1
|
Pu T, Kong Y, Kang S, Wang S, Guo J, Jia J, Wu K, Shi X, Wang K, Sun S, Li W. Mercury export from a glacier-fed river of Mt. Meili, southeastern Tibetan Plateau. JOURNAL OF HAZARDOUS MATERIALS 2024; 477:135306. [PMID: 39067291 DOI: 10.1016/j.jhazmat.2024.135306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 07/10/2024] [Accepted: 07/21/2024] [Indexed: 07/30/2024]
Abstract
Mercury (Hg), a global contaminant, can sink into cryosphere and be released into runoff through meltwater. The Tibetan Plateau (TP) has been witnessing ongoing shrinkage of alpine glaciers. However, the export of Hg from melting glacier is still sparsely reported. From October 16, 2020 to October 15, 2021, we conducted daily observations to study the variation in total Hg concentrations and its export to the Mingyong River, a glacier-fed river in southeastern TP. Results showed that the Hg concentrations were high during the monsoon season but low during the non-monsoon period. The Hg in runoff correlated with the concentrations of total suspended particulates (TSP) and dissolved inorganic carbon (DIC) during both monsoon and non-monsoon seasons (p < 0.01), and the correlation of Hg with other parameters showed seasonal variations. The input from meltwater, precipitation, and groundwater to riverine Hg were 8.3 g, 264.4 g, and 71.0 g, respectively, and the total export was 211.0 g (yield: 4.3 g/km2/year) in the hydrological year, indicating that Mingyong catchment act as a sink for Hg. For the entire TP, the annual export of Hg from glacier runoff was estimated to be 947.7 kg/year. Our study highlights the necessity for further investigations on Hg dynamics to understand the changes in the Hg cycle within glaciated aquatic ecosystems.
Collapse
Affiliation(s)
- Tao Pu
- Yulong Snow Mountain Cryosphere and Sustainable Development Field Science Observation and Research Station/Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
| | - Yanlong Kong
- Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
| | - Shichang Kang
- Yulong Snow Mountain Cryosphere and Sustainable Development Field Science Observation and Research Station/Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Shijin Wang
- Yulong Snow Mountain Cryosphere and Sustainable Development Field Science Observation and Research Station/Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Junming Guo
- Yulong Snow Mountain Cryosphere and Sustainable Development Field Science Observation and Research Station/Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Jia Jia
- College of Geography and Environment Sciences, Zhejiang Normal University, Jinhua 321000, China
| | - Kunpeng Wu
- Yunnan University, Kunming 650000, China
| | - Xiaoyi Shi
- College of Geography and Environment Sciences, Zhejiang Normal University, Jinhua 321000, China
| | - Ke Wang
- Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Shiwei Sun
- Yulong Snow Mountain Cryosphere and Sustainable Development Field Science Observation and Research Station/Key Laboratory of Cryospheric Sciences and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Wenjie Li
- China University of Mining & Technology, Beijing, Beijing 100029, China
| |
Collapse
|
2
|
Zhang W, Li J, Qiu H, Guo X, Fei Z, Xing Y, Yin D. Distribution and bioavailability of mercury in size-fractioned atmospheric particles around an ultra-low emission power plant in Southwest China. J Environ Sci (China) 2024; 138:141-152. [PMID: 38135383 DOI: 10.1016/j.jes.2023.03.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 12/24/2023]
Abstract
Ultra-low emission (ULE) technology retrofits significantly impact the particulate-bound mercury (Hg) emissions from coal-fired power plants (CFPPs); however, the distribution and bioavailability of Hg in size-fractioned particulate matter (PM) around the ULE-retrofitted CFPPs are less understood. Here, total Hg and its chemical speciation in TSP (total suspended particles), PM10 (aerodynamic particle diameter ≤ 10 µm) and PM2.5 (aerodynamic particle diameter ≤ 2.5 µm) around a ULE-retrofitted CFPP in Guizhou Province were quantified. Atmospheric PM2.5 concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities, and it had higher mass Hg concentration than other size-fractioned PM. Total Hg concentrations in PM had multifarious sources including CFPP, vehicle exhaust and biomass combustion, while they were significantly higher in autumn and winter than those in other seasons (P < 0.05). Regardless of particulate size, atmospheric PM-bound Hg had lower residual fractions (< 21%) while higher HCl-soluble fractions (> 40%). Mass concentrations of exchangeable, HCl-soluble, elemental, and residual Hg in PM2.5 were higher than those in other size-fractioned PM, and were markedly elevated in autumn and winter (P < 0.05). In PM2.5, HCl-soluble Hg presented a significantly positive relationship with elemental Hg (P < 0.05), while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg (P < 0.01). Overall, these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM, and has higher bioavailable fractions, while has potential transformation between chemical speciation.
Collapse
Affiliation(s)
- Wei Zhang
- College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China; College of Resources and Environmental Engineering, Guizhou Institute of Technology, Guiyang 550003, China
| | - Jinjuan Li
- College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China; Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang 550025, China.
| | - Hao Qiu
- College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Xingqiang Guo
- College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Zhijun Fei
- College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing 100083, China
| | - Deliang Yin
- Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang 550025, China.
| |
Collapse
|
3
|
Božič D, Horvat M. Insights into seasonal variations in mercury isotope composition of lichens. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 340:122740. [PMID: 37865331 DOI: 10.1016/j.envpol.2023.122740] [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: 07/03/2023] [Revised: 09/24/2023] [Accepted: 10/12/2023] [Indexed: 10/23/2023]
Abstract
Lichens are commonly used to assess mercury (Hg) concentrations in air because of their cost-effectiveness. However, recent research has revealed temporal variations in the isotopic composition of Hg. Previous work on this topic leaves open questions about the repeatability of data over multiple seasons, different types of sampling (transplantation or in-situ collection), and diverse locations. This study aims to address these issues by conducting a high-frequency sampling campaign of in-situ and transplanted lichens and atmospheric particulate matter (APM). Sampling sites included a range of areas, from pristine to Hg-contaminated sites. Isotopic analysis showed that the isotopic composition of Hg in lichens undergoes mass-dependent fractionation and changes with time. The heaviest isotopic composition was observed in summer and the lightest in winter. These trends were consistent across polluted and unpolluted environments, as well as in both in-situ and transplanted lichens and in APM. The results further indicated towards a correlation between changes in Hg concentrations and isotopic composition in lichens and environmental factors. All of these variables seem to be changing at the same frequency and may have not just correlation but also causation relationship. Environmental factors seem to be influencing the Hg concentrations and isotopic composition. The summer high temperatures might be influencing the heavier isotopic fingerprint observed in lichens during the same season. Similarities with APM-bound Hg suggest a common underlying mechanism. This study highlights the importance of considering temporal and seasonal trends, as well as the method of lichen sampling, when interpreting results. Researchers using lichens as proxies for atmospheric Hg concentrations or isotope ratios should consider these findings when designing their studies.
Collapse
Affiliation(s)
- Dominik Božič
- Department of Environmental Science, Jožef Stefan Institute, Jamova Street 39, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova Street 39, Ljubljana, Slovenia
| | - Milena Horvat
- Department of Environmental Science, Jožef Stefan Institute, Jamova Street 39, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova Street 39, Ljubljana, Slovenia.
| |
Collapse
|
4
|
Sun R, Cao F, Dai S, Shan B, Qi C, Xu Z, Li P, Liu Y, Zheng W, Chen J. Atmospheric Mercury Isotope Shifts in Response to Mercury Emissions from Underground Coal Fires. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37167064 DOI: 10.1021/acs.est.2c08637] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Pollutant emissions from coal fires have caused serious concerns in major coal-producing countries. Great efforts have been devoted to suppressing them in China, notably at the notorious Wuda Coalfield in Inner Mongolia. Recent surveys revealed that while fires in this coalfield have been nearly extinguished near the surface, they persist underground. However, the impacts of Hg volatilized from underground coal fires remain unclear. Here, we measured concentrations and isotope compositions of atmospheric Hg in both gaseous and particulate phases at an urban site near the Wuda Coalfield. The atmospheric Hg displayed strong seasonality in terms of both Hg concentrations (5-7-fold higher in fall than in winter) and isotope compositions. Combining characteristic isotope compositions of potential Hg sources and air mass trajectories, we conclude that underground coal fires were still emitting large amounts of Hg into the atmosphere that have been transported to the adjacent urban area in the prevailing downwind direction. The other local anthropogenic Hg emissions were only evident in the urban atmosphere when the arriving air masses did not pass directly through the coalfield. Our study demonstrates that atmospheric Hg isotope measurement is a useful tool for detecting concealed underground coal fires.
Collapse
Affiliation(s)
- Ruoyu Sun
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Fei Cao
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Shifeng Dai
- College of Geoscience and Survey Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Bing Shan
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Cuicui Qi
- Anhui Academy of Eco-environmental Science Research, Hefei 230071, China
| | - Zhanjie Xu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Pengfei Li
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Yi Liu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Wang Zheng
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Jiubin Chen
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| |
Collapse
|
5
|
Qin X, Dong X, Tao Z, Wei R, Zhang H, Guo Q. Tracing the transboundary transport of atmospheric Particulate Bound Mercury driven by the East Asian monsoon. JOURNAL OF HAZARDOUS MATERIALS 2023; 446:130678. [PMID: 36608578 DOI: 10.1016/j.jhazmat.2022.130678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 12/13/2022] [Accepted: 12/24/2022] [Indexed: 06/17/2023]
Abstract
Taking Beijing-Tianjin-Hebei (BTH) with severe atmospheric mercury (Hg) and PM2.5 pollution as a typical region, this study clarified the characteristics and transboundary transport of atmospheric Particulate Bound Mercury (PBM2.5) affected by the East Asian monsoon. Five sampling sites were conducted in rural, suburban, urban, industrial, and coastal areas of BTH from northwest to southeast along the East Asian monsoon direction. PBM2.5 showed increasing concentrations from northwest to southeast and negative δ202Hg values, indicating significant contributions from anthropogenic sources. However, the mean Δ199Hg values of PBM2.5 at the five sites were significantly positive, probably triggered by the photoreduction of Hg(II) during long-range transport driven by the East Asian monsoon. Apart from local anthropogenic emissions as the primary sources, the transboundary transport of PBM2.5, driven by west and northwest air masses originating in Central Asia and Russia, contributed significantly to the PBM2.5 pollution of BTH. Moreover, these air masses reaching BTH would carry elevated PBM2.5 concentrations further transported to the ocean by the East Asian monsoon. In contrast, the southeast air masses transported from the ocean by the East Asian monsoon in summer diluted inland PBM2.5 pollution. This study provides insight into the atmospheric Hg circulation affected by the East Asian monsoon.
Collapse
Affiliation(s)
- Xuechao Qin
- 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; Department of Health, Ethics and Society, Care and Public Health Research Institute, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht 6229 HA, the Netherlands
| | - 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
| | - 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
| | - Rongfei Wei
- Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Hua Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, 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.
| |
Collapse
|
6
|
Nguyen LSP, Hien TT, Truong MT, Chi NDT, Sheu GR. Atmospheric particulate-bound mercury (PBM 10) in a Southeast Asia megacity: Sources and health risk assessment. CHEMOSPHERE 2022; 307:135707. [PMID: 35842046 DOI: 10.1016/j.chemosphere.2022.135707] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/04/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Particulate-bound mercury (PBM) is a global environmental concern owing to its large dry deposition velocities and scavenging coefficients, both of which drive Hg into terrestrial and marine ecosystems. PBM observation studies have been widely conducted over East Asia, but comparable studies in Peninsular Southeast Asia (PSEA) remain scarce. This is the first study reporting PBM concentrations for Ho Chi Minh City (HCMC), the biggest metropolitan area in Vietnam. A total of 222 samples were collected in 2018 and contained an average PBM10 (particulate matter - PM with diameter ≤10 μm) concentration and Hg mass fraction (i.e. PBM/PM) of 67.3 ± 45.9 pg m-3 and 1.18 ± 1.12 μg g-1, respectively. Although PBM concentration was lower than those reported in Chinese megacities, the Hg mass fraction was similar to those in China, suggesting strong enrichment from anthropogenic Hg emissions in HCMC. Traffic-induced particulate emission and deposition processes were major factors governing PBM temporal variation at our site. In addition, the prevailing southwest monsoon winds brought air masses that passed through industrial areas and were associated with a higher Hg mass fraction. Statistically significant positive correlations (R2 = 0.11-0.52, p < 0.01) were observed for PBM with PM and the Hg mass fraction, indicating similar PM and Hg sources or oxidized Hg adsorption onto PM via gas-particle partitioning. Moreover, PCA results revealed a higher contribution of primary sources than secondary sources to PBM concentration variability in HCMC. A health risk assessment indicated that the PBM concentrations at HCMC posed minimal non-carcinogenic risks (HI < 1) for children and adults, but dermal contact may act as an important exposure route since lightweight clothing is common among residents. This PBM dataset over PSEA, a region with high atmospheric Hg emissions, provides a valuable resource for the Hg scientific community to improve our understanding of Hg biogeochemical cycle.
Collapse
Affiliation(s)
- Ly Sy Phu Nguyen
- Faculty of Environment, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam.
| | - To Thi Hien
- Faculty of Environment, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam
| | - Minh Tri Truong
- Faculty of Environment, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam
| | - Nguyen Doan Thien Chi
- Faculty of Environment, University of Science, Ho Chi Minh City, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam
| | - Guey-Rong Sheu
- Department of Atmospheric Sciences, National Central University, Taoyuan, Taiwan; Center for Environmental Monitoring and Technology, National Central University, Taoyuan, Taiwan.
| |
Collapse
|
7
|
Bhattarai H, Tripathee L, Kang S, Chen P, Sharma CM, Ram K, Guo J, Rupakheti M. Nitrogenous and carbonaceous aerosols in PM 2.5 and TSP during pre-monsoon: Characteristics and sources in the highly polluted mountain valley. J Environ Sci (China) 2022; 115:10-24. [PMID: 34969440 DOI: 10.1016/j.jes.2021.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 06/09/2021] [Accepted: 06/20/2021] [Indexed: 06/14/2023]
Abstract
This study reports for the first time a comprehensive analysis of nitrogenous and carbonaceous aerosols in simultaneously collected PM2.5 and TSP during pre-monsoon (March-May 2018) from a highly polluted urban Kathmandu Valley (KV) of the Himalayan foothills. The mean mass concentration of PM2.5 (129.8 µg/m3) was only ~25% of TSP mass (558.7 µg/ m3) indicating the dominance of coarser mode aerosols. However, the mean concentration as well as fractional contributions of water-soluble total nitrogen (WSTN) and carbonaceous species reveal their predominance in find-mode aerosols. The mean mass concentration of WSTN was 17.43±4.70 µg/m3 (14%) in PM2.5 and 24.64±8.07 µg/m3 (5%) in TSP. Moreover, the fractional contribution of total carbonaceous aerosols (TCA) is much higher in PM2.5 (~34%) than that in TSP (~20%). The relatively low OC/EC ratio in PM2.5 (3.03 ± 1.47) and TSP (4.64 ± 1.73) suggests fossil fuel combustion as the major sources of carbonaceous aerosols with contributions from secondary organic aerosols. Five-day air mass back trajectories simulated with the HYSPLIT model, together with MODIS fire counts indicate the influence of local emissions as well as transported pollutants from the Indo-Gangetic Plain region to the south of the Himalayan foothills. Principal component analysis (PCA) also suggests a mixed contribution from other local anthropogenic, biomass burning, and crustal sources. Our results highlight that it is necessary to control local emissions as well as regional transport while designing mitigation measures to reduce the KV's air pollution.
Collapse
Affiliation(s)
- Hemraj Bhattarai
- Earth System Science Programme and Graduate Division of Earth and Atmospheric Sciences, The Chinese University of Hong Kong, Hong Kong, China; Himalayan Environment Research Institute (HERI), Kathmandu 44602, Nepal
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu 44602, Nepal.
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Chhatra Mani Sharma
- Himalayan Environment Research Institute (HERI), Kathmandu 44602, Nepal; Central Department of Environmental Sciences, Tribhuvan University, Kathmandu 44613, Nepal
| | - Kirpa Ram
- Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221005, India
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | | |
Collapse
|
8
|
Liu C, Fu X, Xu Y, Zhang H, Wu X, Sommar J, Zhang L, Wang X, Feng X. Sources and Transformation Mechanisms of Atmospheric Particulate Bound Mercury Revealed by Mercury Stable Isotopes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5224-5233. [PMID: 35385257 DOI: 10.1021/acs.est.1c08065] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This study examined the isotopic composition of particulate bound mercury (PBM) in 10 Chinese megacities and explored the associated sources and transformation mechanisms. PBM in these cities was characterized by negative δ202Hg (mean: -2.00 to -0.78‰), slightly negative to highly positive Δ199Hg (mean: -0.04 to 0.47‰), and slightly positive Δ200Hg (mean: 0.02 to 0.06‰) values. The positive PBM Δ199Hg signatures were likely caused by physiochemical reactions in aerosols. The Δ199Hg/Δ201Hg ratio varied from 0.94 to 1.39 in the cities and increased with the increase in the corresponding mean Δ199HgPBM value. We speculate that, in addition to the photoreduction of oxidized Hg, other transformation mechanisms in aerosols (e.g., isotope exchange, complexation, and oxidation, which express nuclear volume effects) also shape the Δ199HgPBM signatures in the present study. These processes are likely enhanced in the presence of strong gas-particle partitioning of gaseous oxidized Hg (GOM) and elevated levels of redox active metals (e.g., Fe), halides, and elemental carbon. Based on Δ200HgPBM data presented in this and previous studies, we estimate that large proportions (∼47 ± 22%) of PBM were sourced from the oxidation of gaseous elemental Hg followed by the partitioning of GOM onto aerosols globally, indicating the transformation of Hg(0) to PBM as an important sink of atmospheric Hg(0).
Collapse
Affiliation(s)
- Chen Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuewu Fu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Yue Xu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Hui Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xian Wu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jonas Sommar
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Leiming Zhang
- Air Quality Research Division, Science and Technology Branch, Environment and Climate Change Canada, Toronto M3H 5T4, Ontario, Canada
| | - Xun Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|