The water that is released after domestic and industrial usage is highly contaminated with heavy metals and other impurities which becomes lethal to human health if left untreated. Henceforth the industrial and domestic effluents are analysed for various physical, chemical parameters along with presence of heavy metals. Once analysed with high concentration of any specific heavy metal, it is treated using micro-organism. In the present study of this book, heavy metal that was analysed is hexavalent chromium. And the remediation of waste water containing chromium was done using Acidthiobacillus ferroxidans species. The degree of reduction of hexavalent chromium in the different industrial waste water samples was studied.