Abida O, Emilio C, Quici N, Gettar R, Litter M, Mailhot G, Bolte M
Laboratoire de Photochemie Moléculaire et Macromoléculaire, UMR 6505 CNRS-Université Blaise Pascal, 63177 Aubiere Cedex, France.
Water Sci Technol. 2004;49(4):123-8.
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.
在本研究中，对两种不同的高级氧化技术（AOT）降解4-氯苯酚（4-CP）的过程进行了比较：a）Fe(III)-NTA（1:1络合物）的均相体系，b）TiO2/Fe(III)-NTA非均相体系。在这两种情况下，NTA在光化学反应中似乎都起到了积极作用。在均相体系中，铁盐是唯一的吸光物种，并且已证明能够光诱导4-CP降解（[4-CP]=0.1 - 0.2 mM，[FeNTA]=0.3 - 0.9 mM，pH 4，λ = 365 nm）。反应进程受到FeNTA浓度的积极影响，即使FeNTA完全消失后反应仍在继续。然而，4-CP的完全降解需要氧气的存在，否则反应会停止。在非均相体系中（[4-CP]=2.0 mM，[FeNTA]=1.0 - 2.0 mM，[TiO2]=0.1和1.0 g L(-1)，pH 3，λ = 300 - 400 nm），可以看到该络合物对降解程度和初始反应速率有重要影响，这克服了未络合的Fe(III)的影响。在最高TiO2浓度下，这种行为更为显著。
