Some aspects of the glyphosate adsorption on montmorillonite and its calcined form

Influences of pH and ionic strength on the aggregation of montmorillonite particles in the presence or absence of glyphosate (PMG) were studied. Adsorption isotherms and X-ray diffraction indicated that ligand exchange is the main mechanism of PMG adsorption. The surface coverage increased with the ionic strength and was more noticeable at high PMG concentration indicating inner-sphere surface complexation. At low PMG concentration the inner-sphere surface complexes are located of the external clay mineral surface while at high PMG concentration the surface complexes are also formed in the interlayer space.