An integrated ecological sanitation framework for water consumption reduction and energy generation, Capricorn District, Limpopo province, South Africa

Abstract

Ecological sanitation is a systematic approach whose aim is to safely close the loop for nutrients and organic matter. The 6th Sustainable Development Goal focuses on the need to ensure sustainable management of water and sanitation. This study was designed to develop an integrated Ecological sanitation framework for water consumption reduction and energy generation. The research was conducted to explore the implementation of Ecological sanitation framework and water consumption reduction using self-administered surveys and observations at 108 schools within the Capricorn District, Limpopo province in South Africa. Results revealed a significant association between the duration of Ecological Ventilated Improved Pit (EVIP) toilet use and the toilets' condition with a χ2(df = 9, n = 107) = 19.004, p = .025. The study showed that 78.7 % of the respondents did not think that human waste can be a beneficial resource, hence 99.1 % of the schools are not reusing the waste. In addition, 66.5 % of the respondents indicated that they will never consume crops that used composted human excrement. However, a positive association (χ2(df=3, n = 108) = 26.243, p = .000) between the number of toilets and reuse of human waste compost suggested that the component of user sustainability in terms of the beneficial concepts will complete the sanitation system cycle. This positive association entails a successful implementation because when concepts are better known, the ideas are better accepted. In terms of water consumption, results showed that before the implementation of EVIP, overall, the schools used an average of 1 231 litres per day. However, upon the implementation of EVIP toilets, a dry sanitation system, an average of 338 litres was used daily, translating into 893 litres of water saved per day (73 %). In addition, the biochemical methane potential (BMP) test was used to estimate the amount of energy that can be produced from human faeces collected from the EVIP. Optimal volatile solids of human faeces were recorded at 82. 7 %, total solids at 28.5 %, moisture content at 71.5 % while the pH was 6.4. After anaerobic digestion of human faeces, volatile solid reduction was found to be 48. 4 % while the pH decreased to 6.2. Accumulated biogas production from 25 g of faeces was recorded at 0,00528 m3 after 69 days of incubation, translating to 0.000346 m3 maximum production per day and a methane content of 54 %. The total biogas produced by the 483 learners was 66,62 m3. Overall, the experiment showed that the total energy produced could be used to prepare meals for the school feeding schemes and provide lighting to the school. This was based on the observation that 2 m3 of biogas can be used to cook for approximately 1 hour while 1 m3 of biogas can operate a 60-100 W bulb for six hours. The conceptual framework of the study recommends imparting knowledge on perceived benefits, implementing supportive regulations, enforcing monitoring and evaluation tools for proper management and compliance, and initiating incentives can collectively contribute to effective implementation of the EVIP.