Abstarct: In this research, Nitrate removal from urban wastewater was carried out by employing magnetic nanoparticles after stabilization by polyacrylic acid. Results of investigation on samples with volumetric ration 1 to 9, illustrated that the maximum removal obtained in 70 ppm concentration. Furthermore, by reducing pH of wastewater samples, Nitrate removal was dramatically increased. In contrast, in alkaline medium, the performance of magnetic nanoparticles decreased and the little amount of Nitrate was removed. In this study, Nitrate removal mostly was carried out in the first minutes of this procedure so that in the first 20 minutes, more than 70 % of Nitrate was removed in optimum concentration and after 60 minutes, almost the entire Nitrate was removed from wastewater sample. In the following by utilizing an experimental model, solution contained wastewater and magnetic nanoparticles crossed from 19 mT magnetic field with alternative current to collect magnetic nanoparticles from wastewater and the results showed after 60 minutes, the entire Nitrate of wastewater was carried out.