气候变化领域集成服务门户(CCPortal): Groundwater nitrification and denitrification are not always strictly aerobic and anaerobic processes, respectively: an assessment of dual-nitrate isotopic and chemical evidence in a stratified alluvial aquifer

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DOI	10.1007/s10533-020-00637-y
	Groundwater nitrification and denitrification are not always strictly aerobic and anaerobic processes, respectively: an assessment of dual-nitrate isotopic and chemical evidence in a stratified alluvial aquifer
	Utom A.U.; Werban U.; Leven C.; Müller C.; Knöller K.; Vogt C.; Dietrich P.
发表日期	2020
ISSN	1682563
卷号	147 期号:2
英文摘要	Nitrification and denitrification are traditionally assumed to occur under aerobic and anoxic conditions, respectively. However, new and interesting alternatives challenge the traditional assumption. Along this line, we provide dual-nitrate isotopic and chemical evidence for the occurrence of denitrification linked with heterotrophic nitrification in an upper oxic region and nitrification in an underlying low-oxygen (sub-oxic/anoxic) layer of a stratified and channelized alluvial aquifer. Particularly significant is the source of the oxidant required for nitrification within the deeper low-oxygen layer. Combined with the existence of steep geochemical gradients, the introduction of a favorable manganese oxide oxidant from the upper oxic layer into the underlying low oxygen region during diffusive mixing resulted in the higher concentrations of nitrate observed (due to the anoxic reoxidation of nitrite to nitrate) as well as the strong positive correlation of nitrite/nitrate with manganese (II) ion concentrations (in the deeper anoxic layer compared with the shallower oxic layer). The observations and findings presented herein have implications for not only reconciling the discrepancies in such unconventional pathways of nitrogen metabolism between groundwater ecosystems and river/stream/soil/marine systems (where such processes have most commonly been reported) but also for devising effective nitrogen nutrient remediation and complex nitrogen-cycling modeling strategies. © 2020, Springer Nature Switzerland AG.
英文关键词	Anoxic nitrification; Manganese oxide reduction; Nitrogen biogeochemical cycling; Oxic denitrification; Steep concentration gradients; Stratified aquifer
学科领域	anoxic conditions; aquifer characterization; denitrification; groundwater resource; isotopic composition; manganese oxide; oxic conditions; water chemistry
语种	英语
scopus关键词	anoxic conditions; aquifer characterization; denitrification; groundwater resource; isotopic composition; manganese oxide; oxic conditions; water chemistry
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/120389
作者单位	Department of Monitoring and Exploration Technologies (MET), Helmholtz Center for Environmental Research – UFZ, Permoserstraße 15, Leipzig, 04318, Germany; Center for Applied Geoscience (ZAG), University of Tübingen, Sigwartstr. 10, Tübingen, 72076, Germany; Department of Catchment Hydrology, Helmholtz Center for Environmental Research – UFZ, Theodor-Lieser-Straße 4, Halle (Salle), 06120, Germany; Department of Isotope Biogeochemistry, Helmholtz Center for Environmental Research – UFZ, Permoserstraße 15, Leipzig, 04318, Germany
推荐引用方式 GB/T 7714	Utom A.U.,Werban U.,Leven C.,et al. Groundwater nitrification and denitrification are not always strictly aerobic and anaerobic processes, respectively: an assessment of dual-nitrate isotopic and chemical evidence in a stratified alluvial aquifer[J],2020,147(2).
APA	Utom A.U..,Werban U..,Leven C..,Müller C..,Knöller K..,...&Dietrich P..(2020).Groundwater nitrification and denitrification are not always strictly aerobic and anaerobic processes, respectively: an assessment of dual-nitrate isotopic and chemical evidence in a stratified alluvial aquifer.Biogeochemistry,147(2).
MLA	Utom A.U.,et al."Groundwater nitrification and denitrification are not always strictly aerobic and anaerobic processes, respectively: an assessment of dual-nitrate isotopic and chemical evidence in a stratified alluvial aquifer".Biogeochemistry 147.2(2020).