Grafting of RN-Bearing Organosilane on Kaolinite, Montmorillonite, and Zeolite for Simultaneous Adsorption of Ammonium and Nitrate.

Modification of aluminosilicate minerals using a RN-bearing organic modifier, through the formation of covalent bonds, is an applicable way to eliminate the modifier release and to maintain the ability to remove cationic pollutants. In this study, trimethyl [3-(trimethoxysilyl) propyl] ammonium chloride (TM) and/or dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (DMO) were used to graft three aluminosilicate minerals, including calcined kaolinite (Kaol), montmorillonite (Mt), and zeolite (Zeol), and the obtained composites were deployed to assess their performance in regard to ammonium (NH) and nitrate (NO) adsorption. Grafting of TM and/or DMO had little influence on the crystal structures of Kaol and Zeol, but it increased the interlayer distance of Mt due to the intercalation.