Hydrogeochemical and mineralogical characteristics related to heavy metal attenuation in a stream polluted by acid mine drainage: A case study in Dabaoshan Mine, China

详细信息	查看全文 | 推荐本文 |

• 作者：Huarong Zhao^a ; ^b ; Beicheng Xia^a ; ^{xiabch@mail.sysu.edu.cn} ; Jianqiao Qin^c ; Jiaying Zhang^a
• 关键词：acid mine drainage ; Dabaoshan Mine ; heavy metal attenuation ; hydrogeochemical ; PHREEQC
• 刊名：Journal of Environmental Sciences
• 出版年：2012
• 期刊代码：8_10010742
• 类别：env
• 出版时间：June, 2012
• 卷：24
• 期：6
• 页码：979-989
• 文件大小：634 K

摘要

Dabaoshan Mine, the largest mine in south China, has been developed since the 1970s. Acid mine drainage (AMD) discharged from the mine has caused severe environmental pollution and human health problems. In this article, chemical characteristics, mineralogy of ocher precipitations and heavy metal attenuation in the AMD are discussed based on physicochemical analysis, mineral analysis, sequential extraction experiments and hydrogeochemistry. The AMD chemical characteristics were determined from the initial water composition, water-rock interactions and dissolved sulfide minerals in the mine tailings. The waters, affected and unaffected by AMD, were Ca-SO₄ and Ca-HCO₃ types, respectively. The affected water had a low pH, high SO₄^{2鈭?/sup> and high heavy metal content and oxidation as determined by the Fe2+/Fe3+ couple. Heavy metal and SO₄2鈭?/sup> contents of Hengshi River water decreased, while pH increased, downstream. Schwertmannite was the major mineral at the waste dump, while goethite and quartz were dominant at the tailings dam and streambed. Schwertmannite was transformed into goethite at the tailings dam and streambed. The sulfate ions of the secondary minerals changed from bidentate- to monodentate-complexes downstream. Fe-Mn oxide phases of Zn, Cd and Pb in sediments increased downstream. However, organic matter complexes of Cu in sediments increased further away from the tailings. Fe3+ mineral precipitates and transformations controlled the AMD water chemistry.}