26 research outputs found

    Nitrate pollution of groundwater, all right... but nothing else?

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    Contamination from agricultural sources and, in particular, nitrate pollution, is one of the main concerns in groundwater management. However, this type of pollution entails the entrance of other substances into the aquifer, as well as it may promote other processes. In this study, we deal with hydrochemical and isotopic analysis of groundwater samples from four distinct zones in Catalonia (NE Spain), which include different lithological units, to investigate the influence of manure fertilization on the overall hydrochemical composition of groundwater. Results indicate that high nitrate concentrations, resulting from intense manure application, homogenize the contents of the major dissolved ions (i.e.; Cl-, SO42-, Ca2+, Na+, K+, and Mg2+). Moreover, positive linear relationships between nitrate and some ions are found indicating the magnitude of the fertilization impact on groundwater hydrochemistry. Nevertheless, the increasing concentration of specific ions is not only attributed to the manure input, but to the enhancing effect of manure and slurry upon the biogeochemical processes that control water-rock interactions. Such results raise awareness that such processes should be evaluated in advance in order to assess adequate groundwater resources assessmen

    Identificación de flujos entre acuíferos a nivel regional en base a datos hidroquímicos (Alt Empordà, NE España)

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    A escala regional, los flujos de agua subterránea entre formaciones hidrogeológicas condicionan su ba lance hídrico y, con él, su régimen de explotación. En este estudio se caracteriza la dinámica hidrogeológica a nivel regional de la depresión del Alt Empordà (Girona, NE España) en base a datos hidroquímicos, con el objetivo de identificar flujos de agua subterránea entre las formaciones que constituyen la zona de recarga (relieves circundantes) y la depresión. En este sistema, el ión sulfato resulta un trazador adecuado para identificar los procesos hidroquímicos y de mezcla que acontecen en este zona. Los datos presentados sugieren que la presencia de sulfato, y por consiguiente la recarga, se debe a aportaciones de flujos profundos, en algunos casos desde las unidades geológicas inferiores, ajenos a la recarga local por precipitación desde la superficie.At a regional scale, groundwater flow between aquifer systems controls their water budget and, therefore, its exploitation regime. This study characterizes the hydrogeology at a regional level of the Alt Empordà Basin (Girona, NE Spain). Our goal consists in recognizing recharge flowpaths, based on hydrochemical data, between the aquifer systems located in the ranges (recharge) areas and these within the basin. Sulfate stands as an appropriate tracer to identify hydrochemical as well as mixing processes and, therefore, recharge relationships. Field data suggest that sulfate occurrence is related to deep groundwater fluxes unrelated to the local rainfall recharge.Universidad Nacional de La Plat

    Nitrate pollution of groundwater; all right…, but nothing else?

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    Contamination from agricultural sources and, in particular, nitrate pollution, is one of the main concerns in groundwater management. However, this type of pollution entails the entrance of other substances into the aquifer, as well as it may promote other processes. In this study, we deal with hydrochemical and isotopic analysis of groundwater samples from four distinct zones in Catalonia (NE Spain), which include 5 different aquifer types, to investigate the influence of fertilization on the overall hydrochemical composition of groundwater. Results indicate that intense fertilizer application, causing high nitrate pollution in aquifers, also homogenize the contents of the major dissolved ions (i.e.; Cl(-), SO4(2-), Ca(2+), Na(+), K(+), and Mg(2+)). Thus, when groundwater in igneous and sedimentary aquifers is compared, significant differences are observed under natural conditions for Cl(-), Na(+) and Ca(2+) (with p-values ranging from <0.001 to 0.038), and when high nitrate concentrations occur, these differences are reduced (most p-values ranged between 0.054 and 0.978). Moreover, positive linear relationships between nitrate and some ions are found indicating the magnitude of the fertilization impact on groundwater hydrochemistry (with R(2) values of 0.490, 0.609 and 0.470, for SO4(2-), Ca(2+) and Cl(-), respectively). Nevertheless, the increasing concentration of specific ions is not only attributed to agricultural pollution, but to their enhancing effect upon the biogeochemical processes that control water-rock interactions. Such results raise awareness that these processes should be evaluated in advance in order to assess an adequate groundwater resources management.Peer ReviewedPostprint (author's final draft

    Identification of nitrate leaching loss indicators through regression methods based on a meta-analysis of lysimeter studies

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    This study presents a meta-analysis of 12 experiments that quantify nitrate-N leaching losses from grazed pasture systems in alluvial sedimentary soils in Canterbury (New Zealand). Mean measured nitrate-N leached (kg N/ha × 100 mm drainage) losses were 2.7 when no urine was applied, 8.4 at the urine rate of 300 kg N/ha, 9.8 at 500 kg N/ha, 24.5 at 700 kg N/ha and 51.4 at 1000 kg N/ha. Lismore soils presented significantly higher nitrate-N losses compared to Templeton soils. Moreover, a multiple linear regression (MLR) model was developed to determine the key factors that influence nitrate-N leaching and to predict nitrate-N leaching losses. The MLR analyses was calibrated and validated using 82 average values of nitrate-N leached and 48 explanatory variables representative of nitrogen inputs and outputs, transport, attenuation of nitrogen and farm management practices. The MLR model (R2 = 0.81) showed that nitrate-N leaching losses were greater at higher urine application rates and when there was more drainage from rainfall and irrigation. On the other hand, nitrate leaching decreased when nitrification inhibitors (e.g. dicyandiamide (DCD)) were applied. Predicted nitrate-N leaching losses at the paddock scale were calculated using the MLR equation, and they varied largely depending on the urine application rate and urine patch coverage

    Occurrence et devenir des polluants émergents (antibiotiques) dans un aquifère alluvial et leur influence sur les bactéries multi-résistantes (Bas-Fluvià, Catalogne)

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    Les polluants émergents (EOCs, et parmi eux des antibiotiques vétérinaires) par rapport à l'utilisation de fumier dans les activités agricoles sont de grande préoccupation sur la qualité des eaux. Ils sont ainsi responsables des changements dans les communautés microbiologiques existants dans les aquifères qui, à son tour, peuvent supposer un risque pour la santé humaine. Ce travail vise à étudier le comportement des antibiotiques dans les eaux et leur influence sur la capacité des communautés microbiennes à résister à leur présence. Le site d'étude est localisé dans l'aquifère alluvial du Fluvià à l'Empordà (NE Catalogne, Espagne). Les échantillons correspondent à des eaux souterraines (47), des eaux de surface (7) et des effluents de stations de traitement d'eaux usées (2). Tous les échantillons ont été analysés pour les paramètres hydrochimiques, isotopiques, des EOCs et des gènes de résistance aux antibiotiques. 11 antibiotiques distincts ont été trouvés (concentrations à l'ordre de ng/L) dans des échantillons d'eaux souterraines, correspondant à 4 groupes chimiques : fluoroquinilones (ciprofloxacine, danofloxacine, enrofloxacine, norfloxacine, ofloxacine, orbifloxacine), les macrolides (azithromycine), les quinolones (fluméquine, acide oxolinique, acide pipémidique) et les sulfamides (sulfaméthoxazole). Dans les échantillons d'eaux de surface, 5 antibiotiques différents ont été quantifiés à partir de 2 groupes chimiques : fluoroquinilones (ciprofloxacine, enrofloxacine, norfloxacine, orbifloxacine) et les sulfamides (sulfaméthoxazole). La résistance des communautés microbiennes a également été testé positive. Ce cas d'étude souligne les multiples aspects de la pollution aux antibiotiques qui peut influencer la qualité des eaux souterraines

    Occurrence et devenir des polluants émergents (antibiotiques) dans un aquifère alluvial et leur influence sur les bactéries multi-résistantes (Bas-Fluvià, Catalogne)

    No full text
    Les polluants émergents (EOCs, et parmi eux des antibiotiques vétérinaires) par rapport à l'utilisation de fumier dans les activités agricoles sont de grande préoccupation sur la qualité des eaux. Ils sont ainsi responsables des changements dans les communautés microbiologiques existants dans les aquifères qui, à son tour, peuvent supposer un risque pour la santé humaine. Ce travail vise à étudier le comportement des antibiotiques dans les eaux et leur influence sur la capacité des communautés microbiennes à résister à leur présence. Le site d'étude est localisé dans l'aquifère alluvial du Fluvià à l'Empordà (NE Catalogne, Espagne). Les échantillons correspondent à des eaux souterraines (47), des eaux de surface (7) et des effluents de stations de traitement d'eaux usées (2). Tous les échantillons ont été analysés pour les paramètres hydrochimiques, isotopiques, des EOCs et des gènes de résistance aux antibiotiques. 11 antibiotiques distincts ont été trouvés (concentrations à l'ordre de ng/L) dans des échantillons d'eaux souterraines, correspondant à 4 groupes chimiques : fluoroquinilones (ciprofloxacine, danofloxacine, enrofloxacine, norfloxacine, ofloxacine, orbifloxacine), les macrolides (azithromycine), les quinolones (fluméquine, acide oxolinique, acide pipémidique) et les sulfamides (sulfaméthoxazole). Dans les échantillons d'eaux de surface, 5 antibiotiques différents ont été quantifiés à partir de 2 groupes chimiques : fluoroquinilones (ciprofloxacine, enrofloxacine, norfloxacine, orbifloxacine) et les sulfamides (sulfaméthoxazole). La résistance des communautés microbiennes a également été testé positive. Ce cas d'étude souligne les multiples aspects de la pollution aux antibiotiques qui peut influencer la qualité des eaux souterraines

    Sorption properties and behaviour at laboratory scale of selected pharmaceuticals using batch experiments.

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    Despite the increasing public concern about the frequent occurrence of pharmaceuticals in the water bodies, their transport and fate are not yet well known; in particular in groundwater. In this laboratory study, batch experiments were conducted to investigate the sorption behaviour of selected pharmaceuticals. The choice of compounds was motivated by their chemical properties as well as by their occurrence at the relevant field sites. It included: antipyrine, atenolol, caffeine, carbamazepine, ciprofloxacin, diclofenac, ketoprofen, ofloxacin, and sulfamethoxazole. Sorption behaviour has already been investigated for some of these compounds (e.g. carbamazepine), but for the others (e.g. antipyrine, ketoprofen), extensive studies are missing so far. For the experiments, artificial and actual aquifer materials from complementary field sites were selected: technical coarse quartz sand and sediments from alluvial Vistrenque Aquifer, France (sandy loam), and fluvio-deltaic Baix Fluvia Aquifer, Spain (sandy clay loam, clay, and medium sand). In these field sites occurrence of pharmaceuticals in groundwater was previously stated, and the presented laboratory experiments were complementary to the field investigations. Five concentration steps for determining the sorption isotherms were investigated. Correlation analysis showed dependencies of K-coefficients of individual compounds and sediment properties; however, no clear, universal patterns for all compounds were found. Batch experiments suggest that sorption behaviour was governed by compound-specific properties rather than by sediment properties. These results contribute to the understanding sorption behaviour of pharmaceuticals in heterogeneous sediments, although some inconsistencies were revealed between laboratory scale results and field scale observations

    Boosting Rural Areas Revitalization in the Mediterranean through Cross-cutting Approach Based on Ecological and Social Resilience

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    Urban areas have been identified as one of the key challenges to tackle in the next decades. Most of the environmental impacts associated to urban contexts are linked to an unsustainable use of resources basically due to urban planning and society’s consumption behaviour. Currently, the paradigm of sustainable cities brought out in the past years situates urban contexts as an opportunity to reduce these impacts. There is a wide range of strategies focused on cities and their transition to a more sustainable urban model: compactness, sustainable mobility, energy efficiency, waste management and greening are some of the most relevant approaches with clear indicators and implementation plans. However, rural areas are still pending for  a precise strategy that highlights their ecological added value avoiding to be defined only as “not urban”. Rural areas should be emphasized from their productivity perspective and their key role in terms of resilience and adaptation to Climate Change. In the framework of the Interreg Med Programme, Thematic Communities are working on the capitalisation of projects from different kind of approaches of application in the Mediterranean Area. Four of these communities - Renewable Energy, Green Growth, Sustainable Tourism and Efficient Buildings - have several projects that present rural areas as one common territory of intervention. The aim of this paper is to expose the standards and goals proposed by the Interreg Med Thematic Communities for Rural Areas Revitalization as a resilience strategy in the Mediterranean Region, using a cross-cutting approach. The cross-cutting approach stresses the relation among the environment, society and economy: rural liveability, increasing RES production with sharing microgrid systems &amp; efficient buildings, as well as green economy based on sectors such as agricultural &amp; tourism activities. These standards and results will provide reference values to shape final policies recommendations. Consequently, the present paper is based on the joint cross-thematic effort and work from four thematic communities of the Interreg MED programme, previously mentioned. It includes some references to existing research studies, but the aim is to open the path to identify new challenges of Mediterranean rural areas and find potential solutions from a holistic approach

    Boosting Rural Areas Revitalization in the Mediterranean through Cross-cutting Approach Based on Ecological and Social Resilience

    No full text
    Urban areas have been identified as one of the key challenges to tackle in the next decades. Most of the environmental impacts associated to urban contexts are linked to an unsustainable use of resources basically due to urban planning and society’s consumption behaviour. Currently, the paradigm of sustainable cities brought out in the past years situates urban contexts as an opportunity to reduce these impacts. There is a wide range of strategies focused on cities and their transition to a more sustainable urban model: compactness, sustainable mobility, energy efficiency, waste management and greening are some of the most relevant approaches with clear indicators and implementation plans. However, rural areas are still pending for  a precise strategy that highlights their ecological added value avoiding to be defined only as “not urban”. Rural areas should be emphasized from their productivity perspective and their key role in terms of resilience and adaptation to Climate Change. In the framework of the Interreg Med Programme, Thematic Communities are working on the capitalisation of projects from different kind of approaches of application in the Mediterranean Area. Four of these communities - Renewable Energy, Green Growth, Sustainable Tourism and Efficient Buildings - have several projects that present rural areas as one common territory of intervention. The aim of this paper is to expose the standards and goals proposed by the Interreg Med Thematic Communities for Rural Areas Revitalization as a resilience strategy in the Mediterranean Region, using a cross-cutting approach. The cross-cutting approach stresses the relation among the environment, society and economy: rural liveability, increasing RES production with sharing microgrid systems & efficient buildings, as well as green economy based on sectors such as agricultural & tourism activities. These standards and results will provide reference values to shape final policies recommendations. Consequently, the present paper is based on the joint cross-thematic effort and work from four thematic communities of the Interreg MED programme, previously mentioned. It includes some references to existing research studies, but the aim is to open the path to identify new challenges of Mediterranean rural areas and find potential solutions from a holistic approach

    Electron beam remelting of operating surface of exhaust valves of aircraft engines

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    Translated from Russian (Avtomaticheskaya svarka 2000 (2) p. 39-40)Available from British Library Document Supply Centre-DSC:9023.190(10448)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
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