Journal
JOURNAL OF MEMBRANE SCIENCE
Volume 459, Issue -, Pages 143-156Publisher
ELSEVIER
DOI: 10.1016/j.memsci.2014.02.017
Keywords
Ultrafiltration membrane; Organic fouling; Surface charge; Capacitive fouling mitigation
Categories
Funding
- Harvard University's Center for the Environment
Ask authors/readers for more resources
Organic fouling of ultrafiltration (UP) membranes results in decreased water flux and increased energy requirements. Modification of UP membrane surfaces is one possible method to mitigate natural organic matter (NOM) fouling, yet to date; most modifications have been passive. In this study, we investigate the use of a carbon nanotube-polyvinylidene fluoride (CNT-PVDF) porous non-Faradaic cathode on top of a OF membrane to actively produce negative surface charges via capacitive charging. The study is divided into three elements: (1) modification of the OF system with the capacitive CNT-PVDF electrodes and determination of the optimal electrode-membrane configuration, (2) analysis of the fouling mitigation mechanism, and (3) evaluation of the practical potential of capacitive fouling reduction. All experiments were completed in the cross-flow configuration. The optimal electrode-membrane configuration for organic fouling reduction was when the permeate first flowed through the porous anode, then the CNT-PVDF cathode, and finally the polyethersulfone (PBS) UP membrane. The extent of capacitive fouling reduction was determined to be a function of anode material, ionic strength, and cathode potential. The primary fouling reduction mechanism is the potential-induced cathodic negative surface charges that increase the Derjaguin-Landau-Verwey-Overbeek (DLVO) energy barrier and decrease the collision efficiency of negatively-charged organic matter with the membrane surface. The capacitive system has potential to reduce energy requirements by up to 2-fold as compared to the unmodified OF system when challenged with 10 ppm NOM solutions at low ionic strength. (C) 2014 Elsevier B.V. All rights reserved
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available