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Source identification of nitrous oxide on autotrophic partial nitrification in a granular sludge reactor
| Title: | Source identification of nitrous oxide on autotrophic partial nitrification in a granular sludge reactor |
| Authors: | Rathnayake, R.M.L.D Browse this author | | Song, Y. Browse this author | | Tumendelger, A. Browse this author | | Oshiki, M. Browse this author | | Ishii, S. Browse this author | | Satoh, Hisashi Browse this author →KAKEN DB | | Toyoda, S. Browse this author | | Yoshida, N. Browse this author | | Okabe, S. Browse this author |
| Keywords: | Nitrous oxide production pathway | | Sequencing batch reactor | | Isotopomer analysis | | Microsensors | | In situ hybridization | | Hydroxylamine |
| Issue Date: | Dec-2013 |
| Publisher: | Elsevier |
| Journal Title: | Water Research |
| Volume: | 47 |
| Issue: | 19 |
| Start Page: | 7078 |
| End Page: | 7086 |
| Publisher DOI: | 10.1016/j.watres.2013.07.055 |
| PMID: | 24200002 |
| Abstract: | Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern since N2O is a major stratospheric ozone-depleting substance and an important greenhouse gas. The emission of N2O from a lab-scale granular sequencing batch reactor (SBR) for partial nitrification (PN) treating synthetic wastewater without organic carbon was therefore determined in this study, because PN process is known to produce more N2O than conventional nitrification processes. The average N2O emission rate from the SBR was 0.32 ± 0.17 mg-N L−1 h−1, corresponding to the average emission of N2O of 0.8 ± 0.4% of the incoming nitrogen load (1.5 ± 0.8% of the converted NH4+). Analysis of dynamic concentration profiles during one cycle of the SBR operation demonstrated that N2O concentration in off-gas was the highest just after starting aeration whereas N2O concentration in effluent was gradually increased in the initial 40 min of the aeration period and was decreased thereafter. Isotopomer analysis was conducted to identify the main N2O production pathway in the reactor during one cycle. The hydroxylamine (NH2OH) oxidation pathway accounted for 65% of the total N2O production in the initial phase during one cycle, whereas contribution of the NO2− reduction pathway to N2O production was comparable with that of the NH2OH oxidation pathway in the latter phase. In addition, spatial distributions of bacteria and their activities in single microbial granules taken from the reactor were determined with microsensors and by in situ hybridization. Partial nitrification occurred mainly in the oxic surface layer of the granules and ammonia-oxidizing bacteria were abundant in this layer. N2O production was also found mainly in the oxic surface layer. Based on these results, although N2O was produced mainly via NH2OH oxidation pathway in the autotrophic partial nitrification reactor, N2O production mechanisms were complex and could involve multiple N2O production pathways. |
| Relation: | http://www.sciencedirect.com/science/journal/00431354/ |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/53659 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 佐藤 久
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