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Firenze, Italy

Raco B.,CNR Institute of Neuroscience | Battaglini R.,Massa Spin off Srl | Lelli M.,CNR Institute of Neuroscience
Environmental Science and Pollution Research | Year: 2010

Background, aim and scope: Landfill gas (LFG) tends to escape from the landfill surface even when LFG collecting systems are installed. Since LFG leaks are generally a noticeable percentage of the total production of LFG, the optimisation of the collection system is a fundamental step for both energy recovery and environmental impact mitigation. In this work, we suggest to take into account the results of direct measurements of gas fluxes at the air-cover interface to achieve this goal. Materials and methods: During the last 5 years (2004-2009), 11 soil gas emission surveys have been carried out at the Municipal Solid Waste landfill of Legoli (Peccioli municipality, Pisa Province, Italy) by means of the accumulation chamber method. Direct and simultaneous measurements of CH4 and CO2 fluxes from the landfill cover (about 140,000 m2) have been performed to estimate the total output of both gases discharged into the atmosphere. Three different data processing have been applied and compared: Arithmetic mean of raw data (AMRD), sequential Gaussian conditional simulations (SGCS) and turning bands conditional simulations (TBCS). The total amount of LFG (captured and not captured) obtained from processing of direct measurements has been compared with the corresponding outcomes of three different numerical models (LandGEM, IPCC waste model and GasSim). Results: Measured fluxes vary from undetectable values (<0.05 mol m-2 day-1 for CH4 and <0.02 mol m-2 day-1 for CO2) to 246 mol m-2 day-1 for CH4 and 275 mol m-2 day-1 for CO2. The specific CH4 and CO2 fluxes (flux per surface unit) vary from 1.8 to 7.9 mol m-2 day-1 and from 2.4 to 7.8 mol m-2 day-1, respectively. Discussion: The three different estimation methodologies (AMRD, SGCS and TBCS) used to evaluate the total output of diffused CO2 and CH4 fluxes from soil provide similar estimations, whereas there are some mismatches between these results and those of numerical LFG production models. Isoflux maps show a non-uniform spatial distribution, with high-flux zones not always corresponding with high-temperature areas shown by thermographic images. Conclusions: The average value estimated over the 5-year period for the Legoli landfill is 245 mol min-1 for CH4 and 379 mol min-1 for CO2, whereas the volume percentage of CH4 in the total gas discharged into the atmosphere varies from 29% to 51%, with a mean value of 39%. The estimated yearly emissions from the landfill cover is about 1.29 × 108 mol annum-1 (2,100 t year-1) of CH4 and 1.99 × 108 mol annum-1 (8,800 t year-1) of CO2. Considering that the CH4 global warming potential is 63 times greater than that of CO2 (20 a time horizon, Lashof and Ahuja 1990), the emission of methane corresponds to 130,000 t annum-1 of CO2. Recommendations and perspectives: The importance of these studies is to provide data for the worldwide inventory of CH4 and CO2 emissions from landfills, with the ultimate aim of determining the contribution of waste disposal to global warming. This kind of studies could be extended to other gas species, like the volatile organic compounds. © 2010 Springer-Verlag.

Raco B.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,Institute of Materials Science | Cerrina Feroni A.,CNR Institute of Geosciences and Earth Resources | And 2 more authors.
Journal of Geochemical Exploration | Year: 2013

This study investigates the chemistry (major and minor elements) and the stable isotopic composition of water (δ18O and δ2H) and carbon in dissolved inorganic carbon (δ13CDIC) in domestic bottled waters collected on the Italian market.The hydrogen and oxygen isotope ratios of 52 samples of bottled water range from -13.8% to -5.5%, for δ18O and from -99% to -36%, for δ2H. This observed isotopic variability of water (δ18O and δ2H) falls within and spans most of the normal range for Italian meteoric waters suggesting that bottled water isotope ratios preserve information about the water sources from which they were derived. This investigation helped also to determine the natural origin of bottled water, and to indicate differences between the natural and production processes. The production process may influence the isotopic composition of waters. No such modification was observed for sampled waters.For identifying the origin of CO2 in waters, natural source or added exogenous CO2 of industrial origin, the 13C/12C ratio in the dissolved inorganic carbon (DIC) of carbonated bottled water is analyzed. The δ13C and δ18O, in DIC, range from -21% to 0.8% and from -25.5% to -7.7% respectively. The isotopic compositions of DIC (1.5 to -7%) of natural sparkling Italian waters indicate that an endogenous CO2 from the deep zones of earth's crust is the origin of the gas in these waters. In still waters grouping the δ13CDIC values indicates mixing of shallow and deeper mineral water in the aquifer and interrelations between soil CO2 and the water-rock interaction. Moreover δ13CDIC values in bottled waters are in accordance with the δ13C values of the aquifers from which they are pumped out.The isotope ratio data assure that the isotopic fingerprint can be used for the authentication of bottled waters and for the certification of the source of bottled water products, and also, as a tool of characterizing an increasingly important component of the human diet. In addition, the carbon isotopic methods applied, can be used for distinguishing the origin of carbon dioxide in the bottled water for regulatory and consumer control applications.Finally, authentication and identification of CO2 origin, is an important and growing challenge to organism in certifying the quality of bottled waters and is a critical in ensuring that bottled water production does not damage the water resources. © 2012 Elsevier B.V.

Raco B.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,CNR Institute of Geosciences and Earth Resources | Dotsika E.,Greek National Center For Scientific Research | Poutoukis D.,General Secretariat for Research and Technology | And 2 more authors.
Food Chemistry | Year: 2015

Stable isotopes have been applied to determine the origin assignment and verify the geographical provenance that is considered important characteristics of wine products both for consumers and the international regulations, of wines. Stable isotope analyses of 18O/16O, D/H and 13C/12C ratio for the detection of origin and of adulteration in wine are discussed in this study. The δ13C analysis of ethanol and wines water δ18O underlines the importance of the photosynthetic pathway and the environmental conditions of wine. Also we discuss the main factors that are responsible for the differentiation of the oxygen isotope ratios of wine water. Data interpretation demonstrated the efficacy of δ18O analysis not only in the wine but also in grape berries, preferably if the determination of the δ18O value is employed together with the determination of the δ2H isotope content of wine, for the detection of the geographical origin of wine. © 2014 Elsevier Ltd. All rights reserved.

Raco B.,CNR Institute of Neuroscience | Dotsika E.,CNR Institute of Neuroscience | Dotsika E.,Institute of Materials Science | Battaglini R.,Massa Spin off Srl | And 3 more authors.
Water, Air, and Soil Pollution | Year: 2013

Geochemical characterization of two landfills, one closed and the other still active, both located near Komotini (Thrace, Greece), has been carried out. The aim was to provide an integrated and reliable methodology for a rapid assessment of the real impact of a municipal solid waste landfill, in the main environmental matrices (air and water) of the surrounding areas. The chemical (CO2, CH4, CO, H2, N2, and O 2 + Ar) and isotopic characterization (δ13C (CO2) and δ13C(CH4)) of landfill gas and chemical (Na+, K+, Ca2+, Mg2+, Cl-, SO4 2-, HCO3 -, NH4 +, NO3 -, NO2 -, B, COD, Fe, Mn, As, Cr, Ni, Cu, Zn, Cd, Pb, and Hg) and isotopic analysis (δD, δ18O, tritium content, and δ13CDIC) of leachate, stream waters and groundwaters, and flux survey on the air-soil interface has been carried out. Combined chemical and isotopic analysis of the fluids collected inside and in the surroundings of the Komotini landfills supply a detailed picture of biogas emission and composition as well as of leachate chemistry and interaction with local waters. The results arising in this case study demonstrate that it is possible to propose a quick and reliable geochemical protocol to get a detailed picture of the state of health of the environment around a landfill. © 2013 Springer Science+Business Media Dordrecht.

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