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Huang J, Peng L, Ti C, Shan J, Wang S, Lan Q, Gao S, Yan X. Changes in source composition of wet nitrate deposition after air pollution control in a typical area of Southeast China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121649. [PMID: 38955049 DOI: 10.1016/j.jenvman.2024.121649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/20/2024] [Accepted: 06/28/2024] [Indexed: 07/04/2024]
Abstract
In recent years, China has adopted numerous policies and regulations to control NOx emissions to further alleviate the adverse impacts of NO3--N deposition. However, the variation in wet NO3--N deposition under such policies is not clear. In this study, the southeastern area, with highly developed industries and traditional agriculture, was selected to explore the variation in NO3--N deposition and its sources changes after such air pollution control through field observation and isotope tracing. Results showed that the annual mean concentrations of NO3--N in precipitation were 0.67 mg L-1 and 0.54 mg L-1 in 2014-2015 and 2021-2022, respectively. The average wet NO3--N depositions in 2014-2015 and 2021-2022 was 7.76 kg N ha-1 yr-1 and 5.03 kg N ha-1 yr-1, respectively, indicating a 35% decrease. The δ15N-NO3- and δ18O-NO3- values were lower in warm seasons and higher in cold seasons, and both showed a lower trend in 2021-2022 compared with 2014-2015. The Bayesian model results showed that the NOx emitted from coal-powered plants contributed 53.6% to wet NO3--N deposition, followed by vehicle exhaust (22.9%), other sources (17.1%), and soil emissions (6.4%) during 2014-2015. However, the contribution of vehicle exhaust (33.3%) overpassed the coal combustion (32.3%) and followed by other sources (25.4%) and soil emissions (9.0%) in 2021-2022. Apart from the control of air pollution, meteorological factors such as temperature, precipitation, and solar radiation are closely related to the changes in atmospheric N transformation and deposition. The results suggest phased achievements in air pollution control and that more attention should be paid to the control of motor vehicle exhaust pollution in the future, at the same time maintaining current actions and supervision of coal-powered plants.
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Affiliation(s)
- Jingwen Huang
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lingyun Peng
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chaopu Ti
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Jun Shan
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuwei Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qiao Lan
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Shuang Gao
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xiaoyuan Yan
- State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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Shaw C, Rastogi N, Rathi A, Kumar S, Meena R. Sources and processes affecting the abundances of atmospheric NH x using δ 15N over northwestern Indo-Gangetic plain. CHEMOSPHERE 2024; 359:142356. [PMID: 38761822 DOI: 10.1016/j.chemosphere.2024.142356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/29/2024] [Accepted: 05/15/2024] [Indexed: 05/20/2024]
Abstract
Ammonia (NH3) is the major constituent among all the reactive nitrogen species present in the atmosphere, and the most essential species for secondary inorganic aerosol formation. Recent satellite-based observations have identified the Indo-Gangetic Plain (IGP) as a major hotspot of global NH3 emission; however, the major sources and atmospheric processes affecting its abundance are poorly understood. The present study aims to understand the wintertime sources of NH3 over a semi-urban site (Patiala, 30.3°N, 76.4°E, 249 m amsl) located in the IGP using species specific δ15N in PM2.5. A distinct diurnal variation in the stable isotopic signature of total nitrogen (δ15N-TN) and ammonium (δ15N-NH4+) were observed; although, average day and night time concentrations of TN and NH4+ were similar. Mixing model results using δ15N-NH3 reveal the dominance of non-agricultural emissions (NH3 slip: 47 ± 24%) over agricultural emissions (24 ± 11%), combustion sources (19 ± 14 %), and biomass burning (10 ± 8%) for atmospheric NH3. Diurnal variability in source contributions to NH3 was insignificant. Further, significantly negative correlations of δ15N-NH4+ with ambient relative humidity (RH) and daytime NO3--N concentration were observed, and attributed to the possibility of NH4NO3 volatilization during day-time owing to lower RH and higher temperature, resulting in isotopic enrichment of the remaining NH4+ in aerosol phase. This study, a first of its type from India, highlights the importance of non-agricultural NH3 emissions over the agriculture dominated IGP region, and the role of local meteorology on the isotopic fractionation of δ15N in aerosol NH4+.
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Affiliation(s)
- Chandrima Shaw
- Geosciences Division, Physical Research Laboratory, Ahmedabad, 380009, India; Indian Institute of Technology Gandhinagar, Gandhinagar, 382355, India
| | - Neeraj Rastogi
- Geosciences Division, Physical Research Laboratory, Ahmedabad, 380009, India.
| | - Ajayeta Rathi
- Geosciences Division, Physical Research Laboratory, Ahmedabad, 380009, India; Indian Institute of Technology Gandhinagar, Gandhinagar, 382355, India
| | - Sanjeev Kumar
- Geosciences Division, Physical Research Laboratory, Ahmedabad, 380009, India
| | - Rohit Meena
- Geosciences Division, Physical Research Laboratory, Ahmedabad, 380009, India
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Huang W, Ye X, Lv Z, Yao Y, Chen Y, Zhou Y, Chen J. Dual isotopic evidence of δ 15N and δ 18O for priority control of vehicle emissions in a megacity of East China: Insight from measurements in summer and winter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172918. [PMID: 38697522 DOI: 10.1016/j.scitotenv.2024.172918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 03/31/2024] [Accepted: 04/29/2024] [Indexed: 05/05/2024]
Abstract
The source apportionment and main formation pathway of nitrate aerosols in China are not yet fully understood. In this study, PM2.5 samples were collected in Shanghai in the summer and winter of 2019. Water-soluble inorganic ions and isotopic signatures of stable nitrogen (δ15N-NO3-) and stable oxygen (δ18O-NO3-) in PM2.5 were determined. The results showed that NO3- was less important in summer (NO3-/SO42- = 0.4 ± 0.8), while it became the dominant species in winter (52.1 %). The average values of δ15N-NO3- and δ18O-NO3- in summer were + 2.0 ± 6.1 ‰ and 63.3 ± 9.4 ‰ respectively, which were significantly lower than those in winter (+7.2 ± 3.4 ‰ and 88.3 ± 12.1 ‰), indicating discrepancies between NOx sources and nitrate formation pathways. Both δ15N-NO3- and δ18O-NO3- were elevated at night, demonstrating that N2O5 hydrolysis contributed to the nocturnal nitrate increase even in summer. The contribution of the OH oxidation pathway to nitrate aerosols averaged at 70.5 ± 17.0 % in summer and N2O5 hydrolysis dominated the nitrate production in winter (approximately 80 %). On average, vehicle exhaust, coal combustion, natural gas burning, and soil emission contributed 50.7 %, 21.5 %, 15.9 %, and 11.9 %, respectively, to nitrate aerosols in summer, and contributed 56.8 %, 23.9 %, 13.6 %, and 5.7 %, respectively, to nitrate production in winter. Notably, natural gas burning is a non-negligible source of nitrate aerosols in Shanghai. In contrast to an inverse correlation between δ15N-NO3- and PM2.5, the value of δ18O-NO3- was positively correlated with nitrate concentration and aerosol liquid water content (ALWC) in winter, suggesting that explosive growth of nitrate was driven by continuous accumulation of N-depleted NOx and rapid N2O5 hydrolysis under calm and humid conditions. To continuously improve air quality, priority control should be given to vehicle emissions as the dominant source of NOx and volatile organic compounds (VOCs) in Shanghai.
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Affiliation(s)
- Weijie Huang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xingnan Ye
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China; Institute of Eco-Chongming (IEC), Chongming District, Shanghai 202162, China.
| | - Zhixiao Lv
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Yinghui Yao
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Yanan Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Yuanqiao Zhou
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China; Institute of Eco-Chongming (IEC), Chongming District, Shanghai 202162, China
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Kamezaki K, Maeda T, Ishidoya S, Tsukasaki A, Murayama S, Kaneyasu N. Low blank sampling method for measurement of the nitrogen isotopic composition of atmospheric NOx. PLoS One 2024; 19:e0298539. [PMID: 38422085 PMCID: PMC10903869 DOI: 10.1371/journal.pone.0298539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/25/2024] [Indexed: 03/02/2024] Open
Abstract
The nitrogen isotopic composition of nitrogen oxide (NOx) is useful for estimating its sources and sinks. Several methods have been developed to convert atmospheric nitric oxide (NO) and/or nitrogen dioxide (NO2) to nitrites and/or nitrates for collection. However, the collection efficiency and blanks are poorly evaluated for many collection methods. Here, we present a method for collecting ambient NOx (NO and NO2 simultaneously) with over 90% efficiency collection of NOx and low blank (approximately 0.5 μM) using a 3 wt% hydrogen peroxide (H2O2) and 0.5 M sodium hydride (NaOH) solution. The 1σ uncertainty of the nitrogen isotopic composition was ± 1.2 ‰. The advantages of this method include its portability, simplicity, and the ability to collect the required amount of sample to analyze the nitrogen isotopic composition of ambient NOx in a short period of time. Using this method, we observed the nitrogen isotopic compositions of NOx at the Tsukuba and Yoyogi sites in Japan. The averaged δ15N(NOx) value and standard deviation (1σ) in the Yoyogi site was (-2.7 ± 1.8) ‰ and in the Tsukuba site was (-1.7 ± 0.9) ‰ during the sampling period. The main NOx source appears to be the vehicle exhaust in the two sites.
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Affiliation(s)
- Kazuki Kamezaki
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (EMRI/AIST), Tsukuba, Japan
| | - Takahisa Maeda
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (EMRI/AIST), Tsukuba, Japan
| | - Shigeyuki Ishidoya
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (EMRI/AIST), Tsukuba, Japan
| | - Ayumi Tsukasaki
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (EMRI/AIST), Tsukuba, Japan
| | - Shohei Murayama
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (EMRI/AIST), Tsukuba, Japan
| | - Naoki Kaneyasu
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (EMRI/AIST), Tsukuba, Japan
- Fukushima Institute for Research, Education and Innovation, Namie-machi, Fukushima, Japan
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5
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Luo L, Wu S, Zhang R, Wu Y, Li J, Kao SJ. What controls aerosol δ 15N-NO 3-? NO x emission sources vs. nitrogen isotope fractionation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 871:162185. [PMID: 36775154 DOI: 10.1016/j.scitotenv.2023.162185] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 01/04/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Atmospheric δ15N-NO3- has been used to reveal NOx (NO + NO2) sources as NO3- is the ultimate sink of NOx. However, it remains questionable whether the nitrogen isotope fractionation among NOy (NO, NO2, NO3, N2O5, HNO3 and NO3-) engender the misjudgment of NOx emission sources by affecting δ15N-NOy. To explore this issue, we integrated the dataset of aerosol δ15N-NO3- values and ratios of fNO2 (fNO2 = NO2/(NO2 + NO)), calculated the nitrogen isotope fractionation factors (Δs) among NOy, compared the total energy consumption in Beijing-Tianjin-Hebei region (BTH) from 2013 to 2018. Results showed that, although the total energy consumption structure changed from 2013 to 2018 in BTH, there were fewer interannual variances of aerosol δ15N-NO3- values. Nitrogen isotope fractionation factors between NO and NO2 (Δ0), NO2 and NO3 (Δ2), NO2 and N2O5 (Δ3), NO2 and ClONO2 (Δ4) also displayed less interannual variations from 2013 to 2018 in BTH. But both aerosol δ15N-NO3- and Δs displayed significant seasonal patterns, and there was significant relationship between monthly aerosol δ15N-NO3- and Δs, which suggested that Δs have important influence on shaping aerosol δ15N-NO3- and further discriminating NOx emission sources. This study implies that we should refine the Δs when employing atmospheric δ15N-NO3- to quantify NOx source allocation.
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Affiliation(s)
- Li Luo
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China; Collaborative Innovation Center of Marine Science and Technology, Hainan University, Haikou 570228, China.
| | - Siqi Wu
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China
| | - Renjian Zhang
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yunfei Wu
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Jiawei Li
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Shuh-Ji Kao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; Collaborative Innovation Center of Marine Science and Technology, Hainan University, Haikou 570228, China
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6
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Zeng J, Han G, Zhang S, Qu R. Nitrate dynamics and source identification of rainwater in Beijing during rainy season: Insight from dual isotopes and Bayesian model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159234. [PMID: 36208764 DOI: 10.1016/j.scitotenv.2022.159234] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Anthropogenic reactive nitrogen emissions have a significant impact on atmospheric chemical composition and earth surface ecosystem. As one of the most important sinks of atmospheric nitrogen, the wet deposition of nitrate (rainwater NO3-) has been widely concerned. Yet, the sources and transformation processes of wet deposited NO3- were not well revealed in megacity during rainy season in the context of global climate change. Here, we investigated the concentrations of nitrogen components and dual isotopes of rainwater nitrate collected in Beijing during July to August 2021 (rainy season). The main findings showed that the concentrations of NH4+-N, NO3--N, and NO2--N ranged 0.5- 6.7 mg L-1, 0.3- 4.5 mg L-1, and 0.05- 0.18 mg L-1, respectively, with the average relative percentages of 69 %, 29 %, and 2 %. The stoichiometry analysis of characteristic ion ratios indicated that the contribution of municipal wastes and agricultural sources to rainwater NH4+-N is relatively significant, while traffics were the major contributor of NO3--N instead of the fixed emission. Rainwater δ15N-NO3- and δ18O-NO3- presented slightly 15N-depleted characteristic compared to previous studies with the average values of -3.9 ± 3.1 ‰ and 58.7 ± 12.6 ‰. These isotope compositions suggesting an origin of rainwater NO3- from the mixing of multi-sources and was mainly generated via the pathway of OH radical oxidization. Further source apportionment of rainwater NO3- by Bayesian mixing model evaluated that traffic (30.3 %) and soil (30.3 %) emissions contributed mostly to NO3-, while the contribution of biomass burning (18.8 %) and coal combustion (20.6 %) were relatively lower. This study highlighted the important role of dual isotopes in rainwater nitrate source identification and formation processes in megacity.
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Affiliation(s)
- Jie Zeng
- Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China
| | - Guilin Han
- Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China.
| | - Shitong Zhang
- Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China
| | - Rui Qu
- Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China
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Application of Stable Isotope Techniques in Tracing the Sources of Atmospheric NOX and Nitrate. Processes (Basel) 2022. [DOI: 10.3390/pr10122549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Nitrate is an important component of PM2.5, and its dry deposition and wet deposition can have an impact on ecosystems. Nitrate in the atmosphere is mainly transformed by nitrogen oxides (NOX = NO + NO2) through a number of photochemical processes. For effective management of the atmosphere’s environment, it is crucial to understand the sources of atmospheric NOX and the processes that produce atmospheric nitrate. The stable isotope method is an effective analytical method for exploring the sources of NO3− in the atmosphere. This study discusses the range and causes of δ15N data from various sources of NOX emissions, provides the concepts of stable isotope techniques applied to NOX traceability, and introduces the use of Bayesian mixture models for the investigation of NOX sources. The combined application of δ15N and δ18O to determine the pathways of nitrate formation is summarized, and the contribution of Δ17O to the atmospheric nitrate formation pathway and the progress of combining Δ17O simulations to reveal the atmospheric oxidation characteristics of different regions are discussed, respectively. This paper highlights the application results and development trend of stable isotope techniques in nitrate traceability, discusses the advantages and disadvantages of stable isotope techniques in atmospheric NOX traceability, and looks forward to its future application in atmospheric nitrate pollution. The research results could provide data support for regional air pollution control measures.
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Zhou T, Jiang Z, Zhou J, Zhao W, Wu Y, Yu H, Li W, Zhang Z, Su G, Ma T, Geng L. Fast and Efficient Atmospheric NO 2 Collection for Isotopic Analysis by a 3D-Printed Denuder System. Anal Chem 2022; 94:13215-13222. [PMID: 36098995 DOI: 10.1021/acs.analchem.2c02839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Being major species of atmospheric reactive nitrogen, nitrogen oxides (NOx = NO + NO2) have important implications for ozone and OH radical formation in addition to nitrogen cycles. Stable nitrogen isotopes (δ15N) of NOx have been sought to track NOx emissions and NOx chemical reactivities in the atmosphere. The current atmospheric NOx collection methods for isotopic analysis, however, largely suffer from unverified collection efficiency and/or low collection speed (<10 L/min). The latter makes it difficult to study δ15N(NOx) in pristine regions with low NOx concentrations. Here, we present a three-dimensional (3D)-printed honeycomb denuder (3DP-HCD) system, which can effectively collect atmospheric NO2 (a major part of NOx) under a variety of laboratory and field conditions. With a coating solution consisting of 10% potassium hydroxide (KOH) and 25% guaiacol in methanol, the denuder system can collect NO2 with nearly 100% efficiency at flow rates of up to 70 L/min, which is 7 times higher than that of the existing method and allows high-resolution (e.g., diurnal or finer resolution) NO2 collection even in pristine sites. Besides, the δ15N of NO2 collected by the 3DP-HCD system shows good reproducibility and consistency with the previously tested method. Preliminary results of online NO oxidation by a chrome trioxide (CrO3) oxidizer for simultaneous NO and NO2 collection are also presented and discussed.
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Affiliation(s)
- Tao Zhou
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China.,Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Zhuang Jiang
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Jiacheng Zhou
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei 230031, Anhui, China.,University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Weixiong Zhao
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Yichao Wu
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Hui Yu
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei 230031, Anhui, China.,University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Weikun Li
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Zhongyi Zhang
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Guangming Su
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Tianming Ma
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China.,Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Lei Geng
- Stable Isotope Laboratory of Ice Core and Atmospheric Chemistry, School of Earth and Spaces Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China.,CAS Center for Excellence in Comparative Planetology, University of Science and Technology of China, Hefei 230026, Anhui, China
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9
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Dong X, Guo Q, Han X, Wei R, Tao Z. The isotopic patterns and source apportionment of nitrate and ammonium in atmospheric aerosol. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 803:149559. [PMID: 34500264 DOI: 10.1016/j.scitotenv.2021.149559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/20/2021] [Accepted: 08/05/2021] [Indexed: 06/13/2023]
Abstract
Nitrate (NO3-) and ammonium (NH4+) are the major components in inorganic aerosol. However, their sources and formation processes remain unclear. This study conducted a year-round field measurement of TSP, PM2.5 and PM1.0 in five different sites in the Beijing-Tianjin-Hebei (BTH) region to determine the concentrations of water-soluble inorganic ions (WSIIs) and the isotopic compositions of inorganic nitrogen (δ15N-NH4+, δ15N-NO3-, and δ18O-NO3-). The results showed the highest concentration of WSIIs in winter and lowest in summer. δ15N-NO3-, δ18O-NO3-, and δ15N-NH4+ were in the range of -6.1-18.2, 52.2-103.8, and -28.7-36.2‰, respectively. The seasonal variations of δ15N-NO3- and δ15N-NH4+ were an indication of relative contributions of the main sources and effects of meteorological conditions. The source apportionment identified fossil fuel combustion (38.2-50.6%), agricultural emissions (18-24.7%), biomass burning (16.3-22.7%), and road dust/soil (8.7-23.4%) were the main sources of inorganic aerosols. The local sources and regional migration contributed to the level of inorganic aerosol pollution. In winter, the aerosol in the BTH region was affected by the air mass from the northwest. While in spring and summer, the air mass was mainly from the South China. The low temperature and high relative humidity favored to the formation of inorganic nitrogen aerosol, and solar radiation affected the formation processes of inorganic aerosols by changing the oxidation pathway of NO3- and accelerating the volatilization and dissociation of ammonium nitrate (NH4NO3). This study discovered the main source contributions of inorganic nitrogen aerosol using N and O isotopes composition, and the obtained information has a great importance in understanding the effects of meteorological conditions on formation and the contribution of regional transport.
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Affiliation(s)
- Xinyuan Dong
- Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingjun Guo
- Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China.
| | - Xiaokun Han
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Rongfei Wei
- Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhenghua Tao
- Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Wu C, Liu L, Wang G, Zhang S, Li G, Lv S, Li J, Wang F, Meng J, Zeng Y. Important contribution of N 2O 5 hydrolysis to the daytime nitrate in Xi'an, China during haze periods: Isotopic analysis and WRF-Chem model simulation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117712. [PMID: 34246996 DOI: 10.1016/j.envpol.2021.117712] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/25/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
Nitrate, as one of the major components of tropospheric aerosols, plays a crucial role in winter haze formation. While, the formation mechanism of the high production of nitrate in Chinese megacities is still not fully understood. To quantify the contributions of major formation pathways to nitrate, airborne particles in Xi'an, inland China during the winter of 2017 were measured and analyzed for the water-soluble ions and stable nitrogen/oxygen isotope compositions of nitrate in PM2.5, followed by a WRF-Chem model simulation. The oxygen isotopic results indicated that N2O5 hydrolysis was an important formation pathway for the daytime nitrate in the haze episodes. The model simulation further revealed that N2O5 hydrolysis contribution increased from 8.2% to 20.5% of the total nitrate over 14:00-16:00 p.m., clearly showing that N2O5 formation followed by a heterogeneous hydrolysis to nitrate can effectively proceed in daytime under the abundantly co-existing O3, NO2 and NH3 conditions.
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Affiliation(s)
- Can Wu
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 210062, China
| | - Lang Liu
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; School of Public Policy and Administration, Northwestern Polytechnical University, Xi'an, 710061, China
| | - Gehui Wang
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 210062, China; Institute of Eco-Chongming, 3663 North Zhongshan Road, Shanghai, 200062, China.
| | - Si Zhang
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 210062, China
| | - Guohui Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China
| | - Shaojun Lv
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 210062, China
| | - Jianjun Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China
| | - Fanglin Wang
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 210062, China
| | - Jingjing Meng
- School of Environment and Planning, Liaocheng University, Liaocheng, 252000, China
| | - Ying Zeng
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 210062, China
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11
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Kim Y, Lee I, Farquhar J, Kang J, Villa IM, Kim H. Multi isotope systematics of precipitation to trace the sources of air pollutants in Seoul, Korea. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 286:117548. [PMID: 34438485 DOI: 10.1016/j.envpol.2021.117548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/27/2021] [Accepted: 06/04/2021] [Indexed: 06/13/2023]
Abstract
Multiple sulfur (δ34Ssulfate, Δ33Ssulfate, & Δ36Ssulfate), nitrogen and oxygen (δ15Nnitrate & δ18Onitrate) and strontium (87Sr/86Sr) isotope compositions of precipitation collected from Seoul, South Korea were analyzed to study the sources, transportation and deposition of air pollutants in East Asia. The δ34Ssulfate values (from 1.9 to 14.6‰ with a median of 4.7‰) and the δ15Nnitrate values (from -2.0 to 13.3‰ with a median of 1.0‰) suggest that fossil fuel use (emission from coal combustion and vehicle exhaust) is a predominant source for sulfur and nitrogen, but other natural sources including biogenic contributions of DMS also add to their total budget. The seasonal variations are observed in δ34Ssulfate and δ15Nnitrate values (both higher in winter season), which is likely to result from the increase of coal use for domestic heating in China. The δ18Onitrate values also varied seasonally depending on the NOx oxidation pathway, being about 20‰ higher in winter than in summer season. The Δ33Ssulfate and Δ36Ssulfate values are not anomalous, showing the absence of MIF signals in precipitation of Seoul. The 87Sr/86Sr ratio of the precipitation samples range from 0.70988 to 0.71487 with a median of 0.71073, indicating the influence of at least three end-member (silicate dust, carbonate dust and anthropogenic emission). Ionic ratios such as (K++NH4+)/(Ca2++Mg2+) and Cl-/Na+ suggest the overwhelming effect of anthropogenic input rather than carbonate dust on the end-member with lower 87Sr/86Sr ratios.
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Affiliation(s)
- Yeongmin Kim
- Research Center for Geochronology and Isotope Analysis, Korea Basic Science Institute, Cheongju, 28119, Republic of Korea
| | - Insung Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
| | - James Farquhar
- Department of Geology, University of Maryland, College Park, MD, 20742, USA
| | - Jisuk Kang
- Institute of Geological Sciences, University of Bern, Baltzerstrasse 3, CH-3012, Bern, Switzerland
| | - Igor M Villa
- Institute of Geological Sciences, University of Bern, Baltzerstrasse 3, CH-3012, Bern, Switzerland; Centro Universitario Datazioni e Archeometria, Università di Milano Bicocca, 20126, Milano, Italy
| | - Hyoungbum Kim
- Department of Earth Science Education, Chungbuk National University, Cheongju, 28644, Republic of Korea
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12
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Song W, Liu XY, Hu CC, Chen GY, Liu XJ, Walters WW, Michalski G, Liu CQ. Important contributions of non-fossil fuel nitrogen oxides emissions. Nat Commun 2021; 12:243. [PMID: 33431857 PMCID: PMC7801390 DOI: 10.1038/s41467-020-20356-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 11/24/2020] [Indexed: 11/13/2022] Open
Abstract
Since the industrial revolution, it has been assumed that fossil-fuel combustions dominate increasing nitrogen oxide (NOx) emissions. However, it remains uncertain to the actual contribution of the non-fossil fuel NOx to total NOx emissions. Natural N isotopes of NO3− in precipitation (δ15Nw-NO3−) have been widely employed for tracing atmospheric NOx sources. Here, we compiled global δ15Nw-NO3− observations to evaluate the relative importance of fossil and non-fossil fuel NOx emissions. We found that regional differences in human activities directly influenced spatial-temporal patterns of δ15Nw-NO3− variations. Further, isotope mass-balance and bottom-up calculations suggest that the non-fossil fuel NOx accounts for 55 ± 7% of total NOx emissions, reaching up to 21.6 ± 16.6Mt yr−1 in East Asia, 7.4 ± 5.5Mt yr−1 in Europe, and 21.8 ± 18.5Mt yr−1 in North America, respectively. These results reveal the importance of non-fossil fuel NOx emissions and provide direct evidence for making strategies on mitigating atmospheric NOx pollution. This study investigates in the importance of non-fossil fuel NOx emissions in the surface-earth-nitrogen cycle. The study shows how changes of regional human activities directly influence δ15N signatures of deposited NOx to terrestrial environments and that emissions have largely been underestimated.
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Affiliation(s)
- Wei Song
- School of Earth System Science, Tianjin University, 300072, Tianjin, China
| | - Xue-Yan Liu
- School of Earth System Science, Tianjin University, 300072, Tianjin, China.
| | - Chao-Chen Hu
- School of Earth System Science, Tianjin University, 300072, Tianjin, China
| | - Guan-Yi Chen
- Georgia Tech Shenzhen Institute, Tianjin University, 518071, Shenzhen, China
| | - Xue-Jun Liu
- College of Resources and Environmental Sciences, China Agricultural University, 100193, Beijing, China
| | - Wendell W Walters
- Institute at Brown for Environment and Society, Brown University, 85 Waterman St, Providence, RI, 02912, USA
| | - Greg Michalski
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN, 47907, USA
| | - Cong-Qiang Liu
- School of Earth System Science, Tianjin University, 300072, Tianjin, China
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13
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Luo L, Zhu RG, Song CB, Peng JF, Guo W, Liu Y, Zheng N, Xiao H, Xiao HY. Changes in nitrate accumulation mechanisms as PM 2.5 levels increase on the North China Plain: A perspective from the dual isotopic compositions of nitrate. CHEMOSPHERE 2021; 263:127915. [PMID: 33297012 DOI: 10.1016/j.chemosphere.2020.127915] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/02/2020] [Accepted: 08/03/2020] [Indexed: 06/12/2023]
Abstract
Nitrate (NO3-) has become recognized as the most important water-soluble ion in fine particulate (PM2.5), and has been proposed as a driving factor for regional haze formation. However, nitrate formation mechanisms are still poorly understood. In this study, PM2.5 samples were collected from September 2017 to August 2018 in Shijiazhuang, a city located on the North China Plain, and NO3-concentration, δ18O-NO3- and δ15N-NO3- values in PM2.5 were analyzed. NO3- concentrations increased as PM2.5 levels increased during both polluted and non-polluted days over the entire year. δ18O-NO3- values during cold months (63.5-103‰) were higher than those during warm months (50.3-85.4‰), these results suggested that the nitrate formation pathways shifted from the NO2 + OH (POH) in warm months to the N2O5 + H2O (PN2O5) and NO3 + VOCs (PNO3) pathways in cold months. Especially during cold months, δ18O-NO3- values increased from 65.2-79.9‰ to 80.7-96.2‰ when PM2.5 increased from ∼25 to >100 μg/m3, but when PM2.5 > 100 μg/m3, there were relatively small variations in δ18O-NO3-. These results suggested that nitrate formation pathways changed from POH to PN2O5 and PNO3 pathways when PM2.5 < 100 μg/m3, but that PN2O5 and PNO3 dominated nitrate production when PM2.5 > 100 μg/m3. Higher δ15N-NO3- values in warm months (-11.8-13.8‰) than in cold months (-0.7-22.6‰) may be attributed to differences in NOx emission sources and nitrogen isotopic fractionation among NOx and NO3-. These results provide information on the dual isotopic compositions of nitrate to understand nitrate formation pathways under different PM2.5 levels.
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Affiliation(s)
- Li Luo
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang, 330013, China
| | - Ren-Guo Zhu
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang, 330013, China
| | - Cong-Bo Song
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Jian-Fei Peng
- China Center for Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Wei Guo
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang, 330013, China
| | - Yonghui Liu
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang, 330013, China
| | - Nengjian Zheng
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang, 330013, China
| | - Hongwei Xiao
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang, 330013, China.
| | - Hua-Yun Xiao
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang, 330013, China.
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14
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Wang K, Hattori S, Kang S, Lin M, Yoshida N. Isotopic constraints on the formation pathways and sources of atmospheric nitrate in the Mt. Everest region. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:115274. [PMID: 32891045 DOI: 10.1016/j.envpol.2020.115274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Inorganic particulate nitrate (p-NO3-), gaseous nitric acid (HNO3(g)) and nitrogen oxides (NOx = NO + NO2), as main atmospheric pollutants, have detrimental effects on human health and aquatic/terrestrial ecosystems. Referred to as the 'Third Pole' and the 'Water Tower of Asia', the Tibetan Plateau (TP) has attracted wide attention on its environmental changes. Here, we evaluated the oxidation processes of atmospheric nitrate as well as traced its potential sources by analyzing the isotopic compositions of nitrate (δ15N, δ18O, and Δ17O) in the aerosols collected from the Mt. Everest region during April to September 2018. Over the entire sampling campaigns, the average of δ15N(NO3-), δ18O(NO3-), and Δ17O(NO3-) was -5.1 ± 2.3‰, 66.7 ± 10.2‰, and 24.1 ± 3.9‰, respectively. The seasonal variation in Δ17O(NO3-) indicates the relative importance of O3 and HO2/RO2/OH in NOx oxidation processes among different seasons. A significant correlation between NO3- and Ca2+ and frequent dust storms in the Mt. Everest region indicate that initially, the atmospheric nitrate in this region might have undergone a process of settling; subsequently, it got re-suspended in the dust. Compared with the Δ17O(NO3-) values in the northern TP, our observed significantly higher values suggest that spatial variations in atmospheric Δ17O(NO3-) exist within the TP, and this might result from the spatial variations of the atmospheric O3 levels, especially the stratospheric O3, over the TP. The observed δ15N(NO3-) values predicted remarkably low δ15N values in the NOx of the sources and the N isotopic fractionation plays a crucial role in the seasonal changes of δ15N(NO3-). Combined with the results from the backward trajectory analysis of air mass, we suggest that the vehicle exhausts and agricultural activities in South Asia play a dominant role in determining the nitrate levels in the Mt. Everest region.
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Affiliation(s)
- Kun Wang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science (CAS), Lanzhou, 730000, China; Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shohei Hattori
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science (CAS), Lanzhou, 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Mang Lin
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan; State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, CAS, Guangzhou, 510640, China
| | - Naohiro Yoshida
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan; Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8551, Japan
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15
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Lim S, Yang X, Lee M, Li G, Gao Y, Shang X, Zhang K, Czimczik CI, Xu X, Bae MS, Moon KJ, Jeon K. Fossil-driven secondary inorganic PM 2.5 enhancement in the North China Plain: Evidence from carbon and nitrogen isotopes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115163. [PMID: 32682020 DOI: 10.1016/j.envpol.2020.115163] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 07/01/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
Measuring isotopic ratios in aerosol particles is a powerful tool for identifying major sources, particularly in separating fossil from non-fossil sources and investigating aerosol formation processes. We measured the radiocarbon, stable carbon, and stable nitrogen isotopic composition of PM2.5 in Beijing (BJ) and Changdao (CD) in the North China Plain (NCP) from May to mid-June 2016. The mean PM2.5 concentrations were 48.6 ± 28.2 μg m-3 and 71.2 ± 29.0 μg m-3 in BJ and CD, respectively, with a high contribution (∼66%) from secondary inorganic aerosol (SIA; NO3-, NH4+, and SO42-). The mean δ13C of total carbon (TC) and δ15N of total nitrogen (TN) values differed significantly between the two sites (p-value of <0.001): -25.1 ± 0.3‰ in BJ and -24.5 ± 0.4‰ in CD and 10.6 ± 1.8‰ in BJ and 5.0 ± 3.1‰ in CD, respectively. In BJ, the average δ15N (NH4+) and δ15N (NO3-) values were 12.9 ± 2.3‰ and 5.2 ± 3.5‰, respectively. The ionic molar ratios and isotopic ratios suggest that NO3- in BJ was formed through the phase-equilibrium reaction of NH4NO3 under sufficient NH3 (g) conditions, promoted by fossil-derived NH3 (g) transported with southerly winds. In BJ, fossil fuel sources comprised 52 ± 7% of TC and 45 ± 28% of NH4+ on average, estimated from radiocarbon (14C) analysis and the δ15N and isotope mixing model, respectively. These multiple-isotopic composition results emphasize that PM2.5 enhancement is derived from fossil sources, in which vehicle emissions are a key contributor. The impact of the coal source was sporadically noticeable. Under regional influences, the fossil fuel-driven SIA led to the PM2.5 enhancements. Our findings demonstrate that the multiple-isotope approach is highly advantageous to elucidate the key sources and limiting factors of secondary inorganic PM2.5 aerosols.
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Affiliation(s)
- Saehee Lim
- Dept. of Earth and Environmental Sciences, Korea University, 02841, Seoul, South Korea
| | - Xiaoyang Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Meehye Lee
- Dept. of Earth and Environmental Sciences, Korea University, 02841, Seoul, South Korea.
| | - Gang Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yuanguan Gao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Xiaona Shang
- Dept. of Earth and Environmental Sciences, Korea University, 02841, Seoul, South Korea
| | - Kai Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Claudia I Czimczik
- Dept. of Earth System Science, University of California, 92697, Irvine, USA
| | - Xiaomei Xu
- Dept. of Earth System Science, University of California, 92697, Irvine, USA
| | - Min-Suk Bae
- Environmental Engineering Department, Mokpo National University, 58554, Muan, South Korea
| | - Kwang-Joo Moon
- National Institute of Environmental Research, 22689, Incheon, South Korea
| | - Kwonho Jeon
- National Institute of Environmental Research, 22689, Incheon, South Korea
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16
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Li Z, Hastings MG, Walters WW, Tian L, Clemens SC, Song L, Shao L, Fang Y. Isotopic evidence that recent agriculture overprints climate variability in nitrogen deposition to the Tibetan Plateau. ENVIRONMENT INTERNATIONAL 2020; 138:105614. [PMID: 32155512 DOI: 10.1016/j.envint.2020.105614] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/08/2020] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
The stable isotopes of nitrogen in nitrate archived in polar ice have been interpreted as reflecting a shift in reactive nitrogen sources or changes in atmospheric chemical reactivity. Here, we present a novel concentration and isotopic record of nitrate (δ15N-NO3-) from a central Tibetan Plateau ice core over the last ~200 years. We find that nitrate concentration increased from 6.0 ± 2.3 μeq/L (mean ± 1σ) in the preindustrial period (prior to 1900s) to 7.3 ± 2.7 μeq/L in post-1950. Over the same time period, the δ15N-NO3- decreased from 8.7 ± 3.7‰ to 4.2 ± 3.1‰, with much larger interannual variation in δ15N-NO3- during the preindustrial period. We present a useful framework for quantifying the sensitivity of the isotopic composition of atmospheric nitrate to changes in both sources and chemistry (gas and aerosol phase). After 1950, nitrogen deposition is primarily driven by fertilizer use, leading to significant increases in concentration and decreases in δ15N-NO3-. The large interannual variability of ice core δ15N-NO3- in the preindustrial reflects natural processes, namely the El Niño Southern Oscillation (ENSO) and dust events. Our results highlight a new connection between the nitrogen cycle and ENSO, and the overprinting of natural climate signals by recent anthropogenic increases in reactive nitrogen release.
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Affiliation(s)
- Zhengjie Li
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China; Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China
| | - Meredith G Hastings
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA; Institute at Brown for Environment and Society, Brown University, Providence, Rhode Island 02912, USA.
| | - Wendell W Walters
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA; Institute at Brown for Environment and Society, Brown University, Providence, Rhode Island 02912, USA
| | - Lide Tian
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming, Yunnan 650500, China; Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS), Beijing 100101, China
| | - Steven C Clemens
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA
| | - Linlin Song
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China
| | - Lili Shao
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming, Yunnan 650500, China
| | - Yunting Fang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China; Qingyuan Forest CERN, Shenyang, Liaoning 110016, China; Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China.
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17
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He P, Xie Z, Yu X, Wang L, Kang H, Yue F. The observation of isotopic compositions of atmospheric nitrate in Shanghai China and its implication for reactive nitrogen chemistry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 714:136727. [PMID: 31981873 DOI: 10.1016/j.scitotenv.2020.136727] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 06/10/2023]
Abstract
The occurrence of PM2.5 pollution in China is usually associated with the formation of atmospheric nitrate, the oxidation product of nitrogen oxides (NOX = NO + NO2). The oxygen-17 excess of nitrate (Δ17O(NO3-)) can be used to reveal the relative importance of nitrate formation pathways and get more insight into reactive nitrogen chemistry. Here we present the observation of isotopic composition of atmospheric nitrate (Δ17O and δ15N) collected from January to June 2016 in Shanghai China. Concentrations of atmospheric nitrate ranged from 1.4 to 24.1 μg m-3 with the mean values being (7.6 ± 4.4 (1SD)), (10.2 ± 5.8) and (4.1 ± 2.4) μg m-3 in winter, spring and summer respectively. Δ17O(NO3-) varied from 20.5‰ to 31.9‰ with the mean value being (26.9 ± 2.8) ‰ in winter, followed by (26.6 ± 1.7) ‰ in spring and the lowest (23.2 ± 1.6) ‰ in summer. Δ17O(NO3-)-constrained estimates suggest that the conversion of NOX to nitrate is dominated by NO2 + OH and/or NO2 + H2O, with the mean possible contribution of 55-77% in total and even higher (84-92%) in summer. A diurnal variation of Δ17O(NO3-) featured by high values at daytime (28.6 ± 1.2‰) and low values (25.4 ± 2.8‰) at nighttime was observed during our diurnal sampling period. This trend is related to the atmospheric life of nitrate (τ) and calculations indicate τ is around 15 h during the diurnal sampling period. In terms of δ15N(NO3-), it changed largely in our observation, from -2.9‰ to 18.1‰ with a mean of (6.4 ± 4.4) ‰. Correlation analysis implies that the combined effect of NOX emission sources and isotopic fractionation processes are responsible for δ15N(NO3-) variations. Our observations with the aid of model simulation in future study will further improve the understanding of reactive nitrogen chemistry in urban regions.
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Affiliation(s)
- Pengzhen He
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; School of Environment and Tourism, West Anhui University, Lu'an, Anhui 237012, China; Anhui Province Key Laboratory of Polar Environment and Global Change, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhouqing Xie
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, China; Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, Anhui 230031, China; Anhui Province Key Laboratory of Polar Environment and Global Change, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xiawei Yu
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; Anhui Province Key Laboratory of Polar Environment and Global Change, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Longquan Wang
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; Anhui Province Key Laboratory of Polar Environment and Global Change, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Hui Kang
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; Anhui Province Key Laboratory of Polar Environment and Global Change, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Fange Yue
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; Anhui Province Key Laboratory of Polar Environment and Global Change, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
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18
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Li C, Li SL, Yue FJ, He SN, Shi ZB, Di CL, Liu CQ. Nitrate sources and formation of rainwater constrained by dual isotopes in Southeast Asia: Example from Singapore. CHEMOSPHERE 2020; 241:125024. [PMID: 31604191 DOI: 10.1016/j.chemosphere.2019.125024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/29/2019] [Accepted: 09/30/2019] [Indexed: 06/10/2023]
Abstract
Emission of reactive nitrogen species has a major impact on atmospheric chemistry, ecosystem and human health. The origin and formation mechanisms of wet-deposited nitrate are not well understood in Southeast Asia (SEA). In this study, we measured stable isotopes of nitrate (δ15N and δ18O) and chemical compositions of daily rainwater from May 2015 to July 2017 in Singapore. Our results showed that δ15N-NO3- and δ18O-NO3- varied seasonally with higher values during the Inter-monsoon period (April-May and October-November) than during Northeast (December-March) and Southwest monsoon (June-September). Bayesian mixing modeling, which took account of the isotope fractionation, indicated that traffic emission (47 ± 32%) and lightning (19 ± 20%) contributed the most to NO3- with increased traffic contribution (55 ± 37%) in the Northeast monsoon and lightning (24 ± 23%) during the Inter-monsoon period. Biomass burning and coal combustion, likely from transboundary transport, contributed ∼25% of nitrate in the rainwater. Monte Carlo simulation of δ18O-NO3- indicated that oxidation process by hydroxyl radical contributed 65 ± 14% of NO3-, with the rest from hydrolysis of N2O5. Wind speed had large effect on δ18O-NO3- variations in the atmosphere with more involvement of hydroxyl radical reactions when wind speed increased. Our study highlights the key role of isotopic fractionation in nitrate source apportionment, and the influence of meteorological conditions on nitrate formation processes in SEA.
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Affiliation(s)
- Cai Li
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; School of Urban and Environmental Science, Huaiyin Normal University, Huai'an, 223300, China
| | - Si-Liang Li
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China.
| | - Fu-Jun Yue
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - Shao-Neng He
- Earth Observatory of Singapore, Nanyang Technological University, Singapore, 639798, Singapore.
| | - Zong-Bo Shi
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Chong-Li Di
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Cong-Qiang Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
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19
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Song W, Liu XY, Wang YL, Tong YD, Bai ZP, Liu CQ. Nitrogen isotope differences between atmospheric nitrate and corresponding nitrogen oxides: A new constraint using oxygen isotopes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 701:134515. [PMID: 31734482 DOI: 10.1016/j.scitotenv.2019.134515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/03/2019] [Accepted: 09/16/2019] [Indexed: 06/10/2023]
Abstract
Tracking of reactive nitrogen (N) sources is important for the effective mitigation of N emissions. By combining the N and oxygen (O) isotopes of atmospheric NO3-, stable isotope mixing models were recently applied to evaluate the relative contributions of major NOx sources. However, it has long been unresolved how to accurately constrain the δ15N differences between NO3- and corresponding NOx (ε(NO2→NO3-) values). Here, we first incorporated the HC oxidation (NO2 → NO3-) pathway by using Δ17O values to evaluate the ε(NO2→NO3-) values, performed on NO3- in PM2.5 collected during the day and at night from January 4-13, 2015 at an urban site in Beijing. We found that the Δ17O-based ε values (ε17O-based(NO2→NO3-)) (15.6 ± 7.4‰) differed distinctly from δ18O-based ε values (ε18O-based(NO2→NO3-)) (33.0 ± 9.5‰) so did not properly incorporate the isotopic effects of the HC oxidation (NO2 → NO3-) pathway. Based on the ε(NO2→NO3-) values, δ15N values of NOx from coal combustion (CC), vehicle exhausts (VE), biomass burning (BB), and the microbial N cycle (MC), as well as NO3- in PM2.5, we further quantified the source contributions by using Stable Isotope Analysis in R (the SIAR model). We found that the respective fractional contributions of CC-NOx and MC-NOx were underestimated by 64% and were overestimated by 216% by using ε18O-based(NO2→NO3-) values. We concluded that the new ε17O-based(NO2→NO3-) values reduced uncertainties in contribution analysis and the evaluation method for atmospheric NO3- sources.
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Affiliation(s)
- Wei Song
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Xue-Yan Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
| | - Yan-Li Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Chinese Academy for Environmental Planning, Beijing 100012, China
| | - Yin-Dong Tong
- College of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Zhi-Peng Bai
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Cong-Qiang Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
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20
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Hattori S, Nuñez Palma Y, Itoh Y, Kawasaki M, Fujihara Y, Takase K, Yoshida N. Isotopic evidence for seasonality of microbial internal nitrogen cycles in a temperate forested catchment with heavy snowfall. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 690:290-299. [PMID: 31291607 DOI: 10.1016/j.scitotenv.2019.06.507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/28/2019] [Accepted: 06/29/2019] [Indexed: 06/09/2023]
Abstract
The Hokuriku district of central Japan receives high levels of precipitation during winter, largely in the form of snow. This study aimed to elucidate the internal nitrogen dynamics in this temperate forested region with heavy snowfall using the triple oxygen and nitrogen isotopic compositions of NO3-. The isotopic compositions of NO3- in atmospheric depositions (P and Tf), with terrestrial components of the soil layer (A0, S25, S55, and S90), ground water (G), and output (St) were measured from 2015 to 2016 in a forested catchment located in the southern area of the Ishikawa Prefecture, Japan. Seasonal distributions of Δ17O(NO3-) showed a decreasing trend from the inputs to outputs of the ecosystem. We found relatively constant Δ17O(NO3-) values in the output components (G and St), but found highly fluctuating Δ17O(NO3-) values resulting from the seasonal variations in the nitrification activity within soil waters. Specifically, we observed a lower nitrifying activity in the top soil layer throughout cold periods, presumably due to the input of cold melted snow water. The general trend of increasing δ15N(NO3-) value from the input to output components, with the changes in denitrification hotspots from shallow to deeper soil layer, can be observed between warm and cold periods. Thus, the seasonal changes of hotspots related to microbial nitrification and denitrification could be noted due to the seasonal changes in the isotopic compositions of nitrate. The estimated ecosystem-scale gross nitrification and denitrification rates are low; however, the output components are relatively stable with low concentrations of nitrate, indicating that the plant uptake of nitrogen most probably occurs at greater rates and scales in this forested ecosystem. Future nitrogen deposition and the vulnerable dynamics of snow melting are likely to have impactful consequences on such localities.
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Affiliation(s)
- Shohei Hattori
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4529 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8502, Japan.
| | - Yoshio Nuñez Palma
- Department of Environmental Chemistry and Engineering, Interdisciplinary Graduate School of Science and Engineering and Engineering, Tokyo Institute of Technology, 4529 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8502, Japan
| | - Yuko Itoh
- Forestry and Forest Products Research Institute (FFPRI), 1 Matsunosato, Tsukuba, Ibaraki 305-8687, Japan
| | - Moeko Kawasaki
- Nakanoto General Agriculture and Forestry Office, Ishikawa Prefecture, 33 Ni-bu, Kojima-machi, Nanao, Ishikawa 926-0852, Japan
| | - Yoichi Fujihara
- Faculty of Bioresources and Environmental Sciences, Ishikawa Prefectural University, 1-308, Suematsu, Nonoichi, Ishikawa 921-8836, Japan
| | - Keiji Takase
- Faculty of Bioresources and Environmental Sciences, Ishikawa Prefectural University, 1-308, Suematsu, Nonoichi, Ishikawa 921-8836, Japan
| | - Naohiro Yoshida
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4529 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8502, Japan; Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan
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21
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Xia X, Li S, Wang F, Zhang S, Fang Y, Li J, Michalski G, Zhang L. Triple oxygen isotopic evidence for atmospheric nitrate and its application in source identification for river systems in the Qinghai-Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 688:270-280. [PMID: 31229824 DOI: 10.1016/j.scitotenv.2019.06.204] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/12/2019] [Accepted: 06/13/2019] [Indexed: 06/09/2023]
Abstract
Nitrate source identification in river systems is important for water quality management. Recently, the oxygen isotopic anomaly of nitrate in atmospheric deposition (Δ17Oatm) is used to identify unprocessed atmospheric nitrate in river systems to reduce the uncertainty caused by the wide range of δ18O. In high-elevation regions, such as the Qinghai-Tibetan Plateau (QTP) featured with lower temperature and pressure as well as strong radiation, the Δ17Oatm might be different from that in low-elevation regions, but no relevant studies have been reported. In this work, Δ17Oatm in the QTP was studied, and the fingerprints of nitrate isotopes in synthetic fertilizer, livestock manure, domestic sewage, and soil organic nitrogen (SON) were identified and used to quantify various source contributions to riverine nitrate in the Yellow River and Changjiang River source regions located in the QTP during 2016-2017. The results showed that the average of Δ17Oatm in the QTP was 16.4‰, lower than the range (19-30‰) reported for the low-elevation regions. The possible mechanism is decreased O3 as well as increased hydroxyl and peroxy radical levels in the troposphere caused by the climate condition and ozone valley in the QTP will affect the production pathways of atmospheric nitrate. By combining the sewage discharge data with the output results of the SIAR (stable isotope analysis in R) model based on the stable isotope data, manure was determined to be one of the major sources to riverine nitrate for both rivers. The contributions of various sources to riverine nitrate were 47 ± 10% for manure, 30 ± 5% for SON, 10 ± 4% for atmospheric precipitation, 9 ± 2% for synthetic fertilizer, and 4 ± 0% for sewage in the Yellow River source region. This study indicates that the unique atmospheric conditions in the QTP have led to a lower Δ17Oatm value, and atmospheric source makes a considerable contribution to riverine nitrate in the QTP.
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Affiliation(s)
- Xinghui Xia
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Siling Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Fan Wang
- Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou 51027, China
| | - Sibo Zhang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yunting Fang
- Institute of Applied Ecology, The Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
| | - Jianghanyang Li
- Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall, West Lafayette, IN 47907, USA
| | - Greg Michalski
- Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall, West Lafayette, IN 47907, USA
| | - Liwei Zhang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
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22
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Xu Y, Xiao H, Wu D. Traffic-related dustfall and NO x, but not NH 3, seriously affect nitrogen isotopic compositions in soil and plant tissues near the roadside. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 249:655-665. [PMID: 30933763 DOI: 10.1016/j.envpol.2019.03.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Ammonia (NH3) emissions from traffic have received particular attention in recent years because of their important contributions to the growth of secondary aerosols and the negative effects on urban air quality. However, few studies have been performed on the impacts of traffic NH3 emissions on adjacent soil and plants. Moreover, doubt remains over whether dry nitrogen (N) deposition still contributes a minor proportion of plant N nutrition compared with wet N deposition in urban road environments. This study investigated the δ15N values of road dustfall, soil, moss, camphor leaf and camphor bark samples collected along a distance gradient from the road, suggesting that samples collected near the road have significantly more positive δ15N values than those of remote sites. According to the SIAR model (Stable Isotope Analysis in R) applied to dustfall and moss samples from the roadside, it was found that NH3 from traffic exhaust (8.8 ± 7.1%) contributed much less than traffic-derived NO2 (52.2 ± 10.0%) and soil N (39.0 ± 13.8%) to dustfall bulk N; additionally, 68.6% and 31.4% of N in mosses near the roadside could be explained by dry N deposition (only 20.4 ± 12.5% for traffic-derived NH3) and wet N deposition, respectively. A two-member mixing model was used to analyse the δ15N in continuously collected mature camphor leaf and camphor bark samples, which revealed a similarity of the δ15N values of plant-available deposited N to 15N-enriched traffic-derived NOx-N. We concluded that a relatively high proportion of N inputs in urban road environments was contributed by traffic-related dustfall and NOx rather than NH3. These information provide useful insights into reducing the impacts of traffic exhaust on adjacent ecosystems and can assist policy makers in determining the reconstruction of a monitoring network for N deposition that reaches the road level.
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Affiliation(s)
- Yu Xu
- Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education, School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Huayun Xiao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, No. 99, Linchengxi Road, Guiyang 550081, China.
| | - Daishe Wu
- Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education, School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, China.
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23
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Elliott EM, Yu Z, Cole AS, Coughlin JG. Isotopic advances in understanding reactive nitrogen deposition and atmospheric processing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:393-403. [PMID: 30690373 PMCID: PMC7092373 DOI: 10.1016/j.scitotenv.2018.12.177] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 12/09/2018] [Accepted: 12/11/2018] [Indexed: 05/04/2023]
Abstract
Recent advances in stable isotope measurements now allow for detailed investigations of the sources, transformations, and deposition of reactive nitrogen (N) species. Stable isotopes show promise as a complementary tool for apportioning emissions sources that contribute to deposition and also for developing a more robust understanding of the transformations that can influence these isotope ratios. Methodological advances have facilitated the unprecedented examination of the isotopic composition of reactive N species in the atmosphere and in precipitation including nitrogen oxides (NOx = nitric oxide (NO) + nitrogen dioxide (NO2)), atmospheric nitrate (NO3-), nitric acid (HNO3), ammonia (NH3), and ammonium (NH4+). This isotopic information provides new insight into the mechanisms of transformation and cycling of reactive N in the atmosphere and moreover helps resolve the contribution of multiple NOx and NH3 emission sources to deposition across landscapes, regions, and continents. Here, we highlight the current state of knowledge regarding the isotopic ratios of NOx and NH3 emission sources and chemical alterations of isotopic ratios during atmospheric transformations. We also highlight illustrative examples where isotopic approaches are used and review recent methodological advances. While these highlights are not an exhaustive review of the literature, we hope they provide a glimpse of the potential for these methods to help resolve knowledge gaps regarding total N deposition to Earth surfaces. We conclude with promising opportunities for future research in the short-, medium-, and long-term.
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Affiliation(s)
- Emily M Elliott
- Department of Geology & Environmental Science, University of Pittsburgh, United States of America.
| | - Zhongjie Yu
- Department of Geology & Environmental Science, University of Pittsburgh, United States of America
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24
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Luo L, Wu Y, Xiao H, Zhang R, Lin H, Zhang X, Kao SJ. Origins of aerosol nitrate in Beijing during late winter through spring. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 653:776-782. [PMID: 30759603 DOI: 10.1016/j.scitotenv.2018.10.306] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/16/2018] [Accepted: 10/22/2018] [Indexed: 06/09/2023]
Abstract
Recent studies have identified aerosol nitrate (NO3-) as one of the most important inorganic ions; however, quantitative studies of aerosol NO3- sources are rarely undertaken. Total suspended particulate samples were collected in Beijing from 1 February to 31 May 2013, and water-soluble ions and δ15N-NO3- were analysed to examine the potential sources of aerosol NO3-. Using a Bayesian model, the fractional contributions of NOx from different sources to aerosol NO3- were quantified herein. The maximal concentrations of NO3-, Cl-, and K+, as well as values of δ15N-NO3- during the heating period (from 1 February to 15 March) implied that coal combustion was the dominant source of aerosol NO3-. Concentrations of NO3- and K+ in the transition period (from 16 March to 15 April, when heating is gradually reduced in northern China) were similar to those during the non-heating period (from 16 April to 31 May). However, δ15N-NO3- and Cl- were obviously higher in the transition period than those in the non-heating period, suggesting a shift in NO3- sources from the transition period to the non-heating period. The fractional contribution of NO3- from coal combustion was 70.6 ± 5.0% during the heating period, which confirms that coal combustion is the dominant source of NO3- in late winter to early spring 2013 in Beijing. The fractional contribution of biomass burning to aerosol NO3- obviously increased from the heating period to the non-heating period, indicating that biomass burning was an important source of NOx in late spring 2013 in Beijing. This study verified that reduced coal consumption and prohibition of biomass burning can lower aerosol NO3- concentrations in northern China.
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Affiliation(s)
- Li Luo
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang 330013, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China.
| | - Yunfei Wu
- Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Huayun Xiao
- Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang 330013, China.
| | - Renjian Zhang
- Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Hua Lin
- Key Laboratory of Marine Ecosystem and Biogeochemistry, The Second Institute of Oceanography, SOA, Hangzhou 310012, China
| | - Xiaoling Zhang
- School of Atmospheric Sciences/Plateau Atmosphere and Environment Key Laboratory of Sichuan Province, Chengdu University of Information Technology, Chengdu 610225, China
| | - Shuh-Ji Kao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China
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25
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Park YM, Park KS, Kim H, Yu SM, Noh S, Kim MS, Kim JY, Ahn JY, Lee MD, Seok KS, Kim YH. Characterizing isotopic compositions of TC-C, NO3 --N, and NH 4+-N in PM 2.5 in South Korea: Impact of China's winter heating. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 233:735-744. [PMID: 29126095 DOI: 10.1016/j.envpol.2017.10.072] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 09/14/2017] [Accepted: 10/18/2017] [Indexed: 06/07/2023]
Abstract
The origin of PM2.5 has long been the subject of debate and stable isotopic tools have been applied to decipher. In this study, weekly PM2.5 samples were simultaneously collected at an urban (Seoul) and rural (Baengnyeong Island) site in Korea from January 2014 through February 2016. The seasonal variation of isotopic species showed significant seasonal differences with sinusoidal variation. The isotopic results implied that isotope species from Baengnyeong were mostly originated from coal combustion during China's winter heating seasons, whereas in summer, the isotopic patterns observed that were more likely to be from marine. In Seoul, coal combustion related isotopic patterns increased during China's winter heating period while vehicle related isotopic patterns were dominated whole seasons by default. Therefore, aerosol formation was originated from long-range transported coal combustion-related NOx by vehicle-related NH3 in Seoul. δN-NH4+ in Seoul showed highly enriched 15N compositions in all seasons, indicating that NH3 from vehicle emission is the important source of NH4+ in PM2.5 in Seoul. In addition, Baengnyeong should be consistently considered as a key region for observing the changes of isotopic features depend on the contribution of individual emissions to the atmospheric as a result of the reduction of coal consumption in China.
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Affiliation(s)
- Yu-Mi Park
- Chemicals Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Kwang-Su Park
- Chemicals Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Hyuk Kim
- Chemicals Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Seok-Min Yu
- Chemicals Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Seam Noh
- Chemicals Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Min-Seob Kim
- Environmental Measurement and Analysis Center, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Jee-Young Kim
- Environmental Measurement and Analysis Center, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Joon-Young Ahn
- Atmospheric Environmental Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Min-do Lee
- Atmospheric Environmental Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Kwang-Seol Seok
- Chemicals Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea
| | - Young-Hee Kim
- Chemicals Research Division, National Institute of Environmental Research (NIER), Incheon 22689, Republic of Korea.
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26
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Liu XY, Xiao HW, Xiao HY, Song W, Sun XC, Zheng XD, Liu CQ, Koba K. Stable isotope analyses of precipitation nitrogen sources in Guiyang, southwestern China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 230:486-494. [PMID: 28688925 DOI: 10.1016/j.envpol.2017.06.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 04/05/2017] [Accepted: 06/03/2017] [Indexed: 06/07/2023]
Abstract
To constrain sources of anthropogenic nitrogen (N) deposition is critical for effective reduction of reactive N emissions and better evaluation of N deposition effects. This study measured δ15N signatures of nitrate (NO3-), ammonium (NH4+) and total dissolved N (TDN) in precipitation at Guiyang, southwestern China and estimated contributions of dominant N sources using a Bayesian isotope mixing model. For NO3-, the contribution of non-fossil N oxides (NOx, mainly from biomass burning (24 ± 12%) and microbial N cycle (26 ± 5%)) equals that of fossil NOx, to which vehicle exhausts (31 ± 19%) contributed more than coal combustion (19 ± 9%). For NH4+, ammonia (NH3) from volatilization sources (mainly animal wastes (22 ± 12%) and fertilizers (22 ± 10%)) contributed less than NH3 from combustion sources (mainly biomass burning (17 ± 8%), vehicle exhausts (19 ± 11%) and coal combustions (19 ± 12%)). Dissolved organic N (DON) accounted for 41% in precipitation TDN deposition during the study period. Precipitation DON had higher δ15N values in cooler months (13.1‰) than in warmer months (-7.0‰), indicating the dominance of primary and secondary ON sources, respectively. These results newly underscored the importance of non-fossil NOx, fossil NH3 and organic N in precipitation N inputs of urban environments.
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Affiliation(s)
- Xue-Yan Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China.
| | - Hong-Wei Xiao
- Laboratory of Atmospheric Environment, Key Laboratory of Nuclear Resources and Environment (Ministry of Education), East China University of Technology, Nanchang 330013, China; School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang 330013, China
| | - Hua-Yun Xiao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China.
| | - Wei Song
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Xin-Chao Sun
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Xu-Dong Zheng
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Cong-Qiang Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China
| | - Keisuke Koba
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan; Center for Ecological Research, Kyoto University, Shiga, 520-2113, Japan
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27
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Coughlin JG, Yu Z, Elliott EM. Efficacy of passive sampler collection for atmospheric NO 2 isotopes under simulated environmental conditions. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1211-1220. [PMID: 28429398 DOI: 10.1002/rcm.7885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 03/17/2017] [Accepted: 04/14/2017] [Indexed: 05/20/2023]
Abstract
RATIONALE Nitrogen oxides or NOx (NOx = NO + NO2 ) play an important role in air quality, atmospheric chemistry, and climate. The isotopic compositions of anthropogenic and natural NO2 sources are wide-ranging, and they can be used to constrain sources of ambient NO2 and associated atmospheric deposition of nitrogen compounds. While passive sample collection of NO2 isotopes has been used in field studies to determine NOx source influences on atmospheric deposition, this approach has not been evaluated for accuracy or precision under different environmental conditions. METHODS The efficacy of NO2 passive sampler collection for NO2 isotopes was evaluated under varied temperature and relative humidity (RH) conditions in a dynamic flux chamber. The precision and accuracy of the filter NO2 collection as nitrite (NO2- ) for isotopic analysis were determined using a reference NO2 gas tank and through inter-calibration with a modified EPA Method 7. The bacterial denitrifer method was used to convert 20 μM of collected NO2- or nitrate (NO3- ) into N2 O and was carried out on an Isoprime continuous flow isotope ratio mass spectrometer. RESULTS δ15 N-NO2 values determined from passive NO2 collection, in conditions of 11-34 °C, 1-78% RH, have an overall accuracy and precision of ±2.1 ‰, and individual run precision of ±0.6 ‰. δ18 O-NO2 values obtained from passive NO2 sampler collection, under the same conditions, have an overall precision of ± 1.3 ‰. CONCLUSIONS Suitable conditions for passive sampler collection of NO2 isotopes are in environments ranging from 11 to 34 °C and 1 to 78% RH. The passive NO2 isotope measurement technique provides an accurate method to determine variations in atmospheric δ15 N-NO2 values and a precise method for determining atmospheric δ18 O-NO2 values. The ability to measure NO2 isotopes over spatial gradients at the same temporal resolution provides a unique perspective on the extent and seasonality of fluctuations in atmospheric NO2 isotopic compositions. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Justin G Coughlin
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Zhongjie Yu
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Emily M Elliott
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, 15260, USA
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Venkiteswaran J, Schiff S, Paterson M, Flinn N, Shao H, Elgood R. Changing nitrogen deposition with low δ15N−NH4 + and δ15N−NO3 − values at the Experimental Lakes Area, northwestern Ontario, Canada. Facets (Ott) 2017. [DOI: 10.1139/facets-2016-0060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ammonium deposition at the International Institute for Sustainable Development Experimental Lakes Area (IISD–ELA), in northwestern Ontario, Canada, has doubled in the last 45 years and thus is no longer among the low nitrogen (N) deposition sites in North America. This may be related to the concurrent intensification of Manitoba agriculture to the west and upwind of the ELA. Large increases in ammonium deposition at the ELA were important in driving the observed trend and increased the NH4 + to NO3 − ratio of input to aquatic and terrestrial systems. Stable isotope analyses of two years of bulk (wet and dry) atmospheric deposition revealed very large ranges in δ15N−NH4 + (22‰ range), δ15N−NO3 − (18‰), and δ18O–NO3 − (19‰). Few other δ15N−NH4 +, δ15N−NO3 −, and δ18O–NO3 − values have been published for Canadian precipitation. Increases in δ15N of NH4 + and NO3 − in July occurred with increases in total N deposition. The wide range and seasonal trends of δ15N and δ18O values in ELA precipitation mean that studies characterizing N inputs to watersheds and lakes require an ongoing and comprehensive annual sampling regime. Global trends of declining δ15N of N deposition evident in lake sediment records may be a result of increases in NH4 + deposition with lower δ15N−NH4 + values. Similarly, the relationship in Lake Superior between increasing NO3 − and lower δ15N−NO3 − values may be explained by increased atmospheric deposition of N with low δ15N values.
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Affiliation(s)
- J.J. Venkiteswaran
- Department of Geography and Environmental Studies, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON N2L 3C5, Canada
| | - S.L. Schiff
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 6P4, Canada
| | - M.J. Paterson
- IISD–Experimental Lakes Area, 111 Lombard Avenue, Suite 325, Winnipeg, MB R3B 0T4, Canada
| | - N.A.P. Flinn
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 6P4, Canada
| | - H. Shao
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 6P4, Canada
| | - R.J. Elgood
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 6P4, Canada
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Walters WW, Michalski G. Ab initio study of nitrogen and position-specific oxygen kinetic isotope effects in the NO + O 3 reaction. J Chem Phys 2016; 145:224311. [PMID: 27984902 DOI: 10.1063/1.4968562] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ab initio calculations have been carried out to investigate nitrogen (k15/k14) and position-specific oxygen (k17/k16O & k18/k16) kinetic isotope effects (KIEs) for the reaction between NO and O3 using CCSD(T)/6-31G(d) and CCSD(T)/6-311G(d) derived frequencies in the complete Bigeleisen equations. Isotopic enrichment factors are calculated to be -6.7‰, -1.3‰, -44.7‰, -14.1‰, and -0.3‰ at 298 K for the reactions involving the 15N16O, 14N18O, 18O16O16O, 16O18O16O, and 16O16O18O isotopologues relative to the 14N16O and 16O3 isotopologues, respectively (CCSD(T)/6-311G(d)). Using our oxygen position-specific KIEs, a kinetic model was constructed using Kintecus, which estimates the overall isotopic enrichment factors associated with unreacted O3 and the oxygen transferred to NO2 to be -19.6‰ and -22.8‰, respectively, (CCSD(T)/6-311G(d)) which tends to be in agreement with previously reported experimental data. While this result may be fortuitous, this agreement suggests that our model is capturing the most important features of the underlying physics of the KIE associated with this reaction (i.e., shifts in zero-point energies). The calculated KIEs will useful in future NOx isotopic modeling studies aimed at understanding the processes responsible for the observed tropospheric isotopic variations of NOx as well as for tropospheric nitrate.
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Affiliation(s)
- Wendell W Walters
- Department of Earth, Atmospheric, and Planetary Sciences Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, USA
| | - Greg Michalski
- Department of Earth, Atmospheric, and Planetary Sciences Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, USA
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Walters WW, Tharp BD, Fang H, Kozak BJ, Michalski G. Nitrogen Isotope Composition of Thermally Produced NOx from Various Fossil-Fuel Combustion Sources. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:11363-71. [PMID: 26332865 DOI: 10.1021/acs.est.5b02769] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The nitrogen stable isotope composition of NOx (δ(15)N-NOx) may be a useful indicator for NOx source partitioning, which would help constrain NOx source contributions in nitrogen deposition studies. However, there is large uncertainty in the δ(15)N-NOx values for anthropogenic sources other than on-road vehicles and coal-fired energy generating units. To this end, this study presents a broad analysis of δ(15)N-NOx from several fossil-fuel combustion sources that includes: airplanes, gasoline-powered vehicles not equipped with a three-way catalytic converter, lawn equipment, utility vehicles, urban buses, semitrucks, residential gas furnaces, and natural-gas-fired power plants. A relatively large range of δ(15)N-NOx values was measured from -28.1‰ to 8.5‰ for individual exhaust/flue samples that generally tended to be negative due to the kinetic isotope effect associated with thermal NOx production. A negative correlation between NOx concentrations and δ(15)N-NOx for fossil-fuel combustion sources equipped with selective catalytic reducers was observed, suggesting that the catalytic reduction of NOx increases δ(15)N-NOx values relative to the NOx produced through fossil-fuel combustion processes. Combining the δ(15)N-NOx measured in this study with previous published values, a δ(15)N-NOx regional and seasonal isoscape was constructed for the contiguous U.S., which demonstrates seasonal and regional importance of various NOx sources.
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Affiliation(s)
- Wendell W Walters
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University , 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Bruce D Tharp
- Department of Chemistry, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Huan Fang
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University , 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Brian J Kozak
- Department of Aviation Technology, Purdue University , 1401 Aviation Drive, West Lafayette, Indiana 47907, United States
| | - Greg Michalski
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University , 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
- Department of Chemistry, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States
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Mueller C, Krieg R, Merz R, Knöller K. Regional nitrogen dynamics in the TERENO Bode River catchment, Germany, as constrained by stable isotope patterns. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2015; 52:61-74. [PMID: 25811939 DOI: 10.1080/10256016.2015.1019489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Interactions between hydrological characteristics and microbial activities affect the isotopic composition of dissolved nitrate in surface water. Nitrogen and oxygen isotopic signatures of riverine nitrate in 133 sampling locations distributed over the Bode River catchment in the Harz Mountains, Germany, were used to identify nitrate sources and transformation processes. An annual monitoring programme consisting of seasonal sampling campaigns in spring, summer and autumn was conducted. δ(15)N and δ(18)O of nitrate and corresponding concentrations were measured as well as δ(2)H and δ(18)O of water to determine the deuterium excess. In addition, precipitation on 25 sampling stations was sampled and considered as a potential input factor. The Bode River catchment is strongly influenced by agricultural land use which is about 70 % of the overall size of the catchment. Different nitrogen sources such as ammonia (NH4) fertilizer, soil nitrogen, organic fertilizer or nitrate in precipitation show partly clear nitrate isotopic differences. Processes such as microbial denitrification result in fractionation and lead to an increase in δ(15)N of nitrate. We observed an evident regional and partly temporal variation of nitrate isotope signatures which are clearly different between main landscape types. Spring water sections within the high mountains contain nitrate in low concentrations with low δ(15)NNO3 values of -3 ‰ and high δ(18)ONO3 values up to 13 ‰. High mountain stream water sub-catchments dominated by nearly undisturbed forest and grassland contribute nitrate with δ(15)NNO3 and δ(18)ONO3 values of -1 and -3.5 ‰, respectively. In the further flow path, which is affected by an increasing agricultural land use and urban sewage, we recognized an increase in δ(15)NNO3 and δ(18)ONO3 up to 22 and 18 ‰, respectively, with high variations during the year. A correlation seems to exist between the percentage of agricultural land use area and the corresponding δ(15)NNO3 values for sub-catchments. A shift towards heavier isotope values in stream water samples taken in July 2012 is significant (p-value = 6 · 10(-6)) compared to samples from March and October 2012. We also see a season-depending impact of microbial denitrification. Denitrification, especially evident in the lowlands, predominantly takes place in the riverbeds. In addition, mixing processes of different nitrate sources and temperature-depending biological processes such as nitrification have to be taken into consideration. Constant-tempered groundwater does not play a noticeable role in the processes of the stream water system. As constrained from oxygen isotope signatures, precipitation associated with low nitrate concentrations does not have an obvious impact on stream water nitrate in the high mountain region.
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Affiliation(s)
- Christin Mueller
- a Department of Catchment Hydrology , Helmholtz Centre for Environmental Research - UFZ , Halle (Saale) , Germany
| | - Ronald Krieg
- a Department of Catchment Hydrology , Helmholtz Centre for Environmental Research - UFZ , Halle (Saale) , Germany
| | - Ralf Merz
- a Department of Catchment Hydrology , Helmholtz Centre for Environmental Research - UFZ , Halle (Saale) , Germany
| | - Kay Knöller
- a Department of Catchment Hydrology , Helmholtz Centre for Environmental Research - UFZ , Halle (Saale) , Germany
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Walters WW, Goodwin SR, Michalski G. Nitrogen stable isotope composition (δ15N) of vehicle-emitted NOx. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2278-85. [PMID: 25621737 DOI: 10.1021/es505580v] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The nitrogen stable isotope ratio of NOx (δ(15)N-NOx) has been proposed as a regional indicator for NOx source partitioning; however, knowledge of δ(15)N values from various NOx emission sources is limited. This study presents a detailed analysis of δ(15)N-NOx emitted from vehicle exhaust, the largest source of anthropogenic NOx. To accomplish this, NOx was collected from 26 different vehicles, including gasoline and diesel-powered engines, using a modification of a NOx collection method used by the United States Environmental Protection Agency, and δ(15)N-NOx was analyzed. The vehicles sampled in this study emitted δ(15)N-NOx values ranging from -19.1 to 9.8‰ that negatively correlated with the emitted NOx concentrations (8.5 to 286 ppm) and vehicle run time because of kinetic isotope fractionation effects associated with the catalytic reduction of NOx. A model for determining the mass-weighted δ(15)N-NOx from vehicle exhaust was constructed on the basis of average commute times, and the model estimates an average value of -2.5 ± 1.5‰, with slight regional variations. As technology improvements in catalytic converters reduce cold-start emissions in the future, it is likely to increase current δ(15)N-NOx values emitted from vehicles.
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Affiliation(s)
- Wendell W Walters
- Department of Earth, Atmospheric, and Planetary Sciences and ‡Department of Chemistry, Purdue University , 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
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Fibiger DL, Hastings MG, Lew AF, Peltier RE. Collection of NO and NO2 for isotopic analysis of NO(x) emissions. Anal Chem 2014; 86:12115-21. [PMID: 25415365 DOI: 10.1021/ac502968e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There have been several measurements made of the nitrogen isotopic composition of gaseous NOx (NOx = NO + NO2) from various emission sources, utilizing a wide variety of methods to collect the NOx in solution as nitrate or nitrite. However, previous collection techniques have not been verified for complete or efficient capture of NOx such that the isotopic composition of NOx remains unaltered during collection. Here, we present a method of collecting NOx (NO + NO2) in solution as nitrate to evaluate the nitrogen isotopic composition of the NOx (δ(15)N-NOx). Using a 0.25 M KMnO4 and 0.5 M NaOH solution, quantitative NOx collection was achieved under a variety of conditions in laboratory and field settings, allowing for isotopic analysis without correcting for fractionations. The uncertainty across the entire analytic procedure is ±1.5‰ (1σ). With this method, a more robust inventory of NOx source isotopic composition is possible, which has implications for studies of air quality and acid deposition.
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Affiliation(s)
- Dorothy L Fibiger
- Brown University , Department of Chemistry, 324 Brook Street, Providence, Rhode Island 02912, United States
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Beyn F, Matthias V, Dähnke K. Changes in atmospheric nitrate deposition in Germany--an isotopic perspective. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 194:1-10. [PMID: 25078659 DOI: 10.1016/j.envpol.2014.06.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/10/2014] [Accepted: 06/26/2014] [Indexed: 06/03/2023]
Abstract
We investigated the isotopic composition of atmospheric NO3(-) deposition at a moderately polluted site in Western Europe over an annual cycle from December 2011 to November 2012. On average, we measured load-weighted δ(15)N values of +0.1 and +3.0‰ in wet and dry deposition, respectively. A comparison to source-specific N emission trends and to isotope data from the 1980s reveals distinct changes in δ(15)N-NO3(-) values: In contrast to the increasing relative importance of isotopically depleted natural NOx sources, we find an increase of isotope values in comparison to historical data. We explore the role of land-based N sources, because backward trajectories reveal a correlation of higher δ(15)N to air mass origin from industrialized areas. Nowadays isotopically enriched NOx of coal-fired power plants using selective catalytic converters and land-based vehicle emissions, which use same technology, are apparently the main driver of rising δ(15)N values in nitrate deposition.
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Affiliation(s)
- Fabian Beyn
- Helmholtz Centre Geesthacht, Institute for Coastal Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
| | - Volker Matthias
- Helmholtz Centre Geesthacht, Institute for Coastal Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany
| | - Kirstin Dähnke
- Helmholtz Centre Geesthacht, Institute for Coastal Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany
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Nitrogen isotopes in ice core nitrate linked to anthropogenic atmospheric acidity change. Proc Natl Acad Sci U S A 2014; 111:5808-12. [PMID: 24711383 DOI: 10.1073/pnas.1319441111] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nitrogen stable isotope ratio (δ(15)N) in Greenland snow nitrate and in North American remote lake sediments has decreased gradually beginning as early as ∼1850 Christian Era. This decrease was attributed to increasing atmospheric deposition of anthropogenic nitrate, reflecting an anthropogenic impact on the global nitrogen cycle, and the impact was thought to be amplified ∼1970. However, our subannually resolved ice core records of δ(15)N and major ions (e.g., NO3(-), SO4(2-)) over the last ∼200 y show that the decrease in δ(15)N is not always associated with increasing NO3(-) concentrations, and the decreasing trend actually leveled off ∼1970. Correlation of δ(15)N with H(+), NO3(-), and HNO3 concentrations, combined with nitrogen isotope fractionation models, suggests that the δ(15)N decrease from ∼1850-1970 was mainly caused by an anthropogenic-driven increase in atmospheric acidity through alteration of the gas-particle partitioning of atmospheric nitrate. The concentrations of NO3(-) and SO4(2-) also leveled off ∼1970, reflecting the effect of air pollution mitigation strategies in North America on anthropogenic NO(x) and SO2 emissions. The consequent atmospheric acidity change, as reflected in the ice core record of H(+) concentrations, is likely responsible for the leveling off of δ(15)N ∼1970, which, together with the leveling off of NO3(-) concentrations, suggests a regional mitigation of anthropogenic impact on the nitrogen cycle. Our results highlight the importance of atmospheric processes in controlling δ(15)N of nitrate and should be considered when using δ(15)N as a source indicator to study atmospheric flux of nitrate to land surface/ecosystems.
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Isotopic composition of atmospheric nitrate in a tropical marine boundary layer. Proc Natl Acad Sci U S A 2013; 110:17668-73. [PMID: 23431201 DOI: 10.1073/pnas.1216639110] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Long-term observations of the reactive chemical composition of the tropical marine boundary layer (MBL) are rare, despite its crucial role for the chemical stability of the atmosphere. Recent observations of reactive bromine species in the tropical MBL showed unexpectedly high levels that could potentially have an impact on the ozone budget. Uncertainties in the ozone budget are amplified by our poor understanding of the fate of NOx (= NO + NO2), particularly the importance of nighttime chemical NOx sinks. Here, we present year-round observations of the multiisotopic composition of atmospheric nitrate in the tropical MBL at the Cape Verde Atmospheric Observatory. We show that the observed oxygen isotope ratios of nitrate are compatible with nitrate formation chemistry, which includes the BrNO3 sink at a level of ca. 20 ± 10% of nitrate formation pathways. The results also suggest that the N2O5 pathway is a negligible NOx sink in this environment. Observations further indicate a possible link between the NO2/NOx ratio and the nitrogen isotopic content of nitrate in this low NOx environment, possibly reflecting the seasonal change in the photochemical equilibrium among NOx species. This study demonstrates the relevance of using the stable isotopes of oxygen and nitrogen of atmospheric nitrate in association with concentration measurements to identify and constrain chemical processes occurring in the MBL.
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Morin S, Erbland J, Savarino J, Domine F, Bock J, Friess U, Jacobi HW, Sihler H, Martins JMF. An isotopic view on the connection between photolytic emissions of NOxfrom the Arctic snowpack and its oxidation by reactive halogens. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016618] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kundu S, Kawamura K, Lee M. Seasonal variation of the concentrations of nitrogenous species and their nitrogen isotopic ratios in aerosols at Gosan, Jeju Island: Implications for atmospheric processing and source changes of aerosols. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd013323] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Elliott EM, Kendall C, Boyer EW, Burns DA, Lear GG, Golden HE, Harlin K, Bytnerowicz A, Butler TJ, Glatz R. Dual nitrate isotopes in dry deposition: Utility for partitioning NOxsource contributions to landscape nitrogen deposition. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jg000889] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jarvis JC, Hastings MG, Steig EJ, Kunasek SA. Isotopic ratios in gas-phase HNO3and snow nitrate at Summit, Greenland. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jd012134] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Morin S, Savarino J, Frey MM, Domine F, Jacobi HW, Kaleschke L, Martins JMF. Comprehensive isotopic composition of atmospheric nitrate in the Atlantic Ocean boundary layer from 65°S to 79°N. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd010696] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Morin S, Savarino J, Frey MM, Yan N, Bekki S, Bottenheim JW, Martins JMF. Tracing the Origin and Fate of NO
x
in the Arctic Atmosphere Using Stable Isotopes in Nitrate. Science 2008; 322:730-2. [DOI: 10.1126/science.1161910] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Samuel Morin
- CNRS, Institut National des Sciences de l'Univers, France
- Laboratoire de Glaciologie et de Géophysique de l'Environnement, Université Joseph Fourier (UJF), Grenoble, France
- Service d'Aeronomie, Institut Pierre-Simon Laplace, Université Pierre et Marie Curie, Paris 6, Paris, France
- Environment Canada, Toronto, Ontario, Canada
- Laboratoire d'Etude des Transferts en Hydrologie et Environnement, UJF, Grenoble, France
| | - Joël Savarino
- CNRS, Institut National des Sciences de l'Univers, France
- Laboratoire de Glaciologie et de Géophysique de l'Environnement, Université Joseph Fourier (UJF), Grenoble, France
- Service d'Aeronomie, Institut Pierre-Simon Laplace, Université Pierre et Marie Curie, Paris 6, Paris, France
- Environment Canada, Toronto, Ontario, Canada
- Laboratoire d'Etude des Transferts en Hydrologie et Environnement, UJF, Grenoble, France
| | - Markus M. Frey
- CNRS, Institut National des Sciences de l'Univers, France
- Laboratoire de Glaciologie et de Géophysique de l'Environnement, Université Joseph Fourier (UJF), Grenoble, France
- Service d'Aeronomie, Institut Pierre-Simon Laplace, Université Pierre et Marie Curie, Paris 6, Paris, France
- Environment Canada, Toronto, Ontario, Canada
- Laboratoire d'Etude des Transferts en Hydrologie et Environnement, UJF, Grenoble, France
| | - Nicolas Yan
- CNRS, Institut National des Sciences de l'Univers, France
- Laboratoire de Glaciologie et de Géophysique de l'Environnement, Université Joseph Fourier (UJF), Grenoble, France
- Service d'Aeronomie, Institut Pierre-Simon Laplace, Université Pierre et Marie Curie, Paris 6, Paris, France
- Environment Canada, Toronto, Ontario, Canada
- Laboratoire d'Etude des Transferts en Hydrologie et Environnement, UJF, Grenoble, France
| | - Slimane Bekki
- CNRS, Institut National des Sciences de l'Univers, France
- Laboratoire de Glaciologie et de Géophysique de l'Environnement, Université Joseph Fourier (UJF), Grenoble, France
- Service d'Aeronomie, Institut Pierre-Simon Laplace, Université Pierre et Marie Curie, Paris 6, Paris, France
- Environment Canada, Toronto, Ontario, Canada
- Laboratoire d'Etude des Transferts en Hydrologie et Environnement, UJF, Grenoble, France
| | - Jan W. Bottenheim
- CNRS, Institut National des Sciences de l'Univers, France
- Laboratoire de Glaciologie et de Géophysique de l'Environnement, Université Joseph Fourier (UJF), Grenoble, France
- Service d'Aeronomie, Institut Pierre-Simon Laplace, Université Pierre et Marie Curie, Paris 6, Paris, France
- Environment Canada, Toronto, Ontario, Canada
- Laboratoire d'Etude des Transferts en Hydrologie et Environnement, UJF, Grenoble, France
| | - Jean M. F. Martins
- CNRS, Institut National des Sciences de l'Univers, France
- Laboratoire de Glaciologie et de Géophysique de l'Environnement, Université Joseph Fourier (UJF), Grenoble, France
- Service d'Aeronomie, Institut Pierre-Simon Laplace, Université Pierre et Marie Curie, Paris 6, Paris, France
- Environment Canada, Toronto, Ontario, Canada
- Laboratoire d'Etude des Transferts en Hydrologie et Environnement, UJF, Grenoble, France
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Savarino J, Bhattacharya SK, Morin S, Baroni M, Doussin JF. The NO+O3 reaction: A triple oxygen isotope perspective on the reaction dynamics and atmospheric implications for the transfer of the ozone isotope anomaly. J Chem Phys 2008; 128:194303. [DOI: 10.1063/1.2917581] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Elliott EM, Kendall C, Wankel SD, Burns DA, Boyer EW, Harlin K, Bain DJ, Butler TJ. Nitrogen isotopes as indicators of NO(x) source contributions to atmospheric nitrate deposition across the midwestern and northeastern United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:7661-7. [PMID: 18075071 DOI: 10.1021/es070898t] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Global inputs of NO(x) are dominated by fossil fuel combustion from both stationary and vehicular sources and far exceed natural NO(x) sources. However, elucidating NO(x) sources to any given location remains a difficult challenge, despite the need for this information to develop sound regulatory and mitigation strategies. We present results from a regional-scale study of nitrogen isotopes (delta15N) in wet nitrate deposition across 33 sites in the midwestern and northeastern U.S. We demonstrate that spatial variations in delta15N are strongly correlated with NO(x) emissions from surrounding stationary sources and additionally that delta15N is more strongly correlated with surrounding stationary source NO(x) emissions than pH, SO4(2-), or NO3- concentrations. Although emission inventories indicate that vehicle emissions are the dominant NO(x) source in the eastern U.S., our results suggest that wet NO3- deposition at sites in this study is strongly associated with NO(x) emissions from stationary sources. This suggests that large areas of the landscape potentially receive atmospheric NO(y) deposition inputs in excess of what one would infer from existing monitoring data alone. Moreover, we determined that spatial patterns in delta15N values are a robust indicator of stationary NO(x) contributions to wet NO3- deposition and hence a valuable complement to existing tools for assessing relationships between NO3- deposition, regional emission inventories, and for evaluating progress toward NO(x) reduction goals.
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Affiliation(s)
- E M Elliott
- U.S. Geological Survey, Water Resources Division, 345 Middlefield Road, Menlo Park, California 94025, USA.
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Hastings MG. Seasonal variations in N and O isotopes of nitrate in snow at Summit, Greenland: Implications for the study of nitrate in snow and ice cores. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jd004991] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hastings MG, Sigman DM, Lipschultz F. Isotopic evidence for source changes of nitrate in rain at Bermuda. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2003jd003789] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Daniel M. Sigman
- Department of Geosciences; Princeton University; Princeton New Jersey USA
| | - Fred Lipschultz
- Bermuda Biological Station for Research; St George's Bermuda
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Jung K, Gebauer G, Gehre M, Hofmann D, Weissflog L, Schüürmann G. Anthropogenic impacts on natural nitrogen isotope variations in Pinus sylvestris stands in an industrially polluted area. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 1997; 97:175-181. [PMID: 15093392 DOI: 10.1016/s0269-7491(97)00053-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/1996] [Accepted: 03/27/1997] [Indexed: 05/24/2023]
Abstract
Natural variations of the nitrogen isotopes 15N/14N (delta15N values) and the N concentrations of one-year-old needles from 7-12-year-old pine trees (Pinus sylvestris L.) were determined on 27 sites in the heavily polluted Leipzig-Halle region (former GDR). At three selected sites measurements were repeated over a period of 2 years. N concentrations and delta15N values in different needle age classes were compared at the three sites. The delta15N values of the N in the humus layer and the potential plant available N in the A(h) horizon of the local soil were determined. The 15N/14N isotope ratios (delta15N values) of one-year-old pine needles in the region of Leipzig-Halle were found to vary depending on their specific location by a factor of up to one order of magnitude (-9.6 per thousand to + 0.4 per thousand ). N concentrations in one-year-old pine needles varied between 0.71 and 1.38 mmol eq N g dw(-1). Pine stands with positive or slightly negative delta15N values and high N concentrations in one-year-old needles were concentrated around the cities of Leipzig and Halle and in the industrial areas. More negative delta15N values and lower N concentrations in one-year-old pine needles were found on sites at greater distances from the industrial agglomerations, mainly in the NE forested part. Site specific differences in the delta15N values of the N in the humus layer from three selected sites were similar to those found for the needles. No site specific differences, however, were found for the delta15N values of the water soluble nitrogen fraction from the mineral soil horizons of the same sites.
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Affiliation(s)
- K Jung
- Department of Chemical Ecotoxicology, Centre for Environmental Research Leipzig-Halle, P.O. Box 2, D-04301 Leipzig, Germany
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