Abstract
The effects of microwave (MW) pretreatment were investigated by six anaerobic digesters operated under thermophilic and mesophilic conditions at high organic loading rates (4.9-5.7 g volatile solids/L/d). The experiments and analyses were mainly designed to reveal the impact of MW pretreatment and digester temperatures on the process stability and microbial community structure by correlating the composition of microbial populations with volatile fatty acid (VFA) concentrations. A slight shift from biogas production (with a reasonable methane content) to VFA accumulation was observed in the thermophilic digesters, especially in the MW-irradiated reactors. Microbial population structure was assessed using a high-throughput sequencing of 16S rRNA gene on the MiSeq platform. Microbial community structure was slightly affected by different MW pretreatment conditions, while substantially affected by the digester temperature. The phylum Bacteroidetes proliferated in the MW-irradiated mesophilic digesters by resisting high-temperature MW (at 160 °C). Hydrogenotrophic methanogenesis (mostly the genus of Methanothermobacter) was found to be a key route of methane production in the thermophilic digesters, whereas aceticlastic methanogenesis (mostly the genus of Methanosaeta) was the main pathway in the mesophilic digesters.
| Original language | English |
|---|---|
| Article number | 887 |
| Journal | Water (Switzerland) |
| Volume | 12 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1 Mar 2020 |
Bibliographical note
Publisher Copyright:© 2020 by the authors.
Funding
Portions of this research were funded by "The Scientific and Technological Research Council of Turkey (TUBITAK)-International Research Fellowship Program (2214/A)" and "The Natural Sciences and Engineering Research Council (NSERC)-Collaborative Research and Development Grant (No: J462765-13)". The authors would like to thank TUBITAK and NSERC for their financial support. The authors express their gratitude to Dr. Muneer Ahmad for his assistance in the coordination of samples for genomic analysis. The authors also thank Timothy Abbott (Ph.D. candidate at the University of British Columbia Okanagan) for his assistance in providing sludge samples from the wastewater treatment plant. Furthermore, the authors would like to thank Hina Dilawar (M.A.Sc. student at the University of British Columbia Okanagan) for her proofreading. Acknowledgments: The authors would like to thank TUBITAK and NSERC for their financial support. The authors express their gratitude to Dr. Muneer Ahmad for his assistance in the coordination of samples for genomic analysis. The authors also thank Timothy Abbott (Ph.D. candidate at the University of British Columbia Okanagan) for his assistance in providing sludge samples from the wastewater treatment plant. Furthermore, the authors would like to thank Hina Dilawar (M.A.Sc. student at the University of British Columbia Okanagan) for her proofreading. Funding: Portions of this research were funded by “The Scientific and Technological Research Council of Turkey (TUBITAK)—International Research Fellowship Program (2214/A)” and “The Natural Sciences and Engineering Research Council (NSERC)—Collaborative Research and Development Grant (No: J462765-13)”.
| Funders | Funder number |
|---|---|
| TUBITAK | 2214/A |
| Timothy Abbott | |
| Natural Sciences and Engineering Research Council of Canada | J462765-13 |
| Türkiye Bilimsel ve Teknolojik Araştirma Kurumu |
Keywords
- Anaerobic digestion
- Bioenergy
- Illumina high-throughput sequencing
- Microbial community structure
- Microwave
- Municipal sludge
- Thermal pretreatment
- Volatile fatty acids
