RESUMO
The presence of heavy metals in the environment due to industrial activities is of serious concern because of their toxic behaviour towards humans and other forms of life. Biosorption of Pb(II) using dry bacterial biomass of Bacillus badius AK, previously isolated from water hyacinth compost, has been undertaken in batch system. The optimum conditions of biosorption were determined by investigating the initial pH, contact time, initial biomass dosage at constant temperature of 40 °C, initial metal concentration of 100 mg/L and rotational speed of 150 rpm. The optimum pH was found to be 5 and equilibrium contact time was 2.5 h. The maximum biosorption capacity of Pb(II) on Bacillus badius AK was 138.8 mg/g at an initial concentration of 100 mg/L. A kinetics study revealed that the adsorption process followed pseudo second order rate kinetics. The experimental data were fitted to the Langmuir isotherm. Characterization of the biomass indicated the presence of several functional groups. The results indicated that the bacterium Bacillus badius AK is efficient for the removal of Pb(II).
