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

0

10000

20000

30000

40000

50000

greywater urine faeces

Volum

e (L/

cap/

year

)

WATER

Vol

ume

(L/c

ap.

yea

r)

0123456

greywater urine faeces

kg/c

ap/y

ear

KPN

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

Problem Opportunity

Nitrogen eutrophication

Phosphorus complete fertiliser

Potassium

Sulphur

Calcium

Magnesium

Micronutrients benefit 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 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

pH - 6.2 9.1

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

pH - 6.2 9.1

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

NH4+ + PO4

3- + 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

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 water Maize (corn)

Source: GTZ presentations