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Two‐Stage Filtration
Author(s) -
Kawamura Susumu
Publication year - 1985
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1985.tb05656.x
Subject(s) - filtration (mathematics) , flocculation , turbidity , raw water , settling , pulp and paper industry , slow sand filter , stage (stratigraphy) , water treatment , environmental science , environmental engineering , chromatography , process engineering , mathematics , chemistry , engineering , statistics , geology , paleontology , oceanography
A relatively new concept in the United States, the two‐stage filtration process incorporates an initial bank of coarse filters, followed by a bank of final filters that are normally operated at a high filtration rate. Pilot studies showed that two‐stage filtration is an attractive alternative to either conventional treatment or direct filtration, depending on the quality of the raw water. If the raw water frequently exhibits high turbidity or presents taste and odor problems, type 1 two‐stage filtration, which includes flocculation and settling, should be considered as the treatment alternative. The type 2 two‐stage process, involving neither flocculation nor settling, is suggested for cases in which the raw water quality is good enough to allow direct filtration.