Covalent organic frameworks as promising materials for the removal of metal and organic pollutants from water

Wastewater pollution with micropollutants (organic molecules, heavy metal ions, inorganics, and metabolites of these) in low to very low concentrations (ng/L to pg/L) is a serious contemporary problem that conventional water and wastewater treatment methods cannot efficiently resolve. For this effect, the adsorption and membrane-based technologies employing porous materials have been attracting great attention. Covalent Organic Frameworks (COFS), a new class of highly porous polymers, as part of Porous Organic Polymers (POPs) become superior candidates for application in separation processes and water purification due to their porosity, crystallinity, and good thermal and chemical stability. COFs are tested for water treatment and removal of many industrial pollutants such as dyes, pesticides, perfluorinated compounds, pharmaceutical pollutants, heavy metals, and radionuclides. Metal functionalized and loaded COFs were tested as well as also COFs performance in analytics. COFs-based membranes exhibit high selectivity in molecular separation and nanofiltration. Revised literature shows that COFs exhibit many advantages in micropollutant removal from water due to excellent and adjustable pore structure, porosity, and functionality but need to be further investigated. This review attempts to highlight the main advances in the use of COFs for water treatment and purification applications until early 2022.