Enhanced extraction of methylene blue by dodecyl-methyl imidazolium dodecyl sulfate GUMBOS - magnetic alginate beads

In this study, dodecyl-methyl imidazolium dodecyl sulfonate ([C12MIm][DS]) GUMBOS were synthesized and incorporated into alginate with γ-Fe2O3 to fabricate magnetic adsorbent beads ([C₁₂MIm][DS]-beads) for methylene blue (MB) removal. Characterization via ESI-MS, FT-IR, SEM, BET, and TGA confirmed their structure and properties. The beads achieved a maximum adsorption capacity of 4.5 mg/g at pH 10 with an initial MB concentration of 500 mg/L, following pseudo-first-order kinetics and the Langmuir isotherm model. Thermodynamic studies confirmed the process was exothermic. Even after six recycling cycles, the beads retained similar morphology and an MB removal percentage of 57.6%. The beads demonstrated high adsorption efficiency (70%) in the presence of Cu2⁺, ibuprofen, and malachite green, comparable to MB removal alone. These results highlight the potential of [C12MIm][DS]-beads as effective adsorbents for water remediation applications. [Display omitted] •1-dodecyl-3-methylimidazolium dodecyl sulfate GUMBOS were synthesized and characterized through FT-IR, ESI techniques.•A reusable magnetic adsorbent was developed with [C12MIm][DS] GUMBOS, γ-Fe2O3, and alginate.•[C12MIm][DS]- beads achieved 4.5 mg/g max adsorption capacity for MB at 500 ppm under different conditions.•Adsorption followed the Langmuir model and pseudo-second-order kinetics, indicating monolayer chemisorption.•[C12MIm][DS]-beads showed ∼70% MB removal in the presence of other contaminants and another dye.•[C12MIm][DS] beads maintained 70.9% efficiency on first use, reducing to 50.6% after six adsorption cycles.