Effects of flocculation on direct filtration performance

Paul K. Westerhoff, John E. Tobiason

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The Surface Water Treatment Rule (SWTR) will require filtration of most surface waters, as the EPA recognizes filtration and disinfection as methods to meet specified goals for the removal and/or inactivation of a variety of microorganisms of health concern, including viruses and Giardia cysts. These biological 'particles' vary greatly in size (i.e., 0.05 μm versus 10 μm), as well as other characteristics. This, and the fact that many previously unfiltered supplies of high quality may be treated by direct (coagulation, flocculation, filtration) or contact (coagulation, filtration) filtration, suggests the need for an improved understanding of the role of suspended particle size and flocculation in filtration performance. The objective of this study was to investigate the effects of chemical addition and flocculation duration on filtration performance as measured by particle removal and head loss development.

Original languageEnglish (US)
Title of host publicationWater Research for the New Decade
PublisherPubl by American Water Works Assoc
Number of pages14
ISBN (Print)0898675901
StatePublished - Dec 1 1991
Externally publishedYes
EventProceedings of the 1991 AWWA Annual Conference - Philadelphia, PA, USA
Duration: Jun 23 1991Jun 27 1991

Publication series

NameProceedings - AWWA Annual Conference
ISSN (Print)0360-814X


OtherProceedings of the 1991 AWWA Annual Conference
CityPhiladelphia, PA, USA

ASJC Scopus subject areas

  • General Engineering


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