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Influence of operating conditions on the persistence of E. coli, enterococci, Clostridium perfringens and Clostridioides difficile in semi-continuous mesophilic anaerobic reactors
- Source :
- Waste Management, Waste Management, Elsevier, 2021, 134, pp.32-41. ⟨10.1016/j.wasman.2021.08.003⟩
- Publication Year :
- 2021
-
Abstract
- International audience; This study examined the combined effect of hydraulic retention time (HRT), organic loading rate (OLR) and heat pretreatment of manure (70 degrees C, 1 h) on the fate of E. coli, enterococci, C. perfringens, C. difficile, and on chemical parameters (volatile fatty acids and ammonia) that may inactivate pathogens. Semi-continuous mesophilic anaerobic reactors were fed with pig manure and horse feed. The operating conditions were 2, 3, 4 COD.L-1.d(-1) (OLR), 24, 35, 46 days (HRT) and use or not of a thermal pretreatment. The levels of the chemical parameters did not reach concentrations capable of inactivating the four bacteria. Anaerobic digestion led to a Log io removal > 3 (E. coli), 0.9-2.1 (enterococci), 0.1-0.6 (C. perfringens) and 0-1 (C. difficile). Increasing HRT only reduced the concentration of E. coli in the digestate. Increasing OLR reduced the Log(10) removal of enterococci and C. difficile. The heat pretreatment led to non-detection of E. coli in the digestate, reduced the concentration of C. perfringens by 0.8-1.3 Log(10) and increased the concentration of C. difficile by 0.04-0.7 Log(10). Enterococci, not detected in the heated manure, were present in the digestate. The distribution of genes encoding virulence factors of C. difficile (tcdA and tcdB) and C. perfringens (cpa, cpb2 and cpb) was not impacted by anaerobic digestion or by the heat pretreatment. Enterococci, C. perfringens, C. difficile were present in the digestate at relatively stable concentrations regardless of the operating conditions, indicating that even with heat pretreatment, the biosafety of digestate cannot be guaranteed in mesophilic conditions.
- Subjects :
- Hydraulic retention time
Enterococci
Clostridium perfringens
Swine
Bacterial Toxins
medicine.disease_cause
7. Clean energy
03 medical and health sciences
Bioreactors
Clostridioides
Anaerobic digestion
medicine
Escherichia coli
Animals
Thermal treatment
Food science
Anaerobiosis
Horses
Waste Management and Disposal
030304 developmental biology
0303 health sciences
biology
[SDE.IE]Environmental Sciences/Environmental Engineering
030306 microbiology
Chemistry
Clostridioides difficile
Operational parameters
E. coli
biology.organism_classification
C. perfringens
Manure
13. Climate action
[SDE]Environmental Sciences
Digestate
C. difficile
Anaerobic exercise
Methane
Bacteria
Enterococcus
Mesophile
Subjects
Details
- ISSN :
- 18792456 and 0956053X
- Volume :
- 134
- Database :
- OpenAIRE
- Journal :
- Waste management (New York, N.Y.)
- Accession number :
- edsair.doi.dedup.....7eed118b08a62332baea01afe55c5829