Environmental Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
Department of Environmental Health Engineering, Faculty of Health, Kurdistan University of Medical Sciences, Sanandaj, Iran.
Sci Rep. 2022 Jul 6;12(1):11473. doi: 10.1038/s41598-022-15844-w.
The adsorption of cadmium ions by magnetite (FeO)@biosilica/alginate (MBA nano-hybrid) was the main aim of the present investigation. Herein, MBA nano-hybrid was synthesized via chemical precipitation technique. As-synthesized MBA nano-hybrid was characterized using FT-IR, FESEM and XRD analyzes. Based on the results, the maximum adsorption capacity of the adsorbent for the removal of Cd(II) was obtained at the initial pH of 7.0. At the initial Cd(II) concentration of 40 mg/L, increasing the reaction time to 180 min led to the Cd adsorption of 35.36 mg/g. Since the removal of Cd(II) after the reaction time of 60 min was insignificant, the reaction time of 60 min was considered as optimum reaction time for performing the experimental runs. According to the results, Langmuir isotherm and pseudo-second order kinetic models were the best fitted models with high correlation coefficients (R > 0.99). The results of thermodynamic study indicated exothermic (positive ΔH°) and spontaneous nature (negative ΔG°) of the adsorption of Cd(II) on the surface of MBA nano-hybrid. Negligible reduction in the adsorption capacity of the nano-hybrid was observed (16.57%) after fifth experimental runs, indicating high reusability potential of the as-synthesized nano-hybrid adsorbent.
本研究的主要目的是研究磁铁矿（FeO）@生物硅/海藻酸钠（MBA 纳米杂化体）对镉离子的吸附作用。本文采用化学沉淀法合成了 MBA 纳米杂化体。采用 FT-IR、FESEM 和 XRD 分析对合成的 MBA 纳米杂化体进行了表征。结果表明，吸附剂对 Cd(II)的最大吸附容量出现在初始 pH 值为 7.0 时。在初始 Cd(II)浓度为 40mg/L 的情况下，将反应时间延长至 180min 可使 Cd 的吸附量达到 35.36mg/g。由于反应 60min 后 Cd(II)的去除率不明显，因此选择 60min 作为最佳反应时间进行实验。结果表明，Langmuir 等温线和拟二级动力学模型是最适合的模型，具有较高的相关系数（R>0.99）。热力学研究结果表明，Cd(II)在 MBA 纳米杂化体表面的吸附是放热（正 ΔH°）和自发的（负 ΔG°）。纳米杂化体经过五次实验后，其吸附容量仅略有下降（16.57%），表明所合成的纳米杂化体吸附剂具有较高的可重复使用潜力。
