HYDROGEN PEROXIDE-ASSISTED LOW PRESSURE UV PHOTODEGRADATION OF PROMETRYN IN AQUEOUS SOLUTION

Prometryn (PRT, 2,4-bis(isopropylamino)-6-methylthio-1,3,5-triazine) was photolyzed (lambda = 254 rim) by low pressure UV/H2O2 process under a variety of solution conditions including the concentration of hydrogen peroxide (H2O2), initial concentration of PRT, pH values, light intensity and different water. The experiment results show that rate constants of PRT degradation are almost same under different initial concentration of PRT. However, rate constants of PRT degradation were very different when PRT solutions were prepared by different water. In this study, the time-dependent degradation profiles of PRT were successfully fitted by the first-order equation and the kinetics parameters were determined. In addition, PRT by low pressure UV/H2O2 treatment yielded several organic by-products which were identified including 2, 4-bis(isopropylamino)-s-triazine, 2-hydroxy-4,6-bis(isopropylamino)-s-triazine, 2-methylthio-4-amino-6-isopropylamino-s-triazine, 2-hydroxydesisopropylatrazine and 2-hydroxy-4-acetamido6-ethylamino-s-triazine. Then PRT degradation pathway was proposed.