Degradation of brevetoxin-3 by the combined process Fenton and ultrasound

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.