Aqueous solution using sunflower stem, sawdust and rice husk

This study examines removal of lead from an aqueous medium using rice husk, sawdust and sunflower stem. First, the absorbents were prepared and then sieve nos. 30 and 40; particles with a mean size of 500 microns were obtained from each. The Pb(II) solution was prepared with a concentration of 25 mg/liter and absorption tests were conducted. The findings showed that the equilibrium time for rice tusk was 90 min. and for each of the other two absorbents it was 120 min. an optimal absorption pH of 6 hours was obtained for each absorbent. The tests also showed that with reduction in the concentration of the input lead, from 80 to 1mg/liter, the absorption efficiency for each absorbent increased so that the absorption efficiencies for different absorbents converged. Absorption efficiency increase with mass, too. Isothermal absorption tests showed that the Tompkins model had a better fitness than the Langmuir and Freunlich models.

کلیدواژه ها:

Rice husk ، sawdust ، sunflower stem ، Tompkins absorption isotherm ، absorption efficiency ، lead