地下水微量有机污染

MICROORGANIC POLLUTION OF GROUNDWATER

在简要评述其污染特征与研究特点的基础上，总结介绍了地下水微量有机污染的分布，污染物种类、性质、危害和来源，有机物的物化特征及其在环境中的迁移转化，以及污染控制技术。非极性难溶挥发性有机物（ＶＯＣ＇ｓ）是地下水中危害最大而又最为常见的有机污染物，主要由氯代脂肪烃（ＣＨＣ）和单环芳香烃（ＢＴＥＸ）构成。多数水溶相ＶＯＣ＇ｓ不易被吸附，在地下环境具有很强的迁移性，但在适当条件下可生物降解。非水溶相ＣＨＣ常在地下水中积聚潜伏于含水层底板，迁移不受地下水流向的控制；非水溶相ＢＴＥＸ则漂浮于地下水表面。非水溶相ＶＯＣ＇ｓ很难产生生物降解。ＶＯＣ＇ｓ的去除过程复杂，许多领域有待探索。

On brief review of the literature on organic pollution of groundwater, a systematic summary in this field is presented, including distribution of the pollution, nature,toxicological effects. sources and classification of organic contaminants, and their mobilityas well as transformation in the vadose zone and groundwater. It is concluded that volatileorganic compounds (VOC's) are the most frequently detected groundwater contaminants,such as chlorinated aliphatic hydrocarbons (CHC) and aromatic hydrocarbons (BTEX).At concentrations below their water solubility limit, VOC's will dissolve in groundwaterand be biodegradable. However due to their low water solubility and densities greater thanwater, CHCs often accumulate as free-phase chemicals above a low permeability stratumand move downslope under gravitational pull. regardless of ground-water flow direction.These non-aqueous liquids are not biodegradable. VOC's control is very complex. Technical tools to manage groundwater quality need to be developed.