The surfactant Brij 35 could enter the interlayer of montmorillonite by replacing the water coordinated to cations. The amount of surfactant entering the interlayer of montmorillonite increased with increasing surfactant concentration. As Brij 35 entered the interlayer, the hydrophobicity of clay interlayer was enhanced. Increasing the clay interlayer hydrophobicity allowed atrazine to enter the clay interlayer as well. This transformation represents chemical degradation, since atrazine is relatively resistant to microbial degradation.
Atrazine hydrolysis occurs under acid, neutral, or basic conditions.
Hydrolysis is slow under neutral conditions, but it increases with either increasing alkalinity or acidity. It is clearly shown that the presence of Brij 35 significantly increased the rate of atrazine hydroxylation in Ca-montmorillonite. Atrazine hydroxylation enhancement resulted from the interaction of Brij 35 with atrazine followed by the interaction of atrazine with the clay surface. In essence, Brij 35 increased the apparent level of alkalinity on the clay surfaces. Atrazine mobility in soil clays was evaluated using breakthrough studies.