超声-Fe2+-K2S2O8/NaHSO3体系降解罗丹明B

采用超声促进、Fe²⁺活化的K₂S₂O₈/NaHSO₃联合体系（US-Fe²⁺-K₂S₂O₈/NaHSO₃体系）降解罗丹明B（RhB）。考察了RhB模拟废水脱色效果的影响因素,并研究了不同处理方法的协同效应,推测了反应机理。实验结果表明：在反应温度25 ℃、初始pH 5.18、超声功率250 W、K₂S₂O₈溶液（4.91 mmol/L）加入量1.2 mL、NaHSO₃溶液（4.91 mmol/L）加入量1.2 mL、n（K₂S₂O₈）∶n（Fe²⁺）=10、反应时间7 min的条件下,RhB模拟废水（50 mL）的脱色率达到89.45%;超声与Fe²⁺-K₂S₂O₈/NaHSO₃体系对RhB的降解产生了协同效应,降解反应符合表观一级反应动力学,速率常数增强因子可达13.6。自由基猝灭实验结果表明,硫酸根自由基和羟基自由基是攻击RhB 分子的活性自由基,硫酸根自由基起主要作用。

Degradation of rhodamine B using ultrasound-Fe2+-K2S2O8/NaHSO3 system

Rhodamine B （RhB） was degraded by the ultrasound promoted and ferrous ion activated K₂S₂O₈/NaHSO₃ combination system （US-Fe²⁺-K₂S₂O₈/NaHSO₃ system）. The factors affecting decolorization of the simulated RhB wastewater were studied. The synergistic effect of different treatment methods was investigated and the reaction mechanism was speculated. The experimental results show thatUnder the conditions of reaction temperature 25 ℃,initial pH 5.18,ultrasonic power 250 W,K₂S₂O₈ solution （4.91 mmol/L） volume 1.2 mL,NaHSO₃ solution （4.91 mmol/L） volume 1.2 mL,n（K₂S₂O₈）∶n（Fe²⁺） = 10 and reaction time 7 min,the decolorization rate of the simulated RhB wastewater reaches 89.45%;The US-Fe²⁺-K₂S₂O₈/NaHSO₃ system has synergistic effect on RhB degradation,which is in conformity with the pseudo-first order kinetics and the kinetics enhancement factor of which can reach13.6. The results of free radical quenching experiments show that sulfate radicals and hydroxyl radicals are active radicals that attack RhB molecules,and sulfate radicals play a major role.