Investigation of Uranium Adsorption Behavior of Al-Doped ZnO/PVDF Nanofibers Using Response Surface Methodology

Abstract

In this study, aluminum-doped zinc oxide (Al:ZnO)/poly(vinylidene fluoride) (PVDF) composite nanofibers were synthesized via electrospinning and evaluated as adsorbents for U(VI) removal. The adsorption process was optimized using Response Surface Methodology (RSM) based on a Central Composite Design (CCD). The effects of key parameters were systematically investigated. The quadratic model developed through RSM exhibited an excellent coefficient of determination (R² = 0.9846), confirming a strong correlation between experimental and predicted values. The results indicated that pH and initial uranium concentration significantly influenced adsorption efficiency. Optimal conditions were identified at pH 5.26, temperature 59.1 °C, an initial U(VI) concentration of 124.7 mg L^-1, and an adsorbent dosage of 0.0025 g. Under these conditions, the maximum experimental adsorption capacity reached 132.7 mg/g. The adsorption behavior followed the Langmuir isotherm model, suggesting monolayer adsorption on homogeneous sites with a theoretical maximum capacity of 138.5 mg g^-1, which is in close agreement with the experimental value. Thermodynamic parameters revealed that the process was spontaneous and endothermic. These findings demonstrate that electrospun Al:ZnO/PVDF nanofiber composites are promising adsorbents for uranium remediation and emphasize the effectiveness of RSM for adsorption process optimization.

Keywords

• Adsorption
• Nanofiber
• Response Surface Methodology
• Uranium

Supporting Institution

Scientific and Technological Research Council of Turkey (TÜBİTAK)

Project Number

1001-120M235

Ethical Statement

There are no ethical issues after the publication of this manuscript

Thanks

The authors gratefully acknowledge funding from the Scientific and Technological Research Council of Turkey (TÜBİTAK) under project number 1001-120M235.

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