Tabak Henry H, Scharp Richard, Burckle John, Kawahara Fred K, Govind Rakesh
US Environmental Protection Agency, ORD, NRMRL, Cincinnati, OH 45268, USA.
Biodegradation. 2003 Dec;14(6):423-36. doi: 10.1023/a:1027332902740.
Acid mine drainage (AMD), an acidic metal-bearing wastewater, poses a severe pollution problem attributed to post mining activities. The metals usually encountered in AMD and considered of concern for risk assessment are arsenic, cadmium, iron, lead, manganese, zinc, copper and sulfate. The pollution generated by abandoned mining activities in the area of Butte, Montana has resulted in the designation of the Silver Bow Creek-Butte Area as the largest Superfund (National Priorities List) site in the U.S. This paper reports the results of bench-scale studies conducted to develop a resource recovery based remediation process for the clean up of the Berkeley Pit. The process utilizes selective, sequential precipitation (SSP) of metals as hydroxides and sulfides, such as copper, zinc, aluminum, iron and manganese, from the Berkeley Pit AMD for their removal from the water in a form suitable for additional processing into marketable precipitates and pigments. The metal biorecovery and recycle process is based on complete separation of the biological sulfate reduction step and the metal precipitation step. Hydrogen sulfide produced in the SRB bioreactor systems is used in the precipitation step to form insoluble metal sulfides. The average metal recoveries using the SSP process were as follows: aluminum (as hydroxide) 99.8%, cadmium (as sulfide) 99.7%, cobalt (as sulfide) 99.1% copper (as sulfide) 99.8%, ferrous iron (sulfide) 97.1%, manganese (as sulfide) 87.4%, nickel (as sulfide) 47.8%, and zinc (as sulfide) 100%. The average precipitate purity for metals, copper sulfide, ferric hydroxide, zinc sulfide, aluminum hydroxide and manganese sulfide were: 92.4, 81.5, 97.8, 95.6, 92.1 and 75.0%, respectively. The final produced water contained only calcium and magnesium and both sulfate and sulfide concentrations were below usable water limits. Water quality of this agriculturally usable water met the EPA's gold standard criterion.
酸性矿山排水（AMD）是一种含酸性金属的废水，由于采矿后的活动而造成严重的污染问题。在AMD中通常会遇到且在风险评估中被视为关注对象的金属有砷、镉、铁、铅、锰、锌、铜和硫酸盐。蒙大拿州比尤特地区废弃采矿活动产生的污染导致银弓溪 - 比尤特地区被指定为美国最大的超级基金（国家优先事项清单）场地。本文报告了为开发一种基于资源回收的修复工艺以清理伯克利矿坑而进行的实验室规模研究的结果。该工艺利用金属以氢氧化物和硫化物（如铜、锌、铝、铁和锰）的形式进行选择性顺序沉淀（SSP），从伯克利矿坑AMD中去除这些金属，使其以适合进一步加工成可销售沉淀物和颜料的形式从水中分离出来。金属生物回收和循环利用工艺基于生物硫酸盐还原步骤和金属沉淀步骤的完全分离。在SRB生物反应器系统中产生的硫化氢用于沉淀步骤以形成不溶性金属硫化物。使用SSP工艺的平均金属回收率如下：铝（以氢氧化物形式）99.8%，镉（以硫化物形式）99.7%，钴（以硫化物形式）99.1%，铜（以硫化物形式）99.8%，亚铁（硫化物）97.1%，锰（以硫化物形式）87.4%，镍（以硫化物形式）47.8%，锌（以硫化物形式）100%。金属硫化铜、氢氧化铁、硫化锌、氢氧化铝和硫化锰的平均沉淀物纯度分别为：92.4%、81.5%、97.8%、95.6%、92.1%和75.0%。最终产生的水中仅含有钙和镁，硫酸盐和硫化物浓度均低于可用水限值。这种农业可用水的水质符合美国环保署的黄金标准准则。
