Removal of a Cationic Dye from Wastewater by Low-cost Kaolin

This study investigated the potential use of a low-cost inorganic powder (Iranian kaolin) for removal of C.I. Basic Yellow 28 (BY28) from aqueous solution. Kaolin was characterized by laser particle size analyzer (PSA), scanning electron microscopy(SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. The effect of adsorbent dosage, dye concentration, contact time, wastewater volume, initial pH and the presence of different electrolytes were studied. Experimental results revealed that kaolin is a very strong and fast adsorbent and the presence of different electrolytes and pH changes do not have a notable effect for cationic dye removal. The experimental data were correlated reasonably well by the adsorption isotherm of the Langmuir. It was found that the adsorption of BY28 on kaolin followed the pseudo-second order equation which indicates that the adsorption process is chemisorption controlled. J. Color Sci. Tech. 3(2009), 145-155 © Institute for Color Science and Technology.