Bacterial decimation times in anaerobic digestions of animal slurries
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Bacterial decimation times in anaerobic digestions of animal slurries. / Elmerdahl Olsen, John.
I: Biological Wastes, Bind 21, Nr. 3, 1987, s. 153-168.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Bacterial decimation times in anaerobic digestions of animal slurries
AU - Elmerdahl Olsen, John
PY - 1987
Y1 - 1987
N2 - The reductions of pathogenic and indicator bacteria in animal slurry subjected to mesophilic (35°C) and thermophilic (53°C) anaerobic digestion have been measured in small-scale, as well as full-scale, reactors. For all vegetative bacteria a time-dependent inactivation was observed. At small-scale digestion at 35°C average T90 values were 2·4 days for Salmonella typhimurium, 2·0 days for S. dublin and Streptococcus faecalis, 1·8 days for Escherichia coli and Erysipelothrix rhusiopathiae, 0·9 days for Staphylococcus aureus and 7·1, 3·2 and 3·1 days for group D-streptococci, faecal coliforms and total coliforms of the indigenous flora. At 53°C T90 values of 1·2 h were determined for E. rhusiopathiae, 1·0 h for Str. faecalis, 0·7 h for S. typhimurium, 0·6 h for S. dublin, 0·5 h for Staph. aureus and 0·4 h for E. coli. Spores of Clostridium perfringens type C and Bacillus cereus were not inactivated at 35°C or 53°C. The value of T90 was significantly correlated to species of bacteria and temperature during digestion, but in general it was not influenced by the type of slurry (cattle or pig), the reactor process (batch or continuous), the amount of gas produced during fermentation, the slurry dry-matter contents, the concentration of NNH3 and pH in the slurry. T90 values for S. typhimurium and E. coli at full-scale digestion were fully comparable to the values determined by small-scale experiments.
AB - The reductions of pathogenic and indicator bacteria in animal slurry subjected to mesophilic (35°C) and thermophilic (53°C) anaerobic digestion have been measured in small-scale, as well as full-scale, reactors. For all vegetative bacteria a time-dependent inactivation was observed. At small-scale digestion at 35°C average T90 values were 2·4 days for Salmonella typhimurium, 2·0 days for S. dublin and Streptococcus faecalis, 1·8 days for Escherichia coli and Erysipelothrix rhusiopathiae, 0·9 days for Staphylococcus aureus and 7·1, 3·2 and 3·1 days for group D-streptococci, faecal coliforms and total coliforms of the indigenous flora. At 53°C T90 values of 1·2 h were determined for E. rhusiopathiae, 1·0 h for Str. faecalis, 0·7 h for S. typhimurium, 0·6 h for S. dublin, 0·5 h for Staph. aureus and 0·4 h for E. coli. Spores of Clostridium perfringens type C and Bacillus cereus were not inactivated at 35°C or 53°C. The value of T90 was significantly correlated to species of bacteria and temperature during digestion, but in general it was not influenced by the type of slurry (cattle or pig), the reactor process (batch or continuous), the amount of gas produced during fermentation, the slurry dry-matter contents, the concentration of NNH3 and pH in the slurry. T90 values for S. typhimurium and E. coli at full-scale digestion were fully comparable to the values determined by small-scale experiments.
UR - http://www.scopus.com/inward/record.url?scp=0023178812&partnerID=8YFLogxK
U2 - 10.1016/0269-7483(87)90121-2
DO - 10.1016/0269-7483(87)90121-2
M3 - Journal article
AN - SCOPUS:0023178812
VL - 21
SP - 153
EP - 168
JO - Biological Wastes
JF - Biological Wastes
SN - 0269-7483
IS - 3
ER -
ID: 257698822