Analysis of Arsenic Pollution in Groundwater Aquifers by XRF

V. SBARATO; H. J. SÁNCHEZ

APPLIED RADIATION AND ISOTOPES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2000 vol. 54 p. 737 - 741

0969-8043

The serious contamination of groundwater in the southeastern plain of the province of Co rdoba (Argentina), a phenomenon mentioned in the literature for over 80 years, has given rise to this initial hydrologic study covering an area over 250km2. This study analyzes a rural area near a little town called La Francia, and is motivated by the existence of an important pollution with arsenic in the ®rst-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 ¯uorescence (XRF) technique, and using an energy-dispersive spectrometer, 50 samples of groundwater of the rural zone of La Francia from about 100m deep (second aquifer), were analyzed. The samples were excited with a 3kW X-ray tube and measured using a re¯ecting geometry with 458 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 quanti®cation. A high percentage of the analyzed samples showed concentrations lesser than or equal to 0.05mglÿ1. This value corresponds to the maximum pollutant level for humans. The maximum measured value reaches 3mg lÿ1 in samples collected in perforations of ®rst-aquifer wells and in some second-aquifer isolated wells. # 2001 Elsevier Science Ltd. All rights reserved.