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Urine Separation - Opportunities for developing countries 1 UNESCO-IHE Institute for Water Education Owned by all UNESCO member states Every year 200 MSc degrees Currently 100 PhD students Tailor made training, online courses, curriculum development Research 2 Urine separation Part of Wastewater Design 3 Distribution volume and concentrations WATER 40000 30000 20000 10000 0 NUTRIENTS greywater urine faeces 6 K P N 5 COD kg/cap/year (L/cap/year) Volume (L/cap.year) Volume 50000 4 3 2 1 0 greywater urine faeces Motivations for urine separation Increase capacity of existing WWTPs Reduction water demand Prevention discharge large part of micropollutants Enable recycling before treatment Prevention pathogen mobilisation in onsite systems 5 Nutrients in urine Problem Nitrogen Phosphorus Opportunity eutrophication complete fertiliser Potassium Sulphur Calcium Magnesium Micronutrients benefit over artificial fertiliser Oil of the future 6 Technologies available Depends on goal! Nutrient removal Nutrient recovery Hygienisation Stabilisation; volume reduction 7 Urine change during storage Before storage Na opslag urea mg/l 7600 0 ammonium mg/l 480 8000 phosphate mg/l 740 540 magnesium mg/l 100 0 calcium mg/l 180 0 bicarbonate mg/l 0 3200 alkalinity mg/l 22 490 - 6.2 9.1 pH Urine change during storage Before storage After storage urea mg/l 7600 0 ammonium mg/l 480 8000 phosphate mg/l 740 540 magnesium mg/l 100 0 calcium mg/l 180 0 bicarbonate mg/l 0 3200 alkalinity mg/l 22 490 - 6.2 9.1 pH Hygienisation Storage! Prevent High pH dilution High ammonia concentration Temperature best kept > 20°C 10 Nutrient removal Standard removal techniques can be applied Nitrification / denitrification Phosphate removal 11 Nutrient recovery: struvite NH4+ + PO43- + Mg2+ → MgNH4PO4 Struvite precipitation applied full scale Japan, Canada, USA (Ostara) Netherlands: industrial WWT (potato) Nepal: with urine from UDD toilets CrystalGreenTM Several possibilities for SMEs STUN Project, Nepal – www.sandec.ch Most obvious benefit: stop mobility pathogens Drawings by Albert Oleja, Uganda Direct benefits, even without treatment Prevention leakage nutrients + pathogens to groundwater -> helps drinking water treatment! Makes urine available for clean and easy transport Enabling safe handling (dried faecal matter 80% volume reduction) Reduction pit emptying frequency 15 Conclusion Urine separation: benefits for centralised and decentralised systems Treatment urine: with standard techniques After hygienisation: direct use as fertiliser Direct benefits, even without treatment 16 Thank you for your attention 17 We know struvite precipitates spontaneously – can we also use it? Chemical contaminants in urine Heavy metals (Cu, Zn, Cr, Ni, Pb, Cd) Hormones (endocrine disrupters) and pharmaceuticals: Average of 64% of a substance ingested is excreted in the urine (Escher, 2007, p. 24) Better to recycle urine to arable land than to flush into recipient waters because: • Hormones and pharmaceuticals are degraded in natural environments with a diverse microbial activity • Urine is mixed into the active topsoil and retained for months (see Course 3 “Reuse of ecosan products in agriculture”) 19 What you excrete vs what you need Values are country-specific or diet-specific (treat as guideline only!) cap = capita = person 20 Visual evidence faeces & urine Maize (corn) urine none compost improved soil untreated soil after one week without water Source: GTZ presentations 21