Development of novel chitosan schiff base derivatives for cationic dye removal: methyl orange model

Adsorption of anionic reactive dye (methyl orange) onto cross-linked Chitosan derivate Schiff bases obtained from the coupling of Chitosan with 1-vinyl 2- pyrrolidone [Schiff base (I)] and 4-amino acetanilide (Schiff base (II)) in aqueous solutions was investigated using batch mode under various parameters. The structure of the prepared new Schiff bases was characterized using FT-IR and thermal gravimetric analysis. A batch experiment was conducted to study the process of Methyl orange dye adsorption from aqueous solutions using new Chitosan Schiff bases (I) and (II) comparing to cross-linked Chitosan. The influence of contact time, initial dye concentration, temperature, system pH, agitation speed, and adsorbent dosage on dye adsorption investigated. The experimental results showed that the maximum % dye removal obtained at pH 7 (pH 8 in the case of Schiff base (I)), temperature 80 degrees C, 250rpm, and contact time 70min. The adsorption equilibrium data analyzed by Langmuir and Freundlich isotherm models. Langmuir model describes the equilibrium information and fitted perfectly. The experimental kinetics data were well suited and found that the kinetics of the removal of methyl orange dye using the prepared sorbents follows a pseudo-first-order model.