Membrane Distillation Bags for Water Recovery in Trash Compaction and Processing Systems

Abstract

The National Aeronautics and Space Administration’s (NASA) crewed spacecraft use containers to store waste derived from food, water, and other supplies. The trash bags occupy a large volume and present a significant logistical concern, especially for long duration missions. In order to reduce the volume of waste, control microbial growth and recover water, NASA has developed a heat melt compactor (HMC) unit. In this work, trash bags fabricated using selectively water permeable polymeric membranes were tested in a heat melt compactor test unit. Recovery of water from solid waste and encapsulation of the waste after water recovery was achieved. Water was recovered from a waste simulant at various temperatures, and the total organic content (TOC) in recovered water was analyzed. The results showed up to a 50 - 85% reduction in TOC for the reclaimed water using membrane distillation bags (MD-BAGs) depending on the HMC process temperatures, the vacuum used, and pressure applied on the bag.