Removal of emerging contaminants in wastewater by sonolysis, photocatalysis and ozonation

Abstract

Three different advanced oxidation processes (AOPs) were applied to investigate the removal of emerging contaminants (ECs) i.e. sulfamethoxazole (SMX), diclofenac (DCF) and carbamazepine (CBZ) in synthetically prepared aqueous solutions. The degradation of these substances was carried out by ozonation, sonolysis and photocatalytic oxidation, as well as by different combinations of these processes. The objectives of this work were to evaluate the removal efficiency of each method and to assess the performance variation of sonolysis in combination with other AOPs. The best performances were achieved by sonocatalysis, which resulted in the removal of the selected pharmaceuticals in the range between 37% and 47%. Under similar experimental conditions, the removal of the selected ECs by single compounds by ozonation was slightly lower than the removal of respective compounds in the mixture. Moreover, pseudo first-order removal rate constants of photocatalytic mineralization were determined as 9.33×10-2, 4.90×10-3, 1.06×10-2 min-1 for SMX, DCF and CBZ, respectively.