Zhou Yue-Fei, Xie Yue, Zhou Li-Xiang
Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Huan Jing Ke Xue. 2010 Jun;31(6):1581-8.
Acid mine drainage (AMD) and its natural neutralizing products in Wangjiatan iron mine were collected and analyzed by using spectroscopic and electron microanalytic methods. The results show that after natural neutralization of AMD by surface water of the stream, acidity and electric conductivity of AMD are both decreased. While for dissolved elements, no other element is obviously decreased except for Fe3+, SO4(2-), and Ca2+. For precipitates formed by natural neutralization, Fe is enriched and ferrihydrite is the main iron mineral, with little amount of goethite and fibroferrite contained in downstream precipitates. To ferrihydrite, 2-line and 6-line ferrihydrite are the main mineral type in upstream and downstream precipitates, respectively. Furthermore, for all precipitates, two layers are observed. In outer layer 2-line ferrihydrite is the main mineral, while in inner layer 6-line ferrihydrite and goethite are the main minerals. Ferrihydrite dominated precipitates are favorable in immobilizing toxic and hazardous elements. Furthermore, it is demonstrated that pH and the concentration of SO4(2-) are decisive factors for ferrihydrite formation. The ferrihydrite translocation and its attenuation for toxic elements are, to a great extent, affected by hydrodynamics in neutralization zone.
采集了王家滩铁矿的酸性矿山废水（AMD）及其天然中和产物，采用光谱和电子显微分析方法进行了分析。结果表明，AMD经溪流水体自然中和后，酸度和电导率均降低。对于溶解元素，除Fe3+、SO4(2-)和Ca2+外，其他元素无明显降低。对于自然中和形成的沉淀物，Fe富集，水铁矿是主要的铁矿物，下游沉淀物中含有少量针铁矿和纤铁矿。对于水铁矿，2线水铁矿和6线水铁矿分别是上游和下游沉淀物中的主要矿物类型。此外，对于所有沉淀物，均观察到两层。外层主要矿物为2线水铁矿，而内层主要矿物为6线水铁矿和针铁矿。以水铁矿为主的沉淀物有利于固定有毒有害元素。此外，研究表明pH值和SO4(2-)浓度是水铁矿形成的决定性因素。水铁矿的迁移及其对有毒元素的衰减在很大程度上受中和区水动力的影响。
