Faculty of Engineering and IT, University of Technology Sydney, P.O. Box 123, Broadway, Ultimo, NSW 2007, Australia.
School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Gwangju, 61186, Republic of Korea.
Chemosphere. 2021 May;271:129820. doi: 10.1016/j.chemosphere.2021.129820. Epub 2021 Feb 3.
Continuous and selective recovery of copper (Cu) from heavy metal wastewater not only mitigates the pollution of environment but also can be applied for industrial field. Due to several advantages such as large pore size, easy modification, physical and chemical stabilities, mesoporous silica material, SBA-15, has been synthesized via hydrothermal reaction in this study. For enhancing the adsorption capacity and selectivity for Cu ions, prepared SBA-15 was modified with manganese loading and amine-grafting (MN-SBA) then granulated by alginic-acid (GMN-SBA), successfully. Adsorption capacities for heavy metals such as Cu, Zn, Ni and Mn were 2.11, 1.24, 1.74 and 1.25 mmol/g on MN-SBA and decreased to 1.23, 0.68, 0.86 and 0.65 when it was granulated. Even though the adsorption capacities of GMN-SBA for heavy metals decreased by 40-50%, it enabled easy regeneration and separation process when applied for continuous fixed-bed column adsorption mode. Specifically, the results demonstrated that GMN-SBA was able to be reused for 5 times while maintaining over 80% adsorption capacities. Fixed-bed adsorption results were well explained by dynamic adsorption model incorporated with linear driving force approximation (LDFA) model. The simulation of fixed-bed adsorption tests was proceeded in terms of bed length, feeding concentration and flow rate, and it showed the breakthrough times were shifted in the axis of time. In multi-component adsorption, LDFA model showed a high overshoot phenomenon of the breakthrough curves for Zn, Ni and Mn compared to Cu. This reflected the high affinity of Cu towards GMN-SBA compared to other heavy metals.
从重金属废水中连续、选择性地回收铜（Cu）不仅可以减轻环境污染，还可以应用于工业领域。由于具有大孔径、易修饰、物理化学稳定性等优点，介孔硅材料 SBA-15 通过水热反应合成。为了提高对 Cu 离子的吸附容量和选择性，采用锰负载和胺接枝（MN-SBA）对制备的 SBA-15 进行改性，然后用海藻酸钠（GMN-SBA）造粒。MN-SBA 对 Cu、Zn、Ni 和 Mn 等重金属的吸附容量分别为 2.11、1.24、1.74 和 1.25mmol/g，造粒后分别降至 1.23、0.68、0.86 和 0.65mmol/g。尽管 GMN-SBA 对重金属的吸附容量降低了 40-50%，但当应用于连续固定床柱吸附模式时，它可以实现易于再生和分离的过程。具体来说，结果表明 GMN-SBA 可以重复使用 5 次，同时保持超过 80%的吸附容量。固定床吸附结果通过结合线性驱动力近似（LDFA）模型的动态吸附模型得到了很好的解释。根据床长、进料浓度和流速对固定床吸附试验进行了模拟，结果表明突破时间在时间轴上发生了偏移。在多组分吸附中，LDFA 模型显示 Zn、Ni 和 Mn 的突破曲线出现了高过冲现象，而 Cu 则没有。这反映了 Cu 对 GMN-SBA 的高亲和力。
