Open Access Received: 24 June 2026   |   Accepted: 21 August 2026   |   Published: 07 September 2026

MICROWAVE-ASSISTED CITRIC ACID FUNCTIONALIZATION OF CELLULOSE DERIVED FROM TEXTILE WASTE FOR ENHANCED HEAVY METAL ADSORPTION

Imomjon I. Sharibov¹, Sherzod A. Yuldoshov¹, Abdushukur A. Sarymsakov¹, Bakhriddin Zh. Kholturaev¹, Ilkhom Sh. Goyibnazarov¹, Anvar A.Abdumajidov²

¹ Institute of Polymer Chemistry and Physics, Academy of Science of the Republic Uzbekistan, Abdulla Kadiriy Street 7b, 700011 Tashkent, Uzbekistan
² Tashkent Institute of Textile and Light Industry, Tashkent, Uzbekistan

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Abstract. The conversion of textile industry waste into valuable functional materials represents one of the most promising approaches to addressing contemporary environmental challenges and ensuring the rational use of resources. In this study, cellulose extracted from textile waste was modified in the presence of citric acid using microwave irradiation, resulting in the synthesis of highly functional sorbents designed for the efficient removal of heavy metal ions. The synergistic effect of microwave irradiation and thermal treatment significantly enhanced the efficiency of the modification process and enabled the incorporation of additional carboxyl groups (-COOH) into the cellulose macromolecule. As a result, the density of functional groups reached 4.43 mmol/g, which is considerably higher than that achieved by conventional thermal modification methods. The structure and chemical composition of the obtained sorbents were characterized using FTIR spectroscopy, and the results confirmed the formation of ester bonds as well as the successful introduction of additional carboxyl functional groups. The sorption properties of the synthesized materials were comprehensively investigated toward Cu(II) ions under various conditions, including initial concentration, solution pH, contact time, and temperature. The results demonstrated that the sorption capacity reached up to 250 mg/g, with the optimal condition determined at pH = 5.5. Kinetic analysis revealed that the sorption process follows a pseudo-second-order model (R² = 0.9995), indicating that the process is predominantly governed by chemical interactions involving functional groups. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models, confirming the highly efficient binding of metal ions on the sorbent surface and favorable adsorption behavior. The enhanced sorption performance is mainly attributed to the increased density of carboxyl (-COOH/-COO-) functional groups and the formation of a structurally favorable active surface induced by microwave treatment. This study demonstrates that textile waste can be effectively converted into low-cost, environmentally friendly, and highly efficient cellulose-based sorbents, highlighting their significant potential for practical applications in industrial wastewater treatment and the removal of heavy metal ions.

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Key words. Cellulose, textile waste, citric acid, microwave modification, carboxyl groups, sorption, heavy metals, adsorption kinetics, isotherm


DOI: 10.66640/UJP-2026-5-00014

*Corresponding author: Imomjon I. Sharibov, Institute of Polymer Chemistry and Physics, Academy of Science of the Republic Uzbekistan, Abdulla Kadiriy Street 7b, 700011 Tashkent, Uzbekistan

Citation: Imomjon I. Sharibov, Sherzod A. Yuldoshov, Abdushukur A. Sarymsakov, Bakhriddin Zh. Kholturaev, Ilkhom Sh. Goyibnazarov, Anvar A.Abdumajidov, MICROWAVE-ASSISTED CITRIC ACID FUNCTIONALIZATION OF CELLULOSE DERIVED FROM TEXTILE WASTE FOR ENHANCED HEAVY METAL ADSORPTION. Uzbekistan Journal of Polymers, Vol. 5(3) 2026: pp.5-21. DOI: 10.66640/UJP-2026-5-00014

©2026 Uzbekistan Journal of Polymers