Development of Microbial Consortium for Removal of Heavy Metals from Electroplating Industries Effluent

Abstract

Heavy metals have become a serious threat to the biosphere, due to natural and anthropogenic causes. Rapid and consistent industrialization processes are mainly responsible for the release of heavy metals into the environment. Mobility and transport of such heavy metals occur mainly through aquatic means. The toxicity of heavy metals is depending on their concentrations and their chemical species. At high concentrations than the threshold level, heavy metals are more toxic than present at low concentrations. Heavy metals are persistent and get biomagnified in the food cycle and food web. Heavy metal accumulation in the aquatic ecosystem, agricultural soil leads to serious environmental issues. Electroplating is a widely used process across various industries like stainless steel, automobile, aerospace, and toy products. Effluent from such industries is one of the major heavy metal contamination sources. The effluent of the electroplating industry contains heavy metals like chromium, nickel, copper, zinc, etc. The toxicity of chromium particularly hexavalent chromium is more followed by divalent nickel and copper. Hexavalent chromium has very low discharge limits than a nickel as well as copper. Hexavalent chromium has hardly any biological benefits in comparison with nickel and copper. In lack of proper treatment, disposal of the effluent of electroplating industries become an environmental challenge. Existing physical and chemical practices for the removal of heavy metals are having limitations as they are producing secondary environmental issues. Bioremediation can be used as an alternative to such conventional methods. The bioremediation process is a cost-effective, environmentally friendly process, and use of which can decrease the need for energy as well as additional chemicals required for removal of heavy metals from the environment. Recently nanoparticles are also being used as alternative tools for the removal of heavy metals from industrial wastewater. Many studies have done for the isolation of heavy m