Crosslinked Gelatin for Sunset Yellow Dye Removal: Synthesis, Characterization, and Adsorption Performance

Gelatin is a valuable substance that is known to have a complex 3D structure, but it has limited adsorption efficiency, which limit its application at physiological temperature. In this paper, gelatin was improved by the addition of glutaraldehyde (GTA) to enhance its ability to adsorb dye in aqueous solution. The adsorption experiments were conducted under different conditions, such as the amount of adsorbent, the concentration of the dye, and the temperature. The study found that the qe by GTA-GE (4.978 to 23.056 mg/g) and GE (4.8 to 21.333 mg/g) increased with the increase of initial dye concentrations but decreased with the amount of adsorbent. The parameters at equilibrium were at a pH of 4 and a dose of adsorbent of 100 mg in a time of 80 minutes. The dye removal efficiency ranged from 88.4 to 99.8 % for GTA-GE and 83 to 96 % for GE. The equilibrium data showed that Freundlich gave the best fit( = 0.995), showing a heterogeneous with multilayer adsorption. The kinetics of SY adsorption on gelatin were in pseudo-second order( =0.981), which represents a good sorption process. Thermodynamic analysis showed that the negative value of ΔG indicates that the process is spontaneous and possible, whereas the negative value of ΔH (-12.693 kJ/mol) means adsorption is exothermic. Negative value of ΔS (-0.021 kJ/mole.K) implies that the decrease in randomness at the solid-liquid interface rises at the time of the adsorption process. The adsorbent can be reused four times with only a slight decrease in the removal.