Abstract
A novel electrochemical system with corroding electrode of iron (Fec) inserted between boron-doped diamond (BDD) anode and carbon felt (CF) cathode, named BDD-Fec-CF system, was initially constructed and investigated in the present study. In this system, p-nitrophenol (p-NP) degradation was significantly enhanced in a wide pH range of 3–11 compared with BDD anode with CF cathode system (BDD-CF) and BDD anode with stainless steel (SS) cathode system (BDD-SS), respectively. Especially under acidic conditions, COD removal efficiency in BDD-Fec-CF system was achieved 89.1%, which was only 35.2% in BDD-SS system under the same conditions. The excellent performance under acidic conditions was mainly attributed to Electro-Fenton reaction. Hydroxyl radicals were formed by reaction between Fe2+ released from Fec electrode and H2O2 generated by dissolved oxygen reduction at CF cathode. Under alkaline conditions, flocs were formed to remove p-NP by coagulation besides anode oxidation, electro-generated oxidants and Fe(VI) oxidation. The fate of Fe was examined whose releasing rate was influenced by strength of electronic field and pH of solution. Under acidic conditions, Fe2+ released from Fec was oxidized into Fe3+ and then was absorbed and reduced at CF cathode. Under alkaline conditions, flocs were formed by reaction between Fe2+ and hydroxyl which came from oxygen reduction.
Original language | English |
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Pages (from-to) | 335-342 |
Number of pages | 8 |
Journal | Electrochimica Acta |
Volume | 291 |
DOIs | |
Publication status | Published - 20 Nov 2018 |
Keywords
- Boron-doped diamond
- Corroding electrode of iron
- Electro-Fenton
- Electrochemical oxidation
- p-nitrophenol
ASJC Scopus subject areas
- General Chemical Engineering
- Electrochemistry