Study of adsorption of imidacloprid onto two different textures of soils

The main goal of this research is to evaluate the potential for imidacloprid to contaminate water and ground water. For this purpose, the adsorption of imidacloprid on two different soils is investigated. Physicochemical properties such as texture, organic matter, pH of the two soils are investigated. Both soils have high organic matter and the same pH but different textures. The kinetic study of adsorption on these soils over 90 days yielded a mean half-life of 60 days. Furthermore, adsorption kinetics of imidacloprid was studied and the rate of sorption was found to conform to pseudo-second-order kinetics with 3.10 mg/g/h and 10.204 mg/g/h for soils of banana field and cocoa field respectively. Equilibrium isotherm data were analyzed according to Langmuir, Freundlich and Redlich–Peterson equations. The Redlich–Peterson isotherm gave the best correlation for the adsorption of imidacloprid adsorption on soils. The maximum adsorption capacities were determined to be 4.139 mg/g and 5.74 mg/g of soils from banana field and cocoa field respectively.The differences in adsorption capacities may be due to the effect of soils textures.Keywords: Imidacloprid, soils textures, adsorption, Redlich-Peterson model, Freundlich model, HPLC