Synthesis of Chitin-Ionic Liquid Beads as Potential Adsorbents for Methylene Blue

The adsorption of methylene blue (MB) by chitin-ionic liquid beads was carried out with three different types of ionic liquids (ILs); 1‒butyl‒3‒methyl imidazolium acetate (BMIM Ac), 1‒butyl‒3‒methyl imidazolium chloride (BMIM Cl), and 1‒allyl‒3‒methyl imidazolium bromide (AMIM Br). These three ILs were used to investigate the compatibility with chitin in forming adsorbates for MB adsorption. Batch adsorption experiments were conducted to investigate the optimum parameters such as pH, MB initial concentrations, adsorbent dosage, and contact time for adsorption of MB. The kinetic study revealed that pseudo-second order was the appropriate kinetic model for all the synthesized chitin-ILs, whereas Langmuir isotherm gave the best isotherm model for describing the adsorption mechanism of the chitin-ILs towards MB. The calculated qmax for the chitin powder, chitin-BMIM Ac beads, chitin-BMIM Cl beads, and chitin-AMIM Br beads were 22.37 mg g-1, 19.81 mg g-1, 18.80 mg g-1, and 13.79 mg g-1, respectively.