[Effect of Temperature on ANAMMOX Process in Sequencing Batch Biofilm Reactors: Nitrogen Removal Performance and Bacterial Community].

For the ambient and low-temperature operation of the anaerobic ammonium oxidation (ANAMMOX) process, sequence batch biofilm reactors (SBBR) with non-woven fabric and modified polyurethane foam as carriers, respectively, were used to treat nitrogenous wastewater. Nitrogen removal performances of both reactors were investigated while the temperature decreased from 35℃ to 15℃. When the nitrogen loading rate (NLR) was 110 mg·(L·d)-1, the average total nitrogen (TN) removal rate of the non-woven fabric reactor increased from 71.16% (35℃) to 76.19% (30℃) and then decreased to 61.11% (15℃). The average TN removal rate of the modified polyurethane foam reactor increased from 78.71% (35℃) to 81.75% (20℃) and then decreased to 75.68% (15℃). Compared with the non-woven fabric, the modified polyurethane foam provided a more stable nitrogen removal performance and could be used as the preferred carrier. High-throughput sequencing of the modified polyurethane foam biofilm indicated that Candidatus Kuenenia was the dominant ANAMMOX genus, with relative abundances of 8% (35℃), 5% (25℃), and 16% (15℃). Candidatus Kuenenia still grew and enriched at low temperatures. The decrease in temperature significantly affected the biofilm microbial community structure.