Experimental modeling of the adsorption kinetics of Cd (II) and Pb (II) ions by Calix [4] arene surface

The removal of Cd2+ and Pb2+ ions from wastewater using p-tert-butyl-calix[4] arene was investigated in terms of initial pH, initial concentration, adsorbent dosage, contact time and temperature. The maximum adsorption occurred at the pH value of 6. The adsorbent studied exhibits high efficiency for Cd (II)and Pb (II) adsorption and the equilibrium states could be achieved in 10 min. Adsorption kinetics data were modeled using the first order, the pseudo-first and pseudo-second order, Elvoich equations and intra-particle diffusion models. The results show that pseudo-second order kinetic model was found to correlate the experimental data as well.