Adsorption of Pb~(2+) onto CTMAB-Montmorillonite-Pseudomonas putida Complex

Physico-chemical properties of Pb2+ adsorption onto CTMAB-montmorillonite-P.putida complex were investigated,as a function of time,Pb2+ concentration,pH and temperature.Mechanisms of adsorption were analyzed by Fourier Transform Infrared Spectroscopy(FTIR).Results indicated that adsorption of Pb2+ on surface of CTMAB-montmorillonite(CM),P.putida(P)or their complex(CMP)was a first fast and later slow process,and reached equilibrium within 90min.Sorption kinetics of Pb2+ onto P.putida could be described by Elovich equation very well,followed by first-order kinetics equation.The optimum model was the first-order kinetics equation for Pb2+ absorbed onto CM or CMP.Equilibrium adsorption of Pb2+ on the three surfaces could be fitted by Langmuir model quite well.The amount of Pb2+ adsorption increased with increasing of pH and temperature.Large difference existed between the percentage of Pb2+ desorbed with EDTA from bacteria-mineral complex and non-bacterial system.However,little discrepancies were observed for desorption of Pb2+ in corresponding system by NH4Cl and deionized water.Adhesion of Pb2+ onto surface of bacteria-mineral complex could be caused by complexing action,electrostatic force and ion exchange.