Demonstrating a Natural Origin of Chloroform in Groundwater Using Stable Carbon Isotopes
| Autor: | Florian Breider, Troels Laier, Ole Stig Jacobsen, Daniel Hunkeler |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
010504 meteorology & atmospheric sciences
Water table Denmark 010501 environmental sciences 01 natural sciences chemistry.chemical_compound Industry Environmental Chemistry Groundwater 0105 earth and related environmental sciences Isotope analysis Carbon Isotopes Chloroform Geography Chemistry Soil organic matter Soil gas General Chemistry 15. Life on land 6. Clean water 13. Climate action Isotopes of carbon Isotope Labeling Environmental chemistry Soil water Water Pollutants Chemical |
| Zdroj: | ENVIRONMENTAL SCIENCE & TECHNOLOGY |
| Popis: | Chloroform has been for a long time considered only as an anthropogenic contaminant. The presence of chloroform in forest soil and groundwater has been widely demonstrated. The frequent detection of chloroform in groundwater in absence of other contaminants suggests that chloroform is likely produced naturally. Compound-specific isotope analysis of chloroform was performed on soil-gas and groundwater samples to elucidate whether its source is natural or anthropogenic. The δ13C values of chloroform (−22.8 to −26.2‰) present in soil gas collected in a forested area are within the same range as the soil organic matter (−22.6 to −28.2‰) but are more enriched in 13C compared to industrial chloroform (−43.2 to −63.6‰). The δ13C values of chloroform at the water table (−22.0‰) corresponded well to the δ13C of soil gas chloroform, demonstrating that the isotope signature of chloroform is maintained during transport through the unsaturated zone. Generally, the isotope signature of chloroform is conserved also during longer range transport in the aquifer. These δ13C data support the hypothesis that chloroform is naturally formed in some forest soils. These results may be particularly relevant for authorities’ regulation of chloroform which in the case of Denmark was very strict for groundwater ( |
| Databáze: | OpenAIRE |
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