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Chen P, Cheng R, Meng G, Ren Z, Xu J, Song P, Wang H, Zhang L. Performance of the graphite felt flow-through electrode in hexavalent chromium reduction using a single-pass mode. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:125768. [PMID: 33836323 DOI: 10.1016/j.jhazmat.2021.125768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
Flow-through electrodes generally outcompete traditional parallel-plate electrodes in current efficiency and mass transfer. High-performance electrode materials can be costly and complicated to fabricate, hindering their wide application. In this study, we used commercial graphite felt (GF) as the cathode of a flow-through electrochemical cell to investigate its potential in treating Cr(VI) solution through electroreduction. The flow-through design with the porous GF electrode allowed sufficient contact surface with Cr(VI) and single-pass tests demonstrated a high reduction efficiency (95~100%) [117 mg/L~3 mg/L Cr(VI)] under acidic conditions. Slow flow rate and high current promoted electroreduction of Cr(VI). The presence of other metal ions could further improve Cr(VI) reduction at low flow rates due to enhanced conductivity in dilute solutions and generation of low valent ions as reducing agents. At fast flow rates, competition of these ions for reduction decreased Cr(VI) reduction efficiency. Moreover, an acidic environment prevented the coating of an insoluble layer on the GF surface and promoted durable performance, with a lower energy consumption [0.46 kWh for treating 100 L 117 mg/L Cr(VI) solution per unit area of GF]. This work demonstrated the potential of Cr(VI) detoxification using GF cathodes in flow-through electrochemical cell.
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Affiliation(s)
- Peng Chen
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
| | - Rui Cheng
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
| | - Guangyuan Meng
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
| | - Zhiming Ren
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
| | - Jiali Xu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China
| | - Pengfei Song
- Division of Science, Engineering and Technology, Thomas Nelson Community College, Hampton, VA 23452, USA
| | - Hualin Wang
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China; National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai 200237, China
| | - Lehua Zhang
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China; National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai 200237, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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