CHENHuang-jun,LIYi-ping,ZHOUYu-xuan,et al.Characteristics of Rainy-weather Overflow Pollution from Separate System in Illicit Connection[J].China Water & Wastewater,2023,39(19):116-124.
Characteristics of Rainy-weather Overflow Pollution from Separate System in Illicit Connection
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第19期
Page:
116-124
Column:
Date of publication:
2023-10-01
- Keywords:
- separate system; illicit connection between storm and sewage sewers; sewer overflow; pollution characteristics; particle size distribution; influencing factor
- Abstract:
- The sewer overflow of the separate system with mixing of the rainwater and sewage is an important source of black odor in urban water. In this study, sewer overflow from rainwater drains with mixed rain-sewage connection in the old urban area of Nanning City was sampled and monitored to explain the water quality changes of sewer overflow and particle size distribution, and to explore the influence of rainfall intensity, rainfall duration and previous dry time on particle size distribution of sewer overflow. The results showed that the concentrations of COD, NH3-N and TN in the overflow sewage were 4.7 times, 4.1 times and 6.4 times higher than the surface water quality standard Ⅴ class, and the pollutants concentration reached the peak within 10 minutes after the maximum rainfall intensity. The particulate matter of 10-125 μm was the most in overflow sewage, accounting for 60% of the total particles. Both rainfall runoff and pipe sediment contributed significantly to the sewer overflow, and the particulate matter of 4-63 μm in rainfall runoff accounts for 30% of the total particles, mainly contributing to the small particulate matter in overflow sewage. Particulate matter greater than 250 μm was mainly found in the pipeline sediments, mainly contributing to the large particulate matter in sewer overflow. Rainfall intensity could affect the particle size distribution in overflow sewage, and the particle volume fraction in the particle size range of 63-125 μm had a significant negative correlation with rainfall intensity (P<0.05).
Last Update:
2023-10-01