电解耦合类芬顿催化降解对硝基酚反应动力学及产物特性

Kinetics and end products of catalytic decomposition of p-nitrophenol by electro-Fenton-like reaction

在无隔膜反应器中以石墨为阴阳极，投加Fe2O3／γ—Al2O3催化剂作填料构成电解耦合类芬顿反应体系（即催化填料床曝气电解体系），对pH=2．5的100mg／L对硝基酚模拟废水电解处理5h，较之其他电化学对照体系处理效果明显增加，底物浓度及COD去除率分别达到89．38％和47．26％；对硝基酚降解过程遵循准一级动力学，反应速率常数较之单纯电解提高了44．O％～67．4％；B／C由单纯电解体系的0．13左右提升至O．506。电解耦合类芬顿反应电解体系出水中苯醌等芳香类化合物累积量明显减少，有机物主要以小分子脂肪酸的形式存在。根据中间产物推测对硝基酚的降解机理。

p-Nitrophenol solution （100 mg/L） with pH = 2.5 is electrolyzed for 5 hours in an electro-Fenton-like reaction system （catalytic-aeration packed bed reactor）, which uses graphite as electrodes and using Fe2O3/γ-Al2O3 catalyst as filler, the treatment efficiency can be significantly enhanced comparing with other blank control experiments, the removal rate of p- nitrophenol and COD can be 89.38% and 47.26%, respectively. The degrading process of p-nitrophenol is a pseudo f＇n＇st-order reaction, and the reaction rate constantly increases by 44.0% - 67.4% compared with the pure electrolytic system. The B/C rate can be promoted to 0.506 from 0.13 of the pure electrolytic system. There is a decrease in concentration of benzoquinone and other aromatic compounds in the outflow of electro-Fenton-like reaction system, while some short chains of fatty acids are the major organics in the effluent. The degrading mechanism of nitrophenol is speculated to bases on intermediate products.