Reduction of hexavalent chromium to trivalent chromium from tannery effluent using bacterial biomass

Abstract

Bioremediation is the most promising and cost-effective biological method widely used to clean up both contaminated soil and wastewater containing organic and inorganic pollutants. Ambur in Tamil Nadu is included in top ten Cr (VI) contaminated placeS in the world rated by Blacksmith Institute, U.S., in September 2006. Cr (VI) pollution in this area causes major health issues among the settled people, destruction of waterbodies, and pollutes the groundwater and agricultural lands. This work involves the biological treatment of Cr (VI) without producing any by-product. Bacterial culture tolerating high concentration isolated from the contaminated soil samples was collected from Cr (VI) contaminated sites of Ambur. The bacterial isolate was identified as 16s rRNA sequencing for Pseudomonasputida. Under the optimum parameter condition, reduction of Cr (VI) by isolated Pseudomonas putida was found to be 90% and Cr (VI) reduction by consortium of microbe to be 92%. Finally, reduced chromium was separated from the tannery effluent by chemical precipitation method.