Removal of reactive blue 221 and acid blue 62 anionic dyes from aqueous solutions by sepiolite

The removal of reactive blue 221 and acid blue 62 anionic dyes onto sepiolite from aqueous solutions has been investigated using parameters such as calcination temperature, pH, ionic strength and temperature. After 200 °C calcination temperature, the specific surface area of sepiolite decreased with increasing calcination temperature. The amount adsorbed of reactive blue 221 and acid blue 62 on sepiolite increased with increasing ionic strength and temperature, and decreasing pH. The sepiolite sample calcinated at 200 °C has a maximum adsorption capacity. However, calcination at higher temperature caused a decrease in the amount adsorbed of dye. It was found that the Freundlich isotherm appears to fit the isotherm data better than the Langmuir isotherm. Furthermore, it can be said that sepiolite has a considerable potential as an adsorbent for dyestuffs in a commercial systems.