Isolation of Hexavalent Chromium Reducing Bacteria from Paint Factory Effluent and Introducing the Appropriate Strain to Remove Hexavalent Chromium from Aqueous Solution

Heavy metals are a group of metals have a density of ۵ g/cm۳ or more. In recent years, with the increase in industrialization, the production rate of industrial effluents containing heavy metals has increased, which is rapidly discharging into the environment and affecting the lives of organisms. Industrial effluents such as dyeing, photography, pigment manufacturing, electroplating, leather tanning, wood preservation, and alloy production contain chromium. One of the most serious environmental problems today is finding a way to remove heavy metals from the environment. Chromium is one of the most toxic heavy metals that has many destructive effects on human health. Chromium exists in two stable forms in the environment, Cr(VI) and Cr(III). Hexavalent chromium is more toxic and destructive and it is soluble in water. Trivalent chromium is less toxic and insoluble in water. Various methods can be used to remove hexavalent chromium or reduce it to trivalent chromium. Using biological methods for this purpose is a good solution because in addition to being inexpensive, it is an environmentally friendly method. In this study, bacteria in the effluent of a paint factory were isolated and used to remove hexavalent chromium. ۳۸ different strains were obtained. Among the isolated bacteria, one strain with the ability to remove ۵۲.۰۱% Cr(VI) within ۷ days was identified and introduced.

Keywords:

Bioremoval , hexavalent chromium , microorganism , bacteria