western Canada. Three scenarios with different environmental quality guidelines were analyzed, and reasonable results were obtained. The risk assessment approach developed in this study offers a unique tool for systematically quantifying various uncertainties in contaminated site management, and it also provides more realistic support for remediation-related decisions.     

Groundwater Vulnerability Assessment for Organic Compounds: Fuzzy Multicriteria Approach for Mexico City

This study was based on a groundwater vulnerability assessment approach implemented for the Mexico City Metropolitan Area (MCMA). The approach is based on a fuzzy multicriteria procedure integrated in a geographic information system. The approach combined the potential contaminant sources with the permeability of geological materials. Initially, contaminant sources were ranked by experts through the Analytic Hierarchy Process. An aggregated contaminant sources map layer was obtained through the simple additive weighting method, using a scalar multiplication of criteria weights and binary maps showing the location of each source. A permeability map layer was obtained through the reclassification of a geology map using the respective hydraulic conductivity values, followed by a linear normalization of these values against a compatible scale. A fuzzy logic procedure was then applied to transform and combine the two map layers, resulting in a groundwater vulnerability map layer of five classes: very low, low, moderate, high, and very high. Results provided a more coherent assessment of the policy-making priorities considered when discussing the vulnerability of groundwater to organic compounds. The very high and high vulnerability areas covered a relatively small area (71 km² or 1.5% of the total study area), allowing the identification of the more critical locations. The advantage of a fuzzy logic procedure is that it enables the best possible use to be made of the information available regarding groundwater vulnerability in the MCMA.     

Conceptual Design of a System for Selecting Appropriate Groundwater Models in Groundwater Protection Programs

/ An effective groundwater protection program requires understanding of water flow and contaminant transport processes in the subsurface. Although many mathematical models have been developed to simulate the processes, few actually are used in groundwater protection programs due to the difficulties in data collection, model selection, and model implementation. This study presents a conceptual design of a GIS-supported model selection system that evaluates available data and mathematical models to facilitate groundwater protection programs. Steady-state groundwater and contaminant transport models applied in isotropic aquifers are placed into four classes to simulate conservative or nonconservative contaminant transports in simple or complex geohydrological conditions. After analyzing specific study objectives, available data, and model requirements, the proposed system selects a class of models that can be used in simulation and recommends any need for additional data collection. This study initiates an effort to integrate GIS, mathematical models, and expert knowledge in one system to promote the application of appropriate groundwater models. The new technology of GIS and digital data-base management makes it possible to develop such a system in practice.KEY WORDS: Groundwater models; Geographic information systems     

Optimal Environmental Management Strategy and Implementation for Groundwater Contamination Prevention and Restoration

An innovative management strategy is proposed for optimized and integrated environmental management for regional or national groundwater contamination prevention and restoration allied with consideration of sustainable development. This management strategy accounts for availability of limited resources, human health and ecological risks from groundwater contamination, costs for groundwater protection measures, beneficial uses and values from groundwater protection, and sustainable development. Six different categories of costs are identified with regard to groundwater prevention and restoration. In addition, different environmental impacts from groundwater contamination including human health and ecological risks are individually taken into account. System optimization principles are implemented to accomplish decision-makings on the optimal resources allocations of the available resources or budgets to different existing contaminated sites and projected contamination sites for a maximal risk reduction. Established management constraints such as budget limitations under different categories of costs are satisfied at the optimal solution. A stepwise optimization process is proposed in which the first step is to select optimally a limited number of sites where remediation or prevention measures will be taken, from all the existing contaminated and projected contamination sites, based on a total regionally or nationally available budget in a certain time frame such as 10 years. Then, several optimization steps determined year-by-year optimal distributions of the available yearly budgets for those selected sites. A hypothetical case study is presented to demonstrate a practical implementation of the management strategy. Several issues pertaining to groundwater contamination exposure and risk assessments and remediation cost evaluations are briefly discussed for adequately understanding implementations of the management strategy.