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Abiotischer Abbau und Diffusion chlorierter Lösemittel in Fe2+-haltigen ungestörten Kalksteinen und Tonsteinen

Langsame Diffusionsprozesse von Schadstoffen in geringdurchlässigen wasser-gesättigten Gesteinen sind ein wesentlicher Grund für den beschränkten Erfolg vieler Untergrundsanierungen. Zu den immer noch wichtigsten Schadstoffen im Grundwasser zählen die chlorierten Lösemittel, die trotz jahrzehntelanger Sanierungsanstrengungen inzwischen lange Fahnen im urbanen Raum ausbilden. Eine langsame Diffusion bedingt aber auch lange Aufenthaltszeiten in der Gesteinsmatrix und damit können langsame abiotische Abbaumechanismen zum Tragen kommen, die auf Fe2+-haltige Mineralien wie z.B. Eisensulfide, Magnetit oder Phyllosilikate zurückgehen, und bei der Einschätzung des natürlichen Abbaupotentials berücksichtigt werden sollten. Ziel dieses Vorhabens ist es daher, die Transformation von Tri- und Perchlorethen während der Diffusion in Gesteinsproben geklüfteter Aquifere und Aquitarde zu quantifizieren. Weil die Reaktionsraten der Ausgangssubstanzen sehr wahrscheinlich zu klein sind, um im Labor gemessen werden zu können, liegt der Fokus auf der Bestimmung von Transformations- und Abbauprodukten (bspw. teil-chlorierte Ethene, Azetylen, Ethan). Die Experimente zur reaktiven Diffusion müssen mit intakten Gesteinsproben durchgeführt werden, da beim Zerkleinern reaktive Mineralober-flächen (z.B. bei Quarz und Pyrit) entstehen könnten, die zur Dehalogenierung der Ausgangssubstanzen führen könnten. Im Unterschied zu früheren Studien sollen hier die für die Reaktivität verantwortlichen spezifischen Minerale in der Gesteins-matrix identifiziert werden. Die Ergebnisse sind nicht nur für das Langzeitverhalten von chlorierten Lösemitteln im Grundwasser, sondern generell auch für die Endlagerung von radioaktiven Abfällen oder die chemische Verwitterung (Oxidation) von reduzierten Gesteinen relevant.

Bioökonomie International 2022: Aromatische Plattformchemikalien aus biobasierten nachwachsenden Rohstoffen

Carbon and Chorine Isotope Effect Study to Investigate Chlorinated Ethylene Dehalogenation Mechanisms

Chlorinated ethylenes are prevalent groundwater contaminants. Numerous studies have addressed the mechanism of their reductive dehalogenation during biodegradation and reaction with zero-valent iron. However, despite insight with purified enzymes and well-characterized chemical model systems, conclusive evidence has been missing that the same mechanisms do indeed prevail in real-world transformations. While dual kinetic isotope effect measurements can provide such lines of evidence, until now this approach has not been possible for chlorinated ethylenes because an adequate method for continuous flow compound specific chlorine isotope analysis has been missing. This study attempts to close this prevalent research gap by a combination of two complementary approaches. (1) A novel analytical method to measure isotope effects for carbon and chlorine. (2) A carefully chosen set of well-defined model reactants representing distinct dehalogenation mechanisms believed to be important in real-world systems. Isotope trends observed in biotic and abiotic environmental dehalogenation will be compared to these model reactions, and the respective mechanistic hypotheses will be confirmed or discarded. With this hypothesis-driven approach it is our goal to elucidate for the first timdehalogenation reactions.

GTS Bulletin: WOSN01 ESNO - Warnings (details are described in the abstract)

The WOSN01 TTAAii Data Designators decode as: T1 (W): Warnings T1T2 (WO): Other A1A2 (SN): Sweden (Remarks from Volume-C: NilReason)

Lipid class composition of mesopelagic fish from the North Atlantic Ocean and the Western Mediterranean Sea

Mesopelagic fish collected during 3 field campaigns in 2020 were analysed for their lipid content. The sampling was conducted on 5 main locations; 2 stations in the Western Mediterranean Sea (September/October), 4 stations in the North Atlantic off the Iberian Peninsula (October), 4 stations in the Irminger Sea (July), 5 stations in the Iceland Basin (July) and 4 stations in the Northern Norwegian Sea (May). The fish were collected at distinct depth intervals, with different trawl types depending on the vessel. The database consists of 28 mesopelagic fish species belonging to 9 families and 5 genera. For each record, length and wet weight of the fish analysed is recorded with the wax ester (WE), triacylglycerol (TAG) and phospholipid (PL) values as % of total lipids (TL). Each data record is associated with information on the sampling location, geographic coordinates, month and year of sample collection, sampling gear and depth, taxonomic ranks (phylum, class, order, family), and number and replicates analysed. The lipids were extracted following Folch's extraction method (Folch et al. 1957), which was implemented on whole fish or a weighted sub-sample of a homogenized whole fish. Individual lipid classes were separated by Thin Layer Chromatography (TLC). A lipid sample was spotted onto silica-coated quartz rods, (chromarods; SES GmbH) and the lipid classes separated by development in two solvent systems: hexane/diethyl ether/acetic acid (60:17:0.2, by volume) followed by hexane/diethyl ether (96:4 vol/vol). The analysis was performed using an Iatroscan MK 5 TLC-FID analyser.

GTS Bulletin: WODL45 EDZW - Warnings (details are described in the abstract)

The WODL45 TTAAii Data Designators decode as: T1 (W): Warnings T1T2 (WO): Other A1A2 (DL): Germany (Remarks from Volume-C: STRONG WIND, GALE AND STORM WARNINGS FOR GERMAN BIGHT AND BALTIC SEA (IN GERMAN/ENGLISH))

GTS Bulletin: WOEN69 EDZW - Warnings (details are described in the abstract)

The WOEN69 TTAAii Data Designators decode as: T1 (W): Warnings T1T2 (WO): Other A1A2 (EN): Northern Europe (Remarks from Volume-C: WARNING FOR NORTH SEA AND BALTIC SEA (IN ENGLISH))

GTS Bulletin: WOEN88 EDZW - Warnings (details are described in the abstract)

The WOEN88 TTAAii Data Designators decode as: T1 (W): Warnings T1T2 (WO): Other A1A2 (EN): Northern Europe (Remarks from Volume-C: WARNING FOR GERMAN BIGHT (IN ENGLISH))

GTS Bulletin: WOBQ61 EDZW - Warnings (details are described in the abstract)

The WOBQ61 TTAAii Data Designators decode as: T1 (W): Warnings T1T2 (WO): Other A1A2 (BQ): Baltic Sea area (Remarks from Volume-C: WARNING FOR THE BALTIC SEA (IN ENGLISH))

GTS Bulletin: WODN41 EKMK - Warnings (details are described in the abstract)

The WODN41 TTAAii Data Designators decode as: T1 (W): Warnings T1T2 (WO): Other A1A2 (DN): Denmark (Remarks from Volume-C: NilReason)

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