硝化作用强度对EBPR工艺运行效果的影响OA北大核心CSTPCD

[Objectives]The present study aimed to investigate the effect of nitrification intensity on enhanced biological phosphorus removal(EBPR)process performance.[Methods]Acclimation of EBPR sludge was firstly carried out in an anaerobic-aerobic sequencing batch reactor(SBR).The influent ammonia concentration was raised to 48 mg·L-1 and a comparative study was conducted on the nitrification intensity and phosphorus removal efficiency of EBPR system with or without nitrification inhibitors addition for the purpose of further analyzing the effect of nitrification intensity on the operational performance of EBPR process.In each of those operational phases,cyclic changes of phosphate,ammonia,nitrate,nitrite concentrations in the mixed liquor,glycogen and polyhydroxyalkanoate(PHA)contents in EBPR sludge were determined to analyze the effect of nitrification intensity on the metabolism of polyphosphate accumulating organisms(PAOs).[Results]When the influent ammonia concentration raised to 48 mg·L-1 and with allylthiourea eliminated,the nitrification rate of EBPR system rose to 1.45-1.80 mg·h-1·g-1 after 17 days of operation,and an unexpected phenomenon of aerobic phosphorus release occurred,leading to a substantial decrease in the phosphorus removal efficiency of the system.Metabolic abnormality also occurred in PAOs as indicated by a significant increase in the amount of glycogen degradation and synthesis and a significant decrease in the amount of PHA synthesis and degradation.However,EBPR performance was restored to the normal level within 24 h following re-supplementation of allylthiourea to the influent.[Conclusions]EBPR process performance was closely related to the nitrification intensity and aerobic phosphorus release occurred as nitrification rate rose up to a certain degree,leading to a significant decline in phosphorus removal efficiency of EBPR process.