Isotopic composition of natural and synthetic chlorate (δ18O, Δ17O, δ37Cl, 36Cl/Cl): Methods and initial results

Jackson, W. A.; Brundrett, Maeghan; Böhlke, John K.; Hatzinger, Paul B.; Mroczkowski, S.; Sturchio, Neil C.

doi:10.1016/j.chemosphere.2021.129586

Cited by 7 publications

(2 citation statements)

References 48 publications

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“…These experimentally derived results can be applied in future field investigations in DNAN-impacted sites to help understand which natural attenuation processes may be affecting the environmental fate of DNAN. The enrichment factors can also be used to determine the extent of DNAN transformation once the main degradation pathway has been identified, as demonstrated in prior studies with RDX, , herbicides, − insecticides, − pharmaceuticals, − chlorinated solvents, − and perchlorate. − Nonetheless, considerable uncertainties remain because of the inherent complexities encountered in the subsurface, in terms of both the functions of the native microbial communities and the variations in mineralogy and groundwater geochemistry.…”

Section: Resultsmentioning

confidence: 99%

Carbon and Nitrogen Isotope Fractionations During Biotic and Abiotic Transformations of 2,4-Dinitroanisole (DNAN)

Wang,

Fuller,

Murillo-Gelvez

et al. 2024

Environ. Sci. Technol.

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2,4-Dinitroanisole (DNAN) is a main constituent in various new insensitive munition formulations. Although DNAN is susceptible to biotic and abiotic transformations, in many environmental instances, transformation mechanisms are difficult to resolve, distinguish, or apportion on the basis solely of analysis of concentrations. We used compound-specific isotope analysis (CSIA) to investigate the characteristic isotope fractionations of the biotic (by three microbial consortia and three pure cultures) and abiotic (by 9,10-anthrahydroquinone-2-sulfonic acid [AHQS]) transformations of DNAN. The correlations of isotope enrichment factors (Λ N/C ) for biotic transformations had a range of values from 4.93 ± 0.53 to 12.19 ± 1.23, which is entirely distinct from Λ N/C values reported previously for alkaline hydrolysis, enzymatic hydrolysis, reduction by Fe 2+ -bearing minerals and iron-oxide-bound Fe 2+ , and UV-driven phototransformations. The Λ N/C value associated with the abiotic reduction by AHQS was 38.76 ± 2.23, within the range of previously reported values for DNAN reduction by Fe 2+ -bearing minerals and iron-oxide-bound Fe 2+ , albeit the mean Λ N/C was lower. These results enhance the database of isotope effects accompanying DNAN transformations under environmentally relevant conditions, allowing better evaluation of the extents of biotic and abiotic transformations of DNAN that occur in soils, groundwaters, surface waters, and the marine environment.

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Section: Resultsmentioning

confidence: 99%

Carbon and Nitrogen Isotope Fractionations During Biotic and Abiotic Transformations of 2,4-Dinitroanisole (DNAN)

Wang,

Fuller,

Murillo-Gelvez

et al. 2024

Environ. Sci. Technol.

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“…Differences in chlorine and nitrogen oxyanion ratios in these environments could be due to the relative contributions of production mechanisms or post-formation stability of these species. On the earth, ClO 4 – , and to a smaller degree ClO 3 – , is mainly produced in the stratosphere by O 3 or UV oxidation based on 36 Cl and Δ 17 O composition. − NO 3 – production, excluding direct and indirect anthropogenic contributions, is also attributed to UV and O 3 oxidation. Due to the lack of isotopic composition data, the production mechanism(s) responsible for NO 3 – and ClO x – on Mars and other solar bodies is unclear but could be due to similar reactions as well as other reactions not pertinent to the earth. , Once formed, ClO 4 – , ClO 3 – , and NO 3 – may undergo transformation via biological or chemical processes.…”

Section: Introductionmentioning

confidence: 99%

Abiotic Reduction of Nitrate and Chlorate by Green Rust

Zhang

Yan

Messan

et al. 2021

ACS Earth Space Chem.

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Fe-rich minerals are ubiquitous on the earth’s surface and on Mars, and interactions of iron minerals with chlorate (ClO3 –) and/or nitrate (NO3 –) may influence the redox cycling of chlorine and nitrogen in the terrestrial and Martian environments. The objective of this study was to investigate the reactivity of two different types of synthesized green rusts (GRs), chloride (Cl-GR) and sulfate (SO4-GR), for ClO3 – and NO3 – reduction. Cl-GR and SO4-GR were synthesized by co-precipitation from an FeII–FeIII (ferrous iron and ferric iron) solution with the addition of NaOH. Both Cl-GR and SO4-GR degraded ClO3 – much faster than NO3 –. There were no significant competitive effects on the reduction of ClO3 – or NO3 – when both species were present simultaneously. The FeII/FeIII ratio in GR had a strong influence on the rates and the extents of oxyanion transformation. Cl-GR with an FeII/FeIII ratio of 2:1 and 3:1 showed higher reactivity than 1:1 Cl-GR for both ClO3 – and NO3 – reduction. In comparison, SO4-GR with an FeII/FeIII ratio of 1:1 transformed ClO3 – at a higher rate than at FeII/FeIII ratios of 2:1 and 3:1. The pH effect was studied within a pH range of 4.5–8.5. More complete ClO3 – and NO3 – transformation was achieved at pH 4.5, and the apparent reaction rate constants decreased with increasing pH. In all experiments, nearly 100% of the initial ClO3 – (10 mg/L) was degraded by GR except for Cl-GR with an FeII/FeIII ratio of 1:1 at pH 8.5. However, for NO3 –, there was an initial rapid transformation followed by a period of slow or no transformation, implying the formation of passivating products that hindered continuous NO3 – reduction. FeII did not appear to degrade NO3 – or ClO3 – at detectable rates over the time period of interest (20 days), except at the highest concentration studied (1000 mg/L). The reactions between GR and ClO3 – or NO3 – have implications for the cycling of chlorine and nitrogen and the stability of iron minerals. On Mars, these reactions may help to understand the occurrence and distribution of ClO4 –, ClO3 –, and NO3 –.

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Mass-independent fractionation processes in the atmosphere

Hemingway,

Claire

2025

Treatise on Geochemistry

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Isotopic composition of natural and synthetic chlorate (δ18O, Δ17O, δ37Cl, 36Cl/Cl): Methods and initial results

Cited by 7 publications

References 48 publications

Carbon and Nitrogen Isotope Fractionations During Biotic and Abiotic Transformations of 2,4-Dinitroanisole (DNAN)

Carbon and Nitrogen Isotope Fractionations During Biotic and Abiotic Transformations of 2,4-Dinitroanisole (DNAN)

Abiotic Reduction of Nitrate and Chlorate by Green Rust

Mass-independent fractionation processes in the atmosphere

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