光电Fenton耦合转盘技术处理四环素废水  

Photo-electro-Fenton degradation of tetracycline based on rotating disk electrode

作　　者：张岩[1] 高明明[1] 王新华[1] 王曙光[1] 刘瑞婷[1] 

机构地区：[1]山东大学环境科学与工程学院,济南250100

出　　处：《环境化学》2016年第5期893-900,共8页Environmental Chemistry

基　　金：国家自然科学基金(21007033)资助~~

摘　　要：本实验中,我们开发了一种耦合紫外光催化和转盘技术的电Fenton反应器用于降解含有四环素的有机废水.在该反应器中,O_2首先在旋转的石墨阴极表面发生还原反应生成H_2O_2,随后H_2O_2被催化分解成活性自由基来降解矿化有机物.实验中了考察了pH,阴极电压,转速等实验条件对系统生成H_2O_2能力的影响.结果表明,在pH=3,阴极电压-0.8 V vs.SCE,转速为400 r·min^(-1)条件下,经过75 min反应H_2O_2的积累浓度有最大值(51.5 mg·L^(-1)).实验证明该系统对四环素有较好的降解和矿化效果.以1.0 mmol·L^(-1)的Fe^(2+)作为催化剂,紫外/电Fenton耦合转盘系统可以在45 min内将初始浓度50 mg·L^(-1)四环素降解94.2%且90 min时TOC的去除率为68.2%.紫外/电Fenton处理效果明显优于电Fenton系统.进一步实验分析发现,紫外线的引入可以通过两种途径来提升电Fenton的处理效果.一方面紫外光可以促进Fe^(3+)还原成Fe^(2+),加速体系铁离子循环,从而提升电Fenton的处理效果;另一方面还可以通过直接激发H_2O_2分解成活性自由基加速降解四环素.In this study, an electro-Fenton reactor coupling ultraviolet light and rotating disk technology was designed for the degradation of wastewater containing tetracycline. In this reactor,H_2O_2 was generated in situ from the reduction reaction of O_2 in the rotating graphite cathode,and then the H_2O_2 is decomposed into active free radicals to degradation of recalcitrant organic pollutants.The effects of p H,voltage,and rotating speed on hydrogen peroxide generation were investigated,and the maximum concentration of H_2O_2 reached 51.5 mg·L^（-1） within 75 min at pH 3,rotation speed of 400 r·min^（-1） and a potential of -0.8 V vs. SCE. The photo-electro-Fenton system showed excellent ability for degrading organic pollutants compared to the electro-Fenton system. Experimental results showed that 94.2% of tetracycline（ 50 mg·L^（-1）） was degraded in the photo-electro-Fenton system within 45 min and the TOC removal efficiency is 68. 2% in 90 min. Further experiments indicated that the ferric ions are photo-converted to ferrous ions,increasing the hydroxyl radical generation rate. In addition, the direct excitation of hydrogen peroxide into the hydroxyl radical by UV contributed to the removal of tetracycline.

关 键 词：光电Fenton 转盘技术 四环素 铁循环 

分 类 号：X703[环境科学与工程—环境工程]