Sedimentation

When wastewater is transported to the treatment plant, it is preliminarily treated to remove large debris and solids. The secondary treatment unit receives influx from the biological unit. Within the sedimentation treatment unit, the solids settle in the tanks. This chapter focuses on the primary tanks, where the physical settling process is the dominating action. Settling tanks are of great importance to the effectiveness of the wastewater treatment process. The main purpose of the study presented in the chapter was to optimize the design of large primary settling tanks for the city of Chicago. The major simulation cases were for the variations of tank depth. Other simulations also were done later for the design of details, such as inlet and outlet structures, feed well diameter and depth, and bottom slope. A more elaborate description of the model formulations and simulation steps can be found in the case folder.