Biopolymer‐Based Grafted Beads for Antibiotic Removal: Role of Itaconic Acid in Stability and Recyclability

ABSTRACT This study focuses on the preparation, characterization, and application of grafted gellan gum (GG) beads as a bio‐adsorbent for removing ampicillin (Amp), an antibiotic. Cross‐linked GG beads were prepared using the ionotropic gelation method and grafted with acrylic acid (AA) and itaconic acid (IA). The graft yields of the copolymeric GG‐g‐AA and GG‐g‐IA beads were 58% and 49%, respectively. The GG‐based beads were characterized using FTIR, DSC, and SEM. The specific surface areas and pore volumes were examined via gas sorption analysis. The impacts of adsorbent dosage, initial Amp concentration, and contact time on the adsorption were studied. The Amp removal capacities of the ungrafted GG beads, grafted GG‐g‐AA beads, and grafted GG‐g‐IA beads were determined to be 318, 354, and 349 mg g −1 , respectively. The adsorption characteristics of the GG‐based beads were examined by studying their adsorption isotherms, adsorption kinetics, and thermodynamics. Predictions were made about the adsorption mechanism based on experimental results and literature. Adsorption–desorption studies were performed to determine the reusability of bio‐adsorbents. It was found that the grafted GG beads could be reused at least five times with approximately 70% efficiency for Amp adsorption from aqueous solutions.