亚铁催化声化学降解罗丹明B

Enhancement of degradation of rhodamine B in aqueous solution by ultrasound/Fe^(2+) process

比较了不同金属离子对罗丹明B的声化学降解作用,发现超声时加入Fe2+反应速率常数为单独超声波降解时的1.6倍,反应在前5 h内符合假一级动力学。研究了亚铁离子强化声化学对罗丹明B的降解作用,考察了Fe2+用量,溶液初始pH值,曝气,反应温度和超声功率等因素对脱色速率的影响。研究表明,酸性条件有利于染料的脱色;有曝气时的声化学脱色速率常数是单独超声时的6倍;声化学反应的活化能较低,反应在低温就可以进行;超声功率的改变对脱色速率的影响不大。UV-VIS扫描图谱显示,染料在225 nm和256 nm处的紫外吸收明显降低,初步探讨了罗丹明B的降解机理。

Sonochemical degradation of different ions on rhodamine B was compared. The results show that the addition of Fe^2＋ increased reaction rate constant by 1.6 times and the degradation of rhodamine B in less than 5 h proceeded with pseudo first-order rate, then the Fe^2＋ enhanced sonochemical degradation was applied to treat rhodamine B wastewater. The effects of pH, aeration, temperature, ultrasonic power and FeSO4 concentration on decoloration rate were studied. As a result the decolorization of rhodamine B proceeded faster in acidic medium. The sonochemical decolorization rate constant increased by 6 times after aerating air. The effect of temperature on rate constant was visible though sonochemical active energy was small. The effect of ultrasonic power on rate constant was imperceptible. UV-VIS spectra of rhodamine B show that the UV absorption at 225 nm and 256 nm dropped dramatically. The preliminary degradation mechanism of rhodamine B was inspected through UV-VIS spectra analysis.