摘要
过往的研究表明,引入均相/非均相还原剂或额外能量来诱导Fe(Ⅵ)形成铁活性中间体(Fe(Ⅳ)和Fe(Ⅴ))对水中污染物进行处理会导致Fe(Ⅵ)的利用率低,需要创新的活化策略.基于此,本文采用碳纳米管(CNT)/Fe(Ⅵ)体系对水中磺胺二甲基嘧啶(SMT)进行降解,并研究体系的作用机理和SMT的降解机制.研究发现,CNT可以介导从SMT到Fe(Ⅵ)的直接电子转移,CNT在体系中起电子介体而不是电子供体的作用.在50 mg·L^(-1)CNT和100.0μmol·L^(-1)Fe(Ⅵ)的作用下,5.0μmol·L^(-1)SMT能够在10 min内实现完全降解,它在该体系中的转化途径主要包括苯胺部分的氧化、磺酰胺键的断裂和Smiles型重排.另外,CNT/Fe(Ⅵ)体系在不同天然水体中都有较好的SMT去除率.本研究相关结果为活化Fe(Ⅵ)氧化污染物过程中的电子转移机制提供了新的解释.
Previous studies have shown that the introduction of homogeneous/non-homogeneous reductants or additional energy to induce Fe(Ⅵ)to form iron-activated intermediates(Fe(IV)and Fe(Ⅴ))for the treatment of wastewater contaminants leads to a low utilization of Fe(Ⅵ),requiring the development of innovative activation strategies.In this study,the carbon nanotube(CNT)/Fe(Ⅵ)system was used for the degradation of sulfamethazine(SMT)in water,and the degradation mechanism of SMT were investigated.It was found that CNT could mediate the direct electron transfer from SMT to Fe(Ⅵ),with CNT acting as an electron mediator rather than an electron donor in the system.Under the conditions of 50 mg·L^(-1) CNT and 100.0μmol·L^(-1) Fe(Ⅵ),5.0μmol·L^(-1) SMT could be completely degraded within 10 min,with the main transformation pathways including the oxidation of the aniline portion,the cleavage of the sulfonamide bond,and the Smiles-type rearrangement.Additionally,the CNT/Fe(Ⅵ)system exhibited good SMT removal performance in different natural waters.The results of this study provide new insights into the electron transfer mechanism in the activation of Fe(Ⅵ)for the oxidation of pollutants.
作者
张誉丹
吕文英
刘国光
肖震钧
张晋帆
刘德柱
巫健清
林子力
陈颖怡
刘铭浩
方政
陈平
ZHANG Yudan;LÜWenying;LIU Guoguang;XIAO Zhenjun;ZHANG Jinfan;LIU Dezhu;WU Jianqing;LIN Zili;CHEN Yingyi;LIU Minghao;FANG Zheng;CHEN Ping(Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control,Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health,School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第2期11-20,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.22176042,2207602)。
