http://hdl.handle.net/2122/168 Mon, 20 May 2013 21:59:28 GMT 2013-05-20T21:59:28Z http://hdl.handle.net/2122/8698 Title: Influence of volcanic activity on the quality of water collected in roof water catchment systems at Stromboli Island (Italy) Authors: Madonia, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Cangemi, M.; Dip. DiSTeM, Università di Palermo; Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia Abstract: With the aim of detailing the interaction between volcanic emissions and water harvesting by Roof Water Catchment Systems (RWCSs), the present work illustrates the results of a study carried out at Stromboli Island, a small but densely populated active volcanic area in the South of Italy. Concentrations of major and trace elements determined in RWCS waters and sediments revealed clear clues of a contamination with gases and suspended particles of volcanic origin, even if the values of those contaminants considered by the World Health Organization as dangerous for human health are always belowtheMaximumAdmitted Concentration (MAC). In particular, cistern water showed a composition similar to local coastal rainwater, with dissolved ions related not only to sea aerosol but also to volcanic gases and ash leaching,with a secondary enrichment in Ca ions due to the interactionwith the limewashed surfaces of both roofs and cisternwalls. The simulation of the potential increase in dissolved chemical species due to volcanic ash deposition on the water catchment surfaces indicates the possible exceedance of the MAC for several species. The symptoms of fluorosis affecting elderly people who were young at the time of the 1930–40 volcanic crisis is a clue of a possible volcanogenic fluorine contamination. On the other way, the simulation of the digestion process on solid volcanogenic particulate ingested with drinkingwater highlighted a potential dramatic increase (orders of magnitudes) of dangerous element concentrations in stomach fluids above theirMACs. Despite the evidence of potential health risks induced by volcanic activity, no anamnesic evidence of related pathologies has been found among Stromboli population. This apparent discrepancy is solved taking into account the positive feedback among the good practice in maintaining clean conditions in the harvested waters and the prevalent fallout of volcanogenic ashes away from the main inhabited areas, favoured by the morphological setting of the island and its wind regime. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8698 2012-12-31T23:00:00Z http://hdl.handle.net/2122/7949 Title: Nitrate, sulphate and chloride contents in public drinking-water supplies in Sicily, Italy Authors: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Parello, F.; Università di Palermo, Dipartimento CFTA; Bonfanti, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Brusca, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Longo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Maugeri, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia Abstract: Water samples collected from public drinking-water supplies in Sicily were analysed for electric conductivity and for their chloride, sulphate and nitrate contents. The samples were collected as uniformly as possible from throughout the Sicilian territory, with an average sampling density of about 1 sample for every 7600 inhabitants. Chloride contents that ranged from 5.53 to 1302 mg/l were correlated strongly with the electric conductivity, a parameter used as a proxy for water salinity. The highest values are attributable to seawater contamination along the coasts of the island. High chloride and sulphate values attributable to evaporitic rock dissolution were found in the central part of Sicily. The nitrate concentrations ranged from 0.05 to 296 mg/l, with 31 samples (4.7% of the total) exceeding the maximum admissible concentration of 50 mg/l. Anomalous samples always came from areas of intensive agricultural usage, indicating a clear anthropogenic origin. The same parameters were also measured in bottled water sold in Sicily, and they all were within the ranges for public drinking-water supplies. The calculated mean nitrate intake from consuming public water supplies (16.1 mg/l) did not differ significantly from that of bottled water (15.2 mg/l). Although the quality of public water supplies needs to be improved by eliminating those that do not comply with the current drinking-water limits, at present it does not justify the high consumption of bottled water (at least for nitrate contents). Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/7949 2011-12-31T23:00:00Z http://hdl.handle.net/2122/7814 Title: Natural arsenic contamination in waters from the Pesariis village, NE Italy Authors: Petrini, R.; Slejko, F.; Lutman, A.; Pison, S.; Franceschini, G.; Zini, L.; Italiano, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Galic, A. Abstract: High arsenic (As) concentrations, [900 lg/L, were measured in Ca–Mg–SO4 waters from springs and drainages in the village of Pesariis in the Carnic Alps (NE Italy). Oxidation of the outcropping arsenian marcasite ore deposits of the area is proposed as the mechanism for As release into oxygenated waters during runoff. Nevertheless, the limited extension of the ore deposit and the relatively low As content of the mineralization suggest that sulfide weathering might not be the only process responsible for the highest As concentration in groundwaters. An additional mechanism involves As adsorption onto ferric iron particulate during oxidation, the drawdown in reducing environment at depth during water infiltration, and the release of ferrous iron and sorbed arsenic to the water columns by reductive dissolution of hydrous ferric oxides (HFO). This yields the observed Fe–As correlation. Newly formed HFO precipitates when groundwaters discharge to aerated conditions, leading to the removal of As, which strongly partitions into the iron-rich sediments, adsorbed onto the surface of amorphous Fe2O3 xH2O. The calculated and measured As concentration in sediments exceeds 10% by weight. Furthermore, geochemical and isotopic data indicate that the As-rich reservoir partly mixes with shallower aquifers, commonly tapped for drinking supply, representing a natural hazard for inhabitants. Fri, 31 Dec 2010 23:00:00 GMT http://hdl.handle.net/2122/7814 2010-12-31T23:00:00Z http://hdl.handle.net/2122/7107 Title: Elevated trace metals and REE contents in the CO2-rich groundwaters of Florina (N. Greece) a natural analogue of carbon storage systems Authors: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Brusca, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia Editors: Belviso, C.; Fiore, S.; Giannossi, M.L. Abstract: The Florina basin, being the main commercial source of CO2 in Greece, represents a good natural analogue for the study of the impact of geologic carbon storage. It is part of a NNW-SSE trending graben filled with ~600 m Plio-Pleistocene fluvial and lacustrine deposits. The area is characterized by the upflow of great quantities of geogenic CO2 probably associated to presently extinct Quaternary volcanic activity. The gas originates mainly from crustal sources but has also a minor (~10%) mantle contribution. This strong upflow of nearly pure CO2 can be recognized in industrially exploitable gas reservoirs, high pCO2 shallow groundwaters and surface gas manifestations. But the increased CO2 content has a deleterious impact on groundwater quality. Due to the increased aggressiveness of the low-pH CO2-rich waters with respect to the aquifer rocks, EU drinking water limits are exceed for many parameters (e.g. Electric conductivity, pH, Na+, SO42-, F-, Al, B, Ba, Fe, Mn and Ni). Considering the additional impact of widespread agricultural activities, which is recognizable in sometimes elevated NO3- contents, only few of the sampled waters (4 out of 40) could be used for potable purposes. Aquifer waters are also characterized by high REE contents with ΣREE up to ~12 µg/l. Shale-normalized profiles show positive La and Y anomalies and Ce negative anomalies probably indicating a main derivation from iron oxyhydroxide dissolution. The positive Eu anomaly evidences also carbonate dissolution while the enrichment in HREE is probably due to the abundant presence of HCO3-, which increases HREE solubility through complexation. Future developments of carbon capture and storage programs in the nearby sedimentary basin of Ptolemais and Servia have to carefully take in account the possible deterioration of their groundwater resources due to CO2 leaks from the storage reservoirs. Mon, 19 Sep 2011 22:00:00 GMT http://hdl.handle.net/2122/7107 2011-09-19T22:00:00Z http://hdl.handle.net/2122/6977 Title: Long-term continuous monitoring of the dissolved CO2 performed by using a new device in groundwater of the Mt. Etna (southern Italy) Authors: De Gregorio, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Camarda, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Longo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Cappuzzo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Giudice, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Gurrieri, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia Abstract: We present a new device for continuous monitoring of the concentration of CO2 dissolved in water. The device consists of a tube made of a polymeric semi-permeable membrane connected to an infrared gas analyser (IRGA) and a pump. Several laboratory experiments were performed to set the best operating condition and test the accuracy of measurements. We used the device for performing 20 months of continuous monitoring of dissolved CO2 concentration (DCC) in groundwater within a drainage gallery at Mt. Etna. The monitored groundwater intercepts the Pernicana Fault, along which degassing is observed related to volcano-tectonic activity. The acquired data were compared with continuous and discrete data obtained using existing methods. The measurements of DCC resulted in some period of the year well correlated with air temperature. We also found that long-term trends, as well as short-term variations, are probably linked to the dynamics of volcanic activity and/or perturbations in the local or regional stress fields. Thu, 31 Mar 2011 22:00:00 GMT http://hdl.handle.net/2122/6977 2011-03-31T22:00:00Z http://hdl.handle.net/2122/6651 Title: FITOVERT: A dynamic numerical model of subsurface vertical flow constructed wetlands Authors: Giraldi, D.; Department of Civil Engineering, University of Pisa, Pisa, Italy; De' Michieli Vitturi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Iannelli, R.; Department of Civil Engineering, University of Pisa, Pisa, Italy Abstract: This paper introduces a mathematical model (FITOVERT) specifically developed to simulate the behaviour of vertical subsurface flow constructed wetlands (VSSF-CWs). One of the main goals of the development of FITOVERT was to keep the complexity of the model to an acceptable level, so as to provide a practical tool for design and operation optimization. The dynamic formulation of the model allows to simulate the typical non stationary feeding-emptying operation of VSSF-CWs. FITOVERT is able to describe the water flow through porous media in unsaturated conditions, combined with evapotranspiration; its biochemical module describes the degradation of both organic matter and nitrogen; the transport in the liquid phase is implemented for both dissolved and particulate components; the oxygen transport in the gaseous phase of the soil and its exchange with the liquid phase are also considered. As a main advantage, compared to the few currently available dedicated numerical models, FITOVERT is able to handle the porosity reduction due to bacteria growth and accumulation of particulate components, so that the clogging process is also simulated as an effect of the pore size reduction on the hydraulic conductivity of the simulated system. The performance of the model was firstly analyzed by comparison with hydrodynamic tests recorded in an experimental VSSF-CW pilot plant: tracer test were carried out in three different saturation conditions (fully saturated, partially saturated, and completely drained). FITOVERT proved to accurately simulate the hydraulic behaviour of VSSF-CWs in both saturated and unsaturated conditions. The needs for model improvements and further calibration are finally discussed. Fri, 30 Apr 2010 22:00:00 GMT http://hdl.handle.net/2122/6651 2010-04-30T22:00:00Z http://hdl.handle.net/2122/6556 Title: Salinity variations in the water resources fed by the Etnean volcanic aquifers (Sicily, Italy): natural vs. anthropogenic causes Authors: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Bonfanti, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Brusca, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Longo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia Abstract: In this paper, in an attempt to reveal possible changes connected to natural or anthropogenic causes, the main results of hydrogeochemical monitoring carried out at Mount Etna are evaluated. We report on the salinity contents of the groundwaters that flow in fractured volcanics, which make up the flanks of the volcano. These waters, analyzed for major ion chemistry, were sampled regularly from 1994 to 2004. Basing on nonparametric Sen’s slope estimator, time series of groundwater composition reveal that the salinity of most of the Etnean aquifers increased by 0.5% to 3.5% each year during this period. This change in the water chemistry is clearly referable to the overexploitation of the aquifers. This increasing trend needs to be inverted urgently; otherwise, it will cause a shortage of water in the near future, because the maximum admissible concentration of salinity for drinking water will be exceeded. Fri, 31 Dec 2010 23:00:00 GMT http://hdl.handle.net/2122/6556 2010-12-31T23:00:00Z http://hdl.handle.net/2122/5749 Title: A structural and geophysical approach to the study of fractured aquifers in the Scansano-Magliano in Toscana Ridge, southern Tuscany, Italy Authors: Francese, R.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy; Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Bistacchi, A.; Dipartimento di Geologia e Geotecnologia, Università di Milano Bicocca, Milano, Italy; Morelli, G.; Geostudi Astier S.r.l., Livorno, Italy; Pasquarè, G.; Dipartimento di Geologia, Università di Milano, Milano, Italy; Praticelli, N.; Dipartimento di Geoscienze, Università di Padova, Padova, Italy; Robain, H.; Institute de Recherche pour le Développement, Bondy Cedex, France; Wardell, N.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy; Zaja, A.; Dipartimento di Geoscienze, Università di Padova, Padova, Italy Abstract: Fresh water availability has recently become a serious concern in the Italian Apennines, as various activities rely on a predictable supply. Along the ridge between Scansano and Magliano in Toscana, in southern Tuscany, the situation is further complicated by contamination of the nearby alluvial aquifers. Aquifers locally consist of thin fractured reservoirs, generally within low-permeability formations, and it can be difficult to plan the exploitation of resources based on conventional techniques. An integrated study based on geological data investigated the link between tectonics and groundwater circulation, to better define the hydrological model. After the regional identification of fault and fracture patterns, a major structure was investigated in detail to accurately map its spatial position and to understand the geometry and properties of the associated aquifer and assess its exploitation potential. The subsurface around the fault zone was clearly imaged using ground probing radar, two-dimensional and three-dimensional resistivity tomography, and three-dimensional shallow seismic surveys. The vertical and horizontal contacts between the different geological units of the Ligurian and Tuscan series were resolved with a high degree of spatial accuracy. Three-dimensional high-resolution geophysical imaging proved to be a very effective means of characterising small-scale fractured reservoirs. Tue, 30 Jun 2009 22:00:00 GMT http://hdl.handle.net/2122/5749 2009-06-30T22:00:00Z http://hdl.handle.net/2122/5720 Title: FITOVERT: A dynamic numerical model of subsurface vertical flow constructed wetlands Authors: Giraldi, D.; Department of Civil Engineering, University of Pisa, Pisa, Italy; De' Michieli Vitturi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Iannelli, R.; Department of Civil Engineering, University of Pisa, Pisa, Italy Abstract: This paper introduces a mathematical model (FITOVERT) specifically developed to simulate the behaviour of vertical subsurface flow constructed wetlands (VSSF-CWs). One of the main goals of the development of FITOVERT was to keep the complexity of the model to an acceptable level, so as to provide a practical tool for design and operation optimization. The dynamic formulation of the model allows to simulate the typical non stationary feeding-emptying operation of VSSF-CWs. FITOVERT is able to describe the water flow through porous media in unsaturated conditions, combined with evapotranspiration; its biochemical module describes the degradation of both organic matter and nitrogen; the transport in the liquid phase is implemented for both dissolved and particulate components; the oxygen transport in the gaseous phase of the soil and its exchange with the liquid phase are also considered. As a main advantage, compared to the few currently available dedicated numerical models, FITOVERT is able to handle the porosity reduction due to bacteria growth and accumulation of particulate components, so that the clogging process is also simulated as an effect of the pore size reduction on the hydraulic conductivity of the simulated system. The performance of the model was firstly analyzed by comparison with hydrodynamic tests recorded in an experimental VSSF-CW pilot plant: tracer test were carried out in three different saturation conditions (fully saturated, partially saturated, and completely drained). FITOVERT proved to accurately simulate the hydraulic behaviour of VSSF-CWs in both saturated and unsaturated conditions. The needs for model improvements and further calibration are finally discussed. Wed, 31 Dec 2008 23:00:00 GMT http://hdl.handle.net/2122/5720 2008-12-31T23:00:00Z http://hdl.handle.net/2122/5714 Title: Hydrodynamics of vertical subsurface flow constructed wetlands: Tracer tests with rhodamine WT and numerical modelling Authors: Giraldi, D.; Department of Civil Engineering – University of Pisa, Pisa, Italy; De' Michieli Vitturi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Zaramella, M.; Department of Hydraulic, Maritime, Environmental and Geotechnical Engineering – University of Padua, Padova, Italy; Marion, A.; Department of Hydraulic, Maritime, Environmental and Geotechnical Engineering – University of Padua, Padova, Italy; Iannelli, R.; Department of Civil Engineering – University of Pisa, Pisa, Italy Abstract: Typical unsteady unsaturated conditions can profoundly affect the hydrodynamics of vertical subsurface flow constructed wetlands. In this study we analyzed the hydrodynamics of a 33 m2 vertical flow pilot plant, treating municipal secondary effluents. Three different saturation conditions were analyzed under several constant flux regimes: complete saturation, partial saturation with the free water table 20 cm over the bottom of the bed, and complete drainage. Tracer tests were performed in steady state conditions by dosing rhodamine WT as square input signals. Breakthrough curves were analyzed by means of both a classical residence time distribution analysis and an originally developed numerical plug-flow model with longitudinal dispersion adapted to the unsaturated conditions. We found that the degree of global mixing in the vertical flow constructed wetland increased as the water content increased; this effect was controlled by the hydraulic residence time of the system. Conversely, the degree of local mixing was inversely affected by water content; the dispersivity was 4.5, 10, and 14 cm for fully saturated, partially saturated and draining conditions, respectively. We explain the dependency of dispersivity on water content in physical terms; however, further studies are needed to mathematically include this relationship in numerical models that describe the behaviour of vertical flow constructed wetlands. Sun, 08 Feb 2009 23:00:00 GMT http://hdl.handle.net/2122/5714 2009-02-08T23:00:00Z