Biosorption of Pb(II) and Zn(II) from aqueous solutions by living B350 biomass

Abstract

A B S T R A C TBeneficiation production wastewater is a kind of wastewater generated from exploiting minerals, where the main pollutants are heavy metals and organic agents. In this study, living B350 biomass (a mixture of various micro-organisms) was used to remove Pb(II) and Zn(II) from aqueous solutions. The effects of pH, biomass dosage and contact time on removal ratios of Pb(II) and Zn(II) were studied. Two kinetic models, pseudo-first-order and pseudo-secondorder, were used to fit the experimental results. The chemical changes of B350 biomass before and after adsorption were monitored by Energy Dispersion X-ray (EDX) spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. In addition, the feasibility of B350 to remove heavy metals and m-cresol simultaneously was investigated. The results showed that the removal ratios of heavy metals increased with increasing dosage of biosorbent. When B350 dosage was 1.0 g/L, 84.88% of Pb(II) and 38.06% of Zn(II) can be removed after 2 h of adsorption at 25˚C. The adsorption of Pb(II) and Zn(II) on B350 was coincident with Langmuir and Freundlich isotherms, respectively. Pseudo-second-order model can best describe the adsorption process. EDX and FTIR results indicated that ion exchange and complexation might exist during the adsorption of Pb(II) and Zn(II). The living B350 biomass can not only adsorb heavy metal ions, but also biodegrade organic pollutants through metabolizing itself.