对苯二酚强化多相类-Fenton过程降解活性艳红MX-5B的效能与机理

The efficiency and mechanisms of the enhancement of hydroquinone on the degradation of reactive red MX-5B by heterogeneous Fenton-like reaction

用碱沉淀法制备的硅羟基氧化铁(Si-FeOOH)作多相类-Fenton反应的催化剂,探讨了室温条件下投加还原剂对苯二酚(HQ)对其催化H2O2降解活性艳红MX-5B的影响,同时考察了pH、H2O2浓度、催化剂Si-FeOOH投量及活性艳红浓度对活性艳红MX-5B脱色率的影响,并从溶铁量方面初步探讨了Si-FeOOH/H2O2/HQ体系降解活性艳红MX-5B的机理.结果表明,对苯二酚强化以Si-FeOOH为催化剂的多相类-Fenton反应降解活性艳红的效果显著.在pH=3,活性艳红初始浓度为10mg·L-1,对苯二酚浓度为0.55mg·L-1,Si-FeOOH投量为100mg·L-1,H2O2浓度为51mg·L-1的反应条件下,活性艳红MX-5B的脱色率达94.69%.研究还发现,活性艳红脱色率与反应体系里的铁离子浓度关系密切,表明多相类-Fenton反应中除了催化剂表面吸附催化作用外,也可能存在类似均相类-Fenton的溶液催化作用.

In this study a Si-FeOOH heterogeneous catalyst for the Fenton-like reaction was prepared by sodium hydroxide precipitation.At room temperature,the influence of hydroquinone on the degradation of reactive red MX-5B by Fenton-like was investigated.This paper also studied the influencing factors of Fenton-like reaction on the decolorizing rate of reactive red MX-5B,such as pH,the dosages of H2O2,Si-FeOOH and reactive red MX-5B.The mechanisms of the degradation of reactive red MX-5B by Si-FeOOH/H2O2/hydroquinone system were also discussed.Experimental results showed that the effect of the degradation of reactive red by Si-FeOOH heterogeneous Fenton-like reaction under the addition of hydroquinone was remarkable.The optimal conditions were the initial concentration of reactive red MX-5B 10 mg · L-1,Hydroquinone dosage 0.55 mg · L-1,catalyst dosage100 mg · L-1,and H2O2 dosage 51mg · L-1 at pH of 3.Under these conditions,the removal of reactive red MX-5B could reach 94.69%.In addition,the decolorizing rate of the reactive red MX-5B was correlated with the iron ions concentration in the reaction system.This result indicated that in the heterogeneous Fenton-like reaction,apart from the surface adsorbed catalysis,there may exist a homogeneous catalysis effect similar to homogeneous Fenton-like reaction in the solution.