Degradation of 4-chlorophenol mediated by Fe(III)-NTA in homogeneous and heterogeneous systems.
In this work, the comparison of 4-chlorophenol (4-CP) degradation by two different AOT processes has been performed: a) a homogeneous system with Fe(III)-NTA (1:1 complex), b) a TiO2/Fe(III)-NTA heterogeneous system. In both cases, NTA appears to play a positive role in the photochemical reaction. In the homogeneous system, the iron salt is the only absorbing species and is proved to be able to photoinduce 4-CP degradation ([4-CP] = 0.1-0.2 mM, [FeNTA] = 0.3-0.9 mM, pH 4, lambda = 365 nm). The progress of the reaction was positively affected by the FeNTA concentration, and the reaction kept going even after the total disappearance of FeNTA. However, 4-CP complete degradation requires the presence of oxygen, otherwise the reaction stops. In the heterogeneous system ([4-CP] = 2.0 mM, [FeNTA] = 1.0-2.0 mM, [TiO2] = 0.1 and 1.0 g L(-1), pH 3, lambda = 300-400 nm), an important effect of the complex on the degradation extent and on the initial reaction rate can be seen, which overcomes the effect of non-complexed Fe(III). This behaviour is more important at the highest TiO2 concentration.
Abida
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Laboratoire de Photochemie Moléculaire et Macromoléculaire, UMR 6505 CNRS-Université Blaise Pascal, 63177 Aubiere Cedex, France.
Emilio
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C
Quici
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Gettar
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R
Litter
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M
Mailhot
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G
Bolte
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M
D002733:Chlorophenols / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D009153:Mutagens / Q000737:chemistry*; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives* / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D010777:Photochemistry; D012388:Root Canal Irrigants / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
D002733:Chlorophenols; D005290:Ferric Compounds; D009153:Mutagens; D016877:Oxidants; D012388:Root Canal Irrigants; C009495:titanium dioxide; C029107:4-chlorophenol; D014025:Titanium; D009571:Nitrilotriacetic Acid; C020326:ferric nitrilotriacetate