Removal of Pb(II) from aqueous solution on chitosan/TiO₂ hybrid film

This paper presents the adsorption of Pb(II) from aqueous solution using chitosan/TiO₂ hybrid film (CTF) adsorbent. Batch experiments were carried out as a function of solution pH, adsorption time, Pb(II) concentration and temperature. The equilibrium data fitted well with the linear Freundlich model. The adsorption process was proved to be the second grade reaction and the theoretically maximum adsorption amount at equilibrium was 36.8 mg-Pb/g. The influence parameters were optimized by response surface method (RSM), such as initial metal concentration, pH and temperature. The extreme points were gained by the Statistical Analysis System software: initial metal concentration is 50-55 mg/l, pH is 3-4 and temperature is 60 °C. Very high regression coefficient (R² = 0.9689) indicates excellent evaluation of experimental data by second-order polynomial regression model. Under this condition the theoretical adsorption efficiency is 90.6%. It illuminates that this model is reliable to optimize the adsorption process and CTF is suitable for adsorbing Pb(II) from aqueous solution.