waste to fertilizer: a dream to come true for sub-saharan africa!

WASTE TO FERTILIZER

Josiane Nikiema, Olufunke Cofie and the IWMI RQ team

A dream to come true for Sub-Saharan Africa!

Contacts: j.nikiema@cgiar.org or iwmi@cgiar.org

OUTLINE

A. DAILY FERTILIZER POTENTIAL

FOR 200,000 PEOPLE100 MT of municipal solid wastes (MSW)

50 MT of inorg. wastes

50 MT of org. wastes 6-12 MT of biochar

15 MT of compost

0.6-1.2 ha of land

1.5 ha of land

100 m3 of fecal sludge (FS)

Land application

Composting 1.5 MT of compost

4 MT of co-compost

0.7 ha of Land

0.5 ha of land (maize)

1.3 ha of land (maize)

Biochar 1 MT of biochar 0.2 ha of land

EXAMPLE: CROP YIELDS AND IMPACT ON INCOME

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Sheshegu Tuu-tengle Sheshegu Tuu-tengle

Yie

ld in

MT/

ha

Control

Farm 1

Farm 2

Farm 3

MAIZE

SORGHUM

($/ha) Users Non-users

Total fixed costs 191 137

Total variable costs 314 323

Revenues 919 606

Net Income 414 146

Location: Krobo

DAILY FERTILIZER POTENTIAL

FOR 200,000 PEOPLE270 m3 of urine

Direct land application

StruviteN:P:K:Mg of 6:29:0:10 Slow release fertilizer, suitable for plants or to

supplement other minerals

11 ha of Land

27 MT of excreta

Co-composting

Biochar

4-9 ha of Land

3-6 MT of biochar

13-26 MT of (co-)compost

0.3-0.6 ha of Land

80% of the nutrients needed to grow food for

the same population size

B. REUSE OPTIONS TESTED

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Crop type Non fertilized

Urine fertilized

Chemically fertilized

Country

Cabbage 19.5 32 31.0 Togo Cassava 45 60 60.0 Ivory

CoastCotton 0.18 0.35 0.38 MaliCorn 2.4 3.6 3.5 BeninEgg plant 2.8 16.0 17.1 Burkina

FasoLettuce 6.8 15.7 13.3 TogoOkra 1.7 2.3 2.6 Burkina

FasoSorghum 2.3 3.8 4.1 Burkina

FasoTomato 2.1 5.2 5.8 Burkina

FasoYam 4.0 8.0 6.0 Ivory

Coast

Crop Yields (Tons ha-1) for urine trials in different

West African countries. (CREPA, 2006)

2. ORGANIC SOLID WASTE

• Compared to Africa, Asia is more advanced

– E.g. Sri Lanka has 115 municipal solid waste (MSW) compost plants

– A2Z in Ludhiana (India) processes 900 MT/d of MSW through

– These plants are either fully publicly owned or managed under a PPP

Examples of Kenyan compost plants

Dudutech4 MT/d

EcoHHoldings 550 MT/d

Nawacom Coop. Society

28 MT/ d

Uga

nd

a; 6

0

MT/

d Ghana; 600 MT/d

And more large MSW compost plants…

Composting is common because it reducesvolumes of wastes and need for landfills

3. THE STORY IS QUITE DIFFERENT WITH EXCRETA

•

• Few exceptions processing some MT per day are:

Sanergy, KenyaSoil – Haiti

NGOs

Burkina Faso

Rwanda

KenyaSouth Africa

Etc.

Safisana compost Uses digested (sludge + org. wastes)

Loowatt, Madagascar

4. THE STORY IS WORSE WITH FECAL SLUDGE

FORTIFER (Wafo) In Ghana Senegal

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C. THERE IS OPPORTUNITY FOR SCALING UP

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NutrientsOrganic matter

Improvessoil quality

Improve crop yields

D. WHAT IS NEEDED FOR SUCCESSFUL SCALING-UP?

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ON THE GROUND, WE ALSO NEED TO:

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RECYCLING OF WASTE INTO FERTILIZER WILL THEN BECOME A FACT FOR

SUB-SAHARAN AFRICA

Compost

• Biochar

Direct land application

(Co-)compost

• Biochar

Direct application

• Struvite: MgNH4PO4.6H2O

Compost

• Dry soil conditioner

• Biochar