School of Earth Sciences, Damghan University, Damghan, Iran
This paper concerns the removal of Zn2+ and Cr6+ ions from waste water using a naturally occurring zeolite from semnan region in Iran. A continuous fixed-column study was carried out by using zeolite as a low-cost adsorbent for the removal of Zn2+ and Cr6+ ions from aqueous solution under the effect of various process parameters such as, grain size and time. The efficiency of removal is higher for Zn than Cr ions. The Zn2+ and Cr6+ ions uptake by zeolite increased with initial ions concentration and column height, but decreased as the flow rate increased. The adsorption capacity reached a maximum at grain size of 0.71mm.