Carbamazepine was previously reported to be recalcitrant in surface waters [20] and in water/sediment systems [21]. Even though no substantial dissipation of carbamazepine was observed in this study, the occurrence of its TP carbamazepine-10,11-epoxide toward the end of the incubation period points to the onset of transformation (Fig. 3).Some indications on microbial transformation of carbamazepine have also been observed in additional incubation experiments by Radke and Maier (unpublished data).