Remediación agua contaminada por mercurio y portlandita en Flix

Hace unos años se decidió descontaminar el embalse de Flix, afectado por vertidos de residuos por un empresa química durante todo el siglo pasado. •Los residuos formaron 4 lóbulos de sedimentos en el río, con elevadas concentraciones de Mercurio, compuestos orgánicos volátiles (COV´s), residuos de producción de acetileno (Ca(OH)2) y pesticidas organoclorados. •Se ha realizado un modelo 0D de transporte reactivo de la concentración en el agua conforme se excavan los sedimentos transitorio y explícito en excel, calibrado hasta Septiembre 2014 con datos semanales de la empresa extractora FCC. •El modelo concluía dos graves problemas al terminar la excavación: Elevada concentración de Hg y pH (12.4), equilibrado con portlandita •Desde Marzo de 2015 se observó un acusado descenso de pH y Hg. Nuestro objetivo ha sido encontrar la causa de estos descensos, para ello se han realizado simulaciones, muestreos y experimentos de laboratorio. La precipitación CaCO3 debida a la difusión de CO2 atmosférico explica una parte de la disminución de pH, pero resulta insuficiente aun considerando la oxidación de materia orgánica. •El Hg se adsorbido en CaCO3 es alrededor de un 30%, otro 60% parece haberse volatilizado. •La electrolisis en laboratorio reproduce un descenso del Hg de 80% en 3 días. Sólo un 10% de Hg ha sido recuperado en el cátodo. • Se cree que el Hg2+ se reduce a Hg0 y volatiliza. •El pH descendió hasta 3.8, se cree que debido a hidrólisis del agua. •Se esta trabajando en comprobar el Hg0 volatilizado en próximos experimentos.Postprint (published version

Tracer test modeling for characterizing heterogeneity and local-scale residence time distribution in an artificial recharge site

Artificial recharge of aquifers is a technique for improving water quality and increasing groundwater resources. Understanding the fate of a potential contaminant requires knowledge of the residence time distribution (RTD) of the recharged water in the aquifer beneath. A simple way to obtain the RTDs is to perform a tracer test. We performed a pulse injection tracer test in an artificial recharge system through an infiltration basin to obtain the breakthrough curves, which directly yield the RTDs. The RTDs turned out to be very broad and we used a numerical model to interpret them, to characterize heterogeneity, and to extend the model to other flow conditions. The model comprised nine layers at the site scaled to emulate the layering of aquifer deposits. Two types of hypotheses were considered: homogeneous (all flow and transport parameters identical for every layer) and heterogeneous (diverse parameters for each layer). The parameters were calibrated against the head and concentration data in both model types, which were validated quite satisfactorily against 1,1,2-Trichloroethane and electrical conductivity data collected over a long period of time with highly varying flow conditions. We found that the broad RTDs can be attributed to the complex flow structure generated under the basin due to three-dimensionality and time fluctuations (the homogeneous model produced broad RTDs) and the heterogeneity of the media (the heterogeneous model yielded much better fits). We conclude that heterogeneity must be acknowledged to properly assess mixing and broad RTDs, which are required to explain the water quality improvement of artificial recharge basins.Peer ReviewedPostprint (published version

Salinity is reduced below the evaporation front during soil salinization

La salinización de suelos es un problema global. Generalmente, la salinización es causada por el transporte de sales hacia la superficie por capilaridad y, a pesar de su importancia global, los mecanismos que la controlan aún no están bien descritos (Kampf et al., 2005). En este trabajo, se han llevado a cabo experimentos de laboratorio y simulaciones numéricas que muestran que las sales precipitan en el frente de evaporación, el cual se da en una zona estrecha del suelo y que el flujo de vapor de agua se desplaza, no solo en sentido ascendente, sino también descendente, desde dicho frente de evaporación. El flujo de vapor descendente, condensa, causando la dilución de la solución. Esto implica, que contrariamente a lo creído hasta ahora, la salinización (Xu y Shao, 2002) (la precipitación de sales) no se da por debajo del frente de evaporación. Soil salinzation is a global problem. Salinization is generally caused by salts transported to the soil surface by capillary rising water. Despite its global importance, actual salinization mechanisms are poorly understood (Kampf et al., 2005). We use laboratory experiments and numerical models to show that salt precipitates at the evaporation front, which occurs within a very narrow band. Part of the evaporating water diffuses downwards, where it condensates. This implies that, contrary to widely spread belief, salinization (Xu & Shao, 2002) (i.e. salt precipitation) does not occur below the evaporation front. Instead, the upflowing solution becomes diluted.Peer ReviewedPostprint (published version

How does neighbourhood socio-economic status affect the interrelationships between functioning dimensions in first episode of psychosis? A network analysis approach

The links between psychosis and socio-economic disadvantage have been widely studied. No previous study has analysed the interrelationships and mutual influences between functioning dimensions in first episode of psychosis (FEP) according to their neighbourhood household income, using a multidimensional and transdiagnostic perspective. 170 patients and 129 controls, participants in an observational study (AGES-CM), comprised the study sample. The WHO Disability Assessment Schedule (WHODAS 2.0) was used to assess functioning, whereas participants' postcodes were used to obtain the average household income for each neighbourhood, collected by the Spanish National Statistics Institute (INE). Network analyses were conducted with the aim of defining the interrelationships between the different dimensions of functioning according to the neighbourhood household income. Our results show that lower neighbourhood socioeconomic level is associated with lower functioning in patients with FEP. Moreover, our findings suggest that “household responsibilities” plays a central role in the disability of patients who live in low-income neighbourhoods, whereas “dealing with strangers” is the most important node in the network of patients who live in high-income neighbourhoods. These results could help to personalize treatments, by allowing the identification of potential functioning areas to be prioritized in the treatment of FEP according to the patient's neighbourhood characteristic

The interplay between functioning problems and symptoms in first episode of psychosis: an approach from network analysis

The relationship between psychotic symptoms and global measures of functioning has been widely studied. No previous study has assessed so far the interplay between specific clinical symptoms and particular areas of functioning in first-episode psychosis (FEP) using network analysis methods. A total of 191 patients with FEP (age 24.45 ± 6.28 years, 64.9% male) participating in an observational and longitudinal study (AGES-CM) comprised the study sample. Functioning problems were assessed with the WHO Disability Assessment Schedule (WHODAS), whereas the Positive and Negative Syndrome Scale (PANSS) was used to assess symptom severity. Network analysis were conducted with the aim of analysing the patterns of relationships between the different dimensions of functioning and PANSS symptoms and factors at baseline. According to our results, the most important nodes were “conceptual disorganization”, “emotional withdrawal”, “lack of spontaneity and flow of conversation”, “delusions”, “unusual thought content”, “dealing with strangers” and “poor rapport”. Our findings suggest that these symptoms and functioning dimensions should be prioritized in the clinical assessment and management of patients with FEP. These areas may also become targets of future early intervention strategies, so as to improve quality of life in this populationThis work was supported by the Madrid Regional Government (R&D activities in Biomedicine (grant number S2017/BMD-3740 - AGES-CM 2-CM)) and Structural Funds of the European Union. Ana Izquierdo’s work is supported by the PFIS predoctoral program (FI17/00138) from the Instituto de Salud Carlos III (Spain) and co-funded by the European Union (ERDF/ESF, "A way to make Europe”/ “Investing in your future”) and The Biomedical Research Foundation of La Princesa University Hospital. Angela Ib´a˜nez thanks the support of CIBERSAM and of the Spanish Ministry of Science, Innovation and Universities. Instituto de Salud Carlos III (PI16/00834 and PI19/01295) co-financed by ERDF Funds from the European Commission. Covadonga M. Díaz-Caneja holds a Juan Rod´es Grant from Instituto de Salud Carlos III (JR19/00024). Celso Arango was supported by the Spanish Ministry of Science and Innovation. Instituto de Salud Carlos III (SAM16PE07CP1, PI16/02012, PI19/ 024), co-financed by ERDF Funds from the European Commission, “A way of making Europe”, CIBERSAM. Madrid Regional Government (B2017/BMD-3740 AGES-CM-2), European Union Structural Funds. European Union Seventh Framework Program under grant agreements FP7-4-HEALTH-2009-2.2.1-2-241909 (Project EU-GEI), FP7- HEALTH- 2013-2.2.1-2-603196 (Project PSYSCAN) and FP7- HEALTH-2013- 2.2.1-2-602478 (Project METSY); and European Union H2020 Program under the Innovative Medicines Initiative 2 Joint Undertaking (grant agreement No 115916, Project PRISM, and grant agreement No 777394, Project AIMS-2-TRIALS), Fundaci´on Familia Alonso, Fundaci´on Alicia Koplowitz and Fundaci´on Mutua Madrile˜n

Fluid inclusions composition in halite from Biurrún borehole (Navarra Potash basin)

The solute concentration of fluid inclusions in halite samples have been analyzed by X-Ray microanalysis (Cryo-SEM-EDS). The results together with the mineral sequence are useful to describe the evolution of the Priabonian basin of Navarra. Thus, a lower salt unit (sal de muro) formed in a restricted basin with seawater recharge. Later, the basin closed to sea and evolved with decreasing volume and stratified brine to the deposition of potash salts. Finally, an upper salt unit (sal d e techo) formed in a continental lake without seawater influenc

Radionuclide migration: coupling transport and chemistry

Postprint (published version

Remediación agua contaminada por mercurio y portlandita en Flix

Hace unos años se decidió descontaminar el embalse de Flix, afectado por vertidos de residuos por un empresa química durante todo el siglo pasado. •Los residuos formaron 4 lóbulos de sedimentos en el río, con elevadas concentraciones de Mercurio, compuestos orgánicos volátiles (COV´s), residuos de producción de acetileno (Ca(OH)2) y pesticidas organoclorados. •Se ha realizado un modelo 0D de transporte reactivo de la concentración en el agua conforme se excavan los sedimentos transitorio y explícito en excel, calibrado hasta Septiembre 2014 con datos semanales de la empresa extractora FCC. •El modelo concluía dos graves problemas al terminar la excavación: Elevada concentración de Hg y pH (12.4), equilibrado con portlandita •Desde Marzo de 2015 se observó un acusado descenso de pH y Hg. Nuestro objetivo ha sido encontrar la causa de estos descensos, para ello se han realizado simulaciones, muestreos y experimentos de laboratorio. La precipitación CaCO3 debida a la difusión de CO2 atmosférico explica una parte de la disminución de pH, pero resulta insuficiente aun considerando la oxidación de materia orgánica. •El Hg se adsorbido en CaCO3 es alrededor de un 30%, otro 60% parece haberse volatilizado. •La electrolisis en laboratorio reproduce un descenso del Hg de 80% en 3 días. Sólo un 10% de Hg ha sido recuperado en el cátodo. • Se cree que el Hg2+ se reduce a Hg0 y volatiliza. •El pH descendió hasta 3.8, se cree que debido a hidrólisis del agua. •Se esta trabajando en comprobar el Hg0 volatilizado en próximos experimentos