Wetting resistance of commercial membranes in waste streams containing surfactants and oil in membrane distillation

Watermanagement is becoming increasingly challenging and several technologies, including membrane distillation (MD) are emerging. This technology is less affected by salinity compared to reverse osmosis and is able to treat brines up to saturation. The focus ofMD research recently shifted fromseawater desalination to industrial applications out of the scope of reverse osmosis. Inmany of these applications, surfactants or oil traces are present in the feed stream, lowering the surface tension and increasing the risk formembranewetting. In this study, the technological boundaries of MD in the presence of surfactants are investigated using surface tension, contact angle and liquid entry pressuremeasurements togetherwith lab-scaleMDexperiments to predict thewetting resistance of differentmembranes. Synthetic NaCl solutions mixed with sodium dodecyl sulfate (SDS) were used as feed solution. The limiting surfactant concentration was found to be dependent on the surface chemistry of the membrane, and increased with increasing hydrophobicity and oleophobicity. Additionally, a hexadecane/SDS emulsion was prepared with a composition simulating produced water, a waste stream in the oil and gas sector. When hexadecane is present in the emulsion, oleophobic membranes are able to resist wetting, whereas polytetrafluoretheen (PTFE) is gradually wetted by the feed liquid. Keywords:

Publication year:2017

BOF-keylabel:yes

IOF-keylabel:yes

BOF-publication weight:1

CSS-citation score:2

Authors:International

Authors from:Government, Higher Education