Color removal from dye wastewater using vermiculite

Abstract

The purpose of this laboratory study was to investigate the effectiveness of vermiculite extract solutions (VES) as a coagulant and of vermiculite as an adsorbent for removal of color from dye wastewater. In coagulation experiments, it was found that VES could be applied to the treatment of dye wastewater with its contents of various cations (e.g. Mg, Fe, Al Ca Si etc.) useful for coagulation. Coagulation with VES produced less sludge at a lower coagulant dosage in comparison with to conventional inorganic coagulants. For evaluation of adsorption characteristics of vermiculite on basic dye wastewater, adsorption parameters for Langmuir and Freundlich isotherms were determined. The adsorption of the basic blue dye on vermiculite was found to conform with both isotherms. The adsorption capacity of vermiculite was found to increase with the decreasing particle size and with the increase of temperature and of intensity of agitation. The results indicate that vermiculite is an excellent adsorbent for basic blue dye wastewater and only moderately, short contact times are required to reach equilibrium at the dye concentrations investigated. Spent vermiculite can be regenerated at high temperature and then be reused The cost of applied vermiculite is 11% of that of the activated carbon.