Covalent Organic Framework Membrane for Efficient Removal of Emerging Trace Organic Contaminants from Water Environment

Abstract

Abstract Emerging trace organic contaminants (TrOCs) are harmful pollutants that accumulate over time and pose serious potential hazards to human health and the ecosystem. Membrane technology provides a promising and sustainable method to remove them from water environment. However, the pore sizes of most commercial membranes are larger than the molecular size of most TrOCs, making it challenging to achieve effective interception. To address this problem, we proposed a side-chain engineering strategy to regulate the pore size of covalent organic framework membranes (COMs) from mesopore to micropore by introducing alkyl chains (Cn) of varying lengths into their pore surfaces. The Cn-COMs demonstrated efficient interception of various organic pollutants, including citrate esters, nitro polycyclic aromatic hydrocarbons, organophosphate esters, and pesticides, even those as small as 0.35 nm, with a rejection rate greater than 99% and corresponding flux higher than 110 kg·m− 2·h− 1·MPa− 1, which cannot be achieved by any commercial membranes. This work provides a new avenue for effectively removing different types of organic pollutants from water resources to ensure the safety and sustainability of our water supply.