Adsorptive removal of anionic dye from aqueous solutions by Algerian kaolin: Characteristics, isotherm, kinetic and thermodynamic studies

Experimental investigations were carried out using available Algerian kaolin as alternative adsorbent for removal of toxic anionic dye namely Congo red from aqueous solutions. The effect of contact time, initial dye concentration, pH and temperature were experimentally studied in batch mode to evaluate the adsorption capacity, kinetic and equilibrium. Experimental results revealed that optimal adsorption took place at basic pH and high dye concentration. The dye uptake process obeyed the pseudo second order kinetic expression and was best described by the Langmuir isotherm. Thermodynamic studies showed congo red adsorption on Algerian kaolin was exothermic and spontaneous in nature. The results indicate that this local kaolin could be employed as low-cost alternative for removal of anionic dyes from industrial wastewater