Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate Ions
This paper demonstrates that intercalating Na<sup>+</sup> homoionic vermiculite with Fe<sup>3+</sup> polyhydroxy cations (1:1 molar ratio OH<sup>−</sup> to Fe<sup>3+</sup>) significantly improved the affinity of the clay mineral-based sorbent toward ph...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/12/8/1033 |
| _version_ | 1797443204330553344 |
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| author | Fernando H. do Nascimento Jorge C. Masini |
| author_facet | Fernando H. do Nascimento Jorge C. Masini |
| author_sort | Fernando H. do Nascimento |
| collection | DOAJ |
| description | This paper demonstrates that intercalating Na<sup>+</sup> homoionic vermiculite with Fe<sup>3+</sup> polyhydroxy cations (1:1 molar ratio OH<sup>−</sup> to Fe<sup>3+</sup>) significantly improved the affinity of the clay mineral-based sorbent toward phosphate. Kinetic experiments revealed that adsorption is fast, approaching an equilibrium within about 200 min of contact time, and that the rate-limiting step is the intraparticle diffusion. Adsorption isotherms fitted to the Freundlich equation and a two-site Langmuir model, consistent with the heterogeneity of adsorption sites. The separation factor derived from the Langmuir constant revealed that the adsorption was favorable and even irreversible for high-affinity minor adsorption sites. The adsorption capacity was 299 ± 63 μmol g<sup>−1</sup> (9.3 ± 2.1 mg P g<sup>−1</sup>), a value similar to several other clay-based phosphate adsorbents. Application to reservoir water spiked with 10 mg L<sup>−1</sup> in P removed about 71% of the available phosphate. |
| first_indexed | 2024-03-09T12:52:38Z |
| format | Article |
| id | doaj.art-23efd48119064e089dbea22079fb7261 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-09T12:52:38Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-23efd48119064e089dbea22079fb72612023-11-30T22:03:41ZengMDPI AGMinerals2075-163X2022-08-01128103310.3390/min12081033Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate IonsFernando H. do Nascimento0Jorge C. Masini1Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-000, BrazilDepartamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-000, BrazilThis paper demonstrates that intercalating Na<sup>+</sup> homoionic vermiculite with Fe<sup>3+</sup> polyhydroxy cations (1:1 molar ratio OH<sup>−</sup> to Fe<sup>3+</sup>) significantly improved the affinity of the clay mineral-based sorbent toward phosphate. Kinetic experiments revealed that adsorption is fast, approaching an equilibrium within about 200 min of contact time, and that the rate-limiting step is the intraparticle diffusion. Adsorption isotherms fitted to the Freundlich equation and a two-site Langmuir model, consistent with the heterogeneity of adsorption sites. The separation factor derived from the Langmuir constant revealed that the adsorption was favorable and even irreversible for high-affinity minor adsorption sites. The adsorption capacity was 299 ± 63 μmol g<sup>−1</sup> (9.3 ± 2.1 mg P g<sup>−1</sup>), a value similar to several other clay-based phosphate adsorbents. Application to reservoir water spiked with 10 mg L<sup>−1</sup> in P removed about 71% of the available phosphate.https://www.mdpi.com/2075-163X/12/8/1033eutrophicationwater treatmentadsorptionclay mineralsmontmorillonitebentonite |
| spellingShingle | Fernando H. do Nascimento Jorge C. Masini Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate Ions Minerals eutrophication water treatment adsorption clay minerals montmorillonite bentonite |
| title | Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate Ions |
| title_full | Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate Ions |
| title_fullStr | Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate Ions |
| title_full_unstemmed | Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate Ions |
| title_short | Vermiculite Modified with Fe<sup>3+</sup> Polyhydroxy Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of Phosphate Ions |
| title_sort | vermiculite modified with fe sup 3 sup polyhydroxy cations is a low cost and highly available adsorbent for the removal of phosphate ions |
| topic | eutrophication water treatment adsorption clay minerals montmorillonite bentonite |
| url | https://www.mdpi.com/2075-163X/12/8/1033 |
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