(212h) Oil Recovery from Produced Water Via Selective Oil Filtration

High-efficiency separations of oil-water emulsions are crucial to the design and development of treatment trains for the beneficial reuse of high-strength industrial wastewaters like produced water. While microfiltration and ultrafiltration crossflow membranes can achieve low minimum droplet removal (<1 μm) and high oil removals (~99%), they often experience rapid viscous fouling of the membrane surface. Selective oil filtration is a promising membrane-based approach in which oil permeates through the membrane surface instead of water. The process differs from traditional membrane-based oil-water separations by exploiting the preferential wetting of the membrane surface, minimizing viscous fouling, and generating a high-quality oil permeate stream. Our previous research has observed encouraging results with synthetic oil-water emulsions (e.g., Isopar, soybean oil, motor oils) over a range of operating parameters (e.g., transmembrane pressure, influent flow rate) and solution characteristics (e.g., oil concentration, viscosity, interfacial tension). These studies with synthetic oil-water emulsions have provided mechanistic insight and a fundamental understanding of the process. Yet, few studies have investigated selective oil filtration utilizing real industrial wastewaters. In this study, we apply the fundamental insights that we have gained using model systems to understand and optimize system performance with real waters. In doing so, we enhance our understanding of both the efficacy and opportunity space for selective oil filtration.