Pilot study on optimization of multistage AO process based on enhanced denitrification

作者：WU Yahui, Pan Yang · 发表于：DOAJ (DOAJ: Directory of Open Access Journals) · 年份：2025 · DOI：10.19965/j.cnki.iwt.2024-0623 · 研究领域：Wastewater Treatment and Nitrogen Removal、Constructed Wetlands for Wastewater Treatment、Water Quality Monitoring and Analysis

Under the condition of no carbon source dosing,a multistage AO process with segmented reflux was used to treat municipal wastewater,and the process parameters were optimized by means of the simulated anoxic tank denitrification pilot test and analysis of the oxidation reduction potential(ORP) of the anoxic tank. The results showed that after the process optimization,under the parameters of internal reflux ratio(50%,50%), influent distribution ratio(7∶3) and DO(0.3 mg/L, 1.5 mg/L) of the primary/secondary aerobic tank(O1/O2), the effluent met the requirements of “Suzhou special emission limit”(TN 6-9 mg/L) and operated with low carbon. The denitrification microenvironment of process A1/A2 was good, with ORP of -30, -15 mV, respectively, and obvious simultaneous nitrification and denitrification was found in O1/O2. The dominant bacteria in the system are norank_ f_ saprospiraceae, Dokdonella, Trichococcus, and the relative abundance of denitrifying bacteria increased from 21.48% to 51.82%. Compared with other upgrading and reconstruction processes, this process had low energy consumption and had advantages in reducing pollution and carbon.