Biological Oxidation of Arsenite in Strong Acid Water

Arsenic occurs mostly as arsenite (As (III)) or arsenate (As (V)) in natural water. As(III) is more difficult to be remove than As(V), and it is necessary to oxidize As(III) to As(V) for effective removal. Arsenite-oxidizing population, named IWAS, was selected from acid mine drainage. IWAS oxidized arsenite to arsenate in the pH range from 2.1 to 1.2. IWAS can gain the energy for the growth through oxidation of As(III) to As(V). In this study, we examined the effects of factors such as organic matter, As(III) concentration and so forth on microbial oxidation of arsenite.