Study on the use of roasted barley powder for adsorption of cu2+ ions in batch experiments and in fixed-bed columns

Abstract

The potential to remove Cu2+ ions from aqueous solutions through biosorption using roasted barley powder and alkalized barley was investigated in batch experiments and in fixed-bed columns. The influences of initial concentrations (40 to 600 mg/L) of the metal ion, the amount of adsorbent (0.01 to 0.25 g), the contact time (2 to 240 min), and the pH (1.0 to 5.5) were all studied. An isotherm model was applied to describe the equilibrium. The percentage of adsorption increased with increasing pH-values up to 5.5 and with dosage of adsorbent up to 0.1 g. The equilibrium adsorption capacities of Cu2+ after 3hours were 43.8 and 51.3 mg.g-1 for barley and alkalized barley, respectively. These values are higher when compared with the adsorption capacity of various adsorbents reported in literature. The adsorption data fit well to the Langmuir isotherm model, and the experimental results indicate that chemisorption onto the surface of the barley and alkalized barley is the major adsorption mechanism for binding Cu2+ ions for both sorbents.