Optimization study of adsorption of crystal violet and congo red onto sepiolite and clinoptiolite

The purpose of this study was to investigate the adsorption properties of locally available sepiolite and clinoptilolite materials as adsorbents for the removal of crystal violet and congo red dye ions from aqueous solution. Previous experiments have revealed that two variables, concentration and adsorbent dosage, have a significant effect on removal efficiency. In order to find the set of operating conditions for these variables that result in the best removal efficiency, central composite design of experiments was utilized. The results showed that sepiolite is a suitable material with 99% removal efficiency for the adsorption of both crystal violet and congo red from aqueous solution. However, in spite of clinoptilolite is also a suitable adsorbent for crystal violet, removal efficiency of congo red is rather low.