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Selective removal of Sr(II) from saliferous radioactive wastewater by capacitive deionization.
- Source :
-
Journal of Hazardous Materials . Jun2022, Vol. 431, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
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 (–SO 3 -) provided SPAC with remarkable selectivity of Sr2+ ion, and illustrated the ion-swapping mechanism of Sr2+ selectivity. [Display omitted] • SPAC electrode exhibited Sr2+ selectivity of 70.65 against Na+ in molar ratio of Na+:Sr2+ as 20:1. • A maximum Sr2+ electrosorption capacity of 58.21 mg g−1 was achieved in certain condition. • High overlap of electron cloud between Sr2+ ion and –SO 3 - group provided Sr2+ selectivity of SPAC. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03043894
- Volume :
- 431
- Database :
- Academic Search Index
- Journal :
- Journal of Hazardous Materials
- Publication Type :
- Academic Journal
- Accession number :
- 155960954
- Full Text :
- https://doi.org/10.1016/j.jhazmat.2022.128591