Behavior of the herbicide dimepiperate with homoionic clays in aqueous solution

The adsorption of the herbicide dimepiperate with homoionic Fe3+) ,Al3+,Cu2+ ,Ca2+ ,K+ and Na+ saturated montmorillonite in aqueous solution was investigated. The adsorption to six homoionic clays was described well by the Freundlicb equation. The adsorption capacity decreases in order to Cu2+ >Fe3+ >Al3+) >Ca2+ >K+ >Na+ clay and the same order of their acidities except for Cu2+,because Cu2+ has great catalytical ability. The kinetic of its hydrolysis was also studied. Among the six metal ions,Cu2+ clay exhibited a particular affect of catalysis. The IR results suggest that only findirig the adsorption of the hydrolytic product on Cu2+clay and dimepiperate on K+,Na+ clays, there being two compounds (dimepiperate and its hyrolytic product) adsorptions on Fe3+ and Al3+) clays.