Sorption of methylene blue from water by organoclays

Abstract

Isotherms were measured for sorption of methylene blue by organoclays. The organoclays were prepared from kaolinite and bentonite by replacing the natural exchangable cations of the quaternary ammonium ions HDTMA (hexadecyltrimethyl ammonium),TMPA (trimethylphenyl-ammonium) and TMA (tetramethylammonium). In the adsorption experiments, Langmuir type adsorption in the Giles classification was found. Some parameters such as the equilibrium constant for adsorption (K), monolayer coverage (b), maximum fractional occupancy $(theta)$, the thermodynamic parameter free energy of adsorption $(Delta G)$ were calculated for organoclays and methylene blue systems by using the linearization method of Langmuir. Also specific surface areas of organoclays were determined from adsorption data of methylene blue. The result showed that organo-bentonites are effective sorbents for removing methylene blue from water.