Mesoporous mineral columns for color removal from aqueous solutions

The removal efficiency of natural minerals (e.g., zeolite and sepiolite) from aqueous solutions of azo dyes was investigated. The adsorption of three types of reactive dyes, Black, Red, and Yellow dissolved in distilled and/or deionized water on zeolite and sepiolite have been performed using column adsorption experiments. Distilled water containing 50 mg/L dyestuff was used to identify the ability of natural mesoporous minerals and their modified forms. The adsorption results indicate that both natural sepiolite and zeolite have limited adsorption capacities of the reactive dyes but are substantially improved upon modifying their surfaces with quaternary amines (HTAB). The removal of Yellow dye showed an excellent performance in sepiolite column compared to that in zeolite column.