Song Weihua, Cooper William J, Mezyk Stephen P, Greaves John, Peake Barrie M
Urban Water Research Center, Department of Civil and Environmental Engineering, University of California, Irvine 92697-2175, USA.
Environ Sci Technol. 2008 Feb 15;42(4):1256-61. doi: 10.1021/es702245n.
Many pharmaceutical compounds and metabolites are currently found in surface and ground waters which indicates their ineffective removal by conventional water treatment technologies. Advanced oxidation/reduction processes (AO/ RPs) are alternatives to traditional water treatment, which utilize free radical reactions to directly degrade chemical contaminants. This study reports the absolute rate constants for reaction of three beta-blockers (atenolol, metoprolol, and propranolol) with the two major AO/RP radicals; the hydroxyl radical (*OH) and hydrated electron ((e-)aq). The bimolecular reaction rate constants for *OH are (7.05 +/- 0.27) x 10(9), (8.39 +/- 0.06) x 10(9), and (1.07 +/- 0.02) x 10(10), and for (e-)aq they are (5.91 +/- 0.21) x 10(8), (1.73 +/- 0.03) x 10(8), and (1.26 +/- 0.02) x 10(10), respectively. Transient spectra were observed for the intermediate radicals produced by hydroxyl radical reactions. In addition, preliminary degradation mechanisms and major products were elucidated using 60Co gamma-irradiation and LC-MS. These data are required for both evaluating the potential use of AO/RPs for the destruction of these compounds and for studies of their fate and transport in surface waters where radical chemistry may be important in assessing their lifetime.
目前在地表水和地下水中发现了许多药物化合物和代谢物，这表明传统水处理技术对它们的去除效果不佳。高级氧化/还原工艺（AO/RPs）是传统水处理的替代方法，它利用自由基反应直接降解化学污染物。本研究报告了三种β受体阻滞剂（阿替洛尔、美托洛尔和普萘洛尔）与两种主要的AO/RP自由基；羟基自由基（*OH）和水合电子（(e-)aq）反应的绝对速率常数。*OH的双分子反应速率常数分别为(7.05±0.27)×10^9、(8.39±0.06)×10^9和(1.07±0.02)×10^10，(e-)aq的双分子反应速率常数分别为(5.91±0.21)×10^8、(1.73±0.03)×10^8和(1.26±0.02)×10^10。观察到了羟基自由基反应产生的中间自由基的瞬态光谱。此外，利用60Coγ辐照和LC-MS阐明了初步的降解机制和主要产物。这些数据对于评估AO/RPs用于破坏这些化合物的潜在用途以及研究它们在地表水中的归宿和迁移都是必需的，在地表水中自由基化学对于评估它们的寿命可能很重要。
