非均相光Fenton降解⁃吹脱处理NTO工业洗涤水的研究

Treatment of NTO Washing Water with Heterogeneous Photo⁃fenton Oxidation⁃blowing off

为处理工业上洗涤3-硝基-1,2,4-三唑-5-酮(NTO)粗品所产生的酸性洗涤水,研究提出非均相光Fenton降解NTO并联合吹脱的处理方法。首先以共沉淀-浸渍法制备催化剂Fe2+-Fe3O4@AC,而后以氧化体系(UV/Fe2+-Fe3O4@AC/H2O2)降解稀释洗涤水中的NTO(约4 g·L^(-1)),考察初始pH、双氧水投加量、催化剂浓度对降解效果的影响及催化剂的稳定性,筛选最佳降解条件。通过控制反应条件、猝灭自由基及EPR自由基捕捉测试推测可能的NTO降解机理。研究最佳条件下降解随后吹脱的过程中稀释洗涤水的化学需氧量(COD)及氨氮(NH3-N)的变化。结果表明。该体系可高效降解NTO,最佳处理条件为pH为2,nH2O2∶nNTO为5、催化剂浓度1 g·L^(-1),150 min后可去除99%的NTO。催化剂稳定性好,5次循环实验后NTO去除率仍可达到82%。吹脱降解后废水的最终COD去除率与NH3-N去除率均大于99%。反应由·OH与·O2-共同作用,其中•OH发挥主要作用。

In order to treat the acidic washing water in the industrial production,heterogeneous photo-fenton degradation-blowing off is proposed.Firstly,the magnetic catalyst Fe2+-Fe3O4@AC was prepared by coprecipitation-impregnation.Then,the degradation of NTO in the washing water(about 4 g·L^(-1))with system(UV/Fe2+-Fe3O4@AC/H2O2)was studied.pH,addition of H2O2 and catalyst concentration were screened to obtain the best conditions.Five repeated experiments were carried out to study the catalyst stability.The importance of conditions,free radical quenching experiment and the EPR spectrum results were studied to speculate on a possible degradation mechanism.In the process of degradation under optimal conditions and blowing off,the change of COD and NH3-N were recorded.The results show that this system can degrade NTO efficiently.When pH is 2,nH2O2∶nNTO is 5 and catalyst concentration is 1 g·L^(-1),99%of NTO can be removed in 150 min.The catalyst has good sta-bility and the NTO removal rate can still reach 82%after 5 cycles.The removal rate of COD and NH3-N are both 99%after deg-radation and blowing-off.·OH and·O2-make a contribution to degradation and·OH plays a major role.