Integrated solar-driven photocatalytic membrane distillation for synergistic removal of organics and desalination towards hypersaline organic wastewater treatment

High-salinity organic wastewater poses significant challenges to conventional treatment processes due to its complex composition, persistent organic compounds, and salinity-induced inhibition. Membrane distillation (MD) offers promise for hypersaline wastewater treatment with near-complete salt rejection. However, its limited organic removal capacity, especially for semi-volatile organic compounds (SVOCs) and other refractory organics, allows partial pollutant permeation, causing membrane fouling and wetting risks. To address this, we engineered a dual functional BiOClBr@PTFE composite membrane that integrates visible-light driven photocatalysis with MD for simultaneous organic degradation and desalination. The catalyst is immobilized onto the PTFE membrane through a filtration–spraying–crosslinking strategy, forming a robust structure that ensures high stability under extreme environmental conditions. In static tests, the resultant BiOClBr@PTFE membrane demonstrated excellent degradation efficiency (>98 %) for various organic pollutants, including bisphenol A (BPA), phenol and methylene blue (MB). Under dynamic photocatalytic-MD operation, it maintained stable water flux (18.08 kg m⁻² h⁻¹), organic degradation above 95 %, and salt rejection above 99.9 %. Electron paramagnetic resonance (EPR) and scavenger studies identified superoxide radicals (O₂^−•) as the dominant reactive species. Long-term testing with real textile wastewater confirmed practical viability. This work establishes a scalable strategy for integrated organics/salts removal, advancing solar-driven membrane distillation toward zero liquid discharge (ZLD) of hypersaline wastewater.