Title: Co²⁺ sorption capacity indicators of La Plata region's soils: insights and correlations with soil properties

Authors: M.L. Montes; M.A. Fernández; J. Brendlé; L. Michelin; M.A. Taylor; R.M. Torres Sánchez

Addresses: IFLP, Instituto de Física La Plata – CONICET CCT-La Plata, Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina. Diagonal 113 y 64, 1900, La Plata, Argentina ' CETMIC – CONICET – CCT La Plata, CICBA. Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina. Camino Centenario y 506, 1897, M.B. Gonnet, La Plata, Argentina ' Axe Matériaux à Porosité Contrôlée, Institut de Science des Matériaux, Institut de Recherche Jean-Baptiste Donnet, 3 bis rue A. Werner, Mulhouse Cedex, 68093, France ' Axe Matériaux à Porosité Contrôlée, Institut de Science des Matériaux, Institut de Recherche Jean-Baptiste Donnet, 3 bis rue A. Werner, Mulhouse Cedex, 68093, France ' IFLP, Instituto de Física La Plata – CONICET CCT-La Plata, Facultad de Ingeniería Universidad Nacional de La Plata, Diagonal 113 y 64, 1900, La Plata, Argentina ' CETMIC – CONICET – CCT La Plata, CICBA, Camino Centenario y 506, 1897, M.B. Gonnet, La Plata, Argentina

Abstract: Notwithstanding that the soil acts as a pollutant sink, its Co sorption capacity presents still controversial results. Here, Co²⁺sorption on soil samples from La Plata (Argentina) was analysed. Four sorption indicators were used: K_dis (estimated from the entire sorption isotherm), K_F1 (estimated from the lineal part of the sorption isotherm), K_dx, (solid-solution distribution coefficient) and K_r, a dimensionless parameter recently developed. Pearson correlation coefficients between the parameters and soil properties were calculated. Significant and negative correlations with silt were obtained, whereas significant and positive correlations were established with clay and smectite content. Soil clay fractions were isolated and Co²⁺ sorption was evaluated, observing relatively high removal. The correlations with kaolinite, magnetite and Mn and Fe oxides showed debatable results: K_dis could be more sensitive than K_r to magnetite variations whereas K_r seems to be more sensitive to Mn changes. K_F1 presented similar behaviour to K_r. The studied soils presented a high Co²⁺ sorption capacity, making them an effective barrier of this pollutant, avoiding its passage to groundwater and crops.

Keywords: cobalt sorption; soil/clay; isotherms; distribution coefficients; correlations; soil properties.

DOI: 10.1504/IJENVH.2019.100589

International Journal of Environment and Health, 2019 Vol.9 No.3, pp.224 - 237

Received: 20 Dec 2018
Accepted: 04 Feb 2019
Published online: 04 Jul 2019 *

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