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Doulaye Koné

SANDEC / EAWAG – Switzerland

www.sandec.ch

kone@eawag.ch

Tel.+41 44 823 55 53

Faecal Sludge

Collection and transport technologies

Environmental sanitation planning and infrastructures in developing countries

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1. 70-100 % of cities and towns in developing

countries served by on-site sanitation (latrines

and septic tanks)

3. Lack of regulations, illegal

dumping and use of FS

untreated

2. All installations produce

FS to be collected

( trucks replacing sewer lines ?)

On-site sanitation = the hidden reality

Engineers’ thrusts and beliefs How to empty this pit ?

What happens next ?

Challenges: how to shift our mind set?

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Problems

Pit emptying and FS haulage

No access to pits Traffic congestion

The challenge

• Distance?

• Reuse potential?

• Humidity (hygienic quality)?

• Additional treatment

(storage)?

• Greywater collection

transportation and treatment?

• Quantity (size of

neighbourhood)?

• Business opportunity?

The challenge

Latrines emptying technology

How does latrines technologies

influence emptying technologies and performances ?

DRY PIT LATRINE

POUR FLUSH LATRINE

SUCKING FROM TOP LEAVES DENSE SLUDGE

WATER ADDED FROM TOP DOES NOT MIX

HAND STIRRING IS NOT EFFECTIVE

SUCKING FROM BOTTOM REMOVES SLUDGE FIRST

INJECTED WATER MIXES WITH SLUDGE

WATERTIGHT PIT BOTTOM MAKES SUCKING EASIER

Urine diverted latrine

Sludge composition - Flow Behaviour (Bösch & Schertenleib, 1985)

0

20

40

60

80

100

0 2 4 6 8 10 12

% Volatile (TVS)

% H

2O

1

2

3

4

Low -

Low- : Low

+

Med: m

ed +

High - : High +

1.low- viscosity zone

2.low- : low+ viscosity zone

3.med : med+ viscosity zone

4.high- : high+ viscosity zone

Faecal sludge viscosity

In the street

Manual emptying (70%)

Dupimg in the street,

Reuse in agriculture

Manual emptying where trucks cannot access/pump or households cannot pay the service

Photo: P. Blunier, 2004

Manual emptying where trucks cannot access/pump or households cannot pay the service

Transportation of manually-emptied solids and liquids

Collection of dried sludge

Locally manufactured emptying technology

Animal-cart transportation

Vacutug Specifications

• WEIGHT: 950 KG.

• SIZE : L 3900mm X W 1350-mm X H 2000 mm

• SPEED: 5 Km/hr

• ENGINE: Four stroke 8 HP HONDA models GX240 petrol engine with Electronic ignition.

• VACUUM PUMP

• TANK : 500 liters capacity

• CAPITAL COST of MARK II: USD$ 5,100 (excluding freight)

UN-Habitat Vacutug

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• A Vietnamese model

e.g. Haiphong: Tanks in narrowlanes accessible by small vehicles

TRACTOR TRAILED VACUUM TANKER

MICRAVAC

Imported cesspits trucks

• Expensive maintenance • Spare parts often lacking• Out of age• Not appropriate

Locally manufactured cesspits trucks

• Low-cost operation and maintenance

• Maintenance skills and spare parts available

Locally manufactured cesspits trucks