Removal of Cu(II), Co(II) and Pb(II) from synthetic and real wastewater using calcified Solamen Vaillanti snail shell

In this study, bioadsorbent powder of Solamen Vaillanti snail shell was used to remove lead, cobalt, and copper ions from synthetic and industrial wastewater. To do this, bioadsorbent powder was first prepared by the calcination of shellfish skin, and the physical properties of the bioadsorbent before and after the adsorption process were then studied using Brunauer-Emmett-Teller, scanning electron microscopy, Fourier-transform infrared spectroscopy, and energy dispersive X-ray analysis techniques. Also, the effect of different parameters such as pH, contact time, temperature, the initial concentration of metal ions, and adsorbent dosage on the removal efficiency of lead, cobalt and copper ions was investigated. The best adsorption efficiency was determined as pH 6 for cobalt and pH 5 for lead and copper, the temperature of 25 degrees C, the contact time of 60 min, initial ion concentration 10 mg L-1, and adsorbent dosage of 2 g L-1. The maximum removal efficiencies of lead, cobalt, and copper ions were 94.4%, 96.5%, and 96.7%, respectively. Also, the maximum adsorption efficiency of lead, cobalt, and copper ions from industrial wastewater was obtained 85%, 81%, and 91%, respectively. The equilibrium behavior of the adsorption process indicated that the adsorption process follows the Langmuir isotherm model. Also, the pseudo-second-order kinetic model could better describe the kinetic behavior of the adsorption process. According to the Langmuir model, the highest adsorption capacity of lead, cobalt, and copper were obtained 26.04, 29.41 and 33.55 mg g(-1), respectively. The values of the thermodynamic parameters also showed that the adsorption process was feasible, spontaneous, and exothermic.