Interaction of Chlordimeform with Clay Minerals

Maria C. Hermosin and J. L. Perez Rodriguez
Centro de Edafologia y Biologia Aplicada del Cuarto del C.S.I.C., Apartado 1052, Sevilla, Spain

Abstract: The adsorption-desorption of the cationic pesticide chlordimeform from aqueous solutions on montmorillonite, kaolinite, illite, and vermiculite appears to be a cation-exchange process coupled with the coadsorption of neutral molecules and the extraction of Al from the structure of the mineral. Chlordimeform adsorption on montmorillonite, illite, and vermiculite by cation exchange is an irreversible process, whereas chlordimeform adsorbed on kaolinite is weakly bonded to the clay and easily removed by washing with water. X-ray powder diffraction and infrared spectroscopic data show that chlordimeform cations are adsorbed in the interlamellar spaces of montmorillonite at charge sites, lying in a flat position in contrast to kaolinite, illite, and vermiculite, where they adsorb on external surfaces or charge sites close to the crystal edges.

Key Words: Adsorption • Chlordimeform • Illite • Kaolinite • Montmorillonite • Pesticide • Vermiculite

Clays and Clay Minerals; April 1981 v. 29; no. 2; p. 143-152; DOI: 10.1346/CCMN.1981.0290209
© 1981, The Clay Minerals Society
Clay Minerals Society (www.clays.org)