Preparation of chitosan-ethyl acrylate as a biopolymer adsorbent for basic dyes removal from colored solutions

In this study, the chitosan-ethyl acrylate (Ch-g-Ea) as a biopolymer adsorbent was prepared and used for the removal of Basic Blue 41 (BB41) and Basic Red 18 (BR18) from colored solutions. The purified product was characterized using FTIR, 1H NMR and 13C NMR analyses. The obtained results from spectroscopic data confirmed an acceptable relation with chemical structure of Ch-g-Ea. Response surface methodology (RSM) involving a central composite design (CCD) in four factors such as pH, adsorbent dosage, time contact and temperature was successfully employed for the investigation and optimization of dyes removal process. It was found that the removal of dyes increased significantly after the modification. This can be attributed to a large number of carboxyl groups were introduced to the backbone of chitosan. The results indicated that the experimental data fitted appropriately to pseudo-second order kinetic model (R2 > 0.99). Also, the data for adsorption of two basic dyes onto Ch-g-Ea correlated reasonably well by Langmuir model (R2 > 0.98). Based on the data of present study, Ch-g-Ea can be applied as an affective biopolymer adsorbent for removal of dyes from colored solutions.