| The performance of simultaneous nitrogen and phosphorus removal with an inner loop sequencing batch reactor were investigated by simulated municipal wastewater. The experimental results showed that COD, NH+4-N, and TP can be removed efficiently after four hours aeration, during which dissolved oxygen concentration was at 6mg/L at the beginning of aerobic phase and pH was in the rang of 7～8.The COD and NH+4-N as well as TP concentration in the effluent were about at 4～48 mg·L-1,0～2.0 mg·L-1, and 0～1.4 mg·L-1 respectively, which indicated the removal rate for each item were about 89.7%±6.5%,97.4%±3.6%,95.6 %±4.4% when the concentration of influent were about 170～260 mg·L-1, 20～30 mg·L-1, 8～20 mg·L-1,respectively.The removal rate of TIN(NH+4-N+NO-3-N+NO-2-N) was also reached about 70%. It was found during the research process that phosphorus removal can be achieved without anaerobic phase, which was conventionally considered as a key phase for phosphorus removal，and this phenomena can not be explained by traditional theory. |
