{"key":"water","title":"Water: the autonomous water cycle","kanji":"水","one_line":"Recycle first, sense everything, and make only the residual from rain, sea or air.","thesis":"A fully automated water layer is a loop, not a source: grey, yellow, brown and condensate streams are separated at the source, regenerated to the quality each use needs, and released only by a fail-closed sensor verdict, as the ISS does at 98%. Recovery is the master variable, because every point of net recovery shrinks the make-up source; at 90% net, a 4-person desert home needs about 44 L/day, not 320. The non-obvious ranking is by kWh per litre: rain and fog are almost free, any saline water desalinates at 0.003-0.0055 kWh/L, and atmospheric harvesting costs 0.4-5 kWh/L, so AWH belongs only where nothing liquid exists, and even then the farm's humid air and the heat pump's waste heat are better feedstocks than desert air. The binding constraints are not yield but brine chemistry, regrowth in storage, sensor-based safety and service logistics, which is where every documented failure (SOURCE in Allensworth, the ISS toilet and purge pumps, the Autarky toilet) actually happened.","subsystems":[{"id":"WATER-S1","name":"Sources: harvest liquid water the site already offers","function":"Bring new water into the loop only to cover losses (evaporation, biomass export, brine, leaks) and drinking, ranked by energy per litre.","how_it_works":"Rain capture is gravity plus a first-flush diverter: yield = roof area x rainfall x runoff coefficient, energy near zero. Fog nets intercept 1-40 um droplets carried by wind through a mesh; impaction efficiency depends on fibre diameter, shade coefficient and wind speed, so yield is extremely site specific. Dew condensers are radiatively cooled surfaces that drop below the dew point at night; the cooling budget (tens of W/m2 at best) divided by latent heat (about 2.45 MJ/kg) caps yield below about 1 L/m2/night before convective losses. Wells and springs need only pumping (about 0.0027 kWh per m3 per metre of lift at 100% efficiency) but need quality screening for arsenic, fluoride, nitrate and salinity.","options":[{"name":"Rooftop rain capture with first-flush and covered cistern","principle":"Gravity collection from the folded roof facets into a gutter, first-flush diversion, sediment trap, dark cistern","maturity":"COMMERCIAL","trl":9,"trl_why":"Millennia of practice; standard products and codes in most jurisdictions.","key_numbers":[{"label":"Yield formula","value":"A x P x C","unit":"L/yr (A m2, P mm/yr, C 0.75-0.9)","basis":"calculated","sources":["src-anyground-v3"]},{"label":"YOSHI-4 roof 40 m2 at 100 mm/yr desert","value":3200,"unit":"L/yr","basis":"calculated","sources":["src-anyground-v3"]},{"label":"Same roof at 800 mm/yr temperate","value":25600,"unit":"L/yr","basis":"calculated","sources":["src-anyground-v3"]}],"best_for":"E1 rooftop, E2 forest, E5 mountain, E6 coast, E7 steppe; minimal value in E3 desert","limits":"Seasonal; storage-bound; roof materials (bitumen, treated timber, Zn) and bird droppings require treatment before potable use."},{"name":"Fog mesh / fog harp on a Miura wing","principle":"Inertial impaction of wind-borne fog droplets on a vertical mesh, gravity drainage to gutter","maturity":"COMMERCIAL","trl":9,"trl_why":"Decades of operational projects in Chile, Peru, Morocco, Oman; yield is the uncertainty, not the technology.","key_numbers":[{"label":"Typical operational yearly average","value":"3-10","unit":"L/m2 mesh/day","basis":"measured","sources":["src-klemm-2012"]}],"best_for":"E5 mountain and E6 coast with advective fog; not E3 inland desert","limits":"Needs fog frequency and wind; high-wind sites destroy meshes; requires 12+ months of standard fog collector data before investing."},{"name":"Radiative dew condenser on shaded roof facets","principle":"Sky-facing low-emissivity-to-sky coating cools below dew point at night; hydrophilic slippery surface drains condensate","maturity":"EXPERIMENTAL","trl":4,"trl_why":"Measurement standards were only formalised in 2025; household-scale field data remain sparse.","key_numbers":[{"label":"Physical upper bound (50-100 W/m2 net cooling over 10 h night / 2.45 MJ/kg)","value":"0.7-1.5","unit":"L/m2/night","basis":"calculated","sources":["src-beysens-2025"]}],"best_for":"Bonus collection on roofs already built (coastal, steppe); never a primary source","limits":"Realistic yields are a fraction of the bound; wind and cloud kill it; dust fouls surfaces."},{"name":"Shallow well / spring with screening","principle":"Pump lift plus pre-treatment chosen after a lab panel","maturity":"COMMERCIAL","trl":9,"trl_why":"Standard practice.","key_numbers":[{"label":"Ideal pumping energy","value":0.0027,"unit":"kWh per m3 per m lift","basis":"calculated","sources":[]}],"best_for":"E2 forest, E7 steppe, E5 mountain","limits":"Permits and water rights; geogenic contaminants; not available on rooftops or floating sites."}]},{"id":"WATER-S2","name":"Atmospheric water harvesting (AWH) for sites with no liquid water","function":"Make drinking and make-up water from air when no rain, fog, well or saline water is available.","how_it_works":"Two physics families. Dewing (refrigerant AWG) cools air below its dew point; the latent heat of about 0.68 kWh per litre must be pumped by a compressor, and at low RH most of the cooling goes into sensible heat of dry air, so litres per kWh collapse below about 30-40% RH. Sorption AWH loads a sorbent (MOF-303, MOF-801, silica gel, LiCl or CaCl2 hydrogels) at night when RH is highest, then desorbs with solar or waste heat into a closed vapour loop whose dew point is far above ambient, so the condenser can be plain ambient air. The governing ratio is p_sat(T_condenser)/p_sat(T_bed) versus the sorbent's uptake step; MOF-303's step near 10-20% RH makes it work in deserts. Multicycle operation (many short cycles per day) beats capacity: Hanikel 2019 showed sorption kinetics, not equilibrium capacity, sets litres per kg per day.","options":[{"name":"Passive single-cycle MOF harvester (Yaghi / Atoco class)","principle":"Night adsorption, sunlight-driven morning desorption, natural-convection condenser, no electricity","maturity":"EXPERIMENTAL","trl":5,"trl_why":"Desert-validated prototypes (Arizona 2017-18, Death Valley 2023); Atoco containerised units announced for 2026, unproven in fleet.","key_numbers":[{"label":"MOF-801 desert yield, one day-night cycle","value":0.1,"unit":"L/kg MOF/day","basis":"measured","sources":["src-fathieh-2018"]},{"label":"Death Valley 2023 hand-held harvester","value":"up to 0.285","unit":"L/kg MOF/day","basis":"measured","sources":["src-uc-deathvalley","src-song-2023-nw"]},{"label":"Fraction of captured vapour released as drinking water","value":"85-90","unit":"%","basis":"measured","sources":["src-uc-deathvalley"]},{"label":"MOF-801 Tempe device thermal efficiency","value":14,"unit":"% solar-to-water","basis":"measured","sources":["src-kim-2018"]}],"best_for":"E3 desert and E8 lunar-analogue demonstrations; small drinking residuals","limits":"Needs 100s of kg of sorbent for a household; MOF cost and long-term cycling stability under dust are unproven."},{"name":"Active multicycle sorption with PV or battery heat","principle":"Fans and electric or PV-T heat run many short cycles per day; adaptive control of cycle timing to weather","maturity":"PILOT","trl":6,"trl_why":"Multiple outdoor prototypes with energy data; no long-term product fleet.","key_numbers":[{"label":"MOF-303 Mojave field yield, rapid cycling","value":0.7,"unit":"L/kg MOF/day","basis":"measured","sources":["src-hanikel-2019"]},{"label":"Adaptive MOF device yield (17-32% RH)","value":3.5,"unit":"L/kg MOF/day","basis":"measured","sources":["src-almassad-2022"]},{"label":"Adaptive MOF device energy","value":"1.67-5.25","unit":"kWh/L","basis":"measured","sources":["src-almassad-2022"]},{"label":"Silica gel OHW system efficiency","value":"0.46-1.5","unit":"L/kWh","basis":"measured","sources":["src-li-2024-ohw"]},{"label":"Water from 1 m2 PV driving sorption AWH (Shanghai, year-round)","value":"0.66-2","unit":"L/day","basis":"measured","sources":["src-li-2024-ohw"]},{"label":"Global design target from Lord et al. (1 m2 device, 30-90% RH)","value":"0.2-2.5","unit":"L/kWh","basis":"target","sources":["src-lord-2021"]}],"best_for":"E3 desert, E4 polar camps with spare heat, E1 rooftop as resilience","limits":"Litres per kWh is 100-1000x worse than desalinating any saline source; only rational for residual demand."},{"name":"Waste-heat desorption (Uravu / AirJoule / PoliTo closed regeneration loop)","principle":"Low-grade 35-80 C heat from chillers, heat pumps, servers or solar thermal regenerates a desiccant in a closed, near-isothermal air loop; condensation at ambient","maturity":"PILOT","trl":6,"trl_why":"AirJoule Prime unveiled 2026 and described as still being refined, with two more units being built for demonstration or customer trials; Uravu markets a data-centre product without independent field data; household integration unproven.","key_numbers":[{"label":"PoliTo closed-cycle heat demand","value":2.7,"unit":"kWh_th/L","basis":"claimed","sources":["src-pat-polito"]},{"label":"PoliTo open-cycle heat demand","value":4.7,"unit":"kWh_th/L","basis":"claimed","sources":["src-pat-polito"]},{"label":"PoliTo regeneration temperature","value":"45 (example) / 50-80 (heat source range)","unit":"C","basis":"claimed","sources":["src-pat-polito"]},{"label":"Uravu output per MW (heat vs IT load unspecified)","value":30000,"unit":"L/MW/day","basis":"claimed","sources":["src-uravu-site"]},{"label":"AirJoule Prime unit output","value":"up to 2000","unit":"L/day","basis":"claimed","sources":["src-technically-airjoule"]}],"best_for":"Any ORIJO site with a heat pump, cold store or farm LED heat to dump","limits":"Heat must be genuinely free; electrical fan load (about 400 W in the PoliTo example) remains."},{"name":"Refrigerant dewing AWG (Watergen, Genaq, Aquaria)","principle":"Vapour-compression cooling below dew point, filtration, mineralisation","maturity":"COMMERCIAL","trl":9,"trl_why":"Sold for decades; performance strongly climate dependent; vendors rarely publish kWh/L.","key_numbers":[{"label":"Watergen GENNY Plus output","value":20,"unit":"L/day","basis":"claimed","sources":["src-watergen-site"]},{"label":"Aquaria Hydropack output","value":"~132","unit":"US gal/day","basis":"claimed","sources":["src-aquaria-site"]},{"label":"Latent heat floor before compressor COP","value":0.68,"unit":"kWh/L","basis":"calculated","sources":[]}],"best_for":"Humid tropics and coasts (E6) where RH > 60%","limits":"Vendors (Watergen, Genaq, Aquaria pages read) give no kWh/L; yield collapses in dry air; refrigerant and filter maintenance."},{"name":"Solar-PV hydropanel (SOURCE Global)","principle":"PV-powered fan and desiccant, solar-heated regeneration, on-panel reservoir with mineralisation (patent US11160223B2 describes a rotating desiccant wheel)","maturity":"COMMERCIAL","trl":8,"trl_why":"Thousands shipped, but documented field reliability and support failures.","key_numbers":[{"label":"Field output per panel (Allensworth)","value":"about 1","unit":"US gal/panel/day","basis":"reported","sources":["src-sjv-allensworth"]}],"best_for":"Drinking-water top-up only","limits":"About 4 L per panel per day versus 100+ L/person/day domestic need; Allensworth panels broke and went unserviced."}]},{"id":"WATER-S3","name":"Desalination and saline-water polishing","function":"Turn seawater, brackish groundwater or the loop's own RO reject into fresh water at the lowest kWh per m3.","how_it_works":"Reverse osmosis pushes water through a polyamide membrane against osmotic pressure; the thermodynamic minimum for seawater is about 1 kWh/m3 and real plants use 3-5.5 kWh/m3. Electrodialysis moves ions, not water, through ion-exchange membranes under a DC field, so its energy scales with salt removed and suits brackish water; MIT's direct-drive PV-ED varies current and flow 3-5 times per second to follow sunlight with no battery. Interfacial solar evaporation localises heat in a thin absorber; single-stage evaporation at 1 sun is capped near 1.5 kg/m2/h by latent heat, and the real bottleneck is condensing and collecting the vapour, which multistage stills address by reusing latent heat. Membrane distillation passes vapour through a hydrophobic membrane driven by a temperature difference; ISS's Brine Processor uses this principle on urine brine.","options":[{"name":"Small PV-RO (seawater or brackish)","principle":"Pressure-driven membrane separation with energy recovery device","maturity":"COMMERCIAL","trl":9,"trl_why":"Off-the-shelf watermakers from 10 L/h upward.","key_numbers":[{"label":"Seawater RO electrical energy","value":"3-5.5","unit":"kWh/m3","basis":"reported","sources":["src-wiki-desal"]},{"label":"Theoretical minimum, seawater","value":"about 1","unit":"kWh/m3","basis":"reported","sources":["src-wiki-desal","src-elimelech-2011"]}],"best_for":"E6 coast / floating","limits":"Brine disposal, membrane fouling, antiscalant and pre-filter consumables; small units have no energy recovery."},{"name":"Direct-drive PV electrodialysis (MIT)","principle":"Flow-commanded current control matches ED load to instantaneous PV power","maturity":"PILOT","trl":6,"trl_why":"Six-month community-scale field test at Alamogordo; not yet a product.","key_numbers":[{"label":"Output","value":"up to 5000","unit":"L/day","basis":"measured","sources":["src-mit-pved-2024"]},{"label":"PV electricity used directly for desalination","value":94,"unit":"% (average, over)","basis":"measured","sources":["src-mit-pved-2024"]},{"label":"Battery capacity reduction vs conventional","value":"almost 100","unit":"%","basis":"claimed","sources":["src-mit-pved-2024"]}],"best_for":"E3/E7 sites with brackish wells; hotel or village scale","limits":"Brackish only; scaled for ~3,000 people, needs miniaturisation for one home."},{"name":"Solar interfacial / membrane distillation still (SolarDew-class)","principle":"Photothermal absorber or membrane distillation, passive condensation","maturity":"EXPERIMENTAL","trl":5,"trl_why":"Lab rates high; meter-scale outdoor production rates are a fraction of indoor numbers; SolarDew is crowdfunding.","key_numbers":[{"label":"Outdoor seawater evaporation rate, laser-processed wood evaporator","value":1.95,"unit":"kg/m2/h","basis":"measured","sources":["src-chu-2025-langmuir"]}],"best_for":"Emergency drinking water, RO-reject concentration, salt crops","limits":"Evaporation is not collection; salt crusting; area-hungry."}]},{"id":"WATER-S4","name":"Treatment barriers and disinfection","function":"Stack independent barriers so that any single failure does not deliver unsafe water.","how_it_works":"Biology first: an aerobic bioreactor (MBR, MBBR) converts biodegradable COD and surfactants to CO2 and biomass, which is what membranes and UV need to stay unfouled. Membranes then remove particles and bacteria by size (UF 0.01-0.1 um) and RO removes dissolved salts and most organics. UV-C at about 254-280 nm damages nucleic acids; LEDs switch instantly and allow wavelength choice, but dose depends on UV transmittance, so turbidity upstream matters. A residual disinfectant (free chlorine from on-site electrolysis) is required because treated water can regrow pathogens in storage, as Eawag found in the Autarky toilet. Granular activated carbon polishes micropollutants and pharmaceuticals.","options":[{"name":"Membrane bioreactor for greywater","principle":"Aerobic biology + submerged UF membrane","maturity":"COMMERCIAL","trl":9,"trl_why":"Single-house and building MBRs documented since 2000s.","key_numbers":[{"label":"COD removal, single-house SMBR (Crete)","value":87,"unit":"%","basis":"measured","sources":["src-fountoulakis-2016"]},{"label":"TSS influent to effluent","value":"95 to 8","unit":"mg/L","basis":"measured","sources":["src-fountoulakis-2016"]}],"best_for":"All environments with a heated wet room","limits":"Membrane fouling and biology upsets after holidays or detergent shocks."},{"name":"UV-C LED flow-through reactor","principle":"Germicidal UV with instant on/off and wavelength selection","maturity":"COMMERCIAL","trl":9,"trl_why":"Point-of-use products widely sold; inconsistency in published dose data noted by review.","key_numbers":[{"label":"Status of dose data","value":"inconsistent across studies","unit":"qualitative","basis":"reported","sources":["src-song-2016-uvled"]}],"best_for":"Final barrier on potable tap and on tank recirculation","limits":"No residual; turbidity shields pathogens; LED output decays over life and must be monitored by a UV sensor."},{"name":"Constructed wetland (vertical / recirculating)","principle":"Plant-root and biofilm treatment in gravel beds","maturity":"COMMERCIAL","trl":9,"trl_why":"Widely built; meets chemical but not microbiological reuse standards alone.","key_numbers":[{"label":"Microbiological standards reliably met without disinfection","value":"no","unit":"qualitative","basis":"reported","sources":["src-arden-ma-2018"]}],"best_for":"E7 steppe, E2 forest, farm sites with land","limits":"Land area, freezing, needs UV or chlorine after it."},{"name":"Electrochlorination residual + GAC","principle":"Electrolysis of chloride makes hypochlorite in situ; activated carbon adsorbs organics","maturity":"COMMERCIAL","trl":9,"trl_why":"Standard pool and remote-site practice; tested on Autarky toilet.","key_numbers":[],"best_for":"Storage tanks in warm climates","limits":"By-products (chlorate, THMs) must be monitored; GAC can itself grow biofilm."}]},{"id":"WATER-S5","name":"Reuse loops by stream (grey, yellow, brown, condensate)","function":"Separate streams at source so each is treated with the cheapest sufficient process and its nutrients go to the farm.","how_it_works":"Urine is about 1% of household wastewater volume but carries most excreted N and P, so diverting it shrinks nutrient loads on the grey loop and turns them into fertiliser. Urine stabilised by nitrification (MBBR, pH held by feed or electrochemically) converts ammonia to nitrate so it no longer smells or volatilises; activated carbon removes pharmaceuticals; distillation concentrates it into Aurin-type fertiliser. Vacuum toilets use 0.5-1.2 L per flush and deliver concentrated blackwater that can be digested anaerobically, although high free ammonia lowers methane yield. Greywater, the largest volume, gets biology plus membranes plus RO for potable quality (WOTA) or biology plus UV for toilet and laundry (Hydraloop). The ISS shows the end state: all streams including humidity condensate and urine are recovered at 98%.","options":[{"name":"Household wastewater regeneration appliance (WOTA Unit; potable status disputed)","principle":"Biology, membranes, RO and disinfection under autonomous control, rainwater make-up","maturity":"PILOT","trl":6,"trl_why":"Passed TRL 6 in 2025 per press; household trials in several Japanese municipalities from January 2026. WOTA's site says the Unit meets WHO drinking-water guidelines, but the February 2026 press report says households still need external drinking water until a rainwater purification module is finished: treat potable reuse as unproven.","key_numbers":[{"label":"Domestic wastewater regenerated","value":"97 (up to)","unit":"%","basis":"claimed","sources":["src-wota-site","src-dailygalaxy-wota"]},{"label":"WOTA BOX shower water recirculated","value":"about 98","unit":"%","basis":"claimed","sources":["src-wota-site"]}],"best_for":"All ORIJO homes and hotels (MIZU-1 partner)","limits":"Drinking water still comes from external sources in the current product; vendor numbers."},{"name":"Greywater to non-potable (Hydraloop)","principle":"Six biological/physical stages without membranes or filters","maturity":"COMMERCIAL","trl":9,"trl_why":"Shipped product with NSF/ANSI 350R and other certifications.","key_numbers":[{"label":"Greywater recycled","value":95,"unit":"% (up to)","basis":"claimed","sources":["src-hydraloop-site"]},{"label":"Freshwater demand cut","value":45,"unit":"% (up to)","basis":"claimed","sources":["src-hydraloop-site"]},{"label":"H600 capacity","value":720,"unit":"L/day (up to)","basis":"claimed","sources":["src-hydraloop-site"]}],"best_for":"E1 rooftop and hotels on mains water","limits":"Non-potable only; less useful where all water is scarce."},{"name":"Urine nitrification + activated carbon + distillation (VUNA / Aurin)","principle":"Biological nitrification stabilises N; GAC removes drugs; distillation concentrates","maturity":"COMMERCIAL","trl":8,"trl_why":"Licensed fertiliser product in Switzerland (temporary 2015, full 2018) from a small plant.","key_numbers":[{"label":"Distillation primary energy","value":71,"unit":"W/capita","basis":"measured","sources":["src-fumasoli-2016"]},{"label":"Nitrification primary energy","value":13,"unit":"W/capita","basis":"measured","sources":["src-fumasoli-2016"]},{"label":"Max nitrification rate (MBBR pilot)","value":930,"unit":"mg N/L/day","basis":"measured","sources":["src-fumasoli-2016"]}],"best_for":"KAWAYA-U; all sites with a HATA farm","limits":"Distillation energy dominates; nitrite accumulation and acid-tolerant AOB are failure modes needing supervision."},{"name":"Vacuum toilet + anaerobic blackwater (Sneek / DeSaH)","principle":"Concentrated blackwater digested in UASB for biogas, struvite P recovery","maturity":"PILOT","trl":7,"trl_why":"32-house full-scale demonstration; not a single-home product.","key_numbers":[{"label":"Vacuum toilet water per flush","value":"0.5-1.2","unit":"L","basis":"measured","sources":["src-gao-2019"]},{"label":"N preserved from vacuum blackwater (32 houses)","value":7.6,"unit":"g N/person/day","basis":"measured","sources":["src-zeeman-2011"]}],"best_for":"Hotel 6-key and clusters of 10+ homes","limits":"Vacuum station power and noise; ammonia inhibits digestion; scale economies."},{"name":"Spacecraft-grade total loop (ISS UPA + WPA + BPA)","principle":"Vapour-compression distillation of urine, multifiltration + catalytic oxidation + iodine for all water, membrane-distillation brine bladder","maturity":"PILOT","trl":9,"trl_why":"TRL 9 as flight hardware (UPA/WPA since 2008, BPA since 2021); there is no terrestrial or commercial version, so maturity for an ORIJO home is PILOT at best.","key_numbers":[{"label":"Total water recovery with BPA","value":98,"unit":"%","basis":"measured","sources":["src-nasa-98","src-ntrs-iss-2026"]},{"label":"UPA recovery from US pretreated urine","value":87,"unit":"%","basis":"measured","sources":["src-ntrs-iss-2026"]}],"best_for":"Design reference for E8 lunar and fully closed units","limits":"Expendables, pretreat chemicals, frequent pump failures; extraordinary maintenance effort."}]},{"id":"WATER-S6","name":"Autonomous monitoring and safety interlock","function":"Decide, every few minutes, whether each tank may be released to a tap, the farm or the grey loop, without a lab.","how_it_works":"Indicator bacteria cannot yet be measured online cheaply, so control uses proxies: free chlorine, ORP, conductivity, turbidity, UV transmittance, TOC and pressure-decay membrane integrity tests. Reynaert et al. showed that a logistic-regression model using only free chlorine and ORP (plus their slopes) predicted 'unsafe' microbial quality in an MBR-chlorination system with the false-positive rate fixed at or below 2%, and its errors were mostly early alarms. Optical flow-cytometry-style bacteria counters give 10-minute resolution total counts. A fail-safe valve topology means water defaults to the grey loop and only a positive 'safe' verdict opens the potable path.","options":[{"name":"Proxy-sensor soft sensor (free Cl + ORP + slopes)","principle":"Supervised classifier with a fixed false-positive ceiling","maturity":"EXPERIMENTAL","trl":5,"trl_why":"Validated on lab-induced disruptions in pilot MBRs; no certified product.","key_numbers":[{"label":"False-positive rate ceiling enforced","value":2,"unit":"% max","basis":"measured","sources":["src-reynaert-2023"]},{"label":"Sensors needed for best TPR","value":"1-2","unit":"sensors","basis":"measured","sources":["src-reynaert-2023"]}],"best_for":"All MIZU loops","limits":"Trained on one process train; must be retrained per design and checked against grab samples."},{"name":"Online optical bacteria counter","principle":"3D image recognition of particles, classification bacteria vs abiotic","maturity":"PILOT","trl":7,"trl_why":"Field applications reported; counts total bacteria, not E. coli.","key_numbers":[{"label":"Time resolution","value":10,"unit":"min","basis":"measured","sources":["src-hojris-2016"]},{"label":"Image parameters used","value":59,"unit":"parameters","basis":"measured","sources":["src-hojris-2016"]}],"best_for":"Hotel and farm-scale loops where cost is shared","limits":"Cost; not pathogen specific; fouling of the flow cell."},{"name":"Membrane integrity + conductivity + UVT hard interlocks","principle":"Pressure-decay test on UF/RO, conductivity rejection ratio, UV sensor on LED reactor","maturity":"COMMERCIAL","trl":9,"trl_why":"Standard in potable reuse plants.","key_numbers":[],"best_for":"All","limits":"Proxy only; does not see breakthrough of viruses through intact membranes."}]},{"id":"WATER-S7","name":"Storage, distribution, irrigation and residuals","function":"Hold water safely, move it by gravity where possible, feed the farm, and export brine and nutrients as products.","how_it_works":"A tall tank (KRES-7 mast, about 2,000 L) gives gravity pressure (0.1 bar per metre) and buffer for multi-day harvest variability. Storage is the regrowth risk point, so tanks get recirculation through UV and a chlorine residual, and are dark and cool. Irrigation draws nitrified urine and greywater effluent as nutrient solution, the farm's transpiration is recaptured by the dehumidifier as near-distilled condensate (the SOURCE patent closes this loop explicitly). RO reject and urine brine are concentrated by membrane distillation and dried, so the only exports are salt cake and fertiliser.","options":[{"name":"Mast gravity tank with recirculating UV","principle":"Elevated storage, timed recirculation through UV-C LED","maturity":"COMMERCIAL","trl":9,"trl_why":"Standard components.","key_numbers":[{"label":"KRES-7 tank volume","value":2000,"unit":"L","basis":"target","sources":["src-anyground-v3"]}],"best_for":"All","limits":"Freeze protection in E4/E5; structural load on the mast."},{"name":"Brine bladder membrane distillation (ISS BPA analogue)","principle":"Membrane bladder passes vapour to heated forced air; humidity recovered by the condensate loop","maturity":"PILOT","trl":7,"trl_why":"Operating in orbit since 2021 as a technology demonstration; no terrestrial product.","key_numbers":[{"label":"Water returned from brine since Feb 2024","value":"about 780 of 946","unit":"L","basis":"measured","sources":["src-ntrs-iss-2026"]},{"label":"Dewatering cycles since 2021","value":81,"unit":"cycles","basis":"measured","sources":["src-ntrs-iss-2026"]}],"best_for":"Pushing ORIJO net recovery from 90-95% toward 98%","limits":"Bladders are consumables; heat demand; scaling with organics."},{"name":"Farm transpiration recapture","principle":"Dehumidifier or desiccant unit on the grow chamber returns transpired water to the loop","maturity":"PILOT","trl":6,"trl_why":"Patented by Source Global for container farms; CEA dehumidifiers common, closed-loop operation rare.","key_numbers":[],"best_for":"HATA-4, BYOBU-G, YOSHI-6G greenhouse","limits":"Condensate can carry Legionella and plant-derived organics; route to the grey loop, not straight to the tap."}]}],"projects":[{"id":"P-ISS-WRS","name":"ISS Water Recovery System (WPA, UPA, BPA)","org":"NASA / Boeing / Paragon / Collins","country":"International (US segment)","year_or_period":"2008-present","what":"Closed water loop recovering humidity condensate and urine for drinking on orbit.","status":"active","outcome_or_lesson":"98% total recovery once the Brine Processor was added (93-94% before); but 2024-26 report lists repeated purge pump failures, a toilet in stand-down from a failed dose pump, a Sabatier offline since 2017, and about 300 L of pretreated urine stored during UPA downtime (later all processed, none disposed). The loop works because a ground team and spares exist.","sources":["src-nasa-98","src-ntrs-iss-2026","src-yt-iss-hadfield"]},{"id":"P-BPA","name":"Brine Processor Assembly","org":"Paragon Space Development / NASA","country":"USA","year_or_period":"2021-present","what":"Membrane-distillation bladder drying urine brine with warm forced air.","status":"active","outcome_or_lesson":"About 780 L returned from 946 L brine since Feb 2024; a household analogue could take RO reject and urine brine to dryness.","sources":["src-ntrs-iss-2026"]},{"id":"P-MELISSA","name":"MELiSSA closed ecological loop","org":"ESA / UAB Barcelona pilot plant","country":"EU / Spain","year_or_period":"1989-present","what":"Five-compartment bioregenerative loop including a nitrifying compartment fed with urine-derived streams.","status":"research","outcome_or_lesson":"A 2026 COSPAR abstract (title only; abstract page could not be retrieved in verification) reports work toward complete gas closure and liquid integration with food production; still a research pilot after 35+ years, which shows how hard biological closure is.","sources":["src-melissa-esa","src-melissa-2026"]},{"id":"P-WOTA","name":"WOTA Unit / WOTA BOX / WOSH","org":"WOTA Corp.","country":"Japan","year_or_period":"2019-present","what":"Autonomous greywater regeneration for showers (BOX), handwashing (WOSH) and whole homes (Unit).","status":"pilot","outcome_or_lesson":"BOX deployed after the 2024 Noto earthquake; Unit claims 97% regeneration and passed TRL 6 in 2025, with household trials from January 2026. Japan's June 2025 Cabinet policy backs decentralised water. Drinking water: conflicting sources - the WOTA site says the Unit meets WHO drinking-water guidelines, while Feb 2026 press says a rainwater purification module for drinking water is still in development. The current WOTA English site does not mention the Noto deployment (claim rests on other sources).","sources":["src-wota-site","src-dailygalaxy-wota","src-yt-wota-unit","src-yt-wota-box"]},{"id":"P-HYDRALOOP","name":"Hydraloop H300/H600","org":"Hydraloop Systems","country":"Netherlands","year_or_period":"2015-present","what":"Membrane-free greywater recycler for toilets, laundry, irrigation.","status":"shipped","outcome_or_lesson":"NSF/ANSI 350R certified; up to 95% of greywater recycled and up to 45% cut in mains demand. Proves a certified appliance path; non-potable only.","sources":["src-hydraloop-site","src-hydraloop-brochure"]},{"id":"P-SOURCE","name":"SOURCE hydropanels (formerly Zero Mass Water)","org":"Source Global PBC","country":"USA","year_or_period":"2014-present","what":"Solar-powered desiccant panels producing drinking water from air.","status":"shipped (2026 status unverified)","outcome_or_lesson":"Raised capital from Gates and BlackRock investors (2022, headline). In Allensworth, CA, many of about 42 panels broke and went unserviced, each giving about a gallon per day. Lesson: service network and honest yield beat product novelty. Allensworth report dated 13 March 2024; town need about 1.5 million gal/month; company said it would inspect panels. Company status in 2026 not re-verified (site rate-limited, search budget exhausted).","sources":["src-sjv-allensworth","src-cnbc-source-2022","src-pat-source","src-yt-source-dubai"]},{"id":"P-ATOCO","name":"Atoco MOF water harvesters","org":"Atoco (founded by Omar Yaghi)","country":"USA","year_or_period":"2020s-present","what":"20-ft containerised MOF harvesters; also greenhouse humidity extraction.","status":"pilot","outcome_or_lesson":"Claims 2,000-4,000 L/day on grid and up to 1,000 L/day off grid; commercial rollout aimed 'within the next year' as of January 2026. Yaghi shared the 2025 Nobel Prize in Chemistry. Treat outputs as claims until independent field data.","sources":["src-agnav-atoco"]},{"id":"P-YAGHI-DV","name":"Death Valley hand-held MOF harvester","org":"UC Berkeley (Yaghi group)","country":"USA","year_or_period":"2023","what":"Passive MOF harvester tested in Death Valley in ambient sunlight.","status":"research","outcome_or_lesson":"285 g water per kg MOF per day, 85-90% of captured vapour delivered: honest scale is cups, not tanks.","sources":["src-uc-deathvalley","src-song-2023-nw","src-yt-yaghi-desert"]},{"id":"P-MIT-MOF801","name":"MOF-801 desert devices (Tempe, Arizona)","org":"MIT (Wang) / UC Berkeley (Yaghi)","country":"USA","year_or_period":"2017-2018","what":"First MOF harvesters run in a real desert with sunlight only.","status":"research","outcome_or_lesson":"About 0.1-0.25 L/kg MOF per day-night cycle at 10-40% RH with about 14% thermal efficiency; established the physics and the low per-kg yield.","sources":["src-kim-2017","src-kim-2018","src-fathieh-2018"]},{"id":"P-ADAPTIVE-MOF","name":"Adaptive self-optimising MOF device","org":"Almassad et al. (Jordan / Saudi Arabia team)","country":"Jordan","year_or_period":"2022","what":"Controller adapts adsorption and desorption timing to weather.","status":"research","outcome_or_lesson":"3.5 L/kg/day at 17-32% RH with 1.67-5.25 kWh/L in a desert, arid climate; the +169% is relative to the best previously reported active device (MOF-303, 0.7-1.3 L/kg/day, a different device), not a controlled A/B test of control software alone. Still the strongest evidence that weather-adaptive cycle timing matters.","sources":["src-almassad-2022"]},{"id":"P-AIRJOULE","name":"AirJoule Prime","org":"AirJoule Technologies (JV with GE Vernova)","country":"USA","year_or_period":"2024-present","what":"Sorbent water-from-air units using waste heat from chillers and heat pumps.","status":"pilot","outcome_or_lesson":"Unveiled 2026 with up to 2,000 L/day; energy per litre not disclosed in the article read.","sources":["src-technically-airjoule","src-yt-airjoule"]},{"id":"P-URAVU","name":"Uravu Labs","org":"Uravu Labs","country":"India","year_or_period":"2019-present","what":"Liquid salt absorbent regenerated by 35-60 C waste heat; now positioned for data centres.","status":"active","outcome_or_lesson":"Pivoted from bottled water to data-centre cooling by-product (Clausius, regenerated by 35-60 C waste heat); claims up to 30,000 L per MW per day (MW basis unspecified). Seed of USD 2.3 M (2023, headline); further funding from Enrission India Capital reported July 2025 (headline only, amount not verified).","sources":["src-uravu-site","src-entrackr-uravu","src-bwdisrupt-uravu-2025"]},{"id":"P-WATERGEN","name":"Watergen GENNY / GEN-M / GEN-L","org":"Watergen","country":"Israel","year_or_period":"2009-present","what":"Refrigerant-based atmospheric water generators from countertop to industrial.","status":"shipped","outcome_or_lesson":"GENNY Plus 20 L/day; no kWh/L published on the site read, a recurring transparency gap across the AWG industry.","sources":["src-watergen-site"]},{"id":"P-GENAQ","name":"GENAQ Stratus / Nimbus / Cumulus","org":"GENAQ","country":"Spain","year_or_period":"2010s-present","what":"AWGs for emergencies and industry, claimed to work above 50 C and below 20% RH.","status":"shipped","outcome_or_lesson":"No litres or kWh figures on the site; claims unverifiable.","sources":["src-genaq-site"]},{"id":"P-AQUARIA","name":"Aquaria Hydropack","org":"Aquaria","country":"USA","year_or_period":"2020s-present","what":"Residential condensation AWG sized at 66-264 US gal/day.","status":"shipped","outcome_or_lesson":"Large residential AWG claims; no energy disclosure on the site.","sources":["src-aquaria-site"]},{"id":"P-SOLARDEW","name":"SolarDew","org":"SolarDew","country":"Netherlands","year_or_period":"2010s-present","what":"Solar membrane-distillation purifier for remote households.","status":"pilot","outcome_or_lesson":"Still crowdfunding (Republic Europe) with a target of 1 million people by 2035; no output figures on the site.","sources":["src-solardew-site"]},{"id":"P-MIT-PVED","name":"Direct-drive PV electrodialysis","org":"MIT (Winter lab)","country":"USA","year_or_period":"2024","what":"Battery-free brackish desalination following the sun.","status":"pilot","outcome_or_lesson":"5,000 L/day for six months at Alamogordo using over 94% of PV electricity directly.","sources":["src-mit-pved-2024"]},{"id":"P-VUNA","name":"VUNA / Aurin urine fertiliser","org":"Eawag / Vuna GmbH","country":"Switzerland / South Africa","year_or_period":"2010-present","what":"Urine nitrification, activated carbon and distillation into a licensed fertiliser.","status":"active","outcome_or_lesson":"Licensed by FOAG (temporary 2015, full 2018 per Vuna); eThekwini field work showed social and logistics limits; distillation energy is the cost driver.","sources":["src-eawag-vuna","src-vuna-aurin","src-udert-2012","src-fumasoli-2016"]},{"id":"P-AUTARKY","name":"Blue Diversion / Autarky toilet","org":"Eawag with EOOS","country":"Switzerland / Uganda","year_or_period":"2011-2018","what":"Urine-diverting toilet recycling wash water through a gravity MBR plus GAC and chlorine/electrolysis.","status":"closed","outcome_or_lesson":"Users in Kampala liked it, but treated water regrew E. coli, Pseudomonas and Salmonella in storage without a residual; cost and space were concerns. Lesson: residual disinfection and business model are not optional.","sources":["src-nguyen-2017","src-tobias-2017"]},{"id":"P-SNEEK","name":"Vacuum blackwater + anaerobic treatment demo (Sneek, NL)","org":"Wageningen / DeSaH / STOWA","country":"Netherlands","year_or_period":"2006-2011","what":"32 houses with vacuum toilets feeding UASB digestion and struvite recovery.","status":"pilot","outcome_or_lesson":"Preserved 7.6 g N and 0.63 g P per person per day (69% and 48%); proves cluster-scale source separation.","sources":["src-zeeman-2011","src-zeeman-2008"]},{"id":"P-NEST-REUSE","name":"On-site reuse with online sensors (NEST Water Hub)","org":"Eawag / ETH Zurich","country":"Switzerland","year_or_period":"2019-2024","what":"MBR + chlorination reuse loops with ML microbial-quality prediction.","status":"research","outcome_or_lesson":"Two cheap sensors (free chlorine, ORP) gave safe/unsafe classification at FPR <= 2%.","sources":["src-reynaert-2023"]},{"id":"P-POLITO","name":"Low-temperature heat AWH cycle","org":"Politecnico di Torino","country":"Italy","year_or_period":"2017-2023 (patent)","what":"Paired enthalpy exchangers with closed near-isothermal regeneration loop.","status":"research","outcome_or_lesson":"Claims 2.7 kWh_th/L closed vs 4.7 open: closing the regeneration air loop is a cheap design win.","sources":["src-pat-polito"]},{"id":"P-FOG","name":"Operational fog collection projects (Chile, Peru, Morocco, Oman, South Africa)","org":"Various (FogQuest, Dar Si Hmad and others, reviewed by Klemm et al.)","country":"Multiple","year_or_period":"1980s-present","what":"Large passive mesh collectors for villages and reforestation.","status":"active","outcome_or_lesson":"Typical 3-10 L/m2/day yearly average; success hinges on site selection, community ownership and maintenance.","sources":["src-klemm-2012"]},{"id":"P-SHANGHAI-OHW","name":"Optimal Harvesting Window silica-gel AWH","org":"Shanghai Jiao Tong University (Ge, Wang)","country":"China","year_or_period":"2024","what":"Thermodynamically tuned silica-gel AWH with PV drive.","status":"research","outcome_or_lesson":"0.46-1.5 L/kWh; a 1 m2 PV panel makes 0.66-2 L/day: cheap sorbent plus control beats exotic materials.","sources":["src-li-2024-ohw"]},{"id":"P-P2W","name":"Power-to-water battery","org":"Shanghai Jiao Tong University (Wu group)","country":"China","year_or_period":"2023-2025","what":"Stores surplus electricity as MgO-based high-temperature heat, discharges it to desorb a liquid sorbent.","status":"research","outcome_or_lesson":"3.06 L/day prototype at 1.13 kWh/kg; turns curtailed PV into water.","sources":["src-lin-2025-p2w"]}],"papers":[{"id":"PA-lord-2021","title":"Global potential for harvesting drinking water from air using solar energy","authors":"Lord J. et al.","year":2021,"venue":"Nature","doi_or_url":"10.1038/s41586-021-03900-w","finding":"A 1 m2 device at 0.2-2.5 L/kWh (30-90% RH) could meet 5 L/person/day for about a billion people.","type":"model"},{"id":"PA-kim-2017","title":"Water harvesting from air with metal-organic frameworks powered by natural sunlight","authors":"Kim H. et al.","year":2017,"venue":"Science","doi_or_url":"10.1126/science.aam8743","finding":"MOF-801 harvest of 2.8 L per kg MOF per day at 20% RH (projected from lab cycle).","type":"experiment"},{"id":"PA-kim-2018","title":"Adsorption-based atmospheric water harvesting device for arid climates","authors":"Kim H. et al.","year":2018,"venue":"Nature Communications","doi_or_url":"10.1038/s41467-018-03162-7","finding":"Air-cooled MOF-801 device at 10-40% RH reached about 14% thermal efficiency and over 0.25 L/kg per daily cycle (predicted).","type":"field-trial"},{"id":"PA-fathieh-2018","title":"Practical water production from desert air","authors":"Fathieh F. et al.","year":2018,"venue":"Science Advances","doi_or_url":"10.1126/sciadv.aat3198","finding":"1.2 kg MOF-801 prototype produced 100 g water/kg/day in the Arizona desert with sunlight only.","type":"field-trial"},{"id":"PA-hanikel-2019","title":"Rapid cycling and exceptional yield in a metal-organic framework water harvester","authors":"Hanikel N. et al.","year":2019,"venue":"ACS Central Science","doi_or_url":"10.1021/acscentsci.9b00745","finding":"MOF-303 multicycle harvester: 1.3 L/kg/day indoors at 32% RH and 0.7 L/kg/day in the Mojave at 10% RH.","type":"field-trial"},{"id":"PA-song-2023","title":"MOF water harvester produces water from Death Valley desert air in ambient sunlight","authors":"Song W. et al. (Yaghi group)","year":2023,"venue":"Nature Water","doi_or_url":"https://www.nature.com/articles/s44221-023-00103-7","finding":"Up to 285 g water per kg MOF per day in Death Valley, releasing 85-90% of captured vapour (via UC press release; paper not read).","type":"field-trial"},{"id":"PA-almassad-2022","title":"Environmentally adaptive MOF-based device enables continuous self-optimizing atmospheric water harvesting","authors":"Almassad H.A. et al.","year":2022,"venue":"Nature Communications","doi_or_url":"10.1038/s41467-022-32642-0","finding":"Adaptive cycle control gave 3.5 L/kg MOF/day at 17-32% RH using 1.67-5.25 kWh/L.","type":"field-trial"},{"id":"PA-li-2024","title":"An atmospheric water harvesting system based on the Optimal Harvesting Window design for worldwide water production","authors":"Li Q. et al.","year":2024,"venue":"Science Bulletin","doi_or_url":"10.1016/j.scib.2024.03.018","finding":"3 kg silica gel produced 5.76-17.64 L/day at 0.46-1.5 L/kWh; 1 m2 PV gives 0.66-2 L/day in Shanghai.","type":"experiment"},{"id":"PA-yang-2024","title":"Enhanced continuous atmospheric water harvesting with scalable hygroscopic gel driven by natural sunlight and wind","authors":"Yang X., Chen Z., Xiang C., Shan H., Wang R.","year":2024,"venue":"Nature Communications","doi_or_url":"10.1038/s41467-024-52137-4","finding":"Solar-concentrated hygroscopic gel device gave 3.5-8.9 L/m2/day outdoors (14.9 indoors).","type":"experiment"},{"id":"PA-lin-2025","title":"Multi-stage power-to-water battery synergizes flexible energy storage and efficient atmospheric water harvesting","authors":"Lin H. et al.","year":2025,"venue":"Nature Communications","doi_or_url":"10.1038/s41467-025-66053-8","finding":"3,060 g/day prototype at 1.13 kWh/kg, with three AWH stages cutting energy by 26%.","type":"experiment"},{"id":"PA-li-2018","title":"Hybrid hydrogel with high water vapor harvesting capacity for deployable solar-driven atmospheric water generator","authors":"Li R. et al.","year":2018,"venue":"Environmental Science & Technology","doi_or_url":"10.1021/acs.est.8b02852","finding":"35 g of salt-hydrogel delivered 20 g water in 2.5 h of outdoor sunlight.","type":"experiment"},{"id":"PA-tashtoush-2024","title":"Solar-off-grid atmospheric water harvesting system: performance analysis in diverse climate conditions","authors":"Tashtoush B., Alshoubaki A.Y.","year":2024,"venue":"Science of the Total Environment","doi_or_url":"10.1016/j.scitotenv.2023.167804","finding":"Modelled 3.25, 2.69 and 1.87 kg/kWh for coastal, typical and desert regions.","type":"model"},{"id":"PA-li-wang-2023","title":"Sorbents, processes and applications beyond water production in sorption-based atmospheric water harvesting","authors":"Li R., Wang P.","year":2023,"venue":"Nature Water","doi_or_url":"https://www.nature.com/articles/s44221-023-00099-0","finding":"Review of sorbent classes and co-applications (cooling, dehumidification, irrigation); numbers not extracted (not read).","type":"review"},{"id":"PA-klemm-2012","title":"Fog as a fresh-water resource: overview and perspectives","authors":"Klemm O. et al.","year":2012,"venue":"Ambio","doi_or_url":"10.1007/s13280-012-0247-8","finding":"Operational fog projects typically yield 3-10 L/m2 mesh/day as yearly averages.","type":"review"},{"id":"PA-udert-2012","title":"Complete nutrient recovery from source-separated urine by nitrification and distillation","authors":"Udert K.M., Waechter M.","year":2012,"venue":"Water Research","doi_or_url":"10.1016/j.watres.2011.11.020","finding":"Nitrification (max 1.8 g N/m2/d) plus distillation recovered all nutrients except under 3% of N; primary energy 4-5x conventional unless RO removes 80% of water first.","type":"experiment"},{"id":"PA-fumasoli-2016","title":"Operating a pilot-scale nitrification/distillation plant for complete nutrient recovery from urine","authors":"Fumasoli A. et al.","year":2016,"venue":"Water Science & Technology","doi_or_url":"10.2166/wst.2015.485","finding":"Distillation needed 71 W/capita primary energy vs 13 W/capita for nitrification.","type":"field-trial"},{"id":"PA-depaepe-2021","title":"Electrochemical in situ pH control enables chemical-free full urine nitrification with concomitant nitrate extraction","authors":"De Paepe J. et al.","year":2021,"venue":"Environmental Science & Technology","doi_or_url":"10.1021/acs.est.1c00041","finding":"An electrochemical cell steered by a pH controller replaced base dosing and enabled full nitrification plus nitrate extraction (space and Earth).","type":"experiment"},{"id":"PA-zeeman-2011","title":"Resource recovery from source separated domestic waste(water) streams; full scale results","authors":"Zeeman G., Kujawa-Roeleveld K.","year":2011,"venue":"Water Science & Technology","doi_or_url":"10.2166/wst.2011.562","finding":"Vacuum blackwater in 32 houses preserved 7.6 g N/p/d (69%); urine theoretically carries 11 g N and 1.0 g P per person per day.","type":"field-trial"},{"id":"PA-zeeman-2008","title":"Anaerobic treatment as a core technology for energy, nutrients and water recovery from source-separated domestic waste(water)","authors":"Zeeman G. et al.","year":2008,"venue":"Water Science & Technology","doi_or_url":"10.2166/wst.2008.101","finding":"New sanitation concept (UASB for black and grey water plus kitchen waste) saves 200 MJ/year vs conventional sanitation (abstract does not state per-person basis), recovers 0.14 kg P/p/year and yields 90 L of potentially reusable water.","type":"pilot-based concept"},{"id":"PA-gao-2019","title":"Performance of anaerobic treatment of blackwater collected from different toilet flushing systems","authors":"Gao M. et al.","year":2019,"venue":"Journal of Hazardous Materials","doi_or_url":"10.1016/j.jhazmat.2018.10.055","finding":"Vacuum toilets use 0.5-1.2 L/flush but their blackwater gave 34% BMP vs 48% for 5-9 L flush toilets due to free ammonia.","type":"experiment"},{"id":"PA-li-2009","title":"Review of the technological approaches for grey water treatment and reuses","authors":"Li F., Wichmann K., Otterpohl R.","year":2009,"venue":"Science of the Total Environment","doi_or_url":"10.1016/j.scitotenv.2009.02.004","finding":"Aerobic biology + filtration + disinfection is the most economical greywater recycling train; physical processes alone are insufficient.","type":"review"},{"id":"PA-fountoulakis-2016","title":"Single house on-site grey water treatment using a submerged membrane bioreactor for toilet flushing","authors":"Fountoulakis M.S. et al.","year":2016,"venue":"Science of the Total Environment","doi_or_url":"10.1016/j.scitotenv.2016.02.057","finding":"Single-house SMBR removed 87% COD and cut TSS from 95 to 8 mg/L.","type":"field-trial"},{"id":"PA-arden-2018","title":"Constructed wetlands for greywater recycle and reuse: a review","authors":"Arden S., Ma X.","year":2018,"venue":"Science of the Total Environment","doi_or_url":"10.1016/j.scitotenv.2018.02.218","finding":"Wetlands meet chemical/physical reuse standards but not microbiological ones without UV or chlorine.","type":"review"},{"id":"PA-reynaert-2023","title":"Predicting microbial water quality in on-site water reuse systems with online sensors","authors":"Reynaert E. et al.","year":2023,"venue":"Water Research","doi_or_url":"10.1016/j.watres.2023.120075","finding":"Logistic regression on free chlorine and ORP classified safe/unsafe reuse water with FPR fixed at <= 2%.","type":"experiment"},{"id":"PA-hojris-2016","title":"A novel, optical, on-line bacteria sensor for monitoring drinking water quality","authors":"Hojris B. et al.","year":2016,"venue":"Scientific Reports","doi_or_url":"10.1038/srep23935","finding":"Image-recognition bacteria counter with 10-minute resolution using 59 image parameters.","type":"experiment"},{"id":"PA-song-2016","title":"Application of ultraviolet light-emitting diodes (UV-LEDs) for water disinfection: a review","authors":"Song K., Mohseni M., Taghipour F.","year":2016,"venue":"Water Research","doi_or_url":"10.1016/j.watres.2016.03.003","finding":"UV-LED inactivation data are inconsistent across studies; a standard dose protocol is needed.","type":"review"},{"id":"PA-nguyen-2017","title":"Controlling bacterial pathogens in water for reuse: treatment technologies for water recirculation in the Blue Diversion Autarky Toilet","authors":"Nguyen M.T. et al.","year":2017,"venue":"Frontiers in Environmental Science","doi_or_url":"10.3389/fenvs.2017.00090","finding":"After MBR treatment, E. coli, P. aeruginosa and S. typhimurium could regrow in storage absent competition or residual disinfectant.","type":"experiment"},{"id":"PA-tobias-2017","title":"Early testing of new sanitation technology for urban slums: the case of the Blue Diversion Toilet","authors":"Tobias R. et al.","year":2017,"venue":"Science of the Total Environment","doi_or_url":"10.1016/j.scitotenv.2016.10.057","finding":"Acceptance study with 22 regular users, 308 one-time users and 1,538 surveyed in Kampala (2013).","type":"field-trial"},{"id":"PA-iss-2026","title":"Status of ISS Water Management and Recovery (ICES-2026-425)","authors":"Williamson J., Wilson J.P., Luong H., Chen L.","year":2026,"venue":"55th International Conference on Environmental Systems","doi_or_url":"https://ntrs.nasa.gov/citations/20260004140","finding":"WPA produced about 17,900 L in Feb 2024-Feb 2026; UPA recovers 87% of US urine (target 90%); total 98+% with BPA.","type":"field-trial"},{"id":"PA-elimelech-2011","title":"The future of seawater desalination: energy, technology, and the environment","authors":"Elimelech M., Phillip W.A.","year":2011,"venue":"Science","doi_or_url":"10.1126/science.1200488","finding":"Seawater desalination remains more energy-intensive than fresh-water treatment; reviews limits of energy reduction (numbers not in abstract).","type":"review"},{"id":"PA-chu-2025","title":"Wood-based solar interfacial evaporator for efficient seawater desalination processed by picosecond laser","authors":"Chu D. et al.","year":2025,"venue":"Langmuir","doi_or_url":"10.1021/acs.langmuir.5c03560","finding":"3.58 kg/m2/h indoors at 1 sun but 1.95 kg/m2/h outdoors: the lab-to-field gap in evaporation.","type":"experiment"},{"id":"PA-who-2020","title":"Domestic water quantity, service level and health, 2nd edition","authors":"Howard G., Bartram J., Williams A. et al.","year":2020,"venue":"World Health Organization","doi_or_url":"https://www.who.int/publications/i/item/9789240015241","finding":"Defines service-level tiers by litres per person per day (full text not retrieved; tiers used here are labelled unverified).","type":"standard"},{"id":"PA-nsf350","title":"NSF/ANSI 350 Onsite residential and commercial water reuse treatment systems","authors":"NSF International","year":2023,"venue":"NSF/ANSI standard","doi_or_url":"https://www.nsf.org/knowledge-library/nsf-ansi-350-onsite-residential-and-commercial-water-reuse-treatment-systems","finding":"Certification route used by Hydraloop (350R); effluent limits not retrieved (page 403).","type":"standard"},{"id":"PA-ca-dpr-2024","title":"Direct Potable Reuse regulations, CCR Title 22 sections 64669.00-64669.130","authors":"California State Water Resources Control Board","year":2024,"venue":"California Code of Regulations","doi_or_url":"https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/documents/direct_potable_reuse/sbddw-23-001-dpr-reg-text-oal-final.pdf","finding":"Treatment train validated for >= 20/14/15 log (virus/Giardia/Cryptosporidium) with >= 4 processes of >= 1 log each (max 6 per process) and 3 diverse mechanisms (membrane, chemical, UV >= 300 mJ/cm2); never below 16/10/11 log; LRV tracked continuously by SCADA surrogates; T5 chief and T3 shift operators required.","type":"regulation"},{"id":"PA-who-2017","title":"Potable reuse: guidance for producing safe drinking-water","authors":"World Health Organization","year":2017,"venue":"WHO manual (152 pp.)","doi_or_url":"https://www.who.int/publications/i/item/9789241512770","finding":"Frames potable reuse as a practical source in specific circumstances, managed through water safety plans, control measures, monitoring and public acceptance (catalogue summary only).","type":"guidance"},{"id":"PA-craig2018","title":"Towards development of a standard methodology for testing field performance of residential greywater reuse systems","authors":"Craig M, Richman R","year":2018,"venue":"Journal of Water Reuse and Desalination 8(2):135","doi_or_url":"10.2166/WRD.2017.020","finding":"Off-the-shelf household greywater systems have variable field performance; a field method measuring water balance, quality, energy, durability, maintenance, economics and satisfaction was applied in 22 homes (numeric savings truncated in the retrieved abstract).","type":"field study"}],"numbers":[{"id":"N01","label":"ISS total water recovery with Brine Processor","value":98,"unit":"%","basis":"measured","context":"Up from 93-94% before BPA; 2 lb lost per 100 lb collected.","sources":["src-nasa-98","src-ntrs-iss-2026"]},{"id":"N02","label":"ISS UPA recovery from US pretreated urine","value":87,"unit":"%","basis":"measured","context":"Design 85%, cut to 75% after 2009 urine-quality problems, restored by phosphate pretreat (2016); target 90%; Russian-segment urine 70%.","sources":["src-ntrs-iss-2026"]},{"id":"N03","label":"ISS WPA product water Feb 2024-Feb 2026","value":17900,"unit":"L (about 24.5 L/day)","basis":"measured","context":"Daily mean calculated as 17,900 L / 730 days.","sources":["src-ntrs-iss-2026"]},{"id":"N04","label":"ISS water use per crew member","value":"about 1","unit":"US gal/person/day (about 3.8 L)","basis":"reported","context":"Drinking, food preparation and hygiene; shows the floor of a closed-loop life.","sources":["src-nasa-98"]},{"id":"N05","label":"UN-recognised domestic water need","value":"50-100","unit":"L/person/day","basis":"reported","context":"UN GA resolution 64/292 (2010), read via secondary source. WHO 2020 service tiers not retrieved.","sources":["src-wiki-hrw"]},{"id":"N06","label":"Solar AWH design envelope (1 m2 device)","value":"0.2-2.5","unit":"L/kWh at 30-90% RH","basis":"target","context":"Needed to meet 5 L/person/day drinking water.","sources":["src-lord-2021"]},{"id":"N07","label":"Passive MOF-801 desert yield","value":0.1,"unit":"L/kg MOF/day","basis":"measured","context":"Arizona, sunlight only, one cycle.","sources":["src-fathieh-2018"]},{"id":"N08","label":"Passive MOF harvester, Death Valley","value":"up to 0.285","unit":"L/kg MOF/day","basis":"measured","context":"85-90% of captured vapour released as drinking water.","sources":["src-uc-deathvalley"]},{"id":"N09","label":"Active MOF-303 multicycle yield, Mojave","value":0.7,"unit":"L/kg MOF/day","basis":"measured","context":"At 10% RH; 1.3 L/kg/day at 32% RH indoors.","sources":["src-hanikel-2019"]},{"id":"N10","label":"Adaptive MOF device energy intensity","value":"1.67-5.25","unit":"kWh/L","basis":"measured","context":"3.5 L/kg/day at 17-32% RH.","sources":["src-almassad-2022"]},{"id":"N11","label":"Silica-gel sorption AWH energy efficiency","value":"0.46-1.5","unit":"L/kWh","basis":"measured","context":"13-35 C, 18-72% RH; 1 m2 PV gives 0.66-2 L/day.","sources":["src-li-2024-ohw"]},{"id":"N12","label":"Closed vs open regeneration loop heat demand","value":"2.7 vs 4.7","unit":"kWh_th/L","basis":"claimed","context":"Patent example assumes 45 C regeneration and 35 C condensation, 100 m3/h air (about 45 L/day over 8 h of solar heat); heat-source range stated 50-80 C.","sources":["src-pat-polito"]},{"id":"N13","label":"Fog collection yearly average","value":"3-10","unit":"L/m2/day","basis":"measured","context":"Operational projects worldwide.","sources":["src-klemm-2012"]},{"id":"N14","label":"Seawater RO electricity","value":"3-5.5","unit":"kWh/m3","basis":"reported","context":"Thermodynamic minimum about 1 kWh/m3; i.e. 0.003-0.0055 kWh/L, about 300-1,000x less than AWH.","sources":["src-wiki-desal"]},{"id":"N15","label":"PV-ED direct-drive output","value":"up to 5000","unit":"L/day","basis":"measured","context":"Over 94% of PV electricity used directly, no battery, six months, brackish wells.","sources":["src-mit-pved-2024"]},{"id":"N16","label":"WOTA Unit domestic wastewater regeneration","value":97,"unit":"%","basis":"claimed","context":"Vendor figure, 'may vary with usage'. TRL 6 passed 2025 (press). Drinking-water make-up depends on a rainwater purification module still in development per Feb 2026 press; WOTA site claims WHO-guideline quality.","sources":["src-wota-site","src-dailygalaxy-wota"]},{"id":"N17","label":"Hydraloop greywater recycled / mains reduction","value":"95 / 45","unit":"% (up to)","basis":"claimed","context":"NSF/ANSI 350R certified, H600 up to 720 L/day.","sources":["src-hydraloop-site"]},{"id":"N18","label":"Single-house MBR COD removal","value":87,"unit":"%","basis":"measured","context":"TSS 95 to 8 mg/L.","sources":["src-fountoulakis-2016"]},{"id":"N19","label":"Soft-sensor false-positive ceiling","value":2,"unit":"% max","basis":"measured","context":"Free chlorine + ORP logistic regression on MBR-chlorination disruptions.","sources":["src-reynaert-2023"]},{"id":"N20","label":"Urine nutrient load","value":"11 g N, 1.0 g P","unit":"per person per day","basis":"reported","context":"Theoretical; 38-63% of N recovered in practice in Sweden.","sources":["src-zeeman-2011"]},{"id":"N21","label":"Urine volume","value":500,"unit":"L/person/year","basis":"reported","context":"About 1.4 L/person/day.","sources":["src-vuna-aurin"]},{"id":"N22","label":"Urine distillation energy","value":71,"unit":"W/capita (primary)","basis":"measured","context":"Plus 13 W/capita nitrification, i.e. about 2 kWh/capita/day primary.","sources":["src-fumasoli-2016"]},{"id":"N23","label":"Vacuum toilet flush volume","value":"0.5-1.2","unit":"L/flush","basis":"measured","context":"Conventional 5-9 L/flush.","sources":["src-gao-2019"]},{"id":"N24","label":"SOURCE hydropanel field output","value":"about 1","unit":"US gal/panel/day","basis":"reported","context":"Allensworth, CA; many panels broken and unserviced in 2024.","sources":["src-sjv-allensworth"]},{"id":"N25","label":"Atoco container output","value":"2,000-4,000 (grid) / 1,000 (off-grid)","unit":"L/day","basis":"claimed","context":"20-ft containerised unit; article of 21 Jan 2026 says commercial rollout aimed 'within the next year' (no fixed year).","sources":["src-agnav-atoco"]},{"id":"N26","label":"Uravu Clausius output per MW","value":30000,"unit":"L per MW per day (site does not say whether MW is heat load or IT load)","basis":"claimed","context":"35-60 C waste heat.","sources":["src-uravu-site"]},{"id":"N27","label":"Outdoor interfacial evaporation rate","value":1.95,"unit":"kg/m2/h","basis":"measured","context":"Same device 3.58 kg/m2/h indoors.","sources":["src-chu-2025-langmuir"]},{"id":"N28","label":"Latent heat of water as electrical floor for dewing AWG before COP","value":0.68,"unit":"kWh/L","basis":"calculated","context":"2.45 MJ/kg / 3.6 MJ/kWh; divide by compressor COP 2-4 for best-case humid air.","sources":[]},{"id":"N29","label":"ORIJO 4-person make-up water (desert)","value":44,"unit":"L/day","basis":"calculated","context":"4 x (80 L x (1-0.90) + 3 L drinking/cooking).","sources":["src-anyground-v3"]},{"id":"N30","label":"Energy to make 44 L/day by sorption AWH vs desalination","value":"18-220 vs 0.13-0.24","unit":"kWh/day","basis":"calculated","context":"AWH at 0.2-2.5 L/kWh (N06); SWRO at 3-5.5 kWh/m3 (N14).","sources":["src-lord-2021","src-wiki-desal"]},{"id":"NG-01","label":"California DPR pathogen log-reduction design target (enteric virus / Giardia / Cryptosporidium)","value":"20 / 14 / 15","unit":"log10 reduction","basis":"reported","context":"CCR 22 s.64669.45(a)(1); >= 4 processes per pathogen each credited >= 1.0 and <= 6 log; 3 diverse mechanisms (membrane, chemical, UV); regulation text read","sources":["src-ca-dpr-text"]},{"id":"NG-02","label":"California DPR never-below floor","value":"16 / 10 / 11","unit":"log10 reduction","basis":"reported","context":"Must be met at all times (s.64669.45(b)(2)); full 20/14/15 at least 90% of production time (b)(3); LRV tracked continuously by SCADA via surrogates (b)(1)","sources":["src-ca-dpr-text"]},{"id":"NG-03","label":"Minimum UV dose in a California DPR train","value":300,"unit":"mJ/cm2","basis":"reported","context":"s.64669.45(a)(7)","sources":["src-ca-dpr-text"]},{"id":"NG-04","label":"Certified operators required for a California DPR plant","value":"T5 chief + T3 per shift","unit":"operator grade","basis":"reported","context":"s.64669.35(b); plus AWT5/AWT3 for the advanced treatment plant (c). Municipal scope only; no household potable-reuse pathway exists in this rule","sources":["src-ca-dpr-text"]},{"id":"NG-05","label":"Japanese mobile disaster water purifier: cost and capacity","value":"tens of millions to 100 million JPY; about 2,000 L/h","unit":"JPY per unit; L/h","basis":"reported","context":"Ministry figures via Yomiuri, Sep 2026; one-third purchase subsidy for prefectures from FY2025; Suzu still using three units after the 2024 Noto earthquake","sources":["src-ann-japan-purifiers"]}],"failures":[{"what":"SOURCE hydropanels in Allensworth, California","why":"Many panels broke; community-centre panels down for months; contract had no reachable support; output about a gallon per panel versus a town need of 1.5 million gallons per month.","lesson_for_anyground":"Sell service, not panels: every water module ships with remote telemetry, a stocked spare kit and a guaranteed response time, and is sized against the residual, not the whole demand."},{"what":"ISS UPA recovery cut from 85% to 75% (2009)","why":"Issues with urine quality (per the 2026 status paper) forced recovery down until a phosphate-based pretreat was introduced in 2016.","lesson_for_anyground":"Brine chemistry, not membranes, limits recovery; design urine and RO-reject paths with acid flush and conservative recovery set-points that rise only with data."},{"what":"ISS Universal Waste Management System toilet in stand-down","why":"Failed dose pump and controller; no direct monitoring of pretreat dose quality; fluid releases limited crew use.","lesson_for_anyground":"Every chemical dose needs a sensor that confirms it was delivered; KAWAYA-U must detect a missed acid or flush dose."},{"what":"ISS UPA purge pump failures 2024-26 and 300 L urine backlog","why":"Peristaltic tubing ruptures and motor failures in five pump swaps; stored urine aged and needed a flight-rule waiver.","lesson_for_anyground":"Plan for the loop being down: buffer tanks with stabilised storage, and wear parts (tubing, pumps) as robot-swappable cartridges for TSURU."},{"what":"Russian-segment urine processor distiller failed at checkout (2018)","why":"Hardware failures and vacuum leaks.","lesson_for_anyground":"Vacuum distillation is unforgiving; prefer ambient-pressure membrane distillation for household brine."},{"what":"Blue Diversion Autarky toilet (Eawag/EOOS)","why":"Treated wash water regrew pathogens in storage; cost and space concerns from users; project did not reach market.","lesson_for_anyground":"Always carry a residual disinfectant or recirculating UV in storage; test business model with users early."},{"what":"VUNA nitrification process failures","why":"Nitrite accumulation and selection of acid-tolerant ammonia oxidisers, especially at start-up; distillation energy 4-5x conventional nutrient removal.","lesson_for_anyground":"Use electrochemical pH control and nitrite sensors; consider zeolite capture (M06) where energy is short; supervise start-up remotely."},{"what":"Constructed wetlands as sole greywater barrier","why":"Cannot reliably meet microbiological reuse standards.","lesson_for_anyground":"Wetlands are biology, not disinfection; always add UV and residual."},{"what":"AWG industry energy opacity","why":"Watergen, Genaq and Aquaria sites read give no kWh/L; claims like 'works below 20% RH' come without data.","lesson_for_anyground":"Publish measured litres per kWh per climate for every KUMO unit; it is a trust differentiator."},{"what":"Lab-to-field gap in solar evaporation and MOF yields","why":"Indoor 3.58 vs outdoor 1.95 kg/m2/h; lab MOF projections of 2.8 L/kg/day vs field 0.1-0.7.","lesson_for_anyground":"Size from single-cycle field data only (as M05 already does)."}],"interfaces":[{"with_layer":"energy","exchange":"kWh in (treatment pumps, UV, sorption fans, desalination), low-grade heat in (heat pump hot side, PV-T, battery cooling), thermal storage via water tanks","design_rule":"Run discretionary water work (AWH desorption, brine drying, distillation) only on PV surplus or free heat; essential potable path must run on <= 1 kWh/day per person from the battery."},{"with_layer":"grow","exchange":"Nitrified urine and treated grey as nutrient solution; transpiration condensate back; irrigation demand curve","design_rule":"Treat the farm as the primary atmospheric water source: dehumidify grow air at 70-90% RH before ever pulling desert air."},{"with_layer":"loop","exchange":"Urine N/P/K, brine salt, sludge, BSF frass leachate","design_rule":"Every residual stream has a named product or a regulated export; no stream ends in 'drain'."},{"with_layer":"care","exchange":"Drinking-water safety verdicts, hygiene water, outbreak signals (wastewater surveillance)","design_rule":"Potable release requires a positive verdict from independent barriers; any doubt routes to grey, never to tap."},{"with_layer":"mind","exchange":"Sensor streams (free Cl, ORP, EC, turbidity, UVT, TOC, level, flow), weather forecasts, setpoints, alarms","design_rule":"Soft-sensor models run at the edge with a fixed false-positive ceiling (<= 2%); cloud is for fleet learning, not for safety."},{"with_layer":"build","exchange":"Labour: cartridge swaps (filters, UV, membranes, pump tubing), leak tests at JO-PORT","design_rule":"All wear parts are front-access cartridges under 15 kg with dry-break couplers, so TSURU or a guest can swap them."},{"with_layer":"structure","exchange":"Roof area for rain and dew, wing area for fog and solar thermal, tank mass on the mast and legs","design_rule":"Fold geometry must keep a continuous fall line from every roof facet to a gutter in deployed state; tanks sit on ASHI-rated nodes."}],"autonomy_ladder":[{"level":"L0","description":"Mains or trucked water, manual filters, no reuse.","human_minutes_per_week":0,"enabling_tech":"None; dependent on utility."},{"level":"L1","description":"Rain tank plus certified greywater recycler for toilets and laundry, alarms by SMS.","human_minutes_per_week":30,"enabling_tech":"Hydraloop-class appliance, float switches, UV lamp."},{"level":"L2","description":"Greywater-to-potable appliance with autonomous control, online EC/turbidity/free Cl, remote fleet monitoring; owner swaps cartridges.","human_minutes_per_week":20,"enabling_tech":"WOTA Unit-class, JO-PORT dry-break cartridges."},{"level":"L3","description":"Source-separated streams (urine nitrification, BSF, grey) plus one make-up source sized to the residual, soft-sensor release interlock, predictive cartridge ordering.","human_minutes_per_week":10,"enabling_tech":"Reynaert-type soft sensor, KAWAYA-U, MIZU-1, KUMO-12 or rain."},{"level":"L4","description":"Closed loop at 95-98% with brine drying and farm transpiration recapture; robot swaps cartridges; human role is quarterly verification sampling.","human_minutes_per_week":5,"enabling_tech":"BPA-analogue brine bladder, TSURU cartridge handling, optical bacteria counter."},{"level":"L5","description":"Self-sizing fleet: units negotiate water and spare parts across sites, adapt AWH cycles to forecasts, and certify their own compliance via sealed sensor logs accepted by regulators.","human_minutes_per_week":1,"enabling_tech":"Regulatory acceptance of continuous-monitoring compliance (not yet available), fleet ML, adaptive AWH control."}],"orijo_design":{"recommended_stack":[{"subsystem":"WATER-S5 reuse","choice":"MIZU-1 household wastewater regeneration organ (WOTA Unit class; potable release only behind MIZU-MAMORI, since no product has independently proven potable reuse) + KAWAYA-U urine diversion with nitrification route","why":"Recovery multiplies every other source: at 90% net recovery the make-up need falls 10x."},{"subsystem":"WATER-S1 sources","choice":"Rain capture on every roof facet as default; fog harp on Miura wing only after a 12-month standard fog collector survey","why":"Lowest kWh per litre; fog is excellent where it works and useless elsewhere."},{"subsystem":"WATER-S3 desalination","choice":"Small PV-RO or PV-ED when any saline/brackish source exists (coast, brackish well)","why":"3-5.5 kWh/m3 versus 400-5,000 kWh/m3 for AWH."},{"subsystem":"WATER-S2 AWH","choice":"KUMO-12 sorption rack only for E3 desert / no-source sites, sized to drinking + residual; regenerate with heat-pump or PV-T waste heat in a closed vapour loop","why":"Field yields are 0.1-0.7 L/kg/day; closed regeneration loop cuts heat need about 40% (2.7 vs 4.7 kWh_th/L claimed)."},{"subsystem":"WATER-S4 barriers","choice":"Biology > UF > RO > UV-C LED > electrochlorinated residual > GAC on drinking tap","why":"Independent barriers; residual needed against regrowth in storage."},{"subsystem":"WATER-S6 monitoring","choice":"Free Cl + ORP + EC + turbidity + UVT with slope features, logistic soft sensor at FPR <= 2%, membrane pressure-decay test daily","why":"Cheapest proven predictor of microbial safety in on-site reuse."},{"subsystem":"WATER-S7 storage and residuals","choice":"KRES-7 gravity tank with recirculating UV; brine bladder dryer (BPA analogue) on PV surplus","why":"Pushes net recovery from 90-95% toward 98%, and leaves salt cake, not liquid reject."}],"new_mechanisms_or_modules":[{"name":"KUMO-NAE (the farm cloud)","what":"Desiccant cassette that harvests water from the HATA/YOSHI-6G grow air instead of outside air.","how_it_works":"Grow chambers sit at 70-90% RH because plants transpire most of the irrigation water. A rotating silica-gel or MOF-303 cassette loads from grow air at night, is regenerated by the heat pump's hot side (45-60 C) in a closed vapour loop, and condenses on the heat pump's cold side, so one compressor dehumidifies the farm, heats the hot water tank and makes water. Condensate goes to the grey loop (Legionella and organics risk), not straight to the tap. The SOURCE patent US11160223B2 describes the farm-air coupling; the closed regeneration loop follows PoliTo CN111278532B.","prototype_12mo":{"build":"One HATA-4 cassette in a sealed 1-jo chamber with load cells on trays, a 1.5 kg silica-gel wheel, a 1 kW R290 heat pump, condensate scale and RH/T sensors.","bom_usd":"about 6,000 (estimate, not quoted)","test":"Run 90 days of lettuce; measure litres recovered / litres irrigated, kWh/L, and condensate HPC/Legionella monthly.","pass":">= 80% of irrigation water recovered at <= 0.5 kWh/L with no Legionella detection after UV.","kill":"< 60% recovery or > 1 kWh/L, or recurrent Legionella."}},{"name":"SHIO-BUKURO (salt bag)","what":"Household brine bladder that dries RO reject and urine brine to salt cake, after ISS BPA.","how_it_works":"A replaceable hydrophobic-membrane bag holds brine; warm dry air from the PV-T loop flows over it so water vapour crosses the membrane while salts stay inside. The humid air is returned to the HRV dehumidifier and the condensate joins the grey loop. When the bag's mass stops falling, TSURU swaps it; the dry cake goes to salt or fertiliser export.","prototype_12mo":{"build":"20 L bag of PTFE or ePTFE laminate in a ventilated 1-jo locker with a 300 W heater fan on PV surplus and a load cell.","bom_usd":"about 1,500 (estimate)","test":"Feed WOTA-class RO reject and stored urine brine for 6 months.","pass":">= 80% of brine water recovered, no membrane wetting, odour below household threshold.","kill":"Membrane wetting within 4 weeks or > 3 kWh per litre recovered."}},{"name":"MIZU-MAMORI (water guardian)","what":"Fail-closed release controller that decides tap, farm or grey for every tank batch.","how_it_works":"Batches, not continuous flow: each storage batch is held until free chlorine, ORP (and their slopes), EC, turbidity and UV-sensor readings feed a logistic model trained to FPR <= 2%; only a 'safe' verdict opens the potable solenoid, otherwise the batch recirculates or goes grey. Weekly, a sealed grab-sample vial is drawn automatically for E. coli testing to recalibrate. Logs are hash-chained for regulators.","prototype_12mo":{"build":"Sensor manifold (free Cl, ORP, EC, turbidity, UVT), 3 solenoids, edge controller, auto-sampler on a MIZU-1 test loop.","bom_usd":"about 4,000 (estimate)","test":"Induce the six disruption types from Reynaert 2023 (membrane breach, chlorine dosing failure, etc.) 50 times.","pass":"Zero unsafe batches released; false alarm rate below 10%.","kill":"Any unsafe release that grab samples detect."}},{"name":"AMA-TSUYU roof (rain-and-dew roof)","what":"Folded roof facets with a radiative-cooling, slippery hydrophilic top coat that collects rain by day and dew by night into one gutter with first-flush.","how_it_works":"The same facets that shed rain are tilted at 30 degrees or more to drain dew; the coating emits in the 8-13 um sky window to cool below dew point at night. Gutter flow sensors separate rain, dew and first flush.","prototype_12mo":{"build":"Two 1x2 m coated facets vs uncoated control at a coastal and a steppe site, tipping-bucket gauges.","bom_usd":"about 2,500 (estimate)","test":"12 months of paired data per the 2025 dew measurement standard.","pass":">= 0.1 L/m2/night annual mean added on the coated facet without hurting roof thermal performance in summer.","kill":"< 0.03 L/m2/night or coating soiling > 30% loss in emissivity in 6 months."}}],"sizing_reference":{"home_4p":{"formula":"make_up = N x (D x (1 - R) + Dk); treat = N x D","inputs":{"N":4,"D_L_per_person_day":80,"R_net_recovery":0.9,"Dk_drinking_cooking_L":3},"treat_L_day":320,"make_up_L_day":44,"source_options":{"rain_needed_roof_m2_at_100mm_yr":"44 x 365 / (100 x 0.8) = 201 m2 (desert: rain alone insufficient)","rain_needed_roof_m2_at_600mm_yr":"44 x 365 / (600 x 0.8) = 33 m2","MOF_passive_kg_at_0.1-0.285_L_kg_day":"154-440 kg","sorption_AWH_kWh_day_at_0.2-2.5_L_kWh":"18-220","SWRO_kWh_day":"0.13-0.24"},"basis":"calculated","sources":["src-anyground-v3","src-fathieh-2018","src-uc-deathvalley","src-lord-2021","src-wiki-desal"]},"hotel_6key":{"formula":"same; guests G = 12 at D = 100 L, staff 2 at 50 L","treat_L_day":1300,"make_up_L_day":"12 x (100 x 0.1 + 3) + 2 x (50 x 0.1 + 3) = 172","equipment":"2 x 720 L/day greywater appliances (Hydraloop H600-class capacity) or two MIZU-1 organs; urine to Aurin-type route or zeolite bed; brackish PV-ED if a well exists","basis":"calculated","sources":["src-hydraloop-site","src-wota-site"]},"farm_module":{"formula":"net = A_grow x ET x (1 - r_condensate) + biomass water","inputs":{"A_grow_m2":6.6,"ET_L_m2_day_assumed":"2-4 (assumption, not sourced)","r_condensate":0.9,"biomass_fresh_kg_day":0.5,"water_content":0.95},"net_L_day":"6.6 x 2-4 x 0.1 + 0.475 = 1.8-3.1","nutrient_supply":"4 persons x 11 g N/day urine = 44 g N/day available vs a few g N/day for one rack (M06 already notes surplus)","basis":"calculated (ET assumption labelled)","sources":["src-zeeman-2011","src-pat-source"]}}},"open_problems":["No household greywater-to-potable appliance has long-term (multi-year) independent safety data; WOTA household trials began January 2026.","Online, low-cost, pathogen-specific sensing (E. coli, viruses, protozoa) does not exist; all release logic relies on proxies.","Regulators do not yet accept continuous-sensor logs in lieu of lab sampling for on-site potable reuse.","MOF cost, dust fouling and multi-year cycling stability in real deserts are not established; vendor yields (Atoco, AirJoule, Uravu) lack independent kWh/L data.","Brine and urine concentrate scaling (struvite, calcium salts) still limits recovery above 95% outside spacecraft.","Legionella risk in farm-condensate and warm storage loops in small buildings is poorly quantified.","Seasonal storage: rain and fog arrive in seasons; a 2,000 L tank covers about 45 days of a 4-person desert make-up only.","WHO 2020 service tiers and NSF/ANSI 350 numeric limits were not retrieved in this sweep and must be read from the primary documents before certification planning.","California DPR (2024) requires certified T5/T3 human operators on every shift for municipal potable reuse; no jurisdiction found with a household potable-reuse certification path. [gaps-2026-10-29]"],"sources":[{"id":"src-nasa-98","title":"NASA Achieves Water Recovery Milestone on International Space Station (2023, updated 2026)","url":"https://www.nasa.gov/missions/station/iss-research/nasa-achieves-water-recovery-milestone-on-international-space-station","type":"agency","accessed":"2026-10-29","read_primary":true},{"id":"src-ntrs-iss-2026","title":"Williamson, Wilson, Luong, Chen - Status of ISS Water Management and Recovery, ICES-2026-425","url":"https://ntrs.nasa.gov/api/citations/20260004140/downloads/2026%20Status%20of%20ISS%20Water%20FINAL.pdf","type":"agency","accessed":"2026-10-29","read_primary":true},{"id":"src-lord-2021","title":"Lord et al. 2021 - Global potential for harvesting drinking water from air using solar energy, Nature 598:611","url":"https://doi.org/10.1038/s41586-021-03900-w","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-kim-2017","title":"Kim et al. 2017 - Water harvesting from air with metal-organic frameworks powered by natural sunlight, Science","url":"https://doi.org/10.1126/science.aam8743","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-kim-2018","title":"Kim et al. 2018 - 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Environmentally adaptive MOF-based device enables continuous self-optimizing AWH, Nat Commun","url":"https://doi.org/10.1038/s41467-022-32642-0","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-li-2024-ohw","title":"Li Q. et al. 2024 - AWH system based on the Optimal Harvesting Window design, Science Bulletin","url":"https://doi.org/10.1016/j.scib.2024.03.018","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-lin-2025-p2w","title":"Lin H. et al. 2025 - Multi-stage power-to-water battery, Nat Commun","url":"https://doi.org/10.1038/s41467-025-66053-8","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-yang-2024-hipg","title":"Yang X. et al. 2024 - Enhanced continuous AWH with scalable hygroscopic gel driven by sunlight and wind, Nat Commun","url":"https://doi.org/10.1038/s41467-024-52137-4","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-li-2018-hydrogel","title":"Li R. et al. 2018 - Hybrid hydrogel for deployable solar-driven atmospheric water generator, Environ Sci Technol","url":"https://doi.org/10.1021/acs.est.8b02852","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-tashtoush-2024","title":"Tashtoush & Alshoubaki 2024 - Solar-off-grid AWH system performance in diverse climates, Sci Total Environ","url":"https://doi.org/10.1016/j.scitotenv.2023.167804","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-tao-2026","title":"Tao et al. 2026 - Copper foam-integrated zwitterionic cellulose aerogels for AWH, ACS AMI","url":"https://doi.org/10.1021/acsami.6c14519","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-li-wang-2023-review","title":"Li R. & Wang P. 2023 - Sorbents, processes and applications beyond water production in sorption-based AWH, Nature Water","url":"https://www.nature.com/articles/s44221-023-00099-0","type":"paper","accessed":"2026-10-29","read_primary":false},{"id":"src-ejeian-2021","title":"Ejeian & Wang 2021 - Adsorption-based atmospheric water harvesting, Joule","url":"https://www.cell.com/joule/fulltext/S2542-4351(21)00178-1","type":"paper","accessed":"2026-10-29","read_primary":false},{"id":"src-klemm-2012","title":"Klemm et al. 2012 - Fog as a fresh-water resource: overview and perspectives, Ambio 41:221","url":"https://doi.org/10.1007/s13280-012-0247-8","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-beysens-2025","title":"Beysens et al. 2025 - A standard for dew measurement, J Hydrology","url":"https://www.sciencedirect.com/science/article/pii/S0022169425008650","type":"paper","accessed":"2026-10-29","read_primary":false},{"id":"src-chu-2025-langmuir","title":"Chu et al. 2025 - Wood-based solar interfacial evaporator processed by picosecond laser, Langmuir","url":"https://doi.org/10.1021/acs.langmuir.5c03560","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-sie-review-2025","title":"Solar-driven interfacial evaporation technologies for food, energy and water, Nat Rev Clean Technol 2025","url":"https://doi.org/10.1038/s44359-024-00009-x","type":"paper","accessed":"2026-10-29","read_primary":false},{"id":"src-wiki-desal","title":"Wikipedia - Desalination (energy table citing IWA and Panagopoulos 2020)","url":"https://en.wikipedia.org/wiki/Desalination","type":"web (encyclopedia)","accessed":"2026-10-29","read_primary":true},{"id":"src-elimelech-2011","title":"Elimelech & Phillip 2011 - The future of seawater desalination: energy, technology and the environment, Science 333:712","url":"https://doi.org/10.1126/science.1200488","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-mit-pved-2024","title":"MIT News 2024 - Solar-powered desalination system requires no extra batteries (Bessette, Pratt, Winter, Nature Water)","url":"https://news.mit.edu/2024/solar-powered-desalination-system-requires-no-extra-batteries-1008","type":"news","accessed":"2026-10-29","read_primary":true},{"id":"src-li-2009-greywater","title":"Li, Wichmann, Otterpohl 2009 - Review of technological approaches for grey water treatment and reuses, Sci Total Environ","url":"https://doi.org/10.1016/j.scitotenv.2009.02.004","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-fountoulakis-2016","title":"Fountoulakis et al. 2016 - Single house on-site grey water treatment using a submerged MBR, Sci Total Environ","url":"https://doi.org/10.1016/j.scitotenv.2016.02.057","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-arden-ma-2018","title":"Arden & Ma 2018 - Constructed wetlands for greywater recycle and reuse: a review, Sci Total Environ","url":"https://doi.org/10.1016/j.scitotenv.2018.02.218","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-reynaert-2023","title":"Reynaert et al. 2023 - Predicting microbial water quality in on-site water reuse systems with online sensors, Water Research","url":"https://doi.org/10.1016/j.watres.2023.120075","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-hojris-2016","title":"Hojris et al. 2016 - A novel optical on-line bacteria sensor for monitoring drinking water quality, Sci Rep","url":"https://doi.org/10.1038/srep23935","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-song-2016-uvled","title":"Song, Mohseni, Taghipour 2016 - Application of UV-LEDs for water disinfection: a review, Water Research","url":"https://doi.org/10.1016/j.watres.2016.03.003","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-hijnen-2006","title":"Hijnen et al. 2006 - Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo)cysts: a review, Water Research","url":"https://doi.org/10.1016/j.watres.2005.10.030","type":"paper","accessed":"2026-10-29","read_primary":false},{"id":"src-udert-2012","title":"Udert & Waechter 2012 - 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Resource recovery from source separated domestic waste(water) streams; full scale results, WST","url":"https://doi.org/10.2166/wst.2011.562","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-zeeman-2008","title":"Zeeman et al. 2008 - Anaerobic treatment as a core technology for energy, nutrients and water recovery from source-separated domestic waste(water), WST","url":"https://doi.org/10.2166/wst.2008.101","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-gao-2019","title":"Gao et al. 2019 - Anaerobic treatment of blackwater from different toilet flushing systems, J Hazard Mater","url":"https://doi.org/10.1016/j.jhazmat.2018.10.055","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-nguyen-2017","title":"Nguyen et al. 2017 - Controlling bacterial pathogens in water for reuse in the Blue Diversion Autarky Toilet, Front Environ Sci","url":"https://doi.org/10.3389/fenvs.2017.00090","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-tobias-2017","title":"Tobias et al. 2017 - Early testing of new sanitation technology for urban slums: Blue Diversion Toilet, Sci Total Environ","url":"https://doi.org/10.1016/j.scitotenv.2016.10.057","type":"paper","accessed":"2026-10-29","read_primary":true},{"id":"src-melissa-esa","title":"ESA - MELiSSA programme page","url":"https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Melissa","type":"agency","accessed":"2026-10-29","read_primary":true},{"id":"src-melissa-2026","title":"Arnau, Godia et al. 2026 - Complete gas closure and liquid integration for air revitalization and food production in the MELiSSA Pilot Plant (COSPAR abstract) [unverified: ADS page not retrievable on 2026-10-29]","url":"https://ui.adsabs.harvard.edu/abs/2026cosp...46.2652A/abstract","type":"paper","accessed":"2026-10-29","read_primary":false},{"id":"src-wota-site","title":"WOTA Corp. official site (WOSH, WOTA BOX, WOTA Unit)","url":"https://www.wota.co.jp/en/","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-dailygalaxy-wota","title":"The Daily Galaxy 2026 - Japan built a home machine that purifies and reuses almost all household water (WOTA Unit)","url":"https://dailygalaxy.com/2026/02/japan-home-water-recycling-machine-no-more-pipes/","type":"news","accessed":"2026-10-29","read_primary":true},{"id":"src-hydraloop-site","title":"Hydraloop official site (H300/H600 specs, certifications)","url":"https://www.hydraloop.com/","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-hydraloop-brochure","title":"Hydraloop distributor brochure (e-terratech, 2023)","url":"https://e-terratech.com.au/wp-content/uploads/2023/04/Greywater_Recycling_Brochure.pdf","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-sjv-allensworth","title":"SJV Water 2024 - Allensworth residents feel abandoned by company that makes water out of thin air","url":"https://sjvwater.org/allensworth-residents-feel-abandoned-by-company-that-makes-water-out-of-thin-air/","type":"news","accessed":"2026-10-29","read_primary":true},{"id":"src-cnbc-source-2022","title":"CNBC 2022 - 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Uravu Labs raises $2.3 Mn in seed round (headline only)","url":"https://entrackr.com/2023/03/deeptech-startup-uravu-labs-raises-2-3-mn-in-seed-round/","type":"news","accessed":"2026-10-29","read_primary":false},{"id":"src-technically-airjoule","title":"Technical.ly 2026 - This machine in Delaware turns data center heat into water (AirJoule Prime)","url":"https://technical.ly/entrepreneurship/airjoule-turning-industrial-heat-waste-into-water/","type":"news","accessed":"2026-10-29","read_primary":true},{"id":"src-agnav-atoco","title":"AgNavigator 2026 - Atoco targets commercial rollout of atmospheric water harvesting tech following Nobel Prize","url":"https://www.agnavigator.com/Article/2026/01/21/atoco-targets-commercial-rollout-of-atmospheric-water-harvesting-tech-following-nobel-prize/","type":"news","accessed":"2026-10-29","read_primary":true},{"id":"src-watergen-site","title":"Watergen official site","url":"https://www.watergen.com/","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-genaq-site","title":"GENAQ official site","url":"https://www.genaq.com/","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-aquaria-site","title":"Aquaria official site (Hydropack)","url":"https://aquaria.world/","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-solardew-site","title":"SolarDew official site","url":"https://www.solardew.com/","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-who-2020","title":"Howard et al. (WHO) 2020 - Domestic water quantity, service level and health, 2nd ed.","url":"https://www.who.int/publications/i/item/9789240015241","type":"standard","accessed":"2026-10-29","read_primary":false},{"id":"src-wiki-hrw","title":"Wikipedia - Human right to water and sanitation (UN GA Res. 64/292: 50-100 L/person/day)","url":"https://en.wikipedia.org/wiki/Human_right_to_water_and_sanitation","type":"standard","accessed":"2026-10-29","read_primary":true},{"id":"src-who-gdwq","title":"WHO Guidelines for Drinking-water Quality, 4th ed. incorporating addenda","url":"https://www.who.int/publications/i/item/9789240045064","type":"standard","accessed":"2026-10-29","read_primary":false},{"id":"src-nsf-350","title":"NSF/ANSI 350 Onsite residential and commercial water reuse treatment systems","url":"https://www.nsf.org/knowledge-library/nsf-ansi-350-onsite-residential-and-commercial-water-reuse-treatment-systems","type":"standard","accessed":"2026-10-29","read_primary":false},{"id":"src-yt-yaghi-desert","title":"YouTube - 'This water harvester can turn desert air into drinkable water' (UC Berkeley, Arizona desert prototype)","url":"https://www.youtube.com/watch?v=-6T3ICXWqjc","type":"video","accessed":"2026-10-29","read_primary":false},{"id":"src-yt-wota-unit","title":"YouTube - 'The world's first Residential Water Regeneration System WOTA Unit (English)'","url":"https://www.youtube.com/watch?v=3SDaU2mD75E","type":"video","accessed":"2026-10-29","read_primary":false},{"id":"src-yt-wota-box","title":"YouTube - SoftBank exhibit of WOTA BOX water circulation shower, RISCON Tokyo 2022","url":"https://www.youtube.com/watch?v=fAtOliBn64Y","type":"video","accessed":"2026-10-29","read_primary":false},{"id":"src-yt-iss-hadfield","title":"YouTube - 'Water Recycling on the ISS' (CSA astronaut Chris Hadfield, 2013)","url":"https://www.youtube.com/watch?v=BCjH3k5gODI","type":"video","accessed":"2026-10-29","read_primary":false},{"id":"src-yt-source-dubai","title":"YouTube - 'Here's how a Dubai farm makes water from sunlight and air' (SOURCE Global)","url":"https://www.youtube.com/watch?v=oDa4HdUEjyw","type":"video","accessed":"2026-10-29","read_primary":false},{"id":"src-yt-airjoule","title":"YouTube - 'AirJoule: Inside the world's most efficient Atmospheric Water Harvester'","url":"https://www.youtube.com/watch?v=7x_wuC2Cnrs","type":"video","accessed":"2026-10-29","read_primary":false},{"id":"src-anyground-v3","title":"Anyground v3 concept.json (internal: MIZU-1, KUMO-12, M05, M06)","url":"research/v3/concept.json","type":"company","accessed":"2026-10-29","read_primary":true},{"id":"src-bwdisrupt-uravu-2025","title":"BW Disrupt 2025 - Climate tech startup Uravu Labs secures funding from Enrission India Capital (headline only; page returned 403)","url":"https://www.bwdisrupt.com/article/climate-tech-startup-uravu-labs-secures-funding-from-enrission-india-capital-562993","type":"news","accessed":"2026-10-29","read_primary":false},{"id":"src-ca-dpr-page","title":"California State Water Resources Control Board - Direct Potable Reuse (adoption 19 Dec 2023; effective 1 Oct 2024; OAL approval 6 Aug 2024)","url":"https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/direct_potable_reuse.html","type":"regulator","accessed":"2026-10-29","read_primary":true,"added_by":"gaps-2026-10-29"},{"id":"src-ca-dpr-text","title":"SWRCB SBDDW-23-001 Direct Potable Reuse final regulation text, CCR Title 22 sections 64669.00-64669.130 (June 2024, 63 pp.; read sections 64669.35 and 64669.45)","url":"https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/documents/direct_potable_reuse/sbddw-23-001-dpr-reg-text-oal-final.pdf","type":"regulation","accessed":"2026-10-29","read_primary":true,"added_by":"gaps-2026-10-29"},{"id":"src-who-potable-reuse-2017","title":"WHO (2017) Potable reuse: guidance for producing safe drinking-water, ISBN 978-92-4-151277-0 (catalogue page)","url":"https://www.who.int/publications/i/item/9789241512770","type":"agency","accessed":"2026-10-29","read_primary":true,"added_by":"gaps-2026-10-29"},{"id":"src-eu-reuse-2020-741","title":"European Commission - Water reuse (Regulation (EU) 2020/741, applies from 26 June 2023, agricultural irrigation only)","url":"https://environment.ec.europa.eu/topics/water/water-reuse_en","type":"regulator","accessed":"2026-10-29","read_primary":true,"added_by":"gaps-2026-10-29"},{"id":"src-craig-richman-2018","title":"Craig & Richman (2018) Towards development of a standard methodology for testing field performance of residential greywater reuse systems: 22 homes in Southern Ontario, J. Water Reuse Desal. 8(2):135 (abstract via Elicit, truncated; publisher page 403)","url":"https://doi.org/10.2166/WRD.2017.020","type":"paper","accessed":"2026-10-29","read_primary":false,"added_by":"gaps-2026-10-29"},{"id":"src-ann-japan-purifiers","title":"Asia News Network / Yomiuri (2 Sep 2026) Japan government to boost water supply capacity during disasters","url":"https://asianews.network/japan-government-to-boost-water-supply-capacity-during-disasters/","type":"news","accessed":"2026-10-29","read_primary":true,"added_by":"gaps-2026-10-29"}],"method_note":"Searches: 12 Elicit queries and 48 SerpApi calls (helper-logged in research/v4/sweep/raw-water.jsonl; 10 early patent/YouTube calls failed with HTTP 400 and still consumed budget). Primary reading via WebFetch and Europe PMC abstracts (accessed 2026-10-29). Nature, Guardian, NSF, WHO IRIS and ScienceDirect blocked direct fetches; numbers from those are marked read_primary=false or taken from abstracts.","verification":{"date":"2026-10-29","method":"Adversarial check of 22 load-bearing claims: abstracts via Europe PMC REST and Crossref for every paper DOI (33/33 papers resolve to the stated title/authors/venue); full text of the ISS ICES-2026-425 PDF; WebFetch of NASA, MIT News, UC News, SJV Water, AgNavigator, Daily Galaxy, Technical.ly, WOTA, Hydraloop, Uravu, Watergen, SolarDew, Vuna, Eawag, Wikipedia (desalination) and the PoliTo patent. Arithmetic of N28-N30, rain/dew/pumping formulas and all three sizing_reference cases recomputed and correct. All source ids referenced exist; no orphan sources.","checked":22,"confirmed":14,"confirmed_items":["N01 98% / 93-94% before BPA / 2 lb per 100 lb (NASA)","N02 UPA 85->75% (2009)->85% (2016 phosphate)->87%, target 90%, Russian 70% (ICES-2026-425)","N03 17,900 L WPA Feb 2024-Feb 2026","BPA 780 of 946 L, 81 cycles; Sabatier offline since Oct 2017; UWMS stand-down from failed dose pump","N04 about 1 gal/person/day","N06 Lord 2021 0.2-2.5 L/kWh, 5 L/p/d, ~1 billion people","N07 Fathieh 2018 100 g/kg/day Arizona, 1.2 kg MOF-801","N09 Hanikel 2019 1.3 / 0.7 L/kg/day","N10 Almassad 3.5 L/kg/day, 1.67-5.25 kWh/L","N11 Li 2024 0.46-1.5 L/kWh, 0.66-2 L/day per m2 PV","N13 Klemm 3-10 L/m2/day","N14 SWRO 3-5.5 kWh/m3, minimum ~1 kWh/m3","N17-N23 Hydraloop 95/45/720; Fountoulakis 87% COD 95->8 mg/L; Reynaert FPR<=2%; Zeeman 11 g N 1.0 g P, 7.6 g N 69%; Vuna 500 L/yr and full approval 2018; Fumasoli 71+13 W/cap; Gao 0.5-1.2 L/flush 34% vs 48% BMP","N24 SOURCE Allensworth ~42 panels ~1 gal/day; N27 Chu 3.58/1.95 kg/m2/h; Lin 2025 3060 g/day 1.13 kWh/kg; AirJoule Prime 2,000 L/day, GE Vernova 50-50 JV"],"corrected":[{"item":"P-ADAPTIVE-MOF outcome","was":"software control alone gave +169% yield","now":"+169% vs the best previously reported active device (different hardware); not an isolated software effect","source":"src-almassad-2022 (abstract via Europe PMC)"},{"item":"N12 context","was":"Patent example at 50 C regeneration, 100 m3/h air.","now":"Patent example assumes 45 C regeneration and 35 C condensation, 100 m3/h air (about 45 L/day over 8 h of solar heat); heat-source range stated 50-80 C.","source":"src-pat-polito"},{"item":"N26 unit","was":"L per MW heat per day","now":"L per MW per day; vendor page does not specify heat vs IT load","source":"src-uravu-site"},{"item":"N25 context","was":"20-ft unit, rollout targeted 2026.","now":"20-ft containerised unit; article of 21 Jan 2026 says commercial rollout aimed 'within the next year' (no fixed year).","source":"src-agnav-atoco"},{"item":"Waste-heat AWH option TRL/why","was":"PILOT 7: Industrial units being built and sold (AirJoule Prime, Uravu data-centre product); household integration unproven.","now":"PILOT 6: AirJoule Prime unveiled 2026 and 'still being refined' with two more units being built for demonstrations/customer trials; Uravu markets a data-centre product but no independent field data; household integration unproven.","source":"src-technically-airjoule"},{"item":"WOTA option name","was":"Greywater to potable appliance (WOTA Unit)","now":"Household wastewater regeneration appliance (WOTA Unit; potable status disputed)","source":"src-wota-site; src-dailygalaxy-wota"},{"item":"N16 context","was":"Make-up from filtered rainwater; TRL 6 passed 2025.","now":"Vendor figure, 'may vary with usage'. TRL 6 passed 2025 (press). Drinking-water make-up depends on a rainwater purification module still in development per Feb 2026 press; WOTA site claims WHO-guideline quality.","source":"src-wota-site; src-dailygalaxy-wota"},{"item":"ISS total loop option maturity","was":"COMMERCIAL","now":"PILOT (TRL 9 applies to the flight system only; no terrestrial product)","source":"src-ntrs-iss-2026"},{"item":"PA-zeeman-2008 finding","was":"New sanitation concept saves 200 MJ/person/year and recovers 0.14 kg P/person/year.","now":"New sanitation concept (UASB for black and grey water plus kitchen waste) saves 200 MJ/year vs conventional sanitation (abstract does not state per-person basis), recovers 0.14 kg P/p/year and yields 90 L of potentially reusable water.","source":"src-zeeman-2008 (abstract via Europe PMC)"},{"item":"P-ISS-WRS urine backlog","was":"300 L urine backlog","now":"about 300 L pretreated urine collected during downtime, subsequently all processed, none disposed","source":"src-ntrs-iss-2026"},{"item":"N08, N15 values","was":"0.285 / 5000","now":"up to 0.285 / up to 5000 (sources state maxima)","source":"src-uc-deathvalley; src-mit-pved-2024"}],"removed":[],"unverifiable":["P-SOURCE: Source Global company status in 2026 (site returned 429; serp budget exhausted). Status labelled 'shipped (2026 status unverified)'.","P-MELISSA: 2026 COSPAR abstract content (ADS page not retrievable); only title-level claim retained.","P-URAVU: amount and round of the July 2025 Enrission India Capital funding (article 403; headline only).","P-WOTA: whether WOTA Unit currently delivers potable water (vendor site says WHO-compliant; Feb 2026 press says drinking-water module still in development); Noto 2024 deployment not stated on the WOTA English site.","P-GENAQ, P-AQUARIA, P-SOLARDEW (output figures not published by vendors; SolarDew Republic Europe crowdfunding and 1 million people by 2035 target confirmed).","N05 UN 50-100 L/p/d read via Wikipedia, WHO 2020 primary not retrieved.","Hydraloop and Watergen corporate status (operating as of their 2026 sites; no financial filings checked)."],"verdict":"Substantially sound. Every paper DOI is real and every checked paper number matches its abstract or primary text; the ISS figures match the ICES-2026-425 PDF exactly. Problems found were overstatement rather than fabrication: an inflated attribution of the Almassad +169% to software alone, a TRL 7 for waste-heat AWH where the flagship unit is still a pilot, a 'greywater to potable' label for WOTA Unit that the latest press contradicts, COMMERCIAL maturity for ISS flight hardware that has no terrestrial product, and minor unit/basis slips (Uravu MW basis, PoliTo regeneration temperature, Zeeman 2008 per-person). All corrected in place; company statuses for Source Global and Uravu funding remain open."},"certification":[{"id":"C-W1","regime":"California Direct Potable Reuse (CCR 22, 64669.x)","jurisdiction":"California, USA","status":"in force since 2024-10-01","applies_to":"Municipal wastewater to a public water system; no household pathway","requirement":"20/14/15 log (virus/Giardia/Crypto) design, 16/10/11 floor at all times; >= 4 processes, 3 mechanisms (membrane, chemical, UV >= 300 mJ/cm2); continuous SCADA LRV tracking; T5 chief and T3 shift operators","implication_for_orijo":"Use it as the engineering benchmark for MIZU potable release (four barriers, fail-closed on the 16/10/11 floor), but do not claim regulatory potable reuse at home. Until a household path exists, L3 water = recycled non-potable + potable from rain/air/delivered water through a certified point-of-use train.","sources":["src-ca-dpr-page","src-ca-dpr-text"]},{"id":"C-W2","regime":"NSF/ANSI 350 onsite residential and commercial water reuse","jurisdiction":"USA/Canada (referenced by plumbing codes)","status":"in force; Hydraloop certified 350R","applies_to":"Greywater/wastewater reuse appliances for non-potable uses (toilet flushing, irrigation)","requirement":"Numeric effluent limits NOT retrieved (NSF pages 403); must be read from the standard before certification planning","implication_for_orijo":"The realistic first certification for MIZU-1 (non-potable mode); test duration and cost to be read from the standard.","sources":["src-hydraloop-site"]},{"id":"C-W3","regime":"WHO Potable reuse guidance (2017) and water safety plans","jurisdiction":"global guidance","status":"guidance","applies_to":"Drinking-water suppliers and regulators","requirement":"Risk-managed water safety plan, control measures, monitoring, public acceptance","implication_for_orijo":"Ship each MIZU with a machine-readable water safety plan; this is how WOTA-type claims (\"meets WHO guidelines\") should be evidenced.","sources":["src-who-potable-reuse-2017"]},{"id":"C-W4","regime":"EU Regulation 2020/741 minimum requirements for water reuse","jurisdiction":"EU","status":"applies from 2023-06-26","applies_to":"Treated urban wastewater for agricultural irrigation; member states may opt out","requirement":"Quality classes and validation monitoring (numeric limits not retrieved in this pass)","implication_for_orijo":"Farm-module irrigation with recycled water in the EU sits under this regime, not drinking-water law.","sources":["src-eu-reuse-2020-741"]}],"revision_log":[{"date":"2026-10-29","by":"gaps-2026-10-29","change":"Added certification paths, new sources/numbers/papers/projects from the completeness-critic pass; see research/v4/gaps-log.md"}]}