Tailoring of polysulfate/polyvinylpyrrolidone membrane structure via NIPS coupled physical aging technique for high-performance dye/salt separation

Tight ultrafiltration (TUF) membranes have been proposed as an effective candidate for the treatment of textile wastewater with high salinity. In this study, a novel polysulfate (PSE)-based TUF membrane was prepared by coupling the non-solvent induced phase separation (NIPS) process with the physical aging method. The polyvinylpyrrolidone (PVP) was adopted to tailor the micro-/nanostructure of the fabricated membranes. Accordingly, the molecular weight cut-off (MWCO) of the membrane can be tuned from 293.8 to 3.7 kDa. Endowed with the high porosity and small pore size, the optimized PSE/PVP blend membrane (a MWCO of 3.9 kDa) was applied for removal of dyes from dye/salt aqueous solution, which offered top-tier overall performance, e.g., a pure water flux of 70.7 L*m−2*h−1, CR/NaCl selectivity of 494.3, CR/Na2SO4 selectivity of 42.6, long-term running stability, and excellent antifouling performance. Therefore, our study establishes a simple avenue to fabricate a high-performance TUF membrane for practical textile wastewater treatment.