School of Biological Sciences, College of Natural Sciences, Bangor University , Deiniol Road, Bangor LL57 2UW, United Kingdom.
Environ Sci Technol. 2014 Oct 21;48(20):12206-12. doi: 10.1021/es5030367. Epub 2014 Oct 7.
Mine waters are widely regarded as environmental pollutants, but are also potential sources of valuable metals. Water draining the Maurliden mine (Sweden) is highly acidic (pH 2.3) and rich in zinc (∼ 460 mg L(-1)) and iron (∼ 400 mg L(-1)), and contains smaller concentrations (0.3-49 mg L(-1)) of other transition metals and arsenic. We have developed novel techniques that promote the concurrent amelioration of acidic waste waters and selective recovery of metals, and have used these systems to treat synthetic Maurliden mine water in the laboratory. The two major metals present were removed via controlled biomineralization: zinc as ZnS in a sulfidogenic bioreactor, and iron as schwertmannite by microbial iron oxidation and precipitation of ferric iron. A small proportion (∼ 11%) of the schwertmannite produced was used to remove arsenic as the initial step in the process, and other chalcophilic metals (copper, cadmium and cobalt) were removed (as sulfides) in the stage 1 metal sulfide precipitation reactor. Results from this work have demonstrated that modular biomineralization units can be effective at processing complex mine waters and generating metal products that may be recycled. The economic and environmental benefits of using an integrated biological approach for treating metal-rich mine waters is discussed.
矿山水被广泛认为是环境污染物质，但也是有价值金属的潜在来源。从瑞典 Maurliden 矿排出的水具有很强的酸性（pH 值 2.3），富含锌（约 460mg/L）和铁（约 400mg/L），并且含有其他过渡金属和砷的较小浓度（0.3-49mg/L）。我们开发了促进酸性废水同时改善和选择性回收金属的新技术，并在实验室中使用这些系统处理模拟的 Maurliden 矿山水。两种主要金属通过控制生物矿化去除：在硫化物生物反应器中，锌作为 ZnS；通过微生物铁氧化和铁的沉淀，铁作为水羟铁锰矿。产生的水羟铁锰矿的一小部分（约 11%）用于去除砷，作为该过程的第一步，其他亲硫金属（铜、镉和钴）在第一阶段金属硫化物沉淀反应器中被去除（形成硫化物）。这项工作的结果表明，模块化生物矿化单元可以有效地处理复杂的矿山水，并生成可能被回收的金属产品。讨论了使用集成生物方法处理富含金属的矿山水的经济和环境效益。
