Analysis of arsenic pollution in groundwater aquifers by X-ray fluorescence.
The serious contamination of groundwater in the southeastern plain of the province of Córdoba (Argentina), a phenomenon mentioned in the literature for over 80 years, has given rise to this initial hydrologic study covering an area over 250 km2. This study analyzes a rural area near a little town called La Francía, and is motivated by the existence of an important pollution with arsenic in the first-aquifer groundwater of the region. This phenomenon has been mentioned for a long time and evidenced by the high incidence of diseases associated with this element in the local population. By means of the X-ray fluorescence (XRF) technique, and using an energy-dispersive spectrometer, 50 samples of groundwater of the rural zone of La Francia from about 100 m deep (second aquifer), were analyzed. The samples were excited with a 3 kW X-ray tube and measured using a reflecting geometry with 45 of incident and take-off directions. Preconcentration techniques for the preparation of the samples were employed in order to obtain an adequate signal-to-noise ratio. The As concentration in water was obtained using calibration curves and the internal standard method for quantification. A high percentage of the analyzed samples showed concentrations lesser than or equal to 0.05 mg l(-1). This value corresponds to the maximum pollutant level for humans. The maximum measured value reaches 3 mg l(-1) in samples collected in perforations of first-aquifer wells and in some second-aquifer isolated wells.
Observatorio Ambiental, Municipalidad de Córdoba, Argentina.
V M
VM
Sbarato
H J
HJ
Sánchez
D001118:Argentina; D001151:Arsenic / Q000032:analysis*; D005618:Fresh Water / Q000032:analysis*; D013052:Spectrometry, X-Ray Emission / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
D014874:Water Pollutants, Chemical; D001151:Arsenic