Thin film composite membrane with self-cleaning properties via a catalytic interlayer for dye wastewater treatment

Fouling control is the most critical concern in the implementation of nanofiltration (NF) for dye wastewater treatment . In this study, integration of NF and Fenton-like advanced oxidation was realized by tailoring a thin film composite NF membrane (TFNi) with in situ synthesized PDA/MnO 2 interlayer. TFNi was optimized by controlling the amount of MnO 2 nanoparticles incorporated within the interlayer which endowed the membrane with self-cleaning property. Besides it improved the membrane surface hydrophilicity and optimized the water transport path, resulting in alleviated fouling risks and an enhanced water permeance of 24 ± 2 L m −2  h −1 bar −1 compared to the control membrane. Fouling and subsequent chemical cleaning experiments were carried out on TFNi under various water chemistry conditions to elucidate the underlying mechanisms governing the self-cleaning properties. Accordingly, a high flux recovery ratio ( FRR ) (above 95%) was maintained thanks to the generation of free radicals by MnO 2 –H 2 O 2 system which was validated by determining the free radical scavenging activities. Moreover, the interlayer confined radicals can facilitate the decomposition of foulants on TFNi. Conclusively, H 2 O 2 -initiated self-cleaning of TFNi can be of great prospect for the efficient treatment of dye wastewater via in-situ generated free radicals.