Correlation between the Pollutant Content of Sewer Sediments and the Particle Size in Urban Drainage Pipelines

Accumulation of solids in storm sewers results in not only a loss of flow-carrying capacity, but also corrosion of drainage pipes and pollution of receiving water bodies. This paper presents the correlation of sewer sediments' particle size with content of organic matter, total phosphorus (TP) and total nitrogen (TN) respectively in an urban area of Guangzhou. The result shows that the sediments of the researched areas can be divided into two types. Type One mainly consists of gravel, sand, and a little decayed animal matter. branches or leaves. Type Two mainly consists of soil, sand, and a large amount of decayed animal matter, branches, or leaves. For Type One, smaller particles contain greater amounts of pollutant, while for Type Two, most of the pollutants are gathered in the coarser particles. In addition, the particle that contains the largest content of organic matter also contains the largest number of TN.