EGCG强化Fe^(2+)/过硫酸盐体系降解金橙G的研究  

Degradation of orange G by Fe^(2+)/peroxydisulfate system with enhance of EGCG

作　　者：毕晨[1,2] 施周[1,2] 周石庆[1,2] 卜令君 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082

出　　处：《中国环境科学》2017年第10期3722-3728,共7页China Environmental Science

基　　金："十二五"国家科技支撑计划(2012BAJ24B03)

摘　　要：通过向亚铁-过硫酸盐(Fe^(2+)/PDS)体系中引入具有还原性及络合性的绿茶提取物EGCG,促进Fe^(3+)/Fe^(2+)循环,增强其对偶氮类染料金橙G(OG)的降解.实验考察了PDS投加量、OG初始浓度、溶液初始pH、Fe^(2+)投加量、EGCG投加量以及溶液中共存阴离子对该体系降解OG的影响.结果表明:单独投加Fe^(2+)、EGCG、PDS以及投加EGCG/PDS、Fe^(2+)/EGCG均不能有效地降解OG;EGCG的引入使得Fe^(2+)/PDS体系对OG的降解有了显著的提升,从30.89%上升到83.71%;OG的降解效率随着PDS及Fe^(2+)投加量的增大而增大、随着OG初始浓度的增大而减小;当EGGC投加量在10~40μmol/L时,降解效率随着其投加量的增大而增大,而当EGCG投加量大于40μmol/L时,降解效率随着其投加量的增大有一定程度的降低;与Fe^(2+)/PDS体系相比,EGCG的引入使得该体系在p H为2.0~7.0范围内均能取得较好的去除效果;体系中共存阴离子对OG的降解效率有着不同程度的抑制作用,其中PO_4^(3-)>CO_3^(2-)>Cl^-.另外,通过分别加入淬灭剂甲醇和叔丁醇,证明了体系中存在着硫酸根自由基以及羟基自由基,且硫酸根自由基占主导地位.As a kind of green tea extract with reducing and chelating properties, epigallocatechin-3-gallate（EGCG） was introduced into Fe^2＋-activated peroxydisulfate（Fe^2＋/PDS） system to accelerate the transformation from Fe^3＋ to Fe^2＋ and enhance the degradation of orange G（OG）. The effect of PDS dosage, initial concentration of OG, initial solution p H, Fe^2＋dosage, EGCG dosage, and co-existing anions on degradation of OG was investigated. The results demonstrated that Fe^2＋, EGCG, PDS alone, and EGCG/PDS, Fe^2＋/EGCG system showed poor effectiveness on degradation of OG, while the involvement of EGCG into Fe^2＋/PDS system enhanced OG degradation significantly： from 30.89% to 83.71%. Besides, the degradation efficiency of OG increased along with the dosage of PDS and Fe^2＋, and decreased with the increase of initial OG concentration. An optimum dosage of EGCG was found at 40 μmol/L and the degradation efficiency of OG performed well in a wide p H range of 2.0 ~ 7.0. The degree of inhibition from strong to weak follows the order of PO4^（3-） CO3^2- Cl^-. Furthermore, by adding two typical radical scavengers（TBA and Me OH）, hydroxyl radical and sulfate radical were identified to be responsible for OG degradation and SO4^（·-）made the predominant contribution.

关 键 词：Fe2+/EGCG/PDS 自由基 铁循环 络合 还原 

分 类 号：X522[环境科学与工程—环境工程]