Removal of Cr(VI) Using a Column Packed with Lithium Intercalated Gibbsite.

Hexavalent chromium is one of the toxic contaminants which commonly present in industrial wastewater. In order to decrease its impact on ecosystems, many techniques, including reduction, adsorption, membrane separation, and bio-remediation, have been developed. Adsorption is one of the most commonly used techniques for Cr(VI) removal due to its simplicity and efficiency. In our previous batch studies, lithium intercalated gibbsite (LIG), a layer mineral, has been found an effective adsorbent for Cr(VI) in suspension. However, separation of nano-sized LIG particle from solution is difficult, a weakness leading to a decrease in its application. Therefore, in this research, LIG was packed into an acrylic column, and the adsorption of Cr(VI) on LIG was investigated with various concentrations of Cr(VI). The results show that 73.9, 96.6 and 99.7% of Cr(VI) was removed with the addition of 600, 200 and 20 mg L^-1 of Cr(VI), respectively. That is, the adsorption decreased with increase in initial Cr(VI) concentrations. In addition, the amount of Cr(VI) adsorption on LIG were found to be indifferent with batch or column experiment when the ratios of solid weights and reactive volumes were the same.