Molecular and biogeochemical data were combined to determine the origin of CH4 in surface sediment of an eutrophic alpine lake (Lake Bled, NW Slovenia). The contribution of “fresh” autochthonous lipids in sedimentary organic matter (OM) decreased from 62% at the surface to 41% at the depth of 20 cm. The contribution of lipids of bacterial origin was more pronounced at the surface, comprising 13%. TRFLP analysis of 16S rRNA sequences of bacterial and archaeal community members suggested that larger sediment depth dependent changes occurred in the archaeal community. The majority of archaeal sequences belonged to Euryarchaeota. In the upper 2 cm, hydrogenotrophs mostly Methanomicrobiaceae were dominant. In deeper sediment, archaeal sequences comprised mostly those of unknown affiliation with Euryarchaeota, Thermoplasmatales and related linkages, and only 21% of the hydrogenotrophic methanogenic archaea were detected. The biogeochemical processes and archaeal community support the hypothesis that hydrogenotrophic methanogenesis is the dominant pathway in alpine Lake Bled sediment despite low temperature and the prevalence of“fresh” autochthonous derived OM.
A reflection on the last report from the European Commission on the application and effectiveness of the Directive on Strategic Environmental Assessment (SEA) is provided. It covers the inadequacies of the approval/permitting context of SEA, which appears to be increasingly applied by a significant number of Member States in recent years. A viewpoint is provided on the main deficiencies of such praxis. As a practical defence of the planning context of SEA, the authors propose that the EC should consider a clear recommendation to Member States to cease performing SEA in the approval/permitting context until proper amendments to the SEA Directive are made and implemented.
I-129 is gradually released into the from reprocessing plants (Sellafield, La Hague) into the atmosphere and marine environment. Followed by physical transfer to air or aqueous media under the influence of chemical and biological processes, Iodine is excreted from marine and terrestrial environment into the atmosphere in the organic form (mainly as methyl iodide), as a result of the action of microorganisms. Under the influence of sunlight, the releasable organic iodine decomposes to inorganic iodine compounds, and then enters the marine and terrestrial environment to the processes of wet and dry deposition. We sampled seawater and algae in Žusterna, Portoroz and thick Rtič, and mussels in Koper, Piran-Seca and Strunjan and marine sediment sampled in Koper and Piran Bay. 129I/127I isotopic ratio is in the range 0.8 3.0 • Tues 10-08 to seawater, 0:06 to 0:35 • 10-08 for sediment, 0:05 to 0:10 • 10-08 for Adriatic Bračič and 0.3 to 0.9 • 10-08 for mussels Mytilus galloprovincialis. Our results are in the same range as the data for Antlantsko sea on the west coast of Ireland and at the same time, these are the first data for 129I content and isotopic ratio 129I/127I the ecosystem in the Mediterranean Sea, which is insulated from direct discharges into the sea 129I.
Chromium (Cr) conversion coatings are used as decorative finishes and to improve the corrosion protection and strengthen the wear resistance of metallic surfaces. Cr electroplating frequently involves the use of Cr(VI). To reduce environmental impacts, several EU directives restricted its use to threshold values of 0.1 % Cr(VI) by weight per homogenous material in vehicles, and 1000 mg kg-1 of Cr(VI) in electronic and electrical equipment. There are only few analytical procedures reported that comply with legislative demands. In our work a selective, quantitative and sensitive analytical procedure for determination of Cr(VI) in the corrosion protection coatings was developed. The investigation was performed on metallic plates homogenously treated by chromium conversion or hard chrome coatings on copper or zinc electroplated steel surfaces. An alkaline solution (pH 12) was used for ultrasonic extraction of Cr(VI). Speciation analysis was performed by anion-exchange HPLC-ICP-MS. Species interconversions during the analytical procedure were followed using enriched isotopic solutions of 50Cr(VI) and 53Cr(III). To prevent Cr(III) oxidation, TRIS, EDTA or MgCl2 were added along with a double isotopically enriched spike and extractions performed over different time periods. Under optimal conditions that prevent any species interconversion (30 min ultrasonic extraction at 70 °C using 2 % NaOH + 3 % Na2CO3 + MgCl2 as extraction agent), six consecutive extractions were necessary to quantitatively extract Cr(VI) from the protective layers, while its content was determined by speciated isotope dilution ICP-MS.
Benzodiazepine derivatives are prescribed in large quantities globally and are potentially new emerging environmental contaminants. Unfortunately, a dearth of data exists concerning occurrence, persistence and fate in the environment. This paper redresses this by reviewing existing literature, assessing the occurrence of selected benzodiazepine anxiolytics (diazepam, oxazepam and bromazepam) in wastewater influent and effluent and surface water from Slovenia, evaluating their removal during water treatment and identifying the transformation products formed during water treatment.