Synthesizing of hybrid bionanocomposite materials and modeling of its use for neodymium removal from aqueous solutions

In this thesis study, alginate and chitosan coated magnetic iron oxide (Fe3O4) nanoparticles (alginate-Fe3O4, chitosan-Fe3O4) were synthesized by biosynthesis technique. Adsorption and desorption of Nd3+ into synthesized alginate-Fe3O4 and chitosan-Fe3O4 hybrid bio-nanocomposites in a fixed column was investigated using a central composite design approach (CCD) combined with response surface methodology (RSM) and its controlled desorption. The characterization of alginate-Fe3O4 and chitosan-Fe3O4 nanocomposites was performed using UV-Vis, FT-IR, TGA-DTA, XRD and SEM-EDS. The adsorption of Nd3+ ions to the synthesized and characterized biocomposite materials was investigated as a function of solution pH, solution flow rate from the column and initial Nd3+ ions concentration. Adsorption of Nd3+ on both alginate-Fe3O4 and chitosan-Fe3O4 hybrid bio-nanocomposite was determined using a fixed bed column system at optimum conditions pH 5.4, the flow rate of the solution through the column was 4.0 mL min-1, and the initial concentration of Nd3+ ions was 120 mg L-1. The maximum adsorption capacity and efficiency of alginate-Fe3O4 and chitosan-Fe3O4 bio-nanocomposites were 125.01 mg g-1, 99.8%; 99.99 mg g-1 was calculated as 99.8%. The optimization of the experimental parameters was carried out with the CCD approach, and a mathematical model for the adsorption of both alginate-Fe3O4 and chitosan-Fe3O4 Nd3+ ions was obtained from the proposed quadratic model and presented. The analysis of variance results showed that the determination coefficients of both synthesized composite materials were high when used in the removal of Nd3+ ions.