Adsorption of inorganic anionic contaminants on surfactant modified minerals

Abstract

Organo-mineral complexes were obtained by treatment of aluminosilicate minerals (zeolite, bentonite and diatomaceous earth) with a primary amine (oleylamine) and an alkyl ammonium salt (stearyldimethylbenzyl ammonium chloride). The modification of the zeolite surface was carried out in two steps. The first step was treatment of the zeolite with 2M HCl. This acid treatment of the zeolite increased its affinity for neutral molecules such as surface-active amines. The second step of the modification was the adsorption of oleylamine on the acid treated zeolite. Four types of organo-mineral complexes were prepared and their anion adsorption properties were compared to those of organo-zeolite. The adsorption of sulphate bichromate and dihydrogenphosphate anions on the organo-mineral complexes was investigated. The anion adsorption measurements showed that the most efficient adsorbent for anion water pollutants was the primary amine modified H+-form zeolite.

Keywords

• zeolite
• bentonite
• diatomaceous earth
• oleylamine
• adsorption
• anions.