Progress, challenges, and prospects of MOF-based adsorbents for phosphate recovery from wastewater

Abstract

Phosphate is a vital component for the proper functioning of organisms. However, when excessive amounts of phosphate are introduced into aquatic environments, it can lead to eutrophication, which contributes to the formation of detrimental algal blooms. These blooms present significant threats to ecological balance, water quality, and human health. To mitigate and prevent eutrophication, the removal and recovery of phosphate is highly desired. The adsorption technique, utilizing a range of sorbents like activated carbon and natural minerals, proves to be a remarkably effective, economical, and eco-friendly approach used to eliminate phosphate from wastewater. Among them, metal-organic frameworks (MOFs) have garnered significant consideration recently as promising porous materials with potential environmental applications. MOFs possess exceptional characteristics, including substantial porosity, high surface area, controllable pore dimensions, unique architecture, flexible surface chemistry with diverse functional groups, and stability across a broad range of pH and temperature. These attributes make them highly suitable as adsorbents for phosphate recovery compared to other commonly utilized adsorbents. This review centers on the latest advancements in using MOFs for phosphate removal. It covers various aspects, including synthesis methods, properties, factors affecting phosphate removal, regeneration, and the underlying mechanisms involved in removing phosphate by these adsorbents. The review also addresses the challenges and limitations associated with the practical application of MOFs for phosphate recovery. Furthermore, it highlights potential avenues for future research aimed at advancing the use of MOFs in phosphate recovery.