REMOVAL OF COLOR FROM ACID AND DIRECT DYES BY ADSORPTION ONTO SILICA FUMES

Silica fumes, a solid waste generated From the production of iron allo ys, is used in this investigation to remove the color of persistent an d microtoxic acid and direct azo dyes. The results indicate the abilit y of silica fumes to remove color of acid and direct dyes. Silica fume s exhibited good percentage of color removal (90 to 99%) and the adsor ption of the dyes were found to be independent of system pH. Adsorptio n data fit well into the Langmuir adsorption isotherm model. Regenerat ion studies indicate the nature of adsorption to be of the type chemis orption.