High salinity in molasses wastewaters shifts anaerobic digestion to carboxylate production

De Vrieze, Jo, Coma, Marta, Debeuckelaere, Matthias, Van der Meeren, Paul and Rabaey, Korneel (2016) High salinity in molasses wastewaters shifts anaerobic digestion to carboxylate production. Water Research, 98 293-301. doi:10.1016/j.watres.2016.04.035

Author De Vrieze, Jo
Coma, Marta
Debeuckelaere, Matthias
Van der Meeren, Paul
Rabaey, Korneel
Title High salinity in molasses wastewaters shifts anaerobic digestion to carboxylate production
Journal name Water Research   Check publisher's open access policy
ISSN 1879-2448
Publication date 2016-07-01
Year available 2016
Sub-type Article (original research)
DOI 10.1016/j.watres.2016.04.035
Open Access Status Not Open Access
Volume 98
Start page 293
End page 301
Total pages 9
Place of publication London, United Kingdom
Publisher IWA Publishing
Language eng
Formatted abstract
Biorefinery wastewaters are often treated by means of anaerobic digestion to produce biogas. Alternatively, these wastewaters can be fermented, leading to the formation of carboxylates. Here, we investigated how lab-scale upflow anaerobic sludge blanket reactors could be shifted to fermentation by changing organic loading rate, hydraulic retention time, pH, and salinity. A strong increase in volatile fatty acid concentration up to 40 g COD L−1 was achieved through increasing salinity above 30 mS cm−1, as well as a decrease in methane production by more than 90%, which could not be obtained by adjusting the other parameters, thus, indicating a clear shift from methane to carboxylate production. Microbial community analysis revealed a shift in bacterial community to lower evenness and richness values, following the increased salinity and VFA concentration during the fermentation process. A selective enrichment of the hydrogenotrophic Methanomicrobiales took place upon the shift to fermentation, despite a severe decrease in methane production. Particle size distribution revealed a strong degranulation of the sludge in the reactor, related to the high salinity, which resulted in a wash-out of the biomass. This research shows that salinity is a key parameter enabling a shift from methane to carboxylate production in a stable fermentation process.
Keyword Carboxylate production
Microbial community
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
Advanced Water Management Centre Publications
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