内分泌干扰物4-叔丁基苯酚在水中的氯化动力学研究

Kinetics of Endocrine Disrupting Chemical 4-tert-butylphenol During Chlorination in Aqua

对典型内分泌干扰物4-叔丁基苯酚(4-TBP)在水中的氯化反应动力学进行了研究.结果发现,在不同HOCl初始浓度和pH条件下,4-TBP能够迅速被氯氧化,4-TBP的氯化反应符合二级反应动力学.表观速率常数kapp与pH值有关,在pH为5和9左右时,kapp分别达到最小值和最大值;对氯化反应中的每一个基元反应的反应速率常数进行了计算,HOCl与4-TBP的酸催化反应及ClO-与4-TBP反应的速率常数分别为4.99×106L2.(mol2.min)-1和1.96×104L.(mol.min)-1,而HOCl与4-TBP的反应及HOCl与4-TBP-的反应较慢,4-TBP-与ClO-不发生反应.水处理中氯消毒工艺对4-TBP的降解有一定的影响,在氯投加量为3 mg/L时,4-TBP的半衰期为12.1 min.

The kinetics of endocrine disruptor 4-tert-butylphenol by chlorination in aqua was studied. The results showed that 4-TBP was rapidly oxidized by chlorine with different initial concentrations of HOC1 and pH, and second-order reaction kinetics was observed between 4-TBP and chlorine. The apparent kinetic rate constants were influenced by pH values, and kapp reached its highest and lowest level at pH 5 and 9 respectively. The kinetic rate constant of every elementary reaction was calculated. The rate constants for the acid-catalyzed reaction and the reaction between ClO^- and 4-TBP were 4.99 × 10^6 L2· （mol^2 ·min）^-1 and 1.96×10^4 L· （mol·min）^-1 respectively. The reaction between HOC1 and 4-TBP or HOC1 and 4-TBP- was very slow, and ClO- did not react with 4-TBP^- . 4-TBP was influenced by chlorine disinfection during water treatment. The corresponding half-life time was 12.1 rain when chlorine concentration was 3 mg/L.