Comparison of Biosorption of Cadmium (II) from Aqueous

Heavy metal contamination of various water resources is of great concern because of the toxic effect on human being, other animals and plants in the environment. Concern over this problem has led to the development of alternative technologies for effecting the removal of these pollutants from aqueous effluents. Biosorption of cadmium (II) ions from aqueous solutions has been studied in a batch system by using a Bacillus sp. AEJ-89 (gram-positive) and Pseudomonas aeruginosa (gram-negative). Langmuir equation was based on the maximum rate of uptake of Cd (II) in Bacillus and Pseudomonas. The effects of various physicochemical factors on Cd (II) biosorption such as initial metal concentration, pH, and contact time were studied. This study has shown Cd (II) biosorption, equilibrium time of about 5 minutes for Pseudomonas and Bacillus about 10 minutes, respectively and the adsorption equilibrium data were well described by Langmuir equation. The maximum capacity has been extrapolated to 0/45, 0/85 mmol/g for Bacillus and Pseudomonas respectively. The gram positive bacterium showed more cadmium biosorption compared to the Gram-negative bacterium.