Université Paris-Est, Laboratoire Géomatériaux et Géologie de l'Ingénieur, 5 boulevard Descartes, Champs-sur-Marne, 77454 Marne-la-Vallée Cedex 2, France.
J Phys Chem A. 2009 Oct 15;113(41):10988-93. doi: 10.1021/jp9069674.
This study reports the kinetics of the degradation of several chlorophenols (CPs), such as monochlorophenols (2-chlorophenol and 4-chlorophenol), dichlorophenols (2,4-dichlorophenol and 2,6- dichlorophenol), trichlorophenols (2,3,5- trichlorophenol and 2,4,5-trichlorophenol), 2,3,5,6-tetrachlorophenol, and pentachlorophenol, by the electro-Fenton process using a carbon felt cathode and a Pt anode. The effect of number and the position of the chlorine atoms in the aromatic ring on the oxidative degradation rate was evaluated and discussed. The oxidation reaction of all the CPs with hydroxyl radicals evidenced a pseudo-first-order kinetics and the rate constant decreased with increasing the number of chlorine atoms. The absolute rate constant of second-order reaction kinetics between CPs and (*)OH was determined by the competition kinetics method in the range of (3.56-7.75) x 10(9) M(-1) s(-1) and follows the same sequence of the apparent rate constants. The mineralization of several CPs and of a mixture of all CPs under study was monitored by the total organic carbon (TOC) removal and the chlorine release during mineralization was followed by ion chromatography. Our results demonstrated that more chlorinated phenols are more difficult to mineralize; however for all the tested CPs, almost quantitative release of chloride ions was obtained after 6 h of treatment.
本研究报告了几种氯酚（CPs）（如单氯酚（2-氯酚和 4-氯酚）、二氯酚（2,4-二氯酚和 2,6-二氯酚）、三氯酚（2,3,5-三氯酚和 2,4,5-三氯酚）、2,3,5,6-四氯酚和五氯酚）在使用碳纤维毡阴极和铂阳极的电芬顿过程中的降解动力学。评估并讨论了芳环上氯原子的数量和位置对氧化降解速率的影响。所有 CP 与羟基自由基的氧化反应均表现出准一级动力学，且随着氯原子数量的增加，氧化降解速率常数降低。通过竞争动力学法在（3.56-7.75）x10(9) M(-1) s(-1)范围内确定了 CP 与（*）OH 之间的二级反应动力学的绝对速率常数，且遵循与表观速率常数相同的顺序。通过总有机碳（TOC）去除监测几种 CP 和研究中所有 CP 的混合物的矿化情况，并通过离子色谱法跟踪矿化过程中氯离子的释放。研究结果表明，氯化程度更高的酚类化合物更难矿化；然而，对于所有测试的 CP，在 6 小时的处理后，几乎可以定量释放氯离子。
