Hydrogel beads based on oxidized corn starch cross-linked with gelatin for tartrazine adsorption from aqueous environments

Noble hydrogel beads based on gelatin and oxidized corn starch were synthesized, and their usefulness and feasibility in treating effluent with dyes were studied in this work. Tartrazine was introduced as a model material. The kinetics of the tartrazine adsorption of the hydrogel beads were of a pseudo-second-order, and its adsorption isotherm is better fitted with the Langmuir model in comparison with the Freundlich model. With a pH of 2.5 coupled with a stirring speed of 400 r.p.m. and bath temperature of 35 °C, a maximum adsorption capacity of 293 mg g−1 was achieved. The hydrogel beads were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The results revealed that the blends have a uniform porous structure and can form stable Schiff base structures. The blend also had good stability and compatibility on mixing with electrolyte solutions, and swelling behavior measurements revealed that the hydrogel beads had excellent water-absorbing capacity.