کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4480848 1623066 2016 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Source identification of nitrous oxide emission pathways from a single-stage nitritation-anammox granular reactor
ترجمه فارسی عنوان
شناخت منشا مسیرهای انتشار اکسید نیتروژن از راکتور گرانول تک مرحله ای A-nitritation anammox
کلمات کلیدی
مسیر تولید N2O؛ Nitritation-anammox ؛ راکتور میکروسنسور ؛ تجزیه و تحلیل isotopomer N2O؛ ماهی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی


• N2O production pathways were studied by N2O isotopic, FISH, and microsensor analyses.
• Ca. 70% of N2O was produced in nitrifiers-dominated oxic surface zone of granules.
• The rest of N2O (30%) was produced in the anammox bacteria-dominated anoxic zone.
• Overall, N2O was produced via NH2OH oxidation and NO2− reduction pathways equally.

Nitrous oxide (N2O) production pathway in a signal-stage nitritation-anammox sequencing batch reactor (SBR) was investigated based on a multilateral approach including real-time N2O monitoring, N2O isotopic composition analysis, and in-situ analyses of spatial distribution of N2O production rate and microbial populations in granular biomass. N2O emission rate was high in the initial phase of the operation cycle and gradually decreased with decreasing NH4+ concentration. The average emission of N2O was 0.98 ± 0.42% and 1.35 ± 0.72% of the incoming nitrogen load and removed nitrogen, respectively. The N2O isotopic composition analysis revealed that N2O was produced via NH2OH oxidation and NO2− reduction pathways equally, although there is an unknown influence from N2O reduction and/or anammox N2O production. However, the N2O isotopomer analysis could not discriminate the relative contribution of nitrifier denitrification and heterotrophic denitrification in the NO2− reduction pathway. Various in-situ techniques (e.g. microsensor measurements and FISH (fluorescent in-situ hybridization) analysis) were therefore applied to further identify N2O producers. Microsensor measurements revealed that approximately 70% of N2O was produced in the oxic surface zone, where nitrifiers were predominantly localized. Thus, NH2OH oxidation and NO2 reduction by nitrifiers (nitrifier-denitrification) could be responsible for the N2O production in the oxic zone. The rest of N2O (ca. 30%) was produced in the anammox bacteria-dominated anoxic zone, probably suggesting that NO2− reduction by coexisting putative heterotrophic denitrifiers and some other unknown pathway(s) including the possibility of anammox process account for the anaerobic N2O production. Further study is required to identify the anaerobic N2O production pathways. Our multilateral approach can be useful to quantitatively examine the relative contributions of N2O production pathways. Good understanding of the key N2O production pathways is essential to establish a strategy to mitigate N2O emission from biological nitrogen removal processes.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Water Research - Volume 102, 1 October 2016, Pages 147–157
نویسندگان
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