Recovery of minerals as value-added products from source-separated urine
The Aerosan Urine-Diverting Dry Toilet is a dry toilet with urine diversion that is designed to be deployed in the field for humanitarian aid and to provide safe and affordable sanitation in a variety of settings worldwide. This source-separated urine contains almost 80% of the nitrogen, 60% of the potassium and 55% of the phosphorus that humans excrete, and these are the main minerals required by plants. Therefore, extraction of these minerals in the form of struvite, which has commercial value as a solid, storable, slow-release fertilizer, would be one opportunity offered by this aspect of source-separated urine. Recovery of urea nutrients in the form of struvite pellets also prevents the breakdown of urea (ureolysis) and production of various ammonia compounds, which result in undesirable pungent odors. This project, will evaluate the effect of two different industrial struvite precipitants and the solution temperature and pH, on struvite precipitation.