Ozone treatment for pesticide removal from carrots: Optimization by response surface methodology

The present study aimed to optimize ozone (O₃) treatments, as gas and dissolved in water, to remove difenoconazole and linuron in carrots. We employed a central composite design to study three variables governing the efficacy of treatments: O₃ concentration, temperature and treatment time. The temperature did not influence the efficacy of treatments. The removal percentage of pesticides increases with increases in ozone concentration and the time of treatment. O₃ application promoted the removal of more than 80% of pesticides when the roots were exposed for approximately 120min at 5 and 10mgL^-1, respectively, in treatments with O₃ as gas and dissolved in water. After storage, pesticide removal was higher than 98% for difenoconazole and 95% for linuron. The degradation products from the pesticides resulting from treatment were monitored, but none were found. This is the first report demonstrating the removal of difenoconazole and linuron from carrots by ozone.