A Gemini-Type Superwettable Separator for Consecutive Purification of Water and Oil Phases from Oil-Water Mixtures and Emulsions.

Oil pollution results from daily activities and a variety of industries have caused not only severe environmental problems but also wastage of valuable petrochemical resources. Separation based on superwettable materials holds promise; however, practical applications of a single type of superwettable materials were often limited due to their ability in treatment of complicated oil-water systems. Herein, a Gemini-type separator was created through the cooperation of two kinds of superwettable sand particles with opposite wettability, i. e., one is superhydrophobic whereas the other is superhydrophilic. Cooperatively by the two types of superwettable sand, consecutive separation and purification of both water and oil phases from complicated oil-water systems (e. g., water mixed with a lighter or denser oil, water emulsified in oil, oil emulsified in water, and/or a combination of them in one batch) could be achieved with high flux and superior efficiency just in one single operation unit.