Abstract

~Removal of heavy metals from wastewater samples through the application of electron beam (EB) radiation in the presence of formate ion as the hydroxyl radical scavenger, and TiO2 nanopowder as the adsorbent and/or photocatalyst is proposed. The effect of some experimental parameters, such as radiation dose of EB, amount of TiO2 and solution initial pH, on the removal efficiency of Cd(II), Pb(II) and Cr(VI) metal ions was studied. Aqueous solutions of metal ions with pH value of 7.0 were irradiated by EB in the presence and absence of TiO2. The obtained results revealed that the removal efficiencies of Cd(II), Pb(II) and Cr(VI) ions were 71.0% (±2.6%), 84.0% (±2.3%) and 83.0% (±1.5%), respectively, by applying 6 kGy dose in the absence of TiO2. The addition of 0.9 g L–1 TiO2 to the metal ions solutions showed an enhancement in the removal efficiencies (96.0% (±3.8%), 99.1% (±2.7%) and 94.0% (±1.8%), respectively) with the same (6 kGy) radiation dose. Furthermore, it was observed that the required radiation dose to achieve the similar removal efficiencies decreased to 3 kGy in the presence of TiO2, indicating the synergistic effect through the combination of EB and TiO2. Finally, the method was applied to the oil refinery and the paint industrial effluents as the real wastewater sources, successfully.