Journal of Inorganic Materials ›› 2021, Vol. 36 ›› Issue (3): 292-298.DOI: 10.15541/jim20200340

• RESEARCH PAPER • Previous Articles     Next Articles

Potential Induced Reversible Removal/Recovery of Phosphate Anions with High Selectivity Using an Electroactive NiCo-layered Double Oxide Film

YANG Yanyan1,2(), LI Yongguo3, ZHU Xiaowen1, DU Xiao2, MA Xuli2, HAO Xiaogang2()   

  1. 1. School of Chemistry and Environmental Science, Shangrao Normal University, Shangrao 334001, China
    2. Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China
    3. China Institute for Radiation Protection, Taiyuan 030006, China
  • Received:2020-06-20 Revised:2020-08-27 Published:2021-03-20 Online:2020-09-09
  • Contact: HAO Xiaogang, professor. E-mail: xghao@tyut.edu.cn, tyutxghao@hotmail.com
  • About author:YANG Yanyan (1983-), female, PhD, lecturer. E-mail:yangyy0927@163.com
  • Supported by:
    National Natural Science Foundation of China(21776191);National Natural Science Foundation of China(21706181);Project of Shangrao Normal University(202028);Key R&D project of Shanxi Province(201803D421094);National Key R&D Program of China(2017YFE0129200)

Abstract:

Phosphorus is an essential nutrient for organisms growth and a major cause of eutrophication in water bodies. Thus, it is crucial for both of the removal and recovery of phosphate from wastewater. In this work, the NiCo-layered double oxide (NiCo-LDO) was successfully fabricated on carbon cloth conductive substrate via the in-situ calcination of the NiCo-layered double hydroxide (NiCo-LDH) and served as the electrochemically switched ion exchange (ESIX) film electrode for the removal and recovery of PO4 3-. The performance of NiCo-LDO for PO4 3- removal by ESIX and ion exchange (IX) was compared, while the selectivity and stability of NiCo-LDO for PO4 3- removal were also investigated. The results revealed that, in (10.00±0.05) mg/L PO4 3- solution, the ion exchange quantity of the NiCo-LDO for PO4 3- removal by ESIX process was about twice over that by IX. Moreover, compared with Cl -, NO3 -, SO4 2- and I -, the NiCo-LDO exhibited much higher selectivity towards PO4 3-. In addition, the ion exchange quantity still retained 92% of its initial value after 5 uptake and release cycles. Coupled with XPS analysis, it was found that ESIX process of NiCo-LDO film electrode for PO4 3- removal and recovery mainly consisted of 3 steps, which were an irreversible “memory effect” structure recovery process, the redox reaction of metal ion in lamellar and the ligand exchange between PO4 3- and O-H groups.

Key words: NiCo-layered double oxide, phosphate, electrochemically switched ion exchange, ligand exchange

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