Department of Chemistry, National Institute of Technology, Rourkela 769008, Orissa, India.
J Hazard Mater. 2010 Jul 15;179(1-3):1007-13. doi: 10.1016/j.jhazmat.2010.03.105. Epub 2010 Mar 31.
A laboratory study was conducted to investigate the ability of activated CO(2)-neutralized red mud (ANRM) for the removal of arsenate from the aqueous solutions. The batch adsorption experiments were conducted with respect to adsorbent dose, equilibrium pH, contact time, initial arsenate concentration, kinetics, Langmuir isotherms. The mechanisms involved in adsorption of arsenate ions on ANRM were characterized by using XRD, FT-IR, UV-vis, SEM/EDX, and chemical methods. The percentage removal was found to increase gradually with decrease of pH and maximum removal was achieved at pH approximately 4. Adsorption kinetic studies revealed that the adsorption process followed pseudo-second-order kinetics and equilibrates within 24 h. FT-IR spectra of ANRM before and after adsorption reveals the binding of arsenate to the adsorbent. The adsorption data were fitted to linearly transformed Langmuir isotherm with R(2) (correlation coefficient)>0.99. Arsenate adsorbed ANRM can be regenerated using NaOH solution at pH 12.0.
进行了一项实验室研究，以研究活性 CO(2)-中和的赤泥 (ANRM) 去除水溶液中砷酸盐的能力。进行了批处理吸附实验，涉及吸附剂剂量、平衡 pH 值、接触时间、初始砷酸盐浓度、动力学、朗缪尔等温线。通过 XRD、FT-IR、UV-vis、SEM/EDX 和化学方法对吸附砷酸盐离子的吸附机理进行了表征。去除率随着 pH 值的降低而逐渐增加，在 pH 值约为 4 时达到最大值。吸附动力学研究表明，吸附过程遵循准二级动力学，在 24 小时内达到平衡。吸附前后 ANRM 的 FT-IR 光谱表明砷酸盐与吸附剂结合。吸附数据符合线性转化的朗缪尔等温线，R(2)(相关系数)>0.99。在 pH 12.0 下使用 NaOH 溶液可以再生吸附砷酸盐的 ANRM。
