Organophilic clays for efficient removal of eosin Y dye properties

Abstract

organophilic local clay materials from Boyolali- Central of Java were prepared via exchange reaction with hexadecyltrimethylammonium bromide (C16TMABr) solution. These materials were used as potential agent for the removal of an acidic eosin Y dye from artificially polluted solution. Different techniques were used to characterise these materials. The uptake amount of surfactants depended on the initial surfactant loadings, different increase of interlayer spacing of clay layers were obtained due to different orientations of the intercalated surfactants. TGA and DSC data indicated that the intercalated surfactants behave differently than the pure surfactant salt, and it was supported by FTIR studies The eosin removal was operated under various conditions such as dye initial concentrations, different amounts of surfactants, solid dose, temperature, and pH. The pH of removal could be attained by modifying the eosin Y solution or the treatment of the organophilic solid by different acid or basic solutions prior adding to natural eosin Y solution. Good removal efficiencies were obtained at acidic pH below 4.The studied materials exhibited a maximum removal capacity of 78.05 mmol/kg, depending of up take amount of C16TMA cations. The removal trials were found to be endothermic and spontaneous. The reactivity of the different dye forms at different pHs values towards the organophilic clay was compared based on the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy values. The regeneration process of spent organophylic clays by a friendly method to the environment was reported and tested over seven successive cycles. Single stage adsorber design was proposed using Langmuir and balance equations, for various volumes of dye solutions at fixed initial concentration and different reduction percentages.