Settleable Solids from Combined Sewers: Settling, Stormwater Treatment, and Sedimentation Rates in Rivers

Settleable solids are an important pathway for pollutants found in river sediments. To study settling behaviour of settleable solids, settling velocity was measured by a settling apparatus. Special measurements were undertaken to determine the relationship between the settling distribution of settleable solids and their pollutant load - organic mass, chemical oxygen demand, heavy metals and organic micropollutants. To calculate where settleable solids from combined sewer systems will settle in receiving waters, the settling distribution is also useful. The results of a three-year research indicate that stormwater treatment by settling is effective in preventing adverse environmental impacts of combined sewage pollutants.