Optimizing Fertilizing Characteristics of Stored Human Urine

Because of the high concentration of nutrients in human urine, its utilization as an organic fertilizer has been notable throughout history. However, the nitrogen compounds in urine are not stable. Therefore, to convert urine into a suitable fertilizer, it is important to stabilize and adjust unstable nitrogen compounds such as ammonia. Because nitrification can influence the nitrogen profile, the use of nitrifying microorganisms can be useful for stabilizing the nitrogen profile of urine. In this study, we investigated the changes in nitrogen compounds in pure urine and examined the effect of adding Nitrosomonas Europaea bio-seed solution on these changes. We found that the addition of bio-seed could reduce nitrogen loss as well as the time required to stabilize nitrogen profile. Furthermore, we determined the optimum concentration of bio-seed (6 × 10 N. Europaea cells/L) that not only leads to the least nutrient loss but also results in the adequate nitrate : ammonium ratio and regulates the amount of nitrate produced, thereby preventing over-fertilization. At this concentration, no dilution or dewatering is required, thus, minimizing water and energy consumption. Usage of optimum of concentration of bio-seed will also eliminate the need for inorganic chemical additives.