Adsorption of oxamyl on montmorillonites

Abstract

The adsorption of oxamyl under variable conditions of time, pH and exchangeable cations on montmorillonites has been examined. Kinetic studies showed the reaction to be first order, which indicates diffusion-controlled adsorption. All the evidence obtained by studies of the effect of pH, adsorption isotherms, considerations of the chemical structure of the molecule, and X-ray diffraction and infrared spectroscopy points to a reaction mechanism for oxamyl association with acid- and base-saturated montmorillonites which involves either protonation or coordination of the exchangeable clay cations to the carbonyl of the amide group.