Comparative assessment of heavy metal removal by immobilized and dead bacterial cells: A biosorption approach

摘要

Microorganisms play a vital role in heavy metal contaminated soil and wastewaterby the mechanisms of biosorption. In this study, heavy metal resistant bacteria were isolated from an electroplating industrial effluent samples that uses copper, cadmium and lead for plating. These isolates were characterized to evaluate their applicability for heavy metal removal from industrial wastewaters. The physico-chemical parameters of the samples were initially analyzed. The optimum conditions of pH, biomass concen-tration and heavy metal concentration were determined for the microbial growth on biosorbents and correlated with heavy metal removal. The observed optimum conditions were applied for the biosorption process carried out in immobilized and dead bacterial isolates.The biosorption of immobilized cells ofBacillussp. was 69.34% of Cu,Pseudomonassp. was 90.41% of Cd andMicrococcussp. was 84.27% of Pb, whereas the dead cells ofBacillussp. was 44.73% of Cu,Pseudomonassp. was 86.66% of Cd andMicrococcussp. was 79.22%. Experimental results reveal that all the immobilized isolates have potential application for the removal of Cu, Cd and Pb from industrial wastewater than the dead bacterial cells.