| Title | Degradation of herbicides (ametryn and isoproturon) during water disinfection by means of two oxidants (hypochlorite and chlorine dioxide) |
| Abstract | The paper reports the results of an investigation aimed to find out the number and the chemical structures of byproducts which form during the reactions occurring in aqueous solution between two very common disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO2), and two herbicides widely used in agriculture and frequently found in groundwaters: ametryn and isoproturon. Under controlled experimental conditions [T=20 degrees C, pH=7, reaction-time = 48h, herbicide/disinfectant molar ratios: 0.05 and 0.05x10(-2)], ametryn reactions with chlorine dioxide much slower than with sodium hypochlorite, whereas the opposite trend has been observed for isoproturon. In any case, however, the higher the reagents concentration the faster the reactions. As for reaction byproducts, they have been detected by HPLC and identified by HPLC-MS. In particular, ametryn (R-S-CH3) reaction with NaClO gives rise to the consecutive formation of four derivatives: the sulphoxide (R-SO-CH3), the sulphone (R-SO2-CH3), the sulphonate ester (R-O-SO2-CH3) and its hydrolysis product (R-OH). Within the fixed reaction time (48h), ametryn reaction with ClO2 forms only the sulphoxide derivative (R-SO-CH3). As for isoproturon, it reacts with both oxidants forming aromatic-ring substituted derivatives. In particular, during the reactions with NaClO and ClO2, four and two (chlorinated and/or hydroxylated) derivatives are respectively formed. (C) 1997 IAWQ. Published by Elsevier Science Ltd. |
| Source | Water science and technology 35 (4), pp. 129–136 |
| Keywords | disinfectionhypochloritechlorine dioxideisoproturonametryndisinfection by-productsHPLC-MS |
| Journal | Water science and technology |
| Editor | IWA Publishing, London, |
| Year | 1997 |
| Type | Articolo in rivista |
| DOI | 10.1016/S0273-1223(97)00018-8 |
| Authors | Lopez, A; Mascolo, G; Tiravanti, G; Passino, R |
| Text | 323828 1997 10.1016/S0273 1223 97 00018 8 ISI Web of Science WOS A1997WM81500018 disinfection hypochlorite chlorine dioxide isoproturon ametryn disinfection by products HPLC MS Degradation of herbicides ametryn and isoproturon during water disinfection by means of two oxidants hypochlorite and chlorine dioxide Lopez, A; Mascolo, G; Tiravanti, G; Passino, R Consiglio Nazionale delle Ricerche CNR The paper reports the results of an investigation aimed to find out the number and the chemical structures of byproducts which form during the reactions occurring in aqueous solution between two very common disinfectants, sodium hypochlorite NaClO and chlorine dioxide ClO2 , and two herbicides widely used in agriculture and frequently found in groundwaters ametryn and isoproturon. Under controlled experimental conditions T=20 degrees C, pH=7, reaction time = 48h, herbicide/disinfectant molar ratios 0.05 and 0.05x10 2 , ametryn reactions with chlorine dioxide much slower than with sodium hypochlorite, whereas the opposite trend has been observed for isoproturon. In any case, however, the higher the reagents concentration the faster the reactions. As for reaction byproducts, they have been detected by HPLC and identified by HPLC MS. In particular, ametryn R S CH3 reaction with NaClO gives rise to the consecutive formation of four derivatives the sulphoxide R SO CH3 , the sulphone R SO2 CH3 , the sulphonate ester R O SO2 CH3 and its hydrolysis product R OH . Within the fixed reaction time 48h , ametryn reaction with ClO2 forms only the sulphoxide derivative R SO CH3 . As for isoproturon, it reacts with both oxidants forming aromatic ring substituted derivatives. In particular, during the reactions with NaClO and ClO2, four and two chlorinated and/or hydroxylated derivatives are respectively formed. C 1997 IAWQ. Published by Elsevier Science Ltd. 35 Degradation of herbicides ametryn and isoproturon during water disinfection by means of two oxidants hypochlorite and chlorine dioxide 24.pdf Articolo in rivista IWA Publishing 0273 1223 Water science and technology Water science and technology Water science and technology. Water sci. technol. antonio.lopez LOPEZ ANTONIO giuseppe.mascolo MASCOLO GIUSEPPE |
