Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Civil and Environmental Engineering


Reduction of eutrophication of surface waters requires control of phosphorus discharges from wastewater treatment plants into receiving water bodies. Phosphorus concentrations in the wastewater and removal in the main treatment units at the Brookings Municipal Wastewater Treatment Facility (B\VWTF) were observed. The phosphorus concentration in the influent wastewater at the BWWTF was found to be 13 .0 mg/Las P whereas in the plant effluent it was 4.4 mg/L. The overall removal of phosphorus from the plant was 66 percent. A feasibility study for biological phosphorus removal (BPR) for primary settled wastewater from the BWWTF was conducted in the laboratory. The two-stage anaerobicaerobic BPR process in the laboratory produced similar effluent phosphorus concentrations as from the conventional activated sludge process. Three-stage University of Cape Town (UCT) type BPR process resulted in better phosphorus removals when compared to the conventional activated sludge process for similar feed wastewater. The UCT type BPR process exhibited phosphorus concentrations as low as 2.3 mg/Las P. Performance of the UCT process was further studied by adding additional soluble BOD in the feed wastewater. The UCT process, with enriched feed, resulted in much lower phosphorus concentrations (as low as 0.5 mg/L as P in the effluent). The UCT type BPR process with enriched feed resulted in 93% reduction in phosphorus concentrations. Sufficient soluble BOD in the influent of BPR process was found necessary to obtain low concentrations of effluent phosphorus. If the influent total BOD5 of wastewater from the BWWTF is converted into soluble BOD, the UCT-type BPR process was found feasible to meet effluent phosphorus concentrations as low as 0. 5 mg/L.

Library of Congress Subject Headings

Sewage -- Purification -- Phosphate removal -- South Dakota -- Brookings Sewage -- Purification -- Biological treatment -- South Dakota -- Brookings



Number of Pages



South Dakota State University