Selecting a context-appropriate combination of faecal sludge treatment technologies Government support 12
Socio-cultural acceptance 16
12
Chapters
To next step
Treatment option
Future treatment perspective
Sludge transfer
Potential enduse
Future enduse perspective
Transfer to enduse
Decision factor
4
Assessment of the initial situation
13
Legal and regulatory framework
ENABLING ENVIRONMENT
Financial 13 arrangements
12 Institutional arrangements
11 16.5
14
Skills and capacities Enabling environment
17.2.1
Collection & Transport practice 4 Interest for enduse/resource recovery 10 Biogas demand
Fertiliser/Soil amendment demand
Selection of the treatment options
Energy/Building material demand
5 16.5 Characterisation and quantification of sludge
Dewaterability of sludge: degree of stabilisation/digestion
3 5
6
Need for further digestion/stabilisation
Iterative process until optimal solution is obtained
Stabilised sludge
Solid-liquid separation
Dewaterability of sludge: sludge concentration
Stabilisation
2
6
High dilution, space limited, operator capacity available
Sludge concentrated or availability of space
Unplanted drying beds
5
5 Imhoff tank
Conditions for drying available
Dewatering/drying
6
Settling/ thickening tank
Digester
Sludge spreadable
7
Mechanical dewatering (e.g. filter press, centrifuge)
Availability of organic waste
Planted drying beds
Pathogen reduction
8
Mechanical/heat drying (e.g. pelletiser)
Potential endproducts Dry sludge
10
Vermicomposting/ Black Soldier flies Co-combustion
Humified sludge
10
Biomass
10
Biogas
10
Matching with financial, organisational and O&M realities O&M Requirements (e.g. available skills and operator capacity)
11
Market studies of endproducts
Compost
10
Energy
10
13 Financial comparison of options
Trade-off
Final choice of combination of technologies
Land availability, cost and characteristics
5
Building 10 material
Selection of treatment sites 14
11 Possible management schemes
5
5
Co-composting
5
Storage and 10 further drying
10
Onsite ABR (e.g.public latrines)
14.4