抄録
The adsorption behaviour and reaction mechanism of oxamyl with acid and base saturated montmorillonites were investigated with the help of adsorption isotherms, Freundlich constants, thermodynamic parameters, IR and X-ray spectroscopy. Adsorption data were analysed, applying the linear form of the Freundlich equation. A qualitative assessment of the nature of the reaction was made with the help of these measures. Effect of temperature and different cations was also studied. The values of the equilibrium constant and standard free energy change pointed to the higher affinity of oxamyl for montmorillonite surface, and that the adsorption was in the order Na->H->Ca-montmorillonite. The exothermic nature of interaction indicates that the adsorption phenomenon of oxamyl on the montmorillonite surface occurred through a bonding mechanism. The data indicate the existence of protonation and/or coordination between the exchangeable cation of the montmorillonite and oxygen of the amide group of oxamyl molecule.
