水热法制备MnO_(2)活化过硫酸盐降解水中的四环素

Preparation of MnO_(2)Activated Persulfate by Hydrothermal Method for Degradation of Tetracycline in Water

基于过硫酸盐的高级氧化技术在抗生素污染治理方面重要的应用价值,分别以MnSO_(4),MnCl_(2)和Mn(NO_(3))_(2)为原料,采用水热法制备3种MnO_(2),并利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和X射线光电子能谱(XPS)对制备的MnO_(2)进行表征,对比分析3种MnO_(2)催化过氧单硫酸盐(peroxymonosulfate,PMS)去除四环素的效果,通过猝灭实验研究催化作用的机理.结果表明:以MnSO_(4)制备的MnO_(2)具有纳米棒结构,对PMS表现出最佳催化效果,60 min内对50 mg/L四环素去除率为56.8%;催化过程中存在Mn(Ⅳ)/Mn(Ⅲ)循环,SO_(4)^(-)·,·OH和^(1)O_(2)对去除四环素均有贡献;MnO_(2)/PMS体系的pH>7时对四环素具有较高的去除率,10 mmol/L NO_(3)^(-)和Cl^(-)对四环素降解效率基本无影响,10 mmol/L HCO_(3)^(-)可促进四环素降解;该方法对3种四环素类抗生素去除的大小顺序为金霉素>四环素>土霉素,可用于抗生素污染的治理.

Advanced oxidation technology based on persulfate had important potential value in treating antibiotic pollution.We used MnSO_(4),MnCl_(2)and Mn(NO_(3))_(2)as raw materials to prepare three kinds of MnO_(2)by hydrothermal method.The prepared MnO_(2)was characterized by an X-ray diffractometer(XRD),scanning electron microscope(SEM)and X-ray photoelectron spectroscopy(XPS).The effects of three kinds of MnO_(2)catalysts on the removal of tetracycline(TC)by peroxymonosulfate(PMS)were compared and analyzed,and the catalytic mechanism was studied by quenching experiments.The results show that the MnO_(2)prepared by MnSO_(4)has a nanorod structure and the best catalytic effect on PMS.The removal rate of 50 mg/L TC is 56.8%within 60 min.There is an Mn(Ⅳ)/Mn(Ⅲ)cycle in the catalytic process,and SO_(4)^(-)·,·OH,and^(1)O_(2)all contribute to the removal of TC.The MnO_(2)/PMS system has a high removal rate for tetracycline when pH>7,10 mmol/L NO_(3)^(-)and Cl^(-)have no affect on the degradation efficiency of TC,and 10 mmol/L HCO_(3)^(-)can promote the degradation of TC.The order of removal of three tetracycline antibiotics by this method is chlortetracycline>TC>oxytetracycline,which can be used for the treatment of antibiotic pollution.