Removal of Lead from Aqueous Solution by Low-Cost adsorbents

In This article removal of lead from an aqueous medium using rice husk, sawdust and sunflower stem is studied. First of all, the adsorbents were prepared and then passed through different number of sieves (no. 30 and 40) and they were obtained with a mean size of 500 μm. The Pb(II) solution was prepared with a concentration of 25 mg/l and adsorption tests were conducted. The results showed that the equilibrium time for rice tusk is 90 min and for each of the other adsorbents it was 120 min. an adsorption optimal pH was obtained 6 for each adsorbent. The experiments also showed that with reduction in the concentration of the input lead, from 80 to 1mg/l, the adsorption efficiency for all the adsorbents increased as the adsorption efficiencies for different adsorbents converged. Adsorption efficiency increases with mass increase, too. Isothermal adsorption tests showed that the Tompkins model had a better fitness than the Langmuir and Freunlich models.

Keywords:

Rice husk , sawdust , sunflower stem , Tompkins adsorption isotherm , adsorption efficiency , lead