Decoloration study for removal of water-soluble basic dye using organo-attapulgite

The organo-attapulgite was prepared using attapulgite, which is pretreated with washing and drying, with hexadecyl trimethyl ammonium bromide (HTMAB) according to the results of single factor experiments and then used as adsorbent for the removal of Basic dye from aqueous solution. Adsorption kinetics and thermodynamics of methylene blue, crystal violet and basic fuchsine onto modified attapulgite were studied through static adsorption experiments. The results are as follows: It was found that the adsorption mechanisms in the dye/organo-attapulgite system follow pseudo-second-order kinetics and film diffusion and particle diffusion are all the rate determining step; adsorption isotherm studies showed that equilibrium data fitted perfectly with Langmuir isotherm model among the temperature and concentration of the experimental stude, meanwhile, all of the adsorption are the preferential adsorption; thermodynamics of adsorption indicated the physical adsorption process is a spontaneous endothermic.