Selective removal of Sr(II) from saliferous radioactive wastewater by capacitive deionization

Shuhong Xiang; Hengjian Mao; Wusong Geng; Yingsheng Xu; Hongjian Zhou

doi:10.1016/j.jhazmat.2022.128591

Selective removal of Sr(II) from saliferous radioactive wastewater by capacitive deionization

J Hazard Mater. 2022 Jun 5:431:128591. doi: 10.1016/j.jhazmat.2022.128591. Epub 2022 Feb 25.

Authors

Shuhong Xiang¹, Hengjian Mao¹, Wusong Geng², Yingsheng Xu¹, Hongjian Zhou³

Affiliations

¹ Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, PR China; Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, PR China.
² Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, PR China.
³ Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, PR China; Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, PR China. Electronic address: hjzhou@issp.ac.cn.

PMID: 35247739
DOI: 10.1016/j.jhazmat.2022.128591

Abstract

⁹⁰Sr-containing radioactive wastewater during Fukushima nuclear accident (FNA) aroused extensive consideration for its disposal. Massive coexisted Na⁺ ions seriously inhibited Sr²⁺ removal, aggravating the expenditure of radioactive wastewater treatment. Herein, a chestnut shell derived porous carbon material modified with aryl diazonium salt (ADS) of sodium 4-aminoazobenzene-4'-sulfonate (SPAC) was developed as capacitive deionization electrode for selective removal of Sr²⁺ from saliferous radioactive wastewater. Based on ADS modification, the Sr²⁺ electrosorption capacity of SPAC electrode was improved to 33.11 mg g^-1 with fast ion removal rate of 2.89 mg g^-1 min^-1, comparing with only 16.10 mg g^-1 before modification. The isothermal adsorption and kinetics by SPAC electrode fitted well with Langmuir and pseudo-second-order model, achieving a maximum Sr²⁺ electrosorption capacity of 58.21 mg g^-1, superior cycling stability, and excellent charge efficiency (77.63%). Fascinatingly, the SPAC electrode exhibited superhigh Sr²⁺ selectivity of 70.65 against Na⁺ in Na⁺-Sr²⁺ mixed solution with molar ratio of Na⁺:Sr²⁺ as 20:1. Density functional theory (DFT) simulation, combining with electrochemical and spectral analyses, revealed that the high overlap of electron cloud between Sr²⁺ ion and anionic sulfonic group (-SO₃^-) provided SPAC with remarkable selectivity of Sr²⁺ ion, and illustrated the ion-swapping mechanism of Sr²⁺ selectivity.

Keywords: Biomass derived activated carbon; Capacitive deionization; Radioactive wastewater; Selective electrosorption; Strontium.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Carbon
Electrodes
Ions
Wastewater*
Water Purification*

Substances

Ions
Waste Water
Carbon