Absorption of Chromium and Nickel From Aqueous Solu-tion by Bacteria Isolated From Electroplating Unit Effluent

摘要

Heavy metals are valuable resources for different industrial applications but their contamination in environment is of major global concern. Strict environmental regulations compel the industries to shift to cleaner production method, demanding the development of environmental friendly, low cost and efficient treatment techniques for metal rich effluent. Microorganisms can remove heavy metals by the process of bioaccumulation which is cost effective and eco-friendly as compared to conventional methods. The present study was carried out on bacterial isolates from electroplating unit effluent to check their potential for removal of chromium and nickel from aqueous solution containing single heavy metal. A special staining method was used to observe the concentration of metals within the cells. Growth study of the bacterial isolates showed that the toxicity of metals in medium could not support the growth of bacteria. Upto 38.3% and 40.0% removal of nickel and upto 64.0% and 69.0% removal of chromium in nutrient medium and minimal media, respectively was observed using bacterial isolates. Hence, it can be concluded that the bioaccumulation is efficient and cost effective eco-friendly process and the isolated bacterial strains, which can tolerate high concentration of heavy metals, can be utilized for metal recovery process.