(619d) Novel Electrospun Membranes for Membrane Distillation
AIChE Annual Meeting
2021
2021 Annual Meeting
Separations Division
Surface Engineered and Responsive Membranes
Thursday, November 11, 2021 - 1:45pm to 2:10pm
We have developed a novel PVDF based electrospun membrane to simultaneously solve fouling and pore wetting. Initially a PVDF blended with etyltrimethylammonium bromide electrospun membrane was prepared. Next a second layer was electrospun consisting of PVDF. Negatively charged silica nanoparticles were attached to the PVDF blended with etyltrimethylammonium bromide electrospun membrane by electrostatic adsorption. This creates an amphiphobic surface. Finally, the unmodified PVDF fibers were modified by grafting poly(glycidyl methacrylate-sulfobetaine methacrylate) (zwitterions) to the surface of the PVDF layer. The novel bilayer electrospun membrane was tested using both synthetic and real produced water feed Streams.
Our novel bilayer electrospun membranes showed excellent fouling resistance and salt rejection when compared to base PVDF membrane and the amphiphobic membrane without zwitterion grafting. When challenged with real produced water, the bilayer membrane showed superior flux compared to the two other membranes due to the presence of an antifouling hydrated layer. In practice it will be necessary pretreat the feed prior to membrane distillation. Thus, we have explored the use of electrocoagulation prior to membrane distillation.
Here we have challenged our bilayer electrospun membranes with hydraulic fracturing produced water. These wastewaters are particularly fouling as they contain dissolved salts, polar and non-polar organic compounds as well as surfactants. We highlight the importance of tailoring the surface properties of the membrane. Similarly developing membranes for treating other wastewaters e.g. brackish water, agriculture and aquaculture wastewaters will also require tailoring the membrane surface properties based on the contaminants that lead to membrane fouling