Material flow analysis as a tool for sustainable sanitation planning in developing countries: case study of Arba Minch, Ethiopia

摘要

Material Flow Analysis is a method that can be used to assess sanitation systems with regard tontheir environmental impacts. Modelling water and nutrients flows of the urban water, wastewaternand waste system can highlight risks for environmental pollution and can help evaluating thenpotential for linking sanitation with resource recovery and agricultural production. This studynpresents the results of an analysis of nitrogen and phosphorus flows of Arba Minch town in SouthnEthiopia. The current situation is modelled and possible scenarios for upgrading the town’snsanitation system are assessed. Two different scenarios for nutrient recovery are analysed.nScenario one includes co-composting municipal organic waste with faecal sludge from pit latrinesnand septic tanks as well as the use of compost in agriculture. The second scenario based onnurine-diversion toilets includes application of urine as fertiliser and composting of faecal matter.nIn order to allow for variations in the rate of adoption, the model can simulate varying degrees ofntechnology implementation. Thus, the impact of a step-wise or successive approach can benillustrated. The results show that significant amounts of plant nutrients can be provided by bothnoptions, co-composting and urine diversion.