Due: Not determined for S2002

Secondary Sedimentation

Work as a team of two for this assignment.

Deliverables : Due with this assignment, the spreadsheet with calculations. Additional work related to this assignment will be due with the next design assignment. For the design assignment you will also be required to submit a written design with explanations and drawings, presentation. This project will be presented during class at a time to be announced later.

Size secondary settling facilities for the City of Spunkindale, Illinois' wastewater treatment plant. Use a minimum of two tanks. Provide the diameter and depth of the tanks. Also, indicate the detention time at average flow, the overflow rate at both peak and average flow, and the weir loading at peak flow. Show all calculations on the attached spreadsheet. Spunkindale has an average flow of 12 MGD and a peak flow of 25 MGD. The biological process is high-rate activated sludge. Include in your report and presentation, the clarifier sizes required for a return solids concentration between 8 and 12 g/L and for inlet solids concentrations ranging from 2800 to 3200 mg/L. (Evaluate the system at the four possible combinations of inlet solids and return solids, and choose the larger of the four sizes.) Also, compare the sizes you obtain to the established values for overflow rate (at average and peak) and detention time (average only).

Download the settling data as an Excel spreadsheet .

Typical design data for secondary sedimentation facilities follows.