Investigation of a basic dye adsorption from aqueous solution onto raw and pre-treated sepiolite surfaces

The temperature, pH and ionic strength effects on the adsorption of crystal violet (CV) by raw, base activated and Al-saturated sepiolite samples were studied. Al-saturated sepiolite has relatively weak ability for CV adsorption compared to the raw clay, whereas the highest adsorption observed for the base activated sepiolite may be due to the Na+ ions replaced part of Mg2+ located at the edges of the channels. Different thermodynamic parameters for raw and pre-treated sepiolite samples indicate the adsorption of the dye component on a non-uniform surface.