TY - JOUR
T1 - Comparative studies of various iron-mediated oxidative systems for the photochemical degradation of endosulfan in aqueous solution
AU - Shah, Noor S.
AU - He, Xuexiang
AU - Khan, Javed Ali
AU - Khan, Hasan M.
AU - Boccelli, Dominic L.
AU - Dionysiou, Dionysios D.
N1 - Funding Information:
D.D. Dionysiou and X. He are grateful to the Cyprus Research Promotion Foundation for providing partial financial support for this project through Desmi 2009–2010 which was co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation (Strategic Infrastructure Project ΝΕΑ ΥПΟΔΟΜΗ/ΣΤΡΑΤΗ/0308/09). The authors would like to acknowledge the Higher Education Commission (HEC), Islamabad, Pakistan for partially funding this project through an International Research Support Initiative Program (IRSIP). D.D. Dionysiou also acknowledges support from the University of Cincinnati through a UNESCO co-Chair Professor position on “Water Access and Sustainability”.
Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/6/15
Y1 - 2015/6/15
N2 - This study investigated iron-mediated oxidative processes for the photochemical degradation of endosulfan, a chlorinated insecticide and central nervous system disruptor. At UV fluence of 360 mJ/cm2, 52.4% and 32.0% removal of 2.45 μM initial endosulfan was observed by UV/Fe3+ and UV/Fe2+ processes, respectively, at an initial concentration of 17.8 μM iron. The degradation of endosulfan by UV/Fe3+ or UV/Fe2+ was dramatically enhanced by adding peroxide (i.e., H2O2, S2O82- or HSO5-). Among the UV/peroxide/Fe processes, the highest degradation efficiency of 99.0% at UV fluence of 360 mJ/cm2 was observed by UV/HSO5-/Fe2+ with 2.45 μM [endosulfan]0, 17.8 μM [Fe2+]0, and 49.0 μM [HSO5-]0. The observed degradation rate constant of endosulfan was promoted either by increasing [Fe2+]0 and/or [peroxide]0 or by decreasing [endosulfan]0, while the initial degradation rate of endosulfan increased with increasing [Fe2+]0, [peroxide]0, or [endosulfan]0. At UV fluence of 6000 mJ/cm2, 45.0% mineralization as represented by the decrease in total organic carbon content was observed by UV/HSO5-/Fe2+ at 9.80 μM [endosulfan]0, 980 μM [HSO5-]0, and 17.8 μM [Fe2+]0. The major by-product of endosulfan was observed in all cases to be endosulfan ether which was further degraded with an extended reaction time. The results suggest that iron-mediated advanced oxidation processes (AOPs) have a high potential for the removal of endosulfan and its by-product from contaminated water.
AB - This study investigated iron-mediated oxidative processes for the photochemical degradation of endosulfan, a chlorinated insecticide and central nervous system disruptor. At UV fluence of 360 mJ/cm2, 52.4% and 32.0% removal of 2.45 μM initial endosulfan was observed by UV/Fe3+ and UV/Fe2+ processes, respectively, at an initial concentration of 17.8 μM iron. The degradation of endosulfan by UV/Fe3+ or UV/Fe2+ was dramatically enhanced by adding peroxide (i.e., H2O2, S2O82- or HSO5-). Among the UV/peroxide/Fe processes, the highest degradation efficiency of 99.0% at UV fluence of 360 mJ/cm2 was observed by UV/HSO5-/Fe2+ with 2.45 μM [endosulfan]0, 17.8 μM [Fe2+]0, and 49.0 μM [HSO5-]0. The observed degradation rate constant of endosulfan was promoted either by increasing [Fe2+]0 and/or [peroxide]0 or by decreasing [endosulfan]0, while the initial degradation rate of endosulfan increased with increasing [Fe2+]0, [peroxide]0, or [endosulfan]0. At UV fluence of 6000 mJ/cm2, 45.0% mineralization as represented by the decrease in total organic carbon content was observed by UV/HSO5-/Fe2+ at 9.80 μM [endosulfan]0, 980 μM [HSO5-]0, and 17.8 μM [Fe2+]0. The major by-product of endosulfan was observed in all cases to be endosulfan ether which was further degraded with an extended reaction time. The results suggest that iron-mediated advanced oxidation processes (AOPs) have a high potential for the removal of endosulfan and its by-product from contaminated water.
KW - Advanced oxidation processes (AOPs)
KW - Endosulfan
KW - Iron
KW - Peroxides
KW - UV-254 nm
KW - Water treatment
UR - https://www.scopus.com/pages/publications/84946893831
UR - https://www.scopus.com/pages/publications/84946893831#tab=citedBy
U2 - 10.1016/j.jphotochem.2015.03.014
DO - 10.1016/j.jphotochem.2015.03.014
M3 - Article
AN - SCOPUS:84946893831
SN - 1010-6030
VL - 306
SP - 80
EP - 86
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
ER -