非均相UV/Fenton体系氧化降解愈创木酚的研究

Oxidation of Guaiacol by Heterogeneous Photo-Fenton Process

以浸渍法制备的Fe3+/γ-Al2O3为催化剂,研究了非均相UV/Fenton体系对木素类模型物愈创木酚的处理效果,并与非均相Fenton体系作比较。实验结果表明,非均相UV/Fenton体系能够有效地降解结构稳定的木素类模型物愈创木酚。在室温、初始pH值为6.3、投加2倍理论量的H2O2和1g/L自制的催化剂(Fe3+与H2O2的摩尔比为1∶31.6)、反应60min,初始质量浓度为50mg/L的条件下,愈创木酚的去除率可达到100%。非均相UV/Fenton和非均相Fenton反应90min,愈创木酚的总有机碳去除率分别为94.3%和17.2%,由此可知,紫外光与Fenton试剂存在协同效应,使体系的氧化能力明显增强。愈创木酚的矿化速率慢于去除速率,说明愈创木酚并不是立刻被降解为CO2和H2O,而是先被降解为其他小分子中间产物,最终完全矿化。

The effect of the heterogeneous UV/Fenton system on degradation of model compound of lignin guaiacol was investigated using Fe-exchanged γ-Al2O3 as catalyst which was prepared by impregnation method,and compared with the effect of heterogeneous Fenton system. It is found that heterogeneous photo-Fenton process was effective for the degradation of guaiacol with stable structure. At the ambient temperature,the initial pH=6.3,two times of stoichiometric quantities of H2O2,1 g/L catalyst （the Fe^3＋ and H2O2 molar ratio was 1：31.6）,50 mg/L guaiacol solution,the removal of guaiacol reached as high as 100% in 60 min. TOC removal by using heterogeneous UV/Fenton and heterogeneous Fenton process achieved 94.3% and 17.2% in 90 min respectively,because UV-light and Fenton＇s reagent had synergetic effect enhancing the oxidative ability of the process. The TOC removal rate was slower than the guaiacol removal rate in the same time. This indicated that guaiacol was not immediately mineralized to CO2 and H2O,but to smaller molecular intermediates and finally could be completely mineralized.