Comparative Study on Adsorptive Characteristics of Diazinon and Chlorpyrifos from Water by Thermosensitive Nanosphere Polymer

Abstract

Diazinon and chlorpyrifos are two common organophosphorus poisons to fight the pests in Iran. The removal of these poisons from water by thermosensitive nanosphere polymer (TNP), synthesized from the copolymerization of N-isopropylacrylamide and 3-allyloxy-1,2-propanediol, was investigated. The effect of pH, contact time, and the initial concentration on the removal amount was studied. The highest removal amount of these poisons by TNP occurred at pH 7. The contact time increase improves the removal amount and the equilibrium contact time for diazinon and chlorpyrifos was 10 and 18 min, respectively. For low concentration of less than 50 mgL−1 it was shown that removal capacity remains above 95%. The initial concentration above 50 mgL−1 decreased the removal amount, in which chlorpyrifos showed a greater decrease. The kinetic data has been checked using pseudo first-order, pseudo second-order, and intraparticle diffusion equations. The intraparticle diffusion model had the best conformability for the adsorption process.