299 research outputs found

    Occurrence and fate of emerging contaminants in urban groundwater. A case study : Barcelona

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    Ensuring good water quality is becoming a major challenge in urban areas. Urban aquifers may suffer pollution from different recharge sources such as water leakage from sewer and septic systems, seepage from rivers, seawater intrusion, and losses from water supply network among others. As a result, a wide range of organic pollutants are found in urban aquifers. Since these pollutants enter the groundwater environment through the aforementioned sources, their occurrence depends on the transport mechanisms as well as the chemical and biochemical processes that occurred simultaneously. Thus, a proper assessment of groundwater quality requires an understanding of all the processes that affect these pollutants. However, the quantification of these processes is not an easy task. The aims of this thesis are to investigate the occurrence of emerging organic contaminants (EOCs) and the processes that affect them in an urban aquifer. An extensive review including the occurrence and fate of EOCs in Spanish groundwater and the evaluation of potential sources of contamination was carried out. Among organic contaminants found in groundwater, we have analysed pharmaceutically active compounds (PhACs), drugs of abuse (DAs) and personal care products in urban groundwater of Barcelona. The main sources of pollution of EOCs in urban areas are sewer leakage loss and infiltration from waste water treatment plants. Once these contaminants enter the aquifer, their concentrations are affected by numerous processes, including concentration at the source, dilution, adsorption and degradation. Many EOCs are removed from water by transformation or degradation, especially if the water has undergone a broad range of redox states. Therefore, identifying and quantifying the redox processes along a flow line is a key issue. In order to quantify such processes, we have proposed an approach using mixing ratios. The application of environmental isotopes coupled with hydrochemistry data using mixing ratios has provided the isotopic quantification of groundwater recharge sources and the occurrence of redox processes such as sulphate reduction, aerobic respiration and denitrification. The approach enabled us: (1) to quantify the mixing ratios into groundwater (2) to evaluate redox processes.Garantir una bona qualitat de l'aigua s'està convertint en un seriós problema en les zones urbanes. Els aqüífers urbans poden patir contaminació de diverses fonts de recàrrega, com fuites d'aigua de clavegueram i fosses sèptiques, filtracions des dels rius contaminats, intrusió marina, i pèrdues de la xarxa de proveïment d'aigua, entre d'altres. Per això, en els aqüífers urbans es troben diversos contaminants orgànics. La presència i evolució d'aquests contaminants als aqüífers depèn dels mecanismes de transport, així com dels processos químics i bioquímics. Per tant, una correcta avaluació de la qualitat de l'aigua subterrània requereix un enteniment de tots els processos que afecten aquests contaminants. No obstant això, la quantificació d'aquests processos no és una tasca fàcil. Els objectius d'aquesta tesi són investigar la presència de contaminants orgànics emergents (COEs) i els processos que els afecten en un aqüífer urbà. S'ha dut a terme una extensa revisió bibliogràfica de la presència de COEs en les aigües subterrànies d'Espanya, juntament amb l'avaluació de possibles fonts de contaminació. Entre els contaminants orgànics que es troben en les aigües subterrànies, s'han analitzat nombrosos fàrmacs, drogues d'abús i productes de cura personal en l'aigua subterrània urbana de Barcelona. Les principals fonts de contaminació dels COEs en zones urbanes són la pèrdua de les xarxes de clavegueram i els efluents de les estacions depuradores d'aigües residuals. Una vegada que aquests contaminants són presents a l'aqüífer, les seves concentracions es veuen afectades per nombrosos processos, incloent dilució, adsorció i degradació. Molts COEs poden ser eliminats de l'aigua subterrània per processos de transformació o degradació, especialment si l'aqüífer ha passat per diferents estats redox. Per això, la identificació i quantificació dels processos redox a l'aqüífer és una qüestió clau. Per quantificar aquests processos, s'ha proposat un mètode que utilitza les proporcions de mescla. L'aplicació dels isòtops ambientals juntament amb les dades hidroquímiques ha proporcionat la quantificació isotòpica de fonts de recàrrega d'aigua subterrània i l'ocurrència de processos redox, com la sulfato reducció, la respiració aeròbica i desnitrificació. L'ús d'aquestes metodologies ha permès: (1) quantificar les proporcions de barreja en l'aigua subterrània i (2) avaluar els processos redox.Garantizar una buena calidad del agua se está convirtiendo en un gran problema en zonas urbanas. Los acuíferos urbanos pueden sufrir contaminación a través de diversas fuentes de recarga, como fugas de agua de alcantarillado y fosas sépticas, las filtraciones desde los ríos contaminados, intrusión marina, y pérdidas de la red de abastecimiento de agua, entre otros. Por ello, en los acuíferos urbanos se encuentran numerosos contaminantes orgánicos. La presencia y evolución de estos contaminantes en los acuíferos depende de los mecanismos de transporte, así como de los procesos químicos y bioquímicos. Por lo tanto, una correcta evaluación de la calidad del agua subterránea requiere la evaluación de todos los procesos que afectan a estos contaminantes. Sin embargo, la cuantificación de estos procesos no es una tarea fácil. Los objetivos de la presente tesis son determinar la presencia de contaminantes orgánicos emergentes (COEs) y los procesos que los afectan en un acuífero urbano. Se ha llevado a cabo una extensa revisión bibliográfica de la presencia de COEs en las aguas subterráneas de España y la identificación de posibles fuentes de contaminación. Entre los contaminantes orgánicos que se encuentran en las aguas subterráneas, se han analizado numerosos fármacos, drogas de abuso y productos de cuidado personal en las aguas subterráneas urbanas de Barcelona. Las principales fuentes de contaminación de los COEs en zonas urbanas suelen ser las pérdidas de las redes de alcantarillado y los efluentes de las estaciones depuradoras de aguas residuales. Una vez que estos contaminantes están presentes en el acuífero, sus concentraciones se ven afectadas por numerosos procesos, incluyendo dilución, adsorción y degradación. Muchos COEs pueden ser eliminados del agua subterránea por procesos de transformación o degradación, especialmente si en el acuífero ha pasado por diferentes estados redox. Por ello, la identificación y cuantificación de los procesos redox en el acuífero es una cuestión clave. Para cuantificar estos procesos, se ha propuesto un método que utiliza las proporciones de mezcla. La aplicación de los isótopos ambientales junto con los datos hidroquímicos ha proporcionado la cuantificación isotópica de fuentes de recarga de agua subterránea y la ocurrencia de procesos redox, como la sulfato reducción, la respiración aeróbica y desnitrificación. El uso de estas metodologías ha permitido: (1) cuantificar las proporciones de mezcla en el agua subterránea y (2) evaluar los procesos redox

    Els espais dels serveis educatius de Pistoia: Una eina per a la inclusió

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    Curs 2013-2014Aquest treball té com a objectiu aprofundir en la importància que tenen els espais de les escoles dels Serveis Educatius de Pistoia en la inclusió i l’atenció a la diversitat. Per aquest motiu, després d’una recerca teòrica que contextualitza aquests serveis, es troba un anàlisi que relaciona els resultats d’aquesta primera part teòrica amb una segona part pràctica portada a terme durant un període de pràctiques en tres escoles d’aquests serveis educatius, una d’elles és un Asilo Nido i les altres dues són Scuole dell’infanzia.The objective of this academic work is to go into detail about the vital importance of spaces in the schools of Pistoia’s Educational Services and how it is directly connected with inclusion as well as the attention to diversity. For this reason, after an exhaustive research among these services an analysis that links this first theoretical part with a second practical part based on internships is found. These internships take part in three different schools that belong to those Educational Services. Specifically, one is an Asilo Nido and the other two are Scuole dell’infazia

    Clinical binge eating, but not uncontrolled eating, is associated with differences in executive functions: evidence from meta-analytic findings

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    Introduction: Binge eating disorder (BED) is a common psychiatric diagnosis characterized by the presence of episodes of loss of control over food consumption. Understanding the neurocognitive factors associated with binge eating pathology might help to design clinical strategies aimed at preventing or treating BED. However, results in the field are notably heterogeneous. In the current study, we aimed to establish whether binge eating behaviors (both at a clinical and at a non-clinical level) are associated with executive functions. Methods: We performed a pre-registered meta-analysis to examine the link between executive functions, BED, and uncontrolled eating, a psychobiological construct closely associated with binge eating behaviors. Articles were searched on PubMed and the main exclusion criteria were lack of information about participants' age or sex distribution or adiposity measurements, studies performed in older populations (age > 65 years old) or studies including participants with purging symptoms. Results: Relative to healthy controls, patients with BED showed lower performance in executive functions, with a small effect size. At the same time, uncontrolled eating patterns were not associated with differences in executive functions. Neither age nor body mass index (BMI) influenced these results. Conclusions: Our findings suggest that there is no association between performance in executive functions and variations along the non-clinical spectrum of binge eating behaviors. Small deficits in executive functions, however, seem to appear in individuals showing severe binge eating symptoms, that is, individuals meeting diagnostic criteria for BED. We speculate that the close links between BED and emotional distress could partly explain these results

    Allostatic load, adverse childhood experiences, executive functions, and BMI status in adolescents and young adults

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    Objectives: Chronic stress induces preclinical changes in the metabolic, cardiovascular, and immune systems. This phenomenon, known as allostatic load (AL), can impair executive functions (EF), which may be even more affected in individuals with excess weight due to their characteristic inflammatory state and cardiometabolic changes. Adverse childhood experiences (ACEs) contribute to AL and may influence executive functioning presumably via alterations within the hypothalamic-pituitary axis, including epigenetic modifications. We assess the relationship between AL and EF in youth with and without excess weight, and the effect ACEs on executive functioning. Methods: One hundred eighty-two adolescents and young adults (85 with normal weight and 97 with overweight/obesity; 10-21 years) were recruited. The estimated AL index included the following: systolic and diastolic blood pressure, glycated hemoglobin, high- and low-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein, fibrinogen, and cortisol. ACEs were measured using the Juvenile Victimization Questionnaire. The neuropsychological evaluation included the assessment of inhibition, working memory, and cognitive flexibility processes. Results: AL was not significantly associated with executive functioning, and this relationship did not depend on body-weight status. ACEs, available for 57 of 182 participants, were significantly associated with poorer executive functioning. Conclusions: Our study shows that AL is not associated with executive functioning in adolescents and young adults. Since the current sample was young, we hypothesize that a longer exposure to AL might be required for its negative effects to surface. Nevertheless, exposure to early adversity seems to be associated with poorer executive functioning in youth

    Hydrogeological impact assessment by tunnelling at sites of high sensitivity

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    A tunnel for the High Speed Train (HST) was constructed in Barcelona with an Earth Pressure Balance (EPB) Tunnel Boring Machine (TBM). The tunnel crosses Barcelona and passes under some famous landmarks such as the Sagrada Familia and the Casa Mill Both monuments are UNESCO world heritage sites and a committee appointed by the UNESCO acted as external observers during the construction. Concerns about soil settlements and the hydrogeological impacts of the construction were raised. These concerns were addressed during the design stage to forestall any unexpected events. The methodology consisted of 1) characterising the geology in detail, 2) predicting the impacts caused in the aquifer, 3) predicting the soil displacements due to water table oscillations produced by the construction, and 4) monitoring the evolution of groundwater and soil settlements. The main estimated impact on groundwater was a moderate barrier effect. The barrier effect, the magnitude of which matched the predictions, was detected during construction. The monitoring of soil settlements revealed short and long term movements. The latter movements matched the analytical predictions of soil displacements caused by the groundwater oscillations. This paper proposes a realistic procedure to estimate impacts on groundwater during tunnel construction with an EPB. Our methodology will considerably improve the construction of tunnels in urban areas. (C) 2015 Elsevier B.V. All rights reserved.Peer ReviewedPostprint (author's final draft

    Parametric assessment of hydrochemical changes associated to underground pumped hydropower storage

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    Underground pumped hydropower storage (UPHS) using abandoned mines is an alternative to store and produce electricity in flat regions. Excess of electricity is stored in form of potential energy by pumping mine water to a surface reservoir. When the demand of electricity increases, water is discharged into the mine (i.e., underground reservoir) through turbines producing electricity. During the complete operational process of UPHS plants, hydrochemical characteristics of water evolve continuously to be in equilibrium successively with the atmosphere (in the surface reservoir) and the surrounding porousmedium (in the underground reservoir). It may lead to precipitation and/or dissolution of minerals and their associated consequences, such as pH variations. Induced hydrochemical changes may have an impact on the environment and/or the efficiency (e.g., corrosions and incrustations affect facilities) of UPHS plants. The nature of the hydrochemical changes is controlled by the specific chemical characteristics of the surrounding porous medium. However, the magnitude of the changes also depends on other variables, such as hydraulic parameters. The role of these parameters is established to define screening criteria and improve the selection procedure of abandonedmines for constructing UPHS plants. This work evaluates the role of the main hydrogeological factors for three different chemical composition of the porous medium. Results are obtained by means of numerical reactive transport modeling. Potential impacts on the environment (mainly on groundwater and surface water bodies) and on the efficiency of the UPHS plants vary considerably from a hydraulic parameter to another showing the need for a detailed characterization before choosing locations of future UPHS plants.SMARTWATE

    Underground Excavations Below the Water Table by the Cut-and-Cover Method

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    Most underground constructions, which are needed to improve mobility and increase available space in urban areas, require excavations that are usually deeper than the water table (e.g., for the construction of stations or underground parking lots). A frequently used technique to develop excavations under these conditions consists in combining the cut-and-cover method with a dewatering system based on deep pumping wells. Retaining walls used for the cut-and-cover method allow excavating between vertical walls and minimizes the inflow of groundwater, while deep pumping wells provide dry and stable conditions. Despite this technique is widely used, some aspects related with the presence of groundwater must be considered to avoid accidents. Dewatering systems must be properly designed to guarantee suitable conditions and to minimize the pumping settlements outside of the working area. In addition, it is required to assess the presence of defects in the retaining walls because the flow of groundwater through them may entail negative consequences. This chapter explains procedures (i) to design efficient dewatering systems considering the working conditions, the stability and the impacts generated in the vicinity of the construction, and (ii) to evaluate the state of the retaining walls by using hydrogeological tools

    Lung Extracellular Matrix Hydrogels-Derived Vesicles Contribute to Epithelial Lung Repair

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    The use of physiomimetic decellularized extracellular matrix-derived hydrogels is attracting interest since they can modulate the therapeutic capacity of numerous cell types, including mesenchymal stromal cells (MSCs). Remarkably, extracellular vesicles (EVs) derived from MSCs display similar functions as their parental cells, mitigating tissue damage in lung diseases. However, recent data have shown that ECM-derived hydrogels could release other resident vesicles similar to EVs. Here, we aim to better understand the contribution of EVs and ECM-vesicles released from MSCs and/or lung-derived hydrogel (L-HG) in lung repair by using an in vitro lung injury model. L-HG derived-vesicles and MSCs EVs cultured either in L-HG or conventional plates were isolated and characterized. The therapeutic capacity of vesicles obtained from each experimental condition was tested by using an alveolar epithelial wound-healing assay. The number of ECM-vesicles released from acellular L-HG was 10-fold greater than EVs from conventional MSCs cell culture revealing that L-HG is an important source of bioactive vesicles. MSCs-derived EVs and L-HG vesicles have similar therapeutic capacity in lung repair. However, when wound closure rate was normalized by total proteins, the MSCs-derived EVs shows higher therapeutic potential to those released by L-HG. The EVs released from L-HG must be considered when HG is used as substrate for cell culture and EVs isolation
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