Removal of Pharmaceutically Active Compounds in Sequencing Batch Reactor

Abstract

Biological treatment efficiency of six pharmaceutical compounds (acetazolamide, metronidazole, opipramol, piracetam, salicylamide and tinidazole) was evaluated using lab-scale Sequencing Batch Reactor (SBR). Comparative biological degradation processes of two types of activated sludge from municipal and pharmaceutical industry sewage treatment plants were examined. Three different organic loadings (0.05 g COD/g MLSS·d, 0.1 g COD/g MLSS·d and 0.2 g COD/g MLSS·d) and reaction time on the efficiency of Active Pharmaceutical Ingredient (API) decomposition were examined. Chemical oxygen demand, non-purgeable organic carbon as well as ammonium nitrogen contents were monitored by standard methods. Percentage of API decomposition was analysed by High Performance Liquid Chromatography (HPLC). The overall API removal efficiency was strictly dependent on the type of activated sludge origin. The main biodegradation products were identified using HPLC-MS, 1 H NMR and 13 C NMR methods as e.g. ({4-[3-(5H-dibenzo[b,f]azepin-5-yl]piperazin-1-yl}methanamine) and (2-amino-1,3,4-thiadiazol-5-sulfonamide) for opipramol and acetazolamide respectively.