2014-10-212014-10-212014-07-13978-0-692-38220-2ICES-2014-135http://hdl.handle.net/2346/59699Tucson, ArizonaThe 44th International Conference on Environmental Systems was held in Tuscon, Arizona, USA on 13 July 2014 through 17 July 2014.Tony Rector, Hamilton Sundstrand Space Systems International, USACarol Metselaar, Hamilton Sundstrand Space Systems International, USABarbara Peyton, Hamilton Sundstrand Space Systems International, USAJohn Steele, Hamilton Sundstrand Space Systems International, USAWilliam Michalek, Umpqua Research Company, USAElizabeth Bowman, The Boeing Company, USAMark Wilson, The Boeing Company, USADaniel Gazda, Wyle, USALayne Carter, NASA MSFC, USASince activation of the Water Processor Assembly (WPA) on the International Space Station (ISS) in November of 2008, there have been three events in which the TOC (Total Organic Carbon) in the product water has increased to approximately 3 mg/L and has subsequently recovered. Analysis of the product water in 2010 identified the primary component of the TOC as dimethylsilanediol (DMSD). An investigation into the fate of DMSD in the WPA ultimately determined that replacement of both Multifiltration (MF) Beds is the solution to recovering product water quality. The MF Beds were designed to ensure that ionic breakthrough occurs before organic breakthrough. However, DMSD saturated both MF Beds in the series, requiring removal and replacement of both MF Beds with significant life remaining. Analysis of the MF Beds determined that the adsorbent was not effectively removing DMSD, trimethylsilanol, various polydimethylsiloxanes, or dimethylsulfone. Coupled with the fact that the current adsorbent is now obsolete, the authors evaluated various media to identify a replacement adsorbent as well as media with greater capacity for these problematic organic contaminants. This paper provides the results and recommendations of this collaborative study.application/pdfengPresentation