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Removing Cryptosporidium using multimedia filters
Author(s) -
Ongerth Jerry E.,
Pecoraro Julie Proctor
Publication year - 1995
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.1551-8833.1995.tb06468.x
Subject(s) - cryptosporidium , filtration (mathematics) , giardia , raw water , coagulation , filter (signal processing) , alum , environmental science , pilot plant , water treatment , pulp and paper industry , environmental engineering , biology , microbiology and biotechnology , chemistry , waste management , mathematics , engineering , medicine , statistics , electrical engineering , organic chemistry , psychiatry , feces
Direct granular‐media filtration appears to provide a degree of control for Cryptosporidium oocysts, i.e., up to about 3 logs, during periods of optimal coagulation. A pilot‐scale water filtration plant was used to measure removal efficiencies of Cryptosporidium oocysts and Giardia cysts simultaneously. The 1‐gpm pilot plant using multimedia filters was operated in the direct filtration mode at 5 gpm/sq ft. Raw water was well conditioned by pH adjustment and alum coagulation. Carefully prepared and counted Cryptosporidium oocysts and Giardia cysts were seeded into the raw water continuously during test filter runs. Plant performance was characterized by analysis of samples collected before and after filtration. After a ripening period, removals observed in the optimal runs for Cryptosporidium averaged from 2.7 to 3.1 logs, and removals for Giardia averaged from 3.1 to 3.5 logs.