Study on Adsorption Kinetic Characteristics of Propineb Pesticide on Activated Carbon

Abstract: The adsorption characteristics of propineb pesticide onto activated carbon has been investigated for the adsorption in aqueous solution with respect to initial concentration, contact time and temperature in batch experiment. The Langmuir and Freundlich adsorption models were applied to described the equilibrium isotherms and isotherm constants were also determined. The Freundlich model agrees with experimental data well. slope of isotherm line indicate that activated carbon could be employed as effective treatment for removal of propineb. The pseudo first order, pseudo second order kinetic models were use to describe the kinetic data and rate constants were evaluated. The adsorption process followed a pseudo second order model, and the adsor-ption rate constant(k2) decreased with increasing initial concentration of propineb. The activation energy, change of free energy, enthalpy, and entropy were also calculated to predict the nature adsorption. The estimated values for change of free energy were-7.28,-8.27 and-11.66 kJ/mol over activated carbon at 298, 308 and 318 K, respectively. The results indicated toward a spontaneou