A pig slurry feast/famine feeding regime strategy to improve mesophilic anaerobic digestion efficiency and digestate hygienisation

The increasing concentration of livestock farms results in large amounts of waste production and the need for their management. The study of anaerobic digestion (AD) technology, under mesophilic conditions, applied to pig slurry is of the upmost importance for biogas recovery and sanitised digestate...

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Détails bibliographiques
Publié dans:Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA. - 1991. - 39(2021), 7 vom: 01. Juli, Seite 947-955
Auteur principal: Silva, I (Auteur)
Autres auteurs: Jorge, C, Brito, L, Duarte, E
Format: Article en ligne
Langue:English
Publié: 2021
Accès à la collection:Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA
Sujets:Journal Article Anaerobic digestion (AD) Clostridia circular bioeconomy livestock mesophilic conditions pig slurry management Biofuels Manure Methane OP0UW79H66
Description
Résumé:The increasing concentration of livestock farms results in large amounts of waste production and the need for their management. The study of anaerobic digestion (AD) technology, under mesophilic conditions, applied to pig slurry is of the upmost importance for biogas recovery and sanitised digestate, contributing to a circular economy. The assessment of the effects of a feast/famine regime on biogas and biomethane (bio-CH4) yield with different feeding frequencies was performed. The evaluation was made in regards to three scenarios: the first is based on daily feeding (FR1); in the second, the feeding occurs once every two days (FR2); and in the third, the feeding happens once every three days (FR3). The results demonstrate that the biogas and methane yield increased by 34% and 37% between FR1 and FR3. The stability inside the reactor was maintained since specific loading energetic rate values did not exceed the recommended limit (0.4 d-1). It was also possible to conclude that the AD technology was efficient to sanitise the pig slurry, with the count of Escherichia coli going from 1 × 105 colony-forming units (CFU) g-1 to less than 100 CFU g-1, meeting the legal requirements for agricultural valorisation. The total anaerobic mesophile plate counts were significantly (p < 0.1) reduced from feeding to digestate, and the plate counts of Clostridia were significantly (p < 0.05) increased, reflecting the changes in the composition of the microbiota. The increasing yield in bio-CH4 in accordance with Clostridium counts suggests this genus as a positive microbiological key indicator of the AD performance
Description:Date Completed 13.07.2021
Date Revised 13.07.2021
published: Print-Electronic
Citation Status MEDLINE
ISSN:1096-3669
DOI:10.1177/0734242X20972794