Microflora communities which can convert digested sludge to biogas.
Environ Technol
; 43(15): 2391-2403, 2022 Jun.
Article
em En
| MEDLINE
| ID: mdl-33475466
ABSTRACT
In the present study, we developed several microflora communities that utilize digested sludge (DS), the recalcitrant waste product of anaerobic digestion, as a substrate for biogas production with the aim of their future application to DS recycling. Strict enrichment with DS as the sole nutrient source was introduced to culture microbes from soil and herbivore dung samples; microflora communities promoting stable levels of biogas production were obtained. The average methane and hydrogen yield from soil-derived microflora were 4.86 and 0.94â
ml per 1.0â
g DS, respectively. Notably, two microflora communities enriched from a riverbank sediment produced 20.79â
ml and 14.10â
ml methane from 1.0â
g DS. By contrast, the methane and hydrogen yield for herbivore dung-derived microfloras were on average 1.31â
ml and 1.87â
ml per 1.0â
g DS, respectively. Potent hydrogen-biogas producers were obtained from rabbit (4.12â
ml per 1.0â
g DS), goat (3.16â
ml per 1.0â
g DS), and sheep dung (2.52â
ml per 1.0â
g DS). The cultured microflora communities included representatives from the eubacterial genera, Clostridiaceae and Eubacteriaceae together with several anaerobic genera. Pseudomonas spp. are found in the riverbank sediment-derived microfloras, suggesting that the floras employ syntrophic acetate oxidation and hydrogentrophic methanogenesis (SAO-HM) pathway for methane production. The methanogenic microflora communities were dominated by bacteria from the Methanobacteriaceae family and unclassified archaea. Moreover, ascomycetous fungi and protists were found, implying that they act as oxygen scavengers and bacterial grazers, respectively. Enzymatic analysis suggested that the microfloras hydrolyze DS via cellulase, chitinase, and protease activities.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Esgotos
/
Biocombustíveis
Limite:
Animals
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article