Xiaoting Xiong, Jingyi Jiang, Hanbo Yu, Yanxiao Wei, Jing Chen, Zhihua Liu, Haoshuai Ji, Hong Chen, Eli Hendrik Sanjaya, Lvzhou Wu
To maintain the long-term stability and efficiency of the partial nitritation/anammox (PN/A) process, a novel partition bioreactor featuring a uniquely sieve plate was developed to improve the airlift inner-circulation. The bioreactor achieved startup within 38 days, effectively handling influent containing 150 mg-N/L ammonium nitrogen and 50 mg-N/L nitrite. By reducing hydraulic retention time, nitrogen loading rate was escalated to 0.60 kg-N/m3/d, maintaining over 80 % nitrogen removal. Additionally, fluctuations in nitrite-oxidizing bacteria (NOB) were automatically controlled through dissolved oxygen (DO) partitioning. Moreover, the average granules size expanded from 85 μm to 338 μm by day 127, coinciding with robust anammox activity reaching 1.02 ± 0.05 g-N/g-VSS/d by day 179. The results demonstrate that the bioreactor effectively enhanced the enrichment of functional bacteria, enabled spatial distribution of DO, promoted NOB self-regulation and sludge granulation. This approach provides an efficient solution for rapid granulation while maintaining stable performance in the PN/A process. © 2025
Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China; Fujian Strait Graphene Industrial Technology Research Institute, Jinjiang, 362200, China; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Kanagawa, Yokohama, 230-0045, Japan; Chemistry Department, Universitas Negeri, Malang, 65145, Indonesia
