Insights into the promotion of urine-diverting toilets based on the fertilizer efficiency of artificial phosphate ore recovered from source-separated urine

Abstract

To recover nutrients from urine, the urine-diverting toilets play crucial role in collecting source-separated urine. However, the effects of urine dilution on the efficiency of nutrient recovery and properties of final products have not yet been paid adequate attention. Herein, an Mg-air fuel cell was applied to recover artificial phosphate ore (APO) from artificial fresh urine (AFU) with different dilutions. The APO recovered from undiluted AFU possessed the highest content of slow-release fertilizers (90.23%) and total primary nutrients (35.39%), meeting the quality requirements of compound fertilizer. The results of cultivating vegetable in pot trial verified that the fertilizer efficiency of such APO was superior to that of other counterpart fertilizers. The economic feasibility evaluation revealed that a net profit of $2.58 was also obtained by treating 1 m3 of undiluted urine. The findings indicate that the waterless urinal is worthy of being promoted for nutrient recovery from fresh urine.