A novel electrochemically switched ion exchange system for phenol recovery and regeneration of NaOH from sodium phenolate wastewater

• Published in: Separation and Purification Technology Vol. 248; p. 117125
• Main Authors: Zhang, Xiang, Niu, Junjian, Hao, Xiaogang, Wang, Zhongde, Guan, Guoqing, Abudula, Abuliti
• Format: Journal Article
• Language: English; Japanese
• Published: Elsevier B.V 01.10.2020; Elsevier BV
• Subjects: Electrochemically switched ion exchange; Energy consumption; High salinity wastewater; Phenol; Electrochemically switched ion exchange; Energy consumption; Phenol; High salinity wastewater
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2020.117125

•Separation of the phenol and desalination could be achieved simultaneously.•Production of NaOH with this ESIX system could be realized.•The FeHCF coated electrode could work repeatedly in the series operation.•The ESIX system exhibited a very low energy consumption. An electrochemically switched ion exchange (ESIX) system was proposed as a novel electrochemical method for the treatment of high concentration phenolic sodium salty wastewater, in which a ferric ferricyanide (FeHCF) coated electrode with rigid open framework can control the insertion/extraction of sodium (Na+) ions by switching the redox state of FeHCF. It is found that this ESIX system can not only remove the phenol and desalinate the phenol-containing wastewater simultaneously, but also regenerate the FeHCF coated electrode and produce sodium hydroxide (NaOH). In the series operation, more than 79% of phenol could be removed with energy consumption of 9.677 × 10−3 kWh mol−1, and meanwhile NaOH solution with a pH of 12.84 was generated with energy consumption of 2.083 × 10−3 kWh mol−1 during the recovery process of Na+ ions. It is expected that such an ESIX system can be applied for the treatment of phenol-containing high salinity wastewater.