Removal of Acid Blue 80 from aqueous solutions using chitosan-based beads modified with choline chloride:urea Deep Eutectic Solvent and FeO

• Published in: Water resources and industry Vol. 29; p. 100195
• Main Authors: Blanco, Lucía, Martínez-Rico, Oscar, Domínguez, Ángeles, González, Begoña
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2023; Elsevier
• Subjects: Acid blue 80; Adsorption; Anthraquinone dye; Chitosan-deep eutectic solvent beads; Textile pollution mitigation; BJH; Acid blue 80; Anthraquinone dye; HBA; AB80; Ch-DES; HBD; ChCl; Textile pollution mitigation; Chitosan-deep eutectic solvent beads; BET; ILs; DES; Adsorption; FTIR; un-Ch; SEM; Ch-FeO-DES; ATR
• ISSN: 2212-3717; 2212-3717
• DOI: 10.1016/j.wri.2022.100195

An alternative chitosan-based adsorbent modified by impregnation with deep eutectic solvent (DES) choline-chloride:urea at a molar ratio 1:2 proved efficient removal of the anthraquinone dye Acid Blue 80 (AB80) from aqueous solutions, and offered enhanced adsorption capacity compared to the starting materials. The adsorption was mainly affected by initial AB80 concentration, adsorbent dosage, contact time, and slightly influenced by temperature (25–45 °C), and pH (3.5–10). The pseudo-second-order kinetic model fitted the experimental data, and pseudo-first order model fitted as well at the highest AB80 concentration, 250 mg/L. The experimental data agreed with the Langmuir isotherm model, with a maximum adsorption capacity of 61.64 mg/g at 35 °C. The process was exothermic above 100 mg/L of dye and spontaneous up to 200 mg/L (T < 35 °C). The adsorbent could be reused without further treatment at least 5 times providing ≥40% removal, whereas the dye could be efficiently recovered by NaOH desorption. Electrostatic interactions as well as physisorption could explain the adsorption behavior. [Display omitted] •Enhanced adsorption capacity of chitosan-based adsorbent by modification with a deep-eutectic solvent (DES).•Reusability of the adsorbent and improved capacity by acidic treatment.•Effective Recovery of the dye by desorption.•Anionic dye Acid Blue 80 removed from wide pH range solutions at low energy demanding conditions, extensive to other dyes.