Back to Search Start Over

Enhancing the anaerobic digestion process through carbon dioxide enrichment: initial insights into mechanisms of utilization.

Authors :
Bajón Fernández Y
Soares A
Vale P
Koch K
Masse AL
Cartmell E
Source :
Environmental technology [Environ Technol] 2019 May; Vol. 40 (13), pp. 1744-1755. Date of Electronic Publication: 2019 Apr 01.
Publication Year :
2019

Abstract

Carbon dioxide (CO <subscript>2</subscript> ) enrichment of anaerobic digesters (ADs) without hydrogen addition has been demonstrated to provide a potential solution to manage CO <subscript>2</subscript> streams generated in the water and organic waste sectors, with concomitant increases in methane (CH <subscript>4</subscript> ) production. This study investigates the CO <subscript>2</subscript> utilization mechanisms, by considering chemical and biological pathways in food waste and sewage sludge ADs. Methanosaetaceae was observed to be the dominant methanogen in sewage sludge ADs (Abundance of 83.8-98.8%) but scarce in food waste units (3.5-5.8%). Methanosarcinaceae was dominant in food waste (14.3-32.4%), likely due to a higher tolerance to the free ammonia nitrogen concentration recorded (885 mg L <superscript>-1</superscript> ). R <subscript>Methanosaetaceae</subscript> (ratio of Methanosaetaceae fluorescence signal between test and control) of 1.45 and 1.79 were observed for sludge ADs enriched once and periodically with CO <subscript>2</subscript> , respectively (p-value  < .05), suggesting a higher Methanosaetaceae activity associated with CO <subscript>2</subscript> enrichment. Reduction of CO <subscript>2</subscript> by homoacetogenesis followed by acetoclastic methanogenesis was proposed as a CO <subscript>2</subscript> utilization mechanism, which requires validation by radiolabelling or carbon isotope analysis.

Details

Language :
English
ISSN :
1479-487X
Volume :
40
Issue :
13
Database :
MEDLINE
Journal :
Environmental technology
Publication Type :
Academic Journal
Accession number :
30888257
Full Text :
https://doi.org/10.1080/09593330.2019.1597173