氯离子活化过氧乙酸对罗丹明B的降解性能及机理研究

为解决传统H₂O₂(过氧化氢)体系对高盐特性染料废水去除效率低的问题，筛选合适的氧化剂迫在眉睫. PAA(过氧乙酸)因具备氧化还原电位较高、裂解所需键能较低、对pH适应范围更广等优点具有巨大的应用潜力. 因此，采用高浓度梯度Cl-活化PAA用于去除RhB(罗丹明B)，通过对比不同体系的降解效果、控制Cl-浓度和PAA投加量等反应条件，探究Cl-/PAA体系降解RhB的催化性能及反应机理. 结果表明:①Cl-/PAA体系对RhB的氧化能力远高于Cl-/H₂O₂体系，并且RhB降解过程符合拟一级反应动力学模型，提高氧化剂PAA的投加量和催化剂Cl-的浓度、降低初始RhB浓度均有利于目标污染物的去除. ②在初始RhB浓度为10 mg/L、PAA投加量为2.0 mmol/L、Cl-浓度为400 mmol/L后续处理条件下，10 min内RhB的降解率达到96.2%. ③pH对RhB的降解影响微弱, Fe3+促进了RhB的降解，K+对降解过程轻微抑制，NO₂-、CO₃2-、HCO₃-则表现出非常显著的抑制作用，脱色率分别降低了70.8%、83.8%和90.8%，而Mn2+、SO₄2-对RhB降解无显著影响. ④RhB在超纯水、自来水及反渗透水不同水源中的降解率无明显变化，具有良好的应用前景；结合自由基捕获试验及电子自旋共振证明，Cl-/PAA体系中产生的乙酰氧基、乙酰过氧基及单线态氧是在RhB降解中起主导作用的活性物质. 研究显示，Cl-活化PAA对去除罗丹明B具有较高的催化活性，通过模拟实际废水证明Cl-/PAA是一种可行的高级氧化技术. 

Degradation Performance and Mechanism of Rhodamine B by Chloride Activated Peracetic Acid

In order to solve the problem of low efficiency of conventional hydrogen peroxide systems in removing dye from high-salt wastewater, suitable oxidants are urgent need. Considering the advantages of peracetic acid (PAA) with higher redox potential, lower bond energy, and wider pH adaptation range, PAA is used for the removal of Rhodamine B (RhB) with a high concentration gradient of Cl- activation in this study. The catalytic performance and reaction mechanism of the Cl-/PAA system for RhB degradation is investigated by comparing the degradation effects of different systems and controlling the reaction conditions such as Cl- concentration and PAA dosage. The experimental results show that: (1) The oxidation capacity of the Cl-/PAA system for RhB is much higher than that of the Cl-/H₂O₂ system. The RhB degradation process follows the pseudo-first-order kinetics model, increasing the dosage of oxidant PAA and the concentration of catalyst Cl-, and decreasing the initial RhB concentration are beneficial to the removal of target pollutants. (2) Under the initial RhB concentration of 10 mg/L, PAA dosing of 2.0 mmol/L and Cl- concentration of 400 mmol/L reaction conditions, the degradation efficiency of RhB reached 96.2% within 10 min. (3) The effect of pH on the degradation of RhB is weak. Fe3+ promotes the degradation of RhB, K+ slightly inhibits the degradation process, while NO₂-, CO₃2- and HCO₃- show very significant inhibition. The decolorization efficiencies are reduced to 70.8%, 83.8% and 90.8%, respectively, while Mn2+ and SO₄2- have no significant effect on the degradation of RhB. (4) The degradation efficiency of RhB in different water sources such as ultrapure water, tap water, and reverse osmosis water does not change significantly, confirming the promising application of the Cl-/PAA system. The combination of chemical reagent capture experiments and electron spin resonance determine that acetoxy, acetyl peroxy, and singlet oxygen generated in the Cl-/PAA system are the reactive species that play a dominant role in the degradation of RhB. This study improves that Cl- activated peracetic acid has high catalytic activity for the removal of RhB and demonstrates that the Cl-/PAA system is a feasible advanced oxidation technology.