Chen Li-Wei, Xu Xiao-Chun, Wang Jun, Chen Fang
Huan Jing Ke Xue. 2014 Aug;35(8):2967-73.
The Xiangsi River valley was selected to study the distribution of heavy metals in mining area. Waste rocks, soils, sediments and waters of Xiangsi River valley were sampled. The concentrations of Cu, Pb, Zn, Cd, Cr, As and Hg were analyzed. The possibility of generating acid drainage of the waste rocks was studied. Meanwhile, the speciation of Pb and Cr in waste rocks was analyzed by the five-step sequential chemical extract method developed by Fŏrtsner. And then the distribution of heavy metals in various samples was summarized, and the ecological risk of heavy metals in mining area was discussed. The results indicated that the waste rocks of Fenghuangshan copper mine upriver barely generated acid mine drainage (AMD). But the waste rocks of Xinqiao pyrite mine in the middle area generated AMD. The content of sulfide mineral rich of heavy metals was lower and the content of CaO was higher in the waste rocks of Fenghuangshan copper mine, resulting in the different AMD generation ability. The contents of heavy metals in waste rocks were higher, and the deoxidization of Pb and Cr was positively correlated with their concentrations in waste rocks. The results indicated that heavy metals in waste rocks would be most likely dissolved in AMD and then contaminate the environment. There was obvious regularity in the distributions of heavy metals in soils, sediments and waters of Xiangsi river valley. The concentrations of heavy metals upriver were lower than those of corresponding national standards and elements background values. But there was obvious heavy metal contamination in the middle area. It was shown that the mining activities of Xinqiao pyrite mine in the middle area had ecological harm to the surrounding environment. And mining enterprises should pay attention to the emissions of mining wastes and the treatment of AMD.
选取相思河流域研究矿区重金属分布情况。采集了相思河流域的废石、土壤、沉积物和水体样本。分析了铜、铅、锌、镉、铬、砷和汞的浓度。研究了废石产生酸性排水的可能性。同时，采用Fŏrtsner开发的五步连续化学提取法分析了废石中铅和铬的形态。然后总结了各种样品中重金属的分布情况，并探讨了矿区重金属的生态风险。结果表明，上游凤凰山铜矿的废石几乎不产生酸性矿山排水（AMD）。但中部新桥硫铁矿的废石产生了AMD。凤凰山铜矿废石中富含重金属的硫化物矿物含量较低，氧化钙含量较高，导致其产生AMD的能力不同。废石中重金属含量较高，铅和铬的还原与它们在废石中的浓度呈正相关。结果表明，废石中的重金属很可能溶解在AMD中，进而污染环境。相思河流域土壤、沉积物和水体中重金属的分布具有明显的规律性。上游重金属浓度低于相应的国家标准和元素背景值。但中部存在明显的重金属污染。结果表明，中部新桥硫铁矿的开采活动对周边环境造成了生态危害。采矿企业应注意采矿废弃物的排放和AMD的处理。
