The Recovery of a Sequencing Biofilm Batch Reactor-Anammox System: Performance, Metabolic Characteristics, and Microbial Community Analysis

The mainstream application of the anammox process is often hindered by its long recovery phase and instability under disturbance. In this study, a lab-scale anammox sequencing biofilm batch reactor (SBBR) was rapidly recovered within 85 days by gradually increasing the influent nitrogen concentration, and the total inorganic nitrogen (TIN) removal efficiency achieved 83.44 & PLUSMN; 0.03%. During the recovery process, the nitrogen removal rate (NRR) increased from 0.05 to 0.34 kg/(m(3)& BULL;d), with the nitrogen loading rate (NLR) changing from 0.08 to 0.40 kg/(m(3)& BULL;d) in the anammox system. The activities of hydrazine oxidase (HZO) in the biofilm also increased from 0.17 to 10.80 & mu;mol Cyt-c/(g VSS & BULL;s). Also, the dominant anammox genera in the biofilm were Candidatus Kuenenia and Candidatus Brocadia. The results of this study suggested that an SBBR-anammox system filled with a microbial carrier could facilitate the enrichment of anammox bacteria and contribute to performance recovery.

Automated summary

In this study, a lab-scale anammox sequencing biofilm batch reactor (SBBR) was rapidly recovered within 85 days by gradually increasing the influent nitrogen concentration, achieving a total inorganic nitrogen (TIN) removal efficiency of 83.44 ± 0.03%. During the recovery process, the nitrogen removal rate (NRR) increased from 0.05 to 0.34 kg/(m(3)·d), with the nitrogen loading rate (NLR) changing from 0.08 to 0.40 kg/(m(3)·d) in the anammox system. The activities of hydrazine oxidase (HZO) in the biofilm also increased from 0.17 to 10.80 μmol Cyt-c/(g VSS·s). The dominant anammox genera in the biofilm were Candidatus Kuenenia and Candidatus Brocadia. These results suggest that an SBBR-anammox system with a microbial carrier can enhance the enrichment of anammox bacteria and contribute to performance recovery.