摘要
地下水中污染物具有迁移性和扩散性,会对下游敏感受体造成威胁,目前场地地下水风险评估主要关注人体健康风险,还未能综合考虑地下水污染的整体风险,尤其是忽视了污染物迁移引起的对下游敏感受体的风险。本研究基于“源-径-汇”模型构建了考虑污染物扩散风险的场地地下水污染风险评估的指标体系与风险评估模式。在指标体系构建方面,重点考虑场地地下水的污染源、迁移路径和敏感受体3个方面。在风险评估模式方面,根据场地不同地下水污染状态开展3个层次的风险评估。基于假想的铬污染场地开展了案例分析,设置了地下水污染状态的4种情景,利用Wexler溶质运移模型计算了地下水污染羽的时空变化,并针对地下水污染的不同层次开展了风险评估。结果表明,在场地地下水污染羽未到达场地边界的2种情形中,场地地下水的风险评分分别为4.0,6.2,分别属于低风险与中风险。在场地地下水污染羽到达或超出场地边界的2种情形中,场地地下水的风险评分分别为7.0,8.8,分别属于中风险与高风险。综合而言,本研究构建的方法能够用来对场地地下水进行系统全面的评估和对比,能够根据风险结果对污染场地进行有效的分级管控,为污染场地的风险管控提供技术支撑。
Contaminants in groundwater can spread downstream, causing risks to receptors along the path. The risk assessment of our current site groundwater contamination focuses mainly on human health risks. It rarely considers integrated risks of groundwater contamination, particularly neglecting risks to recepters at downstream locations. This study constructs a new index system and a tiered risk assessment approach for site groundwater contamination based on the “source-pathway-receptor” model considering risks to downstream receptors. For the construction of the index system, the source, pathway and receptor of site groundwater contamination are considered. For the risk assessment approach, a multi-tiered risk assessment are determined according to site groundwater contamination status. Based on the hypothetical case study of a chromium-contaminated site, four scenarios of groundwater contamination states are set. The spatio-temporal changes of groundwater contamination plumes are calculated by using the Wexler solute transport model, and risk assessment is carried out for different states of the groundwater contamination. The results show that in the two cases where the site groundwater contamination plumes have not reached the site boundary, the risk scores of the site groundwater are 4 and 6.2points, respectively. The risk of the site groundwater at the two contamination states is low and medium,respectively. In the two cases where the site groundwater contamination plumes have arrived or exceeded the site boundary, the risk scores of the site groundwater are 7.0 and 8.8 points, respectively. The corresponding risk at the two contamination states is medium and high, respectively. It can be seen that this new method can comprehensively assess the potential level of harm of groundwater contamination to both human health and ecological environment, and therefore can provide technical support for the management of contaminated sites.
作者
张行洲
殷乐宜
陈坚
周笑笑
杨丽虎
吴吉春
谢月清
ZHANG Xingzhou;YIN Leyi;CHEN Jian;ZHOU Xiaoxiao;YANG Lihu;WU Jichun;XIE Yueqing(Key Laboratory of Earth Surficial Geochemistry of Ministry of Education,School of Earth Sciences and Engineering,Nanjing University,Nanjing,Jiangsu 210023,China;Ecological Environment Joint Research Center for Yangtze River Economic Zone,Chinese Academy for Environmental Planning,Beijing,100012,China;Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing,100101,China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2023年第2期160-170,共11页
Hydrogeology & Engineering Geology
基金
国家重点研发课题(2019YFC1804803)。
关键词
场地地下水污染
“源-径-汇”模型
指标体系
风险评估
site groundwater contamination
source-pathway-receptor model
index system
risk assessment
