BIOSORPTION AND SEPARATION/PRECONCENTRATION OF LEAD AND NICKEL ON RHODOCOCCUS RUBER BIOMASS

Abstract

At the present time emphasis is given to the utilization of microorganisms because of their great ability to absorb metal ions from aqueous solution. Hence, in this study, Pb2+ and Ni2+ ions at trace levels were separated and preconcentrated on a column containing a bacterium, Rhodococcus ruber bacterial biomass (RrBB), as a new solid phase extraction technique prior to their flame atomic absorption spectrometry (FAAS) determination. The optimum experimental and analytical parameters such as pH of sample solution, volume and concentration of eluent, flow rate of sample solution and eluent, sample volume, effect of common matrix ions and capacity of biosorbent were investigated and optimized. Under the optimized conditions, the preconcentration factors for Pb2+ and Ni2+ were calculated as 150 and 100, respectively. The analytical detection limits for Pb2+ and Ni2+ were 0.32 mu g L-1 and 0.24 mu g L-1 respectively. The Langmuir monolayer adsorption capacity of biomass was estimated as 42.91 and 6.78 mg g(-1) for Pb2+ and Ni2+, respectively. Certified reference material (NIST SRM 1640a) was also used to confirm the accuracy of the method. The developed solid phase extraction method was applied successfully for the determination of Pb2+ and Ni2+ in various water samples.