Institut National de la Recherche Scientifique (INRS-Eau Terre et Environnement), Université du Québec, 490 rue de la Couronne, Québec, Qc G1K 9A9, Canada; Laboratoire de Chimie Moléculaire et Environnement, Université de Savoie, 73376 Le Bourget du Lac, France.
Ultrason Sonochem. 2014 Jan;21(1):69-75. doi: 10.1016/j.ultsonch.2013.08.003. Epub 2013 Aug 13.
A sonophotochemical oxidation process has been used for the treatment of an aqueous solution of phenol. The aim of this work is to evaluate the effect of nitrate ions on hydroxyl radical production and on phenol oxidation. It has been demonstrated that ultrasound can produce NOx (nitrate and nitrite), with a production rate of 2.2 μM min(-1). The photolysis of nitrate can significantly improve the hydroxyl radical production. The apparent rate constant for hydroxyl radical production increased from 0.0015 min(-1) to 0.0073 min(-1) while increasing initial nitrate concentration from 0 to 0.5mM. The concentration of hydroxyl radical was directly proportional to the initial nitrate concentration. Using US/UV process, the apparent reaction rate constant of phenol degradation in the presence of nitrate reached 0.020 min(-1), which was relatively lower than the value obtained (0.027 min(-1)) in the absence of nitrate. It appeared that, nitrate ions can inhibit the sonochemical degradation of organic compounds such as phenol.
声光氧化工艺已被用于处理苯酚水溶液。本工作旨在评估硝酸根离子对羟基自由基生成和苯酚氧化的影响。结果表明，超声可产生 NOx（硝酸盐和亚硝酸盐），生成速率为 2.2 μM min(-1)。硝酸根的光解可显著提高羟基自由基的生成。当初始硝酸根浓度从 0 增加到 0.5mM 时，羟基自由基生成的表观速率常数从 0.0015 min(-1)增加到 0.0073 min(-1)。羟基自由基的浓度与初始硝酸根浓度成正比。在有硝酸根存在的情况下，采用 US/UV 工艺，苯酚降解的表观反应速率常数达到 0.020 min(-1)，这比在没有硝酸根存在时（0.027 min(-1)）获得的值相对较低。似乎硝酸根离子可以抑制有机化合物（如苯酚）的声化学降解。
