Adsorption of acetanilide herbicides on soil and its components II. Adsorption and catalytic hydrolysis of diethatyl-ethyl on saturated Na+-, K+-, Ca2+-, and Mg2+-montmorillonite

作者：Liu WP^*; Fang Z; Liu HJ; Fang WC

来源：Journal of Environmental Sciences, 2001, 13(2): 137-142.

• adsorption
• catalytic hydrolysis
• diethatyl
• diethatyl-ethyl
• montmorillonite

Adsorption and catalytic hydrolysis of the herbicide diethatyl-ethyl [N-chloroacetyl-N-(2, 6-diethylphenyl) glycine ethyl ester] on homoionic Na+-, K+-, Ca2+-, and Mg2+-montmorillonite clays were investigated in water solution. The Freundlich adsorption coefficient, K-f, got from isotherms on clay followed the order of Na+ approximate to K+ > Mg2+ approximate to Ca2+. Analysis of FT-IR spectra of diethatyl-ethyl adsorbed on clay suggests probable bonding at the carboxyl and amide carbonyl groups of the herbicide, The rate of herbicide hydrolysis in homoionic clay suspensions followed the same order as that for adsorption, indicating that adsorption may have preceded and thus caused hydrolysis. Preliminary product identification showed that hydrolysis occurred via nucleophilic substitution at the carboxyl carbon, causing the cleavage of the ester bond and formation of diethatyl and its dechlorinated derivative, and at the amide carbon, yielding an ethyl ester derivative and its acid. These;pathways also suggest that hydrolysis of diethatyl-ethyl was catalyzed by adsorption-on the clay surface.

• 出版日期2001-4
• 单位浙江大学