Evaluation of the application and operational performance of the modified multistage AO process in a sewage treatment plant

The multistage anoxic/oxic (AO) process is widely known for its effectiveness in wastewater treatment, serving as a core technology in numerous wastewater treatment facilities. Its application in the expansion project of the sewage treatment plant in Dongguan City is particularly noteworthy and merits further research into its performance. To validate its reliability, we conducted a monitoring experiment spanning over 200 days. The results revealed that under stringent operational conditions, the plant demonstrated significant stability in ensuring the effluent quality meets grade A standards. Additionally, its removal efficiency for various pollutants exceeds 90%, particularly outstanding in nitrogen and phosphorus reduction, even when the total phosphorus in the influent exceeded the standard by 2.6 times, the effluent remained stable. These compelling pieces of evidence highlight the superiority of the multistage AO process, positioning it as the preferred technology for widespread adoption in the expansion of wastewater treatment plants. This study can provide valuable insights for the construction of other sewage treatment plants.