Immobilization of arsenic using acidophilic, iron-oxidizing archaeon

蝎子石(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点。为了固定铜精炼过程溶液中的剧毒As(III)，最终以结晶蝎子的形式存在，研究了高温酸性铁氧化古生菌Acidianus brierleyi的使用。酵母抽提物上的微生物生长促进了细胞表面Fe(III)对As(III)的氧化。在酵母膏存在下，当Fe(II)/As(III)的初始比为1.4时，这两种离子都很容易被氧化，86-100%的As以结晶蝎子的形式析出。微生物氧化Fe(II)和As(III)的摩尔比是决定次生矿物类型的重要因素。这项研究证明了一步生物法的适用性，该生物法能够通过产生生物结晶蝎子石来处理含As(III)的铜精炼工艺溶液。

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.