Biosorption of hexavalent chromium by microorganisms

Microorganisms perform an important function in the bioremediation of contaminated soils, water and effluents. Bacteria, fungi, yeasts and microalgae and cyanobacteria, are low-cost biotechnological tools for the treatment of large volumes of complex effluents containing Cr(VI). As from the selection and identification of new microorganisms and the evolution of Modern Biotechnology, molecular techniques and the characteristics of microorganisms such as their versatility and capacity to adapt to different environments, permit that the biosorption of Cr(VI) be an alternative for the removal of contaminants. Variations in the cell composition, morphology and way of growth, as also a study of the operational conditions, allow for the application of aerobic or anaerobic microorganisms, live or dead, in the removal of Cr(VI). Thus the characteristics of the biosorbents applied in the removal of Cr(VI), the biosorption processes, reactors and bioreactors, and the research developed with a view to the biosorption will be discussed in this review. (C) 2016 Elsevier Ltd. All rights reserved.