Removal of a local antiseptic dye on two solid supports by adsorption

In this research, we studied the adsorption of an Eosin B (EB) dye is a local antiseptic, available in pharmacies in the form of an active preparation on the surface of activated carbon and natural clay. Activated carbon and natural clay were characterized using various physicochemical techniques to determine the crystalline structures of the two adsorbents by DRX, and the chemical bonds by FTIR analysis, and finally, to know the maximum absorbance λmax of the dye by UV-Visible analysis. The effects of various experimental parameters, such as the effect of adsorbent mass, the initial concentration of eosin B is 1.610-4 molL-1, the contact time is 24 hours, and the pH 7 ~ 9, were studied. The removal of the dye increases with the decrease of the initial concentration of Eosin B (EB) and the contact time of the solution. The percentage of Eosin B (EB) removal increases accordingly, which arrives at 80% for activated carbon and 92% for natural clay. Langmuir and Freundlich adsorption models were used for the adsorption equilibrium descriptions. The data was very well corrected with these models. Monolayer adsorption capacities were equal to 50 mgg-1 at pH 8.3 and 25°C. Adsorption measurements show that the adsorption process is very fast and physical in nature.