Removal of Lead and Copper from Textile Wastewater using Egg Shells

The aim of present study was to investigate the removal of lead and copper from textile wastewater using waste egg shells in a continuous stirred tank reactor. The effect of initial pH, metal concentration, adsorbent dosage and retention time were investigated. Optimum adsorption of lead (80%) was obtained at pH 6, initial metal concentration 20 mg/L, adsorbent dosage 12.5 g/L and retention time 90 minute. Also, optimum adsorption of copper (71%) was obtained at pH 6, initial metal concentration 15 mg/L, adsorbent dosage 15 g/L and retention time 75 minute. Langmuirs, Freundlich and Temkin isotherms were used for the mathematical description of adsorption equilibrium. Langmuir isotherm showed the best fitting to the isotherm equilibrium data, with a maximum adsorption capacity (qm) of 4.33 mg/g and 3.54 mg/g for lead and copper, respectively. Results revealed that pseudo-second order adsorption kinetic equation fit the data with a high correlation coefficient (R2 more than 0.97). Based on the results of the present study, egg shells is suitable to be used for the removal of lead and copper from textile wastewater.