Fundamental aspects of copper and zinc removal from aqueous solutions using a Streptomyces lunalinharesii strain

The first line of biosorption technology research aims to enhance pathways for the use of novel biosorbents, and thus, reduce the utilization of noneco-friendly process based in chemical products, and to provide economic and sustainable alternatives to conventional process. This subject presents a multidisciplinary approach and requires the fundamentals of water chemistry, biochemistry and surface chemistry to name a few. Biological processes have been attracting attention in heavy metals removal by bacterial strains, due to lower operating costs and their potential applications for ionic metal species removal from aqueous solutions even in high concentrations. The ability of Streptomyces lunalinharesii to sorb copper and zinc from aqueous solutions was investigated through batch experiments at 25 degrees C. Various sorption parameters such as contact time, initial metal concentration, pH and biomass concentration and the sorption capacity were studied. The degree of copper and zinc removal achieved values around 81% and 60% at pH 5.0 and 6.0, respectively. Moreover, the metals uptake remained constant for contact time above 30 min. The experimental data at equilibrium were fitted to Langmuir and Freundlich adsorption isotherm models and the model parameters were evaluated. The kinetic study showed that the pseudo-second-order rate equation better described the biosorption process. The FTIR analysis revealed that hydroxyl, carboxyl and amine groups were major binding groups. (c) 2012 Elsevier Ltd. All rights reserved.