Abstract
In this study, the adsorption of quinalizarin by natural and mesoporous acid activated palygorskite has been examinated in order to remove coloured textile dyes from non aqueous solutions. The adsorption of quanilizarin from ethanol solution onto acid activated palygorskite was followed by UV-Visible measure- ment. The adsorption capacity was largely improved when the clay was activated by HCl. The high adsorp- tion extents were observed from 2M8h to 2M 35h acid treated palygorskite samples. Adsorption isotherms of quinalizarin on acid activated palygorskite were determined and correlated with common isotherm equations such as Langmiur and Freundlich models. It was found that i/the adsorption isotherm exhibits two plateaus ii/ no model fit the isotherm data. In order to explain the adsorption behaviour of quinalizarin from ethanol onto palygorskite, the presence of stronger and weaker adsorption sites was suggested and checked by using the modified Langmuir model.