A combined bacterial process for the reduction and immobilization of chromium

Abstract

In this paper, we present the indirect Cr(VI) reduction by Acidithiobacillus thiooxidans using sulfur as energy source under aerobic conditions and the subsequent Cr(III) precipitation by Desulfovibrio sp. under anaerobic conditions. Cr(VI) reduction is promoted by intermediate-products such as sulfite and thiosulfate. Both processes have been operated sequentially under continuous flow conditions to decontaminate a 5 mg l-1 Cr(VI) solution.