A novel ion exchange system to purify mixed ISS waste water brines for chemical production and enhanced water recovery



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44th International Conference on Environmental Systems


The International Space Station water recovery system produces a sizable portion of waste water brine. This brine is highly toxic and contains a significant volume of water. With new biological techniques that do not require waste water chemical pretreatment, the resulting brine would be chromium-free, nitrate rich, and could be used for fertilizer recovery in future plant systems. Using a system of ion exchange resins may remove hardness, sulfate, phosphate and nitrate from these brines leaving only sodium and potassium chloride. At this point modern chlor-alkali cells can be utilized to produce a low salt stream as well as an acid and base stream. The first stream (low salt) can be used to gain higher water recovery through recycle to the water separation stage while the last two streams can be used to regenerate the ion exchange beds used here, as well as other ion exchange beds in the ISS. Conveniently these waste products from ion exchange regeneration would be suitable as plant fertilizer. In this report the performance of state of the art resins designed for high selectivity of target ions under brine conditions was determined. Using ersatz ISS waste water we can evaluate the performance of specific resins and calculate mass balances to determine resin effectiveness and process viability. If this system is feasible then we will be one step closer to closed loop environmental control and life support systems (ECLSS) for current or future applications.


The 44th International Conference on Environmental Systems was held in Tuscon, Arizona, USA on 13 July 2014 through 17 July 2014.
Griffin M. Lunn, QinetiQ North America, USA
LaShelle E. Spencer, QinetiQ North America, USA
Anna Maria J. Ruby, NASA Kennedy Space Center, USA
Andrew McCaskill, Florida Institute of Technology, USA