酸性矿山排水对岩溶地下水的影响——基于特征污染物Fe、Mn、As等的对比

Impact of Acid Mine Drainage ( AMD) on Karstic Groundwater——Based on the Comparison of Fe,Mn and As

本文以贵州省兴仁县交乐村猫石头水库下游受酸性矿山废水污染的水体以及岩溶地下水为研究对象,通过当地农田沟渠改道前后水体特征污染物Fe、Mn、As等的变化特征,阐述矿山酸性水体对岩溶地下水水质的影响。结果表明,天然溪沟对酸性矿山水水体的自净明显,而溪流改造工程导致矿山酸性水体快速向下游扩散。受酸性矿山水污染的岩溶地下水经过一系列的水体自我修复作用,污染程度有一定的减缓,但仍高于相应的区域背景值。而沟渠改造切断酸性矿山水与岩溶地下水系统的水力联系后,经过较短时间的地下水体的自我修复,其所有重金属含量均可还原到区域背景值。

The study area, where steam and reservoir are influenced by the erosion of the tailing deposits and the input of acid mine drainage （AMD） from the abandoned coal associated pyrite mines, is located in Jiaole, Xin- gren County, Guizhou Province. Taking the local stream and Karstic groundwater which lies downstream of Mao- shitou reservoir for example, we illustrated the impact of AMD on Karstic groundwater through studying the chan- ging features of the primary typical pollutants such as Fe, Mn and As before and after the diversions of farmland ditches. The result shows that the self-purification capacity of natural stream to AMD is obvious based on the neutralizing effect of carbonate rocks in the karstic area. Instead, the diversions of farmland ditches led to the water which included AMD spreading quickly to downstream. Aider the artificial farmland ditches remade, the hydraulic connection between polluted water and groundwater was broken off. Consequently, the self-purification of Karstic groundwater is positive and obvious, and the concentrations of Fe, Mn and As can fall back to the lev- el of background in the study area.