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Zheng X, Liu J, Zhong B, Wang Y, Wu Z, Chuduo N, Ba B, Yuan X, Fan M, Cao F, Zhang Y, Chen W, Zhou L, Ma N, Yu P, Li J, Zhang G. Insights into anthropogenic impact on atmospheric inorganic aerosols in the largest city of the Tibetan Plateau through multidimensional isotope analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 929:172643. [PMID: 38649049 DOI: 10.1016/j.scitotenv.2024.172643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/18/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
Particulate inorganic nitrogen aerosols (PIN) significantly influence air pollution and pose health risks worldwide. Despite extensive observations on ammonium (pNH4+) and nitrate (pNO3-) aerosols in various regions, their key sources and mechanisms in the Tibetan Plateau remain poorly understood. To bridge this gap, this study conducted a sampling campaign in Lhasa, the Tibetan Plateau's largest city, with a focus on analyzing the multiple isotopic signatures (δ15N, ∆17O). These isotopes were integrated into a Bayesian mixing model to quantify the source contributions and oxidation pathways for pNH4+ and pNO3-. Our results showed that traffic was the largest contributor to pNH4+ (31.8 %), followed by livestock (25.4 %), waste (21.8 %), and fertilizer (21.0 %), underscoring the impact of vehicular emissions on urban NH3 levels in Lhasa. For pNO3-, coal combustion emerged as the largest contributor (27.3 %), succeeded by biomass burning (26.3 %), traffic emission (25.3 %), and soil emission (21.1 %). In addition, the ∆17O-based model indicated a dominant role of NO2 + OH (52.9 %) in pNO3- production in Lhasa, which was similar to previous observations. However, it should be noted that the NO3 + volatile organic component (VOC) contributed up to 18.5 % to pNO3- production, which was four times higher than the Tibetan Plateau's background regions. Taken together, the multidimensional isotope analysis performed in this study elucidates the pronounced influence of anthropogenic activities on PIN in the atmospheric environment of Lhasa.
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Affiliation(s)
- Xueqin Zheng
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Junwen Liu
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China.
| | - Bingqian Zhong
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Yujing Wang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Department of Environmental Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zeyan Wu
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Nima Chuduo
- Lhasa Meteorological Administration, Lhasa 850010, China
| | - Bian Ba
- Lhasa Meteorological Administration, Lhasa 850010, China
| | - Xin Yuan
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Meiyi Fan
- School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Fang Cao
- School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Yanlin Zhang
- School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Weihua Chen
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Luxi Zhou
- Guangzhou Institute of Tropical and Marine Meteorology, Meteorological Administration, Guangzhou 510640, China
| | - Nan Ma
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Pengfei Yu
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Jun Li
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
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Xiao H, Ji C, Ding S, Li X. Strategic control of combustion-induced ammonia emissions: A key initiative for substantial PM 2.5 reduction in Tianjin, North China Plain. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 928:172328. [PMID: 38614324 DOI: 10.1016/j.scitotenv.2024.172328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/11/2024] [Accepted: 04/06/2024] [Indexed: 04/15/2024]
Abstract
Information on the temporal and spatial variations in the sources of ammonium salts (NH4+), a crucial alkaline component in PM2.5, is limited. Here, we simultaneously collected PM2.5 and gaseous ammonia (NH3) samples in both summer and winter from two sites in Tianjin: an urban site (Tianjin University, TJU) and a suburban site (Binhai New-region, BH). NH3 concentrations, the contents of major water-soluble inorganic ions in PM2.5, and the compositions of ammonium‑nitrogen isotopes (δ15N-NH4+) were measured. As a result, (NH4)2SO4 and NH4NO3 were the predominant forms of NH4+ in PM2.5 during summer and winter, respectively. However, the NH4NO3 concentrations were notably greater at TJU (6.2 ± 7.3 μg m-3) than at BH (3.8 ± 4.7 μg m-3) in summer, with no regional differences observed in winter. Both sites displayed almost half the contribution of c-NH3 (combustion-related NH3) to NH4+, differing from the finding of previous isotope-based studies. This discrepancy could be attributed to the combined effects of NHx isotope fractionation and seasonal δ15N value variations in NH3 sources. The contribution fractions of v-NH3 (volatile NH3) and c-NH3 exhibited similar patterns at both sites seasonally, probably caused by coal combustion for heating in winter and temperature fluctuations. However, the contribution fraction of c-NH3 was lower at BH than at TJU in summer but greater in winter than at TJU. In summer, NH4NO3 was unstable and limited its delivery to TJU from BH, and the high contribution of c-NH3 to NH4+ at TJU could be attributed to local vehicle emissions. In winter, the stable particulate NH4NO3 that formed from the c-NH3 in the upwind area could be transported to the downwind area, increasing the NH4+ concentration at BH. Our study provides valuable insights for devising emission mitigation strategies to alleviate the increasing burden of NH3 in the local atmosphere.
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Affiliation(s)
- Hao Xiao
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Chuanwen Ji
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Shiyuan Ding
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Xiaodong Li
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
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Wang Q, Du W, Zhou W, Zhang Y, Xie C, Zhao J, Xu W, Tang G, Fu P, Wang Z, Sun Y, Peng L. Characteristics of sub-micron aerosols above the urban canopy in Beijing during warm seasons. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171989. [PMID: 38547971 DOI: 10.1016/j.scitotenv.2024.171989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/15/2024] [Accepted: 03/24/2024] [Indexed: 04/06/2024]
Abstract
To understand the characteristics of atmospheric pollution above the urban canopy in warm seasons, the characteristics of sub-micron aerosol (PM1) was studied based on high-altitude observations at the Beijing 325 m meteorological tower. The PM1 at 260 m was 34, 29 and 21 μg m-3 in May 2015, June 2015, and June 2017, respectively, indicating a reduction in PM1 pollution above the urban canopy. Meanwhile, an overall decrease was also observed in the concentrations of all PM1 chemical species (excluding Chl and BC) and organic aerosol (OA) factors. Previous instances of heavy haze in Beijing often coincided with high humidity and stagnant weather conditions. However, the heightened pollution episodes in June 2017 were accompanied by high wind speeds and low relative humidity. Compared to May 2015, the contribution of secondary components to PM1 in June 2017 was more prominent, with the total proportion of SNA (sulfate, nitrate, and ammonium) and more-oxidized oxygenated OA (MO-OOA) to PM1 increased by approximately 10 %. Secondary species of NH4NO3, (NH4)2SO4, and MO-OOA, as well as black carbon, collectively contributed the vast majority of aerosol extinction coefficient (bext), with the four species contributing a total of ≥96 % to bext at 260 m. Hydrocarbon-like OA, cooking OA, and less-oxidized oxygenated OA have undergone significant reductions, so continued emphasis on controlling local sources to reduce these three aerosol species and addressing regional sources to further mitigate overall aerosol species is imperative. In lower pollution situation, the diurnal variation of PM was smoother, and its pollution sources were more regionally uniform, which might be attributed to the reduced diversity and complexity in the physical and chemical processes in air pollution.
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Affiliation(s)
- Qingqing Wang
- Engineering Research Center of Clean and Low-carbon Technology for Intelligent Transportation, Ministry of Education, School of Environment, Beijing Jiaotong University, Beijing 100044, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
| | - Wei Du
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Institute for Atmospheric and Earth System Research / Physics, Faculty of Science, University of Helsinki, Finland
| | - Wei Zhou
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingjie Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
| | - Conghui Xie
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Laboratory of Gas Instrument Testing, Center for Environmental Metrology, National Institute of Metrology, Beijing 100029, China
| | - Jian Zhao
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Institute for Atmospheric and Earth System Research / Physics, Faculty of Science, University of Helsinki, Finland
| | - Weiqi Xu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guiqian Tang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Pingqing Fu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Zifa Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Lin Peng
- Engineering Research Center of Clean and Low-carbon Technology for Intelligent Transportation, Ministry of Education, School of Environment, Beijing Jiaotong University, Beijing 100044, China.
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Wu L, Wang P, Zhang Q, Ren H, Shi Z, Hu W, Chen J, Xie Q, Li L, Yue S, Wei L, Song L, Zhang Y, Wang Z, Chen S, Wei W, Wang X, Zhang Y, Kong S, Ge B, Yang T, Fang Y, Ren L, Deng J, Sun Y, Wang Z, Zhang H, Hu J, Liu CQ, Harrison RM, Ying Q, Fu P. Dominant contribution of combustion-related ammonium during haze pollution in Beijing. Sci Bull (Beijing) 2024; 69:978-987. [PMID: 38242834 DOI: 10.1016/j.scib.2024.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/21/2024]
Abstract
Aerosol ammonium (NH4+), mainly produced from the reactions of ammonia (NH3) with acids in the atmosphere, has significant impacts on air pollution, radiative forcing, and human health. Understanding the source and formation mechanism of NH4+ can provide scientific insights into air quality improvements. However, the sources of NH3 in urban areas are not well understood, and few studies focus on NH3/NH4+ at different heights within the atmospheric boundary layer, which hinders a comprehensive understanding of aerosol NH4+. In this study, we perform both field observation and modeling studies (the Community Multiscale Air Quality, CMAQ) to investigate regional NH3 emission sources and vertically resolved NH4+ formation mechanisms during the winter in Beijing. Both stable nitrogen isotope analyses and CMAQ model suggest that combustion-related NH3 emissions, including fossil fuel sources, NH3 slip, and biomass burning, are important sources of aerosol NH4+ with more than 60% contribution occurring on heavily polluted days. In contrast, volatilization-related NH3 sources (livestock breeding, N-fertilizer application, and human waste) are dominant on clean days. Combustion-related NH3 is mostly local from Beijing, and biomass burning is likely an important NH3 source (∼15%-20%) that was previously overlooked. More effective control strategies such as the two-product (e.g., reducing both SO2 and NH3) control policy should be considered to improve air quality.
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Affiliation(s)
- Libin Wu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Peng Wang
- Department of Atmospheric and Oceanic Sciences, Fudan University, Shanghai 200438, China; IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health, Fudan University, Shanghai 200438, China
| | - Qiang Zhang
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China
| | - Hong Ren
- Air Environmental Modeling and Pollution Controlling Key Laboratory of Sichuan Higher Education Institute, Chengdu University of Information Technology, Chengdu 610225, China
| | - Zongbo Shi
- Division of Environmental Health & Risk Management, School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Wei Hu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Jing Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Qiaorong Xie
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Linjie Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Siyao Yue
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Lianfang Wei
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Linlin Song
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China
| | - Yonggen Zhang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Zihan Wang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Shuang Chen
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Wan Wei
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Xiaoman Wang
- Department of Atmospheric and Oceanic Sciences, Fudan University, Shanghai 200438, China; IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health, Fudan University, Shanghai 200438, China
| | - Yanlin Zhang
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Shaofei Kong
- Department of Atmospheric Sciences, School of Environmental Studies and Department of Environmental Science and Technology, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Baozhu Ge
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Ting Yang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yunting Fang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China
| | - Lujie Ren
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Junjun Deng
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Zifa Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Hongliang Zhang
- IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health, Fudan University, Shanghai 200438, China; Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Jianlin Hu
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Cong-Qiang Liu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Roy M Harrison
- Division of Environmental Health & Risk Management, School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK; Department of Environmental Sciences/Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Qi Ying
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station TX 77843-3136, USA
| | - Pingqing Fu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
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Yan F, Chen W, Wang X, Jia S, Mao J, Cao J, Chang M. Significant Increase in Ammonia Emissions in China: Considering Nonagricultural Sectors Based on Isotopic Source Apportionment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2423-2433. [PMID: 38270134 DOI: 10.1021/acs.est.3c07222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
Isotopic source apportionment results revealed that nonagricultural sectors are significant sources of ammonia (NH3) emissions, particularly in urban areas. Unfortunately, nonagricultural sources have been substantially underrepresented in the current anthropogenic NH3 emission inventories (EIs). Here, we propose a novel approach to develop a gridded EI of nonagricultural NH3 in China for 2016 using a combination of isotopic source apportionment results and the emission ratios of carbon monoxide (CO) and NH3. We estimated that isotope-corrected nonagricultural NH3 emissions were 4370 Gg in China in 2016, accounting for an increase in the total NH3 emissions from 7 to 31%. As a result, compared to the original NH3 EI, the annual emissions of total NH3 increased by 35%. Thus, in comparison to the simulation driven by the original NH3 EI, the WRF-Chem model driven by the isotope-corrected NH3 EI has reduced the model biases in the surface concentrations and dry deposition flux of reduced nitrogen (NHx = gaseous NH3 + particulate NH4+) by 23 and 31%, respectively. This study may have wide-ranging implications for formulating targeted strategies for nonagricultural NH3 emissions controls, making it facilitate the achievement of simultaneously alleviating nitrogen deposition and atmospheric pollution in the future.
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Affiliation(s)
- Fenghua Yan
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, China
- Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Weihua Chen
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, China
- Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Xuemei Wang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, China
- Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Shiguo Jia
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou 510275, China
| | - Jingying Mao
- Scientific Research Academy of Guangxi Environmental Protection, Nanning 530022, China
| | - Jiachen Cao
- School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Ming Chang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, China
- Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
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6
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Bhattarai N, Wang S, Xu Q, Dong Z, Chang X, Jiang Y, Zheng H. Nitrogen isotopes suggest agricultural and non-agricultural sources contribute equally to NH 3 and NH 4+ in urban Beijing during December 2018. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 326:121455. [PMID: 36934964 DOI: 10.1016/j.envpol.2023.121455] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/07/2023] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
Agricultural and non-agricultural sources emission contribute to atmospheric ammonia (NH3) and particulate ammonium (NH4+). However, our understanding on the sources of NH3 and NH4+ in PM2.5 (particles smaller than 2.5 μm) during the winter period in the urban atmosphere is limited. Here, we measured the concentrations and stable nitrogen isotopic composition (δ15N) of NH3 and NH4+ in parallel during December 2018 in urban Beijing to assess the non-agricultural and agricultural sources contributions to NH3 and NH4+ in ambient air based on the Chemical Transport Model (CTM), a Bayesian isotope mixing model (SIMMR), and the δ15N signatures that we developed. Our study found weekly NH4+ and NH3 concentrations were on average 2.5 ± 1.4 μg m-3 and 3.8 ± 1.7 μg m-3, respectively during December 2018. Weekly concentration weighted δ15N(NH4+) values ranged from 4.5‰ to 13.7‰ with an average value of 8.2 ± 3.9‰ during December 2018. After accounting for nitrogen isotopic fractionation from NH3 gas to NH4+ conversion, initial δ15N(NH3) values ranged from -22.5‰ to -12.8‰ with an average value of -17.4 ± 3.5‰. Further, weekly measured δ15N(NH3) values ranged from -22.2‰ to -10.2‰ (after correction) with an average value of -15.6 ± 5.3‰ during December 2018. Results from two different isotope-based method showed non-agricultural sources contributed 31.2%-63.1%, with an average value of 47.5 ± 14.6%, to NH4+ and 32.3%-71.2%, with an average of 53.4 ± 16.1%, to ambient NH3 during December 2018 in Beijing. Results from CMAQ-ISAM suggest non-agricultural sources contributed on average 66.2 ± 1.9% to ambient NH4+ and 66.4 ± 1.9% to ambient NH3 during December 2018. Results from this study suggest that agricultural and non-agricultural sources nearly equally contributed to NH3 and NH4+ in urban Beijing during December 2018 with an uncertainty range of 13%-19% between isotope-based methods and CTM method.
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Affiliation(s)
- Noshan Bhattarai
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084, China
| | - Shuxiao Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084, China.
| | - Qingcheng Xu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084, China
| | - Zhaoxin Dong
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084, China
| | - Xing Chang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084, China
| | - Yueqi Jiang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084, China
| | - Haotian Zheng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, 100084, China
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7
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Kawashima H, Yoshida O, Suto N. Long-Term Source Apportionment of Ammonium in PM 2.5 at a Suburban and a Rural Site Using Stable Nitrogen Isotopes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 57:1268-1277. [PMID: 36475665 DOI: 10.1021/acs.est.2c06311] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Ammonia gas (NH3) is an important alkaline air pollutant and a precursor to particulate matter, and its source has been thought to be agricultural, but in recent years, nonagricultural sources have been suspected. In this study, stable nitrogen isotope ratios of ammonium (δ15N-NH4+) in fine particulate matter (PM2.5) were measured at a suburban site and a rural site in Japan. Then, the long-term sources of NH4+ were identified using the δ15N-NH3 and an isotopic mixing model. The results showed that the averaged contribution from nonagricultural sources was 67% at the suburban site and 78% at the rural site. We also reanalyzed NH3 data collected at the same location. The result showed that the averaged contribution of nonagricultural sources to NH3 was 39%. This result is reasonable because bottom-up estimates are close to the contribution, and the NH3 emissions are affected by warm season activities in the rural site. It was first found that the sources vary greatly, depending on the gas and particles. Back-trajectory results suggested that PM2.5 measured at the rural site was derived from the Asian continent. We inferred that the NH4+ had been formed on the continent and that these particles thus represent transboundary pollution.
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Affiliation(s)
- Hiroto Kawashima
- Department of Management Science and Engineering, Faculty of Systems Science & Technology, Akita Prefectural University, 84-4, Ebinokuchi, Tsuchiya, Yurihonjo, Akita015-0055, Japan
| | - Otoha Yoshida
- Department of Management Science and Engineering, Faculty of Systems Science & Technology, Akita Prefectural University, 84-4, Ebinokuchi, Tsuchiya, Yurihonjo, Akita015-0055, Japan
| | - Nana Suto
- Environment Research Division, Japan Automobile Research Institute, 2530 Karima, Tsukuba, Ibaraki305-0822, Japan
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