Transcript Document

Urine Separation
- Opportunities for developing countries
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UNESCO-IHE
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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
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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!
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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
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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
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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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