CoFe_(2)O_(4)的制备及活化过氧乙酸降解诺氟沙星

Preparation of CoFe_(2)O_(4) and degradation of norfloxacin by activated peracetic acid

利用溶胶凝胶结合自蔓延燃烧法,制备出具有良好磁性的CoFe_(2)O_(4)。通过正交实验,探究了硝酸盐与柠檬酸比例、pH值与煅烧温度对制备出的CoFe_(2)O_(4)活化过氧乙酸(PAA)降解诺氟沙星的影响,选出最佳的制备参数。在CoFe_(2)O_(4)最佳制备参数下考察了CoFe_(2)O_(4)投加量、PAA质量浓度、初始pH和水体中干扰物质(HCO_(3)^(-)、Cl^(-)、SO_(4)^(2-)和腐殖酸)对CoFe_(2)O_(4)活化PAA降解诺氟沙星的影响。在pH为7的环境下,CoFe_(2)O_(4)+PAA的氧化体系在35 min内对诺氟沙星的降解率达到70%,相比CoFe_(2)O_(4)和CoFe_(2)O_(4)+H_(2)O_(2)等体系展现出更高效的降解效率。自由基猝灭实验表明有机自由基(R—O·)是CoFe_(2)O_(4)+PAA体系降解诺氟沙星过程中占据主导作用的自由基。

CoFe_(2)O_(4)was successfully prepared by sol-gel combined with self-combustion method and showed good magnetic properties.The effects of nitrate salt/citric acid ratio,pH and calcination temperature on the degradation of norfloxacin by peracetic acid activated by CoFe_(2)O_(4)were investigated by orthogonal experiment,and then the best preparation parameters were selected.The effects of CoFe_(2)O_(4)dosage,peracetic acid(PAA)concentration,initial pH and interfering substances(HCO_(3)^(-)、Cl^(-)、SO_(4)^(2-) and humic acid)in water on the degradation of norfloxacin by CoFe_(2)O_(4)activated PAA were investigated under the optimum preparation parameters of CoFe_(2)O_(4).The degradation rate of norfloxacin by the oxidation system of CoFe_(2)O_(4)+PAA reached 70%within 35 min in the pH 7,which showed higher degradation efficiency than CoFe_(2)O_(4)and CoFe_(2)O_(4)+H_(2)O_(2).The experiment of radical quenching showed that organic radical(R—O)was the dominant radical in the degradation of norfloxacin by CoFe_(2)O_(4)+PAA systems.