铁碳复合材料催化电Fenton处理抗生素废水的效果和机理研究

Antibiotic wastewater treatment in electro-Fenton system catalyzed by iron-carbon composite

针对Fenton反应中Fe^(2+)和H_(2)O_(2)生成量不匹配的问题,以活性炭和硫酸亚铁为原料,采用浸泡烧结法制备了铁碳复合材料。该复合材料能够在溶液中缓释Fe^(2+),与H_(2)O_(2)的生成形成较好的匹配关系。使用SEM和XRD对材料进行表征,并探究了其在以掺硼金刚石膜电极为阳极,碳毡电极为阴极的的电Fenton系统中催化降解抗生素磺胺二甲基嘧啶(sulfamethazine,SMT)的效果,同时对体系中不同形态铁离子含量进行测定。结果表明,当材料投加量为0.02~0.2 g时,SMT降解效率均优于未投加材料的系统,随着投加量增加,反应效果逐步提升。利用量子化学计算推测了SMT反应的活性位点,结合LC-MS测试结果,推测SMT可能的降解机理,结果显示SMT通过苯胺氧化、磺胺键裂解和嘧啶环氧化等方式被逐步降解。

An iron-carbon composite material(Fe@C)was prepared using activated carbon and ferrous sulfate by immersion sintering method as electro-Fenton catalyst.The amount of Fe^(2+) released from Fe@C could match with H_(2)O_(2) formed at cathode.This composite was characterized by SEM and XRD,respectively.Degradation efficiency of sulfamethazine(SMT)in electro-Fenton system with Boron-doped Diamond anode and carbon felt cathode using Fe@C as catalyst was investigated.Results showed that the degradation efficiency of SMT increased along with the dose of Fe@C rising in the range of 0.02-0.2 g.The active sites of SMT during reaction were identified based on DFT calculation results and the possible degradation pathway was proposed by LC-MS.The degradation mechanism included aniline oxidation,sulfonamide bond cleavage and pyrimidine epoxidation.