Key Laboratory of Metallurgical Emission Reduction & Resources Recycling, Anhui University of Technology, Ministry of Education, 243002 Maanshan, Anhui, China; School of Metallurgical Engineering, Anhui University of Technology, 243032 Maanshan, Anhui, China; Anhui Xinchuang Energy Saving & Environmental Protection Science & Technology Co. Ltd., 243071 Maanshan, Anhui, China.
School of Metallurgical Engineering, Anhui University of Technology, 243032 Maanshan, Anhui, China.
Int J Biol Macromol. 2020 Dec 1;164:4423-4434. doi: 10.1016/j.ijbiomac.2020.09.046. Epub 2020 Sep 13.
With the development of modern industry, heavy metal pollution is one of the most important environmental issues. Due to its simplicity and low-cost, adsorption is considered as a green and environmental friendly method to remove heavy metals from industrial effluents. Sodium alginate is a natural polysaccharide, which consists of abundant hydroxyl and carboxyl groups, has been widely reported as the raw material for the adsorption of heavy metals from aqueous solutions. By surface grafting and cross-linking, adsorbents synthesized from sodium alginate have exhibited large uptake capacities as well as high removal rates for heavy metal ions. However, the poor physical strength and plain thermostability have significantly limited the utilization of sodium alginate based materials in industrial applications. Moreover, reductions of specific metal ions were observed in some studies, of which the reduction mechanism is not clearly clarified. In this work, the development of sodium alginate based adsorbents was summarized, including the physicochemical properties of the polymer, the modification of sodium alginate, sodium alginate based composite materials, and the adsorption behaviors as well as the mechanism. Chelation, electrostatic interaction, ion exchange, reduction and photocatalytic reduction were involved in the adsorption process, which can be determined by chemical characterization with further elucidation by density functional theory calculation. Finally, the limitations of sodium alginate based adsorbents were revealed with suggestions for future research.
随着现代工业的发展，重金属污染是最重要的环境问题之一。由于其简单性和低成本，吸附被认为是一种从工业废水中去除重金属的绿色环保方法。海藻酸钠是一种天然多糖，由丰富的羟基和羧基组成，已被广泛报道为从水溶液中吸附重金属的原料。通过表面接枝和交联，由海藻酸钠合成的吸附剂表现出较大的重金属离子吸附容量和较高的去除率。然而，较差的物理强度和简单的热稳定性显著限制了基于海藻酸钠的材料在工业应用中的利用。此外，在一些研究中观察到特定金属离子的减少，其减少机制尚不清楚。在这项工作中，总结了基于海藻酸钠的吸附剂的发展，包括聚合物的物理化学性质、海藻酸钠的修饰、海藻酸钠基复合材料、吸附行为和机制。螯合、静电相互作用、离子交换、还原和光催化还原都参与了吸附过程，可以通过化学特性进一步通过密度泛函理论计算来阐明。最后，揭示了基于海藻酸钠的吸附剂的局限性，并对未来的研究提出了建议。
