High Capacity Sorbents for Removal of Problematic Contaminants from Processed Wastewater

Water recovery from wastewater sources is a key to long duration human exploration missions.nbsp; Regenerative systems are utilized on the International Space Station (ISS) to recycle water from humidity condensate and urine. However, two organic compounds, dimethylsilanediol (DMSD) and dimethyl sulfone (DMSO2), are problematic to water processor assembly (WPA) in the ISS. DMSD is a silicon-containing degradation byproduct from siloxane-based compounds. It can contaminate ISS potable water quality standards over time, requiring premature multi-filtration (MF) bed replacement. DMSO2 is a sulfur-containing metabolic byproduct that accumulates in the oxygen generation assemblyrsquo;s (OGA) water recirculation loop and ends up in the hydrogen product stream, and slowly poisons the Sabatier catalyst over time by sulfur exposure. Hence, there is a need to develop high capacity sorbents that remove these contaminants while being compatible with the ISS WPA. This will benefit both current manned and future exploration missions.nbsp;In this proposed STTR project TDA Research in collaboration with the University of Puerto Rico Mayaguez (UPRM), will develop highly efficient nanoporous sorbents to remove DMSD and DMSO2 removal from processed waste water from the WPA. These sorbent beds will be sized and integrated with the MF beds and replaced under regular maintenance schedules. In Phase I we will optimize the sorbentrsquo;s formulations to increase their capacity for DMSD and DMSO2 adsorption. We will then complete the initial scale-up of the sorbent to increase the preparation batch size by 2-5x and demonstrate DMSD and DMSO2 removal under representative conditions in a fixed bed adsorption process, elevating the TRL to 4. In Phase II, we will further scale-up the sorbent production and build a high fidelity prototype assembly, and demonstrate the sorbent beds under conditions representative of the MF beds in the WPA, elevating the TRL to 6.