The Use of Hematite for Chromium(VI) Removal
The Use of Hematite for Chromium(VI) Removal
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使用赤铁矿去除六价铬
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
D. C. Rupainwar
中科院分区：
文献类型：
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作者：
D. B. Singh;G. Gupta;G. Prasad;D. C. Rupainwar
研究了不同浓度、温度和pH条件下赤铁矿对Cr（VI）的去除能力，当Cr（VI）初始浓度为19.23 μmol/L、赤铁矿初始浓度为40 g/L时，在40 °C、pH为2.7时，对Cr（VI）的去除率最高（97%）。本体系的平衡数据符合Langmuir等温式。反应动力学进行了研究，该过程涉及膜和孔扩散在不同程度上。测定了传质系数和扩散系数。热力学参数表明该过程的自发和吸热性质。随着pH值的降低，Cr（VI）的吸收增加，最大去除率归因于在表面形成带正电荷的铁水络合物，随后与主要的HCrO 4-物种相互作用。根据平衡吸附质浓度的知识，建立了预测平衡吸附量的经验方程。
Abstract The ability of hematite to remove Cr(VI) from aqueous solutions has been studied at different concentrations, temperatures and pH. The maximum removal (97%) was observed at 40 °C and pH 2.7 with initial concentrations of 19.23 μmol/L Cr(VI) and 40 g/L hematite. The equilibrium data obey the Langmuir isotherm for the present system. The reaction dynamics have been studied and the process involves both film and pore diffusion to different extents. Mass transfer and diffusion coefficients have been determined. Thermodynamic parameters indicate the spontaneous and endothermic nature of the process. The uptake of Cr(VI) increases as pH decreases and the maximum removal has been attributed to the formation of positively charged aquacomplexes of iron at the surface and a subsequent interaction with the dominant HCrO4 ‐species. An empirical equation has been developed to predict equilibrium adsorption capacity from knowledge of equilibrium adsorbate concentration.