Electrochemical Stripping to Recover Nitrogen from Urine

Electrochemical stripping, a novel extension of electrodialysis, was used to recover nitrogen from source-separated urine. Urine has high nitrogen concentrations, making it an ideal waste stream for nitrogen recovery. A three-chamber, two-membrane cell was used to measure efficiencies and barriers to nitrogen migration. In preliminary batch studies, half of the influent nitrogen was recovered as ammonium sulphate, which can be used as a fertilizer. Obstacles to nitrogen migration include the production of chloramines, which can be avoided by controlling electrode materials and operating voltage. This proof-of-concept study makes the way for more detailed investigations that will lead to process optimization for maximal nitrogen recovery efficiency.