Modified Resin Coalescer for Oil-in-Water Emulsion Treatment: Effect of Operating Conditions on Oil Removal Performance

The application of modified resin as a filter medium treating the anionic surfactant stabilized oil-in-water emulsion was investigated. In this study, emulsion breaking was accelerated by the grafting cetyltrimethylammonium bromide on polystyrene resin, so the need for expensive specific chemicals was eliminated. The results indicated that, as a new type of coalescence material, the modified resin has incomparable advantages over polypropylene, ceramic, and activated carbon. A series of experiments were performed to evaluate the effect of flow velocity, bed height, oil concentration, temperature, and pH value on the oil removal performance of the modified resin coalescer. More than 80% of emulsified oil was removed under optimal operating conditions: flow velocity 60-180 mL/h, bed height 20-40 cm, temperature 20-60 degrees C, and pH value 2-10. The results further indicated that modified resin bed coalescer is feasible to be used in the treatment of oil-in-water emulsion due to integration of both advantages of chemical demulsification and coalescence process.