Documents disponibles écrits par cet auteur

Metal transport parameters of a gneiss saprolitic silty soil for liner design / Monica Machado Stuermer in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°4 (Avril 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°4 (Avril 2008) . - pp. 509–518 Titre : Metal transport parameters of a gneiss saprolitic silty soil for liner design Type de document : texte imprimé Auteurs : Monica Machado Stuermer, Auteur ; Maria Eugenia Gimenez Boscov, Auteur ; Elisabeth de Oliveira, Auteur Année de publication : 2008 Article en page(s) : pp. 509–518 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Residual  soils  Compacted  soils  Sorption  Diffusion  Heavy  metals  Laboratory  tests  Silts  Parameters Résumé : Diffusion coefficients and retardation factors of two metal cations ( Cd2+ and Pb2+ ) were measured for a compacted Brazilian saprolitic soil derived from gneiss, aiming to assess its geoenvironmental performance as a liner for waste disposal sites. This soil occurs extensively all over the country in very thick layers, but has not been used in liners because of its hydraulic conductivity, higher than 10−9m/s when compacted at optimum water content of standard Proctor energy, but which can be reduced by means of appropriate compaction techniques or additives. Batch, column, and diffusion tests were carried out with monospecies synthetic solutions at pH 1, 3, and 5.5. Measured diffusion coefficients varied between 0.5 and 4×10−10m2/s . Retardation factors show that cadmium, a very mobile cation, is not adsorbed at pH 1 but is significantly retained at pH 3 and pH 5.5, whereas lead is retained at all tested pH values though slightly at pH 1. Estimated retardation factors from batch tests were 1.3–2.3 times those resulting from column tests and at its highest when obtained by diffusion tests; whereas batch tests allow a more complete exposure of the soil grains to the solution, time-dependent nonspecific adsorption may take longer to occur. The importance of contact time was observed and should be considered in further investigations. Its significant retention of metals suggests a promising utilization of this soil as a bottom liner for wastes landfills. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A4%2850 [...] [article] Metal transport parameters of a gneiss saprolitic silty soil for liner design [texte imprimé] / Monica Machado Stuermer, Auteur ; Maria Eugenia Gimenez Boscov, Auteur ; Elisabeth de Oliveira, Auteur . - 2008 . - pp. 509–518. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°4 (Avril 2008) . - pp. 509–518 Mots-clés : Residual  soils  Compacted  soils  Sorption  Diffusion  Heavy  metals  Laboratory  tests  Silts  Parameters Résumé : Diffusion coefficients and retardation factors of two metal cations ( Cd2+ and Pb2+ ) were measured for a compacted Brazilian saprolitic soil derived from gneiss, aiming to assess its geoenvironmental performance as a liner for waste disposal sites. This soil occurs extensively all over the country in very thick layers, but has not been used in liners because of its hydraulic conductivity, higher than 10−9m/s when compacted at optimum water content of standard Proctor energy, but which can be reduced by means of appropriate compaction techniques or additives. Batch, column, and diffusion tests were carried out with monospecies synthetic solutions at pH 1, 3, and 5.5. Measured diffusion coefficients varied between 0.5 and 4×10−10m2/s . Retardation factors show that cadmium, a very mobile cation, is not adsorbed at pH 1 but is significantly retained at pH 3 and pH 5.5, whereas lead is retained at all tested pH values though slightly at pH 1. Estimated retardation factors from batch tests were 1.3–2.3 times those resulting from column tests and at its highest when obtained by diffusion tests; whereas batch tests allow a more complete exposure of the soil grains to the solution, time-dependent nonspecific adsorption may take longer to occur. The importance of contact time was observed and should be considered in further investigations. Its significant retention of metals suggests a promising utilization of this soil as a bottom liner for wastes landfills. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A4%2850 [...]