UV/Fe^(3+)/H_2O_2体系降解邻苯二甲酸二甲酯

Degradation of Dimethylphthalate by UV/Fe^(3+)/H_2O_2 System

利用UV/Fe3+/H2O2体系降解水溶液中的邻苯二甲酸二甲酯(DMP)。导致DMP有效降解的.OH来自Fe(Ⅲ)-H2O络合物、H2O2的光致激发以及由此引发的Fenton反应过程。分析了酯浓度、pH值、H2O2浓度和Fe3+用量等条件对DMP降解的影响。结果表明,pH=3.0,[Fe(Ⅲ)]0=9.0×10-4～2.9×10-3 mol/L,[H2O2]0=8.9×10-4～2.0×10-3 mol/L,光照75min条件下,50mol/L DMP的光降解率可达99%以上。DMP浓度增大时,降解率下降。pH=3.0时,对反应进程以一级反应动力学模型进行拟合的结果表明,H2O2是影响反应速率的主要浓度因素,可通过加快Fe3+转化成Fe2+的速度,达到减少其用量,降低处理成本的目的。

The degradation of dimethyl phthalate （DMP） in aqueous solution was examined by UV/Fe^3＋/H2O2 technology. Hydroxyl radicals, · OH resulting in effective degradation of DMP were formed in via photo excitation of Fe（ III ） - H2O complex, H2O2 and Fenton process was initiated. Also the effects of various operating parameters,such as pH value, H2O2, Fe^3＋ and DMP concentration on degradation of DMP were analyzed. According to the experimental result,the optimum conditions were obtained at initial pH = 3.0, with original Fe3＋ and Hz Oz concentrations of 9.0 × 10^-4 - 2.9 × 10^-3 mol/L and 8.9 × 10^-4 -- 2.0 × 10^-3 mol/L, under irradiation time of 75 min, the photodegradation rate of 50 mol/L DMP could reach more than 99 %. When DMP concentration increased, the photodegradation effect decreased. Also, a kinetic model related to DMP removal was calculated and the result showed that H2O2 was the dominant factor influencing reaction rate. Therefore,the aim of reducing the dosage of H2 O2 and cutting down the processing cost could be achieved by accelerating the converting speed of ferric into ferrous.