针铁矿非均相Fenton法降解抗生素的研究

Heterogeneous Fenton Degradation Characteristics and Kinetics of Tetracycline in Aqueous Solution Catalysed by Goethite

采用合成的针铁矿为催化剂与H2O2构成非均相Fenton试剂,开展对盐酸四环素(TC)的氧化分解特征及其动力学研究.考察pH、H2O2浓度、催化剂投加量、TC初始浓度、温度对TC氧化分解过程的影响.结果表明,在优化条件下,针铁矿240 min后对TC的Fenton氧化分解率达到97.2%,主要通过·OH作用,因为加入叔丁醇自由基捕获剂后,TC的氧化分解率明显降低.此外,针铁矿表面催化氧化分解TC是符合准一级动力学反应(R2>0.97),其表观活化能为E a=31.86 kJ/mol.结果表明该反应比较容易进行,温度升高有助于提高反应速率.

The oxidative decomposition character and its degradation kinetic model of Tetracycline （TC） were investigated using goethite/H2O2 as the heterogeneous Fenton reagent, with emphasis on the evaluation of the several Fenton-like oxidation system parameters, including initial solution pH, concentrations of hydrogen peroxide （ H2O2 ） and α-FeOOH, initial concentration of TC, and reaction temperature. The results showed that a 97.2% decomposition efficiency for TC was obtained within 240 min under optimum conditions. Moreover, the addition of tertiary butyl alcohol （used as the . OH quencher） to the reaction system can cause obviously the decrease of TC decomposition rate, it suggested that the TC decomposition was dominated by . OH. In addition, goethite surfaces catalysed a heterogeneous Fenton-like reaction responsible for the TC decomposition following pseudo-first order kinetics （ R2 〉 0. 97 ）, and their apparent activation energy （ Ea ） measured was relatively low （ 31.86 kJ . mol ^- 1 ）, which implied that the ease of the Fenton decomposition reaction occurred generally and thus it is convenient for the actual application.