中性条件下超声波／零价铁协同降解活性艳红X-3B

THE DEGRADATION OF REACTIVE RED X-3B BY ULTRASOUND SYNERGIZED WITH ZERO-VALENT IRON IN NEUTRAL MEDIUM

考察了中性条件下超声波降解、零价铁还原及超声波-零价铁联用对活性艳红X-3B模拟废水的降解效果,通过对比降解过程中UV-Vis光谱的变化,探讨了超声波-零价铁协同处理活性艳红X-3B的可行性．结果表明,在中性条件下超声波对活性艳红X-3B降解缓慢,经过25min辐射后,活性艳红X-3B的分解率不足7．5％;零价铁直接还原速率较慢,反应25min后,活性艳红X-3B的分解率仅为48．82％;“超声波／零价铁”对降解活性艳红X-3B有明显的协同效应,25min后分解率达99．42％(600W),反应符合准一级动力学过程．与零价铁直接还原相比,在200W,400W和600W超声波的协同作用下,X-3B降解的表观反应速率常数分别提高了2．12,2．76和4．00倍,半衰期相应缩短．另外,添加H2O2会抑制协同效应．

The degradation of X-3B by ultrasound, zero-valent iron and their combination was studied in neutral medium. The feasibility of ultrasound synergized with zero-valent iron was explored by analyzing the UV-Vis spectra of modeling wastewater. The results showed that the degradation rate of X-3B was very slow in neutral medium and only 7.5% of X-3B was removed after 25min irradiation. 48.82 % of X-3B was reduced by zero-valent iron after 25min reaction. However, the degradation rate of X-3B was improved remarkably by ultra- sound synergized with zero-valent iron and 99. 42 % of X-3B was removed after 25min ultrasound irradiation （600W）. The degradation of X-3B by synergistic system and zero-valent iron alone was followed with pseudo first order kinetics. Under 200W, 400Wand 600W ultrasound irradiation, the pseudo first order kinetics constant of synergistic system increased 2. 12, 2. 76 and 4. 00 times, respectively, compared with that of zero- valent iron alone. The synergistic effect was inhibited when adding H2O2.