Application of Ultraviolet and Ultrasound Irradiation for the Degradation of Pyridine in Wastewater: A Comparative Study

摘要

The photochemical and sonochemical degradation of aqueous solutions of pyridine, a common refractory pollutant in wastewater effluents, have been investigated by means of ultraviolet (UV), ultrasound (US), UV/H2O2, and US/H2O2 irradiation processes. The pure photochemical process were demonstrated to be efficient for degradation of low initial concentrations of pyridine (10 ppm). Sonochemical degradation proceeded very slowly, leading to less than 53% of pyridine removal after 200 min. The degradation efficiency was increased with increasing H2O2 concentration; however, the marginal benefit became decreasing with further increasing of H2O2 due to the scavenging effect of excess H2O2. The kinetics of photochemical and sonochemical degradation of pyridine were found to follow a first-order rate law. A possible degradation pathway for pyridine was also proposed.