Montmorillonite-Alginate Gel for Basic Red 51 Adsorption and Desorption

This research focused on the synthesis of the 6 formulas of sodium alginate gel bead mixed with montmorillonite clay mineral to be used for Basic red 51 dye adsorption. The influencing factors for the adsorption were studied such as the gel bead dosage, adsorption time, initial pH, and initial concentration of dye. The concentrations of residual dye in solution were followed up by UV-vis spectroscopy. The removal efficiency of formula 6 was 97.05%. The adsorption kinetic was best fitted to pseudo-second-order reaction and the adsorption isotherm confirmed Freundlich. Then Fourier transform infrared spectroscopy technique was used to characterize the functional group of formula 6 of sodium alginate gel bead modified with montmorillonite before and after adsorption. Moreover, the adsorption-desorption isotherms of N2 gas were studied by Brunauer, Emmett and Teller technique, can be classified to type IV, indicates some degree of mesoporosity. From the desorption studies, it was found that the desorption of Basic red 51 dye from formula 3 gel beads was 36.75% using water and ethanol solution (70:30) and concentrated hydrochloric acid.