Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Evaluation of Sedimentation and Filtration for Microorganism Removal.
Author Logsdon, G. S. ; Rice, E. W. ;
CORP Author Environmental Protection Agency, Cincinnati, OH. Drinking Water Research Div.
Year Published 1985
Report Number EPA/600/D-85/138;
Stock Number PB85-233443
Additional Subjects Microorganism control(Water) ; Sedimentation ; Filtration ; Water treatment ; Bacteria ; Microorganisms ; Pilot plants ; Disinfection ; Performance evaluation ; Potable water ; Giardia cysts
Library Call Number Additional Info Location Last
NTIS  PB85-233443 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 06/21/1988
Collation 27p
Removals of bacteria and Giardia cysts in a pilot plant sedimentation basin were evaluated and compared with turbidity removal. Removal was studied during normal operating conditions, during initial period of filter operation after backwashing, and during times of turbidity breakthrough. It was concluded that continuous flow sedimentation basins can remove a substantial fraction (perhaps up to 90 percent) of bacteria or cysts in the applied water. Microorganism reduction may be similar to turbidity reduction on a percentage basis. The tendency of filters to produce water with somewhat elevated turbidity upon restart after backwashing is accompanied by a tendency to pass higher concentrations of cysts and bacteria at the same time. Pilot plant data showed that the probability of attaining high numbers of bacteria or Giardia cysts in filtered water was greater when filtered water turbidities ranged from 0.21 to 1.4 ntu in contrast with data with filtered water turbidities not exceeding 0.20 ntu.