Adsorption of Naphthol Blue Black Dye onto Acid Activated Titania Pillared Bentonite: Equilibrium Study

摘要

The synthesis of acid activated titanium dioxide-pillared bentonite (TiO2-pillared bentonite) and its adsorption properties on napthol blue black (NBB) dye has been studied. Natural bentonite was activated by using hydrochloric acid solutions and was intercalated with tetraisopropyl orthotitanate as titanium dioxide precursor. The as-prepared materials were characterized by X- ray Diffraction (XRD), nitrogen adsorption-desorption isotherms and Scanning Electron Microscopy Energy Dispersive X-ray Analysis (SEM-EDX). Napthol blue black dye removal was seen to increase with increasing contact time and the adsorption capacity of acid activated TiO2-pillarred bentonite was depending on the pH, initial dye concentration and the amount of adsorbent. The optimum condition of NBB dye adsorption was found at a pH of 3.0, adsorbent amount of 0.2 g, initial dye concentration 25 mg/L for 120 minutes adsorption time. The adsorption capacity for the dye was found to be 1.496 mg/g. Adsorption of NBB onto TiO2-pillarred bentonite at these conditions followed the Langmuir and Freundlich isotherm but the value of the correlation coefficient of Langmuir isotherm (0.998) is higher than Freundlich isotherm value (0.952).