半胱氨酸协同Fe(Ⅲ)活化过一硫酸盐降解氧氟沙星的效果和机制

Effeciency and mechanism of cysteine synergistic Fe(Ⅲ)activated PMS degradation of OFX

Fe(Ⅱ)活化过一硫酸盐(PMS)的高级氧化工艺可以有效地降解有机污染物,但Fe(Ⅲ)向Fe(Ⅱ)转化的缓慢速率严重抑制了其广泛应用.在这项研究中,发现将天然氨基酸半胱氨酸(Cys)加入到Fe(Ⅲ)/PMS体系中,可以加速Fe(Ⅲ)还原为Fe(Ⅱ),增强体系对氧氟沙星(OFX)的降解.同时,在Cys/Fe(Ⅲ)/PMS体系中,除了活性物质·OH、SO_(4)^(·-)、^(1)O_(2)外,还鉴定出了Fe(Ⅳ),证实OFX的降解是自由基与非自由基协同作用的结果,并且探讨了Cys/Fe(Ⅲ)/PMS体系中可能存在的催化机制,研究了阴离子(Cl^(-)、HCO_(3)^(-)、HPO_(4)^(2-))对体系降解效率的影响,为Fe(Ⅲ)/PMS体系的应用及抗生素废水的处理提供了新思路.

The advanced oxidation process mediated by peroxymonosulfate(PMS)and activated by Fe(Ⅱ)can effectively degrade organic pollutants,but the slow rate of Fe(Ⅲ)to Fe(Ⅱ)conversion severely inhibits its wide application.In this study,cysteine(Cys),a natural amino acid,is introduced into the Fe(Ⅲ)/PMS system,which accelerates the reduction of Fe(Ⅲ)to Fe(Ⅱ)and enhances the degradation of ofloxacin(OFX).Meanwhile,in the Cys/Fe(Ⅲ)/PMS system,Fe(IV)is discovered in addition to the active substances·OH,SO_(4)^(·-)and ^(1)O_(2).The possible catalytic mechanism is explored in the Cys/Fe(Ⅲ)/PMS system and the effect of anions(Cl^(‒),HCO_(3)^(‒)and HPO_(4)^(2‒))on the OFX degradation efficiency is investigated.This study provides new insight for applying the transition metals/PMS system and treating antibiotic wastewater.