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

The adsorbent was characterized physically and chemically by adsorption/desorption of N 2 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.