Adsorption of atrazine herbicide from water by Diospyros kaki fruit waste activated carbon

Abstract In this work, Diospyros kaki fruit waste was employed as a precursor material to develop a high surface area activated carbon, which efficiently removed the toxic herbicide atrazine (ATZ) from synthetic water solutions and river waters. The alternative activated carbon presented excellent characteristics and structure, including high values of specific surface area (1067 m2 g-1) and pore volume (0.530 cm3 g-1) and some important functional groups on the surface. The temperature positively influenced the adsorption capacity, from 194.20 to 211.51 mg g- 1. The Freundlich model was the proper one to represent the equilibrium data. Thermodynamic parameters confirmed the endothermic nature of the adsorption process. Kinetic studies confirmed that equilibrium was reached until 240 min, regardless of ATZ initial concentration. The LDF model adjusted well to the kinetic data, resulting in a diffusion coefficient ranging from 0.89x10-9 to 1.63x10-9 cm2 s-1 as the ATZ concentration increased. The activated carbon also decreased 85% of the ATZ concentration in a river water sample. Overall, the activated carbon developed from Diospyros kaki fruit waste presented an efficient ATZ removal from aqueous matrices.