Field-Induced Redistribution of Surfactants at the Oil/Water Interface Reduces Membrane Fouling on Electrically Conducting Carbon Nanotube UF Membranes

• DOI: 10.1021/acs.est.8b02578
• Publication Date: 2018-09-17T12:14:49Z
• Authors: Xiaobo Zhu; Alexander V. Dudc...; Chia Miang Khor; Xin He; Guy Z. Ramon; David Jassby
• Keywords: Membrane Fouling; Biofouling; Coalescence (physics); Produced water

Membrane-based treatment of oily wastewater remains a significant challenge, particularly under high salinity conditions. The main difficulty associated with this separation process is membrane fouling, mostly caused by wetting and coalescence emulsified oil droplets on the surface. In study, electrically conducting carbon nanotube-based ultrafiltration membranes were used to treat an suspension at ionic strengths as 100 mM. By tuning electrical potential applied surface, we demonstrate how fouling can be dramatically reduced, even Permeate water quality shown improve upon application negative potential. Using optical microscopy, observed dramatic changes in shape membrane/water interface response electric potential; change redistribution charged surfactant molecules oil/water external field. Specifically, using cathode repels away from oil/membrane interface, while anodic conditions lead increased concentrations. We speculate that molecule distribution responsible for surface tension which results decrease subsequent fouling. study offer attractive option when separating