石墨毡阴极电Fenton法降解水中苯甲酸的研究

Benzoic acid degradation by the electro-Fenton method using a graphite felt cathode

采用石墨毡阴极在上、钛钌铱网状阳极在下、以60°倾斜角平行放置的电解槽以及紫外光谱分析和荧光光谱分析方法,对电Fenton法氧化降解水溶液中苯甲酸的效果、条件及机理进行了研究。结果表明,通过斜放电极增加石墨毡阴极与氧气泡的接触机会,有利于H2O2的生成,通过适量添加Fe2+并保持水溶液适当的酸性,有利于H2 O2向.OH的原位顺利转化;电Fenton法氧化降解苯甲酸的较佳条件为:pH=3,Fe2+添加量25 mg/L,电解电流密度3 mA/cm2;在用电Fenton法彻底氧化降解苯甲酸的过程中,存在着苯甲酸转化生成对羟基苯甲酸和间羟基苯甲酸的中间步骤。

Benzoic acid degradation by the electro-Fenton method has been studied by fluorescence measurements and ultraviolet spectroscopy,in a novel electrolytic cell in which a graphite felt cathode was placed above a titanium-ruthenium/iridium anode,and the electrodes were tilted by 60° with respect to the electrolyzer base.This design favors electro-generation of H2O2 by extending the contact time between oxygen and the cathode,and hydroxyl radicals were generated in situ from H2O2 catalyzed by an appropriate amount of Fe2＋ in acid solution.Optimum electro-degradation of benzoic acid was achieved with a current density of 3 mA/cm2,an initial pH of 3,and a ferrous ion concentration of 25 mg/L.It was found that that p-hydroxybenzoic acid and m-hydroxybenzoic acid were generated as intermediate products in the degradation of benzoic acid.