Electrospun nanofiber membrane for membrane adsorption, membrane contactor and fouling mitigation in ultrafiltration

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Nano-scale materials can be rationally designed to exhibit novel and significantly improved *physical and chemical properties. Polymer nanofibers, an important class of nano-materials, have attracted increasing attention during the past decade.**In particular, electro-spun nanofiber membranes (ENMs) have already been proven to be applicable in a variety of membrane processes for water treatment, such as MF, UF, NF, MD, FO, PRO, membrane absorption and membrane air stripping in the laboratory scale. The proposed project aims to widen the scope of the applicability of ENMs as filtration membrane for water and gas treatment even further. Water treatment by ENMs is now on the verge of commercialization. There are companies who are aiming at the commercialization of nanofiber membranes for water treatment (e.g. Xanofi, founded in 2010 in NC, USA). The proposed project will contribute to the future commercialization of ENMs by demonstrating a variety of novel applications of ENMs.**Thus, the objectives of this research are:*1) To fabricate and test the metal oxide nanoparticles incorporated electro-spun nanofiber membranes (ENMs) (hereafter called Mixed Matrix ENMs (MMENMs)) for the removal of arsenics from water by membrane adsorption (MA)*2) To fabricate and test ENMs in membrane contactor (MC) application for capturing CO2 from CO2/N2 gas mixtures*3) To fabricate ENMs aligned parallel for fouling mitigation and washing enhancement in ultrafiltration applications ***In the last few decades, arsenic contamination in natural water has raised significant environmental and public health concerns because of its high toxicity, accumulation in human body and carcinogenicity. Recently, the development of affinity membrane provided an effective method for arsenic removal under low pressure. In view of very high porosity and interconnectivity, a much higher flux is expected by ENMs when they are used in MA.**Membrane contactor (MC) is a process in which gas and liquid flow on the opposite sides of a porous membrane; a gaseous component diffuses through the membrane pore from the gas to liquid phase where the gas is absorbed by the absorbent in the liquid. One of its applications is CO2 removal from natural and flue gas. Membrane contactor can provide contact area per unit volume 4 to 30 times higher than the conventional separation columns. ENM is an excellent candidate for membranes for MC for its high porosity and hydrophobicity.**An observation was made recently during the development of metal oxide incorporated polymeric membranes; i.e. polymer nodules were aligned parallel, and very clear patterns were observed by the Atomic Force Microscopy (AFM) at the membrane surface.*It was also found that the membrane fouling could be reduced substantially when the feed flow was oriented perpendicular to the patterned lines, while membrane washing was effective when the feed flow was oriented parallel to the patterned lines. Parallel alignment of nanofibers in ENM will provide a perfect pattern at the membrane surface and thus enhance the above effects.