Fenton法氧化脱除烟气中NO的影响因素的实验研究

摘要

在自制反应器中,研究了烟气温度、Fenton试剂温度、初始pH值、NO初始浓度、烟气流量、n(Fe2+)(H2O2)和溶液中Cl等对Fenton法氧化脱除NO的影响.从单因素不同取值带来的NO氧化率的波动幅度来看,烟气流量对NO的氧化效率影响最为显著,试剂温度、NO初始浓度和n(Fe2+)(H2O2)的影响次之,而烟气温度和初始pH值影响较小.分别选取烟气温度为70 ℃,Fenton试剂温度为25℃,烟气流量为400 ～600 mL/min,NO初始浓度为982 mg/m3,初始pH值为3,以及n(Fe2+)(H2O2)为0.05:1时,对应的NO氧化效率较好.而溶液中Cl-的存在,则会降低NO的氧化效率.此外,以原位滴加方式获得的Fenton体系,有效提高了寿命极短的(·OH)自由基的产出率和利用率,从而提高了NO的氧化效率.%The effect of flue gas temperature (Tgas),Fenton reagent's temperature (Tliq),initial pH value,NO initial concentration(CNO0),gas flow and moral rate of Fe2 + to H2O2 on the oxidation efficiency of NO were investigated in a selfdesigned reactor.From the point of the fluctuation ranges of oxidation efficiency of NO which resulted from different value of single factors,the results showed that the gas flow had a significant impact on the oxidation efficiency of NO,followed by the effect of the reagent temperature,NO initial concentration and moral rate of Fe2 + to H2O2,while the flue gas temperature and initial pH value had little effect.The optimum removal conditions were obtained as Tgas of 70 ℃,Tliq of 25 ℃,gas flow of 400 ～600 mL/min,CNO0 of 982 mg/m3,initial pH of 3,moral rate of Fe2+ to H2O2 of 0.05:1.And the existence of Cl-in the system decreased the oxidation efficiency of NO.In addition,the in situ dripping addition of Fe2+ and H2O2 improved the production and utilization of free radical (·OH) effectively,which enhanced the oxidation efficiency of NO significantly.