INGEIS   05370
INSTITUTO DE GEOCRONOLOGIA Y GEOLOGIA ISOTOPICA
Unidad Ejecutora - UE
artículos
Título:
Evidencias de pluma de contaminación detectadas por métodos geofísicos en el Basurero Municipal de Gualeguaychú, Entre Ríos, Argentina
Autor/es:
POMPOSIELLO, MARIA CRISTINA; BOUJON, PAMELA; DAPEÑA, CRISTINA; FAVETTO, ALICIA
Revista:
Revista Latino-Americana de Hidrogeología
Editorial:
Universidad Federal do Parana (UFPR)- ProReitoria de Pesquisa e Pós-Graduaçãò (PRPPG)
Referencias:
Lugar: Curitiba; Año: 2006 vol. 6
ISSN:
1676-0999
Resumen:
This paper presents the geophysical results of a multidisciplinary project at an urban solid waste in Gualeguaychú, Province of Entre Ríos, Argentina (Figure 1). Several geoelectric studies, horizontal profiling and vertical sounding using dipole-dipole and Schlumberger electrode configurations respectively and GPR profiles (antennas 150MHz -500MHz) were performed within and outside the landfill (Figure 2). The 2D model obtained within the landfill shows a shallow layer with a thickness of 2 m - 3 m and a resistivity range from 100 to 1000 ohm-m. The second layer is about 4 m - 5 m thick and presents low values of resistivity between 3 ohm-m and 6 ohm-m, which are indicating a contaminated zone that is located below the water table. The third layer has a thickness of more than 10 m and a resistivity of around 15 ohm-m. Below this depth it is observed another conductive layer (5 ohm-m) (Figures 3, 4, 6, 8) which is also observed in the 2D model obtained outside the landfill boundaries at the same depth (level) (Figure 10). The water table was determined to be at 2 m - 3 m deep by GPR survey (Figure 7). The GPR profiles have identified the upper limit of the contaminant plume by the absence of reflectors or very weak signals (Figures 5 y 7). In such zone the 2D resistivity model shows the presence of high electrical conductivity materials, which do not allow propagation of the radar waves deeper. The geoelectric studies and GPR results show a good correlation and their integrated interpretations were supported by regional geology. In addition, from electric conductivity values of the most conductive sections were predicted leachate geochemical parameters applying empiric relations (Table 1). In particular the groundwater electrical conductivity was estimated and in general, it has analogous values to the conductivity determined from superficial waters and lower values than those measured in phreatic wells.