Examinando por Autor "Mosqueda, Fernando"
Mostrando 1 - 3 de 3
- Resultados por página
- Opciones de ordenación
Ítem Hydrochemical behaviour of long-lived natural radionuclides in Spanish groundwaters(Elsevier, 2020-08-01) Pérez-Moreno, Silvia María; Guerrero, José Luis; Mosqueda, Fernando; Gázquez, Manuel Jesús; Bolívar, Juan PedroThis research was focused on the analyses of the hydrochemical behaviour of long-lived natural radionuclides (210Po, 210Pb, 234,238U, 230,232Th, 226,228Ra) in groundwaters from Spanish aquifers with different geological characteristics and the evaluation of the dose by ingestion of these waters. The study was performed by the gross alpha-beta, alpha spectrometry and physicochemical analysis of a set of bottled drinking waters. Radionuclide activities in the investigated aquifers were highly variable. High concentration of 210Pb is associated with granitic bedrock and reducing conditions. On the other hand, the highest 238,234U concentrations were found in carbonate aquifers. Activities of 226Ra are largely controlled by ion exchange reactions due to the presence of relatively high concentration of chloride. Several waters exceeded the parametric value for gross alpha mainly due to 234U, 226Ra and/or 210Pb concentrations. Moreover, the content of 226Ra and 210Pb in the water contributed mainly to the indicative dose.Ítem Pollution evaluation on the salt-marshes under the phosphogypsum stacks of Huelva due to deep leachates(Elsevier, 2019-09-01) Guerrero, José Luis; Gutiérrez-Alvarez, Isidoro; Mosqueda, Fernando; Olías, Manuel; García-Tenorio, RafaelIn the salth-marshes of the Tinto River (Huelva estuary, SW Spain), are stored in stacks around 100Mt of PG, covering a surface of 1000 ha without any type of isolation, which produce an important impact in the surrounding environment. On the other hand, this ecosystem it is affected by acid mine drainage (AMD) from sulphide mines located upstream the Tinto River. The aim of this study is to evaluate the deep pollution of the underlain salt-marsh sediments due to leachates from the PG stacks. For that purpose, 7 cores were collected from zones 2 and 3 of the stacks, and PG and salt-marsh sediments samples from different depths were analyzed. The physicochemicalparameters, mineralogy, granulometry and the concentration of the main elements of interest were determined in the samples. Most analysed salt-marsh sediments are not affected by PG stacks pollution, because sediments act as a “barrier” for the leachates from the PG, concentrating the contaminants in the first decimetres (0.5 m) under PG-sediments contact, and the deep infiltration is very limited. The obtained results suggest that the perimeter channel which is projected to build in the restauration project, should has a depth of 1m below the level of the PG stacks for assuring the complete collection of leachates from the stacks, and avoid their liberation into the Tinto River estuary.Ítem Utilization of phosphogypsum and red mud in alfalfa cultivation(Elsevier, 2024-03-26) Palencia, Pedro; Guerrero, José Luis; Millán, Rebeca; Mosqueda, Fernando; Bolívar, Juan PedroIn this work, the utilization of phosphogypsum (PG), a waste coming from the manufacture of phosphate fertilizers, as fertilizer for alfalfa (Medicago sativa L.) crops was investigated using pot experiments. The objective of this study was to evaluate the effects of both phosphogypsum and red mud (RM) in two soils representative of the pasture production area in Southern Spain. The morpho-physiological parameters of biomass, plant height, number of stems and number of leaves, as well as the chemical parameters of soil content, were measured. High doses of PG inhibited seed germination in some treatments. In addition, the treatment substrate (2550 g soil + 50 g kg−1 PG + 100 g kg−1 RM) also affected seed germination, possibly due to the large amount of RM. The application of PG and RM to the soil increased the availability of important nutrients for alfalfa, such as phosphorus (P), calcium (Ca2+) and magnesium (Mg2+). The results demonstrate that the treatment with PG significantly improved the uptake of P in alfalfa.