WANGWei,DINGYong-wei,YOULan,et al.Impact of Rainfall on Operation of Wastewater Treatment Plants in Separate Sewer Systems[J].China Water & Wastewater,2025,41(1):9-15.
Impact of Rainfall on Operation of Wastewater Treatment Plants in Separate Sewer Systems
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第1期
Page:
9-15
Column:
Date of publication:
2025-01-01
- Keywords:
- separate system; low water level; rainfall; sewer network; process model; biological response
- Abstract:
- Rainfall?induced inflow and infiltration can cause a significant increase in the influent volume of wastewater treatment plants(WWTPs), and dilute the collected sewage of the drainage system, resulting in a decrease in pollutant concentrations at the plant, which in turn affects the efficiency of wastewater treatment. Research has revealed the impact of pipeline scouring on the concentration of pollutants such as COD and SS under different liquid level operating conditions of a separate sewer network. Under the condition of maintaining a constant liquid level in the pump station and pipeline, when the rainfall was between 5 mm and 10 mm, each 1 mm of rainfall corresponded to a water volume increase of 3% to 10%, and the greater the rainfall, the more significant the increase. Simulation results of wastewater treatment processes showed that during rainfall, the influent volume of the WWTP increased, the concentration of influent quality decreased, sludge was transferred to the secondary sedimentation tank, which in turn affected the effluent quality. As the influent volume increased, the effluent concentration of the WWTP showed an upward trend. Peak capacity analysis indicated that the AAO process system of the WWTP was more stable under rainfall conditions compared to the modified alternating process system.
Last Update:
2025-01-01