Biosorption of cadmium using a novel bacterium isolated from an electronic industry effluent

Heavy metal clean-up from electronic industry effluents is an important issue to be addressed. In this work, we report for the first time the isolation of a novel bacterial strain of Halomonas from electronic industry effluent and its subsequent utility for the adsorption of cadmium. The microbial community was characterised using various biochemical and molecular techniques. The bacterial surface possessing hydroxyl, carboxyl and amino groups play a vital role in this host guest interaction. Three strains of Halomonas species were isolated from these effluents, among which Halomonas BVR 1 was found to be an excellent host to the divalent cadmium. The influence of various analytical parameters on the adsorption of cadmium was studied in detail. The surface characterization of the adsorbent was done through FT-IR and SEM-EDAX techniques. Adsorption thermodynamics was spontaneous and exothermic. Halomonas BVR 1 sp. was found to be highly resistant to cadmium with a minimal inhibitory concentration of 250 mg L-1. Cadmium was quantitatively adsorbed above pH 8 in accordance with the pseudo second order kinetics and Langmuir isotherm model with an adsorption capacity of 12.023 mg g(-1). The obtained results indicated that Halomonas BVR 1 species is very effective in adsorbing cadmium thereby opening its doors to the clean-up process of heavy metals from electronic industry effluent. (C) 2013 Elsevier B.V. All rights reserved.