Biosorption of Cu(II) on extracellular polymers from Bacillus sp. F19.

Biosorption can be an effective process for the removal of heavy metals from aqueous solutions. The adsorption of Cu(II) from aqueous solution on the extracellular polymers (EPS) from Bacillus sp. (named MBFF19) with respect to pH, incubation time, concentration of initial Cu(II), and biosorbent dose was studied. Biosorption of Cu(II) is highly pH dependent. The maximum uptake of Cu(II) (89.62 mg/g) was obtained at pH 4.8. Biosorption equilibrium was established in approximately 10 min. The correlation coefficient of more than 0.90 turned out that the adsorption process of Cu(II) on MBFF19 was in accordance with both Langmuir and Freundlich isotherms. The pseudo- first and second order models were applied to examine the kinetics of the adsorption, whereas the latter was found to be in harmony with the kinetic data better. Because of the outstanding uptake capacity of Cu(II), MBFF19 produced by Bacillus sp. was proved to be an excellent biosorbent for removing Cu(II) from aqueous solutions.