Homogeneous (Fe(III)) and heterogeneous (TiO2) photocatalytic systems for pollutant removal from the aquatic compartment: comparison and complementarity.
Kinetics of the oxidative photodegradation of monuron (3-(4-chlorophenyl)-1-1-dimethylurea) in both homogeneous solution of Fe(ClO4)3 and heterogeneous suspension of TiO2, were investigated and compared. In the homogeneous system (Fe(II)), the speciation of Fe(III) aquacomplexes was shown to play an essential role in the rate of photodegradation. For high concentrations of TiO2 (> 500 mg L(-1)), the photodegradation rate was similar to the reaction rate obtained with a freshly prepared solution of Fe(II) (3 x 10(-4) mol L(-1)). In the combined system (TiO2 + Fe(III)), a synergy effect accelerating the monuron photodegradation was observed. Actually, in the presence of Fe(III) (in concentration compatible with a safe environment), a similar reaction rate for monuron photodegradation was obtained with a TiO2 concentration lower by a factor of 20.
Mestánková
H
H
Laboratoire de Photochimie, UMR 6505 CNRS, Université Blaise Pascal, 63177 Aubière Cedex, France.
Mailhot
G
G
Krýsa
J
J
Jirkovský
J
J
Bolte
M
M
D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D004396:Coloring Agents; D014873:Water Pollutants; C009495:titanium dioxide; D014025:Titanium; D007501:Iron