Microbial remediation of chromium-contaminated wastes

Cr(VI) and Cr(III) are the two most ubiquitous forms of chromium. The remediation of chromium contaminant is primarily dependent on transformation from highly toxic and mobile Cr(VI) to insoluble Cr(III) with less toxicity. Biological Cr(VI) removal is not only a promising method but also a very complicated process. This chapter introduces various remediation processes, highlights important Cr(VI)-reducing microorganisms, and reveals underlying mechanisms for bacterial Cr(VI) resistance and reduction. The assessment of key factors limiting and influencing bacterial growth and chromium removal along with reviews on mathematical modeling tended to facilitate further application of microbial Cr(VI) removal in the bench scale, pilot scale, and in situ studies under a wide array of environmental conditions