The performance of two commercial activated carbons, in powder (PAC) and in grains (GAC), for removal of zinc in synthetic solutions was investigated. Adsorbents were characterized using the point of zero charge (pHpzc), X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) method and Scanning electron microscopy. PAC and GAC exhibited high surface area (1147.48 m2/g- 1033.82 m2/g) and carbon content (92.54 % - 87.95 %).\r\nFor both adsorbents tested, the study of the adsorption kinetics has shown that adsorption equilibrium of zinc (10 mg/L) in the presence of 4 g/L of activated carbon reached after stirring for 3 hours with a yield of 56.72 % for PAC and 51.16 % for the GAC respectively. The kinetics of adsorption seems to follow the pseudo-second order kinetic model. Polyline curves observed in the adsorption process revealed that intraparticle diffusion was not the unique mechanism governing Zn(II) adsorption process. The Langmuir, Freundlich and Dubinin-Radushkevich models indicated a suitable fit between the experimental and isotherm data. The corresponding parameters indicated that the sorption mechanism might be physical in nature.\r\nIn binary system (Zn-Cu), the effectiveness of the treatment decreases with the increase of the initial concentration of copper (2 to 35 mg/L). The zinc retention efficiencies increase with the increase of the adsorbent dose and pH of the solution. The presence of copper leads to a decrease in the adsorption efficiency of zinc. It appears that PAC is slightly more effective than GAC in retention of Zn (II) ions.

Username
Password