Fenton试剂强化双低频超声降解对氯苯酚的研究

Degradation of 4-chlorophenol (4-CP) by Fenton reagent improving dual-low frequency ultrasound technology

研究了Fenton试剂强化双低频超声波氧化对氯苯酚(4-CP)的降解效果、降解机理和动力学.探讨了影响4-CP降解的各种因素,最佳实验条件为22kHz超声波声强为15W/cm2,40kHz超声波输出电功率50W不变,25℃,初始pH为3～5,H2O2∶Fe2+(摩尔比)=20∶1,H2O2为(0.3～0.5)×10-3,富氧作为饱和气体.双频超声波处理4-CP降解速率比22和40kHz单独超声波处理提高了1.4倍;Fenton试剂强化双频超声波催化技术比单独双频超声波处理4-CP降解速率提高了1.3倍,并且降解过程符合一级反应动力学.双频超声波处理和Fenton试剂强化双频超声波氧化技术都具有明显的协同效应.

The 4-Chlorophenol solution was treated by Fenton reagent improving dual-low frequency ultrasound technology, and the major affecting factors such as sound intensity, initial pH, initial concentration, medium temperature and the sorts of saturating gas were studied. Experimental results show that the ultrasonic intensity and initial pH alter noticeably the reaction rates, under the preferable operating conditions as low pH, 20-40°C, 22 kHz ultrasound intensity of around 15 W&middotcm-2, constant 40 kHz ultrasound intensity, H2O2:Fe2+ (molar ratio) of about 20:l, the addition amount of H2O2 of about (0.3-0.5)×10-3 and use of abundant oxygen as saturating gas. The addition of Fenton reagent can increase the 4-CP removal rate, which obeys first-order kinetic law. After treatment, the enhancement of the 4-CP removal rate is around 130%. Therefore, the synergetic effect of Fenton reagent improving dual-low frequency ultrasound technology is obvious.