Extracellular Polymeric Substance-Intercalated MXene Membranes Toward Removal of Emerging Contaminants

Resource recovery from excess sludge, specifically the extraction of extracellular polymeric substances (EPSs), has become a frontier issue; yet achieving high-value utilization of this recovered resource remains a key bottleneck. Two-dimensional MXene membranes show great potential for emerging contaminants (ECs) separation owing to their lamellar structure and tunable surface chemistry. In this study, biological macromolecule (BM)-intercalated MXene (BM-M) composite membranes were fabricated using practical EPSs and model EPSs such as sodium alginate (SA), bovine serum albumin (BSA), and silk fibroin (SF) as sustainable intercalators. The interlayer spacing, surface charge, hydrophilicity, mechanical strength, functional group of BM-M membranes and their EC removal behaviors were systematically investigated. The practical EPS performed better than the model EPS, highlighting the importance of molecular complexity in interlayer design. The practical EPS-intercalated MXene (EPS-M) membrane achieved the removal efficiencies of 64.0%, 90.2% and 67.5% for diethyl phthalate (DEP), erythromycin (ERY) and sulfamethoxazole (SMX), respectively. The separation mechanism of ECs mainly included electrostatic, sieving, hydrophobic, and hydrogen bonding. This work highlights the effectiveness of EPS intercalation in tailoring MXene membrane structure for the removal of diverse ECs.