CHITOSAN-BASED BIOCOMPOSITE HYDROGELS WITH SQUID PEN PROTEIN FOR ANIONIC DYES ADSORPTION

Growing environmental concerns have spurred the search for sustainable solutions to water pollution, particularly focus-ing on the removal of persistent synthetic dyes from wastewater. Hydrogels, known for their water-absorbing capabili-ties, have emerged as promising materials for such applications. This study investigates the use of squid pen protein (SPP) and chitosan, two biodegradable and biocompatible polymers, in fabricating hydrogels for effective anionic dye removal. SPP, derived from squid pen is a marine waste product and a sustainable alternative to traditional synthetic pol-ymers. When combined with chitosan, extracted from crustacean exoskeletons, the resulting hydrogels demonstrate en-hanced dye sorption properties due to the complementary characteristics of the two materials. The study focuses on syn-thesizing and characterizing SPP-chitosan hydrogels, assessing their effectiveness in removing reactive blue 4 (RB4) and methyl orange (MO) dyes from aqueous solutions. The hydrogels achieved a maximum swelling ratio of 140.7%, with adsorption capacities of 153.85 mg/g for RB4 and 60.24 mg/g for MO. These results were characterized using Fourier-transform infrared spectroscopy, optical microscopy, and scanning electron microscopy, providing insights into the func-tional groups and surface structures involved in the dye removal process. The study also highlights that a higher cross-linker content negatively impacts adsorption performance by reducing the availability of binding sites on the protein and chitosan. The combination of SPP with chitosan potentially presents a cost-effective and environmentally sustainable alternative for wastewater treatment, offering a promising solution for mitigating water pollution through sustainable materials.