Degradation and by-product formation of diazinon in water during UV and UV/H"2O"2 treatment [An article from: Journal of Hazardous Materials]
Book Details
Author(s)H. Shemer, K.G. Linden
PublisherElsevier
ISBN / ASINB000PAA6S6
ISBN-13978B000PAA6S6
MarketplaceFrance 🇫🇷
Description
This digital document is a journal article from Journal of Hazardous Materials, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
Kinetics and degradation products resulting from the application of UV and UV/H"2O"2 to the US EPA Contaminant Candidate List pesticide diazinon were studied. Batch experiments were conducted with both monochromatic (low pressure [LP] UV 253.7nm) and polychromatic (medium pressure [MP] UV 200-300nm) UV sources alone or in the presence of up to 50mgl^-^1 H"2O"2, in a quasi-collimated beam apparatus. Degradation of diazinon by both UV and UV/H"2O"2 exhibited pseudo first order reaction kinetics, and quantum yield of 8.6x10^-^2 and 5.8x10^-^2molE^-^1 for LP and MP lamps respectively. Photolysis studies under MP UV lamp showed 2-isopropyl-6-methyl-pyrimidin-4-ol (IMP) to be the main degradation product of diazinon at aqueous solution pH values of 4, 7 and 10. Trace levels up to 1.8x10^-^3@mM of diazinon oxygen analogue diethyl 2-isopropyl-6-methylpyrimidin-4-yl phosphate (diazoxon) were detected only during the UV/H"2O"2 reaction. Decay of both products was observed, as the UV/H"2O"2 reaction prolonged, yet no mineralization was achieved over the UV fluence levels examined. Photolysis kinetics, quantum yield and UV/H"2O"2 degradation of the reaction product IMP was determined using MP UV lamp at pH values of 4, 7 and 10.
Description:
Kinetics and degradation products resulting from the application of UV and UV/H"2O"2 to the US EPA Contaminant Candidate List pesticide diazinon were studied. Batch experiments were conducted with both monochromatic (low pressure [LP] UV 253.7nm) and polychromatic (medium pressure [MP] UV 200-300nm) UV sources alone or in the presence of up to 50mgl^-^1 H"2O"2, in a quasi-collimated beam apparatus. Degradation of diazinon by both UV and UV/H"2O"2 exhibited pseudo first order reaction kinetics, and quantum yield of 8.6x10^-^2 and 5.8x10^-^2molE^-^1 for LP and MP lamps respectively. Photolysis studies under MP UV lamp showed 2-isopropyl-6-methyl-pyrimidin-4-ol (IMP) to be the main degradation product of diazinon at aqueous solution pH values of 4, 7 and 10. Trace levels up to 1.8x10^-^3@mM of diazinon oxygen analogue diethyl 2-isopropyl-6-methylpyrimidin-4-yl phosphate (diazoxon) were detected only during the UV/H"2O"2 reaction. Decay of both products was observed, as the UV/H"2O"2 reaction prolonged, yet no mineralization was achieved over the UV fluence levels examined. Photolysis kinetics, quantum yield and UV/H"2O"2 degradation of the reaction product IMP was determined using MP UV lamp at pH values of 4, 7 and 10.
