(373b) Membrane Material Development for Spaceflight Wastewater Applications

Membrane processes are a vital part of the water treatment arena and a continuing area of technology development. Reverse osmosis (RO) accounts for a large portion of this technology, but is generally limited by TDS levels >100. The driving force for RO is realized via a hydraulic pressure applied to the feed side of the membrane, and utilizes dense membranes that are often polymeric. Pervaporation is a membrane process that shares some similarities with RO. In pervaporation, the membranes are typically dense and polymeric, with some other materials (such as zeolites), also being utilized. The driving force is the key feature of pervaporation, which is realized by either a sweep gas or a vacuum pull on the permeate side of the membrane, requiring a condensation/capture method downstream. Pervaporation is attractive in that it can handle highly concentrated waste streams and also be tailored for removal of water or organics from the feed stream, depending on membrane properties. Our research focuses on improving pervaporation membranes in order to enhance longevity potential of the membranes and target highly concentrated waste streams, such as those present in waste streams found on the International Space Station.