Hong Chen, Enzhe Yang, Zhi Tu, Hong Wang, Ke Liu, Jing Chen, Sha Wu, Zhe Kong, Eli Hendrik Sanjaya, Min Yang
The single-stage autotrophic nitrogen removal (ANR) process is impeded by a long start-up cycle and unstable operation performance. In this study, an airlift inner-circulation partition bioreactor (AIPBR) was operated continuously for 215 days to explore methods of strengthening the performance and stable operation of the single-stage ANR system. AIPBR start-up period took around 38 days, the total nitrogen removal efficiency was > 85% on day 35. With the decrease of hydraulic retention time and the increase of aeration rate, the nitrogen removal rate increased to 0.85 ± 0.02 kg-N/m3/day. The sludge morphology gradually changed into dark-red floc-coupled granular sludge. Nitrosomonas (9.95%) and Candidatus Brocadia (6.41%) were dominant in the sludge. During long-term operation, AIPBR achieved the dual inner circulation of sewage and sludge and then formed effective dissolved oxygen and sludge partitions to provide a suitable growth environment for various functional bacteria, promote synergy between them, and strengthen the ANR performance. © 2022
Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha, 410004, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; Chemistry Department, Universitas Negeri Malang, 65145, Indonesia
