Synergistic effects of ultrasounds in the sonoelectrochemical oxidation of pharmaceutical carbamazepine pollutant

The synergistic effects were evaluated during the oxidation of carbamazepine using a sono-electrochemical process. The sono-electrochemical oxidation was performed using two types of experimental units (having 1 L and 100 L of working volume, respectively) and containing one anode (Ti/PbO2) and one cathode (Ti). Different operating parameters, including power of ultrasounds, current intensity and reaction time were investigated. The degree of synergy increased when the current intensity decreased, whereas it increased with the power of ultrasounds imposed. The highest value of the synergy degree (33%) was recorded for the lowest current intensity (1.0 A) and the highest power of ultrasounds (40 W). Likewise, the benefits of ultrasound were observed during a long-term period of treatment of CBZ (30 days of experiments without interruption). A relatively high degradation rate was recorded using the sono-electrochemical process (99.5%) (at I = 1 A, P = 40 W), compared to a percentage of CBZ degradation of 91% recorded during electrolysis alone (at I = 1 A, P = 0 W). Likewise, the scanning electron microscopy views and the measurements of the electrochemical impedance spectroscopy (EIS) revealed that there are not impurities deposited on the surface of electrode in the present of ultrasounds.