Removal of chromate from aqueous solution using treated natural zeolite

This paper present the possible alternative removal options for the development of safe drinking water supply in the chromium-affected areas. The Cr (VI) state is of particular concern because of its toxicity. The mordenite has suitable mineralogical properties that enable them to be used for ion-exchange processes. This includes total cation exchange capacity. However, in the present work, the modified-natural zeolite was used as an adsorbent for the removal of Cr (VI) from aqueous solution. The ability of modified natural zeolite (mordenite) to remove inorganic anion was investigated. Laboratory experiments were conducted examining the effect of the sorption of cationic surfactants. On the basis of the results of this study, the HDTMA-HSO₄ modified zeolite appears suitable as a sorbent for hexavalent chromium whereas EHDDMA-modified zeolite were not removed with the same efficiency. The sorption of chromate on HDTMA-zeolite results from a combination of entropic, coulombic, hydrophobic effects, and HDTMA counterion.