Toward a Better Understanding of Fe(III)–EDDS Photochemistry: Theoretical Stability Calculation and Experimental Investigation of 4-tert-Butylphenol Degradation

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• 作者：Yanlin Wu ; Marcello Brigante ; Wenbo Dong ; Pascal de Sainte-Claire ; Gilles Mailhot
• 刊名：Journal of Physical Chemistry A
• 出版年：2014
• 出版时间：January 16, 2014
• 年：2014
• 卷：118
• 期：2
• 页码：396-403
• 全文大小：376K
• ISSN：1520-5215

文摘

The present work describes in detail the chemical structure of the complex Fe(III)鈥揈DDS and the predominance of different species with respect to pH. These results were obtained with ab initio calculations. From the photoredox process, the formation of hydroxyl radical was confirmed, and HO^{鈥?/sup> is the main species responsible for the degradation of the organic compound present in aqueous solution. The degradation of 4-tert-butylphenol (4-t-BP), used as a model pollutant, was investigated in different conditions. For the first time, the second-order rate constant of the reaction between HO鈥?/sup> and 4-t-BP and the formation rate of HO鈥?/sup> (R_{HO鈥?/sub>f) from the photochemical process were evaluated. Through the degradation of 4-t-BP, the effect of Fe(III)鈥揈DDS concentration, oxygen, and pH was also investigated. The pH, which plays a role in the iron cycle and in the Fe(III)鈥揈DDS speciation, was noticed as an important parameter for the efficiency of 4-t-BP degradation. Such a result could be explained by taking into account the complex speciation and presence of a predominant form (FeL鈥?/sup>) up to pH 8. These results are very useful for the use and optimization of such iron complexes in water treatment processes.}}