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5080552 
Journal Article 
Enhanced Perfluorooctanoic Acid Degradation by Electrochemical Activation of Sulfate Solution on B/N Codoped Diamond 
Liu, Y; Fan, X; Quan, X; Fan, Y; Chen, S; Zhao, X 
2019 
1 
Environmental Science & Technology
ISSN: 0013-936X
EISSN: 1520-5851 
53 
9 
5195-5201 
English 
30957993 
WOS:000467641800057 
Electrochemical oxidation based on SO4•- and •OH generated from sulfate electrolyte is a cost-effective method for degradation of persistent organic pollutants (POPs). However, sulfate activation remains a great challenge due to lack of active and robust electrodes. Herein, a B/N codoped diamond (BND) electrode is designed for electrochemical degradation of POPs via sulfate activation. It is efficient and stable for perfluorooctanoic acid (PFOA) oxidation with first-order kinetic constants of 2.4 h-1 and total organic carbon removal efficiency of 77.4% (3 h) at relatively low current density of 4 mA cm-2. The good activity of BND mainly originates from a B and N codoping effect. The PFOA oxidation rate at sulfate electrolyte is significantly enhanced (2.3-3.4 times) compared with those at nitrate and perchlorate electrolytes. At sulfate, PFOA oxidation rate decreases slightly in the presence of •OH quencher while it declines significantly with SO4•- and •OH quenchers, indicate both SO4•- and •OH contribute to PFOA oxidation but SO4•- contribution is more significant. On the basis of intermediates analysis, a proposed mechanism for PFOA degradation is that PFOA is oxidized to shorter chain perfluorocarboxylic acids gradually by SO4•- and •OH until it is mineralized.