Amendment application in a multicontaminated mine soil: Effects on trace element mobility

The final publication is available at Springer via http://dx.doi.org/10.1007/s11270-014-1874-4Several amendments were tested for their effectiveness in aiding plant growth and immobilising contaminants in pots containing soil from an arsenopyrite mine contaminated with arsenic and heavy metals. Trace element solubility in pore water was monitored using Rhizon samplers for five weeks. Results showed that amendments containing ferrous sulphate and ferrous sulphate combined with paper mill limited arsenic mobilisation and increased metal solubility. However, ferrous sulphate in combination with calcium carbonate was effective in reducing arsenic and metal solubilisation. Plant biomass of both the grass species used during the experiment, Arrhenatherum elatius and Festuca curvifolia, was a sensitive indicator of the comparative efficiency of the amendments, although metal(loid)s concentration in pore water did not correlate with plant uptakeThis study was supported by the Spanish Ministry of Science and Innovation, project COMFITES CTM2010-21922-C02-02; and by the Comunidad de Madrid, project EIADES S2009/AMB-147

The fate of arsenic in soil-plant systems

The final publication is available at Springer via http://dx.doi.org/10.1007/978-1-4614-1463-6_1Arsenic (As) is an element belonging to the group V-A, and it demonstrates characteristics of a metalloid. Because arsenic more easily forms anions, its non-metal properties dominate. When arsenic is in an oxidation state of +5, it acts similar to phosphorus, a fact that has many implications for the way in which it reacts in soil, as well as its potential toxicity in plants. The most common oxidation states of As are -3, 0, +3, and +5. Arsines and metal arsines are those in which As has an oxidation state of -3, and these forms are very unstable under oxidizing conditions. Under aerobic conditions, the oxidation state of As tends to be +5, and when this occurs at a pH between 2 and 3, arsenic acid (H3AsO4) is formed. When the pH rises to values between 3 and 11, this compound disassociates to H2AsO4 - and HAsO4 2- (Smedley and Kinninburgh 2002). Under anaerobic conditions, the predominant As species is H3AsO3This study was supported by the Spanish Ministry of Education and Science, project CTM 2010-21922-CO2-02, and by Comunidad de Madrid, project S2009/AMB- 147

The fate of arsenic in soils adjacent to an old mine site (Bustarviejo, Spain): Mobility and transfer to native flora

The final publication is available at Springer via http://dx.doi.org/10.1007/s11368-009-0099-4Background, aim, and scope The mobility of arsenic in soils and its transfer to other environmental components present significant environmental risks. The management of polluted land is determined by the availability, mobility, and transfer of inorganic pollutants to different ecosystem compartments. In this paper, the fate of arsenic at this mining site has been evaluated to determine future management practises to minimise such risk. Materials and methods In a field study carried out in the area adjacent to a mining site at Bustarviejo (North Madrid, Spain), samples of soils, plants, and water were collected from areas adjacent to the core of the former mining activity. The following parameters were investigated in soil samples: pH, organic matter, pseudo-total As, P, and Fe, and labile As and P, and a sequential extraction procedure was performed to investigate As speciation in soil. Plant materials were analysed for both As and P. Arsenic concentrations in water samples (surface and soil pore water collected in the field) were also measured. Results are considered in tandem with previous data on metal concentrations in soils and plants from this site. Results Despite high As concentrations in soils impacted by former mining activities (spoil accumulation and drainage from spoil heaps resulted in concentrations of up to 3,000 mg kg-1), it was not present in a labile form. Sequential extraction revealed that arsenic was mainly retained by Al- and Fe-(oxihydr)oxides (up to 80%). Therefore, only a small proportion of the total soil pool was potentially available for plant uptake (0.3% and 7% extracted by (NH4)2SO4 and NH4H2PO4, respectively). There was very limited transfer of arsenic from soil to plants, and concentrations of arsenic in shoot tissues were relatively low (<8 μg g-1). There was no evidence of phytotoxic effects in the flora that had colonised this site, indicating that a sustainable ecosystem had been established. Discussion High levels of arsenic occur at this site, but arsenic mobility appears to be primarily controlled by the presence of amorphous and crystalline Fe and Al hydrous oxides. Although a low labile As fraction was extracted, concentrations of arsenic in both surface and soil pore water are of concern. The risk of arsenic remobilisation by plant uptake or transfer to the food chain via plant consumption is relatively low in these soils. Large amounts of metals and arsenic remain at the site, and potential risks need to be monitored. Some possible remediation strategies that take into account the presence of both arsenic and heavy metals will be suggested. Recommendations Natural attenuation and phytostabilisation processes are taking place in several parts of the study area. These natural processes could be enhanced by application of both compost and a suitable Fe-based amendment. This augmentation of the re-vegetation of the affected area could act to promote both arsenic and metal stabilisation in mine tailings with additional benefits for further vegetation establishmentThis study was supported by the Spanish Ministry of Education and Science, project CTM 2007-66401-CO2/TECNO, and by Comunidad de Madrid, project S-0505/AMB/0296. The authors are grateful to the Excmo. Ayuntamiento de Bustarviejo, for admittance to the mine zone and the facilities offered and to Dr. R. Gamarra for his assistance with plant identification. Authors are grateful to L. Beesley for his comments and language corrections

Simuladores de conducción urbanos: una técnica de optimización de bases de datos visuales utilizando aspectos perceptivos

El objetivo del presente artículo es exponer una técnica de optimización de entornos virtuales urbanos, los cuales constituyen bases de datos visuales orientadas a su utilización en simuladores de conducción. La base de la técnica se fundamenta en la identificación de aquellos factores que intervienen en el diseño constructivo del escenario virtual, determinando si son estadísticamente significativos en localidad y en el grado de realismo percibidos por el usuario del simulador gráfico. Este planteamiento supone una nueva vía de simplificación de este tipo de escenarios complejos ya que permite decidir la combinación óptima de modificaciones en las geometrías de los modelos, de tal forma que la base de datos visual resultante se comporte adecuadamente en tiempo real sin comprometerla latencia de la simulación y mostrando al mismo tiempo al usuario final un escenario totalmente reconocible e inmersivo. Se establece un modelo estadístico basado en el diseño de experimentos donde se estudia el efecto que, sobre cada una de las variables respuestas elegidas, tienen el conjunto de factores de diseño del escenario virtual. El modelo ha sido validado experimentalmente en un escenario virtual implementado en un simulador de conducción de bajo coste. La ventaja fundamental de esta contribución es la asignación selectiva de los recursos necesarios a la hora de modelar las geometrías del escenario, permitiendo la reducción de costes y tiempos de desarrollo durante el proceso de generación 3D

Amendment application in a multi-contaminated mine soil: Effects on soil enzymatic activities and ecotoxicological characteristics

The final publication is available at Springer via http://dx.doi.org/10.1007/s11356-013-2412-4Several amendments were tested on soils obtained from an arsenopyrite mine, further planted with Arrhenatherum elatius and Festuca curvifolia, in order to assess their ability to improve soil's ecotoxicological characteristics. The properties used to assess the effects were: soil enzymatic activities (dehydrogenase, β-glucosidase, acid phosphatase, urease, protease and cellulase), terrestrial bioassays (Eisenia fetida mortality and avoidance behaviour), and aquatic bioassays using a soil leachate (Daphnia magna immobilisation and Vibrio fischeri bioluminescence inhibition). The treatment with FeSO4 1 % w/w was able to reduce extractable As in soil, but increased the extractable Cu, Mn and Zn concentrations, as a consequence of the decrease in soil pH, in relation to the unamended soil, from 5.0 to 3.4, respectively. As a consequence, this treatment had a detrimental effect in some of the soil enzymatic activities (e.g. dehydrogenase, acid phosphatase, urease and cellulase), did not allow plant growth, induced E. fetida mortality in the highest concentration tested (100 % w/w), and its soil leachate was very toxic towards D. magna and V. fischeri. The combined application of FeSO4 1 % w/w with other treatments (e.g. CaCO3 1 % w/w and paper mill 1 % w/w) allowed a decrease in extractable As and metals, and a soil pH value closer to neutrality. As a consequence, dehydrogenase activity, plant growth and some of the bioassays identified those as better soil treatments to this type of multi-contaminated soi

The potential of arbuscular mycorrhizal fungi to enhance metallic micronutrient uptake and mitigate food contamination in agriculture: prospects and challenges

Optimizing agroecosystems and crops for micronutrient uptake while reducing issues with inorganic contaminants (metal(loid)s) is a challenging task. One promising approach is to use arbuscular mycorrhizal fungi (AMF) and investigate the physiological, molecular and epigenetic changes that occur in their presence and that lead to changes in plant metal(loid) concentration (biofortification of micronutrients or mitigation of contaminants). Moreover, it is important to understand these mechanisms in the context of the soil microbiome, particularly those interactions of AMF with other soil microbes that can further shape crop nutrition. To address these challenges, a two-pronged approach is recommended: exploring molecular mechanisms and investigating microbiome management and engineering. Combining both approaches can lead to benefits in human health by balancing nutrition and contamination caused by metal(loid)s in the agro-ecosystemThis work was supported by grant PID2021-1255210B-I00 funded by MCIN/AEI/10.13039/ 501100011033 and by ‘ERDF A way of making Europe’, by the ‘European Union’. NC is a University of Ottawa Research Chair in Microbial Genomics, and his research on AMF genetics and genomics is supported by the Discovery Program of the Natural Sciences and Engineering Research Council (RGPIN2020-05643) and a Discovery Accelerator Supplements Program (RGPAS2020-00033

Risk assessment of an abandoned pyrite mine in Spain based on direct toxicity assays

This is the author’s version of a work that was accepted for publication in Science of the Total Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in [SCIENCE OF THE TOTAL ENVIRONMENT 470-471 (2014)] http://dx.doi.org/10.1016/j.scitotenv.2013.09.101This research reports the risk assessment of an abandoned pyrite mine using direct toxicity assays of soil and groundwater samples taken at the site. The toxicity of As and heavy metals from mining soils to soil and aquatic organisms was studied using the Multispecies Soil System (MS-3) in soil columns. Ecotoxicological assessment was performed with soil samples diluted with a control soil at concentrations of 12.5, 25, 50 and 100% test soil/ soil (w/w). In this way, changes in the mobility and bioavailability of soil contaminants due to changes in geochemical soil properties via soil dilution were studied. The toxicity of water samples was tested on algae and Daphnia magna. The assessment of the mining area indicated that the current presence of As and heavy metals at the site may cause injuries to soil and aquatic organisms in the entire research area. Moreover, this investigation demonstrated that changes in geochemical conditions can increase the availability of arsenic and, consequently, the environmental risk of these soils. A good correlation was not found between toxicity parameters and the concentrations of soil contaminants based on total and extracted element concentrations. This finding reinforces the usefulness of direct toxicity assays for evaluating environmental riskThis work has been financed by the Community of Madrid through EIADES Project S-2009/AMB/1478 and by the Spanish Ministry of Education and Science, project CTM-2007-66401-CO2/ TECNO and CTM2010-21922-C02-0

Notas sobre la arquitectura de la regulación, supervisión y estabilidad financiera en Europa

Artículo de revistaLa reforma de la arquitectura de la regulación, supervisión y estabilidad financiera en Europa, aprobada por el Consejo ECOFIN el pasado diciembre, tiene por objetivo solventar los problemas de los que tradicionalmente adolecía el proceso de elaboración de normativa financiera en la Unión Europea: lentitud, falta de flexibilidad y de eficiencia para hacer frente a los rápidos cambios que tienen lugar en el sector financiero. Esta reforma consagra un modelo sectorial y descentralizado, en el que se refuerzan los mecanismos de cooperación entre los reguladores de bancos, valores y seguros de los Estados miembros, además de reconocerse las especificidades de los conglomerados financieros. Esta nueva arquitectura no supone una transferencia de competencias desde el ámbito nacional al comunitario, y es considerada neutral respecto a los distintos modelos de organización institucional de la supervisión existentes actualmente en los Estados miembros de la Unión Europea

Natural attenuation of residual heavy metal contamination in soils affected by the Aznalcóllar mine spill

NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Environmental Management. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Environmental Management 92.8 (2011): 2069-2075 http://dx.doi.org/10.1016/j.jenvman.2011.03.030Non-amended soils affected by pyritic sludge residues were monitored for 7 years to assess the long-term natural attenuation ability of these soils. The decrease in both the total concentration of elements (particularly As) and (NH4)2SO4-extractable fractions of Mn, Cu, Zn, and Cd below maximum permissible levels indicate a successful natural ability to attenuate soil pollution. Soil acidification by pyrite oxidation and rainfall-enhanced leaching were the largest contributors to the reduction of high (Mn, Cu, Zn and Cd) and low (Fe, Al, and As) availability metals. Periodic use of correlation and spatial distribution analysis was useful in monitoring elemental dispersion and soil property/element relationshipsFinancial support from the Spanish MICINN (CTM 2007-66401-CO2-02/TECNO; CTM 2004-06715-CO2-01), and from Comunidad de Madrid (EIADES S2009/AMB-1478) is acknowledge

Mathematical questionnaires through the virtual platform

Las plataformas virtuales permiten realizar numerosas innovaciones docentes, algunas de ellas orientadas a la consolidación de conceptos. Partiendo de las herramientas disponibles en la plataforma virtual WebCT, hemos seleccionado la herramienta “Evaluación” para crear un cuestionario sobre la asignatura Matemáticas II del Grado en Administración y Dirección de Empresas. Se ha planteado de forma que permita al alumno recordar y consolidar aquellos conceptos matemáticos previos que resultan indispensables para la teoría de Optimización que se imparte en esta asignatura, y facilite el desarrollo de sus competencias específicas junto a otras capacidades tales como el autoaprendizaje y la autoevaluación.Virtual platforms allow for numerous teaching innovations, some of them aimed at consolidation of concepts. Based on the tools available on the virtual platform WebCT, we have selected the tool called "evaluation" to create a questionnaire on the course Mathematics II for Business Administration and Management. It has been proposed to allow the student to remember those mathematical basic concepts that are necessary for optimization theory that is taught in this course, and facilitate the development of specific skills of the subject along with other abilities such as self- instruction and self-evaluation