摘要
对我国北方某城市的浅层地下水进行了有机污染调查 ,局部地区发现了严重的氯代烃污染 .PCE和TCE对地下水的污染程度远远大于CF和CT ,是主要污染物 ,最高浓度分别为 4 87 .5 5 μg/L和 6 3 .74 μg/L .本文根据所掌握的资料 ,结合氯代烃天然条件下生物降解判定方法 ,对研究区地下水氯代烃生物降解衰减可能性进行研究 .结果表明 ,该市地下水氯代烃污染区浅层地下水环境、Eh、pH值、生物降解的间接标志NO-3 浓度变化 ,以及PCE和TCE生物降解中间产物等均有助于证实氯代烃生物降解转化的存在 .多数点为Eh小于 10 0mV的还原环境 ,将综合污染评价分级中 1、2级 ,3、4级和 5级所对应的NO-3 /Cl-值求平均分别为 0 . 80 4 ,0 . 75 4和 0 . 5 96 ,在所有检出DCE的点中 ,cis 1,2 DCE的百分比均超过了DCE总量的 80 % .室内模拟实验进一步说明 ,氯代烃污染区地下水环境中 ,氯代烃完全可能产生共代谢生物降解转化 ,因此 ,确认PCE存在向TCE的生物降解转化 ,能够更加合理地解释这一地区TCE和PCE的污染现状 .
Chlorinated solvents contaminations are most popular in shallow groundwater. A serious local groundwater contamination of chlorinated solvents is founded in a north city of China during the organic pollution investigation. On the basis of the available data and the determining methods of chlorinated solvents biodegradation in groundwater under natural conditions, research on chlorinated solvents biodegrading potential is carried out. The results show that the ground water environment parameters, Eh and pH of the groundwater, indirect sign of biodegradation, i.e. NO-_3 changing, and concentration variation of biodegradation intermediate products of PCE and TCE all proved that chlorinated solvents can be degraded by microorganism in groundwater. The results of simulating experiment also reveal that, co-metabolism biodegradation of chlorinated solvent was possible under the groundwater circumstances in this sample. Therefore, admitting there is biotransformation from PCE to TCE can explain the present situation more reasonably.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2005年第2期121-125,共5页
Environmental Science
基金
国家自然科学基金项目 (4 0 3 72 10 9)
海外青年学者合作研究基金项目 (4 0 2 2 80 0 4) .
关键词
氯代烃
天然衰减
生物降解
浅层地下水
chlorinated solvents
natural attenuation
biodegradation
shallow groundwater
