Adsorption of Nitenpyram and p-Cresol from Water in Binary Components System with Modified Resin with Tannic Acid

Abstract

The adsorption behaviour of nitenpryram and p-cresol in water onto the resin modified with tannic acid based was investigated by static adsorption experiments at different temperature (288, 303, 318 K) in single component and binary components system. The adsorption capacities and adsorption selectivity for nitenpryram and p-cresol in water were tested. The results show that the adsorption is fitted better by Freundlich model than Langmuir model. The adsorption of nitenpryram on the resin modified with tannic acid was an endothermic process by the positive adsorption enthalpy and an exothermic process of p-cresol with the negative adsorption enthalpy. The resin had better absorbability for nitenpryram than for p-cresol and the adsorption selectivity of nitenpryram was larger than one. Gibbs free energy, enthalpy change and entropy change had changed in binary components system, to demonstrate the existence of the cooperative effect. A high removal rate of 48.55-94.26 % was obtained for nitenpryram and 28.93-71.71 % for p-cresol in single component system, which was lower in binary components system. But in binary components system of the same initial concentration of nitenpryram and p-cresol, when the equilibrium concentration was higher, the cooperative adsorption existed, which may be due to the hydrogen bonding or weak acid-base interaction between nitenpryram and p-cresol. The competitive adsorption existed, because the adsorption of nitenpryram onto the resin had just smaller change in the presence of p-cresol, but the adsorption of p-cresol was weakened in the presence of nitenpryram.