Efficiency increased advanced oxidation processes by persalts for the elimination of pharmaceuticals in waterbodies: a short review

Abstract

To achieve complete elimination of anthropogenic micropollutants in aquatic environments, advanced oxidation processes are intensively researched as remedies and potential advanced purification stages in wastewater treatment facilities. Persalts, like persulfates, percarbonates and periodates, have been investigated as potential accelerators or enhancers of these processes. This short review provides an overview of the efficiency of the persalts demonstrated for the degradation of the seven most frequently occurring pharmaceuticals in the aquatic environment: carbamazepine, ciprofloxacin, diclofenac, ibuprofen, metoprolol, paracetamol and sulfamethoxazole. While persulfates were the most commonly used, all persalts increase the effectiveness of the degradation of the pharmaceutical contaminants by increasing the formation of hydroxyl radicals, especially in the case of sodium percarbonate. Persalts are efficiently activated through UVC irradiation. The generated hydroxyl radicals are the main factor for product formation and hence dominate the chemical structures of the transformation products. From the ecotoxicological perspective, the use of persalts causes little or no hazard, if the conditions are such that acidification can be neglected. While they are transformed to stable anions on reaction, the resulting transformation products of the anthropogenic micropollutants were predicted by quantitative structure activity relation analysis to possess lower ecotoxicity than the initial drugs.