Experimental insights into anodic oxidation of hexafluoropropylene oxide dimer acid (GenX) on boron-doped diamond anodes

被引：35

作者：

Babu, Diwakar Suresh ^{[1
]}

Mol, Johannes M. C. ^{[1
]}

Buijnsters, Josephus G. ^{[2
]}

机构：

[1] Delft Univ Technol, Dept Mat Sci & Engn, Mekelweg 2, NL-2628 CD Delft, Netherlands

[2] Delft Univ Technol, Dept Precis & Microsyst Engn, Res Grp Micro & Nano Engn, Mekelweg 2, NL-2628 CD Delft, Netherlands

来源：

CHEMOSPHERE | 2022年 / 288卷

基金：

荷兰研究理事会;

关键词：

Boron-doped diamond (BDD); Hexafluoropropylene oxide dimer acid (HFPO-DA); GenX; Electrochemical oxidation; Hydroxyl radicals; Perfluorooctanoic acid (PFOA); POLYFLUOROALKYL SUBSTANCES PFASS; PERFLUOROOCTANE SULFONATE PFOS; DRINKING-WATER TREATMENT; ELECTROCHEMICAL MINERALIZATION; PERFLUOROALKYL; DEGRADATION; FATE; NANOFILTRATION; CONTAMINANTS; DESTRUCTION;

D O I：

10.1016/j.chemosphere.2021.132417

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

GenX is the trade name of the ammonium salt of hexafluoropropylene oxide dimer acid (HFPO-DA) and is used as a replacement for the banned perfluorooctanoic acid (PFOA). However, recent studies have found GenX to be more toxic than PFOA. This work deals with the electrochemical degradation of HFPO-DA using boron-doped diamond anodes. For the first time, an experimental study was conducted to investigate the influence of sulfate concentration and other operating parameters on HFPO-DA degradation. Results demonstrated that sulfate radicals were ineffective in HFPO-DA degradation due to steric hindrance by -CF3 branch. Direct electron transfer was found as the rate-determining step. By comparing degradation of HFPO-DA with that of PFOA, it was observed that the steric hindrance by -CF3 branch in HFPO-DA decreased the rate of electron transfer from the carboxyl head group even though its defluorination rate was faster. Conclusively, a degradation pathway is proposed in which HFPO-DA mineralizes to CO2 and F- via formation of three intermediates.

引用

页数：10