Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI)
Nanoscale zero-valent iron (NZVI) is a material that is extensively applied for water pollution treatment, but its poor dispersibility, easy oxidation, and inconvenient collection limit its application. To overcome these drawbacks and limit secondary contamination of nanomaterials, we confine NZVI s...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/15/18/3764 |
| _version_ | 1797577696900808704 |
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| author | Qi Jing Yuheng Ma Jingwen He Zhongyu Ren |
| author_facet | Qi Jing Yuheng Ma Jingwen He Zhongyu Ren |
| author_sort | Qi Jing |
| collection | DOAJ |
| description | Nanoscale zero-valent iron (NZVI) is a material that is extensively applied for water pollution treatment, but its poor dispersibility, easy oxidation, and inconvenient collection limit its application. To overcome these drawbacks and limit secondary contamination of nanomaterials, we confine NZVI supported by reduced graphene oxide (rGO) in the scaffold of sodium alginate (SA) gel beads (SA/NZVI-rGO). Scanning electron microscopy showed that the NZVI was uniformly dispersed in the gel beads. Fourier transform infrared spectroscopy demonstrated that the hydrogen bonding and conjugation between SA and rGO allowed the NZVI-rGO to be successfully embedded in SA. Furthermore, the mechanical strength, swelling resistance, and Cr(VI) removal capacity of SA/NZVI-rGO were enhanced by optimizing the ratio of NZVI and rGO. Interestingly, cation exchange may drive Cr(VI) removal above 82% over a wide pH range. In the complex environment of actual Cr(VI) wastewater, Cr(VI) removal efficiency still reached 70.25%. Pseudo-first-order kinetics and Langmuir adsorption isotherm are preferred to explain the removal process. The mechanism of Cr(VI) removal by SA/NZVI-rGO is dominated by reduction and adsorption. The sustainable removal of Cr(VI) by packed columns could be well fitted by the Thomas, Adams–Bohart, and Yoon–Nelson models, and importantly, the gel beads maintained integrity during the prolonged removal. These results will contribute significant insights into the practical application of SA/NZVI-rGO beads for the Cr(VI) removal in aqueous environments. |
| first_indexed | 2024-03-10T22:11:39Z |
| format | Article |
| id | doaj.art-adc57c1264a647fd827177606263f36f |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T22:11:39Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-adc57c1264a647fd827177606263f36f2023-11-19T12:35:28ZengMDPI AGPolymers2073-43602023-09-011518376410.3390/polym15183764Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI)Qi Jing0Yuheng Ma1Jingwen He2Zhongyu Ren3Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, ChinaFaculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, ChinaFaculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, ChinaFaculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, ChinaNanoscale zero-valent iron (NZVI) is a material that is extensively applied for water pollution treatment, but its poor dispersibility, easy oxidation, and inconvenient collection limit its application. To overcome these drawbacks and limit secondary contamination of nanomaterials, we confine NZVI supported by reduced graphene oxide (rGO) in the scaffold of sodium alginate (SA) gel beads (SA/NZVI-rGO). Scanning electron microscopy showed that the NZVI was uniformly dispersed in the gel beads. Fourier transform infrared spectroscopy demonstrated that the hydrogen bonding and conjugation between SA and rGO allowed the NZVI-rGO to be successfully embedded in SA. Furthermore, the mechanical strength, swelling resistance, and Cr(VI) removal capacity of SA/NZVI-rGO were enhanced by optimizing the ratio of NZVI and rGO. Interestingly, cation exchange may drive Cr(VI) removal above 82% over a wide pH range. In the complex environment of actual Cr(VI) wastewater, Cr(VI) removal efficiency still reached 70.25%. Pseudo-first-order kinetics and Langmuir adsorption isotherm are preferred to explain the removal process. The mechanism of Cr(VI) removal by SA/NZVI-rGO is dominated by reduction and adsorption. The sustainable removal of Cr(VI) by packed columns could be well fitted by the Thomas, Adams–Bohart, and Yoon–Nelson models, and importantly, the gel beads maintained integrity during the prolonged removal. These results will contribute significant insights into the practical application of SA/NZVI-rGO beads for the Cr(VI) removal in aqueous environments.https://www.mdpi.com/2073-4360/15/18/3764gel beadnanoscale zero-valent ironreduced graphene oxidesodium alginateCr(VI) removal |
| spellingShingle | Qi Jing Yuheng Ma Jingwen He Zhongyu Ren Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI) Polymers gel bead nanoscale zero-valent iron reduced graphene oxide sodium alginate Cr(VI) removal |
| title | Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI) |
| title_full | Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI) |
| title_fullStr | Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI) |
| title_full_unstemmed | Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI) |
| title_short | Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI) |
| title_sort | highly stable mechanically enhanced and easy to collect sodium alginate nzvi rgo gel beads for efficient removal of cr vi |
| topic | gel bead nanoscale zero-valent iron reduced graphene oxide sodium alginate Cr(VI) removal |
| url | https://www.mdpi.com/2073-4360/15/18/3764 |
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