BiFeO_(3)/H_(2)O_(2)类芬顿体系降解废水中的四环素

Degradation of tetracycline in wastewater by BiFeO_(3)/H_(2)O_(2)Fenton-like system

采用炭吸附共沉淀法制备BiFeO_(3),构建BiFeO_(3)/H_(2)O_(2)类芬顿体系降解废水中的四环素,通过设置单因素条件考察了初始pH值、催化剂BiFeO_(3)的投加量、H_(2)O_(2)浓度对废水中四环素降解的影响。使用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)和全自动比表面及孔隙度分析仪(BET)等分析方法对样品进行表征。实验结果表明:四环素降解的最佳反应条件为初始pH值为4、BiFeO_(3)投加量为1.0 g/L、H_(2)O_(2)浓度为20 mmol/L,在此条件下,四环素的降解率为95.18%。BiFeO_(3)经过4次重复使用,类芬顿体系对废水中四环素的降解率没有显著变化,表示其稳定性好,可重复使用。自由基捕获实验表明,该体系中四环素降解作用最重要的活性物种是羟基自由基(·OH)和超氧自由基(·O_(2)^(-)),并提出了BiFeO_(3)活化H_(2)O_(2)降解四环素的机理。本研究为基于H_(2)O_(2)的高级氧化技术在污废水处理领域的应用提供参考。

BiFeO_(3)was prepared by carbon adsorption co-precipitation method,and then BiFeO_(3)/H_(2)O_(2)Fenton-like system was constructed to degrade tetracycline in wastewater.The effects of initial pH value,catalyst BiFeO_(3)dosing and H_(2)O_(2)concentration on the degradation of tetracycline in wastewater were investigated by setting single-factor conditions.The samples were characterized using X-ray diffraction(XRD),field emission scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),and fully automated surface area and porosity analyzer(BET)etc.The experimental results showed that the optimal reaction conditions for the degradation of tetracycline were the initial pH value of 4,BiFeO_(3)injection amount of 1.0 g/L and H_(2)O_(2)concentration of 20 mmol/L,under which the degradation rate of tetracycline was 95.18%.The degradation rate of tetracycline in wastewater by the Fenton-like system did not change significantly after four reapplications of BiFeO_(3),indicating that it is stable and reusable.The radical capture experiments showed that the most important active species for the degradation of tetracycline in this system are hydroxyl radicals(·OH)and super oxide radicals(·O_(2)^(-)).Based on the findings,we proposed a mechanism for the degradation of tetracycline by BiFeO_(3)activated H_(2)O_(2).This study provides a reference for the application of advanced oxidation technology on H_(2)O_(2)in the field of wastewater treatment.