Biosorption of lead ions from aqueous solutions by beech sawdust and wheat straw

This paper presents the results of the Pb2+ adsorption from synthetic Pb(NO3)2 solutions, using the beech sawdust and wheat straw as adsorbents. Physicochemical characterization of the adsorbents included the specific surface area, pHpzc, SEM-EDS and FTIR analysis. Adsorption kinetics and isotherms, as well as changes in the pH solution during the process, were monitored and analyzed. The results showed that the adsorption is well explained by the pseudosecond order kinetic model for both adsorbents. Adsorption of the Pb2+ on sawdust and straw is well described by the Temkin isotherm, which is confirmed by the high values of the regression coefficient R2. The maximum adsorption capacity of lead ions on the beech sawdust and wheat straw was 9.9 and 9.7 mg g-1, respectively. The obtained results have indicated that the beech sawdust and wheat straw are suitable adsorbents for the adsorption of lead ions from dilute aqueous solutions.