Removal of ultraviolet filter from water by electro-ultrafiltration Original Research Article

Ultraviolet (UV) filters represent a new class of micropollutants in water. Electro-ultrafiltration (EUF) process was used to separate 4-methylbenzylidene camphor (4-MBC) from water by applying an electric field across the membrane to remove these substances more effectively and minimize fouling. The modification of polyvinylidene fluoride (PVDF) membrane, the effects of the electric field on the filtration performance, including resistance and retention, and possible intermediates produced during EUF process were studied thoroughly. The membrane had a rougher surface and the pore size increased due to the modifications of PVDF membrane induced by the electric field. The decrease in contact angle demonstrated the improvement of hydrophilicity in the PVDF membrane surface after the EUF treatment. The results clearly indicate that the combination of the electric field with ultrafiltration could increase 4-MBC rejection and reduce filtration resistance. The mechanism of 4-MBC degradation in the electrofiltration was examined theoretically by calculating the frontier electron densities of the 4-MBC molecule. The C5 atom in the 4-MBC structure was demonstrated to be the most reactive site, which was consistent with the intermediate results identified by gas chromatography–mass spectrometry (GC–MS) analysis.