Ecofriendly Composite as a Promising Material for Highly-Performance Uranium Recovery from Different Solutions

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Biopolymer-based materials are crucial for addressing environmental contamination by heavy metals and radionuclides.
• Chitosan, a renewable biopolymer, shows potential for developing efficient sorbent materials.
• Functionalization enhances the properties of biopolymers for specific contaminant removal.

Purpose of the Study:

• To develop and characterize a chitosan-based hydrogel functionalized with sulfonic groups for improved uranium sorption.
• To evaluate the sorption performance, kinetics, and isotherms of the functionalized hydrogel for uranium (VI) ions.
• To assess the reusability and application potential of the sorbent in real contaminated water samples.

Main Methods:

• Chitosan functionalization with sulfonic groups.
• Characterization using FTIR, nitrogen adsorption, pH_PZC, TGA, SEM, and SEM-EDX.
• Batch sorption experiments to determine optimal conditions (pH, time) and sorption capacity.
• Kinetic and isotherm modeling (PFORE, RIDE, Langmuir, Sips).
• Desorption studies and cyclic stability tests.

Main Results:

• The functionalized chitosan hydrogel exhibited efficient uranium (VI) sorption, with optimal performance at pH 4.
• Fast sorption kinetics were observed, reaching equilibrium within 25 minutes and fitting pseudo-first order and intraparticle diffusion models.
• The maximum sorption capacity was approximately 1.5 mmol U g^-1, with isotherms fitting Langmuir and Sips models.
• The sorbent demonstrated good stability over 5 sorption-desorption cycles and effective removal of uranium from an actual mining leachate sample.

Conclusions:

• Sulfonic group functionalization significantly enhances chitosan hydrogels for uranium sorption.
• The developed hydrogel is a promising, reusable sorbent for efficient removal of uranium and potentially other radionuclides from contaminated water.
• This biopolymer-based material offers a sustainable and effective solution for environmental remediation challenges.