J. Khan, Xuexiang He, N. S. Shah
Sep 15, 2014
Citations
4
Influential Citations
399
Citations
Quality indicators
Journal
Chemical Engineering Journal
Abstract
Abstract Degradation of atrazine was investigated under UV-254 nm irradiation, alone or in combination with peroxides, i.e., hydrogen peroxide, persulfate (PS) or peroxymonosulfate (PMS). UV/PS was found to be the most efficient process in this study, which was probably due to its higher radical quantum yield under UV irradiation, considering atrazine’s comparable second order rate constant of 2.59 × 10 9 M −1 s −1 and 2.25 × 10 9 M −1 s −1 with sulfate radical and hydroxyl radical, respectively. The pH values showed no significant effect on direct photolysis of atrazine, with observed UV fluence based pseudo-first-order rate constant ( k obs ) of 7.59 × 10 −4 , 7.73 × 10 −4 and 6.72 × 10 −4 cm 2 mJ −1 at pH 3.0, 5.7 and 11.0, respectively. Performance of UV/H 2 O 2 and UV/PMS were more independent of initial pH values while that of UV/PS appeared to be more efficient at neutral pH condition. UV/PS was observed as a less energy consumption process. Eight new degradation by-products were identified in this study, namely, 2-chloro-4-acetamido-6-(2-hydroxy-isopropylamino)-s-triazine (CDHT), 2-hydroxy-4-(2-hydroxy-ethylamino)-6-isopropylamino-s-triazine (ONIT), 2-chloro-4-vinylamino-6-isopropylamino-s-triazine (CVIT), 2-hydroxy-4-vinylamino-6-(2-hydroxy-isopropylamino)-s-triazine (OVHT), 2-hydroxy-4-acetamido-6-isopropenylamino-s-triazine (ODPT), 2-hydroxy-4-(2-hydroxy-ethylamino)-6-vinylamino-s-triazine (ONVT), 2-hydroxy-4-(2-hydroxy-ethylamino)-6-methylamino-s-triazine (ONMT) and 2-chloro-4-vinylamino-6-amino-s-triazine (CVAT). Potential degradation pathways were further proposed.