Nitrification of human urine for its stabilization and nutrient recycling

Nitrification of human urine performed for its stabilization, and culture of Spirulina platensis in the nitrified human urine were investigated for nutrient recovery. With daily adjusting to pH 8 and keeping high dissolved oxygen concentration, mean 95.0% of NH4-N in human urine can be finally stabilized and oxidized to NO3-N. Furthermore, this nitrified human urine seems to be an ideal culture medium for S. platensis. Without pH adjustment, only about 50.0% NH4-N could be converted, i.e. NH4NO3 would be formed. Under low dissolved oxygen concentration, mainly short nitrification (from NH4-N to NO2-N) occurred.