Immobilization of arsenic using acidophilic, iron-oxidizing archaeon

铁榴石（FeAsO4•2H2O）是一种热力学稳定的矿物，具有作为砷处理化合物的优势。为了固定化铜精炼工艺溶液中含有的剧毒As(III)，最终以结晶铁长石的形式存在，研究了利用嗜热酸性铁氧化古菌Acidianus brierleyi的方法。酵母浸膏上的微生物生长有利于细胞表面的Fe（III）氧化As（III）。酵母提取物存在下，初始Fe(II)/As（III）比为1.4时，两种离子都容易氧化，86-100%的As析出为结晶的铁球石。微生物氧化Fe（II）和As（III）的摩尔比是决定次生矿物形成类型的重要因素。本研究证明了一步生物工艺的适用性，该工艺可以通过生产生物源结晶铁球石来处理含As（III）的铜精炼厂工艺溶液。

Scorodite (FeAsO4•2H2O) is a thermodynamically stable mineral with advantages as an arsenic disposal compound. With an aim to immobilize highly toxic As(III) contained in the copper refinery process solution, eventually in the form of crystalline scorodite, the use of thermo-acidophilic iron-oxidizing archaeon, Acidianus brierleyi, was investigated. Microbial growth on yeast extract was implied to facilitate As(III) oxidation by Fe(III) on cell surface. When the initial Fe(II)/As(III) ratio was set at 1.4 in the presence of yeast extract, both ions were readily oxidized and 86-100% of As was precipitated as crystalline scorodite. The molar ratio of microbially-oxidized Fe(II) and As(III) was an important factor to determine the type of the secondary mineral formed. This study demonstrates the applicability of an one-step bioprocess which enables treatment of As(III)-bearing copper refinery process solution by producing biogenic crystalline scorodite.