Date of Award


Publication Type

Master Thesis

Degree Name



Civil and Environmental Engineering

First Advisor

Seth, Rajesh,


Engineering, Environmental.




The present study designed a coagulation-flocculation process for the treatment of wet weather flows and combined sewer overflows using a modified jar test and examined the effect of addition of micro carrier (MC) on the designed process performance. Aluminum sulfate was selected as the primary coagulant and an anionic polymer was used as a coagulant aid. Bench-scale studies revealed that rapid mixing with alum for at least 30 sec at a G value of 246 s-1 in the polymer-aided system followed by slow mixing for 1 min at a G value of 62 s-1 was adequate and effective for the alum coagulation. The time of the polymer addition was established at 40 sec after adding alum during 1 min rapid mixing. The alum dosage of 14.6 mg Al3+/L combined with 1.5 mg/L polymer dosage was the most effective in terms of the turbidity and SS removal. With this dosage combination, SS and turbidity removal efficiencies in excess of 95% were achieved after settling for 8 min as compared to less than 80% removal obtained by using alum alone. Upon the addition of MC, the settling time was significantly reduced from 8 min to 1 min with an equivalent removal efficiency of 95%. The MC concentration large than 3 g/L was the most effective in enhancing the settling ability of suspended solids. There were no significant differences found in terms of the improvement of the settling ability among the size fractions of the used MC in the present study. The performance of adding MC with the coagulant aid was the same as adding MC with alum in terms of turbidity removal. Results show that the primary coagulant dosage could be reduced due to the addition of polymer with an equivalent removal efficiency.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .Z57. Source: Masters Abstracts International, Volume: 43-01, page: 0292. Adviser: Rajesh Seth. Thesis (M.A.Sc.)--University of Windsor (Canada), 2004.