Swine wastewater was treated using an ion-exchange biological reactor after an electron beam irradiation. Organic matter and nutrient in swine wastewater were pre-treated by an electron beam irradiation. The optimal dose for the solubilization of organic matter in swine wastewater ranged from 20 kGy to 75 kGy. To investigate solubilized organic fraction of swine wastewater, carbohydrates, proteins and lipids were measured. Most solubilized organic matter was proteins and lipids. The maximum chemical oxygen demand (COD) removal efficiency was 85.1% at an organic loading rate of 1.41 kg/m(3) day (75 kGy). For the removal of nitrogen, the nitrogen removal was significantly affected by the current density. The maximum total nitrogen removal efficiency was 75.0% at 1.09 A/m(2). On the other hand, amorphous phosphorus precipitation was formed in the IEBR because calcium ions competed highly with magnesium. (C) 2015 Elsevier B.V. All rights reserved.