1
|
He J, Zhang H, Wang W, Ma Y, Yang M, He Y, Liu Z, Yu K, Jiang J. Probing autoxidation of oleic acid at air-water interface: A neglected and significant pathway for secondary organic aerosols formation. ENVIRONMENTAL RESEARCH 2022; 212:113232. [PMID: 35398317 DOI: 10.1016/j.envres.2022.113232] [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: 09/23/2021] [Revised: 02/27/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
Fatty acids have been proposed to be a potential source of precursors for SOAs, but the autoxidation process was neglected in the oxidation studies. Here, the autoxidation of oleic acid was explored using microdroplet mass spectrometry. Bulk solution, concentration and solvent composition experiments provided direct evidences for that the autoxidation occurred at or near the air-water interface. The kinetic data showed an acceleration at this interface and was comparable to ozonation, indicating that autoxidation is an important pathway for SOAs formation. In addition, intermediates/products were captured and identified using tandem mass spectrometry, spin-trapping and quenched agents. The autoxidation mechanism was divided into addition intermediates (AIs) and Criegee intermediates (CIs) pathways mediated by hydroxyl radicals (OH). The CI chemistry which is ubiquitous in gas phase was observed at the air-water interface, and this leaded to the mass/volume loss of aerosols. Inversely, the AI chemistry caused the increase of mass, density and hygroscopicity of aerosols. AI chemistry was dominated compared to CI chemistry, but varied by concerning aerosol sizes, ultraviolet light (UV) and charge. Moreover, the MS approach of selectively probing the interfacial substances at the scale of sub-seconds opens new opportunities to study heterogeneous chemistry in atmosphere.
Collapse
Affiliation(s)
- Jing He
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China
| | - Hong Zhang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong, 264209, PR China.
| | - Wenxin Wang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong, 264209, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China
| | - Yingxue Ma
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong, 264209, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China
| | - Miao Yang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong, 264209, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China
| | - Yuwei He
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong, 264209, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China
| | - Zhuo Liu
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong, 264209, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China
| | - Kai Yu
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong, 264209, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China
| | - Jie Jiang
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, 150090, PR China.
| |
Collapse
|
2
|
Seager S, Petkowski JJ, Gao P, Bains W, Bryan NC, Ranjan S, Greaves J. The Venusian Lower Atmosphere Haze as a Depot for Desiccated Microbial Life: A Proposed Life Cycle for Persistence of the Venusian Aerial Biosphere. ASTROBIOLOGY 2021; 21:1206-1223. [PMID: 32787733 DOI: 10.1089/ast.2020.2244] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We revisit the hypothesis that there is life in the venusian clouds to propose a life cycle that resolves the conundrum of how life can persist aloft for hundreds of millions to billions of years. Most discussions of an aerial biosphere in the venusian atmosphere temperate layers never address whether the life-small microbial-type particles-is free floating or confined to the liquid environment inside cloud droplets. We argue that life must reside inside liquid droplets such that it will be protected from a fatal net loss of liquid to the atmosphere, an unavoidable problem for any free-floating microbial life forms. However, the droplet habitat poses a lifetime limitation: Droplets inexorably grow (over a few months) to large enough sizes that are forced by gravity to settle downward to hotter, uninhabitable layers of the venusian atmosphere. (Droplet fragmentation-which would reduce particle size-does not occur in venusian atmosphere conditions.) We propose for the first time that the only way life can survive indefinitely is with a life cycle that involves microbial life drying out as liquid droplets evaporate during settling, with the small desiccated "spores" halting at, and partially populating, the venusian atmosphere stagnant lower haze layer (33-48 km altitude). We, thus, call the venusian lower haze layer a "depot" for desiccated microbial life. The spores eventually return to the cloud layer by upward diffusion caused by mixing induced by gravity waves, act as cloud condensation nuclei, and rehydrate for a continued life cycle. We also review the challenges for life in the extremely harsh conditions of the venusian atmosphere, refuting the notion that the "habitable" cloud layer has an analogy in any terrestrial environment.
Collapse
Affiliation(s)
- Sara Seager
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Janusz J Petkowski
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Peter Gao
- Department of Astronomy, University of California at Berkeley, California, USA
| | - William Bains
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Noelle C Bryan
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Sukrit Ranjan
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jane Greaves
- School of Physics and Astronomy, Cardiff University, Cardiff, United Kingdom
- Institute of Astronomy, Cambridge University, Cambridge, United Kingdom
| |
Collapse
|
3
|
Geppert WD, Larsson M. Experimental Investigations into Astrophysically Relevant Ionic Reactions. Chem Rev 2013; 113:8872-905. [DOI: 10.1021/cr400258m] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wolf D. Geppert
- Department
of Physics, AlbaNova
University Center, Stockholm University, Roslagstullsbacken 21, Stockholm SE-10691, Sweden
| | - Mats Larsson
- Department
of Physics, AlbaNova
University Center, Stockholm University, Roslagstullsbacken 21, Stockholm SE-10691, Sweden
| |
Collapse
|