Brevetoxins induce toxicity at very low concentration, and their elimination is critical to protect the environment and human health. The degradation of Brevetoxin-3 (PbTx-3) in aqueous solution by advanced oxidation processes (AOPs): Fenton and ultrasound was studied. This study investigates the sonolytic degradation of 4.5 ppm of Pbtx-3 at 665 KHz under operational power of 500W and at neutral pH which decreases during the ultrasonic irradiation. In all the reactions, Brevetoxin solutions prepared, were taken from a stock solution and were gently purged with oxygen or argon for 5 min prior to irradiation. A kinetic study of PbTx-3 degradation under argon, oxygen and air atmospheres showed a pseudo-first-order reaction kinetics. The effect of Fe (II) on H2O2 accumulation during ultrasound reaction was investigated and showed a decrease of H2O2 concentration which explains the formation of hydroxyl radicals that enhance the degradation of the pollutant. Also, the degradation of the toxin was studied by different systems: PbTx-3/US; PbTx-3/H2O2/US; PbTx-3/Fe/US; PbTx- 3/Fe/H2O2/US. The last system combining Fenton and ultrasound enhanced remarkably the rate of degradation of PbTx-3, and yields to its complete removal in less than 15 min.
