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| Titel |
Assessing anthropogenic pressures on groundwater using stable OH isotopes: perspectives and issues |
| VerfasserIn |
Philippe Négrel, Patrick Ollivier, Christine Flehoc, Daniel Hube |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250109425
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| Publikation (Nr.) |
 EGU/EGU2015-9331.pdf |
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| Zusammenfassung |
| Large developments of isotope hydrogeology were done and well-established techniques
mainly applying stable isotopes of the water molecule (hydrogen and oxygen) are now
used largely to trace water provenance but also recharge processes. New methods
allow the use of non-traditional isotopes (metals, compound specific stable isotope
analysis CSIA/¦) to trace anthropogenic pressures in surface- and groundwater.
Groundwater contamination in large industrial sites may come from several origins
such as leakage from tanks during the production process of chemical products,
liquid storage tanks, solid end product or past accumulated product in soil which is
released over the time. The understanding of the origin and the further evolution of the
chemical contamination in groundwater in an industrial site issued from past or
current industrial activities is essential for the industrial companies regarding their
environmental policies. The objective of this study was to use with an innovative
way the stable isotopes of the water molecule as a low cost tool to trace pollutant
plumes in groundwater and help to a better management of contaminated industrial
sites.
We present data on stable isotopes O and H in an European region where electrochemistry
plants occur. For confidentiality purposes, the sites remain anonymous. Present day industrial
activities have a direct impact on the groundwater over the site and migration of the
contaminant(s) plume out of the site is supposed.
We first characterize the natural groundwater background through the O-H
characterization of surface water, lakes, thermal waters and regional shallow aquifers. High
and low altitude recharge can be demonstrated in the area. Secondly, we used the
stable isotope of the water molecule to trace over the site the impact of the Cl-rich
liquor manufacturing process. Large deuterium enrichment was evidenced in the
groundwater and the high values can be related to a direct contamination of the
groundwater through leakage of Cl-rich liquor with a δD values up to 400oȦfter
technical operations to improve sealing of the liquid storage tanks, no evidence
of δD enrichment can be shown in present day groundwater. All values are along
the global meteoric water line even for wells previously H-enriched, reflecting the
absence of new leakage from tanks or during the manufacturing process over the site.
Therefore our study shows that the stable isotopes of the water molecule can also be
successfully used in an innovative way to trace pollutant plumes in groundwater. |
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