Deciphering behaviors of 6:2 chlorinated polyfluorinated ether sulfonate (alternative-PFOS) on anammox processes: Nitrogen removal efficiency and microbial adaptability.

[Display omitted] • 0.5 mg·L−1 of F-53B had no noticeable effect on nitrogen removal performance. • Microbial defluorination was feasible in the anammox process. • Denitratisoma was the dominant bacterial genus (40.7 %) at 0.5 mg·L−1F-53B. • The relative content of H 2 O 2 decreased by 26.1 % with the introduced 0.5 mg·L−1F-53B. • F-53B inhibited ammonium transport by binding to Amt domain. This study investigates the behaviors and effects of F-53B, an alternative to perfluorooctane sulfonate on anaerobic ammonium oxidation (anammox) processes. Results showed that the nitrogen removal efficiency (NRE) reached 83.8 % at a F-53B concentration of 0.5 mg·L−1, while NRE decreased to 66.9 % with 5 mg·L−1 of F-53B. The defluorination rates of 17.8 % (0.5 mg·L−1) and 9.3 % (5 mg·L−1) were observed, respectively, suggesting the occurrence of F-53B degradation. The relative abundance of Ca. Kuenenia decreased from 26.1 % to 16.2 % with the F-53B concentration increasing from 0.5 mg·L−1 to 5 mg·L−1. Meanwhile, Denitratisoma was selectively enriched with a relative abundance of 40.7 % at an F-53B concentration of 0.5 mg·L−1. Ca. Kuenenia could reduce reactive oxygen species induced by F-53B to maintain the balance of oxidative stress. This study gains insight into the behaviors and metabolic mechanisms of F-53B in anammox consortia, suggesting the feasibility of anammox processes for industrial wastewater. [ABSTRACT FROM AUTHOR]