Estimation of Adsorption Isotherm for Iron Ion on Three Different Active Carbon Types

Abstract

The purpose of this experimental study is to estimate a suitable isotherm for the adsorption of iron ions from an aqueous solution onto three different types of active carbon. Three types of active carbons were selected, they include granular activated carbon prepared from date stone (GACD), granular active carbon prepared from charcoal (GACCH), and granular active carbon bought from the market (GACM) used for home desalination unit. The experiments were performed in a batch system at a constant temperature 20 oC and pH 7. Iron solutions of different concentrations were prepared from ferrous chloride. At equilibrium, linear forms of Langmuir isotherm, Freundlich isotherm, Timken isotherm, Dubinin-Radushkevich isotherm, and Elovich isotherm were tested with adsorption data to find the best-fit model. Freundlich and Langmuir were found to be good model for GACM, Freundlich isotherm was good model for GACCH and Langmuir isotherm best fits experimental data for GACD.