Precipitation of secondary phases of iron and its role in controlling the mobility of potentially toxic elements in soils in a semiarid river basin in Northwest Mexico
Por:
Ziegler-Rivera F.R.A., Prado, B., Robles-Morua, A., Mora, L., Mendez-Barroso, L., Archundia, D., Marquez, J., Caballero, L., Morales, E.
Publicada:
1 nov 2020
Ahead of Print:
1 ene 2020
Resumen:
Purpose: Soils have the ability to retain potentially toxic elements (PTEs) through different chemical processes that promote low mobility of these elements, such as the precipitation of secondary phases of Fe, which facilitate the adsorption/co-precipitation of PTEs. The main objective of this study was to evaluate the mobility of PTEs present in an acid solution in two soils with different concentrations of calcite, understanding the role of secondary iron phases in the retention of these elements. Materials and methods: To evaluate this phenomenon, intact soil columns of two different types of soils from the Sonora River in Northwest Mexico were exposed to an acid solution with high concentration of dissolved PTEs (mainly Fe, Al, and Cu). Results and discussion: The Tinajas soil was free of carbonates while the Bacanuchi soil had more carbonate content than the Tinajas soil. Secondary precipitates corresponding to secondary phases of iron (mainly ferrihydrite and jarosite) were identified by X-ray diffraction. Using scanning electron microscopy, the PTEs retained in the soils were identified. The presence of calcite favored the neutral pH values in the collected leachates in the Bacanuchi soil; consequently, the mobility of the PTEs present in the acid solution was nullified. Furthermore, this process facilitated the retention of the toxic elements in the Bacanuchi soil. Conclusions: The retention of PTEs was 100% in the Bacanuchi soil where the natural acid-neutralizing capacity in this soil was associated with calcite. The formation of secondary phases of Fe, among them ferrihydrite, jarosite, and schwertmannite, mainly in Bacanuchi soil, promoted the retention of Al, As, Cd, Cu, Fe, Mn, and Pb (elements analyzed in this work). Results of this work can provide key insights to improve cleanup and conservation strategies in mining sites. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
Filiaciones:
Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Mexico City, Mexico
Instituto de Geología, Universidad Nacional Autónoma de México, Mexico City, Mexico
Laboratorio Nacional de Geoquímica y Mineralogía, LANGEM, Mexico City, Mexico
Departamento de Ciencias del Agua y del Medio Ambiente, Instituto Tecnológico de Sonora, Ciudad Obregón, Mexico
Estación Regional Noreste, Instituto de Geología, Universidad Nacional Autónoma de México, Mexico City, Mexico
Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Mexico City, 04510, Mexico
Univ Nacl Autonoma Mexico, Posgrad Ciencias Tierra, Mexico City, DF, Mexico
(Corresponding Author), Univ Nacl Autonoma Mexico, Inst Geol, Mexico City, DF, Mexico
(Corresponding Author), LANGEM, Lab Nacl Geoquim & Mineral, Mexico City, DF, Mexico
Univ Nacl Autonoma Mexico, Inst Geol, Mexico City, DF, Mexico
LANGEM, Lab Nacl Geoquim & Mineral, Mexico City, DF, Mexico
Inst Tecnol Sonora, Dept Ciencias Agua & Medio Ambiente, Obregon, Mexico
Univ Nacl Autonoma Mexico, Inst Geol, Estn Reg Noreste, Mexico City, DF, Mexico
Univ Nacl Autonoma Mexico, Inst Ciencias Aplicadas & Tecnol, Circuito Exterior S-N,Ciudad Univ, Mexico City 04510, DF, Mexico
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