The adsorption study of Royal Blue Tiafix and Black Tiassolan dyes using bone char as adsorbent

In this study, the potential of bone char for Royal Blue Tiafix and Black Tiassolan dyes adsorption from aqueous solutions was evaluated. The adsorbent was characterized physically and chemically by adsorption/desorption of N₂ at 77 K, scanning electron microscopy, X-ray diffraction, and infrared spectroscopy. The equilibrium adsorption results for bone char can be successfully modeled by the Langmuir and Freundlich isotherms. Pseudo-first-order and pseudo-second-order models were used to describe the kinetic data and rate constants were evaluated. Kinetics of each dye was found to follow pseudo-second-order rate kinetic model, with great correlation (higher than 0.99). In order to reduce the number of experiments to achieve better dye removal efficiency, a 2³ full factorial design with three central points and six axial points was applied in the equilibrium experiments. The variables analyzed were agitation, temperature, and pH.