Pressure-driven distillation (PD) is an emerging process with the potential to improve the effectiveness of water recovery systems. In PD, pressure is used to drive water vapor transport through a porous air-trapping membrane. PD can achieve high removal of all non-volatile contaminants and uses robust hydrophobic membrane materials. Because PD is a pressure-driven process, it can also operate with high efficiency comparable to that of widely used reverse osmosis systems, and it has the potential to directly replace reverse osmosis in a typical water-reuse treatment scheme. This opens a wide variety of potential water reuse applications requiring high-purity treated water including water recycling systems used in short- and long-term space travel. PD membranes are highly resistant to oxidation and extreme pH conditions, allowing for the cleaning of foulants on the membrane surface. In this work, we show the advantages of PD, along with its main failure mechanisms and how to mitigate them. We demonstrate PD membranes can remove contaminants seen in the humidity condensate stream, such as DMSD, to decrease the load on the multi-filtration beds during future exploration missions. The work presented here aims to enhance water recovery systems in current and future exploration missions by offering an alternative method for urine treatment and a supplemental, lightweight treatment technology for the treatment of humidity condensate.
Lopez et al. (Sun,) studied this question.