过硫酸铵液相高级氧化法净化NO的实验研究

Removal of NO by ammonium persulfate advanced oxidation in aqueous solution

将过硫酸铵液相高级氧化法应用于烟气中NO的深度净化,以过硫酸铵-NO为实验体系,鼓泡反应器为气液反应装置,考察了净化液温度、Fe^2+-EDTA浓度和过硫酸铵浓度等对净化率的影响。结果表明,NO净化率随温度、Fe^2+-EDTA浓度和过硫酸铵浓度的增大而增大,随pH增大而减小。Fe^2+-EDTA为活化剂时,可使液相内Fe^2+质量浓度保持在0.003~0.004 mg/L,保证了对过硫酸铵长时间、高效活化。在最佳操作参数下,净化率达69.8%。通过添加自由基抑制剂探索了2种自由基对净化率的贡献率,硫酸根自由基·SO4^-的贡献率为46.4%,羟基自由基·OH的贡献率为30.8%,过硫酸铵液相高级氧化法净化NO主要是通过产生·SO4^-达到净化的目的。

Ammonium persulfate liquid phase advanced oxidation method is applied to deep removal of NO in flue gas.Ammonium persulfate-NO is used as an experimental system,and a bubbling reactor is used as a gas-liquid reaction device.Influences of purification solution temperature,the concentrations of Fe^2+-EDTA and ammonium persulfate on the removal rate are investigated.The results show that the removal rate of NO increases with increasing purification solution temperature,Fe^2+-EDTA concentration and ammonium persulfate concentration,and decreases with increasing pH value.The concentration of Fe^2+in the liquid phase can be maintained in the range of 0.003-0.004 mg·L^-1 when Fe^2+-EDTA is used as an activator,which ensures long-term and high-efficiency activation of ammonium persulfate.Under the optimum operation parameters,the removal rate can reach 81.3%.The contribution rates of two free radicals to the removal rate is explored through adding a free radical inhibitor into the solution,respectively.The contribution rates of sulfate free radical·SO4-and hydroxyl radical·OH are 46.4%and 30.8%,respectively.It is concluded that the removal of NO by ammonium persulfate liquid phase advanced oxidation method is mainly achieved by generating·SO4^-.