超声、过硫酸钾协同去除水中诺氟沙星的效果

Norfloxacin Solution Degradation Under Ultrasound, Potassium Persulfate Collaborative System

过硫酸钾活化可产生强氧化性硫酸根自由基(SO-4·),采用超声/过硫酸钾体系氧化降解诺氟沙星,考察了过硫酸钾浓度、诺氟沙星初始浓度、溶液初始p H值及自由基淬灭剂甲醇、叔丁醇对降解效果的影响.结果表明,超声/过硫酸钾体系能够显著降解和矿化诺氟沙星,与单独过硫酸钾、超声相比,超声/过硫酸钾对诺氟沙星的去除率分别提高了3.2和8.9倍,降解过程符合一级反应动力学.诺氟沙星的去除率随过硫酸钾浓度的增加趋于平缓.p H对诺氟沙星的降解影响较大,这是因为随p H的升高,体系中的氧化性物种由SO-4·转化为以SO-4·/HO·为主.TOC去除和大肠杆菌抗菌实验表明,反应180 min,超声/过硫酸钾能够实现49.12%的诺氟沙星矿化,且对大肠杆菌的抑菌圈直径由45 mm减小到14 mm(滤纸直径),完全去除其抗菌性.结果表明超声/过硫酸钾能够有效用于诺氟沙星废水处理.

High oxidative sulfate radicals can be produced by potassium persulfate( K2S2O8). The integrated effect of ultrasonic and K2S2O8 on norfloxacin degradation was investigated. The experimental parameters such as K2S2O8 concentration,norfloxacin initial concentration,initial p H value,free radicals quenching agents such as methanol and tert-butyl on norfloxacin degradation were discussed. The results indicated that ultrasonic / K2S2O8 system had an obvious degradation and mineralization effect on norfloxacin.Norfloxacin removal efficiencies were 3. 2 and 8. 9 times in ultrasonic / K2S2O8 system than those in single K2S2O8 and ultrasonic oxidation system,respectively. And the reaction followed the first-order kinetics. Norfloxacin removal efficiency varied gently with K2S2O8 concentration. Solution initial p H had a significant effect on norfloxacin degradation,which was attributed to the different oxidizing species under different p H values. The radicals were sulfate radicals under acidic and neutral conditions,and was the combination of sulfate and hydroxyl radicals under alkaline conditions. TOC and agar diffusion test with E. coli showed that 49. 12%norfloxacin was mineralized and antibacterial activity was completely removed,with the diameter of E. coli inhibition zone decreased from 45 mm to 14 mm( filter paper diameter). The result implied that ultrasound / K2S2O8 showed promising results as a possible application for treatment of norfloxacin antibiotics wastewater.