Characteristics of Nitrification and Denitrification for Simultaneous Nitrogen and Phosphorus Removal by Granular Sludge

In the alternating anaerobic /aerobic SBR reactor,the nitrification and denitrification characteristics of simultaneous nitrogen and phosphorus removal by granular sludge were studied. The results of batch experiments indicated that the maximal nitrification rate, denitrification rate,anoxic phosphorus uptake and denitrification rate were 14. 13 mg·( g·h)- 1,34. 89 mg·( g·h)- 1and 13. 11 mg·( g·h)- 1,respectively. In SBR,the maximal nitrification rate and denitrification rate were 4. 60 mg·( g·h)- 1and 1. 43 mg·( g·h)- 1,respectively,which were lower than those in the batch test. The amount of nitrogen removal by the simultaneous nitrification and denitrification process was approximately 232. 5 mg·d- 1,which was 54. 3% of the total nitrogen removal. The removal efficiency of N and P was about 90% and 95%,respectively. The simultaneous nitrogen and phosphorus removal by granular sludge showed high efficiency in nitrogen and phosphorus removal.