Characterization of Heat Melt Compactor (HMC) Product Water

The Heat Melt Compactor (HMC) is designed to sterilize and process solid wastes produced during space missions. Benefits of the HMC include reduction of biohazards to the crew, reduction in volume of wastes that would otherwise require storage, production of radiation shielding tiles, and recovery of water and other resources. Water reuse is critical onboard spacecraft; it reduces the need for resupply missions and saves valuable storage space. The main sources of water in HMC batches are food, beverages, wet clothing, and personal hygiene items such as shampoo, disinfecting wipes, and toothpaste. Water reclaimed by the HMC was analyzed for concentrations of Na, NH4, K, Mg, Ca, Cl, NO2, Br, NO3, PO4, SO4, total organic carbon (TOC), total inorganic carbon (TIC), % total solids, and pH. Batches inoculated with microbes for sterilization testing had significantly higher TOC concentrations than non-inoculated batches. The data are discussed in relation to drinking water standards and the current water input criteria established for the International Space Station Water Processor Assembly system.