967 resultados para PURE WATER


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In this study, the very first geochemical and isotopic data related to surface and spring waters and dissolved gases in the area of Hontomín-Huermeces (Burgos, Spain) are presented and discussed. Hontomín-Huermeces was selected as a pilot site for the injection of pure (>99 %) CO2. Injection and monitoring wells are planned to be drilled close to 6 oil wells completed in the 1980’s. Stratigraphical logs indicate the presence of a confined saline aquifer at the depth of about 1,500 m into which less than 100,000 tons of liquid CO2 will be injected, possibly starting in 2013. The chemical and isotopic features of the spring waters suggest the occurrence of a shallow aquifer having a Ca2+(Mg2+)-HCO3- composition, relatively low salinity (Total Dissolved Solids _800 mg/L) and a meteoric isotopic signature. Some spring waters close to the oil wells are characterized by relatively high concentrations of NO3- (up to 123 mg/L), unequivocally indicating anthropogenic contamination that adds to the main water-rock interaction processes. The latter can be referred to Ca-Mg-carbonate and, at a minor extent, Al-silicate dissolution, being the outcropping sedimentary rocks characterized by Palaeozoic to Quaternary rocks. Anomalous concentrations of Cl-, SO42-, As, B and Ba were measured in two springs discharging a few hundreds meters from the oil wells and in the Rio Ubierna, possibly indicative of mixing processes, although at very low extent, between deep and shallow aquifers. Gases dissolved in spring waters show relatively high concentrations of atmospheric species, such as N2, O2 and Ar, and isotopically negative CO2 (<-17.7 h V-PDB), likely related to a biogenic source, possibly masking any contribution related to a deep source. The geochemical and isotopic data of this study are of particular importance when a monitoring program will be established to verify whether CO2 leakages, induced by the injection of this greenhouse gas, may affect the quality of the waters of the shallow Hontomín-Huermeces hydrological circuit. In this respect, carbonate chemistry, the isotopic carbon of dissolved CO2 and TDIC (Total Dissolved Inorganic Carbon) and selected trace elements can be considered as useful parameters to trace the migration of the injected CO2 into near-surface environments.

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Acknowledgements The authors acknowledge L. Wicks and B. de Francisco for helping in coral sampling and coral care in the aquaria facilities at SAMS. Thanks to C. Campbell and the CCAP for kind support and help. Scientific party and crew on board the RVs Calanus and Seol Mara, as well as on board the RRS James Cook during the Changing Oceans cruise (JC_073) are greatly acknowledged. Thanks to colleagues at SAMS for their support during our stay at SAMS. We are in debt with A. Olariaga for his help modifying the cylindrical experimental chambers used in the experiments, and C.C. Suckling for assistance with the flume experiment. Many thanks go to G. Kazadinis for preparing the POM used in the feeding experiments. We also thank two anonymous reviewers and the editor for their constructive comments, which contribute to improve the manuscript. This work has been supported by the European Commission through two ASSEMBLE projects (grant agreement no. 227799) conducted in 2010 and 2011 at SAMS, as well as by the UK Ocean Acidification Research Programme's Benthic Consortium project (awards NE/H01747X/1 and NE/H017305/1) funded by NERC. [SS]

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Funded by UK Natural Environment Research Council ESPA project. Grant Number: NE/K010441/1 Afri-Flame

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Acknowledgements We would like to gratefully acknowledge the data provided by SEPA, Iain Malcolm. Mark Speed, Susan Waldron and many MSS staff helped with sample collection and lab analysis. We thank the European Research Council (project GA 335910 VEWA) for funding and are grateful for the constructive comments provided by three anonymous reviewers.

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Date of Acceptance: 25/03/2015

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Mode of access: Internet.

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Climate change is expected to affect the high latitudes first and most severely, rendering Antarctica one of the most significant baseline environments for the study of global climate change. The indirect effects of climate warming, including changes to the availability of key environmental resources, such as water and nutrients, are likely to have a greater impact upon continental Antarctic terrestrial ecosystems than the effects of fluctuations in temperature alone. To investigate the likely impacts of a wetter climate on Antarctic terrestrial communities a multiseason, manipulative field experiment was conducted in the floristically important Windmill Islands region of East Antarctica. Four cryptogamic communities (pure bryophyte, moribund bryophyte, crustose and fructicose lichen-dominated) received increased water and/or nutrient additions over two consecutive summer seasons. The increased water approximated an 18% increase in snow melt days (0.2 degrees C increase in temperature), while the nutrient addition of 3.5g Nm(-2) yr(-1) was within the range of soil N in the vicinity. A range of physiological and biochemical measurements were conducted in order to quantify the community response. While an overall increase in productivity in response to water and nutrient additions was observed, productivity appeared to respond more strongly to nutrient additions than to water additions. Pure bryophyte communities, and lichen communities dominated by the genus Usnea, showed stronger positive responses to nutrient additions, identifying some communities that may be better able to adapt and prosper under the ameliorating conditions associated with a warmer, wetter future climate. Under such a climate, productivity is overall likely to increase but some cryptogamic communities are likely to thrive more than others. Regeneration of moribund bryophytes appears likely only if a future moisture regime creates consistently moist conditions.