Adsorption and Deactivation of Atrazine and Diuron by Charcoals

Abstract

The adsorption of 2-chloro-4-(ethylamino)-6-(isopropylamino)- s -triazine (atrazine) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) from aqueous solution by charcoal varied widely with the type of charcoal tested. However, adsorption in solution was directly related to the deactivating properties of the charcoals for the two herbicides in soil. Several charcoals deactivated residues of 0.3 ppmw of atrazine and 1.0 ppmw of diuron when they were present at concentrations of 30 to 50 ppmw in the soil. Activation of the charcoal was essential for the adsorption and deactivating properties. A simple laboratory test was developed for assessing activated charcoals for use in deactivation studies in soil.