Oxygen Transfer between Resuspended Organic Sediments and the Fluid Media
The McCook combined-sewer-overflow (CSO) reservoir, being designed as a flood control retention basin for the city of Chicago, Illinois, is expected to go anaerobic and to generate objectionable odors. As a result, an aeration system will be necessary. For the design of the aeration system, is important to have knowledge of the oxygen demand from the sediments, taking into consideration that aeration will resuspend sediments, and thus increase oxygen demand. This research focuses on determining the effect to the dissolved oxygen (DO) uptake due to the resuspended sediments from the bottom of the reservoir. The laboratory apparatus used for experimentation is an annular flume consisting of a rotating ring-like flume and lid, set up to produce controlled water movement. Crushed walnut shells placed in a water media simulated organic sediments from the reservoir. A Clark type oxygen electrode was used for measuring DO. The variables in the experiment were flow velocity and sediment concentration. Dissolved oxygen was measured over time for different flow velocities, along with suspended sediment concentrations taken at different water depths at the end of each experiment. The DO uptake was found to be increasingly proportional to the concentration of suspended sediments, and independent of DO concentration and time.
School:
University of Illinois at Urbana-Champaign
Department:
Civil and Environmental Engineering
Research Advisor:
Marcelo García
Department of Research Advisor:
Civil and Environmental Engineering
Year of Publication:
2002