基于均相的Fenton试剂双频超声波一体化降解对氯苯酚的研究

Degradation of 4-chlorophenol solution by homogeneous Fenton reagent-dual-frequency ultrasound synergetic technology

研究了基于均相的Fenton试剂双低频超声波一体化系统催化氧化降解水中对氯苯酚(4-CP)的降解历程,从动力学角度分析其协同效应.实验结果表明:从不同反应时间测得的紫外光谱可以看到,苯环的特征峰逐渐消失,这表明4-CP的苯环逐渐被打开,直至彻底被降解;通过对中间产物的分析,初步推测了4-CP在此系统下的降解历程.4-CP在单独双频超声波处理(22 kHz和40 kHz US),Fenton试剂氧化和Fenton试剂双低频超声波一体化系统下的降解均符合表观一级动力学,均相Fenton试剂双低频超声波一体化系统降解4-CP具有协同效应,反应活化能为28.08kJ/mol,指前因子K0为3 025.40 L/(mol.s).

4-Chlorophenol solution was treated by homogeneous Fenton reagent-dual-frequency ultrasound synergetic technology and the degradation mechanism and kinetics of 4-chlorophenol were studied. Experimental results show that UV-Vis spectrometry taken at different time shows the breakage of benzene ring and till the complete mineralization. According to the analysis of observed intermediates, the degradation processes of 4-Cholorophenol include the pyrogenation and hydroxyl radical oxidation to organic acids. The 4-CP degradation mechanism is presumed. It is found that 4-chlorophenol degradation follows pseudo-first order kinetics reaction under dual-fequency ultrasound radiation or Fenton reagent oxidation process, while it significantly enhances in the US/US/Fenton system. This indicates that there exist synergetic effects in the US/US/Fenton process. The reaction activation energy is about 28.08 kJ/mol and the pre-exponential factors K0 is 3 025.40 L/（mol· s）.