非均相类Fenton法降解硝基苯化工废水的效能及其机制

Performance of heterogeneous Fenton-like system for degradation of nitrobenzene-containing wastewater

以实验室制备的3A-Fe型分子筛为催化剂，并利用扫描电镜、能谱分析和XRD技术对催化剂进行了表征。在3A-Fe型分子筛与H2O2构建的非均相类Fenton催化体系内对硝基苯的降解效能和机制进行了研究，讨论了体系pH值、H2O2的投加量、催化剂投加量、硝基苯废水浓度对硝基苯降解率和反应速率的影响，并初步揭示了硝基苯的降解机理。结果表明：3A-Fe分子筛作为催化剂的类Fenton反应，在pH值2～10之间都具有较好的处理效果；类Fenton体系氧化降解反应过程是一种非均相的界面微观反应；3A-Fe类Fenton催化剂性能优越，对硝基苯废水中硝基苯的去除率为94．1％，CODc-和TOC的去除率分别为78．6％和60．5％。

A heterogeneous Fenton-like catalytic system, consisted of 3A-Fe zeolite catalyst that was prepared in the laboratory and characterized by SEM, EDS and XRD, and H2O2 was used for degradation of nitrobenzene-containing wastewater. The effects of pH, H2O2 and nitrobenzene concentration, and catalyst dose on degradation of nitrobenzene were studied. An attempt to reveal the degradation mechanism was also done. The results showed that nitrobenzene had been significantly degraded in this Fenton-like system provided that pH value of wastewater was in the range of 2 to 10. No dissolved Fe（ Ⅱ/Ⅲ） was detected for the Fenton-like system, indicating that nitrobenzene was directly degraded on surface of 3A-Fe zeolite catalyst rather than by the aqueous Fenton system. The 3A-Fe zeolite catalyst exhibited good stability in repeat use and the degradation rate of nitrobenzene could reach 94.1%, and the removal rate of CODcr and TOC, under the optimal conditions, were 78.6% and 60.5% respectively.