Degradation of benzodiazepines using water falling film dielectric barrier discharge reactor

Abstract

Classical methods of wastewater treatment are often not suitable for the treatment of pharmaceutical waste. The previous studies have shown that the use of the advanced oxidation procedures (AOP) can lead to a more effi­cient degradation of various biologically active compounds, which are active pharmaceutical ingredients of applied drugs. The aim of this paper is the appli­cation of the plasma technology on the degradation of a two active pharma­ceutical ingredients (APIs, diazepam and alprazolam) and the finished products (Bensedin^® and Ksalol^®) using the dielectric barrier discharge (DBD) reactor for AOP. We studied the degradation rate of these pharmaceuticals, depending on the number of passes through the reactor. This degrad­ation method was efficient 61 % for diazepam and 95 % alprazolam. We also examined the inf­luence of the pH adjustment between the passes of APIs through the DBD reac­tor. The degradation rate of APIs and the finished products was monitored by the high performance liquid chromatography (HPLC) technique, using a photo­diode array detector. The concentration of the dissolved ozone was determined using the iodometric procedure.