1
|
Yoo H, Seo D, Shin D, Ro CU. Direct Observation of Particle-To-Particle Variability in Ambient Aerosol pH Using a Novel Analytical Approach Based on Surface-Enhanced Raman Spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:7977-7985. [PMID: 38664901 DOI: 10.1021/acs.est.4c00220] [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: 05/08/2024]
Abstract
The pH of atmospheric aerosols is a key characteristic that profoundly influences their impacts on climate change, human health, and ecosystems. Despite widely performed aerosol pH research, determining the pH levels of individual atmospheric aerosol particles has been a challenge. This study presents a novel analytical technique that utilizes surface-enhanced Raman spectroscopy to assess the pH of individual ambient PM2.5-10 aerosol particles in conjunction with examining their hygroscopic behavior, morphology, and elemental compositions. The results revealed a substantial pH variation among simultaneously collected aerosol particles, ranging from 3.3 to 5.7. This variability is likely related to each particle's unique reaction and aging states. The extensive particle-to-particle pH variability suggests that atmospheric aerosols present at the same time and location can exhibit diverse reactivities, reaction pathways, phase equilibria, and phase separation properties. This pioneering study paves the way for in-depth investigations into particle-to-particle variability, size dependency, and detailed spatial and temporal variations of aerosol pH, thus deepening our understanding of atmospheric chemistry and its environmental implications.
Collapse
Affiliation(s)
- Hanjin Yoo
- Department of Chemistry, Inha University, Incheon 22212, Republic of Korea
- Particle Pollution Management Center, Inha University, Incheon 21999, Republic of Korea
| | - Dongkwon Seo
- Department of Chemistry, Inha University, Incheon 22212, Republic of Korea
| | - Dongha Shin
- Department of Chemistry, Inha University, Incheon 22212, Republic of Korea
| | - Chul-Un Ro
- Department of Chemistry, Inha University, Incheon 22212, Republic of Korea
- Particle Pollution Management Center, Inha University, Incheon 21999, Republic of Korea
| |
Collapse
|
2
|
Wu Z, Wang H, Yin Y, Shen L, Chen K, Chen J, Zhen Z, Cui Y, Ke Y, Liu S, Zhao T, Lin W. Impacts of the aerosol mixing state and new particle formation on CCN in summer at the summit of Mount Tai (1534m) in Central East China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170622. [PMID: 38325490 DOI: 10.1016/j.scitotenv.2024.170622] [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: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/09/2024]
Abstract
In this study, the aerosol size distributions, cloud condensation nuclei (CCN) number concentration (NCCN), single-particle chemical composition and meteorological data were collected from May 12 to June 8, 2017, at the summit of Mt. Tai. The effects of new particle formation (NPF) events and aerosol chemical components on CCN at Mt. Tai were analyzed in detail. The results showed that, NPF events significantly enhanced the CCN population, and the enhancement effect increased with increasing supersaturation (SS) value at Mt.Tai. NCCN at SS ranging from 0.1 to 0.9 % on NPF days was 10.9 %, 36.5 %, 44.6 %, 53.5 % and 51.5 % higher than that on non-NPF days from 10:00-13:00 as NPF events progressed. The effect of chemical components on CCN activation under the influence of NPF events was greater than that in the absence of NPF events. The correlation coefficients of EC-Nitrate particles (EC-Sulfate particles) and CCN at all SS levels on NPF days were 1.31-1.59 times (1.17-1.35 times) higher than those on non-NPF days. Nitrate particles promoted CCN activation but sulfate particles inhibited activation at Mt. Tai. There are differences or even opposite effects of the same group of particles on CCN activation under the influence of NPF events in different air masses. EC-Sulfate particles inhibited CCN activation at all SS levels for type I but weakly promoted activation at lower SS ranging from 0.1 to 0.3 % and weakly inhibited it at higher 0.9 % SS for type II. OCEC particles significantly inhibited CCN activation for type II, and this effect decreased with increasing SS. OCEC particles only weakly inhibited activation at SS ranging from 0.5 to 0.7 % for type I. OCEC particles only weakly inhibited this process at 0.1 % SS, while they very weakly promoted activation for SS > 0.1 %. This reveals that the CCN activity is not only related to the chemical composition of the particles, but the mixing state also has an important effect on the CCN activity.
Collapse
Affiliation(s)
- Zihao Wu
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Honglei Wang
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China; Fujian Key Laboratory of Severe Weather and Key Laboratory of Straits Severe Weather, China Meteorological Administration, Fuzhou 350001, China.
| | - Yan Yin
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Lijuan Shen
- School of Atmosphere and Remote Sensing, Wuxi University, Wuxi 214105, China
| | - Kui Chen
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Jinghua Chen
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Zhongxiu Zhen
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Yi Cui
- Weather Modification Center of Hebei Province, Shijiazhuang 050022, China
| | - Yue Ke
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Sihan Liu
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Tianliang Zhao
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Wen Lin
- Fujian Key Laboratory of Severe Weather and Key Laboratory of Straits Severe Weather, China Meteorological Administration, Fuzhou 350001, China
| |
Collapse
|
3
|
Phan CM. Affinity of Amphiphilic Molecules to Air/Water Surface. ACS OMEGA 2023; 8:47928-47937. [PMID: 38144045 PMCID: PMC10733914 DOI: 10.1021/acsomega.3c06512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/21/2023] [Accepted: 11/24/2023] [Indexed: 12/26/2023]
Abstract
The affinity of amphiphiles to the water/air surface was modeled by adapting Eberhart's equation. The proposed method successfully describes surface tension for all amphiphilic structures, including alkanols, carboxylic acids, nonionic, ionic, and Gemini surfactants. The model is more effective than conventional analysis for amphiphiles with multiple ionic states. The prediction was consistently validated at different temperatures and nonaqueous solvents. The modeling results show a linear correlation between surface affinity and hydrophobicity/hydrophilicity. For alkanols, the affinity increment is 2.84 kJ/mol per CH2 group, the same as the reported hydrophobic energy from monomer to aggregate for nonionic surfactants. For carboxylic acids, the affinity increment per CH2 group is 3.18 kJ/mol, incorporating the degree of acid dissociation. The affinity-hydrophilicity correlation is approximately -0.22 kJ/mol per oxyethylene group. The affinity constant can be obtained for all classes of amphiphiles to clarify the relationship between the molecular structure and surface activity.
Collapse
Affiliation(s)
- Chi Minh Phan
- Discipline of Chemical Engineering,
WASM:MECE, Curtin University, Perth, Western Australia 6845, Australia
| |
Collapse
|
4
|
Malek K, Gohil K, Olonimoyo EA, Ferdousi-Rokib N, Huang Q, Pitta KR, Nandy L, Voss KA, Raymond TM, Dutcher DD, Freedman MA, Asa-Awuku A. Liquid-Liquid Phase Separation Can Drive Aerosol Droplet Growth in Supersaturated Regimes. ACS ENVIRONMENTAL AU 2023; 3:348-360. [PMID: 38028744 PMCID: PMC10655592 DOI: 10.1021/acsenvironau.3c00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/31/2023] [Accepted: 07/31/2023] [Indexed: 12/01/2023]
Abstract
It is well known that atmospheric aerosol size and composition impact air quality, climate, and health. The aerosol composition is typically a mixture and consists of a wide range of organic and inorganic particles that interact with each other. Furthermore, water vapor is ubiquitous in the atmosphere, in indoor air, and within the human body's respiratory system, and the presence of water can alter the aerosol morphology and propensity to form droplets. Specifically, aerosol mixtures can undergo liquid-liquid phase separation (LLPS) in the presence of water vapor. However, the experimental conditions for which LLPS impacts water uptake and the subsequent prediction of aerosol mixtures are poorly understood. To improve our understanding of aerosol mixtures and droplets, this study explores two ternary systems that undergo LLPS, namely, the 2MGA system (sucrose + ammonium sulfate + 2-methylglutaric acid) and the PEG1000 system (sucrose + ammonium sulfate + polyethylene glycol 1000). In this study, the ratio of species and the O:C ratios are systematically changed, and the hygroscopic properties of the resultant aerosol were investigated. Here, we show that the droplet activation above 100% RH of the 2MGA system was influenced by LLPS, while the droplet activation of the PEG1000 system was observed to be linearly additive regardless of chemical composition, O:C ratio, and LLPS. A theoretical model that accounts for LLPS with O:C ratios was developed and predicts the water uptake of internally mixed systems of different compositions and phase states. Hence, this study provides a computationally efficient algorithm to account for the LLPS and solubility parameterized by the O:C ratio for droplet activation at supersaturated relative humidity conditions and may thus be extended to mixed inorganic-organic aerosol populations with unspeciated organic composition found in the ambient environment.
Collapse
Affiliation(s)
- Kotiba Malek
- Department
of Chemical and Biomolecular Engineering, University of Maryland, College
Park, Maryland 20742, United States
| | - Kanishk Gohil
- Department
of Chemical and Biomolecular Engineering, University of Maryland, College
Park, Maryland 20742, United States
| | - Esther A. Olonimoyo
- Department
of Chemistry and Biochemistry, University
of Maryland, College Park, Maryland 20742, United States
| | - Nahin Ferdousi-Rokib
- Department
of Chemical and Biomolecular Engineering, University of Maryland, College
Park, Maryland 20742, United States
| | - Qishen Huang
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kiran R. Pitta
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Lucy Nandy
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Katelyn A. Voss
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Timothy M. Raymond
- Department
of Chemical Engineering, Bucknell University, Lewisburg, Pennsylvania 17837, United States
| | - Dabrina D Dutcher
- Department
of Chemical Engineering, Bucknell University, Lewisburg, Pennsylvania 17837, United States
- Department
of Chemistry, Bucknell University, Lewisburg, Pennsylvania 17837, United States
| | - Miriam Arak Freedman
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department
of Meteorology and Atmospheric Science, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Akua Asa-Awuku
- Department
of Chemical and Biomolecular Engineering, University of Maryland, College
Park, Maryland 20742, United States
- Department
of Chemistry and Biochemistry, University
of Maryland, College Park, Maryland 20742, United States
| |
Collapse
|
5
|
Wang T, Kalalian C, Fillion D, Perrier S, Chen J, Domine F, Zhang L, George C. Sunlight Induces the Production of Atmospheric Volatile Organic Compounds (VOCs) from Thermokarst Ponds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:17363-17373. [PMID: 37903215 DOI: 10.1021/acs.est.3c03303] [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: 11/01/2023]
Abstract
Ground subsidence caused by permafrost thawing causes the formation of thermokarst ponds, where organic compounds from eroding permafrost accumulate. We photolyzed water samples from two such ponds in Northern Quebec and discovered the emission of volatile organic compounds (VOCs) using mass spectrometry. One pond near peat-covered permafrost mounds was organic-rich, while the other near sandy mounds was organic-poor. Compounds up to C10 were detected, comprising the atoms of O, N, and S. The main compounds were methanol, acetaldehyde, and acetone. Hourly VOC fluxes under actinic fluxes similar to local solar fluxes might reach up to 1.7 nmol C m-2 s-1. Unexpectedly, the fluxes of VOCs from the organic-poor pond were greater than those from the organic-rich pond. We suggest that different segregations of organics at the air/water interface may partly explain this observation. This study indicates that sunlit thermokarst ponds are a significant source of atmospheric VOCs, which may affect the environment and climate via ozone and aerosol formation. Further work is required for understanding the relationship between the pond's organic composition and VOC emission fluxes.
Collapse
Affiliation(s)
- Tao Wang
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, 69626 Villeurbanne, France
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China
| | - Carmen Kalalian
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, 69626 Villeurbanne, France
| | - Daniel Fillion
- Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), Pavillon Alexandre-Vachon, Québec G1V 0A6, Canada
- Centre d'Études Nordiques, Université Laval, Pavillon Abitibi-Price, Québec G1 V 0A6, Canada
- Department of Chemistry, Université Laval, Pavillon Alexandre-Vachon, Québec G1 V 0A6, Canada
| | - Sébastien Perrier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, 69626 Villeurbanne, France
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China
| | - Florent Domine
- Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), Pavillon Alexandre-Vachon, Québec G1V 0A6, Canada
- Centre d'Études Nordiques, Université Laval, Pavillon Abitibi-Price, Québec G1 V 0A6, Canada
- Department of Chemistry, Université Laval, Pavillon Alexandre-Vachon, Québec G1 V 0A6, Canada
| | - Liwu Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China
| | - Christian George
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, 69626 Villeurbanne, France
| |
Collapse
|
6
|
Yao M, Zhao Y, Chang C, Wang S, Li Z, Li C, Chan AWH, Xiao H. Multiphase Reactions between Organic Peroxides and Sulfur Dioxide in Internally Mixed Inorganic and Organic Particles: Key Roles of Particle Phase Separation and Acidity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15558-15570. [PMID: 37797208 DOI: 10.1021/acs.est.3c04975] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Organic peroxides (POs) are ubiquitous in the atmosphere and particularly reactive toward dissolved sulfur dioxide (SO2), yet the reaction kinetics between POs and SO2, especially in complex inorganic-organic mixed particles, remain poorly constrained. Here, we report the first investigation of the multiphase reactions between SO2 and POs in monoterpene-derived secondary organic aerosol internally mixed with different inorganic salts (ammonium sulfate, ammonium bisulfate, or sodium nitrate). We find that when the particles are phase-separated, the PO-S(IV) reactivity is consistent with that measured in pure SOA and depends markedly on the water content in the organic shell. However, when the organic and inorganic phases are miscible, the PO-S(IV) reactivity varies substantially among different aerosol systems, mainly driven by their distinct acidities (not by ionic strength). The second-order PO-S(IV) rate constant decreases monotonically from 5 × 105 to 75 M-1 s-1 in the pH range of 0.1-5.6. Both proton catalysis and general acid catalysis contribute to S(IV) oxidation, with their corresponding third-order rate constants determined to be (6.4 ± 0.7) × 106 and (6.9 ± 4.6) × 104 M-2 s-1 at pH 2-6, respectively. The measured kinetics imply that the PO-S(IV) reaction in aerosol is an important sulfate formation pathway, with the reaction kinetics dominated by general acid catalysis at pH > 3 under typical continental atmospheric conditions.
Collapse
Affiliation(s)
- Min Yao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
- School of Environmental & Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Yue Zhao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chongxuan Chang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Shunyao Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Ziyue Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chenxi Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Huayun Xiao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| |
Collapse
|
7
|
Lee WC, Liu P, Han Y, Martin ST, Kuwata M. Accounting for Cloud Nucleation Activation Mechanism of Secondary Organic Matter from α-Pinene Oxidation Using Experimentally Retrieved Water Solubility Distributions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13439-13448. [PMID: 37647587 DOI: 10.1021/acs.est.3c03039] [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: 09/01/2023]
Abstract
Activation of cloud droplets of aerosol particles from biogenic precursors plays a critical role in Earth's climate system. However, the molecular-level understanding of the cloud condensation nuclei (CCN) activation process for secondary organic matter (SOM) is still lacking. Here, we reduced the gap by segregating SOM from α-pinene based on water solubility. The chemical composition and CCN activity of the solubility-segregated fractions of SOM were measured. The results demonstrated for the first time by laboratory experiment that highly oxygenated compounds such as hydroperoxides and highly oxygenated organic molecules are important contributors for the CCN activity of α-pinene SOM. Meanwhile, relatively less water-soluble species were also abundant. Analysis based on the Köhler theory demonstrated that less water-soluble compounds in SOM remain undissolved during the cloud activation process, suggesting that the traditional single-parameter parameterization for CCN activation would not be sufficient for representing the process. In combination with the recent developments in SOM formation chemistry, the present study helps in understanding the interactions between the biosphere and climate.
Collapse
Affiliation(s)
- Wen-Chien Lee
- Department of Atmospheric and Oceanic Sciences, Laboratory for Climate and Ocean-Atmosphere Studies, Peking University, Beijing 100871, China
- Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), Peking University, Beijing 100871, China
- Division of Chemistry and Biochemistry, Nanyang Technological University, Singapore 639798, Singapore
- Earth Observatory of Singapore, Nanyang Technological University, Singapore 639798, Singapore
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Pengfei Liu
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Yuemei Han
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Scot T Martin
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Mikinori Kuwata
- Department of Atmospheric and Oceanic Sciences, Laboratory for Climate and Ocean-Atmosphere Studies, Peking University, Beijing 100871, China
- Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), Peking University, Beijing 100871, China
- Division of Chemistry and Biochemistry, Nanyang Technological University, Singapore 639798, Singapore
- Earth Observatory of Singapore, Nanyang Technological University, Singapore 639798, Singapore
- Campus for Research Excellence and Technological Enterprise (CREATE) Programme, Singapore 138602, Singapore
| |
Collapse
|
8
|
Müller S, Giorio C, Borduas-Dedekind N. Tracking the Photomineralization Mechanism in Irradiated Lab-Generated and Field-Collected Brown Carbon Samples and Its Effect on Cloud Condensation Nuclei Abilities. ACS ENVIRONMENTAL AU 2023; 3:164-178. [PMID: 37215437 PMCID: PMC10197166 DOI: 10.1021/acsenvironau.2c00055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 03/02/2023] [Accepted: 03/02/2023] [Indexed: 05/24/2023]
Abstract
Organic aerosols affect the planet's radiative balance by absorbing and scattering light as well as by activating cloud droplets. These organic aerosols contain chromophores, termed brown carbon (BrC), and can undergo indirect photochemistry, affecting their ability to act as cloud condensation nuclei (CCN). Here, we investigated the effect of photochemical aging by tracking the conversion of organic carbon into inorganic carbon, termed the photomineralization mechanism, and its effect on the CCN abilities in four different types of BrC samples: (1) laboratory-generated (NH4)2SO4-methylglyoxal solutions, (2) dissolved organic matter isolate from Suwannee River fulvic acid (SRFA), (3) ambient firewood smoke aerosols, and (4) ambient urban wintertime particulate matter in Padua, Italy. Photomineralization occurred in all BrC samples albeit at different rates, evidenced by photobleaching and by loss of organic carbon up to 23% over a simulated 17.6 h of sunlight exposure. These losses were correlated with the production of CO up to 4% and of CO2 up to 54% of the initial organic carbon mass, monitored by gas chromatography. Photoproducts of formic, acetic, oxalic and pyruvic acids were also produced during irradiation of the BrC solutions, but at different yields depending on the sample. Despite these chemical changes, CCN abilities did not change substantially for the BrC samples. In fact, the CCN abilities were dictated by the salt content of the BrC solution, trumping a photomineralization effect on the CCN abilities for the hygroscopic BrC samples. Solutions of (NH4)2SO4-methylglyoxal, SRFA, firewood smoke, and ambient Padua samples had hygroscopicity parameters κ of 0.6, 0.1, 0.3, and 0.6, respectively. As expected, the SRFA solution with a κ of 0.1 was most impacted by the photomineralization mechanism. Overall, our results suggest that the photomineralization mechanism is expected in all BrC samples and can drive changes in the optical properties and chemical composition of aging organic aerosols.
Collapse
Affiliation(s)
- Silvan Müller
- Department
of Environmental Systems Science, ETH Zurich, Zurich 8092, Switzerland
| | - Chiara Giorio
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, United
Kingdom
- Department
of Chemical Sciences, University of Padova, Padova 35131, Italy
| | - Nadine Borduas-Dedekind
- Department
of Environmental Systems Science, ETH Zurich, Zurich 8092, Switzerland
- Department
of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| |
Collapse
|
9
|
Wei L, Zhu T, Guo Y, Ni C. MMST: A Multi-Modal Ground-Based Cloud Image Classification Method. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23094222. [PMID: 37177425 PMCID: PMC10180870 DOI: 10.3390/s23094222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 04/19/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023]
Abstract
In recent years, convolutional neural networks have been in the leading position for ground-based cloud image classification tasks. However, this approach introduces too much inductive bias, fails to perform global modeling, and gradually tends to saturate the performance effect of convolutional neural network models as the amount of data increases. In this paper, we propose a novel method for ground-based cloud image recognition based on the multi-modal Swin Transformer (MMST), which discards the idea of using convolution to extract visual features and mainly consists of an attention mechanism module and linear layers. The Swin Transformer, the visual backbone network of MMST, enables the model to achieve better performance in downstream tasks through pre-trained weights obtained from the large-scale dataset ImageNet and can significantly shorten the transfer learning time. At the same time, the multi-modal information fusion network uses multiple linear layers and a residual structure to thoroughly learn multi-modal features, further improving the model's performance. MMST is evaluated on the multi-modal ground-based cloud public data set MGCD. Compared with the state-of-art methods, the classification accuracy rate reaches 91.30%, which verifies its validity in ground-based cloud image classification and proves that in ground-based cloud image recognition, models based on the Transformer architecture can also achieve better results.
Collapse
Affiliation(s)
- Liang Wei
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Tingting Zhu
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Yiren Guo
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Chao Ni
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
| |
Collapse
|
10
|
Ray A, Pandithurai G, Mukherjee S, Kumar VA, Hazra A, Patil RD, Waghmare V. Seasonal variability in size-resolved hygroscopicity of sub-micron aerosols over the Western Ghats, India: Closure and parameterization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161753. [PMID: 36690110 DOI: 10.1016/j.scitotenv.2023.161753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 06/17/2023]
Abstract
Hygroscopicity of atmospheric aerosol primarily depends on the size and chemical composition of the particle and is important for estimating anthropogenic aerosol radiative forcing. There is limited information exists over the Indian region on size segregated aerosol hygroscopicity (κ) in different seasons. This study presents 'κ' as derived from a Humidified Tandem Differential Mobility Analyzer (HTDMA) over a High Altitude Cloud Physics Laboratory (HACPL) in the Western Ghats, India for more than a year (from May 2019 to May 2020). The average hygroscopicity values of aerosol particles of diameters 32, 50, 75, 110, 150, 210 and 260 nm at 90 % RH condition are 0.19, 0.18, 0.16, 0.17, 0.18, 0.20, 0.21 respectively during the entire observation period. κ was observed to decrease with an increase in size in the Aitken mode regime (32-75 nm) and an increase in the accumulation mode (110-260 nm). Seasonal variation of hygroscopicity for a wide range of particle diameters is reported which is highly demanding as there is a change in the air mass flow pattern in each of the seasons. The diurnal cycle of hygroscopicity showed a prominent peak during the midnight to early morning hours followed by a decrease in the forenoon hours and a secondary peak in the afternoon hours. κ is found to be higher in pre-monsoon compared to winter season as Chl is approximately 3 % higher in pre-monsoon and NH4Cl is highly hygroscopic among the assumed chemical composition. Hygroscopicity derived through chemical speciation observations assuming internal and external mixing of aerosols i.e. κinter and κexter are overestimating as compared to κHTDMA. However, the bias between kexter and kHTDMA is relatively lower as external mixing type of aerosol is evident through the growth factor data sets measured by HTDMA. Utilizing the hygroscopicity measurements available for discrete diameters by HTDMA, a parameterization of hygroscopicity with the dry diameter of sub-micron particles is developed.
Collapse
Affiliation(s)
- Avishek Ray
- Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, India; Savitribai Phule Pune University, Pune, India
| | - G Pandithurai
- Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, India.
| | - S Mukherjee
- Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, India
| | - V Anil Kumar
- Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, India
| | - A Hazra
- Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, India
| | - Rohit D Patil
- Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, India
| | - V Waghmare
- Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, India
| |
Collapse
|
11
|
Faust JA. PFAS on atmospheric aerosol particles: a review. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:133-150. [PMID: 35416231 DOI: 10.1039/d2em00002d] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants of concern to human health. These synthetic chemicals are in widespread use for consumer products, firefighting foams, and industrial applications. They have been detected all over the globe, including at remote locations distant from any possible point sources. One mechanism for long-range transport of PFAS is through sorption to aerosol particles in the atmosphere. PFAS can be transferred from the sea surface to sea spray aerosol particles through wave breaking and bubble bursting, and PFAS emitted to the atmosphere in the gas phase can sorb to particulate matter through gas-particle partitioning. Here we present a comprehensive review of global measurements of PFAS on ambient particulate matter dating back to the first reports from the early 2000s. We summarize findings for the historically important C8 species, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), including detection of isomers and size-segregated measurements, as well as studies of newer and emerging PFAS. We conclude that long-term monitoring of PFAS on particulate matter should be expanded to include more measurement sites in under-sampled regions of the world and that further non-targeted work to identify novel PFAS structures is needed as PFAS manufacturing and regulations continue to evolve.
Collapse
Affiliation(s)
- Jennifer A Faust
- Department of Chemistry, The College of Wooster, Wooster, OH, USA.
| |
Collapse
|
12
|
Peng C, Deng C, Lei T, Zheng J, Zhao J, Wang D, Wu Z, Wang L, Chen Y, Liu M, Jiang J, Ye A, Ge M, Wang W. Measurement of atmospheric nanoparticles: Bridging the gap between gas-phase molecules and larger particles. J Environ Sci (China) 2023; 123:183-202. [PMID: 36521983 DOI: 10.1016/j.jes.2022.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 06/17/2023]
Abstract
Atmospheric nanoparticles are crucial components contributing to fine particulate matter (PM2.5), and therefore have significant effects on visibility, climate, and human health. Due to the unique role of atmospheric nanoparticles during the evolution process from gas-phase molecules to larger particles, a number of sophisticated experimental techniques have been developed and employed for online monitoring and characterization of the physical and chemical properties of atmospheric nanoparticles, helping us to better understand the formation and growth of new particles. In this paper, we firstly review these state-of-the-art techniques for investigating the formation and growth of atmospheric nanoparticles (e.g., the gas-phase precursor species, molecular clusters, physicochemical properties, and chemical composition). Secondly, we present findings from recent field studies on the formation and growth of atmospheric nanoparticles, utilizing several advanced techniques. Furthermore, perspectives are proposed for technique development and improvements in measuring atmospheric nanoparticles.
Collapse
Affiliation(s)
- Chao Peng
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Chenjuan Deng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Ting Lei
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Zheng
- School of Environment Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Jun Zhao
- School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai, Guangdong 519082, China
| | - Dongbin Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Zhijun Wu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Lin Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China
| | - Yan Chen
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingyuan Liu
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingkun Jiang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Anpei Ye
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China
| | - Maofa Ge
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weigang Wang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
13
|
Lee WC, Deng Y, Zhou R, Itoh M, Mochida M, Kuwata M. Water Solubility Distribution of Organic Matter Accounts for the Discrepancy in Hygroscopicity among Sub- and Supersaturated Humidity Regimes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:17924-17935. [PMID: 36346950 DOI: 10.1021/acs.est.2c04647] [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: 06/16/2023]
Abstract
Water uptake properties of organic matter (OM) are critical for aerosol direct and indirect effects. OM contains various chemical species that have a wide range of water solubility. However, the role of water solubility on water uptake by OM has poorly been investigated. We experimentally retrieved water solubility distributions of water-soluble OM (WSOM) from combustion of mosquito coil and tropical peat using the 1-octanol-water partitioning method. In addition, hygroscopic growth and cloud condensation nuclei (CCN) activity of solubility-segregated WSOM were measured. The dominant fraction of WSOM from mosquito coil smoldering was highly soluble (water solubility (S) > 10-2 g cm-3), while that from peat combustion contained ∼40% of less-soluble species (S < 10-3 g cm-3). The difference in water solubility distributions induced changes in the roles of less water-soluble fractions (S < 10-3 g cm-3) on CCN activity. Namely, the less water-soluble fraction from mosquito coil combustion fully dissolved at the point of critical supersaturation, while that for tropical peat smoldering was limited by water solubility. The present result suggests that water solubility distributions of OM, rather than its bulk chemical property, need to be quantified for understanding the water uptake process.
Collapse
Affiliation(s)
- Wen-Chien Lee
- Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing100871, China
- Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), Peking University, Beijing100871, China
- Laboratory for Climate and Ocean-Atmosphere Studies, School of Physics, Peking University, Beijing100871, China
- Division of Chemistry and Biochemistry, Nanyang Technological University, 639798Singapore
- Earth Observatory of Singapore, Nanyang Technological University, 639798Singapore
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya464-8601, Japan
| | - Yange Deng
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya464-8601, Japan
| | - Ruichen Zhou
- Graduate School of Environmental Studies, Nagoya University, Nagoya464-8601, Japan
| | - Masayuki Itoh
- School of Human Science and Environment, University of Hyogo, Hyogo651-2103, Japan
- Center for Southeast Asian Studies, Kyoto University, Kyoto606-8501, Japan
| | - Michihiro Mochida
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya464-8601, Japan
- Graduate School of Environmental Studies, Nagoya University, Nagoya464-8601, Japan
| | - Mikinori Kuwata
- Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing100871, China
- Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), Peking University, Beijing100871, China
- Laboratory for Climate and Ocean-Atmosphere Studies, School of Physics, Peking University, Beijing100871, China
- Earth Observatory of Singapore, Nanyang Technological University, 639798Singapore
- Asian School of Environment, Nanyang Technological University, 639798Singapore
- Campus for Research Excellence and Technological Enterprise (CREATE) Programme, 138602Singapore
| |
Collapse
|
14
|
Liu J, Zhang T, Ding X, Li X, Liu Y, Yan C, Shen Y, Yao X, Zheng M. A clear north-to-south spatial gradience of chloride in marine aerosol in Chinese seas under the influence of East Asian Winter Monsoon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 832:154929. [PMID: 35367263 DOI: 10.1016/j.scitotenv.2022.154929] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/23/2022] [Accepted: 03/26/2022] [Indexed: 06/14/2023]
Abstract
Particulate chloride is a major component of sea salt particles and plays a key role in atmospheric chemistry. Anthropogenic pollutants over the northeastern Asia can be transported to the adjacent seas through the northwest monsoon, which profoundly influences the chloride chemistry over the seas. In this study, spatial distribution of particulate chloride and its sources over the Chinese seas were investigated based on shipboard particle samplings especially online Single Particle Aerosol Mass Spectrometer (SPAMS) over Bohai Sea, North Yellow Sea, and South Yellow Sea (SYS) during a cruise in November 2012. A strong north-to-south (N-S) gradience in marine aerosol composition was found. The Cl-/Na+ ratios in PM2.5 and single particle composition by SPAMS indicated remarkable chloride enrichment in marine aerosol in the north (Bohai Sea), while depletion in southern SYS. The results of size distribution showed that particulate chloride had higher concentration in coarse particles, while the Cl-/Na+ ratio was much higher in submicron particles. In the north (38-40°N), biomass burning, carbonaceous, and Pb-rich type particles had high fractions in all chloride-containing particles identified by SPAMS (on average 66%). Combining chemical composition with back trajectory, it was found that fine-mode chloride enrichment in the north was mainly due to anthropogenic emission especially coal combustion and biomass burning from northern China. However, the high fine-mode chloride depletion in the south (32-34°N) was probably due to acid replacement by sulfate in aged aerosol during atmospheric transport. Our new findings reveal that marine aerosol in Chinese seas would show a clear N-S pattern of more fresh and anthropogenic enriched particles in the north, but more aged aerosol in the south during the East Asia Winter Monsoon, which provides new insights for the quantitative assessment of anthropogenic impact on marine aerosol and future modeling study.
Collapse
Affiliation(s)
- Junyi Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Tianle Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xiang Ding
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaoying Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yue Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Caiqing Yan
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Yanjie Shen
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Qingdao, China
| | - Xiaohong Yao
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Qingdao, China
| | - Mei Zheng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| |
Collapse
|
15
|
Peng C, Malek KA, Rastogi D, Zhang Y, Wang W, Ding X, Asa-Awuku AA, Wang X, Tang M. Hygroscopicity and cloud condensation nucleation activities of hydroxyalkylsulfonates. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 830:154767. [PMID: 35346709 DOI: 10.1016/j.scitotenv.2022.154767] [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: 02/12/2022] [Revised: 03/07/2022] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
Hydroxyalkylsulfonates may contribute significantly to atmospheric particles; however, their hygroscopic properties and cloud condensation nuclei (CCN) activities remain unknown. In this study, three complementary techniques were utilized to examine the hygroscopicity of sodium hydroxymethanesulfonate (NaHMS), sodium 2-hydroxyethylsulfonate (NaHES), and ammonium 2-hydroxyethylsulfonate (NH4HES) under subsaturated and supersaturated environments. The mass changes in the three hydroxyalkylsulfonates at different relative humidities at 25 °C were examined by a vapor sorption analyzer, and the mass growth factors were measured to be 3.25 ± 0.01 for NaHMS, 3.32 ± 0.02 for NaHES, and 3.34 ± 0.04 for NH4HES at 90% RH. Their hygroscopic growth was investigated by a humidity tandem differential mobility analyzer, and hygroscopic growth factors were 1.78 ± 0.02 for NaHMS, 1.71 ± 0.02 for NaHES, and 1.68 ± 0.03 for NH4HES at 90% RH. Furthermore, the CCN activities of NaHMS, NaHES, and NH4HES were explored, and their single hygroscopicity parameters (κccn) were measured to be 0.649 ± 0.097 for NaHMS, 0.559 ± 0.069 for NaHES, and 0.434 ± 0.073 for NH4HES. In addition, the hygroscopic growth and CCN activities of binary mixtures of ammonium sulfate with one of the three hydroxyalkylsulfonates were also examined.
Collapse
Affiliation(s)
- Chao Peng
- State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Kotiba A Malek
- Department of Chemical and Biomolecular Engineering, A. James Clark School of Engineering, University of Maryland, College Park, MD 20742, USA
| | - Dewansh Rastogi
- Department of Chemical and Biomolecular Engineering, A. James Clark School of Engineering, University of Maryland, College Park, MD 20742, USA
| | - Yuqing Zhang
- State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Weigang Wang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiang Ding
- State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Akua A Asa-Awuku
- Department of Chemical and Biomolecular Engineering, A. James Clark School of Engineering, University of Maryland, College Park, MD 20742, USA; Department of Chemistry and Biochemistry, College of Computer, Mathematical and Natural Sciences, University of Maryland, College Park, MD 20742, USA
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Mingjin Tang
- State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
16
|
Li LF, Chen Z, Liu P, Zhang YH. Direct Measurement of pH Evolution in Aerosol Microdroplets Undergoing Ammonium Depletion: A Surface-Enhanced Raman Spectroscopy Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6274-6281. [PMID: 35476405 DOI: 10.1021/acs.est.1c08626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Accurately measuring the pH of atmospheric aerosols is a prerequisite for understanding the multiphase chemistry that profoundly affects the environment and climate systems. Despite the advancements of experimental techniques for in situ pH measurements in aerosols, current studies are limited to measuring the static pH of aerosol microdroplets with an unperturbed composition. This steady-state scenario, however, deviates from the real-world aerosols undergoing atmospheric aging reactions, specifically, those characterized with a spontaneous displacement of strong bases (or acids) with high volatility. Here, we introduce a continuous and in situ measurement of aerosol pH by using a 4-mercaptopyridine-functionalized silver nanoparticle probe and surface-enhanced Raman spectroscopy. We find that the ammonium depletion─a spontaneous displacement of ammonium by dicarboxylic acid salts─continuously acidifies aerosol water over time. The decaying trends of pH in the aerosols under various humidity conditions can be unified with a universal exponential function. Such an exponentially decaying function further indicates that the ammonium depletion reaction is a self-limiting process. Our technique can be applied to study the dynamic change of aerosol acidity during the complex atmospheric aging processes, toward elucidating their implications on atmospheric chloride, nitrate, and ammonium cycles.
Collapse
Affiliation(s)
- Lin-Fang Li
- Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Zhe Chen
- Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Pai Liu
- Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yun-Hong Zhang
- Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| |
Collapse
|
17
|
Solid organic-coated ammonium sulfate particles at high relative humidity in the summertime Arctic atmosphere. Proc Natl Acad Sci U S A 2022; 119:e2104496119. [PMID: 35344428 PMCID: PMC9168484 DOI: 10.1073/pnas.2104496119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Physical and chemical properties of individual atmospheric particles determine their climate impacts. Hygroscopic inorganic salt particles mixed with trace amounts of organic material are predicted to be liquid under typical tropospheric conditions in the summertime Arctic. Yet, we unexpectedly observed a significant concentration of solid particles composed of ammonium sulfate with an organic coating under conditions of high relative humidity and low temperature. These particle properties are consistent with marine biogenic-derived new particle formation and growth, with particle collision hypothesized to result in the solid phase. This particle source is predicted to have increasing relevance in the context of declining Arctic sea ice and increasing open water, with impacts on clouds, and therefore climate. The ability of atmospheric aerosols to impact climate through water uptake and cloud formation is fundamentally determined by the size, composition, and phase (liquid, semisolid, or solid) of individual particles. Particle phase is dependent on atmospheric conditions (relative humidity and temperature) and chemical composition and, importantly, solid particles can inhibit the uptake of water and other trace gases, even under humid conditions. Particles composed primarily of ammonium sulfate are presumed to be liquid at the relative humidities (67 to 98%) and temperatures (−2 to 4 °C) of the summertime Arctic. Under these atmospheric conditions, we report the observation of solid organic-coated ammonium sulfate particles representing 30% of particles, by number, in a key size range (<0.2 µm) for cloud activation within marine air masses from the Arctic Ocean at Utqiaġvik, AK. The composition and size of the observed particles are consistent with recent Arctic modeling and observational results showing new particle formation and growth from dimethylsulfide oxidation to form sulfuric acid, reaction with ammonia, and condensation of marine biogenic sulfate and highly oxygenated organic molecules. Aqueous sulfate particles typically undergo efflorescence and solidify at relative humidities of less than 34%. Therefore, the observed solid phase is hypothesized to occur from contact efflorescence during collision of a newly formed Aitken mode sulfate particle with an organic-coated ammonium sulfate particle. With declining sea ice in the warming Arctic, this particle source is expected to increase with increasing open water and marine biogenic emissions.
Collapse
|
18
|
Hůnová I, Brabec M, Geletič J, Malý M, Dumitrescu A. Local fresh- and sea-water effects on fog occurrence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150799. [PMID: 34626626 DOI: 10.1016/j.scitotenv.2021.150799] [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: 07/20/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Fog is an important atmospheric phenomenon highly relevant to ecosystems and/or the environment. Two essential prerequisites of fog formation are the presence of fog condensation nuclei and water in the atmosphere. The aim of our study was to examine in detail how fog occurrence is influenced by water areas in the immediate vicinity of the fog observation site. We have used as input data long-term observations on fog occurrence measured at 56 professional meteorological stations in Romania in 1981-2017 and GIS-derived information on water areas and on two topographical indices, TWI and TPI, in the neighbourhood of these stations. We formulated three alternative models of different complexity based on a semiparametric generalised additive logistic model for the probability of fog occurrence with potentially nonlinear, smooth effects modelled via penalised splines. A radius of 9 km appeared to be the most influential when considering the water area in a circle around the fog observation station. Based on our results, we concluded that (i) the water area in the vicinity of the station is a factor influencing fog occurrence, (ii) the water's effect differs according to water type (freshwater or seawater proximity), and (iii) GIS-derived topographical indices are informative for the explanation of fog occurrence and their inclusion enhanced the fit of the models substantially. Our findings, based on a reliable long-term data set of fog occurrence and recent GIS-derived data, explored by a relevant statistical approach will enhance further considerations related to fog formation and its environmental consequences.
Collapse
Affiliation(s)
- Iva Hůnová
- Czech Hydrometeorological Institute, Na Sabatce 17, 143 06 Prague 4 - Komorany, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benatska 2, 128 00 Prague 2, Czech Republic.
| | - Marek Brabec
- Institute of Computer Science of the Czech Academy of Sciences, Pod Vodarenskou vezi 2, 182 07 Prague 8, Czech Republic; National Institute of Public Health, Srobarova 48, 100 42 Prague 10, Czech Republic.
| | - Jan Geletič
- Institute of Computer Science of the Czech Academy of Sciences, Pod Vodarenskou vezi 2, 182 07 Prague 8, Czech Republic.
| | - Marek Malý
- Institute of Computer Science of the Czech Academy of Sciences, Pod Vodarenskou vezi 2, 182 07 Prague 8, Czech Republic; National Institute of Public Health, Srobarova 48, 100 42 Prague 10, Czech Republic.
| | - Alexandru Dumitrescu
- Meteo Romania (National Meteorological Administration), Department of Climatology, 013 686, Bucharest, Romania.
| |
Collapse
|
19
|
Measurements of Static and Dynamic Bubble Surface Tension Using a Deformation-Based Microfluidic Tensiometer. J Phys Chem B 2021; 125:13916-13927. [PMID: 34919401 DOI: 10.1021/acs.jpcb.1c06710] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The surface tension of bubbles is critical for processes involving mixed liquid-gas systems, from sea spray aerosol generation to firefighting foam aspiration. In particular, the size- and surfactant-dependent time scales of dynamic surface tension decay due to adsorption of surface-active chemicals at the curved interface significantly dictate the multiphase system dynamics. While size-dependent surfactant adsorption and interfacial dynamics have been well characterized for liquid-liquid systems using microfluidic platforms, application of microfluidic methods to liquid-gas systems has received less attention. This work uses a high-throughput microfluidic tensiometer to measure the static and dynamic surface tension of microscale bubbles compared with millimeter bubbles characterized by pendant drop. It is shown that the static surface tension measurements for surfactant-free interfaces with microfluidics show good agreement with pendant drop for most systems. At the same time, its accuracy can be affected by bubble pressure, inertia force at high Re, drag force, bubble expansion, and image processing limitation. In the presence of surfactants, the dynamic surface tension measurements show that both smaller bubbles and higher surfactant concentrations can lead to a much shorter time to reach equilibrium compared with pendant drop, similar to the observation for liquid-liquid interfaces. This work shows the potential of a microfluidic tensiometer to capture early time surface tension decay and accurately measure surface tension even in the presence of Marangoni stress tangential to the interface.
Collapse
|
20
|
Li W, Teng X, Chen X, Liu L, Xu L, Zhang J, Wang Y, Zhang Y, Shi Z. Organic Coating Reduces Hygroscopic Growth of Phase-Separated Aerosol Particles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16339-16346. [PMID: 34894668 DOI: 10.1021/acs.est.1c05901] [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] [Indexed: 06/14/2023]
Abstract
A large fraction of secondary aerosol particles are liquid-liquid phase-separated with an organic shell and an inorganic core. This has the potential to regulate the hygroscopicity of such particles, with significant implications for their optical properties, reactivity, and lifetime. However, it is unclear how this phase separation affects the hygroscopic growth of the particles. Here, we showed a large variation in hygroscopic growth (e.g., 1.14-1.32 under a relative humidity (RH) of 90%) of particles from the forest and urban atmosphere, which had different average core-shell ratios. For this reason, a controlled laboratory experiment further quantifies the impact of the organic shell on particle growth with different RH values. Laboratory experiments demonstrated that (NH4)2SO4 particles with thicker secondary organic shells have a lower growth factor at an RH below 94%. Organic shells started to deliquesce first (RH > 50%) and the phase changes of sulfate cores from solid to liquid took place at an RH higher than 80% as deliquescence relative humidity of pure (NH4)2SO4. Our study provides the first direct evidence on an individual particle basis that hygroscopic growth behavior of phase-separated particles is dependent on the thickness of organic shells, highlighting the importance of organic coating in water uptake and possible heterogeneous reactions of the phase-separated particles.
Collapse
Affiliation(s)
- Weijun Li
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Xiaome Teng
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Xiyao Chen
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Lei Liu
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Liang Xu
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Jian Zhang
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Yuanyuan Wang
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Yue Zhang
- Department of Atmospheric Sciences, Texas A&M University, College Station, Texas 77843, United States
| | - Zongbo Shi
- School of Geography, Earth and Environment Sciences, University of Birmingham, Birmingham B15 2TT, U.K
| |
Collapse
|
21
|
A database for deliquescence and efflorescence relative humidities of compounds with atmospheric relevance. FUNDAMENTAL RESEARCH 2021. [DOI: 10.1016/j.fmre.2021.11.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
22
|
Wei J, Fang T, Lakey PSJ, Shiraiwa M. Iron-Facilitated Organic Radical Formation from Secondary Organic Aerosols in Surrogate Lung Fluid. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 56:7234-7243. [PMID: 34596401 DOI: 10.1021/acs.est.1c04334] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Respiratory deposition of secondary organic aerosols (SOA) and iron may lead to the generation of reactive oxygen species and free radicals in lung fluid to cause oxidative stress, but their underlying mechanism and formation kinetics are not well understood. Here we demonstrate substantial formation of organic radicals in surrogate lung fluid (SLF) by mixtures of Fe2+ and SOA generated from photooxidation of isoprene, α-terpineol, and toluene. The molar yields of organic radicals by SOA are measured to be 0.03-0.5% in SLF, which are 5-10 times higher than in water. We observe that Fe2+ enhances organic radical yields dramatically by a factor of 20-80, which can be attributed to Fe2+-facilitated decomposition of organic peroxides, in consistency with a positive correlation between peroxide contents and organic radical yields. Ascorbate mediates redox cycling of iron ions to sustain organic peroxide decomposition, as supported by kinetic modeling reproducing time- and concentration-dependence of organic radical formation as well as additional experiments observing the formation of Fe2+ and ascorbate radicals in mixtures of ascorbate and Fe3+. •OH and superoxide are found to be scavenged by antioxidants efficiently. These findings have implications on the role of organic radicals in oxidative damage and lipid peroxidation.
Collapse
Affiliation(s)
- Jinlai Wei
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Ting Fang
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Pascale S J Lakey
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| |
Collapse
|
23
|
Abstract
Evaluation of the cloud seeding effect is a challenge due to lack of directly physical observational evidence. In this study, an approach for directly observing the cloud seeding effect is proposed using a 1548 nm coherent Doppler wind lidar (CDWL). Normalized skewness was employed to identify the components of the reflectivity spectrum. The spectrum detection capability of a CDWL was verified by a 24.23-GHz Micro Rain Radar (MRR) in Hefei, China (117°15′ E, 31°50′ N), and different types of lidar spectra were detected and separated, including aerosol, turbulence, cloud droplet, and precipitation. Spectrum analysis was applied as a field experiment performed in Inner Mongolia, China (112°39′ E, 42°21′ N ) to support the cloud seeding operation for the 70th anniversary of China’s national day. The CDWL can monitor the cloud motion and provide windshear and turbulence information ensuring operation safety. The cloud-precipitation process is detected by the CDWL, microwave radiometer (MWR) and Advanced Geosynchronous Radiation Imager (AGRI) in FY4A satellites. In particular, the spectrum width and skewness of seeded cloud show a two-layer structure, which reflects cloud component changes, and it is possibly related to cloud seeding effects. Multi-component spectra are separated into four clusters, which are well distinguished by spectrum width and vertical velocity. In general, our findings provide new evidence that the reflectivity spectrum of CDWL has potential for assessing cloud seeding effects.
Collapse
|
24
|
Ma S, Pang S, Li J, Zhang Y. A review of efflorescence kinetics studies on atmospherically relevant particles. CHEMOSPHERE 2021; 277:130320. [PMID: 33773310 DOI: 10.1016/j.chemosphere.2021.130320] [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: 01/14/2021] [Revised: 03/11/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
The efflorescence transitions of aerosol particles have been intensively investigated due to their critical impacts on global climate and atmospheric chemistry. In the present study, we present a critical review of efflorescence kinetics focusing on three key issues: the efflorescence relative humidity (ERH) and the influence factors for aerosol ERH (e.g. particle sizes, and temperature); efflorescence processes of mixed aerosols, concerning the effect of coexisting inorganic and organic components on the efflorescence of inorganic salts; homogeneous and heterogeneous nucleation rates of pure and mixed aerosols. Among the previous studies, there are significant discrepancies for measured aerosol ERH under even the same conditions. Moreover, the interactions between organic and inorganic components remain largely unclear, causing efflorescence transition behaviours and chemical composition evolutions of certain mixed systems to be debatable. Thus, it is important to better understand efflorescence to gain insights into the physicochemical properties and characterize observed efflorescence characteristics of atmospheric particles, as well as guide further studies on aerosol hygroscopicity and reactivity.
Collapse
Affiliation(s)
- Shuaishuai Ma
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Shufeng Pang
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Jing Li
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
| | - Yunhong Zhang
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
| |
Collapse
|
25
|
Ge M, Tong S, Wang W, Zhang W, Chen M, Peng C, Li J, Zhou L, Chen Y, Liu M. Important Oxidants and Their Impact on the Environmental Effects of Aerosols. J Phys Chem A 2021; 125:3813-3825. [PMID: 33687210 DOI: 10.1021/acs.jpca.0c10236] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxidants are central species in the atmosphere, where they not only determine secondary particle formation but also impact human health and climate change. In general, they are unstable, highly reactive, and recyclable and have been studied in field observations, laboratory studies, and model simulations. The most widely investigated oxidants, such as OH radicals, O3, and Cl atom, HONO, NO3, N2O5, and Criegee Intermediates (CIs) have attracted more attention recently. Furthermore, secondary particles formed in the oxidations processes impact the particle physicochemical properties, such as hygroscopicity and optical properties and therefore impact the atmospheric radiation balance. Therefore, the newest investigation results of important oxidants (HONO, NO3, N2O5, and CIs) are reviewed in this manuscript, and the environmental effects of secondary particles formed through corresponding oxidation processes are also stated. Furthermore, some perspectives are further discussed in the article.
Collapse
Affiliation(s)
- Maofa Ge
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shengrui Tong
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Weigang Wang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Wenqian Zhang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Meifang Chen
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,College of Chemistry and Material Science, Anhui Normal University, Wuhu 241000, P. R. China
| | - Chao Peng
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Junling Li
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Li Zhou
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,College of Architecture and Environment, Sichuan University, Chengdu 610065, P. R. China
| | - Yi Chen
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, P. R. China
| | - Mingyuan Liu
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| |
Collapse
|
26
|
Farmer DK, Boedicker EK, DeBolt HM. Dry Deposition of Atmospheric Aerosols: Approaches, Observations, and Mechanisms. Annu Rev Phys Chem 2021; 72:375-397. [PMID: 33472381 DOI: 10.1146/annurev-physchem-090519-034936] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Aerosols are liquid or solid particles suspended in the atmosphere, typically with diameters on the order of nanometers to microns. These particles impact air quality and the radiative balance of the planet. Dry deposition is a key process for the removal of aerosols from the atmosphere and plays an important role in controlling the lifetime of atmospheric aerosols. Dry deposition is driven by turbulence and shows a strong dependence on particle size. This review summarizes the mechanisms behind aerosol dry deposition, including measurement approaches, field observations, and modeling studies. We identify several gaps in the literature, including deposition over the cryosphere (i.e., snow and ice surfaces) and the ocean; in addition, we highlight new techniques to measure black carbon fluxes. While recent advances in aerosol instrumentation have enhanced our understanding of aerosol sources and chemistry, dry deposition and other loss processes remain poorly investigated.
Collapse
Affiliation(s)
- Delphine K Farmer
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA;
| | - Erin K Boedicker
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA;
| | - Holly M DeBolt
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA;
| |
Collapse
|
27
|
R L, B S M, B S S, Bhanage V, Rathod A, Tiwari A, Beig G, Singh S. Propagation of cloud base to higher levels during Covid-19-Lockdown. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 759:144299. [PMID: 33341515 PMCID: PMC9757895 DOI: 10.1016/j.scitotenv.2020.144299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 06/12/2023]
Abstract
Aerosol-cloud interactions and feedbacks play an important role in modulating cloud development, microphysical and optical properties thus enhancing or reducing precipitation over polluted/pristine regions. The lockdown enforced on account of Covid-19 pandemic is a unique opportunity to verify the influence of drastic reduction in aerosols on cloud development and its vertical distribution embedded in identical synoptic conditions. Cloud bases measured by ceilometer in Delhi, the capital of India, are observed to propagate from low level to higher levels as the lockdown progresses. It is explained in terms of trends in temporal variation of cloud condensation nuclei (CCN) and precursor gases to secondary hygroscopic aerosols. The large reduction (47%) in CCN estimated from aerosol extinction coefficient during the lockdown results in upward shift of cloud bases. Low clouds with bases located below 3 km are found to have reduced significantly from 63% (of total clouds distributed in the vertical) during pre-lockdown to 12% in lockdown period (less polluted). Cloud base height is found to have an inverse correlation with CCN (r = -0.64) and NO2/NH3 concentrations (r = -0.7). The role of meteorology and CCN in modulating the cloud vertical profiles is discussed in terms of anomalies of various controlling factors like lifting condensation level (LCL), precipitable water content (PWC) and mixing layer height (MLH).
Collapse
Affiliation(s)
- Latha R
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | - Murthy B S
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India.
| | - Sandeepan B S
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | | | - Aditi Rathod
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | - Arpit Tiwari
- India Meteorological Department, Ministry of Earth Sciences, New Delhi, India
| | - Gufran Beig
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | - Siddhartha Singh
- India Meteorological Department, Ministry of Earth Sciences, New Delhi, India
| |
Collapse
|
28
|
Wei J, Fang T, Wong C, Lakey PSJ, Nizkorodov SA, Shiraiwa M. Superoxide Formation from Aqueous Reactions of Biogenic Secondary Organic Aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:260-270. [PMID: 33352036 DOI: 10.1021/acs.est.0c07789] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Reactive oxygen species (ROS) play a central role in aqueous-phase processing and health effects of atmospheric aerosols. Although hydroxyl radical (•OH) and hydrogen peroxide (H2O2) are regarded as major oxidants associated with secondary organic aerosols (SOA), the kinetics and reaction mechanisms of superoxide (O2•-) formation are rarely quantified and poorly understood. Here, we demonstrate a dominant formation of O2•- with molar yields of 0.01-0.03% from aqueous reactions of biogenic SOA generated by •OH photooxidation of isoprene, β-pinene, α-terpineol, and d-limonene. The temporal evolution of •OH and O2•- formation is elucidated by kinetic modeling with a cascade of aqueous reactions including the decomposition of organic hydroperoxides, •OH oxidation of primary or secondary alcohols, and unimolecular decomposition of α-hydroxyperoxyl radicals. Relative yields of various types of ROS reflect a relative abundance of organic hydroperoxides and alcohols contained in SOA. These findings and mechanistic understanding have important implications on the atmospheric fate of SOA and particle-phase reactions of highly oxygenated organic molecules as well as oxidative stress upon respiratory deposition.
Collapse
Affiliation(s)
- Jinlai Wei
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Ting Fang
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Cynthia Wong
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Pascale S J Lakey
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Sergey A Nizkorodov
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| |
Collapse
|
29
|
Huang Q, Wei H, Marr LC, Vikesland PJ. Direct Quantification of the Effect of Ammonium on Aerosol Droplet pH. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:778-787. [PMID: 33296596 DOI: 10.1021/acs.est.0c07394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ammonium is an important atmospheric constituent that dictates many environmental processes. The impact of the ammonium ion concentration on 10-50 μm aerosol droplet pH was quantified using pH nanoprobes and surface-enhanced Raman spectroscopy (SERS). Sample solutions were prepared by mixing 1 M ammonium sulfate (AS), ammonium nitrate (AN), sodium sulfate (SS), or sodium nitrate (SN) solutions with 1 M phosphate buffer (PB) at different volume ratios. Stable pH values were measured for pure PB, AS, and AN droplets at different concentrations. The centroid pH of 1 M PB droplets was ∼11, but when PB was systematically replaced with ammonium (AS- or AN-PB), the centroid pH within the droplets decreased from ≈11 to 5.5. Such a decrease was not observed in sodium (SS- or SN-PB) droplets, and no pH differences were observed between sulfate and nitrate salts. Ammonia partitioning to the gas phase in ammonium-containing droplets was evaluated to be negligible. Raman sulfate peak (∼980 cm-1) intensity measurements and surface tension measurements were conducted to investigate changes in ion distribution. The pH difference between ammonium-containing droplets and ammonium-free droplets is attributed to the alteration of the ion distribution in the presence of ammonium.
Collapse
Affiliation(s)
- Qishen Huang
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
- Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center, Blacksburg, Virginia 24061, United States
| | - Haoran Wei
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Linsey C Marr
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
- Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center, Blacksburg, Virginia 24061, United States
| | - Peter J Vikesland
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
- Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center, Blacksburg, Virginia 24061, United States
| |
Collapse
|
30
|
Al-Abadleh HA, Rana MS, Mohammed W, Guzman MI. Dark Iron-Catalyzed Reactions in Acidic and Viscous Aerosol Systems Efficiently Form Secondary Brown Carbon. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:209-219. [PMID: 33290060 DOI: 10.1021/acs.est.0c05678] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Iron-driven secondary brown carbon formation reactions from water-soluble organics in cloud droplets and aerosols create insoluble and soluble products of emerging atmospheric importance. This work shows, for the first time, results on dark iron-catalyzed polymerization of catechol forming insoluble black polycatechol particles and colored water-soluble oligomers under conditions characteristic of viscous multicomponent aerosol systems with relatively high ionic strength (I = 1-12 m) and acidic pH (∼2). These systems contain ammonium sulfate (AS)/nitrate (AN) and C3-C5 dicarboxylic acids, namely, malonic, malic, succinic, and glutaric acids. Using dynamic light scattering (DLS) and ultra high pressure liquid chromatography-mass spectrometry (UHPLC-MS), we show results on the rate of particle growth/agglomeration and identity of soluble oligomeric reaction products. We found that increasing I above 1 m and adding diacids with oxygen-to-carbon molar ratio (O:C > 1) significantly reduced the rate of polycatechol formation/aggregation by a factor of 1.3 ± 0.4 in AS solution in the first 60 min of reaction time. Using AN, rates were too slow to be quantified using DLS, but particles formed after 24 h reaction time. These results were explained by the relative concentration and affinity of ligands to Fe(III). We also report detectable amounts of soluble and colored oligomers in reactions with a slow rate of polycatechol formation, including organonitrogen compounds. These results highlight that brown carbon formation from iron chemistry is efficient under a wide range of aerosol physical states and chemical composition.
Collapse
Affiliation(s)
- Hind A Al-Abadleh
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada
| | - Md Sohel Rana
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Wisam Mohammed
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada
| | - Marcelo I Guzman
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| |
Collapse
|
31
|
Luo M, Wauer NA, Angle KJ, Dommer AC, Song M, Nowak CM, Amaro RE, Grassian VH. Insights into the behavior of nonanoic acid and its conjugate base at the air/water interface through a combined experimental and theoretical approach. Chem Sci 2020; 11:10647-10656. [PMID: 33144932 PMCID: PMC7583472 DOI: 10.1039/d0sc02354j] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/15/2020] [Indexed: 12/14/2022] Open
Abstract
The partitioning of medium-chain fatty acid surfactants such as nonanoic acid (NA) between the bulk phase and the air/water interface is of interest to a number of fields including marine and atmospheric chemistry. However, questions remain about the behavior of these molecules, the contributions of various relevant chemical equilibria, and the impact of pH, salt and bulk surfactant concentrations. In this study, the surface adsorption of nonanoic acid and its conjugate base is quantitatively investigated at various pH values, surfactant concentrations and the presence of salts. Surface concentrations of protonated and deprotonated species are dictated by surface-bulk equilibria which can be calculated from thermodynamic considerations. Notably we conclude that the surface dissociation constant of soluble surfactants cannot be directly obtained from these experimental measurements, however, we show that molecular dynamics (MD) simulation methods, such as free energy perturbation (FEP), can be used to calculate the surface acid dissociation constant relative to that in the bulk. These simulations show that nonanoic acid is less acidic at the surface compared to in the bulk solution with a pK a shift of 1.1 ± 0.6, yielding a predicted surface pK a of 5.9 ± 0.6. A thermodynamic cycle for nonanoic acid and its conjugate base between the air/water interface and the bulk phase can therefore be established. Furthermore, the effect of salts, namely NaCl, on the surface activity of protonated and deprotonated forms of nonanoic acid is also examined. Interestingly, salts cause both a decrease in the bulk pK a of nonanoic acid and a stabilization of both the protonated and deprotonated forms at the surface. Overall, these results suggest that the deprotonated medium-chain fatty acids under ocean conditions can also be present within the sea surface microlayer (SSML) present at the ocean/atmosphere interface due to the stabilization effect of the salts in the ocean. This allows the transfer of these species into sea spray aerosols (SSAs). More generally, we present a framework with which the behavior of partially soluble species at the air/water interface can be predicted from surface adsorption models and the surface pK a can be predicted from MD simulations.
Collapse
Affiliation(s)
- Man Luo
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
| | - Nicholas A Wauer
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
| | - Kyle J Angle
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
| | - Abigail C Dommer
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
| | - Meishi Song
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
| | - Christopher M Nowak
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
| | - Rommie E Amaro
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA . ;
- Department of Nanoengineering , Scripps Institution of Oceanography , University of California , La Jolla , San Diego , CA 92093 , USA
| |
Collapse
|
32
|
Rokoni A, Sun Y. Probing the temperature profile across a liquid-vapor interface upon phase change. J Chem Phys 2020; 153:144706. [PMID: 33086805 DOI: 10.1063/5.0024722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Understanding the temperature profile across a liquid-vapor interface in the presence of phase change is essential for the accurate prediction of evaporation, boiling, and condensation. It has been shown experimentally, from non-equilibrium thermodynamics and using molecular dynamics simulations, the existence of an inverted temperature profile across an evaporating liquid-vapor interface, where the vapor-side interface temperature observes the lowest value and the vapor temperature increases away from the interface, opposite to the direction of heat flow. It is worth noting, however, that an inverted temperature profile is not always the case from other experiments and simulations. In this study, we apply non-equilibrium molecular dynamics simulations to systematically study the temperature profile across a liquid-vapor interface during phase change under various heat fluxes in a two-interface setting consisting of both an evaporating and a condensing interface. The calculated vapor temperature shows different characteristics inside the Knudsen layer and in the bulk vapor. In addition, both the direction and magnitude of the vapor temperature gradient, as well as the temperature jump at the liquid-vapor interface, are functions of the applied heat flux. The interfacial entropy generation rate calculated from the vibrational density of state of the interfacial liquid and vapor molecules shows a positive production during evaporation, and the results qualitatively agree with the predictions from non-equilibrium thermodynamics.
Collapse
Affiliation(s)
- Arif Rokoni
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Ying Sun
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, Pennsylvania 19104, USA
| |
Collapse
|
33
|
Abstract
Dry deposition is a key sink of atmospheric particles, which impact human and ecosystem health, and the radiative balance of the planet. However, the deposition parameterizations used in climate and air-quality models are poorly constrained by observations. Dry deposition of submicron particles is the largest uncertainty in aerosol indirect radiative forcing. Our particle flux observations indicate that dry deposition velocities are an order of magnitude lower than models suggest. Our updated, observation-driven parameterizations should reduce uncertainty in modeled dry deposition. The scheme increases modeled accumulation mode aerosol number concentrations, and enhances the combined natural and anthropogenic aerosol indirect effect by −0.63 W m−2, similar in magnitude to the total aerosol indirect forcing in the Intergovernmental Panel on Climate Change report. Wet and dry deposition remove aerosols from the atmosphere, and these processes control aerosol lifetime and thus impact climate and air quality. Dry deposition is a significant source of aerosol uncertainty in global chemical transport and climate models. Dry deposition parameterizations in most global models were developed when few particle deposition measurements were available. However, new measurement techniques have enabled more size-resolved particle flux observations. We combined literature measurements with data that we collected over a grassland in Oklahoma and a pine forest in Colorado to develop a dry deposition parameterization. We find that relative to observations, previous parameterizations overestimated deposition of the accumulation and Aitken mode particles, and underestimated in the coarse mode. These systematic differences in observed and modeled accumulation mode particle deposition velocities are as large as an order of magnitude over terrestrial ecosystems. As accumulation mode particles form most of the cloud condensation nuclei (CCN) that influence the indirect radiative effect, this model-measurement discrepancy in dry deposition alters modeled CCN and radiative forcing. We present a revised observationally driven parameterization for regional and global aerosol models. Using this revised dry deposition scheme in the Goddard Earth Observing System (GEOS)-Chem chemical transport model, we find that global surface accumulation-mode number concentrations increase by 62% and enhance the global combined anthropogenic and natural aerosol indirect effect by −0.63 W m−2. Our observationally constrained approach should reduce the uncertainty of particle dry deposition in global chemical transport models.
Collapse
|
34
|
Ault AP. Aerosol Acidity: Novel Measurements and Implications for Atmospheric Chemistry. Acc Chem Res 2020; 53:1703-1714. [PMID: 32786333 DOI: 10.1021/acs.accounts.0c00303] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The pH of a solution is one of its most fundamental chemical properties, impacting reaction pathways and kinetics across every area of chemistry. The atmosphere is no different, with the pH of the condensed phase driving key chemical reactions that ultimately impact global climate in numerous ways. The condensed phase in the atmosphere is comprised of suspended liquid or solid particles, known as the atmospheric aerosol, which are differentiated from cloud droplets by their much smaller size (primarily <10 μm). The pH of the atmospheric aerosol can enhance certain chemical reactions leading to the formation of additional condensed phase mass from lower volatility species (secondary aerosol), alter the optical and water uptake properties of particles, and solubilize metals that can act as key nutrients in nutrient-limited ecosystems or cause oxidative stress after inhalation. However, despite the importance of aerosol acidity for climate and health, our fundamental understanding of pH has been limited due to aerosol size (by number >99% of particles are <1 μm) and complexity. Within a single atmospheric particle, there can be hundreds to thousands of distinct chemical species, varying water content, high ionic strengths, and different phases (liquid, semisolid, and solid). Making aerosol analysis even more challenging, atmospheric particles are constantly evolving through heterogeneous reactions with gases and multiphase chemistry within the condensed phase. Based on these challenges, traditional pH measurements are not feasible, and, for years, indirect and proxy methods were the most common way to estimate aerosol pH, with mixed results. However, aerosol pH needs to be incorporated into climate models to accurately determine which chemical reactions are dominant in the atmosphere. Consequently, experimental measurements that probe pH in atmospherically relevant particles are sorely needed to advance our understanding of aerosol acidity.This Account describes recent advances in measurements of aerosol particle acidity, specifically three distinct methods we developed for experimentally determining particle pH. Our acid-conjugate base method uses Raman microspectroscopy to probe an acid (e.g., HSO4-) and its conjugate base (e.g., SO42-) in individual micrometer-sized particles. Our second approach is a field-deployable colorimetric method based on pH indicators (e.g., thymol blue) and cell phone imaging to provide a simple, low-cost approach to ensemble average (or bulk) pH for particles in distinct size ranges down to a few hundred nanometers in diameter. In our third method, we monitor acid-catalyzed polymer degradation of a thin film (∼23 nm) of poly(ε-caprolactone) (PCL) on silicon by individual particles with atomic force microscopy (AFM) after inertially impacting particles of different pH. These measurements are improving our understanding of aerosol pH from a fundamental physical chemistry perspective and have led to initial atmospheric measurements. The impact of aerosol pH on key atmospheric processes, such as secondary organic aerosol (SOA) formation, is discussed. Some unique findings, such as an unexpected size dependence to aerosol pH and kinetic limitations, illustrate that particles are not always in thermodynamic equilibrium with the surrounding gas. The implications of our limited, but improving, understanding of the fundamental chemical concept of pH in the atmospheric aerosol are critical for connecting chemistry and climate.
Collapse
Affiliation(s)
- Andrew P. Ault
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
35
|
Farmer DK, Riches M. Measuring Biosphere-Atmosphere Exchange of Short-Lived Climate Forcers and Their Precursors. Acc Chem Res 2020; 53:1427-1435. [PMID: 32687308 DOI: 10.1021/acs.accounts.0c00203] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Exchange of reactive trace gases over the biosphere is a key source of reactive organic carbon to the atmosphere and thus influences the formation of both ozone (O3) and secondary organic aerosol (SOA). Both O3 and aerosol particles are short-lived climate forcers and impact the radiative balance of the planet, and their sources and sinks are chemically complex. However, the biosphere also acts as a deposition sink for organic and inorganic compounds, including O3, aerosols, and their precursors. Wet and dry deposition provides a key lever on the lifetime of trace gases and particles in the atmosphere and thus on their potential to influence the radiative balance of the planet. The fluxes of reactive trace gases and particles are part of an atmospheric biogeochemical cycle that includes feedbacks through drought and other climate components.Recent advances in measurement techniques have enabled new field observations of trace gas and particle fluxes. Our method development has focused on the leaf, branch, and forest level, although satellite measurements coupled to modeling also provide promising new approaches to constraining trace gas fluxes. Leaf chamber measurements of volatile organic compound (VOC) emissions highlight leaf-to-leaf and plant-to-plant variability in both photosynthesis and emissions of individual VOCs, in addition to differences in emissions across different isomers of monoterpenes. Isomers obviously have different chemical properties (e.g., reaction rates with OH radicals, SOA yield) and thus hold different potentials as precursors for short-lived climate forcers.The biosphere acts as both sources and sinks of the oxidation products of monoterpenes and other biogenic VOCs. Developments in chemical ionization mass spectrometry have recently enabled measurements of volatile organic acids, which demonstrate a strong temperature-dependent ecosystem source, as well as a source from in-canopy chemistry. In-canopy chemistry also influences particle fluxes, although deposition should dominate their net exchange. Our field observations of chemically resolved particle fluxes demonstrate the simultaneous, competing processes driving forest exchange. To separate out these competing processes, we use black carbon as an inert tracer for particle deposition. Our recent measurements demonstrate the importance of wet deposition in controlling particle lifetime in the atmosphere. Overall, new measurement techniques have enabled both field and laboratory observations to improve our understanding of biosphere-atmosphere interactions and their influence on climate processes.
Collapse
Affiliation(s)
- Delphine K. Farmer
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Mj Riches
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| |
Collapse
|
36
|
Luo M, Shemesh D, Sullivan MN, Alves MR, Song M, Gerber RB, Grassian VH. Impact of pH and NaCl and CaCl2 Salts on the Speciation and Photochemistry of Pyruvic Acid in the Aqueous Phase. J Phys Chem A 2020; 124:5071-5080. [DOI: 10.1021/acs.jpca.0c01016] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Man Luo
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - Dorit Shemesh
- Institute of Chemistry and Fritz Haber Research Center, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Michael N. Sullivan
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - Michael R. Alves
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - Meishi Song
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - R. Benny Gerber
- Institute of Chemistry and Fritz Haber Research Center, Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Department of Chemistry, University of California, Irvine, California 92617, United States
| | - Vicki H. Grassian
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
- Scripps Institution of Oceanography, University of California, San Diego, California 92037, United States
| |
Collapse
|
37
|
Adsorption Capacities of Hygroscopic Materials Based on NaCl-TiO 2 and NaCl-SiO 2 Core/Shell Particles. JOURNAL OF NANOTECHNOLOGY 2020. [DOI: 10.1155/2020/3683629] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hygroscopic materials which possess high moisture adsorption capacity were successfully upgraded by the functionalization of sodium chloride (NaCl) using two nuances of oxides. A procedure was developed to first prepare submicron-sized NaCl crystals; thereafter, these crystals were coated by choice of either titanium dioxide (TiO2) or silica (SiO2) to enhance the hygroscopic properties of NaCl and prevent its premature deliquescence. After coating, several analytical techniques were employed to evaluate the obtained composite materials. Our findings revealed that both composites NaCl-TiO2 and NaCl-SiO2 gave excellent performances by exhibiting interesting hydrophilic properties, compared to the sole NaCl. This was demonstrated by both environmental scanning electron microscope (ESEM) and water vapor adsorption experiments. In particular, NaCl-TiO2 composite showed the highest water adsorption capacity at low relative humidity and at a faster adsorption rate, induced by the high surface energy owing to the presence of TiO2. This result was also confirmed by the kinetics of adsorption, which revealed that not only does NaCl-TiO2 adsorb more water vapor than NaCl-SiO2 or sole NaCl but also the adsorption occurred at a much higher rate. While at room temperature and high relative humidity, the NaCl-SiO2 composite showed the best adsorption properties making it ideal to be used as a hygroscopic material, showing maximum adsorption performance compared to NaCl-TiO2 or sole NaCl. Therefore, NaCl-TiO2 and NaCl-SiO2 composites could be considered as promising hygroscopic materials and potential candidates to replace the existing salt seeding agents.
Collapse
|
38
|
Multi-Evidence and Multi-Modal Fusion Network for Ground-Based Cloud Recognition. REMOTE SENSING 2020. [DOI: 10.3390/rs12030464] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In recent times, deep neural networks have drawn much attention in ground-based cloud recognition. Yet such kind of approaches simply center upon learning global features from visual information, which causes incomplete representations for ground-based clouds. In this paper, we propose a novel method named multi-evidence and multi-modal fusion network (MMFN) for ground-based cloud recognition, which could learn extended cloud information by fusing heterogeneous features in a unified framework. Namely, MMFN exploits multiple pieces of evidence, i.e., global and local visual features, from ground-based cloud images using the main network and the attentive network. In the attentive network, local visual features are extracted from attentive maps which are obtained by refining salient patterns from convolutional activation maps. Meanwhile, the multi-modal network in MMFN learns multi-modal features for ground-based cloud. To fully fuse the multi-modal and multi-evidence visual features, we design two fusion layers in MMFN to incorporate multi-modal features with global and local visual features, respectively. Furthermore, we release the first multi-modal ground-based cloud dataset named MGCD which not only contains the ground-based cloud images but also contains the multi-modal information corresponding to each cloud image. The MMFN is evaluated on MGCD and achieves a classification accuracy of 88.63% comparative to the state-of-the-art methods, which validates its effectiveness for ground-based cloud recognition.
Collapse
|
39
|
Tahir MA, Zhang X, Cheng H, Xu D, Feng Y, Sui G, Fu H, Valev VK, Zhang L, Chen J. Klarite as a label-free SERS-based assay: a promising approach for atmospheric bioaerosol detection. Analyst 2020; 145:277-285. [DOI: 10.1039/c9an01715a] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We present a SERS-based Klarite interface for the rapid and culture-free detection and quantification of atmospheric bioaerosols in the real-world environment.
Collapse
|
40
|
Yang P, Yang H, Wang N, Du C, Pang S, Zhang Y. Hygroscopicity measurement of sodium carbonate, β-alanine and internally mixed β-alanine/Na 2CO 3 particles by ATR-FTIR. J Environ Sci (China) 2020; 87:250-259. [PMID: 31791498 DOI: 10.1016/j.jes.2019.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/27/2019] [Accepted: 07/02/2019] [Indexed: 05/16/2023]
Abstract
Water-uptakes of pure sodium carbonate (Na2CO3), pure β-alanine and internally mixed β-alanine/Na2CO3 aerosol particles with different mole ratios are first monitored using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) technique. For pure Na2CO3 aerosol particles, combining the absorptions at 877 and 1422 cm-1 with abrupt water loss shows the efflorescence relative humidity (ERH) of 62.9%-51.9%. Upon humidifying, solid Na2CO3 firstly absorbs water to from Na2CO3·H2O crystal at 72.0% RH and then deliquesces at 84.5% RH (DRH). As for pure β-alanine particles, the crystallization takes place in the range of 42.4%-33.2% RH and becomes droplets at ~88.2% RH. When β-alanine is mixed with Na2CO3 at various mole ratios, it shows no efflorescence of Na2CO3 when β-alanine to Na2CO3 mole ratio (OIR) is 2:1. For 1:1 and 1:2 β-alanine/Na2CO3 aerosols, the ERHs of Na2CO3 are 51.8%-42.3% and 57.1%-42.3%, respectively. While β-alanine crystal appears from 62.7% RH for 2:1 and 59.4% RH for both 1:1 and 1:2 particles and lasts to driest state. On hydration, the DRH is 44.7%-75.2% for Na2CO3 with the OIR of 1:1 and 44.7%-69.0% for 1:2 mixture, and those of β-alanine are 74.8% for 2:1 mixture and 68.9% for two others. After the first dehumidification-humidification, all the water contents decrease despite of constituent fraction. And at ~92% RH, the remaining water contents are 92%, 89% and 82% at ~92% RH, corresponding to OIR of 2:1, 1:1 and 1:2 mixed system, respectively.
Collapse
Affiliation(s)
- Ping Yang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Hui Yang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Na Wang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Chunyun Du
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Shufeng Pang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
| | - Yunhong Zhang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| |
Collapse
|
41
|
Gérard V, Noziere B, Fine L, Ferronato C, Singh DK, Frossard AA, Cohen RC, Asmi E, Lihavainen H, Kivekäs N, Aurela M, Brus D, Frka S, Cvitešić Kušan A. Concentrations and Adsorption Isotherms for Amphiphilic Surfactants in PM 1 Aerosols from Different Regions of Europe. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:12379-12388. [PMID: 31553874 DOI: 10.1021/acs.est.9b03386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Predicting the activation of submicrometer particles into cloud droplets in the atmosphere remains a challenge. The importance of surface tension, σ (mN m-1), in these processes has been evidenced by several works, but information on the "surfactants" lowering σ in actual atmospheric particles remains scarce. In this work, PM1 aerosols from urban, coastal, and remote regions of Europe (Lyon, France, Rogoznica, Croatia, and Pallas, Finland, respectively) were investigated and found to contain amphiphilic surfactants in concentrations up to 2.8 μg m-3 in the air and 1.3 M in the particle dry volume. In Pallas, correlations with the PM1 chemical composition showed that amphiphilic surfactants were present in the entire range of particle sizes, supporting recent works. This implied that they were present in hundreds to thousands of particles cm-3 and not only in a few large particles, as it has been hypothesized. Their adsorption isotherms and critical micelle concentration (CMC) were also determined. The low CMC obtained (3 × 10-5-9 × 10-3 M) implies that surface tension depression should be significant for all the particles containing these compounds, even at activation (growth factor ∼ 10). Amphiphilic surfactants are thus likely to enhance the CCN ability of submicrometer atmospheric particles.
Collapse
Affiliation(s)
- Violaine Gérard
- Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), CNRS , Université Lyon 1 , 69626 Villeurbanne , France
| | - Barbara Noziere
- Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), CNRS , Université Lyon 1 , 69626 Villeurbanne , France
| | - Ludovic Fine
- Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), CNRS , Université Lyon 1 , 69626 Villeurbanne , France
| | - Corinne Ferronato
- Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), CNRS , Université Lyon 1 , 69626 Villeurbanne , France
| | - Dharmendra Kumar Singh
- Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), CNRS , Université Lyon 1 , 69626 Villeurbanne , France
| | - Amanda A Frossard
- Department of Chemistry , University of California, Berkeley , Berkeley , California 94720 , United States
| | - Ronald C Cohen
- Department of Chemistry , University of California, Berkeley , Berkeley , California 94720 , United States
| | - Eija Asmi
- Atmospheric Composition Research , Finnish Meteorological Institute , 00101 Helsinki , Finland
| | - Heikki Lihavainen
- Atmospheric Composition Research , Finnish Meteorological Institute , 00101 Helsinki , Finland
- Svalbard Integrated Arctic Earth Observing System , 9171 Longyearbyen , Norway
| | - Niku Kivekäs
- Atmospheric Composition Research , Finnish Meteorological Institute , 00101 Helsinki , Finland
| | - Minna Aurela
- Atmospheric Composition Research , Finnish Meteorological Institute , 00101 Helsinki , Finland
| | - David Brus
- Atmospheric Composition Research , Finnish Meteorological Institute , 00101 Helsinki , Finland
| | - Sanja Frka
- Division for Marine and Environmental Research , Ruđer Bošković Institute , Zagreb 10000 , Croatia
| | - Ana Cvitešić Kušan
- Division for Marine and Environmental Research , Ruđer Bošković Institute , Zagreb 10000 , Croatia
| |
Collapse
|
42
|
Alpert PA, Corral Arroyo P, Dou J, Krieger UK, Steimer SS, Förster JD, Ditas F, Pöhlker C, Rossignol S, Passananti M, Perrier S, George C, Shiraiwa M, Berkemeier T, Watts B, Ammann M. Visualizing reaction and diffusion in xanthan gum aerosol particles exposed to ozone. Phys Chem Chem Phys 2019; 21:20613-20627. [PMID: 31528972 DOI: 10.1039/c9cp03731d] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atmospheric aerosol particles with a high viscosity may become inhomogeneously mixed during chemical processing. Models have predicted gradients in condensed phase reactant concentration throughout particles as the result of diffusion and chemical reaction limitations, termed chemical gradients. However, these have never been directly observed for atmospherically relevant particle diameters. We investigated the reaction between ozone and aerosol particles composed of xanthan gum and FeCl2 and observed the in situ chemical reaction that oxidized Fe2+ to Fe3+ using X-ray spectromicroscopy. Iron oxidation state of particles as small as 0.2 μm in diameter were imaged over time with a spatial resolution of tens of nanometers. We found that the loss off Fe2+ accelerated with increasing ozone concentration and relative humidity, RH. Concentric 2-D column integrated profiles of the Fe2+ fraction, α, out of the total iron were derived and demonstrated that particle surfaces became oxidized while particle cores remained unreacted at RH = 0-20%. At higher RH, chemical gradients evolved over time, extended deeper from the particle surface, and Fe2+ became more homogeneously distributed. We used the kinetic multi-layer model for aerosol surface and bulk chemistry (KM-SUB) to simulate ozone reaction constrained with our observations and inferred key parameters as a function of RH including Henry's Law constant for ozone, HO3, and diffusion coefficients for ozone and iron, DO3 and DFe, respectively. We found that HO3 is higher in our xanthan gum/FeCl2 particles than for water and increases when RH decreased from about 80% to dry conditions. This coincided with a decrease in both DO3 and DFe. In order to reproduce observed chemical gradients, our model predicted that ozone could not be present further than a few nanometers from a particle surface indicating near surface reactions were driving changes in iron oxidation state. However, the observed chemical gradients in α observed over hundreds of nanometers must have been the result of iron transport from the particle interior to the surface where ozone oxidation occurred. In the context of our results, we examine the applicability of the reacto-diffusive framework and discuss diffusion limitations for other reactive gas-aerosol systems of atmospheric importance.
Collapse
Affiliation(s)
- Peter A Alpert
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
| | - Pablo Corral Arroyo
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland. and Institute for Physical Chemistry, ETH Zürich, 8092 Zürich, Switzerland
| | - Jing Dou
- Institute for Atmospheric and Climate Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Ulrich K Krieger
- Institute for Atmospheric and Climate Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Sarah S Steimer
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Jan-David Förster
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Florian Ditas
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Christopher Pöhlker
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Stéphanie Rossignol
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, F-69626, Villeurbanne, France and Aix Marseille Université, CNRS, LCE UMR 7376, 13331 Marseille, France
| | - Monica Passananti
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, F-69626, Villeurbanne, France and Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, 00710, Helsinki, Finland and Dipartimento di Chimica, Università di Torino, Via Giuria 5, 10125 Torino, Italy
| | - Sebastien Perrier
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, F-69626, Villeurbanne, France
| | - Christian George
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, F-69626, Villeurbanne, France
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
| | - Thomas Berkemeier
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany and School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Benjamin Watts
- Laboratory for Synchrotron Radiation-Condensed Matter, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Markus Ammann
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
| |
Collapse
|
43
|
Jacobs MI, Xu B, Kostko O, Wiegel AA, Houle FA, Ahmed M, Wilson KR. Using Nanoparticle X-ray Spectroscopy to Probe the Formation of Reactive Chemical Gradients in Diffusion-Limited Aerosols. J Phys Chem A 2019; 123:6034-6044. [DOI: 10.1021/acs.jpca.9b04507] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Michael I. Jacobs
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Bo Xu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Oleg Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Aaron A. Wiegel
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Frances A. Houle
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Kevin R. Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| |
Collapse
|
44
|
Al Nimer A, Rocha L, Rahman MA, Nizkorodov SA, Al-Abadleh HA. Effect of Oxalate and Sulfate on Iron-Catalyzed Secondary Brown Carbon Formation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6708-6717. [PMID: 31034222 DOI: 10.1021/acs.est.9b00237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Oxalate and sulfate are ubiquitous components of ambient aerosols with a high complexation affinity to iron. However, their effect on iron-driven secondary brown carbon formation in solution from soluble aromatic and aliphatic reagents was not studied. We report masses and hydrodynamic particle sizes of insoluble particles formed from the dark aqueous phase reaction of catechol, guaiacol, fumaric, and muconic acids with Fe(III) in the presence of oxalate or sulfate. Results show that oxalate decreases particle yield in solution from the reaction of Fe(III), with a stronger effect for guaiacol than catechol. For both compounds, the addition of sulfate results in the formation of more polydisperse (0.1-5 μm) and heavier particles than those from control experiments. Reactions with fumaric and muconic acids show that oxalate (not sulfate) and pH are determining factors in the efficiency of particle formation in solution. Polymerization reactions occur readily in the presence of sulfate in solution producing particles with iron-coordinated and/or pore-trapped sulfate anions. The addition of oxalate to the reactions of Fe(III) with all organics, except guaiacol, produced fewer and larger polymeric particles (>0.5 μm). These results imply that even in the presence of competing ligands, the formation of insoluble and colored particles from soluble organic precursors still dominates over the formation of soluble iron complexes.
Collapse
Affiliation(s)
- Aseel Al Nimer
- Department of Chemistry and Biochemistry , Wilfrid Laurier University , Waterloo , ON N2L 3C5 , Canada
| | - Laura Rocha
- Department of Chemistry and Biochemistry , Wilfrid Laurier University , Waterloo , ON N2L 3C5 , Canada
| | - Mohammad A Rahman
- Department of Chemistry and Biochemistry , Wilfrid Laurier University , Waterloo , ON N2L 3C5 , Canada
| | - Sergey A Nizkorodov
- Department of Chemistry , University of California , Irvine , CA 92697 , United States
| | - Hind A Al-Abadleh
- Department of Chemistry and Biochemistry , Wilfrid Laurier University , Waterloo , ON N2L 3C5 , Canada
| |
Collapse
|
45
|
Wang N, Jing B, Wang P, Wang Z, Li J, Pang S, Zhang Y, Ge M. Hygroscopicity and Compositional Evolution of Atmospheric Aerosols Containing Water-Soluble Carboxylic Acid Salts and Ammonium Sulfate: Influence of Ammonium Depletion. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6225-6234. [PMID: 30938517 DOI: 10.1021/acs.est.8b07052] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Water-soluble organic acid salts are important components of atmospheric aerosols. Despite their importance, it is still not clear how water-soluble organic acid salts influence interactions between aerosols and water vapor in the atmosphere. In this study, the hygroscopic behaviors and chemical compositions of aerosol particles containing water-soluble organic acid salt ((CH2) n(COONa)2, n = 0, 1, 2) and (NH4)2SO4 were measured using in situ attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The ammonium depletion due to release of gaseous NH3 was found in mixed aerosols composed of (CH2) n(COONa)2 ( n = 1, 2) and (NH4)2SO4 upon dehydration. The ammonium loss could modify the aerosol composition, resulting in the formation of corresponding organic acid and monosodium dicarboxylate in mixed particles with high and low (NH4)2SO4 content, respectively. Due to the weaker hydrolysis of oxalate anions, the ammonium depletion was not observed for the Na2C2O4/(NH4)2SO4 mixtures. The changes in the particle composition led to the decreased water uptake upon hydration as compared to that upon dehydration. Our findings reveal that interactions between water-soluble organic acid salts and (NH4)2SO4 in aqueous aerosols may affect the repartition of NH3 between the condensed and gas phases, thus modifying composition and physicochemical properties of aerosols as well as relevant chemical processes.
Collapse
Affiliation(s)
- Na Wang
- School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 100081 , People's Republic of China
| | - Bo Jing
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
| | - Pan Wang
- School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 100081 , People's Republic of China
| | - Zhen Wang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Jiarong Li
- School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 100081 , People's Republic of China
| | - Shufeng Pang
- School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 100081 , People's Republic of China
| | - Yunhong Zhang
- School of Chemistry and Chemical Engineering , Beijing Institute of Technology , Beijing 100081 , People's Republic of China
| | - Maofa Ge
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021 , People's Republic of China
| |
Collapse
|
46
|
Phan CM. Independent surface action at the air/water surface: A renewed concept via artificial neural network. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.01.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
47
|
Marsh A, Rovelli G, Song YC, Pereira KL, Willoughby RE, Bzdek BR, Hamilton JF, Orr-Ewing AJ, Topping DO, Reid JP. Accurate representations of the physicochemical properties of atmospheric aerosols: when are laboratory measurements of value? Faraday Discuss 2018; 200:639-661. [PMID: 28574570 DOI: 10.1039/c7fd00008a] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Laboratory studies can provide important insights into the processes that occur at the scale of individual particles in ambient aerosol. We examine the accuracies of measurements of core physicochemical properties of aerosols that can be made in single particle studies and explore the impact of these properties on the microscopic processes that occur in ambient aerosol. Presenting new measurements, we examine here the refinements in our understanding of aerosol hygroscopicity, surface tension, viscosity and optical properties that can be gained from detailed laboratory measurements for complex mixtures through to surrogates for secondary organic atmospheric aerosols.
Collapse
|
48
|
The Impact of Divalent Cations on the Enrichment of Soluble Saccharides in Primary Sea Spray Aerosol. ATMOSPHERE 2018. [DOI: 10.3390/atmos9120476] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Field measurements have shown that sub-micrometer sea spray aerosol (SSA) is significantly enriched in organic material, of which a large fraction has been attributed to soluble saccharides. Existing mechanistic models of SSA production struggle to replicate the observed enhancement of soluble organic material. Here, we assess the role for divalent cation mediated co-adsorption of charged surfactants and saccharides in the enrichment of soluble organic material in SSA. Using measurements of particle supersaturated hygroscopicity, we calculate organic volume fractions for molecular mimics of SSA generated from a Marine Aerosol Reference Tank. Large enhancements in SSA organic volume fractions (Xorg > 0.2) were observed for 50 nm dry diameter (dp) particles in experiments where cooperative ionic interactions were favorable (e.g., palmitic acid, Mg2+, and glucuronic acid) at seawater total organic carbon concentrations (<1.15 mM C) and ocean pH. Significantly smaller SSA organic volume fractions (Xorg < 1.5 × 10−3) were derived from direct measurements of soluble saccharide concentrations in collected SSA with dry diameters <250 nm, suggesting that organic enrichment is strongly size dependent. The results presented here indicate that divalent cation mediated co-adsorption of soluble organics to insoluble surfactants at the ocean surface may contribute to the enrichment of soluble saccharides in SSA. The extent to which this mechanism explains the observed enhancement of saccharides in nascent SSA depends strongly on the concentration, speciation, and charge of surfactants and saccharides in the sea surface microlayer.
Collapse
|
49
|
Rahman M, Al-Abadleh HA. Surface Water Structure and Hygroscopic Properties of Light Absorbing Secondary Organic Polymers of Atmospheric Relevance. ACS OMEGA 2018; 3:15519-15529. [PMID: 31458208 PMCID: PMC6644084 DOI: 10.1021/acsomega.8b02066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/01/2018] [Indexed: 06/09/2023]
Abstract
Hygroscopic properties and chemical reactivity of secondary organic aerosols (SOA) influence their overall contribution to the indirect effect on the climate. In this study, we investigate the hygroscopic properties of organic and organometallic polymeric particles, namely polycatechol, polyguaiacol, Fe-polyfumarte, and Fe-polymuconate. These particles efficiently form in iron-catalyzed reactions with aromatic and aliphatic dicarboxylic acid compounds detected in field-collected SOA. The structure of surface water was studied using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and the uptake of gas water was quantified using quartz crystal microbalance (QCM) as a function of relative humidity. Spectroscopic data show that water bonding with organic functional groups acting as hydrogen bond acceptors causes shifts in their vibrational modes. Analysis of the hydroxyl group stretching region revealed weak and strong hydrogen bonding networks that suggest cluster formation reflecting water-water and water-organics interactions, respectively. A modified Type II multilayer Brunauer-Emmett-Teller adsorption model described the adsorption isotherm on the nonporous materials, polycatechol, polyguaiacol, and Fe-polymuconate. However, water adsorption on porous Fe-polyfumarate was best described using a Type V adsorption model, namely the Langmuir-Sips model that accounts for condensation in pores. The data revealed that organometallic polymers are more hygroscopic than organic polymers. The implications of these investigations are discussed in the context of the chemical reactivity of these particles relative to known SOA.
Collapse
|
50
|
Wingen LM, Finlayson-Pitts BJ. Probing surfaces of atmospherically relevant organic particles by easy ambient sonic-spray ionization mass spectrometry (EASI-MS). Chem Sci 2018; 10:884-897. [PMID: 30774883 PMCID: PMC6346289 DOI: 10.1039/c8sc03851a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/01/2018] [Indexed: 12/12/2022] Open
Abstract
EASI-MS is a promising technique for probing the chemical structures of inhomogeneous airborne organic particles.
Both ambient and laboratory-generated particles can have a surface composition different from the bulk, but there are currently few analytical techniques available to probe these differences. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) was applied to solid, laboratory-generated particles with core–shell morphologies formed from a variety of dicarboxylic acids. The soft ionization facilitated parent peak detection for the two compounds, from which the depth probed could be determined from the relative signal intensities. Two different configurations of a custom-made nebulizer are reported that yield different probe depths. In the “orthogonal mode,” with the nebulizer ∼10 centimeters away from the particle stream and at a 90° angle to the MS inlet, evaporation of the nebulizer droplets forms ions before interaction with the particles. The probe depth for orthogonal mode EASI-MS is shown to be 2–4 nm in these particle systems. In the “droplet mode”, the nebulizer and particle streams are in close proximity to each other and the MS inlet so that the particles interact with charged liquid droplets. This configuration resulted in full dissolution of the particles and gives particle composition similar to that from collection on filters and extraction of the particles (bulk). These studies establish that EASI-MS is a promising technique for probing the chemical structures of inhomogeneous airborne organic particles.
Collapse
Affiliation(s)
- L M Wingen
- Department of Chemistry , University of California Irvine , Irvine , CA 92697-2025 , USA . ; Tel: +1-949-824-7670
| | - B J Finlayson-Pitts
- Department of Chemistry , University of California Irvine , Irvine , CA 92697-2025 , USA . ; Tel: +1-949-824-7670
| |
Collapse
|