In this work, aluminum industrial waste, red mud (RM), was activated to verify its potential in the management of electroplating wastewater containing hexavalent chromium (Cr(VI)). A comparison between the adsorption capabilities of RM and activated red mud (ARM) towards Cr(VI) from aqueous solutions was made. The effects of several parameters were evaluated. The adsorbents were characterized by field emission scanning electron microscopy (FESEM), Fourier transmission infrared spectroscopy (FTIR), x‐ray diffraction (XRD), zeta potential, and thermogravimetric analysis (TGA). The particle size was observed as 23.59 nm. The ARM demonstrated an acceptable adsorption capacity of 25.641 mg/g at a pH of 2, adsorbent dosage of 2 g/L, initial Cr(VI) concentration of 100 mg/L, at 25°C. The experimental data is in good agreement with Langmuir adsorption isotherm. The kinetic study was performed to verify that the adsorption follows pseudo‐second‐order kinetics. In addition, the ARM showed decent recyclability for adsorbing Cr(VI) as even after three adsorption cycles, and the adsorption capacity was reduced by ~30%. The results recommend ARM to be an efficient and cost‐effective adsorbent for Cr(VI) removal from industrial wastewater.

中文翻译：

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赤泥（工业铝废料）：电镀废水的环保处理

在这项工作中，铝工业废料赤泥（RM）被激活，以验证其在处理含六价铬（Cr（VI））的电镀废水中的潜力。比较了RM和活性赤泥（ARM）对水溶液中Cr（VI）的吸附能力。评估了几个参数的影响。通过场发射扫描电子显微镜（FESEM），傅立叶透射红外光谱（FTIR），X射线衍射（XRD），ζ电位和热重分析（TGA）对吸附剂进行表征。观察到粒径为23.59nm。ARM证明在pH为2时可接受的吸附容量为25.641 mg / g，在25°C下吸附剂剂量为2 g / L，初始Cr（VI）浓度为100 mg / L。实验数据与Langmuir吸附等温线吻合良好。进行了动力学研究，以验证吸附遵循伪二级动力学。此外，ARM甚至在三个吸附循环后仍显示出良好的可吸附Cr（VI）的可回收性，吸附能力降低了约30％。结果建议ARM是一种从工业废水中去除Cr（VI）的有效且具有成本效益的吸附剂。