Author(s)

Min Ma, Yifeng Lu, Rongzhi Chen, Lan Ma, Ying Wang

College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China.
School of Life Sciences, Yunnan University, Kunming China.
Yunnan Academies of Science and Technology Development, Kunming, China.

This study investigated the heat-acid activated red mud used for hexavalent chromium (Cr^6＋) removal from aqueous solution. The results showed that the heat-acid activated red mud enhanced hexavalent chromium removal capacity from 0.003 to 0.015 mg·g^﹣1. Adsorption experiments were conducted as a function of adsorbent dosage, contact time, pH and reaction temperature. The removal efficiency was found to increase gradually when solution pH decreased and maximum removal was achieved at pH 2. The physico-chemical characteristics of heat-acid activated red mud were studied by using instrumental technique like Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence spectrometry (XRF). The experimental data fitted well to Langmuir isotherm model. Thermodynamic parameters indicated the adsorption process was exothermic reaction. The cost-effective performance and, simple operation suggest the heat-acid activated red mud can be taken as a promising sorbents for removal of Cr^6＋ from wastewater.

Red Mud, Heat-Acid Treatment, Adsorption Isotherm, Hexavalent Chromium Removal

Ma, M. , Lu, Y. , Chen, R. , Ma, L. and Wang, Y. (2014) Hexavalent Chromium Removal from Water Using Heat-Acid Activated Red Mud. Open Journal of Applied Sciences, 4, 275-284. doi: 10.4236/ojapps.2014.45027.