Partial Nitrification Characteristics of an Immobilized Carrier in Municipal Wastewater under Low-Temperature Shock: The Role of the Nitrifying Bacterial Community Structure

To analyze the effects of nitrifying bacterial community structure on partial nitrification (PN) characteristics in a PN-immobilized carrier municipal wastewater under low-temperature shock, two carriers with different communities were investigated. The E1-immobilized contained high abundance ammonia-oxidizing bacteria (AOB; 38.59%), and E2-immobilized had low AOB 4.78%. results experiments dissolved oxygen (DO) concentrations showed that oxygen-limited environment inside immobilized carrier, generated by abundance, was critical for achieving PN. nitrite accumulation rate (NAR) decreased from 90.0–93.9% to 84.2–88.3% 86.0–90.4% 81.7–85.8% shock (the temperature suddenly 25 ± 1 °C 15 °C). decrease ammonia oxidation due activity led NAR. Moreover, NOB increased because destruction oxygen-limiting region abundance. Increasing could reduce adverse shock. this study can be used further develop immobilization technology efficient PN mainstream treatment.