Document Type: Original research article
Department of Chemistry, Payame Noor University (PNU),19395-4697, Tehran, Iran
Department of Chemistry, Islamic Azad University, Kerman, Iran
The present study shows that the eggshell powder can be used as a natural adsorbent for the removal of alizarin (1,2-dihydroxyanthraquinone) and 2-aminoanthraquinone from aqueous solutions. Experiments were carried out as a function of contact time, concentration, temperature, pH and dosage. The amount of dye uptake was found to vary with increasing initial solution pH and maximum adsorption was observed at pH=7. The equilibrium was attained in 30 min. The amount of dye uptake (mg/g) was found to increase with increase in dye concentration and contact time. The percent of adsorption was found to decrease with increase in amount of adsorbent. The data were fitted with the Langmuir and Freundlich equations to describe the equilibrium isotherms.