Department of Environmental Engineering, Faculty of Engineering, Gebze Technical University, 41400 Gebze, Turkey; Department of Environmental Engineering, Faculty of Engineering and Natural Sciences, Bursa Technical University, 16310 Bursa, Turkey.
Department of Environmental Engineering, Faculty of Engineering, Gebze Technical University, 41400 Gebze, Turkey; Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, 51666-16471 Tabriz, Iran.
Adv Colloid Interface Sci. 2022 Feb;300:102598. doi: 10.1016/j.cis.2021.102598. Epub 2022 Jan 4.
Eutrophication is a widespread environmental challenge caused by excessive phosphate. Thus, wastewater engineers primarily aim to limit the phosphate concentration in water bodies. Layered double hydroxides (LDHs) are lamellar inorganic materials containing tunable brucite-like structures. This review discusses the fundamental aspects and latest developments in phosphate removal using LDH-based materials. Based on the divalent cations, Ca, Mg, and Zn-containing LDHs are largely used along with trivalent cations such as Al and Fe owing to their limited toxicities. However, classical LDHs are affected by the presence of co-existing anions, have a narrow working pH range, and have moderate adsorption capacities. Binary LDHs have been designed to be selective towards phosphate by the addition of a third metal such as Zr. Developing LDH composites with magnetic, polymeric or carbon materials are feasible approaches for increasing adsorption capacity, stability, and reusability of LDHs. Biochar as a carrier material for LDHs achieved remarkable phosphate adsorption performance and improved LDH dispersion, anion exchange capacity, and ease of separation. The use of recovered phosphate as an SRF, which is a type of bioavailable fertilizer, is a promising approach.
富营养化是由过量磷酸盐引起的一种广泛存在的环境挑战。因此，废水工程师主要致力于限制水体中的磷酸盐浓度。层状双氢氧化物（LDHs）是含有可调节水滑石结构的层状无机材料。本综述讨论了基于 LDH 的材料去除磷酸盐的基本方面和最新进展。基于二价阳离子，Ca、Mg 和 Zn 含量的 LDH 与 Al 和 Fe 等三价阳离子一起大量使用，因为它们的毒性有限。然而，经典 LDHs 受到共存阴离子的影响，工作 pH 范围较窄，吸附容量适中。通过添加第三种金属（如 Zr），设计了二元 LDH 以对磷酸盐具有选择性。通过与磁性、聚合物或碳材料复合开发 LDH 是提高 LDH 吸附容量、稳定性和可重复使用性的可行方法。将生物炭作为 LDH 的载体材料，实现了显著的磷酸盐吸附性能，并提高了 LDH 的分散性、阴离子交换能力和易于分离。将回收的磷酸盐作为一种 SRF（生物可利用肥料）使用是一种很有前途的方法。
