Synthesis and characterization of non-fragmentable, robust chitosan-starch-magnetite spheres for alizarin red S and amoxicillin removal

Robust chitosan (C) 85 %-starch (S) 15 % and chitosan-starch-magnetite (CSM) spheres with 1,3,5 and 7 % of magnetite (M) were synthesized by chemical co-precipitation method. An experimental design explored the enzymatic hydrolysis of the CS spheres changing the enzyme mass percentage (10–30 %w/w), hydrolysis reaction time (2–6 h) and the hydrolysis temperature (40–60 °C), meanwhile the output variable was the Alizarin Red S (ARS) adsorption. The CS spheres were characterized by ARS adsorption (at pH 9, 30 °C and by 2 h) and using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The enzymatic hydrolysis of CS enhanced ARS adsorption. The ARS degradation in presence of H2O2 was carried out with chitosan-starch-magnetite (CSM) with 7 % of M (M7) or 5 % M (M5) at pH 9, 30 °C and 6 h. Dye removal measured as absorbance decrease as high as near 71 % was achieved. The buffer composition affects results. The spheres CSM 5 M were applied in amoxicillin removal with 5–30 mg/L, 0.5–5 mM H2O2 and 30–50 °C. UV/Visible spectrophotometry combined with spectra deconvolution demonstrated a conversion of AMOX between 15 % and 100 %. A low-cost UV/Visible method to identify amoxicillin degradation is presented. Fil: Cuevas, Ricardo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Ferreira, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentina