Study of the Characteristics of Denitrification Phosphorus Removal Using Nitrite as Electron Acceptor

A SBR process was adopted to investigate the characteristics of denitrification phosphorus removal by using nitrite as electron acceptor and treating real domestic wastewater.An anaerobic/anoxic method was introduced in the process,and nitrite was dosed at the end of anaerobic phase.According to the different level of influent COD and the dosed nitrite,the experiment can be separated into three phases.At the third phase,keeping nitrite at 20 mg/L,after a long tern domestication,the max phosphorus uptake rate raised to 11.70 mg/(gMLSS·h) in the anoxic phase,and 74.7% of released phosphorus was up-taken,while the 57.8% of phosphorus was removed from the system.Taking a shock load experiment by raising the initial concentration of nitrite to 50 mg/L,the max phosphorus uptake rate was only 5.63 mg/(gMLSS·h),decreased 53% compared with the third phase.By investigating the impact of different electron acceptor(NO₃^--N、O₂) to the system,the max phosphorus uptake rate was 11.09 and 29.268 mg/(gMLSS·h) respectively,which was 94.7% and 2.5 times of the third phase.