北京市地下水污染源荷载影响评价

在阐述地下水污染源荷载影响基本概念的基础上,介绍了污染源荷载影响评价的3大要素:污染荷载等级、含水层敏感性及地下水价值,说明了评价体系、指标和方法及过程。根据主要污染源荷载分析,结合地下水环境现状,对北京市进行了分区,提出污染源管理措施。     

拉林河流域地下水污染特征分析

应用自主研发的傍河取水水质监测与污染预警管理系统对拉林河流域地下水进行污染评价和污染成因分析。通过对样品的采集和分析,说明拉林河流域地下水铁、锰、氨氮和硝酸盐劣于国家地下水环境3级标准,且空间分布具有较强的异质性,可能具有一定的环境生态风险。通过改进的模糊数学法评价拉林河流域地下水污染,提出针对傍河取水工程的地下水保护方案。     

某废弃农药生产场地地下水挥发性有机物污染健康风险评价

对常州某废弃农药生产场地地下水中挥发性有机物污染状况和健康风险进行了调查评价。结果表明，该场地地下水中挥发性有机物污染以苯系物、氯代苯类和氯代烃类为主；部分点位地下水健康风险评价结果超出可接受范围，可能危害人体。     

珠海金鼎工业园地下水水质演变及其对水污染防控的提示

以珠海金鼎工业园这一典型的滨海工业园为研究对象,对比分析了工业园建成后不同时期(2005—2007与2015—2022)园区地下水环境监测数据与稳定氢、氧、氮等多种环境同位素数据,探讨了该园区浅层地下水水质时空演变特征,分析了园区地下水水质的超标问题与诱因,并识别了园区地下水、主要离子与无机氮等成分的来源,明确了该浅层含水层特征指标对海水入侵的指示,为滨海工业园区地下水污染的管控提供了科学依据。     

广州市建设用地土壤污染风险管控和修复现状、问题与对策

通过调研广州市已经开展风险管控和修复的污染地块,分析其基本特征、调查评估和治理修复等情况,总结出该市建设用地土壤污染风险管控和修复工作中存在的土壤环境背景值研究缺乏、重金属污染地块修复面临困难、地下水风险管控起步晚、修复过程技术标准缺失等问题,并有针对性地提出开展土壤环境背景值研究、探索重金属污染地块适用修复模式、重视地下水风险管控、完善技术标准支撑体系等对策建议。     

北京城市副中心海绵城市建设对地下水环境影响评价

以城市副中心北运河西岸湿地（甘棠大桥段）作为典型面状海绵体,利用2018年5月—9月采集的300组地表水和地下水监测数据,分析典型海绵体地下水水化学特征及形成机制,探讨不同含水层之间水力联系,并以Cl-为指示因子,结合其他水化学指标研究分析典型面状海绵体建设背景下地下水与地表水之间的交互作用及影响程度。结果显示,在垂向上,10 m、20 m含水层地下水之间联系密切,且受大气降水影响明显;在平面上,地表水对10 m、20 m含水层组地下水的影响距离为90 m～120 m,地表水对30 m含水层组地下水的影响距离为80 m～90 m。     

我国污染场地含水层监测现状与技术研发趋势

通过分析我国污染场地含水层监测现状和污染场地环境管理需求,指出我国污染场地含水层监测的不足之处并探讨了我国污染场地含水层监测技术研发趋势.当前,我国污染场地含水层监测主要以地下水监测为主,且监测仪器设备简陋陈旧、技术手段落后,不能满足数量日益增长的污染场地环境管理需求,急需发展一批新型、高效、经济、实用的监测技术和监测...     

杭州市主城区浅层地下水水质现状

调查了杭州市主城区浅层地下水水质现状。结果表明,杭州市主城区浅层地下水污染较重,"三氮"超标现象普遍,而主要污染项目为NH3-N、NO2--N、IMn和总大肠菌群及细菌总数。指出,农业面源污染和生活污水,是造成杭州市主城区浅层地下水氮污染的主要原因。提出分析了地下水水质污染的成因。指出应加强地下水保护以及地下水资源的质量管理。进行科学、合理地开发利用,实现地下水水资源的可持续利用,支持杭州市国民经济的可持续发展。     

江苏某县地下水邻苯二甲酸酯类的检测与风险评价

在江苏某癌症高发区对地下水进行布点,采用固相萃取与气相色谱-质谱联用方法测定深层地下水和浅层地下水中邻苯二甲酸酯类(PAEs)的浓度。检测结果表明,地下水中PAEs污染程度较严重,邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二(2-乙基己基)酯(DEHP)均有超标现象,其中,丰水期深层地下水和枯水期浅层地下水中DBP超标率达到100%,最大超标10.7倍。PAEs总质量浓度均值为10 034.56~14 872.91 ng/L,丰水期总浓度均值大于枯水期,浅层地下水的总浓度均值大于深层地下水。采用优化的USEPA风险评价模型,对PAEs进行人体健康风险评价,评价结果表明,该地区52.5% 地下水的PAEs总致癌风险超过10^-6的水质监控值,总非致癌风险在可接受范围内。     

美国Surfer 8.0软件在地下水环境质量评价中的应用

通过Surfer 8.0软件在某地地下水环境评价中的应用实例,重点阐述了其在浅层地下水污染物浓度空间分布图绘制、地下水质量分区图绘制、地下水污染分区图绘制、区域地下水污染趋势分析、地下水污染原因分析等方面的应用。     

Assessment of groundwater vulnerability in the Yinchuan Plain,Northwest China using OREADIC

Groundwater vulnerability assessments provide a measure of the sensitivity of groundwater quality to an imposed contaminant load and are globally recognized as an essential element of all aquifer management and protection plans. In this paper, the vulnerability of groundwaters underlying the Yinchuan Plain of Northwest China is determined using OREADIC, a GIS-based assessment tool that incorporates the key characteristics of the universally popular DRASTIC approach to vulnerability assessment but has been modified to consider important additional hydrogeological factors that are specific to the region. The results show that areas of high vulnerability are distributed mainly around Qingtongxia City, Wuzhong City, Lingwu City, and Yongning County and are associated with high rates of aquifer recharge, shallow depths to the water table, and highly permeable aquifer materials. The presence of elevated NO₃⁻ in the high vulnerability areas endorses the OREADIC approach. The vulnerability maps developed in this study have become valuable tools for environmental planning in the region and will be used for predictive management of the groundwater resource.     

Assessment of Ground Water Vulnerability and its Application to the Development of Protection Strategy for the Water Supply Aquifer in Owerri, Southeastern Nigeria

Pollution vulnerability of theOwerri regional water supply aquifer wasevaluated as a basis for developing appropriateprotection strategy for the groundwaterresource. The assessment was accomplished usingLegrand, GOD, Siga and DRASTIC models.Techniques of the models generally involvedparameters rating and point count systems, whichare based on the evaluation of various parameterin relation to their capacity for enhancing orattenuating contaminants in the groundwatersystem. Field and laboratory evaluations of theparameters indicate that the Owerri areagenerally occupies a nearly, flat topographywith a relatively high groundwater recharge. Thearea is underlain by predominantly sandyfacies in the Northern area which grades intogravelly sequences towards the southwest. TheSoutheastern area is distinguished by thickclayey facies that thin westwards towards theOwerri metropolis. Effective hydraulicconductivity (Kz) in the downward directionranges from 1.44 × 10^-3 to 5.6 × 10^-9 m s^-1; with the upper limits reflecting coarsesands and gravelly units. The amount of clay andclay-size particles in the sandy and gravellyunits is negligible, suggesting that thesorptive capacity of the units is low. Depth towater table decreases southwards while hydraulichead gradients vary between 0.09 and 0.22.Groundwater occurs in unconfined conditions inmost places except in the southeastern zonewhere it is semi-confined due to the presence ofa clayey unit. The groundwater vulnerabilitymap developed on the basis of the models andseveral other thematic maps shows that theOwerri metropolis and the southwest area ofOwerri have high vulnerability, indicatinggroundwater pollution. The existing wastedisposal sites in these sub-areas should beabandoned and rehabilitated to forstall furtherpollution of the groundwater system. Areas tothe North and Southeast of Owerri have moderateand low vulnerabilities, respectively,indicating the relatively lower sensitivity ofthe groundwater system in the sub-areas tocontamination. The lower sensitivity couldfurther be matched with properly engineeredsanitary landfills in the event of choice ofsites, as an additional protective strategy forthe groundwater system.     

MONITORING OF SPATIAL AND TEMPORAL HYDROCHEMICAL CHANGES IN GROUNDWATER UNDER THE CONTAMINATING EFFECTS OF ANTHROPOGENIC ACTIVITIES IN MERSIN REGION, TURKEY

The development of groundwater resources for water supply is a favored way in Turkey. The Berdan alluvial aquifer in Mersin is particularly productive, but little is known about the natural phenomena that govern the groundwater quality and the contamination sources in this region. During 2001 and 2002, water samples for chemical analysis were obtained from 27 wells and from two points of Berdan River and analyzed by ICP. Main chemical characteristics of sampled groundwater define two aquifers, which were also determined by hydrogeological investigations. The groundwater produced from some of the wells was affected by anthropogenic activities temporally and spatially by seawater intrusion. Berdan River is polluted with the wastewater discharges and river water also influences the groundwater quality.     

Tailoring groundwater quality monitoring to vulnerability: a GIS procedure for network design

Monitoring networks aiming to assess the state of groundwater quality and detect or predict changes could increase in efficiency when fitted to vulnerability and pollution risk assessment. The main purpose of this paper is to describe a methodology aiming at integrating aquifers vulnerability and actual levels of groundwater pollution in the monitoring network design. In this study carried out in a pilot area in central Italy, several factors such as hydrogeological setting, groundwater vulnerability, and natural and anthropogenic contamination levels were analyzed and used in designing a network tailored to the monitoring objectives, namely, surveying the evolution of groundwater quality relating to natural conditions as well as to polluting processes active in the area. Due to the absence of an aquifer vulnerability map for the whole area, a proxi evaluation of it was performed through a geographic information system (GIS) methodology, leading to the so called “susceptibility to groundwater quality degradation”. The latter was used as a basis for the network density assessment, while water points were ranked by several factors including discharge, actual contamination levels, maintenance conditions, and accessibility for periodical sampling in order to select the most appropriate to the network. Two different GIS procedures were implemented which combine vulnerability conditions and water points suitability, producing two slightly different networks of 50 monitoring points selected out of the 121 candidate wells and springs. The results are compared with a “manual” selection of the points. The applied GIS procedures resulted capable to select the requested number of water points from the initial set, evaluating the most confident ones and an appropriate density. Moreover, it is worth underlining that the second procedure (point distance analysis [PDA]) is technically faster and simpler to be performed than the first one (GRID?+?PDA).     

A Methodology for Space-Time Classification of Groundwater Quality

Safeguarding groundwater from civil, agricultural and industrial contamination is matter of great interest in water resource management. During recent years, much legislation has been produced stating the importance of groundwater as a source for drinking water supplies, underlining its vulnerability and defining the required quality standards. Thus, schematic tools, able to characterise the quality and quantity of groundwater systems, are of very great interest in any territorial planning and/or water resource management activity.This paper proposes a groundwater quality classification method which has been applied to a real aquifer, starting from several studies published by the Italian National Hydrogeologic Catastrophe Defence Group (GNDCI).The methodology is based on the concentration values of several parameters used as indexes of the natural hydro-chemical water condition and of potential man-induced modifications of groundwater quality. The resulting maps, although representative of the quality, do not include any information on its evolution in time. In this paper, this “stationary” classification method has been improved by crossing the quality classes with three indexes of temporal behaviour during recent years. It was then applied to data from monitoring campaigns, performed in spring and autumn, from 1990 to 1996, in the plain of Modena aquifer (central Italy). The results are reported in the form of space-time classification table and maps.     

Evaluation of organic contamination in urban groundwater surrounding a municipal landfill, Zhoukou, China

This paper investigates the organic pollution status of shallow aquifer sediments and groundwater around Zhoukou landfill. Chlorinated aliphatic hydrocarbons, monocylic aromatic hydrocarbons, halogenated aromatic hydrocarbons, organochlorine pesticides and other pesticides, and polycyclic aromatic hydrocarbons (PAHs) have been detected in some water samples. Among the detected eleven PAHs, phenanthrene, fluorine, and fluoranthene are the three dominant in most of the groundwater samples. Analysis of groundwater samples around the landfill revealed concentrations of PAHs ranging from not detected to 2.19 μg/L. The results show that sediments below the waste dump were low in pollution, and the shallow aquifer, at a depth of 18–30 m, was heavily contaminated, particularly during the wet season. An oval-shaped pollution halo has formed, spanning 3 km from west to east and 2 km from south to north, and mainly occurs in groundwater depths of 2–4 m. For PAH source identification, both diagnostic ratios of selected PAHs and principal component analysis were studied, suggesting mixed sources of pyro- and petrogenic derived PAHs in the Zhoukou landfill. Groundwater table fluctuations play an important role in the distribution of organic pollutants within the shallow aquifer. A conceptual model of leachate migration in the Quaternary aquifers surrounding the Zhoukou landfill has been developed to describe the contamination processes based on the major contaminant (PAHs). The groundwater zone contaminated by leachate has been identified surrounding the landfill.     

Assessment of Pollution Near Landfill Site in Nagpur, India by Resistivity Imaging and GPR

Groundwater pollution in the vicinity of a landfill site in Nagpur, India is assessed with the help of resistivity imaging and GPR tools. The resistivity imaging survey indicates high conductive anomalies in the topsoil as well as the underlying fractured rocks. Significant reflections from the GPR records known as radargrams are extracted with the help of maximum peak module and Hilbert transform module in RADAN 6. These reflections can be attributed to presence of fractures, which are potential pathways for migration of the fluid. The geophysical findings are strengthened by the results of groundwater analysis from wells located close to the profile where resistivity and GPR survey have been carried out. The study has indicated the vulnerability of the unconfined aquifer underlying the predominantly clay layer.     

Using GA-Ridge regression to select hydro-geological parameters influencing groundwater pollution vulnerability

For groundwater conservation and management, it is important to accurately assess groundwater pollution vulnerability. This study proposed an integrated model using ridge regression and a genetic algorithm (GA) to effectively select the major hydro-geological parameters influencing groundwater pollution vulnerability in an aquifer. The GA-Ridge regression method determined that depth to water, net recharge, topography, and the impact of vadose zone media were the hydro-geological parameters that influenced trichloroethene pollution vulnerability in a Korean aquifer. When using these selected hydro-geological parameters, the accuracy was improved for various statistical nonlinear and artificial intelligence (AI) techniques, such as multinomial logistic regression, decision trees, artificial neural networks, and case-based reasoning. These results provide a proof of concept that the GA-Ridge regression is effective at determining influential hydro-geological parameters for the pollution vulnerability of an aquifer, and in turn, improves the AI performance in assessing groundwater pollution vulnerability.     

Hydrochemical Changes Over Time in the Zahedan Aquifer, Iran

Groundwater in the Zahedan Aquifer located in the arid southeast of Iran was chemically characterized to understand both the nature of the alluvium aquifer and the effect of human activities, specifically sewage disposal on groundwater quality. Concentrations of major cations and anions in the Zahedan Aquifer are much higher than concentrations observed in groundwater of similar settings. Although the nature of the aquifer and climatic parameters have affected the chemistry of groundwater, human impacts on the groundwater quality are more significant. The electrical conductivity in some areas of the Zahedan aquifer increased up to 7,500μS/cm in 25 years. Human influences in some areas are so prevalent, that the groundwater type changed from a Na⁺-HCO₃ ^- in 1976 to a Na⁺-Cl^- type in 2000. The impact of human influences on the groundwater quality is also indicated through observed nitrate concentration up to 4.81 meq/L in the urban area.