环境化学
李志萍,陈肖刚,沈照理.污染河流中Cr(Ⅵ)对浅层地下水的影响研究[J].环境科学学报,2006,26(1):99-104
污染河流中Cr(Ⅵ)对浅层地下水的影响研究
- Influence on shallow ground water by chromium in polluted river
- 基金项目:国家重点基础研究发展规划项目(No.G1999045706);华北水利水电学院青年科研基金项目(No.HSQJ2004005)
- 李志萍
- 华北水利水电学院岩土工程系, 郑州 450008
- 陈肖刚
- 华北水利水电学院岩土工程系, 郑州 450008
- 沈照理
- 中国地质大学水资源与环境学院, 北京 100083
- 摘要:为了研究污染河流中Cr(Ⅵ)对浅层地下水的影响,选用3种天然砂土作为渗透介质进行室内试验,以生活污水模拟污染河水,发现铬在粗砂中第13d发生穿透,此后粗砂对铬的去除率为77%~99%;2种中砂对铬的去除率始终大于91%和96%,铬很难进入地下水.凉水河野外试验表明,凉水河沿岸的1#、2#、3#采样点和煤厂井中Cr(Ⅵ)浓度均不大于地下水中Cr(Ⅵ)的背景浓度,凉水河中的Cr(Ⅵ)对地下水影响较小.还原和沉淀反应是Cr(Ⅵ)去除的主要机理,由于长期污染河流下部渗透介质始终处于厌氧环境,其中富含还原性物质,Cr(Ⅵ)可以通过沉淀反应大部分得以去除,本次试验研究表明污染河流不是地下水铬污染的来源.
- Abstract:In order to study the influence on shallow ground water by Cr(Ⅵ) in polluted river, in the lab-scale experiment three kinds of natural sand were chosen as infiltration medium, and polluted rivers were simulated by domestic sewage, it was found that Cr(Ⅵ) penetrated on the 13th day and then had a removal ratio of 77%~99% in coarse sand, over 91% and 96% in two kinds of medium sand. It was difficult for Cr(Ⅵ) to enter ground water. In on-site test it was indicated that the concentration of Cr(Ⅵ) in 1#,2#,3#and coal yard well along the bank of Liangshui River was not greater than background concentration in groundwater, so Cr(Ⅵ)in Liangshui River had a little influence on ground water. The mechanism of Cr(Ⅵ) removal was reducing action and sedimentation. Cr(Ⅵ)mainly was transformed to precipitation by reducing action because of abundant reduction agent in the infiltration media, so the tests indicated that polluted river was not the source of Cr(Ⅵ)pollution in ground water.