Production of chitosan-based polymeric gel particles and investigation on its sorption-desorption efficiency

In this study, chitosane-based gel particles were manufactured and evaluated as a sorbent due to chitosan's positive charge (because of weak primary group) hydrophilic polymer. Polymer particles were produced by two different methods from chitosane in the study (Method of precipitation-collection/Method of emulsion crosslinking method). Finally, sorption activities of the particle were tested for basic dye solution (basic blue 41, BB41), water and fatty acid (oleic acid). In the step where the effect of sorption parameters (temperature, initial pH value, chitosan concentration, initial dye concentration, contact time, etc.) on sorption yield of BB41 dye was determined, chitosan particles produced by precipitation collection method were used. The sorption experimental data were evaluated using applying the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isotherm models. It was determined that the Langmuir was more suitable for isotherm the process. Pseudo first order, pseudo second order kinetic models were used to calculate the kinetic parameters. It was concluded that the pseudo second-order kinetic model was described the adsorption data very well. In the second step which the effect of chitosan particle production conditions on the BB41 dye molecules sorption yield was examined, the particle production conditions were investigated (cross-linker type, ratio, cross-linking time, acetylation degree of chitosan, molar mass of chitosan, etc.) under optimized sorption conditions. Emulsion of cross-linked particles was used in these step. The effect of synthesis conditions on sorption of BB41 dye was tried to be determined. In the present study, the characterization and sorption efficiency of the particles produced by two different methods were examined comparatively. The effect of crosslinking density on sorption yield of crosslinking mechanism was discussed. In addition, the effect of the degree of acetylation and molecular weight on the characteristics and sorption efficiency of chitosan-based particles were also evaluated in this study.