Tusnelda E. Doll

Fate of pharmaceuticals-photodegradation by simulated solar UV-light

The fate of pharmaceuticals in surface waters under solar irradiation was investigated. Photodegradation of pharmaceuticals caused by sun irradiation may be of major significance in the natural elimination process. Based on a data compilation from the literature, the lipid lowering agent metabolite clofibric acid, the iodinated X-ray contrast media iomeprol, which contribute to the adsorbable organic halogen compounds, and the antiepileptic drug carbamazepine were selected. The irradiation experiments were carried out in batch experiments with simulated UV-sunlight. The photodegradation of the pharmaceuticals showed a pseudo-first-order kinetics. The objective of this investigation was to demonstrate that the extent of photoinduced degradation of pharmaceuticals can vary significantly for the different pharmaceuticals and it strongly depends on the water constituents present in solution. The influences of different initial pharmaceutical concentrations, the presence of other pharmaceuticals like carbamazepine or clofibric acid and the presence of natural organic matter on the photochemical degradation rate of pharmaceuticals in aqueous solutions were investigated. Analyses of the pharmaceuticals and their photodegradation products were carried out by high performance liquid chromatography with diode-array and fluorescence detection.

XENOBIOTIC PHARMACEUTICALS IN WATER AND METHODS TO PREVENT THEIR APPEARANCE IN DRINKING WATER

The aim of this work was to investigate the sun light induced photodegradation as well as the photocatalytic degradation of pharmaceuticals and X-ray diagnostic agents (PhaDAs), and to follow their degradation pathways. The influence on the photolytic and photocatalytic degradation of the selected PhaDAs in the absence and presence of natural organic matter was investigated. Technical systems suitable for photocatalytic degradation and adsorption were developed and their applicability was checked. The advanced oxidation processes and adsorption experiments led to promising data for the elimination of the PhaDAs.