Evaluation of neglected bio-wastes potential with food-energy-sanitation nexus

Abstract

Abstract The purpose of this study is to assess the quantity and characteristics of food wastes and human excreta generated from Jimma University with the food-energy-sanitation nexus approach. The focus of this study is on food wastes and human excreta generated by regular undergraduate students living and feeding in the university. The results of the study showed that the University has an annual production potential of over 680 tons of food wastes, 715 tons of fresh feces and over 8 million liters of urine. This enables each student to an annual potential production of 4 kg of N, 0.6 kg of P and 0.96 kg of K from excreta and 1.7 kg of N, 0.5 kg of P and 0.51 kg of K from food wastes. The University potentially produces about 110 tons of nitrogen and 22 tons of phosphorus per year. Both food wastes and feces generated from the University have the theoretical potential of 8568 GJ of energy. This is a huge resource to contribute to the increasing fertilizer and energy demands in the country/region while contributing to the reduction of associated sanitation problems. Currently, the University is trying to solve these issues, but the planned option is not sustainable and does not enable closed-loop nutrient circulations. The current study considered food waste and human excreta generated by regular undergraduate students. Further research is recommended to study factors influencing end-use food waste generation in order to reduce wasting of food contributing to food security. Assessment of solid wastes and grey wastewater is also recommended to provide a full picture of the wastes potentially generated from the university.