Filter Loading Evaluation for Water Reuse
Principal Investigators and Project Manager
Kara L. Nelson, Ph.D., University of California, Berkeley
Gordon Williams, Ph.D., University of California, Berkeley
Bahman Sheikh, Ph.D., P.E., Water Reuse Consultant
Bob Holden, P.E., Monterey Regional Water Pollution Control Agency
James Crook, Ph.D., P.E, Monterey Regional Water Pollution Control Agency
Robert C. Cooper, Ph.D., BioVir Laboratories
The overall goal of the Filter Loading Evaluation for Water Reuse (FLEWR) project was to address scientific, engineering, and regulatory gaps related to the impact of filter loading rate on granular media, rapid depth filtration of wastewater. Higher filter loading rates would allow more water to be recycled with minimal cost implications. Because of the regulatory implications of the project, the California Department of Public Health (CDPH) was consulted on a regular basis and was directly involved in establishing equivalency criteria for filter effluent quality.
The FLEWR project was divided into two phases of activities. The goals of Phase I were to
- Investigate the impact of filter loading rate (5, 6.25, 7.5, 8.75, 10 gal/ft2-min; 12.2, 15.3, 18.3, 21.4, 24.4 m/h) on filter performance and effluent quality at the pilot scale.
- Characterize filter performance and effluent quality sufficiently to seek approval from regulatory agencies to operate full-scale tertiary filters higher than 5 gal/ft2-min during Phase II (as determined by the California Department of Public Health Equivalency criteria).
The goals of Phase II were to
- Investigate the impact of filter loading rate (5 and 7.5 gal/ft2×min; 12.2 and 18.3 m/h) at five full-scale treatment plants.
- Conduct additional laboratory and pilot-scale experiments on virus removal mechanisms during filtration.
A process was developed in this study for water reclamation plants in California to demonstrate that their tertiary granular media filters can be operated at a higher loading rate with performance equivalent to that achieved when operating at a lower rate. After obtaining a temporary waiver to conduct testing and then performing the actual testing, if a treatment facility successfully meets the equivalency criteria, a treatment facility can prepare and submit a final report to the California Department of Public Health seeking permanent approval for operation at a higher loading rate.
(2011, 189 pages, 02-003-1)
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