Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Performance Evaluation of the Dual Digestion System.
Author Appelton, A. R. ; Leong, C. L. ;
CORP Author Montgomery (James M.), Inc., Pasadena, CA.;Environmental Protection Agency, Cincinnati, OH. Water Engineering Research Lab.
Year Published 1986
Report Number EPA-68-03-1821; EPA/600/D-86/030;
Stock Number PB86-156320
Additional Subjects Sewage treatment ; Pathogens ; Sludge disposal ; Aerobic processes ; Anaerobic processes ; Oxidation ; Fertilizers ; Microbiology ; Tables(Data) ; Performance evaluation ; Heat recovery ; Bacteria ; Dual digestion systems ; Sludge treatment ; Land disposal ; Waste utilization ; Biogas
Library Call Number Additional Info Location Last
NTIS  PB86-156320 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/21/1988
Collation 24p
The dual digestion system (DDS) was developed to provide stabilized, pathogen free sludge. DDS consists of a 1-day detention time, pure-oxygen, covered aerobic digester (Step I) followed by an 8-day detention time anaerobic reactor. The temperature in the Step I digester is controlled by adjusting the pure oxygen feed rate. The heat generated through oxidation of volatile matter in the raw sludge is conserved in the Step I digester. No additional sludge heating is provided for anaerobic digestion in Step II so the biogas generated in Step II is available for other uses throughout the plant. Operation of DDS during the special study at the Lackawanna Wastewater Treatment Plant demonstrated that adequate total volatile solids reduction could be achieved relative to processes to significantly reduce pathogens (PSRP) and processes to further reduce pathogens (PFRP). Reductions of the three indicator microbiological parameters of interest through DDS treatment were greater than those achieved by PSRPs and greater than or equal to those achieved by thermophilic aerobic digestion, a PFRP. Salmonella spp. data were difficult to compare, but it appears that greater reductions of the pathogenic bacteria can be achieved with PSRPs. Regrowth of Salmonella spp. in the Step II digester was not observed during the study.