The Effect of Sedimentation on Filtration Performance At the OWASA Water Treatment Plant
Public Deposited- Last Modified
- February 27, 2019
- Creator
-
Meyer, Douglas Eric
- Affiliation: Gillings School of Global Public Health, Department of Environmental Sciences and Engineering
- Abstract
- Due to projected increases in water demand, the Orange Water and Sewer Authority needs to know what, if anything, is required to upgrade its legal filtration rate from 4 gpm/ft^2 to 6 gpm/ft^2. Current theory is not adequately developed to predict the effect of sedimentation on all the important filtration parameters. Thus pilot testing was used in conjunction with full scale operation to determine how additional sedimentation could help. The pilot plant was constructed with vertical flow sedimentation basins in series with the horizontal flow sedimentation basins in the fullscale plant. Pilot plant filters were identical to the fullscale filters. Tests were run between 8 January 1986 and 10 May 1986. In these tests it was found that neither sedimentation nor filtration parameters had an effect on filtered water turbidities (for raw water turbidities < 50 NTU) nor filtered water aluminum concentration (for raw water turbidities < 8 NTU). However, sedimentation overflow rate was shown to determine the amount of headloss after given filter run lengths. Therefore, sedimentation can control the operation of the filters, but not the quality of the filtered water. A method was devised to extrapolate the results of the pilot plant study to determine the ability of the existing Orange Water and Sewer Authority facility to handle greater flow rates in the future. The current physical plant is capable of producing 12 MGD at a filtration rate of 6 gpm/f^2 without additional sedimentation basins. This includes a margin of safety for daily operation and maintenance but not for extended down time maintenance.
- Date of publication
- June 1986
- DOI
- Resource type
- Rights statement
- In Copyright
- Advisor
- Leith, David
- DiGiano, Francis A.
- Singer, Philip
- Degree
- Master of Science in Environmental Engineering
- Academic concentration
- Water Resources Engineering
- Degree granting institution
- University of North Carolina at Chapel Hill
- Graduation year
- 1986
- Language
- Deposit record
- 4229e0fb-b010-4ede-aa50-9d4a2f0726fb
Relations
- Parents:
This work has no parents.