3,439 research outputs found
Gli isotopi ambientali ed il ciclo dell'acqua.
No full textL'applicazione delle tecniche isotopiche nel campo dell'idrogeologia risulta utile per la definizione dei movimenti dell'acqua nei serbatoi naturali e la messa in evidenza delle interazioni che avvengono con il mondo minerale e biologico
Hydrogeologic investigation of ophiolitic massifs in northern Apennines (Trebbia Valley)
No full text
Utilizzo delle tecniche isotopiche (15NNO3 e 18ONO3) per la determinazione dell'origine dei nitrati delle acque sotterranee della Lomellina
No full textSeychelles aquifer studied to assess water quality
No full textAssessment of groundwater quality in La Digue using hydrochemistry and environmental isotope
Isotopes demarcate precious water resources in Mauritius
No full textassessment of groundwater resources and aquifer pollution with the use of environmental isotopes in Mauritiu
Dynamic processes in Venice region outlined by environmental isotopes
No full textResearch carried out in the last 40 years has shown the scientific importance of groundwater circulation both in the Northern Adriatic sea bed and within the uppermost sedimentary layers of the Venice lagoon and of the Venice plain. Hydrodynamic processes are strictly controlled by a well-cemented sedimentary horizon lying under and around Venice (‘caranto’), which plays the role of regional aquitard. This layer was attributed to the subaerial cementation of the Flandrian (8–10 ka Before Present) sedimentary surface. The caranto is generalised as a
continuum horizon, being an easy explanation for several environmental, hydrogeological and geotechnical problems, e.g., a base layer for landfills, a confining layer for deep aquifers and the best substratum for locating the oak wooden pile-dwelling needed to support the largest buildings. The preservation of the isotope signal within the deep aquifers and aquiclude system records the changes in surface and groundwater characteristics and suggests the present and past recharge regimes. In this region, the heavily perturbed hydrodynamic conditions do not allow for the use of isotopic signals to derive a correct reconstruction of the present recharge. The perturbations induced by the intensive anthropogenic activity force to follow climate evolution when researching deep groundwater and pore waters. In addition, the presence of carbonatic rocks inside terrigeneous sediments affects the reconstruction of the past. Results indicate that carbonatic rocks are created by seepage, through the sediments, of gaseous carbon compounds from decaying organic layers. The gas interactions with the intra-sedimentary saline and fresh waters produce CO2, inducing the sediments’ cementation
In Memory of Professor Giovanni Maria Zuppi
No full textAbstractAt the 14th Water-Rock Interaction Symposium, a special session was devoted to the memory of Professor Gian Maria Zuppi, who passed away in May 2011. The text below describes the main stages of his career, his scientific activities, and some of his personality traits
Tackling the salinity-pollution nexus in coastal aquifers from arid regions using nitrate and boron isotopes
No full textSalinization and nitrate pollution are generally ascertained as the main issues affecting coastal aquifers worldwide. In arid zones, where agricultural activities also result in soil salinization, both phenomena tend to co-exist and synergically contribute to alter groundwater quality, with severe negative impacts on human populations and natural ecosystems’ wellbeing. It becomes therefore necessary to understand if and to what extent integrated hydrogeochemical tools can help in distinguishing among possible different salinization and nitrate contamination origins, in order to provide adequate science-based support to local development and environmental protection. The alluvial plain of Bou-Areg (North Morocco) extends over about 190 km2 and is separated from the Mediterranean Sea by the coastal Lagoon of Nador. Its surface is covered for more than 60% by agricultural activities, although the region has been recently concerned by urban population increase and tourism expansion. All these activities mainly rely on groundwater exploitation and at the same time are the main causes of both aquifer and lagoon water quality degradation. For this reason, it was chosen as a case study representative of the typical situation of coastal aquifers in arid zones worldwide, where a clear identification of salinization and pollution sources is fundamental for the implementation of locally oriented remedies and long-term management strategies. Results of a hydrogeochemical investigation performed between 2009 and 2011 show that the Bou-Areg aquifer presents high salinity (often exceeding 100 mg/L in TDS) due to both natural and anthropogenic processes. The area is also impacted by nitrate contamination, with concentrations generally exceeding the WHO statutory limits for drinking water (50 mg/L) and reaching up to about 300 mg/L, in both the rural and urban/peri-urban areas. The isotopic composition of dissolved nitrates (δ15NNO3 and δ18ONO) was used to constrain pollution drivers. The results indicate two main origins for human-induced pollution: (i) manure and septic effluents, especially in urban areas, and (ii) synthetic fertilizers in agricultural areas. In the latter, δ15N-enriched values highlight a mixture of those sources, possibly related to unbalanced fertilization and agricultural return flow. Boron isotopes (δ11B) were hence studied to further distinguish the nitrate origin in the presence of multiple sources and mixing processes. The results indicate that in the study area, the high geochemical background for B and Cl, associated to the complex water-rock interaction processes, limit the application of the coupled δ11B and δ15N isotopic systematics to the detection of sources of groundwater pollution. In fact, despite the exceedingly high nitrate contents, the depleted δ11B values that characterize synthetic fertilizers and sewage leakages could not be detected. Therefore, even if in saline groundwater the anthropogenic contribution has a negligible effect in terms of salinity input, with both sewage and irrigation water not very charged, the associated nitrate content fuels up water-rock interaction processes, eventually leading to a mineralization increase
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