Transcript Document
Urine Separation
- Opportunities for developing countries
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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
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Urine separation
Part of Wastewater Design
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Distribution volume and concentrations
WATER
40000
30000
20000
10000
0
NUTRIENTS
greywater
urine
faeces
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K
P
N
5
COD
kg/cap/year
(L/cap/year)
Volume
(L/cap.year)
Volume
50000
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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
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Nutrients in urine
Problem
Nitrogen
Phosphorus
Opportunity
eutrophication
complete fertiliser
Potassium
Sulphur
Calcium
Magnesium
Micronutrients
benefit over
artificial fertiliser
Oil of the future
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Technologies available
Depends on goal!
Nutrient removal
Nutrient recovery
Hygienisation
Stabilisation; volume reduction
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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
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Nutrient removal
Standard removal techniques can be applied
Nitrification / denitrification
Phosphate removal
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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
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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
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Thank you for your attention
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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”)
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What you excrete vs what you need
Values are
country-specific
or diet-specific
(treat as
guideline only!)
cap = capita = person
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Visual evidence
faeces & urine
Maize (corn)
urine
none
compost
improved soil
untreated soil
after one week without water
Source: GTZ presentations
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