Conventional oil-water separation methods are inefficient since they break down a given “primary” phase into two “secondary” phases, one is richer and the other one is poorer in the “secondary” phase of the “primary” phase. As such, neither oil is recovered as a readily de-watered stream nor is water recovered as a readily de-oiled stream. However, de-watering and de-oiling of “oil-water” streams are synonymous, and therefore they should be simultaneously targeted by an efficient method. There are provided herein systems and methods to effectively treat “oil-water” streams by simultaneously de-watering the oil phase and de-oiling the water phase, de-scaling the de-oiled water phase, and de-salting the de-scaled water phase.