[Realization of Short-cut Nitrification in a CAST Process at High Temperature and Its Phosphorus Removal Performance].
Huan Jing Ke Xue
; 40(3): 1375-1381, 2019 Mar 08.
Article
em Zh
| MEDLINE
| ID: mdl-31087987
ABSTRACT
A synthetic wastewater was employed to investigate the realization of short-cut nitrification and its phosphorus removal performance in a CAST reactor operated at 22â, 25â, and 28â. The results showed that TN removal of the system was stable and higher than 80% at different temperatures, and NH4+-N removal performed well. When the temperature was at 22â and 25â, nitrite accumulation was not observed in the system and the phosphorus removal rate were 94.3% and 86.9%, respectively. When the temperature was increased to 28â, nitrite accumulation efficiency in the reactor reached 87.2%, implying the system achieved a stable short-cut nitrification. In addition, in the short-cut nitrification stage at high temperature (28â), the phosphorus release and uptake capacity of the system decreased. The anaerobic phosphorus release/COD consumption (P/C) ratio was much lower compared those at 22â and 25â. However, the phosphorus removal performance of the reactor did not deteriorate at this stage. The phosphorus removal rate was 68.9%, indicating that a sufficient carbon source in the influent could not only guarantee the removal of TN, but also detoxify NO2- to reduce its inhibitory effect on the phosphate accumulating organisms (PAOs). The batch tests of phosphorus uptake by the sludge under different temperature conditions revealed that O2, NO3-, and NO2- could all be used as electron acceptors for phosphorus uptake. The aerobic phosphorus uptake rate was higher than that with NO3- and NO2- as electron acceptors. The phosphorus uptake rates of O2 and NO3- as electron acceptors were also found to be negatively correlated with temperature.
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MEDLINE
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Zh
Ano de publicação:
2019
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Article