不同厌氧时间对富集聚磷菌的SNDPR系统处理性能的影响

在延时厌氧(3h)/低氧(2.5h,溶解氧0.5~1.0mg/L)条件下运行的富集聚磷菌的同步硝化反硝化(SNDPR)系统中,以城市生活污水为处理对象,研究了不同厌氧时间(3.5,3,2,1.5h)对系统内碳源贮存以及脱氮除磷效果的影响.试验结果表明:厌氧时间为3.5h,反应器脱氮效果最好.厌氧时间为3h时,反应器除磷效果最好,出水PO₄^3-浓度为0.35mg/L.厌氧时间从1.5h逐渐上升到3.5h时,厌氧末贮存的聚羟基脂肪酸-PHAs的量也随之增加;当厌氧时间从3h升至3.5h时,释P量反而下降,出水P浓度反而升高.这说明增加厌氧时间有利于强化内碳源贮存,但过长的厌氧时间反而不利聚磷菌种群的富集.运行51个周期之后在厌氧时间为1.5h和2h的反应器内出现非丝状菌膨胀;反应周期内pH值的变化曲线可以作为反应各个过程的指示参数.

Effect of different anaerobic time on the nutrient removal in simultaneous nitrification-denitrification and phosphorus removal (SNDPR) systems enriched with phosphorus accumulating organisms

This study aimed to investigate the effect of different anaerobic time(3.5, 3, 2, 1.5h) on the nutrient removal and the intracellular carbon storage of simultaneous nitrification-denitrification and phosphorus removal (SNDPR) systems treating urban sewage. The SNDPR system was enriched with phosphorus accumulating organisms (PAOs) and operated under extended anaerobic (3h) and short low aerobic (2.5h, with dissolved oxygen concentration for 0.5~1.0mg/L). Experiment results showed that the system nitrogen and phosphorus removal perforamce improved with the extending anaerobic time. When the anaerobic time was 3h, the phosphorus release was best with the effluent concentration (0.35mg/L). When anaerobic time gradually increased from 1.5h to 3.5h, poly-hydroxyalkanoates (PHAs) synthetic amount increased, but phosphorus release amount decreased. The results indicated that extended anaerobic time (3h) was benifical for enhacing the intracellular carbon storage, but overlong anaerobic time (above 3.5h) was inimical to the dominant PAOs. Additionally, non-filamentous bulking appeared at the anaerobic time of 1.5h and 2h after 51cycles operation, and pH could be used as the indicating parameter for phosphorus realse, phosphorus uptake and simultaneous nitrification-denitrification in the SNDPR system.