Biosorption characteristics of Bacillus cereus B-11 biomass for removal of Ni(II) ions from aqueous solution

The Ni(II) biosorption characteristics of Bacillus cereus B-11 biomass was examined as a function of initial pH, contact time and initial metal ion concentration. The pseudo-second-order kinetic model was found to be well suited for the entire adsorption process of Ni(II) on B-11. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the nickel ions by B-11 biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm, the maximum binding capacity of Ni(II) according to Langmuir isotherm were 88.14 mg/g at pH 6.5, shaker speed 150 rpm, at 27 °C and for 60 min. FTIR spectra showed that the principal functional sites taking part in the sorption process included carboxyl and hydroxyl groups, the mechanism analysis showed that the chemical chelating was the main adsorption form, electrostatic attraction hydrogen bonding and van der Waals forced all function in the process of adsorption. The present study indicated that B-11 biomass may be used as an inexpensive, effective and easily cultivable biosorbent for the removal of Ni(II) ions from environmental and industrial wastewater.