Mechanistic Aspects Regarding the Ultraviolet Degradation of Polychlorinated Biphenyls in Different Media: Insights from Carbon and Chlorine Isotope Fractionation

2021 ◽  
Author(s):  
Chenchen Huang ◽  
Yanhong Zeng ◽  
Ya Cao ◽  
Chuhong Zhu ◽  
Zihe Ren ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Isotope Fractionation ◽  
Chlorine Isotope

scholarly journals Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air

2015 ◽  
Vol 15 (12) ◽  
pp. 6867-6877 ◽  
Author(s):  
S. J. Allin ◽  
J. C. Laube ◽  
E. Witrant ◽  
J. Kaiser ◽  
E. McKenna ◽  
...  
Keyword(s):  
Isotope Fractionation ◽  
Isotope Composition ◽  
Stratospheric Ozone ◽  
Standard Uncertainty ◽  
Gas Chromatography Mass Spectrometry ◽  
Sources And Sinks ◽  
Chlorine Isotope ◽  
Tropospheric Measurements ◽  
Single Detector

Abstract. The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ϵapp) for mid- and high-latitude stratospheric samples are respectively −2.4 (0.5) and −2.3 (0.4) ‰ for CFC-11, −12.2 (1.6) and −6.8 (0.8) ‰ for CFC-12 and −3.5 (1.5) and −3.3 (1.2) ‰ for CFC-113, where the number in parentheses is the numerical value of the standard uncertainty expressed in per mil. Assuming a constant isotope composition of emissions, we calculate the expected trends in the tropospheric isotope signature of these gases based on their stratospheric 37Cl enrichment and stratosphere–troposphere exchange. We compare these projections to the long-term δ (37Cl) trends of all three CFCs, measured on background tropospheric samples from the Cape Grim air archive (Tasmania, 1978–2010) and tropospheric firn air samples from Greenland (North Greenland Eemian Ice Drilling (NEEM) site) and Antarctica (Fletcher Promontory site). From 1970 to the present day, projected trends agree with tropospheric measurements, suggesting that within analytical uncertainties, a constant average emission isotope delta (δ) is a compatible scenario. The measurement uncertainty is too high to determine whether the average emission isotope δ has been affected by changes in CFC manufacturing processes or not. Our study increases the suite of trace gases amenable to direct isotope ratio measurements in small air volumes (approximately 200 mL), using a single-detector gas chromatography–mass spectrometry (GC–MS) system.

scholarly journals Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air

2014 ◽  
Vol 14 (23) ◽  
pp. 31813-31841
Author(s):  
S. J. Allin ◽  
J. C. Laube ◽  
E. Witrant ◽  
J. Kaiser ◽  
E. McKenna ◽  
...  
Keyword(s):  
Isotope Fractionation ◽  
Isotope Composition ◽  
Stratospheric Ozone ◽  
Isotope Ratios ◽  
Gas Chromatography Mass Spectrometry ◽  
Chlorine Isotope ◽  
Site Model ◽  
Tropospheric Measurements ◽  
Single Detector

Abstract. The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ϵapp) for mid- and high-latitude stratospheric samples are (−2.4 ± 0.5) and (−2.3 ± 0.4)‰ for CFC-11, (−12.2 ± 1.6) and (−6.8 ± 0.8)‰ for CFC-12 and (−3.5 ± 1.5) and (−3.3 ± 1.2)‰ for CFC-113, respectively. Assuming a constant source isotope composition, we estimate the expected trends in the tropospheric isotope signature of these gases due to their stratospheric 37Cl enrichment and stratosphere–troposphere exchange. We compare these model results to the long-term δ(37Cl) trends of all three CFCs, measured on background tropospheric samples from the Cape Grim air archive (Tasmania, 1978–2010) and tropospheric firn air samples from Greenland (NEEM site) and Antarctica (Fletcher Promontory site). Model trends agree with tropospheric measurements within analytical uncertainties. From 1970 to the present-day, we find no evidence for variations in chlorine isotope ratios associated with changes in CFC manufacturing processes. Our study increases the suite of trace gases amenable to direct isotope ratio measurements in small air volumes, using a single-detector gas chromatography-mass spectrometry system.

Chlorine isotope fractionation associated with volcanic activity at the Kusatsu-Bandaiko hot spring in Japan

2008 ◽  
Vol 44 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Masaaki Musashi ◽  
Takao Oi ◽  
Hans G.M. Eggenkamp ◽  
Motoyuki Matsuo
Keyword(s):  
Volcanic Activity ◽  
Isotope Fractionation ◽  
Hot Spring ◽  
Chlorine Isotope

scholarly journals Chlor-Isotopenseparation an einem wasserhaltigen Zirkondioxidaustauscher / Chlorine Isotope Separation Using an Hydrous Zirconium Dioxide Exchanger

1980 ◽  
Vol 35 (5) ◽  
pp. 642-647 ◽  
Author(s):  
Klaus G. Heumann ◽  
Klaus Baier ◽  
Gerald Wibmer
Keyword(s):  
Anion Exchange ◽  
Zirconium Dioxide ◽  
Isotope Fractionation ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Isotope Separation ◽  
Chlorine Isotope ◽  
Basic Anion Exchange Resin ◽  
Basic Anion ◽  
Hydrous Zirconium

AbstractHydrous zirconium dioxide is used in column experiments for separating the halide ions as well as for isotope fractionation of chlorine. The preparation of the zirconium dioxide particles is carried out by homogeneous hydrolysis of a zirconyl chloride solution using hexamethylenetetramine. The separation order of the halides is I-, Br- and Cl- in contrast to the inverse separation order using a strongly basic anion exchange resin. In chlorine isotope separation experiments an enrichment of 35Cl- is found in the first fractions, whereas the last fractions show a significant enrichment of 37C1-. This also indicates an inversion of the isotope separation compared with a strongly basic anion exchange resin. A dependence of the isotope fractionation on the concentration of the NaNO3 solution used as eluant is found. With increasing concentration the isotope fractionation decreases. Using a 0.5 M NaNO3 solution the elementary separation effect was calculated e = 6,1 · 10-4 . This is one of the highest isotope fractionations known in a chloride isotope exchange system. The results show that the electrolyte behaviour of isotopes is comparable to that of a series of homologous elements.

scholarly journals Carbon and Chlorine Isotope Fractionation Patterns Associated with Different Engineered Chloroform Transformation Reactions

2017 ◽  
Vol 51 (11) ◽  
pp. 6174-6184 ◽  
Author(s):  
Clara Torrentó ◽  
Jordi Palau ◽  
Diana Rodríguez-Fernández ◽  
Benjamin Heckel ◽  
Armin Meyer ◽  
...  
Keyword(s):  
Isotope Fractionation ◽  
Chlorine Isotope

scholarly journals Halogen Element and Stable Chlorine Isotope Fractionation Caused by Fluid–Rock Interaction (Bamble Sector, SE Norway)

2015 ◽  
Vol 56 (2) ◽  
pp. 299-324 ◽  
Author(s):  
Christof Kusebauch ◽  
Timm John ◽  
Jaime D. Barnes ◽  
Andreas Klügel ◽  
Håkon O. Austrheim
Keyword(s):  
Isotope Fractionation ◽  
Rock Interaction ◽  
Chlorine Isotope ◽  
Se Norway ◽  
Bamble Sector

Chlorine Isotope Fractionation during Reductive Dechlorination of Chlorinated Ethenes by Anaerobic Bacteria

2002 ◽  
Vol 36 (20) ◽  
pp. 4389-4394 ◽  
Author(s):  
Masahiko Numata ◽  
Noboru Nakamura ◽  
Hiromoto Koshikawa ◽  
Yutaka Terashima
Keyword(s):  
Reductive Dechlorination ◽  
Isotope Fractionation ◽  
Anaerobic Bacteria ◽  
Chlorinated Ethenes ◽  
Chlorine Isotope

scholarly journals Chlorine isotope fractionation between chloride (Cl−) and dichlorine (Cl2)

2017 ◽  
Vol 213 ◽  
pp. 375-382 ◽  
Author(s):  
Thomas Giunta ◽  
Jabrane Labidi ◽  
Hans G.M. Eggenkamp
Keyword(s):  
Isotope Fractionation ◽  
Chlorine Isotope
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