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 COD WATER Volume (L/cap.year) NUTRIENTS

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

ProblemOpportunity Nitrogeneutrophication Phosphoruscomplete fertiliser Potassium Sulphur Calcium Magnesium Micronutrientsbenefit over artificial fertiliser Nutrients in urine 6 Oil of the future

Technologies available 7 Depends on goal!  Nutrient removal  Nutrient recovery  Hygienisation  Stabilisation; volume reduction

Before storageNa opslag ureamg/l76000 ammoniummg/l phosphatemg/l magnesiummg/l1000 calciummg/l1800 bicarbonatemg/l03200 alkalinitymg/l22490 pH Urine change during storage

Before storageAfter storage ureamg/l76000 ammoniummg/l phosphatemg/l magnesiummg/l1000 calciummg/l1800 bicarbonatemg/l03200 alkalinitymg/l22490 pH Urine change during storage

Hygienisation 10  Storage!  High pH  High ammonia concentration  Temperature best kept > 20°C Prevent dilution

Nutrient removal 11 Standard removal techniques can be applied  Nitrification / denitrification  Phosphate removal

Nutrient recovery: struvite NH PO Mg 2+ → MgNH 4 PO 4

Struvite precipitation applied full scale  Japan, Canada, USA (Ostara)  Netherlands: industrial WWT (potato)  Nepal: with urine from UDD toilets CrystalGreen TM Several possibilities for SMEs STUN Project, Nepal –

Most obvious benefit: stop mobility pathogens Drawings by Albert Oleja, Uganda

Direct benefits, even without treatment 15  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

Conclusion 16  Urine separation: benefits for centralised and decentralised systems  Treatment urine: with standard techniques  After hygienisation: direct use as fertiliser  Direct benefits, even without treatment

Thank you for your attention 17

We know struvite precipitates spontaneously – can we also use it?

19 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”)

20 Values are country-specific or diet-specific (treat as guideline only!) cap = capita = person What you excrete vs what you need

21 Visual evidence urinefaeces & urine none compost improved soil untreated soil after one week without waterMaize (corn) Source: GTZ presentations