WANGJing,YANGYi,BAIWen-long,et al.Application of Multi-stage A/O and Ozonation Combined Process for Upgrading and Reconstruction of a Wastewater Treatment Plant to Class Quasi-Ⅲ Standard for Surface Water[J].China Water & Wastewater,2025,41(6):83-88.
Application of Multi-stage A/O and Ozonation Combined Process for Upgrading and Reconstruction of a Wastewater Treatment Plant to Class Quasi-Ⅲ Standard for Surface Water
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第6期
Page:
83-88
Column:
Date of publication:
2025-03-17
- Keywords:
- wastewater treatment plant; upgrading and reconstruction; ozonation; class quasi-Ⅲ standard for surface water
- Abstract:
- The original design scale of a wastewater treatment plant (WWTP) in Ordos City is 6.0×104 m?/d. The primary treatment process incorporates oxidation ditch, followed by secondary sedimentation tank, coagulation sedimentation tank, and sand filter. The effluent quality is designed to meet first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). Given that the receiving water body downstream of the WWTP serves as the drinking water source, it is imperative to upgrade the existing wastewater treatment process to ensure that the effluent quality meets the class quasi-Ⅲ standard specified in Environmental Quality Standards for Surface Water (GB 3838-2002). In accordance with the actual treatment capacity of the WWTP, the design capacity scale was adjusted to 4.5×104 m3/d. The existing oxidation ditch process was modified to the multi-stage A/O (A/A/O/A/O) system, and fillers were introduced into the primary-aeration tank to enhance treatment efficiency and improve resistance to shock loads in winter. Additionally, a new ozone contact tank was constructed for advanced treatment. Following the reconstruction, the system’s resistance to shock loads was significantly enhanced and the effluent quality was stable. The average concentrations of COD, NH3-N and TP in the effluent were 12.8 mg/L, 0.14 mg/L, and 0.08 mg/L, respectively, all of which were lower than the class Ⅲ limits specified in the surface water standard. Additionally, the average concentration of TN in the effluent was 9.4 mg/L, satisfying the requirements for both reclaimed water reuse and tailwater discharge.
Last Update:
2025-03-17