Magnetically recyclable mesoporous carbon/zirconia composites for highly efficient removal of Cr(III) organic complexes from high salinity water: adsorption behavior and mechanism

ABSTRACT

In this study, zirconia-functionalized magnetic core-shell mesoporous carbon composites (Fe₃O₄@C-ZrO₂) were synthesized for the effective removal of Cr(III)-EDTA in high-salinity wastewater. Fe₃O₄@C-ZrO₂ with Fe₃O₄ as a magnetic core and ZrO₂ embedded in a mesoporous carbon skeleton were prepared by the sol-gel method in the nano-casting stage, which can be magnetically separated. The presence of ZrO₂ on the adsorbents enhanced the adsorption of Cr(III)-EDTA and the maximum adsorption capacity of Fe₃O₄@C-ZrO₂ was 16.21 mg·g⁻¹ at pH = 3.0, which is remarkably higher than that of Fe₃O₄@C (3.65 mg·g⁻¹). Fe₃O₄@C-ZrO₂ has a strong anti-interference capability for cations in water, which can exhibit effective adsorption properties in presence of high concentration cations and anions (80 mmol·L⁻¹) and high salt/complexant agent environments. Cr(III)-EDTA removal by adsorption of Fe₃O₄@C-ZrO₂ was mainly through the formation of ternary complexes between ZrO₂ in Fe₃O₄@C-ZrO₂ and carboxylic acid groups in Cr(III)-EDTA. The Cr(III)-EDTA saturated Fe₃O₄@C-ZrO₂ can be easily regenerated in 0.1 mol·L⁻¹ NaOH than in 0.1 mol·L⁻¹ HCl and still demonstrated an effective adsorption capacity for Cr(III)-EDTA after three repeated cycles. The results reflect the effective removal of Cr(III)-EDTA by Fe₃O₄@C-ZrO₂ in high-salinity water, providing a new method for removing heavy metals in complex water.

KEYWORDS:

• Zirconia-functionalized magnetic core-shell mesoporous carbon material
• Cr(III)-EDTA
• adsorption
• high salinity water

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability statement

Data will be made available on request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/01496395.2024.2362731

CRediT authorship contribution statement

Yuanpei Zhang: Writing original draft, Data curation, Investigation. Jiahong Wang: Writing review & editing, Supervision, Funding acquisition, Conceptualization. Jinming Huang: Writing review & editing, Formal Analysis. Zhi Hu: Project administration, Validation.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [22076111], and Key Research and Development Program of Shaanxi [2024GX-YBXM-427], China.