Enhanced permeability of polyamide nanofiltration membranes via modification with a MOF-801/PEI functional intermediate layer
摘要
Water scarcity and water pollution are two major environmental issues facing all over the world. Membrane technology is an efficient and advanced wastewater treatment technology that has unique advantages in removing particulate matter, organic matter, microorganisms, and other pollutants. The present work report a high performance nanofiltration membrane for recycling and utilization of energy resources. The membrane was prepared by co-deposition dopamine and PEI in the PES based membrane as the intermediate layer, then spraying with different content of MOF-801. Subsequently, interfacial polymerization was carried out through piperazine and 1,3,5-benzenetricarbonyl trichloride. The obtained membrane was evaluated by testing the separation performance of Na2SO4, MgSO4, MgCl2 and NaCl aqueous solution. FTIR, CA, XPS, SEM, AFM were carried out to analysis the physical and chemical structures of membranes. The effects of dopamine co deposition, nanomaterial content, salt type, stability and anti-pollution were investigated. Results shown that the membrane exhibits excellent water flux and rejection after modified with MOF-801. The addition of 2% nanofiller could achieve the optimum performance. The water flux for Na2SO4, MgSO4, MgCl2 and NaCl were 21.19 L m−2 h−1 bar−1, 21.11 L m−2 h−1 bar−1, 22.18 L m−2 h−1 bar−1, 25.74 L m−2 h−1 bar−1, respectively. The membrane present great stability for the continuous test of 70 h. Additionally, the performance of membrane maintain a high water flux after three rounds of pollution and cleaning. This is the first time that MOF-801 has been used as an intermediate layer to prepare nanofiltration membranes, which providing new route for the preparation of high performance membrane.