Removal of 3—(3,4—dichlorophenyl)—1, 1 dimethylurea from aqueous solution by natural and activated bentonite

Abstract

AbstractThe adsorption of 3‐(3,4‐dichlorophenyl)‐1,1 dimethylurea (diuron) on bentonite desiccated at 110°C untreated, and acid treated with H2SO4 solutions over a concentration range between 0.25 M and 5.00 M, from aqueous solution at 30°C has been studied. In addition, adsorption of diuron on combined acid/heat treated samples (0.50 M and 2.50 M H2SO4/200°C and 400°C) has also been studied.The experimental data points have been fitted to the Freundlich equation in order to calculate the adsorption capacities (K) of the samples; K values range from 0.92 μg g−1 for the untreated bentonite up to 974.42 μg g−1 for the 0.50 M H2SO4/400°C acid/heat treated bentonite. The removal efficiency (R) has also been calculated; R values ranging from 2.02% for the untreated bentonite up to 97.17% for the 0.50 M H2SO4/400°C acid/heat treated bentonite. The adsorption experiments show that bentonite heat treatment is more effective than bentonite acid treatment in relation to adsorption of diuron.