Synthesis of chitosan and amine functionalized MCM-41 nanocomposite for the removal of acetylsalicylic acid from water using central composite design

In this study, the synthesis of the mesoporous mobile composite material No. 41 (MCM-41) modified with 3-aminopropyltriethoxysilane (APS) and chitosan (Cs) was carried out successfully to form novel Cs/MCM-41-APS nanocomposite (NC). It was also reported that its application as an adsorbent has removed aspirin from water. The structure and morphology of NC was characterized using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Brunauer-Emmett-Teller (BET), energy-dispersive X-ray (EDX), and scanning electron microscope (SEM) techniques. Results showed that the APS (NH2) and chitosan were successfully incorporated onto the MCM-41, amine group, and Cs, which improved the properties of MCM-41. The effects of solution pH, initial aspirin concentration, adsorbent dosage, and contact time on the removal amount of aspirin were investigated and evaluated by central composite design with response surface methodology. The optimization factors in the removal process showed that the optimum removal (86%) was obtained using 3 g L-1 of adsorbent, initial aspirin concentration of 30 mg L-1, pH of 4.6, the room temperature, and 55-min time. The equilibrium data were fitted to Freundlich, Langmuir, and Temkin isotherm models. The results showed that Freundlich (R-2 = 0.997) isotherm model was the best fit model compared with Temkin and Langmuir isotherm models. Also, the adsorption process followed the pseudo-second-order kinetics model. Reuse studies revealed that the adsorbent could be regenerated and reused for adsorption cycles.