Assessing the Ability of Populus sp. Sawdust in Removal of Heavy Metals Pb(Ⅱ), Ni(Ⅱ) and Cr(Ⅲ) from Wastewaters

摘要

In this paper we study the ion adsorption of heavy metals Pb(Ⅱ), Ni(Ⅱ) and Cr(Ⅲ) from wastewaters by poplar tree (Populus sp.) sawdust. For this purpose, first the wastewaters containing heavy metals were prepared in laboratory, and then by adding the sawdust to the medium, the ion adsorption by the particles of sawdust were investigated in different pH, contact times, and concentrations in wastewater. Our findings showed that with the increase of the pH value of synthetic wastewater, ion adsorption by sawdust particles was increased where in pH=5, it reached its maximum value. The highest rate of adsorption was observed in 200 mg/L concentration. Also, the adsorption rate was dependent on the type of metal. According to obtained results, the increase in the contact time raises the ion adsorption where the optimal contact time was 90 min.