Chinese Journal of Chemical Engineering ›› 2012, Vol. 20 ›› Issue (4): 747-753.
刘巍1; 杨殿海1; 徐立1; 贾川1; 卢文建1; BOSIRE O.I.2; 沈昌明1
LIU Wei1; YANG Dianhai1; XU Li1; JIA Chuan1; LU Wenjian1; BOSIRE O.I.2; SHEN Changming1
摘要: A pilot-scale, pre-anoxic-anaerobic oxidation ditch was used in this study to treat municipal wastewater with limited carbon source. A novel return activated sludge (RAS) pre-concentration tank was adopted for improving the phosphorus removal efficiency and the effects of RAS pre-concentration ratio were studied. Under the optimal operational condition, the suspended total phosphorus (STP) and the total phosphorus (TP) removal efficiencies were around 58.9% and 63.9% respectively and the effluent -P was lower than 0.8 mg•L?1. The reason is that with the optimal RAS pre-concentration ratio, nitrate is completely removed with endogenous carbon source and the secondary phosphorus release is strictly restrained in the pre-anoxic tank. Therefore, the anaerobic phosphorus release and the carbon source uptake by phosphorus accumulation organisms (PAOs) in the sludge, which are ex-tremely important to the phosphorus removal process, can be fully satisfied. Furthermore, the oxidation-reduction potential is proved to be suitable for controlling the RAS pre-concentration ratio due to influent fluctuation and varied conditions. The novel modified system is also beneficial for PAO accumulation.