Microbial biosorption of copper and lead from aqueous systems.

Biosorption of metal ions from aqueous systems was evaluated using a culture of acidic soil isolates grown in a completely mixed, aerobic, semi-batch culture reactor. The laboratory scale system was used to test single and bimetallic solutions of copper and lead with sulfates, chlorides, or nitrates. To elucidate the key factors influencing biosorption and to characterize metal uptake by cellular and extra cellular components of the microbial system, a dialysis testing procedure was developed. A direct contact technique was used to determine the rate of metal sorption on cellular surfaces. The effectiveness of biosorption was influenced by pH, initial metal concentrations, and anionic composition. Respirometric tests were carried out to identify potential inhibitory effects of metal accumulation on microbial oxygen uptake rates.