Adsorption of direct green B on mixed hydroxy-Fe-Al pillared montmorillonite with large basal spacing.

Through cation-exchanging of montmorillonite, mixed hydroxy Fe-Al-pillared montmorillonites with large basal spacing were synthesized. The application of these mixed hydroxy Fe-Al-pillared montmorillonites as adsorbents in the areas of environmental protection and pollution control was investigated. Adsorption of Direct Green B, an organic dye, on OH--Fe--, OH--Al--, OH--Fe--Al-- pillared montmorillonites was studied. Results showed that these pillared montmorillonites had much better adsorption properties than traditional Na-organo-montmorillonite. It was also found that pH of the solutions had great effect on the performance of these hydroxy-metal pillared montmorillonites in treating the wastewater containing Direct Green B.