Kaolinite Oxamyl Interactions

Chemical Laboratories, D. S. College, Aligarh-202 001 Manuscript received 16 May 1979, accepted 25 August 1980 The adsorptive behaviour of oxamyl with H-, Na- and Ca- kaolinites was studied. The effect of time on adsorption showed that process was diffusion controlled. Kinetic studies showed that reaction was of first order. Maximum adsorption occurred at pH 6.5. The adsorption isotherms and desorption experiments provided evidence for a partly chemisorption and partly physical adsorption of oxamyl on clay surface. Inferences on the protonation of the carbonyl oxygen of the oxamyl molecule by H+ ions on kaolinite and/or the coordination of the metallic cations of kaolinite to the carbonyl of amide group found support from adsorption isotherms, thermodynamic parameters, X-ray and IR studies