Modelling the benefits of urine diversion for resource recovery: a case study of Arba Minch, Ethiopia

Urine diversion provides a possibility of linking environmental sanitation and agricultural production. In order to support decision making with regard to the implementation of dry, urinediverting toilets (UDDT), material flow analysis (MFA) can represent a useful tool. This paper presents the use of a material flow analysis for water, sanitation and organic waste applied to the city of Arba Minch, Ethiopia. Mass flows as well as nitrogen and phosphorus flows are assessed. The results highlight the potential for reduced environmental pollution as well as the recovery of valuable nutrients through the application of urine and compost. Different implementation pathways are modelled including uncertainty analyses. The results show that the replacement of nitrogen and phosphorus fertiliser currently required within the system boundaries is possible at UDDT implementation rates between 20 and 50%. If more households are equipped with UDDTs, excess nutrients can be delivered to surrounding areas with higher farming intensities.