穿透式碳纳米管电极的制备及其高效降解水中抗生素的性能和机理

Efficient Degradation of Antibiotics by Flow-Through Electro-Fenton System Based on Modified Carbon Nanotubes Electrode:Performance and Mechanism

为实现水中四环素类抗生素的高效降解,本文设计开发了一种基于电活性碳纳米管(CNT)电极的穿透式电芬顿系统,采用水热法制得纳米铁和二硫化钼共修饰的CNT阴极材料(Fe-MoS_(2)@CNT),分析不同因素对电芬顿催化降解四环素性能的影响.结果表明:基于改性CNT电极的穿透式电芬顿系统对四环素表现出良好的去除性能,电压和流速等对四环素的降解动力学具有显著影响.该系统的最优试验条件:Fe掺杂量为0.3 mmol L、外加电压为-2.5 V、流速为0.85 cm^(3)(min·cm^(2)).在最优试验条件下,反应60 min内四环素的降解率可达到95%,羟基自由基为主导的活性物种.连续运行240 min后,该系统对四环素的降解率仍保持在85%以上,且在实际湖水环境水基质中对四环素降解率也可达到87.2%.研究显示,Fe-MoS_(2)@CNT膜电极具有优异的催化性能及可重复利用性,可以高效降解水中四环素类抗生素.

A flow-through electro-Fenton system based on an electroactive carbon nanotube(CNT)filter was designed and demonstrated for efficient degradation of antibiotic tetracycline.The key to this technology was a CNT cathode functionalized with iron and molybdenum disulfide(Fe-MoS_(2)@CNT).The effects of different operational parameters on the degradation of tetracycline were systematically examined.The results showed that the flow-through electro-Fenton system had an excellent performance for tetracycline degradation.The applied voltage and flow rate significantly affected the degradation kinetics of tetracycline.The optimal experimental conditions of the system were Fe loading of 0.3 mmol L,applied voltage of-2.5 V,and flow rate of 0.85 cm^(3)(min·cm^(2)).Under these conditions,the degradation efficiency of tetracycline reached 95%after 60 min reaction,and HO·was identified as the dominant reactive species.After four continuous running cycles,the degradation efficiency of tetracycline was still>85%.A removal efficiency of 87.2%could be achieved in the tetracycline-spiked lake water sample.The findings in this study demonstrate that the Fe-MoS_(2)@CNT filter has excellent catalytic performance and desirable reusability,and can be used to remove other refractory organic contaminants in water.