Organic pollutants associated with macromolecular soil organic matter: Mode of binding   总被引：2，自引：0，他引：2  

H. H. Richnow  R. Seifert  J. Hefter  M. Link  W. Francke  G. Schaefer  W. Michaelis   《Organic Geochemistry》1997,26(11-12)

A study of ether-linked moieties in macromolecular bound residues of polycyclic aromatic hydrocarbons (PAH) generated in bioremediation experiments was performed using high temperature hydrolysis degradation with subsequent analysis of the products by GC-MS. This hydrolysis reaction was specifically designed to cleave ether bonds including relatively stable diarylether structures. Among the reaction products, aromatic alcohols representing typical microbiologically derived metabolites of PAH were found in addition to natural compounds. Thus, parts of the bound residues appeared to be linked within the macromolecular material by ether bonds. Model experiments with an oxidoreductase enzyme and aromatic alcohols indicate the formation of these ether bonds to be an enzyme-catalysed process.  相似文献   

On the 70 birthday of Wilfried Schönborn     

Günther Friedrich  Heike Zimmermann-Timm  Anita Lange  Rainer Koschel 《Limnologica》2004,34(3):173-175

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Potential impacts of geothermal energy use and storage of heat on groundwater quality,biodiversity, and ecosystem processes     

Christian Griebler  Heike Brielmann  Christina M. Haberer  Sigrid Kaschuba  Claudia Kellermann  Christine Stumpp  Florian Hegler  David Kuntz  Simone Walker-Hertkorn  Tillmann Lueders 《Environmental Earth Sciences》2016,75(20):1391

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The effect of a front on the general circulation—A model study of the Rhine plume area     

Heike Langenberg  Dr. Thomas Pohlmann 《Ocean Dynamics》1994,46(4):341-353

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Direct effects of Daphnia-grazing, not infochemicals, mediate a shift towards large inedible colonies of the gelatinous green alga Sphaerocystis schroeteri     

Heike Kampe  Marie König-Rinke  Jürgen Benndorf 《Limnologica》2007,37(2):137-145

The influence of Daphnia galeata×hyalina grazing and of infochemicals released by the daphnids on the colony size and growth rate of the colonial gelatinous green alga Sphaerocystis schroeteri (Chlorococcales) was investigated in laboratory batch experiments run for 96 h. High zooplankton grazing pressure was exerted by a final concentration of 100 daphnids L⁻¹ in the Daphnia treatments. Infochemicals were obtained by filtration (0.2 μm) of water from D. galeata×hyalina cultures (200 ind. L⁻¹ exposed for 24 h). This filtrate was added to the S. schroeteri cultures in two concentrations corresponding to 7 and 50 daphnids L⁻¹, respectively. The growth rate of S. schroeteri was neither affected significantly by direct Daphnia grazing nor by the presence of Daphnia infochemicals, in comparison to the control. However, the portion of inedible S. schroeteri colonies (diameter>50 μm) increased under direct grazing pressure, whereas the Daphnia infochemicals did not influence the colony size significantly. We conclude that the shift in colony size by direct zooplankton grazing denotes an effective defence mechanism against size selective feeding for colonial gelatinous green algae. This effective defence in combination with unchanged growth rates of the larger colonies (under non-limiting nutrient and light conditions) falsifies the assumption of a trade-off between minimising grazing losses and maximising growth by optimising the colony size.  相似文献   

Methodes astronomiques dans la climatologie historique (Période solaire et climatique de 400 ans)     

František Link  Zděnka Linková 《Studia Geophysica et Geodaetica》1959,3(1):43-61

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Éclairement crépusculaire en lumière jaune 5893 Å     

František Link 《Studia Geophysica et Geodaetica》1958,2(1):47-53

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Ein Beitrag zur Frage der Eutrophierung des Bodensees durch den Alpenrhein     

Dr. E. Wieser  P. Link dipl. Chem 《Aquatic Sciences - Research Across Boundaries》1970,32(2):439-452

Zusammenfassung und Folgerungen Es darf als gesichert gelten, dass die 1961 im Auftrag der Internationalen Gew?sserschutzkommission für den Bodensee ermittelte Jahresfracht von 806 t Gesamtphosphor des Alpenrheins in bezug auf den gel?sten Gesamtphosphor viel zu hoch, in bezug auf die Summe von gel?stem und ungel?stem Gesamtphosphor aber wesentlich zu niedrig liegt. Die aus den Ergebnissen der 1961 er Untersuchung für den Alpenrhein gezogenen Schlussfolgerungen k?nnen daher nur zum Teil richtig sein. Kann durch die andernorts bereits durchgeführten Untersuchungen oder durch neue Abkl?rungen festgestellt werden, dass die aus der adsorptiven Bindung an die Rheinsedimente im Bodensee freigesetzte P-Menge kleiner oder gleich der gel?sten P-Fracht des Alpenrheins ist, so hat, die Forderung auf zus?tzliche Einrichtungen zur P-Elimination (3. Reinigungsstufe oder Simultanf?llung) bei den geplanten oder erstellten mechanisch-biologischen Kl?ranlagen im Einzugsgebiet des Bodensees ihre volle Berechtigung.

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Summary and Conclusions It can be considered an established fact that the yearly load of 806 tons of total phosphorus for the Alpine reaches of the Rhine, determined in 1961 on behalf of the International Commission for the Protection of the Lake of Constance against Pollution, is much too high for the dissolved total phosphorus and significantly too low for the sum of the dissolved and undissolved total phosphorus. The conclusions drawn from the 1961 study of the Alpine regions of the Rhine can therefore be only partially correct. If it can be proven that the amount of phosphorus released from the sediments in the Lake of Constance is smaller or equal to the dissolved phosphorus load of the Alpine part of the Rhine, the demand for additional installations for phosphorus elimination (tertiary treatment of sewage or simultaneous precipitation) for the mechanical-biological sewage treatment plants in the catchment area of the Lake of Constance is fully justified.

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Seasonal dynamics of aggregates and their typical biocoenosis in the Elbe Estuary     

Heike Zimmermann-Timm  Henry Holst  Stefan Müller 《Estuaries and Coasts》1998,21(4):613-621

In 1995, an extensive investigation was carried out in the Elbe Estuary in Germany. Special attention was paid to organisms, including bacteria, amoebae, ciliates, flagellates, rotifers, larvae ofDreissena polymorpha, and nematodes, dispersed in the water column and associated firmly or loosely with different types of aggregates. The abundance, size, and colonization by microorganisms of the aggregates varied during the seasons. The largest aggregates were found during spring and summer, when diatoms, rotifers, and crustaceans were present. The most aggregates were encountered in spring and from summer to autumn. Most of the species observed during the study were more common in pelagic habitats than in benthic ones. However, the presence of ciliates in the groups Hypotrichida and Sessilida as well as as flagellates in the groups Biosoecida, Cercomonadida, Choanoflagellida, Chrysomonadida, Kinetoplastida, and amoebae and some nematodes in the open water depends, upon the availability of surfaces, because they are sessile or poor swimnters, and some flagellates and amoebae need to attach themselves to an object to feed. Most organisms were much more abundant in or on aggregates than in the surrounding water during spring and summer, which indicates that aggregates enhance the habitat and promote the development of the organisms. From spring through autumn, the structure of the community associated with the aggregates is influenced by the pelagic environment. The presence of the species in the benthic community was detected only during summer.  相似文献   

Some consequences of applying lognormal theory to pseudolognormal distributions     

Richard F. Link  George S. Koch Jr. 《Mathematical Geology》1975,7(2):117-128

A logarithmic transformation may be used to improve the efficiency of estimates of the mean when observations follow the lognormal distribution. But if this transformation is applied to observations that follow another distribution, bias may be introduced. We consider some consequences of erroneously applying lognormal estimation theory and demonstrate that biased estimates may be obtained for certain classes of distributions. Illustrations of bias obtained in gold sampling are given.  相似文献