Photocatalytic degradation of triazophos in aqueous titanium dioxide suspension: identification of intermediates and degradation pathways.
The photocatalytic degradation of triazophos in aqueous TiO2 suspension has been studied in a photoreactor operating with simulated solar radiation. The decrease in triazophos concentration followed first-order kinetics with a half-life of 4.76+/-0.42 h at a TiO2 suspension concentration of 10 mg/L. Seventeen degradation products were identified using HPLC-UV, HPLC/MS/MS, GC/MS/MS and IC, and by comparing retention times and spectra with commercially available authentic standards. On the basis of the observed transformation products, two routes were proposed, one based on the initial oxidative cleavage of PS bond to PO bond, and the other on initial cleavage of the ester P-O bonds. Photocatalysis holds promise for the solar treatment of pesticide-contaminated waters.
Aungpradit
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Postgraduate Education and Research Program in Analytical Chemistry, Department of Chemistry, PO Box 1011 Kasetsart, Kasetsart University, Bangkok 10903, Thailand.
Sutthivaiyakit
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P
Martens
D
D
Sutthivaiyakit
S
S
Kettrup
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AA
D002384:Catalysis; D007306:Insecticides / Q000737:chemistry / Q000528:radiation effects; D063086:Organothiophosphates / Q000737:chemistry* / Q000528:radiation effects*; D010777:Photochemistry; D013472:Sunlight; D014025:Titanium / Q000737:chemistry; D014230:Triazoles / Q000737:chemistry* / Q000528:radiation effects*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects*; D018508:Water Purification / Q000379:methods
D007306:Insecticides; D063086:Organothiophosphates; D014230:Triazoles; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; C012584:triazophos; D014025:Titanium