[Environmental Factors Influence and Microbial Community Structure Analysis of Entrapped Anaerobic Ammonium Oxidizing Bacteria].

To solve the problems of a slow start, easy loss, and easily inhibited activity of the Anammox bacteria suspension culture, polyvinyl alcohol-polypropylene (PVA-PP) was used to prepare the Anammox immobilized filler. To improve the activity of Anammox bacteria and ensure stable operation of the reaction system, the effects of COD interference, change in pH value, and rotating speed on the nitrogen removal characteristics of the immobilized filler were determined in batch tests. Changes in the structure and diversity of the bacteria in the filler were analyzed by a high-throughput sequencing technique. The results showed that the activity of Anammox bacteria could recover to 100% on the 30th day, and the total nitrogen removal rate was 87.7% when the total nitrogen volume load (NLR) was 0.69 kg·(m·d) at the stage of 99 days. After 140 days of long-term operation, the total nitrogen removal rate (NRR) reached 1.83 kg·(m·d), which was 9.4 times the suspended sludge before immobilization. The diversity of the population was maintained in the inclusion carrier, and the effective enrichment of (AF375995.1), which performs anaerobic ammonia-oxidization, increased from 11.06% to 32.55%. The influence of COD interference and changes in the pH value of Anammox bacteria was significantly weakened, and the PVA-PP entrapped carrier could achieve the coupling removal of nitrogen by Anammox and denitrification. Appropriate external hydraulic disturbance would promote the Anammox reaction in immobilized systems.