氧化黄铁矿活化过二硫酸盐降解卡马西平

Activation of persulfate by oxidized pyrite for degradation of carbamazepine

黄铁矿(FeS_(2))作为一种低成本、含量丰富的天然半导体材料,被广泛用于环境污染物的催化降解.然而,黄铁矿在自然环境中极易发生氧化(氧化黄铁矿),目前关于氧化黄铁矿催化降解有机污染物活性尚不清楚.因此,以氧化黄铁矿为催化剂,卡马西平(CBZ)为目标污染物,过二硫酸盐(PDS)为氧化剂,进行氧化黄铁矿激活PDS降解CBZ的研究.实验结果表明,在氧化黄铁矿/PDS体系中,30 min内CBZ完全降解.此外,系统地探究了催化剂剂量、PDS浓度、不同pH和共存离子对CBZ降解效率的影响.通过测量溶液中浸出的铁离子和加入螯合剂证明氧化黄铁矿中溶解的Fe^(2+)和表面结合Fe^(2+)(≡Fe^(2+))均可激活PDS促进CBZ降解.淬灭实验表明氧化黄铁矿/PDS体系中产生的活性物种为SO_(4)·^(-)、HO·、O_(2)·^(-)和1O_(2),且SO_(4)·^(-)和1O_(2)在降解CBZ中起主导作用.通过循环实验与氧化黄铁矿表征相结合,证实氧化黄铁矿良好的可重复使用性.最后,阐明了黄铁矿/PDS体系中均相反应和非均相反应协同高效降解CBZ的机理.研究结果为利用天然黄铁矿去除水体新兴有机污染物提供了新的见解.

Pyrite(FeS_(2))is an abundant natural semiconductor material and has been widely used in the catalytic degradation of environmental pollutants with low-cost.However,pyrite is highly prone to oxidation(oxidized pyrite)in the natural environment,and the catalytic degradation activity of oxidized pyrite is unclear.Herein,the degradation of carbamazepine(CBZ)was investigated using oxidized pyrite and persulfate(PDS)as catalyst and oxidant,respectively.Results showed that CBZ was completely removed within 30 min in the oxidized pyrite/PDS system.In addition,the effects of catalyst dosage,PDS concentration,pH and co-presence of ions on the degradation efficiency of CBZ were systematically investigated.Through measurements of leachediron ions and the addition of chelating agents in the reaction solution,both dissolved Fe^(2+)and surface Fe^(2+)(≡Fe^(2+))from oxidized pyrite promoted the degradation of CBZ.Quenching experiments identified the active species produced in the oxidized pyrite/PDS system as SO_(4)·^(-)、HO•、O2•-and 1O2,with SO_(4)·^(-)and 1O2 playing dominant role in the degradation of CBZ.The good reusability of oxidized pyrite was confirmed through cyclic degradation of CBZ experiments and characterization of oxidized pyrite.Finally,the homogeneous and heterogeneous reaction mechanism was elucidated in the efficient degradation of CBZ by pyrite/PDS system.This research provides new insights for emerging organic pollutants removal using natural minerals.