There is currently a lack of access to affordable sanitation in urban areas of Sub-Saharan Africa. This study evaluated the potential for resource recovery from innovative faecal sludge treatment processes to generate a profit that could help sustain the sanitation service chain. A total of 242 interviews were conducted in Accra, Ghana; Dakar, Senegal; and Kampala, Uganda to compare markets in different cultural and regional contexts. Products identified to have potential market value include dry sludge as a fuel for combustion, biogas from anaerobic digestion, protein derived from sludge processing as animal feed, sludge as a component in building materials, and sludge as a soil conditioner. The market demand and potential revenue varied from city to city based on factors such as sludge characteristics, existing markets, local and regional industrial sectors, subsidies, and locally available materials. Use as a soil conditioner, which has been the most common end use of treated sludge, was not as profitable as other end uses. These findings should help policy and decision makers of sanitation service provision to design financially viable management systems based on resource recovery options.

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A value proposition: resource recovery from faecal sludge—can it be the driver for improved sanitation?

https://www.dora.lib4ri.ch/eawag/islandora/object/eawag%3A16563/datastream/PDF2/Penn-2018-Review_of_synthetic_human_faeces-%28accepted_version%29.pdf

Review of synthetic human faeces and faecal sludge for sanitation and wastewater research.

Faecal sludge (FS), a product from on-site sanitation systems, poses a management challenge in densely populated urban slums of Sub-Saharan Africa (SSA). Currently, FS or its liquid fraction after dewatering is co-treated with sewage in conventional treatment plants. When dewatered, the solid stream is dried and stored further as the terminal treatment or is co-treated directly with organic solid wastes in composting or anaerobic digestion systems. To implement these, FS has to be collected and transported. Also, land is needed, but it is in most cases limited in slums or their vicinity. The collection and transport of FS from slums is costly due to lack of access, traffic congestion and long travel distances to treatment plants. Moreover, uncollected FS poses health risks and pollutes surface and/or ground water within slums. This review demonstrates that currently utilized technologies and practices fall short in various ways and discusses the possibility of minimizing FS management related costs, risks and pollution in urban slums by decentralized treatment and end-use. It also discusses the possible FS-derived end-products and their benefits to urban slum dwellers. Substitution of a part of natural materials (sand and clay) when building and/or biomass (firewood and charcoal) for cooking with FS derived end-products could multiply the benefits of improved sanitation to slum dwellers.

/pdf/decentralized-options-for-faecal-sludge-management-in-urban-36o6whaduk.pdf

Decentralized options for faecal sludge management in urban slum areas of Sub-Saharan Africa: A review of technologies, practices and end-uses

Energy recovery from human faeces via gasification: A thermodynamic equilibrium modelling approach.

Reference EPFL-ARTICLE-202332doi:10.1021/es501645dView record in Web of Science Record created on 2014-10-23, modified on 2016-08-09

/pdf/looking-beyond-technology-an-integrated-approach-to-water-5goodee1fb.pdf

Looking beyond technology: an integrated approach to water, sanitation and hygiene in low income countries.

This research tested the viability of using faecal sludge (FS) as solid fuel – an end use that could unlock an environmentally and financially beneficial replacement for disposal-oriented FS management, while replacing fossil energy. FS samples were collected from pit latrines, septic tanks, drying beds and stabilization ponds in three cities, Kumasi, Dakar and Kampala. For each sample, the average calorific value, solids and water content, and their variation with source and age were determined. The average calorific value of untreated FS across the three cities was 17.3 MJ/kg total solids (TS), which compares well with other biomass fuels. The age of FS did not affect its calorific value, nor did the reduction in chemical oxygen demand (COD) that occurred while it was in drying beds. The TS content of FS depended on its source but ranged from 1 to 6% for sludge from septic tanks and pit latrines, respectively. Harnessing net energy from FS requires partial drying. The results indicate that sufficient drying occurs within two weeks in open-air drying beds, or in a matter of days with simple drying bed innovations.

/pdf/fuel-potential-of-faecal-sludge-calorific-value-results-from-374lqk5v2p.pdf

J. Kang

Papers

Fuel potential of faecal sludge: calorific value results from Uganda, Ghana and Senegal