Deborde Marie, Rabouan Sylvie, Gallard Hervé, Legube Bernard
Laboratoire de Chimie de l'Eau et de l'Environnement, UMR CNRS 6008, Ecole Supérieure d'Ingénieurs de Poitiers-40, 86022 Poitiers Cedex, France.
Environ Sci Technol. 2004 Nov 1;38(21):5577-83. doi: 10.1021/es040006e.
The aqueous chlorination kinetics of six endocrine disruptors (EDs: 4-n-nonylphenol, beta-estradiol, estrone, estriol, 17alpha-ethinylestradiol, progesterone) were studied in the 3.50-12.00 pH range, at 20+/-2 degrees C, in the presence of an excess of total chlorine. Under these conditions, all molecules with a phenolic group in their structure were rapidly oxidized by chlorine, whereas progesterone remained unchanged. In the first step, apparent kinetic rate constants were determined at various pH levels. Then each elementary reaction kinetic rate constant, i.e., the reaction of hypochlorous acid (HOCl) with ionized EDs and neutral EDs and an acid-catalyzed reaction of HOCl with neutral EDs, was calculated in the second step. The results showed that chlorination exhibits a second-order reaction rate. The rate constants for the acid-catalyzed reaction ranged from 3.02 x 10(4) M(-1) s(-1) (for 4-n-nonylphenol) to 1.82-2.62 x 10(5) M(-1) s(-1) (for hormones). The rate constants of HOCI reactions with ionized EDs were found to be equal to 7.5 x 10(4) M(-1) s(-1) (for 4-n-nonylphenol) and between 3.52 and 4.15 x 10(5) M(-1) s(-1) (for hormones), while the rate contants of HOCI with neutral EDs were much lower, i.e., between 1.31 M(-1) s(-1) (for 4-n-nonylphenol) and 3.74-4.82 M(-1) s(-1) (for hormones). At pH 7, the apparent-second-order rate constants were calculated to range from 12.6 to 131.1 M(-1) s(-1). For a total chlorine concentration of 1 mg/L, the corresponding half-life times at pH 7 were about 65 min for 4-n-nonylphenol and 6-8 min for hormones.
在20±2℃、pH值为3.50 - 12.00的范围内，在总氯过量的条件下，研究了六种内分泌干扰物（EDs：4 - 正壬基酚、β - 雌二醇、雌酮、雌三醇、17α - 乙炔雌二醇、孕酮）的水相氯化动力学。在这些条件下，结构中含有酚羟基的所有分子都能被氯迅速氧化，而孕酮则保持不变。第一步，在不同pH值水平下测定表观动力学速率常数。第二步，计算每个基元反应动力学速率常数，即次氯酸（HOCl）与离子化EDs和中性EDs的反应以及HOCl与中性EDs的酸催化反应。结果表明，氯化反应表现出二级反应速率。酸催化反应的速率常数范围为3.02×10⁴ M⁻¹ s⁻¹（对于4 - 正壬基酚）至1.82 - 2.62×10⁵ M⁻¹ s⁻¹（对于激素）。发现HOCl与离子化EDs反应的速率常数等于7.5×10⁴ M⁻¹ s⁻¹（对于4 - 正壬基酚），在3.52至4.15×10⁵ M⁻¹ s⁻¹之间（对于激素），而HOCl与中性EDs的速率常数要低得多，即1.31 M⁻¹ s⁻¹（对于4 - 正壬基酚）至3.74 - 4.82 M⁻¹ s⁻¹（对于激素）。在pH值为7时，表观二级速率常数经计算范围为12.6至131.1 M⁻¹ s⁻¹。对于总氯浓度为1 mg/L的情况，在pH值为7时，4 - 正壬基酚的相应半衰期约为65分钟，激素的半衰期为6 - 8分钟。
