Infiltration of hexavalent chromium (Cr(VI)) into the human body poses significant health risks, including the risk of developing cancer and increased mortality rates. The discharge of chromium-contaminated wastewater from industrial processes exacerbates environmental pollution, highlighting the necessity for efficient, cost-effective, and environmentally friendly treatment methods. In recent years, there has been a growing emphasis on the application of nanoscale zero-valent iron particles (NZVI) for mitigating Cr(VI) water pollution. In the present study, NZVI was synthesized using a liquid-phase reduction method employing sodium borohydride (NaBH), and natural montmorillonite (Mt) was incorporated as a carrier, resulting in the creation of NZVI/Mt., a composite material. Characterization of this composite was performed using scanning electron microscopy (SEM), Transmission Electron Microscope (TEM), Specific surface area and pore size (BET), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) techniques. The investigation encompassed an exploration of the influence of initial pollutant pH levels, adsorbent dosages, and initial pollutant concentrations on the adsorption process. The research findings indicate that, at an initial pH of 4.0, NZVI/Mt. achieves a removal efficiency of 92.41% for a Cr(VI) solution with an initial concentration of 40 mg/L. The NZVI/Mt. composite adheres to both a pseudo-second-order kinetic model and the Langmuir isotherm model, showcasing a significant maximum adsorption capacity of 67.75 mg/g for Cr(VI). Furthermore, thermodynamic analysis revealed an exothermic nature of the adsorption process. This experimental approach effectively resolved issues related to NZVI particle agglomeration, offering a simplified, cost-effective, and environmentally friendly preparation method. Consequently, the NZVI/Mt. composite material demonstrates effective treatment of Cr(VI) mildly contaminated wastewater.

中文翻译：

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用于去除水溶液中 Cr(VI) 的纳米零价铁/蒙脱石复合材料：表征、性能和机理见解

六价铬 (Cr(VI)) 渗入人体会带来严重的健康风险，包括患癌症和死亡率增加的风险。工业过程中铬污染废水的排放加剧了环境污染，凸显了高效、经济、环保的处理方法的必要性。近年来，人们越来越重视纳米级零价铁颗粒（NZVI）在减轻六价铬水污染方面的应用。在本研究中，采用硼氢化钠（NaBH）液相还原法合成了NZVI，并掺入天然蒙脱石（Mt）作为载体，从而创建了NZVI/Mt.复合材料。使用扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、比表面积和孔径 (BET)、X 射线衍射 (XRD) 和傅里叶变换红外 (FT-IR) 技术对该复合材料进行表征。该研究包括探索初始污染物 pH 值、吸附剂剂量和初始污染物浓度对吸附过程的影响。研究结果表明，在初始 pH 值为 4.0 时，NZVI/Mt.对于初始浓度为 40 mg/L 的 Cr(VI) 溶液，去除效率达到 92.41%。 NZVI/山。复合材料遵循准二级动力学模型和 Langmuir 等温线模型，对 Cr(VI) 表现出 67.75 mg/g 的显着最大吸附容量。此外，热力学分析揭示了吸附过程的放热性质。该实验方法有效解决了NZVI颗粒团聚的相关问题，提供了一种简化、经济高效且环境友好的制备方法。因此，NZVI/Mt。复合材料证明可以有效处理 Cr(VI) 轻度污染的废水。