DISINFECTION IN WASTEWATER TREATMENT PLANTS: ISOLATION AND CHARACTERIZATION OF TRAMADOL PARENT BY PRODUCTS AND EVALUATION OF THEIR TOXICITY

During the last years, the widespread occurrence of personal care products, pesticides and stimulating drugs in water has gained much attention, especially for the evaluation of the environmental risk based on the calculation of the Predicted Environmental Concentrations (PEC) obtained from consumption data [1]. Data on the occurrence of these emerging pollutants were reported by Xing et al. (2018) in sewage treatment plant influents, effluents and sludge in many countries of the world, where they were found until to hundreds ng/L concentrations [2]. Often the products obtained by disinfection treatment could be more toxic than parent compounds especially using the chlorination process [3]. Moreover, the potential risk posed by these pollutants could be increased by their susceptibility to produce photo-transformation products [4]. Tramadol is a synthetic, centrally acting analgesic agent used for the relief of acute and chronic pain, which has been used in both human and veterinary medicine. Recent papers have reported a study on the increasing tramadol utilization associated to the mortality over the past 15 years in the UK, highlighting the high toxicity of this drug [5]. Our research is focused on the evaluation of the environmental effects of tramadol and its transformation products, mimicking the most common experimental conditions in wastewater treatment plants. After disinfection treatment, the main transformation products have been isolated and characterized by NMR and ESI-MS analyses. Furthermore, in order to evaluate the environmental eects of products, aquatic acute and chronic toxicity have been tested on Brachionus calyciorus and Ceriodaphnia dubia as well as their mutagenesis and genotoxicity tested on bacterial strains.