Latest Progress and Perspectives in Layered Double Hydroxide-Based Adsorbents for Phosphate Pollution Removal from Wastewater

Abstract

Layered double hydroxides (LDHs) have attracted immense attention as a ′green adsorbent″ for removing and recovering phosphorus due to their large surface area and layered structure, exhibiting strong potential for phosphate pollution adsorption. The rational design of phosphorus (P) removal and recovery adsorbents will provide more feasibility and efficient performance. LDHs-based adsorbents for P removal were rarely investigated and summarized. Thus, this review systematically summarizes the synthetic methods, adsorbent types, and mechanisms of LDHs. Synthetic methods significantly affect the adsorption properties, specific surface area, morphology, and crystallinity of LDHs. The binary LDHs are classified into binary LDHs (Mg-, Ca-, and Zn-type), ternary LDHs, magnetic LDHs, and composite LDHs with biochar and polymers, which maintain the structural stability of LDH and adjust the charge density. This review briefly summarizes the phosphate pollution adsorption mechanisms of LDHs, including ion exchange and complexation. Finally, future challenges and perspectives are presented to provide new insights into future research on LDH-based phosphorus removal materials.