Mode of Chemical-Degradation of s-Triazines by Montmorillonite.

Chemical hydrolysis of the s-triazines after interaction with less than 2-micron (equivalent spherical diameter) montmorillonite clay occurs as a result of protonation at the colloidal surface; protonation occurs even when the exchange sites are occupied by metallic cations. The adsorbed hydrolytic degradation product is not the hydroxy analog, but it is predominantly the keto form of the protonated hydroxy species. This cationic form is held tightly by the clay which may restrict vertical movement and entrance into groundwater. Protonation of the hydroxy analog occurs on the heterocyclic ring nitrogen.