Chitosan-based composite films to remove cationic and anionic dyes simultaneously from aqueous solutions: Modeling and optimization using RSM

Regarding the existence of cationic and anionic dyes in the water environment developing new and effective techniques to remove them simultaneously is essential. Herein, a chitosan/poly-2-aminothiazole composite film reinforced with multi-walled carbon nanotube-Mg Al-layered double hydroxide (CPML) was created, charac-terized, and used as an effective adsorbent for methylene blue (MB) and methyl orange (MO) dyes removal from the aquatic medium. The SEM, TGA, FTIR, XRD, and BET methods were used to characterize the synthesized CPML. Response surface methodology (RSM) was utilized to evaluate dye removal based on the initial con-centration, dosage, and pH factors. The highest adsorption capacities were measured at 471.12 and 230.87 mg g-1 for MB and MO, respectively. The study of different isotherm and kinetic models revealed that the adsorption of the dyes onto CPML nanocomposite (NC) was correlated with the Langmuir and pseudo-second-order kinetic model, which indicated a monolayer adsorption manner on the homogeneous surface of NCs. The reusability experiment clarified that the CPML NC could be applied multiple times. Experimental results show that the CPML NC has sufficient potential for treating cationic and anionic dye-contaminated water.

Automated summary

Regarding the existence of cationic and anionic dyes in water, it is crucial to develop new techniques for their simultaneous removal. In this study, a chitosan/poly-2-aminothiazole composite film reinforced with multi-walled carbon nanotube-Mg Al-layered double hydroxide (CPML) was created and used as an effective adsorbent for methylene blue (MB) and methyl orange (MO) dyes removal. The synthesized CPML was characterized using SEM, TGA, FTIR, XRD, and BET methods. The highest adsorption capacities were found to be 471.12 and 230.87 mg g-1 for MB and MO, respectively. Different isotherm and kinetic models showed that the adsorption of dyes onto CPML nanocomposite (NC) followed the Langmuir and pseudo-second-order kinetic model, indicating monolayer adsorption on the homogeneous surface of NCs. The reusability experiment demonstrated that the CPML NC could be used multiple times. Experimental results suggest that the CPML NC has significant potential for treating cationic and anionic dye-contaminated water.