Regeneration of water at space stations

Electrochemical treatment of artificial humidity condensate by large-scale boron doped diamond electrode

“…It is the most realistic and economical way to treat it for the supplement of drinking water because of its relatively clean quality [2]. Sorption-catalytic oxidation of HC was employed with high efficiency, where Pt was used as the catalyst and oxygen as the oxidizer [3,4]. However, the method suffered from high consumption of adsorbents and energy, and the operating cost was high.…”

Impact of fouling, cleaning and faecal contamination on the separation of water from urine using thermally driven membrane separation

“…Tun et al ( 14 ) instead concentrated ammonia nitrogen within source separated urine by favouring water transport through direct contact MD. Whilst these few studies, together with the successful use of MD for water reclamation from urine in European Space Stations ( 15 ), demonstrates conceptual viability, there remains limited evidence in the literature regarding the impact of fouling or faecal contamination which will inevitably present operational challenges at the decentralised scale. The aim of this study is therefore to study membrane distillation as an enabling technology for non- sewered sanitation, to provide high quality water separation from faecally contaminated urine using waste heat.…”

Ultrafiltration pretreatment enhances membrane distillation flux, resilience and permeate quality during water recovery from concentrated blackwater (urine/faeces)

“…3 µm stretched pore length). Importantly, in this study, consistent permeation at high concentration factors (or product water recoveries) demonstrates viability, which was endorsed by the use of membrane distillation for water reclamation in limited space applications [12] .

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“…These low MW bile salts are responsible for the significant reduction in surface tension (55mN m −1 versus 73mN m −1 for water) due to their amphiphilic and hydrophobic contributions [28] . Regardless of this reduction in fluid surface tension, Kamranvand et al [19] did not observe wetting during the membrane distillation of urine even with a membrane of coarse pore radius, indicating reasonable process resilience to this specific organic matrix; these observations support the rationale for adoption of MD for direct potable reuse in space missions [12] . However, faecal contamination of urine did reduce membrane permeability due to the formation of a particle cake which introduced two effects: (i) an initial reduction to heat and mass transfer, which lowered water flux; and (ii) the subsequent introduction of wetting, which diminished water quality.…”