Fabrication of hierarchical layer-by-layer membrane as the photocatalytic degradation of foulants and effective mitigation of membrane fouling for wastewater treatment

Abstract

A polyvinylidene fluoride plate sheet membrane coated 3D TiO₂/poly (sodium styrenesulfonate) (PSS) photocatalyst layers were fabricated via dip-coating layer-by-layer (LbL) assembly. Cationic TiO₂ and anionic PSS were alternately stacked on the support membrane via electrostatic interactions. The obtained modified membrane with (TiO₂/PSS)₇ exhibited optimal versatility under ultraviolet light irradiation in both dead-end and membrane reactor, which showed superior Lanasol Blue 3R (LB) removal rate to membrane filtration and biodegradation. The modified membranes (MM) exhibited good performance in terms of photocatalytic activity of foulant degradation and mitigation of membrane fouling in a membrane reactor. The obtained MM with (TiO₂/PSS)₇ exhibited optimal versatility under ultraviolet light irradiation in both dead-end and membrane reactors and superior Lanasol Blue 3R removal rate in membrane filtration and biodegradation. The MM (TiO₂/PSS)₇ possessed excellent antifouling properties by using bovine serum albumin (BSA), as evidenced by the extended Derjaguin-Landau-Verwey-Overbeek theory. Additionally, the TiO₂/PSS membrane showed good self-cleaning ability, and the foulants on the membrane surface could be degraded using ultraviolet light irradiation.

Keywords: Anti-fouling performance; Layer-by-layer; Photocatalytic modification; Self-cleaning; xDLVO.