Comparison of advanced oxidation processes and identification of monuron photodegradation products in aqueous solution.
The photodegradation of monuron (3-(4-chlorophenyl)-1,1-dimethylurea) in aqueous solutions under simulated solar irradiation has been conducted by different advanced oxidation processes (UV/H(2)O(2), UV/H(2)O(2)/Fe(2+), UV/H(2)O(2)/TiO(2), UV/TiO(2), dark H(2)O(2)/Fe(3+)). The degradation rates were always higher for the homogeneous catalysis in photo-Fenton reactions (UV/H(2)O(2)/Fe(2+)) compared to the heterogeneous photocatalytic systems (TiO(2)/UV and UV/H(2)O(2)/TiO(2)). Optimal concentrations of Fe(2+) and H(2)O(2) for the abatement of the herbicide in the photo-Fenton system were found to be 1 mM Fe(II) and 10 mM H(2)O(2). Several intermediary products were identified using large volume injection micro-liquid chromatography with UV detection (mu-LC-UV), mu-LC-MS and GC-MS techniques and a degradation mechanism has been proposed.
Bobu
Maria
M
Department of Inorganic Chemistry, Faculty of Industrial Chemistry, Technical University of Iasi, Mangeron, Romania. maria.bobu@kjemi.uio.no
Wilson
Steven
S
Greibrokk
Tyge
T
Lundanes
Elsa
E
Siminiceanu
Ilie
I
D002384:Catalysis; D006540:Herbicides / Q000737:chemistry / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008782:Methylurea Compounds / Q000737:chemistry* / Q000528:radiation effects*; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
D006540:Herbicides; D008782:Methylurea Compounds; D016877:Oxidants; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D006861:Hydrogen Peroxide; D014025:Titanium; D007501:Iron; C100088:monuron