Browsing by Author "Urdiales, C."

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    Evaluation of sulfate rhizofiltration by Carpobrotus chilensis for treating mining waters
    (2024) Tapia, Y.; Salazar, O.; Joven, A.; Castillo, B.; Urdiales, C.; Garcia, A.; Ihle, C.; Acuna, E.
    Chile, the world's leading copper producer, generates significant volumes of mining waters, some of which cannot be recirculated into the production process. These mining waters are characterized by elevated sulfate (SO42-) concentrations, requiring sustainable management strategies for potential reuse. This study aims to evaluate the rhizofiltration technique using Carpobrotus chilensis for treating mining waters with a high SO(4)(2- )concentration. Initially, the mining waters exhibited a pH of 7.97 +/- 0.16 and a SO42- concentration of 2,743 +/- 137 mg L-1, while the control water had a pH of 7.88 +/- 0.08 and a SO42- concentration of 775 +/- 19.0 mg L-1. The plants were hydroponically cultivated in 40 L containers with mining waters and drinking water as a control. Over an 8-week period, the pH of the mining water decreased to 3.12 +/- 0.01, and the SO42- concentration declined to 2,200 +/- 110 mg L-1. Notably, the fresh weight of roots was significantly higher in plants grown in mining water (22.2 +/- 6.66 g) compared to those in the control treatment (14.3 +/- 4.28 g). However, an undesirable increase in the acidity was observed in the mining waters after rhizofiltration, which was attributed to hydrogen sulfate (HSO4-) and/or root exudates. Despite the unexpected increase in acidity, C. chilensis effectively reduced the concentration of SO42- in mining waters by 20%. Additionally, the C. chilensis roots accumulated 4.84 +/- 1.40% of sulfur (S), a level comparable to thiophore plants. This study provides evidence that this non-aquatic plant can be used in sulfate rhizofiltration. NOVELTY STATEMENT Caprobrotus chilensis is a good candidate for sulfate rhizolfiltration in mining waters. The accumulation of sulfur by the roots of Carpobrotus chilensis reached 4.84% Mining waters with a high concentration of sulfates require control of the redox potential
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    Transport Mechanisms of the Anthropogenic Contaminant Sulfamethoxazole in Volcanic Ash Soils Evaluated Using the Hydrus-1d Model
    (2024) Urdiales, C.; Urdiales Flores, D.; Tapia, Y.; Caceres Jensen, L.; Šimůnek, J.; Antilén Lizana, Mónica
    The volcanic soils in Chile, where a significant portion of agricultural activities take place, are impacted by the presence of veterinary drugs, including sulfamethoxazole (SMX). The transport of SMX in soils Collipulli (CLL), Frutillar (FRU), Nueva Braunau (NBR), and Osorno (OSR) was explored. Aadsorption batch, kinetics, and column breakthrough curve (BTC) experiments were conducted, alongside transport modelling. The adsorption kinetics of SMX in CLL soil followed a pseudo-first-order (PPO) model, while FRU, NBR, and OSR soils aligned with a pseudo-second-order (PSO) model. Freundlich isotherms effectively described SMX adsorption in CLL and OSR soils, indicating multilayer adsorption, while Langmuir isotherms fit the FRU and NBR soils, suggesting monolayer adsorption. Using HYDRUS-1D software, we simulated SMX transport in soil columns. BTCs were best modelled using a two-site sorption model with both equilibrium and kinetic adsorption. SMX was more mobile in CLL soil, due to its lower organic matter (OM) content and adsorption capacity, while FRU, NBR, and OSR soils showed slower transport, reflecting higher OM content and greater adsorption capacity, reducing SMX leaching. These findings emphasize the importance of soil properties, such as OM content, in influencing SMX behavior, and are vital for assessing environmental impacts and developing mitigation strategies.