Superior selectivity of high-frequency ultrasound toward chorine containing-pharmaceuticals elimination in urine: A comparative study with other oxidation processes through the elucidation of the degradation pathways

Ultrason Sonochem. 2021 Nov 5;80:105814. doi: 10.1016/j.ultsonch.2021.105814. Online ahead of print.ABSTRACTThis work considered the sonochemical degradation (using a bath-type reactor, at 375 kHz and 106.3 W L-1, 250 mL of sample) of three representative halogenated pharmaceuticals (cloxacillin, diclofenac, and losartan) in urine matrices. The action route of the process was initially established. Then, the selectivity of the sonochemical system, to degrade the target pharmaceuticals in simulated fresh urine was compared with electrochemical oxidation (using a BDD anode, at 1.88 mA cm-2), and UVC/H2O2 (at 60 W of light and 500 mol L-1 of H2O2). Also, the treatment of cloxacillin in an actual urine sample by ultrasound and UVC/H2O2 was evaluated. More than 90% of the target compounds concentration, in the simulated matrix, was removed after 60 min of sonication. However, the sono-treatment of cloxacillin in the real sample was less efficient than in the synthetic urine. The ultrasonic process achieved 43% of degradation after 90 min of treatment in the actual matrix. In the sonochemical system, hydroxyl radicals in the interfacial zone were the main degrading agents. Meanwhile, in the electrochemical process, electrogenerated HOCl was responsible for the elimination of pharmaceuticals. In turn, in UVC/H2O2 both direct photolysis and hydroxyl radicals degraded the target pollutants. Interestingly, the degradation by ultrasound of the pharmaceuticals in synthetic fresh urine wa...
Source: Ultrasonics Sonochemistry - Category: Chemistry Authors: Source Type: research