亚铁催化声化学降解罗丹明B

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.

Enhancement of degradation of rhodamine B in aqueous solution by ultrasound/Fe2+ process

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 FeSO_4 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.