The University of Massachusetts Amherst
University of Massachusetts Amherst

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Particle size and chemical effects on contact filtration performance

TitleParticle size and chemical effects on contact filtration performance
Publication TypeJournal Article
Year of Publication1993
AuthorsTobiason JE, Johnson GS, Westerhoff P, Vigneswaran B
JournalJournal Environmental Engineering
Start Page520
Date Published05/1993
KeywordsCalcium, Chloride, filtration, Head loss (fluid mechanics), particle size distribution, Particles, polymer

This work involves a laboratory‐scale investigation of the effects of suspended particle size and coagulant type on the performance of contact or inline direct filtration (no flocculation). Dilute monodisperse and polydisperse suspensions of polystyrene particles (0.27‐, 1.24‐, 1.32‐, and 10‐μm diameters) were applied to shallow beds of 0.4‐mm glass‐bead filter media after destabilization with either cationic polymer or calcium chloride. The particle removal and head‐loss results show dramatic effects of particle size on filtration performance. Submicron particles significantly improve the removal of larger particles in mixed size suspensions and also dominate head‐loss development. Head‐loss development is typically linear with time and for mixed suspensions is the same as, or somewhat lower than, head loss for monodisperse suspensions of the smaller‐sized particle. Polymer destabilization generally causes more head loss than calcium chloride destabilization for a similar extent of particle deposition. - See more at: