Biosorption of Copper (II) on Bioflocculant PS-2 from Aqueous Solution: Equilibrium and Kinetic Studies

To assess the potential applicability of bioflocculant PS-2, a bacterial extracellular polysaccharide, to wastewater treatment as a biosorbent, the biosorption of PS-2 to remove the Cu (II) ions was investigated by using batch biosorption procedure. The effects such as pH, initial metal ions concentration, biosorbent dosage on the adsorption capacities of PS-2 were studied. The optimum uptake of Cu (II) ions was observed at pH 5 with a value of 76.9 mg/g, the kinetics of biosorption of Cu (II) was fast, reaching at equilibrium in 90 min. Biosorption equilibrium datas were best described by Langmuir isotherm model followed by Freundlich models. The biosorption kinetics followed the pseudo-second order and intraparticle diffusion equations. The FTIR analysis showed that OH, C-H, C=O and COOH groups were involved in the biosorption of Cu (II) ions on PS-2, and carboxyl and hydroxyl functional groups were mainly responsible for the biosorption of Cu (II). The bioflocculant PS-2 was capable of removing Cu (II) ions from wastewater.