Brine Dewatering Using Ultrasonic Nebulization

Recovery of water from brine is critically important for manned space exploration. Resupply of water is prohibitively costly for extended missions. It is anticipated that NASA will pool urine, hygiene water and humidity condensate into a combined waste stream that will subsequently be concentrated into a brine while recovering some but not all of the water, 90-95%. The concentrated brine that results from primary water recovery systems contains a significant amount of water. The proposed innovation will recover virtually all of the remaining water. This will be accomplished by ultrasonically creating nebulized droplets of the brine that can be readily dried under a partial vacuum with moderate temperature microwave heating. The process bears some resemblance to spray drying, but uses much smaller droplets (1.6 ýým as compared to ~100 ýým). Small droplets enable quicker drying due to their high relative surface area. This is particularly important when drying wastewater brines which contain ingredients that are thermally labile and require drying at relatively low temperatures. The proposed system has no nozzles to become plugged, requires no chemical additives, uses a minimal amount of power, is simple and small, requires minimal astronaut attention and uses a continuous, closed cycle process that is gravity independent.