The utilization of struvite produced from human urine in agriculture as a natural fertilizer : a review

Most of the nutrients in municipal wastewater originate from urine. Nevertheless, chemical fertilizers are commonly used in the agriculture instead of urine. There are some problems related to the direct utilization of urine, such as micropollutants present in urine, odour and storage of large volume of urine. In wastewater, phosphorus may contribute significantly to the pollution of the aquatic systems. Therefore, wastewater treatment techniques are mainly focusing on removing phosphorus. Phosphorus is collected in the sludge either by a chemical or by a biological process. With the growing concern of micropollutants present, which are in the sludge, the use of sludge in agriculture has been gradually decreasing. It means that the phosphorus content in sludge is not recycled efficiently whereas the use of limited mineral phosphorus resources is growing. To overcome these issues, urine could be collected separately and struvite could be produced. This may recover about 90% of phosphate in urine. In this paper, the use of human urine and struvite as a fertilizer in the agriculture and the production of struvite is discussed. Results showed that the struvite could be an effective natural fertilizer.