Advantages of TiO2/carbon nanotube modified photocatalytic membranes in the purification of oil-in-water emulsions

For the effective purification of emulsified oil contaminated waters advanced treatment methods have to be applied, such as membrane filtration, which is able to eliminate macro-, and even nanoscale oil droplets, however, membrane fouling is still a major problem, which prevents economic utilization. Therefore, fouling mitigation is one of the most important aspects in the field of membrane separation developments. In the present study, solely TiO2 and TiO2/carbon nanotubes (CNT) composite modified PVDF membranes were prepared and used to purify oil-in-water emulsions. Achievable fluxes, reversible and irreversible filtration resistances, fouling models, filtration efficiencies and photocatalytic activities were compared in case of different nanomaterial covered and unmodified PVDF membranes. Applying either solely TiO2 or solely CNT coating resulted in the significant reduction of total filtration resistance in both cases, but the combination of the two components (TiO2 with 1 wt% CNT) resulted in by far the highest flux and lowest resistance, meanwhile, the enhanced photocatalytic efficiency of the composite was also achieved. To the best of our knowledge, this study demonstrates the beneficial effects of the combination of TiO2 and CNT nanomaterials for the first time in the field of membrane separation of oil-in-water emulsions. doi: 10.2166/ws.2018.172 s://iwaponline.com/ws/article-pdf/19/4/1167/593586/ws019041167.pdf Gábor Veréb (corresponding author) Viktória Kálmán Szabolcs Kertész Sándor Beszédes Cecilia Hodúr Zsuzsanna László Institute of Process Engineering, Faculty of Engineering, University of Szeged, Moszkvai Blvd. 9, Szeged H-6725, Hungary E-mail: verebg@mk.u-szeged.hu Tamás Gyulavári Gábor Kovács Klára Hernádi Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Sq. 1, Szeged H-6720, Hungary Zsolt Pap Cecilia Hodúr Institute of Environmental Science and Technology, University of Szeged, Tisza Lajos Blvd. 103, Szeged H-6720, Hungary