A high-rate anaerobic biofilm reactor for biomethane recovery from source-separated blackwater at ambient temperature.
anaerobic digestion
blackwater
conductive carbon fiber
direct interspecies electron transfer (DIET)
methanogenesis
Journal
Water environment research : a research publication of the Water Environment Federation
ISSN: 1554-7531
Titre abrégé: Water Environ Res
Pays: United States
ID NLM: 9886167
Informations de publication
Date de publication:
Jan 2021
Jan 2021
Historique:
received:
13
01
2020
revised:
03
04
2020
accepted:
07
04
2020
pubmed:
25
4
2020
medline:
30
12
2020
entrez:
25
4
2020
Statut:
ppublish
Résumé
Anaerobic bioreactors for source-separated blackwater are mostly operated at low organic loading rates (OLRs) due to low biodegradability and the potential of ammonia inhibition. In this study, an anaerobic biofilm reactor having conductive carbon fibers as the media was investigated for the high-rate treatment of blackwater collected from vacuum toilets. The bioreactor was operated at different OLRs ranged from 0.77 to 3.01 g COD/L-d in four stages for a total operating period of ~ 250 days. With the increase of OLRs, the specific methane production rate increased from 105.3 to 304.6 ml/L-d with high methane content in biogas (75.5%-83%). The maximum methane yield was achieved at hydraulic retention time (HRT) of 15 days. Highest organics and suspended solids removal (80%-83%) were achieved at 20-days HRT, while increased OLRs resulted in diminished removal efficiencies. The state variables, including pH, total ammonia nitrogen, short-chain volatile fatty acids, and soluble chemical oxygen demand, indicated the system had a great capability to withstand the high OLRs. Microbial community analysis revealed that the high performance might be attributed to direct interspecies electron transfer (DIET) facilitated by potentially electroactive bacteria (e.g., Syntrophomonas, Clostridium) and electrotrophic archaea (e.g., Methanosaeta and Methanosarcina species) enriched on the carbon fibers. PRACTITIONER POINTS: An anaerobic biofilm reactor was investigated for biomethane recovery from source-separated blackwater. Conductive carbon fibers were utilized as the media to stimulate enrichment of potentially electroactive methanogenic communities. The bioreactor was operated at ambient temperature for over 250 days. High methane production rate and high-quality biogas were achieved at OLRs ranged from 0.77 to 3.01 g COD/L-d. Microbial community analysis suggested direct interspecies electron transfer (DIET) between specific electroactive bacteria and electrotrophic archaea.
Substances chimiques
Sewage
0
Methane
OP0UW79H66
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
61-74Subventions
Organisme : Natural Sciences and Engineering Research Council of Canada
Informations de copyright
© 2020 Water Environment Federation.
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