Record Display for the EPA National Library Catalog


Main Title Hydraulic characteristics of activated sludge secondary clarifiers /
Author Bender, Jon.
Other Authors
Author Title of a Work
Crosby, Robert M.
Publisher U.S. Environmental Protection Agency, Municipal Environmental Research Laboratory : Center for Environmental Research Information [distributor],
Year Published 1984
Report Number EPA/600-S2-84-131
OCLC Number 11577794
Subjects Sewage sludge. ; Sewage clarifiers.
Internet Access
Description Access URL
Library Call Number Additional Info Location Last
EJBD ARCHIVE EPA 600-S2-84-131 In Binder Headquarters Library/Washington,DC 11/28/2017
EJBD  EPA 600-S2-84-131 In Binder Headquarters Library/Washington,DC 11/05/2018
Collation 6 pages : illustrations ; 28 cm
Caption title. At head of title: Project summary. Distributed to depository libraries in microfiche. "Sept. 1984." "EPA/600-S2-84-131."
Contents Notes
"The hydraulic characteristics of several common types of full-scale activated sludge secondary clarifiers were evaluated. Attempts were then made to modify and improve representative examples. The tanks' characteristics were inferred by the use of innovative dye tracer techniques. The effects of modifications were evaluated on the basis of effluent quality. The dominant hydraulic characteristic of all clarifiers studied was density flow. In most cases, the density flow had a significant effect on effluent suspended solids concentrations. When effluent weirs were placed in the path of density flow, effluent quality was generally poor. Preventing density current formation by inlet modification was not nearly as effective as interrupting flows at midradius and near the weirs. Problems also occurred with balancing flows between parallel clarifiers. The cause was improper application of mixed liquor feed valves, poor splitter box design, and inadequate flow measurement. In addition, strong evidence exists that flow transients are not attenuated by upstream unit processes and may significantly affect the solids transport through clarifiers."