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Sonko E.H.M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Sonko E.H.M.,Cheikh Anta Diop University | Diop C.,Cheikh Anta Diop University | Mbeguere M.,Office National de lAssainissement du Senegal | And 3 more authors.
Journal of Water Sanitation and Hygiene for Development | Year: 2015

To optimize faecal sludge (FS) treatment plants in operation in Dakar (Senegal), this study was conducted to test the effectiveness of the solid/liquid separation on unplanted drying beds under different loading rates and two operation strategies (one or two feedings per campaign). Clogging, purification performances, dryness and hygienic quality were monitored. Results have shown that the load fractionation has reduced the clogging. Only removals of total solids (TS) and slightly those of total Kjeldahl nitrogen and chemical oxygen demand are influenced by the loading rate and the feeding mode. The reduction of faecal coliforms (FC) and helminth eggs (HE) in leachates is, respectively, 1 log unit and 100%. Two to nine days were sufficient to obtain a dryness higher than 80% TS with nominal loads of 13.7–122 kg/m2*year. Concentrations of the dried sludge in FC and HE were, respectively, about 7.104 FCU/100 g and 46 eggs/g with a reduction of 3 log unit after 15 days of drying and 32% in the sludge stored during 30 days. Unplanted beds are not effective for the treatment of low concentrated FS. The use of other technologies such as planted drying beds could be advisable in these types of sludge. © IWA Publishing 2015.


Bassan M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Kone D.,Bill and Melinda Gates Foundation | Mbeguere M.,Office National de lAssainissement du Senegal | Holliger C.,Ecole Polytechnique Federale de Lausanne | Strande L.,Eawag - Swiss Federal Institute of Aquatic Science and Technology
Journal of Environmental Planning and Management | Year: 2015

Many factors influence success and failure of large-scale faecal sludge and wastewater treatment projects in low-income countries. Benchmarking indicators and multicriteria analysis were adapted to define key institutional, technical and financial factors, to analyse their interrelations, and understand priorities to consider when planning and managing treatment plants. For the first time, these methods have been combined in a quantitative manner to assess planned and on-going treatment plant projects. This new methodology will aid sanitation utilities, private consultants, and funding institutions to prioritise activities and organise the operation of treatment plants. © 2014 University of Newcastle upon Tyne.


Dodane P.-H.,Toilettes du Monde | Mbeguere M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Sow O.,Office National de lAssainissement du Senegal | Strande L.,Eawag - Swiss Federal Institute of Aquatic Science and Technology
Environmental Science and Technology | Year: 2012

A financial comparison of a parallel sewer based (SB) system with activated sludge, and a fecal sludge management (FSM) system with onsite septic tanks, collection and transport (C&T) trucks, and drying beds was conducted. The annualized capital for the SB ($42.66 capita-1 year -1) was ten times higher than the FSM ($4.05 capita -1 year-1), the annual operating cost for the SB ($11.98 capita-1 year-1) was 1.5 times higher than the FSM ($7.58 capita-1 year-1), and the combined capital and operating for the SB ($54.64 capita-1 year -1) was five times higher than FSM ($11.63 capita-1 year-1). In Dakar, costs for SB are almost entirely borne by the sanitation utility, with only 6% of the annualized cost borne by users of the system. In addition to costing less overall, FSM operates with a different business model, with costs spread among households, private companies, and the utility. Hence, SB was 40 times more expensive to implement for the utility than FSM. However, the majority of FSM costs are borne at the household level and are inequitable. The results of the study illustrate that in low-income countries, vast improvements in sanitation can be affordable when employing FSM, whereas SB systems are prohibitively expensive. © 2012 American Chemical Society.


Bassan M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Mbeguere M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Tchonda T.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Zabsonre F.,Office National de lAssainissement du Senegal | Strande L.,Office National de lEau et de lAssainissement
Journal of Water Sanitation and Hygiene for Development | Year: 2013

The National Utility for Water and Sanitation in Burkina Faso (ONEA) has recognized the difficulty in providing sewered sanitation to the entire urban population and has opted for a strategy involving onsite sanitation. Most of the country's population is served by onsite systems that generate large amounts of faecal sludge, and are responsible for a high prevalence of water-borne diseases. ONEA and the Department of Water and Sanitation in Developing Countries (Sandec) at the Swiss Federal Institute of Aquatic Science and Technology (Eawag) have a collaborative project that aims to establish an enabling environment for the development of the faecal sludge sector at the institutional and technical level. The project's participatory process has allowed the design of a treatment plant adapted to local conditions, and the elaboration of the first institutional framework for faecal sludge management including several new official documents. Several technical studies filled knowledge gaps of faecal sludge characterization, and the feasibility of implementing planted drying beds. Lessons learned are transferable nationally and internationally. © IWA Publishing 2013.


Diener S.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Semiyaga S.,Makerere University | Niwagaba C.B.,Makerere University | Muspratt A.M.,Waste Enterprisers Ltd | And 5 more authors.
Resources, Conservation and Recycling | Year: 2014

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. © 2014 The Authors.

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