Ozonation of carbamazepine in drinking water: identification and kinetic study of major oxidation products.

Kinetics and product formation of the anti-epileptic drug carbamazepine (CBZ) were investigated in lab-scale experiments during reactions with ozone and OH radicals. Ozone reacts rapidly with the double bond in CBZ, yielding several ozonation products containing quinazoline-based functional groups. The structures for three new oxidation products were elucidated using a combination of mass spectrometric and NMR techniques.

Oxidation of pharmaceuticals during water treatment with chlorine dioxide.

The potential of chlorine dioxide (ClO2) for the oxidation of pharmaceuticals during water treatment was assessed by determining second-order rate constants for the reaction with selected environmentally relevant pharmaceuticals. Out of 9 pharmaceuticals only the 4 following compounds showed an appreciable reactivity with ClO2 (in brackets apparent second-order rate constants at pH 7 and T = 20 degrees C): the sulfonamide antibiotic sulfamethoxazole (6.7 x 10(3) M(-1) s(-1)), the macrolide antibiotic roxithromycin (2.

Oxidation of pharmaceuticals during ozonation of municipal wastewater effluents: a pilot study.

To reduce the release of pharmaceuticals and endocrine disruptors into the aquatic environment or to remove them from wastewater intended for direct or indirect reuse, the application of advanced wastewater treatment may be required. In the present study, municipal wastewater effluents were treated with ozone (O3) in a pilot-scale plant consisting of two bubble columns. The investigated effluents, which varied in suspended solids concentrations, comprised an effluent of conventional activated sludge treatment (CAS), the same effluent dosed with 15 mg of TSS L(-1) of activated sludge (CAS + SS), and the effluent of a membrane bioreactor pilot plant (MBR).

Removal of estrogenic activity and formation of oxidation products during ozonation of 17alpha-ethinylestradiol.

This study investigated the oxidation of the oral contraceptive 17alpha-ethinylestradiol (EE2) during ozonation. First, the effect of ozone (O3) on the estrogenic activity of aqueous solutions of EE2 was studied using a yeast estrogen screen (YES). It could be shown that O3 doses typically applied for the disinfection of drinking waters were sufficient to reduce estrogenicity by a factor of more than 200.

Oxidation of pharmaceuticals during ozonation and advanced oxidation processes.

This study investigates the oxidation of pharmaceuticals during conventional ozonation and advanced oxidation processes (AOPs) applied in drinking water treatment. In a first step, second-order rate constants for the reactions of selected pharmaceuticals with ozone (k(O3)) and OH radicals (k(OH)) were determined in bench-scale experiments (in brackets apparent k(O3) at pH 7 and T = 20 degrees C): bezafibrate (590 +/- 50 M(-1) s(-1)), carbamazepine (approximately 3 x 10(5) M(-1) s(-1)), diazepam (0.75 +/- 0.