Degradation of 2,4-dinitrophenol by combining sonolysis and different additives

Based on the effects of various additives on ultrasonic degradation of 2,4-dinitrophenol (DNP) in aqueous solution, the degradation mechanisms and reaction kinetics of DNP in different processes were proposed. The results showed that some additives, such as CuO, CCl4, O3, NaCl and KI, were favorable for DNP sonochemical degradation. On the contrary, DNP degradation efficiency was restrained by Na2CO3, indicating that OH radicals oxidation played an important role in DNP ultrasonic removal. The significant increases in DNP degradation in US/CuO/H2O2, US/CCl4 and US/O3 systems were also related to the intermediates formed during the reactions, such as HO2/O2− radicals, chlorine-containing radicals and HClO. In addition, DNP ultrasonic removal was observed to behave as pseudo-first-order kinetics under different experimental conditions tested in the present work.