Feasibility and Environmental Implications of Urine Utilization Technologies in the Developing World

Abstract

The recovery of nutrients from excreta is one approach to satisfy the currently unmet sanitation needs of the developing world while providing a sustainable source of nutrients for fertilizer. Utilizing source-separated urine, which contains the majority of nutrients and is significantly less dangerous to handle than feces, is an important aspect of nutrient recovery. While there is interest in applying urine utilization technologies in the developing world, there is not always emphasis environmental implications or on how methods would operate in different situations. In this thesis economic, logistic, scientific, and environmental criteria were created and used to judge four urine treatment methods: electrodialysis, ammonia stripping, struvite precipitation, and evaporation. Evaporation was selected as the most feasible and studied in the context of SOIL, an organization that provides urine-diverting dry toilets to households in urban areas of Haiti. This thesis found that treatment of the predicted urine production would require an unreasonable amount of space for an urban household. The treatment process is likely to significantly contribute to hygienization and possibly to degradation of micropollutants. Further research into the application of nutrient recovery from urine in the developing world is recommended.