RT journal article
T1 Fractionation of U and heavy metals into the colloidal fraction in acid mine drainage conditions in the Río Tinto area (SW Spain)
A1 Curcio, Andrea Celeste
A1 Barbero González, Luis Carlos
A1 Casas Ruiz, Melquiades
A1 López Ramírez, Juan Antonio
A2 Biología
A2 Ciencias de la Tierra
A2 Física Aplicada
A2 Tecnologías del Medio Ambiente
K1 Acid mine drainage
K1 Colloidal particles
K1 Uranium
K1 Heavy metals
K1 Ultrafiltration
K1 Permeation model
AB The Río Tinto mining area provides ideal conditions for studying the role of colloidal particles in concentrating. All the elements are present in higher concentrations respect to their content in common natural waters. 234U/238U activity ratio ranges between 2.286 ± 0.149 and 2.531 ± 0.151. Concentration of Fe and Al are in the order of 104–103 mg/L; Co, Zn and Cu values are three times lower than Fe and Al, but still much greater than in natural waters; U reaches values up to 40.73 μg/L. To evaluate the partitioning of these elements into the colloidal fraction, ultrafiltration (UF) experiments were made. A permeation model describing the relationship between concentration of the elements or isotopes in the permeate solution and the concentration factor (CF) was calculated. Experiments were carried out using CF from 1.5 to 25.0. The behaviour of investigated heavy metals and U can be predicted by a permeation model that provides similar permeation coefficient (Pc) for all of them (Pc = 0.95–0.97 for 50 kDa, Pc = 0.86–0.88 for 10 kDa, and Pc = 0.80–0.86 for 3 kDa). Retention for all the investigated elements occurs, resulting in up to 23% of the element associated to the 3 kDa colloidal fraction. The increase in U and heavy metals concentrations in the retentate fraction with the increasing CF is due to the retention of the colloidal fraction. The colloidal abundance of related metals increased with decreasing mem- brane MWCO even though the difference is small between 3 and 10kDa fraction for some metals Characterization of colloidal material is needed to better understand the state of play in this context.
PB Elsevier
SN 01697722
YR 2019
FD 2019-04
LK http://hdl.handle.net/10498/30501
UL http://hdl.handle.net/10498/30501
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 07-nov-2026