The proposal for the completely closed system in the Columbus Space Station

Abstract For the European Space Agency, a preliminary investigation has been made on the possibilities of recycling of water in manned space vehicles. One of the purposes was to find a feasible method of water recycling, where 98% of the water is recycled, producing both drinking water and hygiene water of a standard equivalent to the WHO standards for drinking water. Only physical-chemical methods should be used, and the waste should be brought into a storable form. The method must be able to operate under microgravity conditions and must have a low energy requirement. The investigation has shown that no single unit operation alone can produce the required water quality. A system including: Pretreatment with acid and filtration, Acid reverse osmosis, Oxidation with H2O2 and UV light, Neutral reverse osmosis, is recommended for all waste waters other than urine. Urine and reject from acid reverse osmosis are distilled on a centrifugal force vapour compression unit below 60°C. The main chemical and bacteriological problems in the processing are described.