Search

The study deals with the analyses of springs and wells at the base of Montepugliano Hill that represents the SE edge of the wide carbonate Matese massif (Campania, southern Italy). At the base of the hill, from west to east and for almost one kilometre, cold springs HCO3-Ca type (Grassano springs, ~ 4.5 m3/s; TDS: about 0.45 g/L) pass to hypothermal, HCO3-Ca type, sulphurous and CO2-rich springs (~ 1 m3/s with TDS > 1 g/L). Some of the latter are widely used inTelese SpaandCentro Relax Spa.Chemical and isotopic analyses carried out for this study support the hypothesis that all these waters (mineral and non-mineral) have the same catchment area, which is located in the Matese massif. As regards the sulphurous springs, they receive both meteoric waters infiltration and uprising of deeper waters rich in endogenous CO2and H2S gases through important faults systems. Far from these faults, the chemistry of groundwater is scarcely (or not at all) affected by these deep fluid enrichment processes. This scheme is very significant; in fact, when very important groundwater resources are present, it is possible to use both mineral waters in Spa and, in areas far from the faults, those not yet mineralized. Finally, at Montepugliano Hill, in the final stage of the flow path, groundwater is also affected by change in the microbiome: this could provide a basis for comparison between various mineral waters.

A hydrogeological and hydrogeochemical survey in the Cumae archaeological site (Phlegraean Fields, southern Italy) together with radon levels determination in groundwater have been carried out. The study was motivated by the fact that the site is often submerged by the outcrop of groundwater, threatening the integrity of ruins, and hence by the need to preserve such important archaeological park. The hydrostratigraphic and hydrogeological data revealed the presence of a multi-layered aquifer system, formed by a shallow unconfined and a deep semiconfined aquifer. The groundwater flow appeared to be strongly influenced by vertical and lateral lithological heterogeneity of volcanic-sedimentary deposits, as well as by groundwater pumping and drainage by surface micro-channel system. The dominant hydrochemical facies were Cl−-SO42 −-Na+-K+, HCO3−-Ca2 +-Mg2 + and HCO3− Na+-K+ types. These facies were affected by: i) dissolution and chemical weathering, ion exchange with volcanic-sedimentary deposits, ii) localized rise along faults and fractured zones of deep magmatic fluids highly mineralized, with outstanding levels of F−, 6.4 mg L− 1 in deep water and 3.3 mg L− 1 in shallow water, and 222Rn, 31,500 Bq m− 3 in deep water and 5400 Bq m− 3 in shallow water; iii) freshwater-saltwater interactions, induced by groundwater pumping.

The stable isotope composition of water (δ18O and δ2H) represents a useful tool to distinguish among different water pools along the soil-plant-atmosphere continuum. Using δ2H and δ18O as tracers helps gain a better understanding of plant root water uptake and dominant ecohydrological processes. To determine which pools of water are used for plant physiologic functions and returned to the atmosphere by transpiration, a common approach is to analyze the isotopic composition of water in both soil and plant. Cryogenic water extraction (CWE; Orlowski et al., 2016) is the most widely used laboratory-based technique to extract water from soil samples for isotopic analysis. However, recent studies have shown that the extraction conditions (time, temperature, and vacuum) and soil physical and chemical properties may affect the extracted soil-water isotope composition even significantly.We have developed an efficient and cost-effective cryogenic vacuum equipment to extract water from soil or vegetation and this presentation aims at discussing some preliminary results. The equipment has been specifically designed to meet the following requirements: i) enable to quantify the accuracy of a CWE continuous flow extraction line, and ii) identify a specific extraction standard protocol for soil and vegetation samples. Two experiments have been carried out to evaluate the isotope fractionation induced by the system and how different operational parameters (i.e. times and temperature of extraction) can affect the results. Firstly, a known water isotopic ratio was processed by the vacuum system to determine the measurement accuracy and reproducibility by comparing pre- and post-processed water isotopic signatures. The likely causes of observed biases induced by sample processing are assessed and a relevant correction procedure is suggested. Subsequently, measurements were carried out on replicated samples taken from two differently-textured soils that, after being dried, were saturated in the laboratory up to different water content values with water of known isotopic composition. Also, plant samples were collected from plants grown in a greenhouse and irrigated with water of known isotopic composition.Water from all samples was extracted by our CWE system and then analyzed using an isotope ratio mass spectrometer in Gas Bench mode for analyses and in temperature conversion elemental analysis (TC/EA) mode for. Preliminary results have quantified the isotope fractions on average of -1.6 ‰ for δ18O and 14.2 ‰ for δ2H. Normalization of stable isotopes from unknown samples according to observed fractionation has enabled the observed bias to become virtually zero, leading to a replicate reproducibility of δ18O and δ2H for soil water of 0.6 ‰ and 3 ‰, respectively. The analyses carried out up to now did not find statistical evidence that the soil types and soil-water contents may affect the extraction method and the accuracy of our protocol.

The stable isotope composition of water (δ18O and δ2H) represents a useful tool to distinguish among different water pools along the soil-plant-atmosphere continuum. Using δ2H and δ18O as tracers helps gain a better understanding of plant root water uptake and dominant ecohydrological processes. To determine which pools of water are used for plant physiologic functions and returned to the atmosphere by transpiration, a common approach is to analyze the isotopic composition of water in both soil and plant. Cryogenic water extraction (CWE; Orlowski et al., 2016) is the most widely used laboratory-based technique to extract water from soil samples for isotopic analysis. However, recent studies have shown that the extraction conditions (time, temperature, and vacuum) and soil physical and chemical properties may affect the extracted soil water isotope composition even significantly. We have developed an efficient and cost-effective cryogenic vacuum equipment to extract water from soil or vegetation and this presentation aims at discussing some preliminary results. The equipment has been specifically designed to meet the following requirements: i) enable to quantify the accuracy of a CWE continuous flow extraction line, and ii) identify a specific extraction standard protocol for soil and vegetation samples. Two experiments have been carried out to evaluate the isotope fractionation induced by the system and how different operational parameters (i.e. times and temperature of extraction) can affect the results. Firstly, a known water isotopic ratio was processed by the vacuum system to determine the measurement accuracy and reproducibility by comparing pre- and post-processed water isotopic signatures. The likely causes of observed biases induced by sample processing are assessed and a relevant correction procedure is suggested. Subsequently, measurements were carried out on replicated samples taken from two differently-textured soils that, after being dried, were saturated in the laboratory up to different water content values with water of known isotopic composition. Also, plant samples were collected from plants grown in a greenhouse and irrigated with water of known isotopic composition. Water from all samples was extracted by our CWE system and then analyzed using an isotope ratio mass spectrometer in Gas Bench mode for analyses and in temperature conversion elemental analysis (TC/EA) mode for. Preliminary results have quantified the isotope fractions on average of -1.6 ‰ for δ18O and 14.2 ‰ for δ2H. Normalization of stable isotopes from unknown samples according to observed fractionation has enabled the observed bias to become virtually zero, leading to a replicate reproducibility of δ18O and δ2H for soil water of 0.6 ‰ and 3 ‰, respectively. The analyses carried out up to now did not find statistical evidence that the soil types and soil water contents may affect the extraction method and the accuracy of our protocol. Powered by TCPDF (www.tcpdf.org).

Rationale Nitrate pollution represents one of the most important issues for ground and surface water quality and source identification is essential for developing effective mitigation practices. Nitrate isotopic fingerprinting can be utilized to identify the sources of nitrate pollution in aquifers. However, it is crucial to assess the performances (precision and accuracy) of the analytical procedure applied to measure the δ15 N and δ18 O values of nitrates from field samples to correctly apply this tool. Methods Nitrates were extracted from a large number of KNO3 samples using the AgNO3 method, and the δ15 N and δ18 O values of these nitrate extracts were measured by isotope ratio mass spectrometry. The availability of this dataset, comprising 693 unprocessed quality control (QC) KNO3 samples and 618 processed samples, allowed us to rigorously quantify the performance of the procedures employed. A salt doping experiment was also performed from which the effects of contaminants on the performance of the method could be ascertained. Results The overall instrumental reproducibility for the analysis of unprocessed QC samples was 0.5‰ and 2‰ for δ15 N and δ18 O values, respectively, and a strict dependence on signal amplitude was observed. No isotope fractionation was reported for reference samples that were processed according to the "identical treatment" principle (ITP) but normalized by unprocessed reference materials. A significant increase in the standard deviation (SD) was, however, observed compared with that for unprocessed samples. The SD of the processed QC samples allowed us to quantify the reproducibility of the entire procedure as 0.6‰ and 1.0‰ for δ15 N and δ18 O values, respectively. This was comparable with the system reproducibility when normalization using processed reference materials was applied according to the ITP. Conclusions Normalization with processed standards is essential to achieve high-precision measurements of the δ15 N and δ18 O values of nitrates extracted from unknown samples. This procedure allowed good accuracy to be guaranteed, and precision levels comparable with the observed instrumental performance to be achieved. A salt doping experiment showed a significant influence of the SO4 2- content on the δ15 N values.

Nitrate pollution represents one of the most important issues for ground and surface water quality and source identification is essential for developing effective mitigation practices. Nitrate isotopic fingerprinting can be utilized to identify the sources of nitrate pollution in aquifers. However, it is crucial to assess the performances (precision and accuracy) of the analytical procedure applied to measure the δNitrates were extracted from a large number of KNOThe overall instrumental reproducibility for the analysis of unprocessed QC samples was 0.5‰ and 2‰ for δNormalization with processed standards is essential to achieve high-precision measurements of the δ

In recent years, the critical zone (CZ) of catchments across the Mediterranean region has been influenced by rapid changes in both climate seasonality and land use/land cover. Rural ecosystems in southern Europe are experiencing prolonged droughts, seriously compromising water resources availability and crop yields whilst increasing the risk of wildfire occurrence. Rainy seasons are likely to be characterized by intense storms that trigger floods resulting in increasing damage severity. The negative effects of anthropogenic disturbance on hydrological ecosystem services can be tempered by demand-side adaptation options and appropriate investments to ensure water supply under drought conditions. To shed light on some of the scientific challenges related to these issues, a Critical Zone Observatory (CZO) has being established in the Alento River catchment. Although sampling campaigns and monitoring investigations have been carried out in this area for more than twenty-five years, a more systematic research program was recently started to take comprehensive measurements in representative sub-catchments of the study area. These sites are instrumented with advanced ground-based sensor network platforms that provide hydro-meteorological variables and fluxes in the groundwater-soil-vegetation-atmosphere system. Hydrological models of different complexity exploit the gathered dense information to assess the impact of land use and climate changes on key functions and services of the CZO in the Alento River catchment.

In semi-arid environments of the Near East water availability and soil fertility are limiting factors for crop growing and land use is locally adjusted to environmental features. In the last decades stable carbon and nitrogen isotope analyses on archaeobotanical cereal remains have been developed in order to reconstruct water and nutrient sources for grain filling. Diachronic studies on isotope records from single archaeological sites may help distinguish palaeoclimatic changes from human choices in agricultural practices, but they are actually missing. We have analysed 13C isotope discrimination (Δ13C) and N isotope composition (δ15N) on barley, emmer and wheat 14C-AMS dated grains from the archaeological site of Arslantepe, Malatya (South-Eastern Turkey). Our intent is to focus on the exceptionally long-term development of agricultural practices at the site from 4300 to 2000 BC. Stable isotope values of cereals show temporal trends in water supplies and manure application. Irrigation was provided to barley crops from 4300 to 3100 BC during the rise of centralised political organisation at the site. Different locations of barley fields are suggested from 3100 to 2000 BC when domestic economies are attested. In addition, the marked increase of barley δ15N values from 3350 to 3000 BC reveals manuring and/or cultivation in pasturelands due to the deposition of animal urea and dung. Wheat could have been grown close to the site, where irrigation water from natural springs was available. Emmer and wheat seem to have been cultivated in the same areas or directly in the same fields. During 3000–2500 BC intercropping cultivation is inferred by low δ15N values. The evidence of mixture crops confirms the increase of pasturelands during herders' occupations and the concentration of crop fields possibly around the site.

Phlegraean Fields, hydrogeological model, hydrochemical facies, Flowpath 2017, National meeting on hydrogeology 2017

This study describes the tests carried out to measure the isotopic composition of Boron (B) in water samples by use of the magnetic spectrometer and accelerator of the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) of Italy. B was extracted from water samples to obtain Boric acid (B(OH)3), which was then analyzed. We quantified the precision of our experimental system and the variability introduced by the chemical extraction measuring chemically untreated and treated pure B(OH)3samples. We found an instrumental precision around 10‰ (1σ), but, by increasing the number of replicates (>30), we obtained a standard deviation of the mean (σerr) around 3‰ or lower. We also tested whether the chemical extraction caused isotopic fractionation and found a small fractionation (ε = 5 ± 4‰) of treated samples normalized against untreated ones, compatible with zero at 2σ. In order to avoid δ11B biases, we decided to normalize unknown treated samples with treated standards. Finally, we measured δ11B of seawater and groundwater samples to test the analytical method, and obtained values of 30 ± 6‰ and −4 ± 4‰ respectively. We conclude that our experimental system is only suitable when remarkable (>10‰) δ11B differences exist among water samples, but cannot be used to measure natural differences (

River water infiltration into an unconfined porous aquifer (∼73% gravels, ∼12% sands, ∼15% silts and clays) in the Petrignano d’Assisi plain, central Italy, was traced combining isotopic techniques ( 222 Rn) with hydrochemical and hydrogeologic techniques in order to characterize the system under study. The 222 Rn gave information about the river water residence times within the aquifer and hydrochemical data, in a two-component mixing model, which allowed estimating the extent of mixing between surface waters and groundwater in wells at increasing distances from the river. The mixing measured in the well closer to the riverbank indicated a higher contribution of river water (up to 99%) during the groundwater recession phase and a moderate contribution (up to 64%) during the recharge phase. A model describing 222 Rn concentrations in groundwater as the result of both parent/daughter nuclide equilibrium and mixing process ( 222 Rn mixing/saturation model) was used to describe observed Rn concentrations and mixing index trends with the aim of evaluating water mean infiltration velocities along the transect. The stream bank infiltration velocities obtained by the model ranged from 1 m day −1 during groundwater recharge periods, when river water infiltration is lower, to 39 m day −1 during recession phases, when river water infiltration is larger.

Homepage > Generale > Archivio > Archivio completo Surface water – groundwater connectivity implications on nitrate cycling assessed by means of hydrogeologic and isotopic techniques in the Alento river basin (Salerno, Italy): preliminary data Luisa Stellato(a), Brunella Di Rienzo(a), Egidio Di Fusco(a), Mauro Rubino(a), Fabio Marzaioli(a) & Vincenzo Allocca(b) Antonio Salluzzo (c), Juri Rimauro(c), Nunzio Romano(d) & Fulvio Celico(e) (a) Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE), Dip. di Matematica e Fisica, Seconda Università degli Studi di Napoli, Viale Lincoln, 5, 81100 Caserta, Italy. E-mail: luisa.stellato@unina2.it (b) Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse (DiSTAR), Università di Napoli Federico II,Via Mezzocannone, 8, 80134, Napoli, Italy. (c) ENEA - Research Center of Portici, UTTP-CHIA, Environmental Chemistry Laboratory, Piazzale E. Fermi, 1, 80055 Portici (Napoli), Italy. (d) Dept. of Agriculture, Division of Agricultural, Forest and Biosystems Engineering, Università di Napoli Federico II, Via Università, 100, 80055, Portici (Napoli), Italy. (e) Interdisciplinary Centre for Studies on Water Resources, Department of Physics and Earth Sciences "Macedonio Melloni", University of Parma, Parco Area delle Scienze, 157/A, 43124, Parma, Italy. DOI: 10.3301/ROL.2016.98 Pages: 80-83 Abstract The knowledge of the mechanisms regulating the concentration of nutrients in rivers is of fundamental importance in maintaining the ecological functioning of streams. In particular, in the riverbed sediments, where the biogeochemical activity is enhanced, the study of retention mechanisms becomes crucial in order to determine the restoring capacity of a watercourse. In case of groundwater inflow, hot-spots in the recycling of nutrients within the riparian and hyporheic zones can be observed, influencing the nutrient load transported into the stream depending on retention mechanisms. Hence, the study of biotic and abiotic factors affecting retention and transport of nutrients in a riverine ecosystem at different spatial scales (from reach to catchment) becomes fundamental to understand the mechanisms regulating the concentration of nutrients, and in particular nitrates, in streams. The present work is developed within the framework of the IAEA Coordinated Research Project (CRP) "Environmental Isotopes and Age Dating Methods to Assess Nitrogen Pollution and Other Quality Issues in Rivers". The main scope is to find a reliable methodology to, spatially and temporally, quantify groundwater inflows to a river in order to study nitrates contamination of a groundwater dependent river ecosystem. In particular, the overall objectives of the proposed project are: i) the identification and quantification of spatio-temporal variation of the connectivity between groundwater and surface water; ii) the identification of the nitrate contamination sources of shallow groundwater; iii) the study of the nitrates retention and recycling mechanisms in riverbed sediments in critical effluent river reaches (key sites) in order to determine the importance of hyporheic and riparian zones. Here, the preliminary results of the hydrogeological, chemical and isotopic (222Rn, δ18O, δD) monitoring are presented and discussed.

222Rn was used to assess river–groundwater interactions within Castel di Sangro alluvial aquifer (Italy). The effectiveness of results obtained through this indicator was verified by also analyzing δ18O, major ions and temperature in both surface and groundwater, and carrying out piezometric head monitoring and discharge measurements. Hydrogeological investigations suggested that the river infiltrates into the aquifer in the south-eastern aquifer portion, while groundwater discharges into the river in the north-eastern portion. The latter phenomenon is supported by 222Rn data. Nevertheless, flow-through conditions cause the modelled discharge along this river reach, estimated by 222Rn data in a degassing-corrected two-component mixing model, to be greater than the measured discharge. Concerning river infiltration into the aquifer, δ18O, major ions and temperature data show that the river contribution is negligible in terms of aquifer recharge. Thus, the observed increase in 222Rn concentration in that portion of the aquifer is due to the enrichment process caused by infiltration of rainwater (222Rn free) which flows from the local divide area. Hence, in the study site, the use of only 222Rn to predict river–groundwater interactions causes some estimation inaccuracies and it must be coupled with other hydrochemical and hydrogeological parameters to gain a thorough understanding of such interactions.

The paper reports a methodology adopted to face problems related to quality assurance in soil sampling. The SOILSAMP project, funded by the Environmental Protection Agency of Italy (APAT), is aimed at (i) establishing protocols for soil sampling in different environments; (ii) assessing uncertainties associated with different soil sampling methods in order to select the "fit-for-purpose" method; (iii) qualifying, in term of trace elements spatial variability, a reference site for national and international inter-comparison exercises. Preliminary results and considerations are illustrated.

An experiment was performed at the Nuclear Power Plant of Garigliano (Caserta, Italy) to study the transfer of radionuclides from a contaminated soil to a lettuce crop and to check the validity of the generally accepted assumption of constant uptake. Measurements of specific activities of 137Cs, 60Co, and 40K were periodically performed by sampling plants during a growth period of 48 days. The specific activity was analysed as a function of plant mass and growth time to gain information on the dependence of radionuclide sorption on plant growth stage. The results (time-dependent uptake rate) were interpreted using a dynamic model which generalizes the transfer factor. In this model, the time dependence of the transfer factor is characterized by three parameters obtained from a non linear least-squares fit to the data. The resulting values were found to be dependent on the radionuclide. The relative growth rate of lettuce plants plays an important role in the transport process: maximum radionuclide transport occurs at 12 d for 60Co and 137Cs and 28 d for 40K. © 2002 Elsevier Science Ltd. All rights reserved.

The United Nations Environment Programme (UNEP) has performed a field survey at 11 sites located in Kosovo, where depleted uranium (DU) ammunitions were used by the North Atlantic Treaty Organization (NATO) during the last Balkans conflict (1999). Soil sampling was performed to assess the spread of DU ground contamination around and within the NATO target sites and the migration of DU along the soil profile. The 234U/238U and 235U/238U activity concentration ratios have been used as an indicator of natural against anthropogenic sources of uranium. The results show that levels of 238U activity concentrations in soils above 100 Bq x kg(-1) can be considered a 'tracer' of the presence of DU in soils. The results also indicate that detectable ground surface contamination by DU is limited to areas within a few metres from localised points of concentrated contamination caused by penetrator impacts. Vertical distribution of DU along the soil profile is measurable up to a depth of 10-20 cm. This latter aspect is of particular relevance for the potential risk of future contamination of groundwater.

A field study, organised, coordinated and conducted under the responsibility of the United Nations Environment Programme (UNEP), took place in Kosovo in November 2000 to evaluate the level of depleted uranium (DU) released into the environment by the use of DU ammunition during the 1999 conflict. Representatives of six different scientific organisations took part in the mission and a total of approximately 350 samples were collected. During this field mission, the Italian National Environmental Protection Agency (ANPA) collected water, soil, lichen and tree bark samples from different sites. The samples were analysed by alpha-spectroscopy and in some cases by inductively coupled plasma-source mass spectrometry (ICP-MS). The 234U/238U and 235U/238U activity concentration ratios were used to distinguish natural from anthropogenic uranium. This paper reports the results obtained on these samples. All water samples had very low concentrations of uranium (much below the average concentration of drinking water in Europe). The surface soil samples showed a very large variability in uranium activity concentration, namely from approximately 20 Bq kg(-1) (environmental natural uranium) to approximately 2.3 x 10(5) Bq kg(-1) (approximately 18000 mg kg(-1) of depleted uranium), with concentrations above environmental levels always due to DU. The uranium isotope measurements refer to soil samples collected at places where DU ammunition had been fired; this variability indicates that the impact of DU ammunitions is very site-specific, reflecting both the physical conditions at the time of the impact of the DU ammunition and any physical and chemical alteration which occurred since then. The results on tree barks and lichens indicated the presence of DU in all cases, showing their usefulness as sensitive qualitative bio-indicators for the presence of DU dusts or aerosols formed at the time the DU ammunition had hit a hard target. This result is particularly interesting considering that at some sites, which had been hit by DU ammunition, no DU ground contamination could be detected.

Metals and radionuclides in water systems can be easily adsorbed on suspended matter and, finally, they could eventually accumulate in the aquatic environment. The assessment of the health of a water body needs also sampling of the suspended matter fraction. In this paper sampling systems to characterise contaminants associated with the suspended matter fraction are described, with a particular attention to the collection and preservation of samples. Sampling must be representative, to obtain reliable conclusions. In this context it is stressed the importance of the evaluation of the sampling uncertainty, which contributes to a large extent to the total uncertainty.

An experiment has been performed at the nuclear power plant of Garigliano (Caserta, Italy), aiming at the measurement of transfer factors of 137 Cs and 60 Co radionuclides from the irrigation water to a soil–plant system, with particular attention to the influence on such transfers of the irrigation technique (ground or aerial). Tomato plants were irrigated weekly with water contaminated with 137 Cs and 60 Co (about 375 Bq/m 2 week), using both irrigation techniques. After 13 weeks, fruits, leaves, stems, roots and soil were sampled, and radionuclide concentrations were measured by high-resolution γ spectroscopy. It was found that the activity allocated to the plant organs is significantly dependent upon the irrigation technique, amounting to 2.1% and 1.6% of the activity given in the cultivation for aerial treatment and 0.4% and 0.3% for the ground treatment, for 137 Cs and 60 Co respectively. The activity absorbed by plants is allocated mainly in leaves (>55%), while less then 10% is stored in the fruits, for both irrigation techniques. Transfer factors (soil–plant and irrigation water–plant) of tomato plants and of weeds have been determined for 137 Cs and 60 Co, as well as for natural 40 K in the soil.

This paper concerns the evolution of the quality of the groundwater bodies over space and time, with special focus on nitrate. This case study deals with the qualitative status in alluvial-pyroclastic groundwater bodies located near Naples (southern Italy). The study is based on a significant hydrochemical database, gathered through: (i) groundwater sampling and water level monitoring, (ii) chemical analyses (Mg, Ca, K, Na, Cl, HCO3, SO4, NH4, F, Li, Br, metals) and (iii) isotopic analyses (δ15N and δ18O in NO3, δ18O and δD in water). Such data, processed using maps and graphical elaborations, has been very useful for identifying groundwater nitrate contamination. Finally, the application of isotope techniques has been important for understanding and following the trend of possible attenuation processes of nitrate content in groundwater.