166 research outputs found
Groundwater management in arid and semi-arid regions: challenges and opportunities
Groundwater quality degradation, Southern Europe, Middle East and North Africa (MENA) Region, groundwater resources management
shedding light on the invisible addressing the potential for groundwater contamination by plastic microfibers
The processes of microplastic fiber pollution in groundwater are unknown. The recent research on this contaminant threat is generally focused on surface waters (mainly oceans and rivers), while aquifer contamination is only marginally mentioned as an issue needing further investigation. Synthetic microfibers can be introduced into soils in different ways (e.g. wastewater treatment plants or greywater discharge, septic tank outflows, direct injection of contaminated water in cases of managed aquifer recharge, losing streams, etc.), and can thus reach aquifer systems due to leaching or infiltration in soil pores. Microfibers can then adsorb persistent bioaccumulative and toxic chemicals, which include persistent organic pollutants and metals, and become a carrier of harmful substances in the aquifer system, hence contributing to the overall contamination in both urban and rural areas. For this reason, it is of paramount importance, not only to assess the occurrence and fate of microplastic fibers in groundwater, but also to study the role of microplastics as carriers of contaminants within the aquifer and to advance standardization and organization of monitoring campaigns. Only by addressing these key challenges can hydrogeologists contribute to the state of the art on microplastic pollution and ensure that groundwater is not neglected in the environmental assessments tackling this contaminant of emerging concern
Vulnerability mapping as a tool to foster groundwater protection in areas subject to rapid population expansion: The case study of Abuja Federal Capital Territory (Nigeria)
Study region
Abuja Federal Capital Territory (FCT; Nigeria).
Study Focus
Rapid population growth has led to significant land use changes, with potential negative impacts on groundwater quality. However, the lack of understanding of hydrogeological settings, often due to limited data availability, is one of the main obstacles to sound planning in rapidly changing environments. To assess the specific groundwater vulnerability to nitrate, a DRASTIC-LU model was applied, combining the land use data from the last 20 years with the intrinsic aquifer vulnerability. This study represents the first attempt to assess aquifer vulnerability in the region.
New hydrogeological insights for the region
Results show that the Abuja FCT has been affected by a dramatic change in land use with an increase in urbanized and agricultural areas and may induce nitrate contamination in groundwater. Currently, several wells in the region are showing nitrate concentrations that exceed the statutory limit for drinking purposes. The comparison of DRASTIC-LU results with nitrate concentrations shows that the highest concentrations are found in urban/peri-urban areas. Although fertilizers are generally considered to be the main source of nitrate contamination, these results suggest a possible mixed (urban and agricultural) pollution origin. This investigation therefore represents a starting point for future nitrate monitoring assessments and for supporting decision makers with adequate information for urban planning in view of the expected population growth in the area
Coastal Aquifer Salinization in Semi-Arid Regions: The Case of Grombalia (Tunisia)
Groundwater resources are facing increasing pressure especially in semi-arid regions where they often represent the main freshwater resource to sustain human needs. Several aquifers in the Mediterranean basin suffer from salinization and quality degradation. This study provides an assessment of Grombalia coastal aquifer (Tunisia) based on multidisciplinary approach that combines chemical and isotopic (δ2H, δ18O, 3H, 14C and δ13C) methods to characterize the relation between groundwater quality variation and aquifer recharge. The results indicate that total dissolved solids exceed 1000 mg/L in the most of samples excepting the recharge area. In addition to water–rock interaction, evaporation and nitrate pollution contributing to groundwater mineralization, the reverse cation exchange process constitute an important mechanism controlling groundwater mineralization with enhancing risk of saltwater intrusion. Environmental isotope tracers reveal that groundwater is evolving within an open system to close system. A significant component of recent water that is recharging Grombalia aquifer system is confirmed by applying correction models based on the δ13C values and 14C activities and tritium contents. However, this recharge, which is mainly associated to the return flow of irrigation water, contributes to the groundwater salinization, especially for the shallow aquifer
Teste de imunofluorescência indireta para a detecção de anticorpos contra o vÃrus da encefalite St.Louis
An in house indirect immmunofluorescence assay ( IFA ) in relation to neutralization (NT) reference test, was assessed as a fast and cheap method to carry out serological surveys for St. Louis Encephalitis virus (SLE). Sera obtained from 213 blood donors were analyzed by both tests. The prevalence of seropositivity obtained with IFA was lower than (30.98%) that observed on NT (41.78%). The relative specificity rate of IFA was 96.77% whereas its relative sensitivity rate was 69.66%. Kappa index showed a good correlation between both tests. The results indicate that neutralization assay is still the serological test with the highest sensitivity and specificity relative rates for detecting antibodies against SLE virus. Nevertheless, the IFA could be useful as an alternative test in order to learn the circulation of the Flavivirus genus in a certain area.Com a finalidade de dispor de um método rápido e de baixo custo para realizar estudos séricos dirigidos ao virus da encefalite St.Louis (ESL), avaliamos a técnica de imunofluorescência indireta (IFI) artesanal em relação ao teste referência de neutralização (NT). Examinaram-se 213 soros de doadores de sangue. A prevalência dos anticorpos obtidas na técnica de IFI (30,98%) foi mais baixa do que a pesquisada com NT (41,78%). A taxa de especificidade relativa da IFI foi 96,77%, enquanto sua taxa de sensibilidade relativa foi 69,66%. O Ãndice Kappa demonstrou boa concordância entre os dois testes. Os resultados achados revelam que a NT continua sendo a técnica sorológica de maior taxa de especificidade e sensibilidade relativa para a detecção de anticorpos IgG para o vÃrus ESL. Contudo, a IFI poderia ser o teste de escolha em estudos da circulação desta arbovirose na população humana
Aguas del rÃo suquÃa: monitoreo y evaluación de riesgo de transmisión hÃdrica de virus entéricos con impacto en salud humana
El agua es una fuente importante de diseminación de agentes virales que se transmiten por vÃa fecal-oral y que genéricamente se denominan virus entéricos. Nuestro paÃs constituye una zona endémica para algunos de estos virus (hepatitis A, rotavirus, adenovirus, astrovirus, norovirus, enterovirus no polio) y por lo tanto la excreción fecal de estos virus puede considerarse permanente. Asimismo, los individuos infectados con virus entéricos emergentes, como es el virus de hepatitis E (HEV) y picobirnavirus, también los eliminan por materia fecal. De este modo, las aguas residuales constituyen una matriz hÃdrica con alta carga viral. En las últimas décadas se ha incrementado la fragilidad de los sistemas hÃdricos, reflejada en las dificultades para la evacuación de aguas residuales y la contaminación de espacios acuáticos destinados a recreación. En este marco, se verÃa favorecida la diseminación de virus entéricos en matrices acuosas superficiales, constituyendo estas aguas un riesgo de infección para la población expuesta. La legislación vigente establece, para el control de la contaminación microbiana de las aguas, el uso de indicadores estándares bacterianos. Sin embargo, recientes estudios han demostrado que estos indicadores no revelan satisfactoriamente la calidad viral de las aguas, por lo que el monitoreo especÃfico de los virus humanos en aguas superficiales cobra particular importancia. Objetivo general: llevar adelante un proyecto de desarrollo y transferencia de tecnologÃas, basado en una gestión integrada en red de investigación, para la recuperación, identificación, cuantificación y caracterización molecular de virus responsables de enfermedades de transmisión hÃdrica con impacto en la salud pública, en aguas del RÃo SuquÃa de la Provincia de Córdoba. Resultados esperados: se pretende como producto del desarrollo de este proyecto describir la calidad virológica de las aguas del RÃo SuquÃa y arribar a una propuesta para el monitoreo viral de aguas superficiales y la evaluación de riesgo de transmisión hÃdrica de virus entéricos a población expuesta. Importancia del proyecto: Aportar información a los programas sanitarios de la región sobre la situación de contaminación viral del RÃo SuquÃa, a fin de reforzar el sistema de saneamiento ambiental, mejorar el diagnóstico de calidad microbiológica de aguas superficiales e impulsar a programas de control para atenuar la diseminación de virus entéricos en nuestro medio. Los datos sobre el virus HEV serán los primeros disponibles para la región.Fil: Re, Viviana Elizabeth. Universidad Católica de Córdoba. Facultad de Ciencias QuÃmicas; ArgentinaFil: Nates, Silvia Viviana. Universidad Católica de Córdoba. Facultad de Ciencias QuÃmicas; Argentin
Groundwater and climate change: threats and opportunities
The important role of groundwater in adaptation to climate change is explored, and the competing threats and opportunities that climate change pose to groundwater systems are evaluated. This has been achieved through a review of current thinking on the complex interactions between human activities, climate and the hydrological cycle affecting groundwater quantity and quality, across different regions and time scales
A Firenze messe le basi per una Piattaforma internazionale per una corretta gestione delle risorse idriche sotterranee
II 10 dicembre, in occasione della Giornata dei Diritti umani si è tenuto a Firenze, nella monumentale Sala dei Cinquecento di Palazzo Vecchio, il 1° Workshop su: "Uso delle risorse idriche sotterranee in periodi siccitosi. Esperienze dalla Toscana al resto del mondo", organizzato dalla Sezione Italiana dell'Associazione Internazionale degli Idrogeologi (IAH) con Aquifera onlus e patrocinato, oltre che dalla Regione Toscana e dal Comune di Firenze (che ha gentilmente concesso l'uso della sala), dalla Società Geologica Italiana (SGI), dal Consiglio Nazionale dei Geologi (CNG) e dal'IAH-Burdon Groundwater Network for International Development [...]
Hydrochemical and Isotopic Features of the Khaung Daing Hot Spring (Inle lake, Southern Shan State, Myanmar)
Abstract The Inle lake watershed develops along a right-lateral strike-slip fault running parallel to the Sangaing fault, a major continental transform fault between the India and Sunda Plates. Located on the northwestern border of the Inle lake basin, the Khaung Daing hot spring outflows at a temperature of about 70C. This contribution represents a reconnaissance study of the spring and describes its main hydrochemical and isotopic features, compared to surface and ground waters in the watershed. The water pH is slightly acidic, and, compared to the other water samples from the watershed, shows an EC in the high range (57-1284μS/cm), the lowest pH and Eh values, and is Na-HCO 3 , whereas surface and ground waters are Ca(Mg)-HCO 3 type. The hot spring isotopic composition falls close to the Yangon Meteoric Water Line, indicating that, despite its temperature, it is not strongly modified by water-rock interaction processes. Preliminary results suggest that this hydrothermal water is likely related to deep meteoric and ground water circulation within a fault zone, in a region characterized by an elevated geothermal gradient
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