Record Display for the EPA National Library Catalog


Main Title Reductions of Enteric Microorganisms during Aerobic Sludge Digestion.
Author Martin, J. H. ; Bostian, H. E. ; Stern, G. ;
CORP Author Environmental Protection Agency, Cincinnati, OH. Risk Reduction Engineering Lab. ;Cornell Univ., Ithaca, NY. Center for Environmental Research.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/415;
Stock Number PB91-171702
Additional Subjects Sludge digestion ; Aerobic processes ; Aerobic bacteria ; Microorganism control(Sewage) ; Seasonal variations ; Water treatment ; Sludge disposal ; Municipalities ; Digestion(Decomposition) ; Enteroviruses ; Streptococcus ; Digesters ; Temperature effects ; Field tests ; Reprints ; Coliform bacteria ; Trumansburg(New York)
Library Call Number Additional Info Location Last
NTIS  PB91-171702 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 11p
Seasonal variations in the reductions of total coliform, fecal coliform, fecal streptococci, and enterovirus densities that occur during conventional aerobic sludge digestion in cold climates were characterized. Also, the potential to improve reductions in the densities of these four groups of enteric microorganisms in cold climates by simple modifications that increase process temperature by reducing heat losses was demonstrated. To obtain this data, two 32 cu m aerobic digesters located at a small municipal wastewater treatment plant were operated continuously over a period of twenty months. One digester was a conventional digester while the other was designed to minimize heat losses, and thus, facilities autoheating. When the results obtained during 11 separate periods of steady-state operation at mean mixed liquor temperatures ranging from 8 to 40 C and at residence times of 10, 15, and 20 days were combined for analysis, it was evident that significant reductions in the densities of the four groups of enteric microorganisms was dependent both residence time and temperature. Using the Arrhenius equation, it was possible to describe mathematically the temperature dependence of the rate of log10 reduction in density of each of these four groups of enteric microorganisms. The four mathematical relationships developed provide a rational basis to determine residence times necessary to achieve desired levels of indicator organism and enterovirus reductions during aerobic sludge digestion at mixed liquor temps. ranging from 8 to 40 C. (Copyright (c) Pergamon Press 1990.)