Magnetic Nanocomposites Containing Low and Medium-Molecular Weight Chitosan for Dye Adsorption: Hydrophilic Property Versus Functional Groups

Azo dye removal from polluted water is vital a sustainable viewpoint. In this study, we investigated the influence of chitosan molecular weight on adsorption basic blue 41. Nanocomposite (NC(M)) was prepared using magnetite nanoparticles modified by amino-silica, medium-molecular chitosan, diethylenetriaminepentaacetic acid and graphene oxide. FT-IR, XRD, FESEM, TEM, EDX, elemental mapping, TGA/DTG, VSM N2 adsorption/desorption isotherm were applied to characterize NC(M). Its effectiveness for compared with adsorbent having low-molecular (NC(L)) (Asadabadi 2021). regard, effect initial pH, temperature concentration Central Composite Design. The maximum percentage 31% NC(M) at optimum conditions. An increase in monomer number caused contact angle decrease hydrophilic property Thus, it had very low adsorption. However, NC(L) led 95%. It proposed that adsorbed coulumbic attraction, π-stacking interactions H-bonding. kinetics data satisfactorily fitted pseudo-n-order model. About 30 min necessitated reaching equilibrium rate-limiting steps changed film diffusion intra-particle as time passed. Langmuir–Freundlich best model reproduce capacity equal 55.87 mg·g−1. Besides, recovered seven times without dramatic changes its efficiency.