US-UV-Fenton降解硝基苯

采用超声波(US)、紫外光(UV)和Fenton联合降解硝基苯,初步探讨了其作用规律。研究结果表明, UV可以促进双氧水转化自由基的效率,而US同时具有强化传质作用和超声氧化作用,两者均能够强化Fenton氧化硝基苯的降解过程。正交实验结果表明,H2O2初始浓度是硝基苯降解和矿化的最显著影响因素,反应时间和超声功率是矿化的显著影响因素。最佳反应条件为:H2O2 500 mg/L、Fe2+10 mg/L、反应时间60 min、超声波功率100 W,此时,硝基苯完全降解,TOC去除率达到73.0%。Fenton、UV/Fenton和US/UV/Fenton降解硝基苯过程均符合伪一级反应动力学模式,反应速率常数分别为3.37×10-2、3.81×10-2和5.10×10-2min-1。

Nitrobenzene degradation by combination of ultrasound,ultraviolet and Fenton

The hybrid advanced oxidation process of ultrasound (US), ultraviolet (UV) and Fenton was investigated for nitrobenzene (NB) degradation by batch experiments and the optimal reaction conditions were explored. UV could help H2O2 decomposition to ·OH and US could enhance mass transfer and play the role of oxidation, which could enhance NB degradation. Experimental results showed that H2O2 concentration was the most obvious factor affecting NB degradation and TOC removal. Reaction time and US power were also the obvious factors affecting TOC removal. Under the conditions of 500 mg/L H2O2, 10 mg/L Fe2+, 60 min reaction time and 100 W US power, NB was completely decomposed and TOC removal achieved 73.0%. The pseudo-first-order rate constants of NB degradation in Fenton, UV/Fenton and US/UV/Fenton processes were fitted to be 3.37×10-2, 3.81×10-2 and 5.10×10-2min-1, respectively.