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Titel |
Carbamazepine as indicator for potential short-term contamination of karst springs |
VerfasserIn |
J. Doummar, M. Baierl, K. Noedler, T. Licha, M. Sauter, T. Geyer |
Konferenz |
EGU General Assembly 2012
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 14 (2012) |
Datensatznummer |
250068747
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Zusammenfassung |
Karst aquifers are complex systems which vulnerability is very difficult to assess mainly
because of the duality of recharge processes and duality of flow. Recharge to a karst aquifer
occurs as diffuse or concentrated (sinkholes and dolines). Moreover, karst aquifers are formed
by an unsaturated zone comprising soil, epikarst and unsaturated rock matrix, and a saturated
zone formed of highly permeable conduits and low permeability matrix storage. In the
case of contamination of groundwater by wastewater effluent polluted water can be
either transported rapidly and have short term major risk on spring water quality
or infiltrate into fractured rock matrix and therefore have a long term effect on
the water quality. In order to identify the risk of wastewater infiltrating into an
aquifer, researches have focused to date on the identification of indicative wastewater
markers.
Carbamazepine (CBZ) was frequently detected in surface water as well as in effluents of
sewage treatment plants, as less than 10% of carbamazepine are usually eliminated during
sewage treatment. Moreover, CBZ is not attenuated in aquifers (Heberer, 2002), is unlikely
degradable or adsorbed, and can be detected in groundwater (Clara et al., 2004). Therefore,
CBZ is considered to be fairly persistent in groundwater (Tixier et al., 2003), and is
consequently regarded as an effective wastewater marker.
In this case study, the Jeita spring in Lebanon (spring discharge: 1-20 m3/s) was
monitored and sampled for major ions and micro-pollutants following a combined
precipitation/snowmelt events. A total of 28 samples (major ions and micro-pollutants) were
taken over a total sampling time of 16 days at interval varying between 4 and 24 hours. Based
on the variation with time of discharge and electrical conductivity (monitored every 20
minutes) as well as the concentrations of the major ions, a conceptual model showing the
response of the aquifer compartments to the precipitation event was generated. A
breakthrough curve of the persistent micro-pollutant carbamazepine shows that CBZ enters
the aquifer system through rapid flow pathways, whereas it is heavily diluted with old CBZ
free waters stored in the soil/ epikarst zone released as a response to the precipitation
event. Furthermore, based on travel times estimated from artificial tracer tests, the
distance to the contamination source was estimated and reveals to be relatively
small.
References
Clara, M., Strenn, B., Kreuzinger, N., 2009.Carbamazepine as a possible anthropogenic
marker in the aquatic environment: investigation on the behavior of Carbamazepine in
wastewater treatment and during groundwater infiltration, Water Res. 38, 947–954.
Heberer, Th., 2002. Occurrence, fate, and removal of pharmaceutical residues
in the aquatic environment: a review of recent research data. Toxicol. Lett. 131,
5–17.
Tixier, C., Singer, H.P., Oellers, S., Müller,R.R., 2003.Occurrence and fate of
carbamazepine, clofibric acid, diclofenac, ibuproen, keteprofen, and naproxen in surface
waters, Environ. Sci. Technol. 37, 1061–1068. |
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