500 Naturwissenschaften und Mathematik
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- 2010 (2) (entfernen)
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- Biotransformation (1)
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- Flusssediment (1)
- ICM (1)
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- Mesobenthos (1)
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- benthos (1)
Investigating the environmental fate of iodinated X-ray contrast media in the urban water cycle
(2010)
Iodinated X-ray contrast media (ICM) are a group of emerging contaminants which have been detected at elevated concentrations in the aquatic environment. These compounds are excreted unmetabolized into hospital wastewater, and eventually treated at wastewater treatment plants (WWTPs). The removal of ICM in WWTPs has not been very effective and therefore the ICM enter the aquatic environment via WWTP effluent discharges. Research has investigated the removal of selected ICM via abiotic and biotic processes, however limited work has attempted to determine the fate of these compounds once released into the environment. This thesis investigates the biotransformation of four selected ICM (diatrizoate, iohexol, iomeprol, and iopamidol) in aerobic soil-water and sediment-water systems as well as in different environmental matrices. Iohexol, iomeprol and iopamidol were biotransformed to several TPs in the aerobic batch systems, while no biotransformation was observed for the ionic ICM, diatrizoate. In total 34 biotransformation products (TPs) of the three non-ionic ICM were identified. The combination of semi-preparative HPLC-UV, hybrid triple quadrupole-linear ion trap mass spectrometry (Qq-LIT-MS) was found to be an accurate approach for the structural elucidation of ICM TPs. The ICM TPs resulted in microbial transformation occurring at the side chains of the parent ICM, with the iodinated aromatic ring unmodified.
Diese Arbeit untersucht die Biozönosen kontaminierter schlammig-schluffiger Sedimente in Stillwasserzonen großer Flüsse. Diese feinkörnigen und weichgründigen Sedimente beherbergen Lebensgemeinschaften, die zu einem großen Teil als Meiozoobenthos angesprochen werden und im Vergleich zu den Makrozoobenthos-Biozönosen grobkörniger und hartgründiger Fließgewässer und den Meiobenthos-Biozönosen der Küsten-, Tiden- und Ästuarbereiche bisher nur unzulänglich untersucht worden sind. Da die feinkörnigen Sedimente eine große Kapazität zur Schadstoffbindung haben, sind sie generell von großem ökotoxikologischen und wasserbaulichen Interesse. Ziele der Arbeit: (1) Entwicklung einer quantitativen Methode zur Bestandserfassung. (2) Untersuchung der lokalen und saisonalen Dynamik der benthischen Metazoen- Biozönose in Schluffsedimenten. (3) Ermittlung der Einflüsse chemischer und physikalischer Sedimenteigenschaftenrnauf die Biozönosen. (4) Beschreibung der Resilienz der Benthos-Biozönosen schluffiger Sedimente; Einfluss katastrophaler Ereignisse.