The electrocoagulation (EC) of dye-polluted aqueous solutions was considered using iron electrodes. In a novel approach, the EC process was simultaneously integrated with ultrasound (US) and H2O2 on the basis of the electro-generation of magnetite nanoparticles via sacrifice anode. Direct red 31 (DR31) dye was chosen as model pollutant. During the short reaction time of 20 min, the US/H2O2/EC process led to the highest decolorization efficiency of 93.3% compared with the US/EC (65.3%) and H2O2/EC (54.1%) processes. The real textile wastewater sample was effectively treated and mineralized by the US/H2O2/EC process (COD removal: 86.7%; TOC removal: 58.7%).