UV-Fenton法降解溶液中甲醛的影响因素与机理

在以300 W中压汞灯为光源的光化学反应器中,研究了UV-Fenton氧化法处理含甲醛有机废水时Fe2+浓度、H2O2浓度、pH值、温度等影响因素的作用机制及其适宜条件,得出不同条件下甲醛废水降解的动力学规律。试验结果表明:甲醛质量浓度为30 mg/L时,H2O2投加浓度为2 mmol/L,H2O2与Fe2+投加摩尔比n(H2O2)∶n(Fe2+)=5,温度为室温23℃,pH=3,此条件下反应30 min,甲醛的去除率可达91.89%。在此基础上,对UV-Fenton法降解甲醛反应产物的紫外光谱分析表明中间产物为甲酸,甲酸的进一步氧化降解是甲醛彻底矿化的限速步骤。

Influencing factors and mechanism for degradation of formaldehyde solution by UV-Fenton process

The influencing factors like Fe2+ concentration,H2O2 concentration,pH value and temperature on treating formaldehyde-contained wastewater by UV-Fenton process were studied in the photochemistry reactor with 300 W medium pressure mercury lamp.The kinetic rules of formaldehyde solution degradation in different conditions were educed.The result shows that when the mass concentration of formaldehyde is 30 mg/L,the concentration of H2O2 is 2 mmol/L,n(H2O2) ∶n(Fe2+) = 5,operating temperature is 23 ℃,pH=3,after 30 minutes,the removal rate of formaldehyde achieves 91.89%.The analysis of reaction products by UV spectrum confirms that the further oxidation and degradation of the intermediate product,formic acid,is the bottleneck of the complete oxidation of formaldehyde.