Adsorption of chlorotriazine herbicide onto unmodified and modified kaolinite: Equilibrium, kinetic and thermodynamic studies

Abstract

In the recent time, adsorption is a commonly economical way for removal of pollutants from wastewater. Chlorotriazine has been a serious threat to life of both human and animal. Modified kaolinite clays were separately prepared by chemical impregnation method with 2 M H2SO4 and 2 M NaOH respectively in w/v of 1:2 for a period of 24 h to give unmodified kaolinite (UKC), 2 M H2SO4 modified kaolinite (2-AKC) and 2 Mm3 NaOH modified kaolinite clays (2-BKC) respectively. The UKC with maximum intake value (125.3 mg/g) was derived at equilibrium of 1100 mg/L while 96.65 mg g−1 of 2-AKC was obtained at equilibrium of 500 mg L−1 and that of 2-BKC was found at equilibrium of 700 mg/L. The Langmuir isotherm best explained the removal of Chlorotriazine onto various kaolinite clays while pseudo 2nd order kinetics fitted best. Thus, kaolinite clays have been proved as a potential adsorbent for the removal of chlorotriazine molecules. Keywords: Atrazine, Kaolinite clay, Batch process, Equilibrium, Kinetics