The feasibility of light expanded clay aggregate (LECA) was studied as a green and low cost sorbent for removing of Acid Blue-193 (AB193) dye from synthetic colored wastewater. The effect of operating parameters such as emperature, initial concentration, initial pH, and contact time was investigated. On the basis of batch test results, the optimum operating conditions were found to be pH of 1.5, temperature of 25oC, and in range of initial concentrations 50-1000 (mg/L). The isotherm equilibrium data were fitted well by Langmuir isotherm (qmax= 71.43 (mg/g)) at 15°C. The experimental data was fitted very well with the pseudo-second-order kinetic model. The data was followed the external diffusion model up to initial 40 min and then, by intra-particle diffusion model up to 60 min, whereas diffusion is not only the rate-controlling step. Thermodynamic studies proved that AB193 adsorption process was a spontaneous, feasible, exothermic, and random process with physical adsorption mechanism.
