Capacity strengthening in sanitation : benefits of a long-term collaboration with a utility and research institute

Sanitation investments in Africa have largely failed to meet the Millennium Development Goals. Many, sewer-based wastewater treatment plants provide inadequate treatment, and faecal sludge from onsite treatment in urban areas is largely untreated. The National Office of Water and Sanitation in Burkina Faso and the Department of Water and Sanitation in Developing Countries in Switzerland are involved in a collaboration designed to increase institutional aptitude, and develop sustainable long-term wastewater and faecal sludge management solutions. The developed approach evaluates and fills gaps in existing infrastructure, operational ability, local knowledge, and institutional procedures. The continuous communication between the partners has resulted in a synergy and increased level of commitment. This paper presents results and future plans of this utility - research approach that has resulted in training and capacity development plans and a much greater understanding of sanitation management. The lessons learned are transferable to other countries, institutes and sectors

Use of chitosan and Moringa oleifera as conditioners for improved dewatering of faecal sludge

A pilot-scale dewatering research facility was built in Dar es Salaam, Tanzania, and was used to test chitosan and Moringa oleifera as conditioners to improve the dewatering of faecal sludge. Laboratory-scale jar tests were first conducted to determine optimal dosages for the conditioners in faecal sludge samples with varying total solids concentrations. The results for chitosan were 0.5-0.6 mL/gTS, and for Moringa oleifera 5-15mL/gTS. Based on these results, pilot-scale tests were conducted with chitosan, but the use of Moringa was ruled out as it was too resource intensive. Three loading cycles were conducted, and an average of 15.3% reduction in dewatering time was achieved. Based on the laboratory and pilot-scale tests, chitosan is recommended as a conditioner for improved FS dewatering performance. It could be employed at full-scale, but still requires jar tests to determine optimal dosing

Market driven approach for faecal sludge treatment products

Inadequate management and treatment of faecal sludge continues to pose risks for public and environmental health. Given the variability of faecal sludge and location-specific nature of solutions, it is difficult to decide on treatment objectives and performance goals for treatment. The Market Driven Approach was developed as a quantitative methodology to determine which faecal sludge treatment products have the highest market potential in a defined location. This methodology provides a way to compare treatment products based on their real value for resource recovery. This paper discusses the results and lessons learned from field-testing in five cities across Africa and South-East Asia

Technologies for sanitation: how to determine appropriate sludge treatment strategies in Vietnam

Developing appropriate technologies for the sanitation chain in low- and middle-income countries is crucial to protect public and environmental health. This includes treatment systems for the sludge produced in onsite and centralized systems (i.e., faecal and wastewater sludge). As the quantities and characteristics of sludge differ from city to city, this requires context-specific technologies. This case study was conducted to identify potential management strategies in five cities in Vietnam. The influence of the enabling environment, existing infrastructures, local sanitation practices and socioeconomic contexts on the selection of technology was assessed through literature reviews, household surveys and interviews. A checklist of influential aspects is presented to make best use of local opportunities and minimize the risks of technology failure. This approach is applicable to develop sludge management strategies in other cities

FAQ: faecal sludge quantification and characterization - field trial of methodology in Hanoi, Vietnam

Characterizing and quantifying faecal sludge (FS) at a city-wide scale in low- and middle-income countries is essential for designing and planning appropriate FS treatment facilities. However, there currently is no accurate methodology for the estimation of these values. The FAQ (faecal sludge quantification and characterization) study developed a methodology, and is validating it in Hanoi, Vietnam and Kampala, Uganda. The method utilizes spatially analysed demographic data as a predictor of FS characteristics. Extensive sampling has been conducted to field test the presented method. This paper presents results of collected and analysed secondary data, and preliminary results of the TS, VS, COD and SCOD concentrations from household septic tanks in Hanoi, which were on average 26,471, 19,395, 37,541 and 713 mg/L respectively, and ongoing data analysis is being conducted

Characterization of faecal sludge during dry and rainy seasons in Ouagadougou, Burkina Faso

Faecal sludge (FS) management is a challenging problem in low-income countries where large parts of the urban population rely on onsite sanitation systems. The design of treatment plants relies on accurate knowledge of FS characteristics, but this information is lacking. The goal of this study, conducted between December 2010 and September 2011, was to determine physical and chemical characteristics of raw FS from collection and transport trucks in 5 discharge sites in Ouagadougou. Over 100 samples directly collected during truck discharge were analysed. Analyses included suspended solids, volatile suspended solids, total solids, total volatile solids, sludge volume index, chemical oxygen demand, biological oxygen demand, and heavy metals. The FS characteristics were highly variable, but had similar characteristics for FS collected during the dry and rainy seasons and at different discharge sites. The type of onsite system had an influence on FS characteristics

Results from FaME (Faecal Management Enterprises) - can dried faecal sludge fuel the sanitation service chain?

In Sub-Saharan Africa, sanitation needs for the majority of the urban population are met by onsite sanitation technologies. Cities grapple with management of faecal sludge (FS) once these technologies become full, while at the same time the urban economy is resource intensive. The FaME (Faecal Management Enterprises) project addressed both of these issues by identifying untapped markets for FS treatment products. Industries have a high fuel demand and FaME demonstrated that dried FS could be used as a solid combustible in industrial kilns. Existing treatment technologies were adapted for fuel production, and its application was demonstrated in two pilot kilns. Historically used as a soil conditioner, processing of FS to a solid biofuel could provide higher revenues, thereby providing a financial incentive for stakeholders to enhance FS management service along the entire sanitation chain

SEEK (Sludge to Energy Enterprises in Kampala): co-processing faecal sludge for fuel production

The goal of this project was to improve the resource-recovery value of faecal sludge treatment products. A market assessment identified coffee husks, spent grain, and sawdust as optimal organic wastes to coprocess with faecal sludge to increase its fuel value. Drying times of faecal sludge to 90% solids were reduced by half with co-pelletizing with these organic wastes. Briquettes produced with char had comparable heating value, fuel performance, and emissions to charcoal briquettes currently being sold. Use of pellets as a fuel was tested in a gasifier and in several industrial clay kilns (after crushing). High ash content led to clinker formation in the gasifier, but performed well in kilns. The potential market for co-processed faecal sludge fuels is high in Kampala, Uganda, especially among industries, however, the market for pellets needs to be developed

Estimating safely managed sanitation in urban areas; lessons learned from a global implementation of excreta-flow diagrams

The urban population will rise to 6.7 billion by 2050. The United Nations has committed to provide everyone with safely managed sanitation, but there is limited understanding of the scale of the challenge. This paper describes a methodology for rapid assessment of sanitation in cities including a graphical representation (a shit-flow diagram or SFD) and reports on findings from implementation in 39 cities. The SFD provides high level information for planning purposes covering the entire sanitation system in a city. More than half of the human excreta produced in these cities is not safely managed. The most significant portions of the unsafely managed excreta are: (i) contents of pits and tanks which are not emptied and are overflowing, leaking, or discharging to the surrounding environment (14%); (ii) contents of pits and tanks which are emptied but not delivered to treatment (18%); (iii) fecal sludge and supernatant delivered to treatment but not treated (3%); (iv) wastewater in sewers not delivered to treatment (14%); and (v) wastewater delivered to treatment but not treated (6%). Many cities currently relying on onsite sanitation for safe storage, particularly in Africa, will need new strategies as populations grow. Containment systems that discharge to open drains are common in some Asian cities; these pose a public health risk. Dumping of excreta is widespread and there is a lack of realistic performance data on which estimates of the extent and effectiveness of treatment can be made. The SFD production process can be challenging due to a lack of data and low technical capacity in cities. There is often uncertainty over terminology and over the status of infrastructure. Formalizing definitions for the SFD preparation process was found to be useful in overcoming capacity constraints in cities. The SFD produces a credible snapshot of the sanitation situation in a city. The paper provides evidence of the urgent need for improved management and monitoring of urban sanitation in cities around the world and highlights the role of the SFD as a planning tool

Capital and Operating Costs of Full-Scale Fecal Sludge Management and Wastewater Treatment Systems in Dakar, Senegal

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