Mineralisation of 2,4-dichlorophenoxyacetic acid by acoustic or hydrodynamic cavitation in conjunction with the advanced Fenton process.
The mineralisation of 2,4-dichlorophenoxyacetic acid (2,4-D) in the presence of zero-valent iron and hydrogen peroxide (the advanced Fenton process--AFP) whilst being subjected to acoustic or hydrodynamic cavitation is reported. If the reaction is merely stirred then there is 57% removal of TOC whilst on irradiation the figure is 64% although the latter reaction is more rapid. Use of ultrasound alone results in only 11% TOC removal in 60 min of treatment time. Addition of iron powder marginally enhances the extent of degradation but an appreciable increase is observed in the presence of hydrogen peroxide which acts as a source for hydroxyl radicals by Fenton chemistry as well as by dissociation in the presence of ultrasound. The use of hydrodynamic cavitation in conjunction with the advanced Fenton process has also been found to be a useful tool for continuous remediation of water contaminated with 2,4-D. After 20 min of treatment the residual TOC is reduced to 30% and this probably represents the remaining highly recalcitrant small organic molecules.
School of Contemporary Sciences, University of Abertay Dundee, Bell Street, Dundee DD1 1HG Scotland, UK. Electronic address: d.bremner@abertay.ac.uk.
David H
DH
Bremner
Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via P. Giuria 9, 10125 Torino, Italy.
Stefano Di
SD
Carlo
School of Contemporary Sciences, University of Abertay Dundee, Bell Street, Dundee DD1 1HG Scotland, UK.
Anand G
AG
Chakinala
Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via P. Giuria 9, 10125 Torino, Italy.
Giancarlo
G
Cravotto
D015084:2,4-Dichlorophenoxyacetic Acid / Q000737:chemistry* / Q000528:radiation effects*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry; D014465:Ultrasonics
D016877:Oxidants; D015084:2,4-Dichlorophenoxyacetic Acid; D006861:Hydrogen Peroxide; D007501:Iron