Process Optimization for Sequential Recovery of N, P and K from Human Urine

Abstract

Human urine is considered as a potential source for nutrient source. In this paper we have presented a sequential two step process development for recovery of all three essential nutrient namely, nitrogen, phosphorus and potassium from human urine. In the first step the ammoniacal nitrogen was recovered by stripping process at a pH range of 10 -12, airflow rate of 2.5, 5 and 7.5L/min and temperature of 40ËšC and 50ËšC followed by precipitation of phosphorus and potassium recovery in the form of struvite precipitation in step two. The maximum ammonia recovered was 99.97% with the stripping condition of pH 12, temperature 50ËšC and air flow rate of 5.0L/min. The recovery phosphate and potassium ranges from 76-99.98% and 58-85.59% respectively. The precipitates characteristics were further analysed by EDX, SEM XRD and FTIR examination.