碳氮包覆纳米Fe_(3)O_(4)的非自由基路径光催化去除养殖废水中四环素的机制研究  

Mechanism of Tetracycline Removal from Aquaculture Wastewater by Carbon-Nitrogen Coated Nano-Fe_(3)O_(4) Via Non-Free Radical Photocatalysis

作　　者：郑佳慧 王嘉妮 柯佳琪 何亦天 王原 黄连杨 孙启元[1,2,3] 张伟芳 ZHENG Jiahui;WANG Jiani;KE Jiaqi;HE Yitian;WANG Yuan;HUANG Lianyang;SUN Qiyuan;ZHANG Weifang(College of Environmental Science and Engineering,Fujian Normal University,Fuzhou 350007,China;Fujian Key Laboratory of Pollution Control and Resource Reuse,Fuzhou 350007,China;Research Center of Urban Waste Resource Recycling Technology and Management Engineering in Universities of Fujian Province,Fuzhou 350007,China)

机构地区：[1]福建师范大学环境与资源学院,福建福州350007 [2]福建省污染控制与资源循环利用重点实验室,福建福州350007 [3]福建省高校城市废物资源化技术与管理工程研究中心,福建福州350007

出　　处：《环境科学研究》2023年第7期1306-1316,共11页Research of Environmental Sciences

基　　金：国家自然科学青年基金项目(No.22006017);福建师范大学大学生创新创业训练计划项目(No.cxxl-2023418)。

摘　　要：养殖废水中的四环素(TC)未经有效处理,直排至水环境中将影响生态环境.本研究通过制备纳米四氧化三铁/碳氮复合材料(Fe_(3)O_(4)/CN),采用XRD、FTIR、TEM、Raman和EIS表征材料的物相组成、微观形貌和结构,并探究其光催化去除TC的性能和机理,推测TC的降解路径.结果表明:①以掺杂氮化碳的海藻酸铁水凝胶为前驱体,经高温煅烧衍生制备碳氮包覆的Fe_(3)O_(4)复合材料,该材料碳缺陷程度强,光生电子(e^(-))和空穴(h^(+))的分离效率高.②在pH=7和TC初始浓度为50μmol/L的溶液中投加0.05 g/L的Fe_(3)O_(4)/CN,且光照150 min后,TC的去除率可达95.1%.③ESR和自由基淬灭试验表明,Fe3O4/CN在光照下主要通过产生h+的非自由基路径直接氧化降解TC.④HPLC-MS测试和QSAR预测结果表明,在光催化反应中,TC发生脱氨基、开环等氧化反应,产生的降解产物对水蚤和黑头鱼的生物毒性均低于TC本身.⑤由于Fe_(3)O_(4)/CN具有良好的磁性(饱和磁化强度为13.9 emu/g),反应后的材料可通过磁铁从液相中分离.研究显示,Fe_(3)O_(4)/CN可高效去除TC,为铁氧化物/碳氮复合材料在水处理中的应用提供理论参考.Tetracycline(TC)in aquaculture wastewater will affect the ecological environment if it is discharged directly into the water environment without effective treatment.In this study,the phase composition and microstructure of the prepared nano-Fe_(3)O_(4)/carbonnitrogen composite(Fe_(3)O_(4)/CN)were characterized by XRD,FTIR,TEM,Raman and EIS,the photocatalytic performance and TC removal mechanism of the composite were explored,and the degradation pathway of TC was speculated.The results showed that:(1)Carbon nitride-doped iron alginate hydrogel was used as a precursor,it was converted into Fe_(3)O_(4)/CN by high-temperature calcination,in which Fe3O4 was encased by N-doped carbon.The material has an enhanced degree of carbon defects and a higher separation efficiency of photogenerated electrons(e^(−))and holes(h^(+)).(2)After 150 minutes of light radiation,the TC removal rate could reach more than 95.1% by adding 0.05 g/L of Fe_(3)O_(4)/CN to the solution with pH=7 and TC initial concentration=50μmol/L.(3)ESR and free radical quenching experiments revealed that TC was oxidized directly by h+generated by Fe_(3)O_(4)/CN in the presence of light in a non-radical way.(4)The results of HPLC-MS test and QSAR model showed that TC mainly underwent a series of oxidation reactions such as deamidation and ring opening in the photocatalysis.The intermediate products were less harmful to daphnia and blackheads than TC.(5)Due to the excellent magnetic properties of Fe_(3)O_(4)/CN(13.9 emu/g at saturation magnetization intensity),the material can be separated from the liquid phase by a magnet after the photocatalytic reaction.In conclusion,Fe_(3)O_(4)/CN can efficiently remove TC,which provides theoretical reference for the application of iron oxide/carbon-nitrogen composites in water treatment.

关 键 词：四环素(TC) 光催化 四氧化三铁/碳氮复合材料(Fe_(3)O_(4)/CN) 碳缺陷 降解路径 

分 类 号：X506[环境科学与工程—环境工程]