Preparation of Calcium Alginate-Based CA-g-poly (MLA-co-VBS)/Citrullus Colocynthis Hydrogel Nano Composites: And their Application Towards Dye Adsorption

Large amounts of dyes are found in sewage, rivers, and lakes as a result of the common usage of those stains in paper, paint, cloth tanning, and several industries. Therefore, to make the water fit for human consumption, we need to find a way to remove these dyes. Through the goal of sequestering toxic Brilliant Green (BG) dyestuff just as a cationic dye model, a highly absorbent polymer known as calcium alginate-g-Poly (Fumaric acid-co-calcium 4-vinyl benzenesulfonate)/Citrullus colocynthis (Complex A) hydrogel was created via grafting that is free-radical co-polymerization. The prepared hydrogel’s surface shape, morphology and composition were assessed and characterized by using six types of parameters: FTIR, XRD, FESEM, EDX, TEM and TGA analytical techniques. The best compounding conditions were chosen to produce the hydrogel with the highest possible swelling rate. As noted in the results, the compound has the highest amount of capacity in the water that is distilled, at 3,400%. It was found that the hydrogel’s monomer VBS level significantly affected the polymer’s ability to adsorb dye, which contributed to the swelling process. Through the elements that determine the rate of chemical absorption, film diffusion,n and intra-particle absorption, the absorption capacity of BG is greatly enhanced by the porosity of the prepared hydrogel balls. By using temperature, pH, thermodynamic adsorption, zero-point charge, kinetic models and adsorption isotherms to remove BG from the aqueous solution, the effect of the absorbent material was examined. Additionally, Complex (A) showed a great ability to absorb and remove BG dye and the possibility of reuse again, which indicates a great possibility of using it as an absorbent material and removing dyes from aqueous solution. This was proven by repeating the absorption-desorption cycle more than four times. HIGHLIGHTS A novel hydrogel (Complex A) was synthesized from calcium alginate-g-poly(Fumaric acid-co-VBS)/Citrullus colocynthis. The hydrogel exhibited an exceptional swelling capacity of 3,400% in distilled water. Brilliant Green dye adsorption was significantly influenced by monomer composition and porosity. Adsorption followed film and intra-particle diffusion mechanisms, enhanced by pH and temperature control. The hydrogel showed excellent reusability, maintaining performance after 4+ absorption-desorption cycles. GRAPHICAL ABSTRACT