Preparation of Micro-porous Chitosan Membrane and Its Adsorption Property for Cr(VI) Ions

Chitosan (CS) micro-porous membranes were prepared by blending-phase inversion method using chitosan as film-forming polymer, polyethylene glycol (PEG) as porogen and glycerol as plasticizer. Adsorption experiments were conducted under varied Cr(VI) ions concentration, pH values, contact time and temperature. The results indicated that when the ratio of chitosan to polyethylene glycol and glycerol was 1:0.5:0.5 at pH of 2.79, the prepared CS membrane exhibited the highest adsorption capacity of 168.41 mg g(-1) under Cr(VI) ions concentration of 100 mg L-1, contact time of 4 h, and membrane dosage of 10.0 mg. Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms at different Cr(VI) ions concentrations. The equilibrium data was found to be fitted well to the Langmuir isotherm. Pseudo-first-order and pseudo-second-order kinetics models were used to describe the membrane adsorption.