محمدتقی قانعیان
محمدحسن احرامپوش
طاهره جاسمی زاد
منیره خیرخواه
رضا امرائی
فاطمه سهل آبادی

Introduction: Humic acids have adverse effects on the water quality, then should be removed from water resources. The aim of this study was to evaluate the effect of nitrate as a radical scavenger for removal of humic acid from aqueous solutions by electron beam irradiation. Materials and Methods: In this study, after preparation of stock humic acid solution in alkaline condition, different concentrations of humic acid (۱۰, ۲۵ and ۵۰ mg/l) were prepared. Different concentrations of nitrate (۲۵, ۵۰ and ۱۰۰ mg/l) added to humic acid samples and then absorption of samples was measured at ۲۵۴ nm by using UV-Vis spectrophotometer before and after the electron beam irradiation. This study has done at pH= ۸ and at different electron beam adsorbed dose of ۱, ۳, ۶, ۹ and ۱۵ kGy. Results: The results of this study showed that the increasing of adsorbed dose from ۱ to ۱۵ kGy, the removal efficiency of humic acid also increased. By increasing of nitrate concentration from ۲۵ to ۱۰۰ mg/l, the removal efficiency of humic acid has decreased from ۴۳.۸% to ۳۶.۶% and nitrate acts as a radical scavenger. By increasing of humic acid concentration from ۱۰ to ۵۰mg/l, removal efficiency decreased in all adsorbed doses. Kinetic analysis of our results showed that the results well fitted with the second - order reaction. Conclusion: We can conclude from this study that electron beam irradiation could be a useful process for the treatment of natural organic matter (humic acid) from surface waters.