Methane and hydrogen in hyperalkaline groundwaters of the serpentinized Dinaride ophiolite belt, Bosnia and Herzegovina

Methane (CH4) in continental serpentinized peridotites (MSP) has been documented in numerous hyperalkaline (pH > 9) springs and gas seeps worldwide. With a dominantly abiotic origin, MSP is often associated with considerable amounts of hydrogen (H2), produced by serpentinization. Both gases may fuel microbial activity in igneous rocks and may have played roles in the origin of life. MSP is also a natural CH4 source for the atmosphere, not included in the global greenhouse-gas budget, yet. Here we document a new and major case of MSP, in the Dinaride ophiolite belt in Bosnia and Herzegovina. CH4 is dissolved (83-2706 mM) in low temperature (13-30 °C), hyperalkaline (pH 10 to 12.8) waters in six sites, sampled through springs and boreholes. Four sites (Slanac, Vlajici, Kulasi and Ljesljani) show CH4 isotopic signatures typical of abiotic MSP (d13C: -18.5 to -35.7‰; d2H: -221 to -335.4‰); two sites (Vaiceva and Kiseljak) show a dominantly biotic signature (d13C: -58.8 and -65.1‰; d2H: -310.8 and -226.8‰), probably due to mixing with gas from coal-beds adjacent to the ultramafic rocks. H2 concentration is highly variable (up to 348 mM), ethane, propane and butane reach 0.13 vol.% in total, and helium isotopic composition (R/Ra: 0.12 to 0.48) reflects a dominant crustal signature. The Ljesljani site features the highest pH (12.8) and CH4 emission (~9 ton y-1) in peridotite-hosted hyperalkaline groundwater documented so far. Geological and geochemical data converge towards the hypothesis that, as proposed in similar cases, CH4 was mainly generated by Sabatier reaction between H2 (from serpentinization) and CO2 (from C-bearing rocks, in tectonic contact with the ophiolite, or other CO2 sources). CH4-H2-H2O disequilibria and Sabatier reaction constraints suggest that CH4 is not formed in the hyperalkaline water, but in water-free or unsaturated rocks hosting opportune metal catalysts (e.g., chromitites). The amount of methane released to the atmosphere from individual springs is comparable to that of conventional biotic gas seeps/springs in sedimentary basins.Published286-2966A. Geochimica per l'ambienteJCR Journa

Geochemistry of european bottled water

In Europe, ca. 1900 "mineral water" brands are officially registered and bottled for drinking. Bottled water is groundwater and is rapidly developing into the main supply of drinking water for the general population of large parts of Europe. This book is the first state of the art overview of the chemistry of groundwaters from 40 European countries from Portugal to Russia, measured on 1785 bottled water samples from 1247 wells representing 884 locations plus additional 500 tap water samples acquired in 2008 by the network of EuroGeoSurveys experts all across Europe. In contrast to previously available data sets, all chemical data were measured in a single laboratory, under strict quality control with high internal and external reproducibility, affording a single high quality, internally consistent dataset. More than 70 parameters were determined on every sample using state of the art analytical techniques with ultra low detection limits (ICPMS, ICPOES, IC) at a single hydrochemical lab facility. Because of the wide geographical distribution of the water sources, the bottled mineral, drinking and tap waters characterized herein may be used for obtaining a first estimate of "groundwater geochemistry" at the scale of the European Continent, a dataset previously unavailable in this completeness, quality and coverage. This new data set allows, for the first time, to present a comprehensive internally consistent, overview of the natural distribution and variation of the determined chemical elements and additional state parameters of groundwater at the European scale. Most elements show a very wide range \u2013 usually 3 to 4 but up to 7 orders of magnitude \u2013 of natural variation of their concentration. Data are interpreted in terms of their origin, considering hydrochemical parameters, such as the influence of soil, vegetation cover and mixing with deep waters, as well as other factors (bottling effects, leaching from bottles). Chapters are devoted to comparing the bottled water data with those of European tap water and previously published datasets and discussing the implications of water chemistry for health. The authors also provide an overview of the legal framework, that any bottled water sold in the European Union must comply with. It includes a comprehensive compilation of current drinking water action levels in European countries, limiting values of the European Drinking/Mineral/Natural Mineral Water directives (1998/83/EC, 2003/40/EC, 2009/54/EC) and legislation in effect in 26 individual European Countries, and for comparison those of the FAO and in effect in the US (EPA, maximum contaminant level)

Geochemistry of European Bottled Waters.

Vengono riportate le concentrazioni di elementi in traccia delle acque minerali dell'Europa acquistate nei punti di vendit

Mercury in European agricultural and grazing land soils

Agricultural (Ap, Ap-horizon, 0–20 cm) and grazing land soil samples (Gr, 0–10 cm) were collected from a large part of Europe (33 countries, 5.6 million km2) at an average density of 1 sample site/2500 km2. The resulting more than 2 x 2000 soil samples were air dried, sieved to <2 mm and analysed for their Hg concentrations following an aqua regia extraction. Median concentrations for Hg are 0.030 mg/kg (range: <0.003–1.56 mg/kg) for the Ap samples and 0.035 mg/kg (range: <0.003–3.12 mg/kg) for the Gr samples. Only 5 Ap and 10 Gr samples returned Hg concentrations above 1 mg/kg. In the geochemical maps the continental-scale distribution of the element is clearly dominated by geology. Climate exerts an important influence. Mercury accumulates in those areas of northern Europe where a wet and cold climate favours the build-up of soil organic material. Typical anthropogenic sources like coal-fired power plants, waste incinerators, chlor-alkali plants, metal smelters and urban agglomerations are hardly visible at continental scales but can have a major impact at the local-scale