地下水中重金属污染来源及研究方法综析

Source and Research Status of Heavy Metal Pollution in Groundwater: A Review

查明重金属污染来源是地下水重金属污染防治的前提。近年来随着我国城市化进程的加快和工业的迅猛发展,我国地下水重金属污染也呈现日益严重的趋势。地下水重金属污染来源可分为自然来源和人为来源。地下水重金属污染的来源主要是人为来源,主要包括工业生产、再生水灌溉和生活污染来源。地下水重金属的工业污染主要位于重金属矿山和工业城市附近,其特点是污染元素种类多、浓度高,一般生产历史越长,重金属污染越严重。再生水重金属污染主要位于北方缺水区,运用再生水灌溉首先应该对再生水的重金属污染进行评价。生活来源的重金属污染对地下水正施加着愈来愈重要的影响,当前城市垃圾渗滤液正在成为地下水重金属污染的新源头。根据地下水重金属污染的空间分布、含水层对比、主成分分析、稳定同位素示踪及多元混合模型多种方法手段综合分析,客观准确地判断地下水重金属污染的来源及比例,制定科学合理地下水重金属污染的治理方案,以达到最佳的治理效果。

Understanding the source of heavy metals in groundwater is the precondition for prevention and remediation of heavy metal pollution in groundwater. In recent years,with the acceleration of urbanization and the rapid development of industry,the heavy metal pollution of groundwater in China is becoming more and more serious. The sources of heavy metals in groundwater can be divided into two categories,natural and anthropogenic sources. Heavy metals in groundwater are mainly from the anthropogenic source,including industrial production,reclaimed water irrigation and urban household waste. The industrial pollution sources of heavy metals,usually characterized by multiple elements coexisting with relatively high concentrations,in groundwater are mainly located near heavy metal mines and industrial cities. Generally,the longer is the production history,the more serious is the heavy metal pollution. The heavy metal pollution from using reclaimed water happens mainly in the north,the area of water shortage. The reclaimed water should be evaluated before using for irrigation. The urban household waste exerts increasing influence on heavy metal pollution in groundwater and the urban landfill leachate has become a new source of heavy metals to groundwater. A comprehensive analysis method based on spatial distribution of heavy metals in groundwater,comparison of aquifers,principal component analysis,stable isotope tracing and multivariate hybrid model has great importance not only to distinguish sources and apportion their contributions objectively and accurately but also to establish a scientific and reasonable management plan for heavy metal pollution in groundwater.