Ultrasonic assisted electrochemical degradation of malachite green in wastewater

Abstract

An advanced oxidation method combining ultrasonic (US) and electrochemical (EC) for degrading malachite green wastewater in batches was discovered. The performance of the system can be judged by quantitatively measuring the degradation rate of malachite green under different electrode materials, electrolytes, voltages and powers. The results show that the highest degradation of malachite green was obtained, reaching up to 94.92%, when the voltage was 20 V, ultrasonic power was 300 W and electrolyte solution was 15.0 g/L Na2SO4 under the condition that the ruthenium-iridium plated titanium electrode was used as the anode and graphite as the cathode. The ultrasonic electrochemical process conforms to the characteristics of pseudo-first-order reaction kinetics. Compared with other methods, ultrasonic electrochemical method is more cost-effective and environmentally friendly. Finally, the possible degradation process of malachite green is inferred, including oxidation and N-demethylation.