EB-radiolysis of carbamazepine: in pure-water with different ions and in surface water

The electron beam (EB) radiolysis characteristics of carbamazepine (CBZ) in pure-water with different ions and that in surface water were studied in this paper. It suggested that the ·OH, ·H and e aq − all played roles on CBZ EB degradation, and the ·OH played the vital role. Acidic solution was favorable for CBZ degradation, while alkaline environment inhibited it. HSO 4 – and SO 3 2− enhanced the CBZ degradation, but CO 3 2− , NO 2 − , NO 3 − NH 4 + and Cl − inhibited. In surface water, the EB-radiolysis was an effective way to degrade CBZ; and CBZ might evolve in three different ways during EB radiation: reduction by e aq − and ·H (intermediate 10,11-dihydrocarbamazepine (I)), oxidization by ·OH (intermediates 10,11-dihydro-10-11-expoxycarbamazepine (II) and 2( 3 )-hydroxycarbamazepine (III)) and hydration into 10,11-dihydro-10-hydroxycarbamazepine (IV) and finally the intermediates were all mineralized into CO 2 , H 2 O, N 2 and NH 4 + . All the results contribute to study the EB-radiolysis of pharmaceuticals in surface water.