US/Fenton试剂法在水体系中降解对硝基苯酚的研究

Degradation of p-Nitrophenol in Water by Ultrasound/Fenton Reagent Method

将超声波(US)/Fenton试剂法有机地结合起来,用于对硝基苯酚(p-NP)的降解实验,实验中发现US/Fenton试剂法降解p-NP具有明显的协同效应,结果优于Fenton试剂法与US法的简单加合。全面考察了初始pH值、H2O2浓度和Fe2+浓度等因素对US/Fenton试剂法降解p-NP过程的影响。结果表明,在实验范围内,溶液的初始pH值越小,分子态的p-NP比例越大,越易于进行反应;同时H2O2的利用率越高,US/Fenton试剂法对p-NP的降解效果越好。H2O2和Fe2+浓度越高,·OH自由基的数量越多,·OH自由基有利于p-NP的降解,因此US/Fenton试剂法对p-NP的降解效果越好。

The application of ultrasound (US)/Fenton reagent method to the degradation of p-nitrophenol (p-NP) in water was studied. It is found that the degradation of p-nitrophenol by US/Fenton reagent method had an obvious synergistic effect. The result is better than the simple summation of Fenton reagent method and US method. The influences of initial pH value in solution, concentration of H2O2 and Fe2+ on the experimental results were studied in detail. Since the pH value will effect the p-NP existing state (in ionic state or in molecular state), with lower pH value, the p-NP will exist in a higher proportion of molecular state which is easier to be degraded by the ultrasonic cavitation. Moreover, under lower pH, the H2O2 becomes more effective. Therefore the experimental results show that the lower initial pH value will have better p-NP degradation. In addition, since the free radical &middotOH does favour the p-NP degradation, increasing the H2O2 and Fe2+ concentration will increase the number of free radical &middotOH, so at the same time it will make the p-NP degradation more effective.