对苯醌活化过硫酸盐降解罗丹明B的动力学特征及其影响因素

考察了对苯醌(HQ)活化过硫酸盐(PS)过程中降解罗丹明B(RhB)的动力学特征及其影响因素.结果表明:HQ含量、pH值以及温度对活化PS降解RhB的动力学过程和特征均产生不同程度的影响.在pH=4.6时,HQ能有效活化PS,显著促进其对罗明丹B的降解效能;随着体系中HQ含量的上升,RhB的降解程度得到提升,反应速率常数k的值与体系中HQ含量之间呈线性相关.在HQ的活化作用下,PS降解RhB反应的活化能由41.99kJ/mol降低至13.90kJ/mol,RhB降解程度和反应速率均得到提升.当pH=4.6,HQ=0.1mmol/L以及PS=1.0mmol/L时,HQ活化PS的过程中罗丹明B降解率可高达90%以上,反应速率增加了106%.染料RhB在充当表征活化PS效果试剂的同时,也积极参与了HQ活化PS过程,使得“HQ-RhB-PS”耦合体系的氧化降解能力得到显著提升.

The characteristics of degradation of rhodamine B by quinone-activated persulfate process

The current study mainly investigated the influences of concentration of HQ, pH, and temperature on the characteristics of rhodamine B degradation by HQ -activated persulfate process. The results showed the extent of rhodamine B degradation was enhanced significantly by persulfatein the presence of activator (HQ). The extent of rhodamine B degradation in acid reaction systems was higher than those in basic reaction system during HQ-activated persulfate process.And the extent of rhodamine B degradation also increased with the increasing contents of HQ. A linear relationship exists between reaction rate constants and HQ contents with correlation coefficients R² in a range from 0.9498 to 0.9951. Furthermore, in the presence of HQ, the activation energies decreased from 41.99kJ/mol to 13.90kJ/mol, and consequently, the reaction rate and efficiency of rhodamine B degradation were elevated high enough to 90 percent and the reaction rate constant increased by 106 percent. It was attributed to the semi-quinone racial generated by the HQ in reaction system, because semi-quinone racial could effectively activate the persulfate. Thus the efficiency of rhodamine B degradation was enhanced significantly in the interaction system of “HQ-RhB-persulfate”.