Fe-0 particles were passivated by concentrated nitric acid, and a Fe-0/(passivated Fe-0) system was setup for p-nitrophenol (PNP) removal. First, the characteristics of passivated Fe-0 particles were analyzed. The results suggest that the passivated Fe-0 particles have an iron oxide passivation film on their surface with inertness and high electrode potential (0.57 V). Besides, the optimal conditions were obtained according to the significant parameters optimization. In addition, control experiments were set up to investigate the advantage of reactivity and operational life of the Fe-0/(passivated Fe-0) system, and the results confirmed that the new system had higher reactivity and longer operational life. Meanwhile, the reaction mechanism of Fe-0/(passivated Fe-0) system for PNP removal was proposed. Finally, with an analysis of preparation cost, the Fe-0/(passivated Fe-0) system could also be seemed as a cost-effective technology. Consequently, the developed Fe-0/(passivated Fe-0) system in this study is a promising technology for treatment of contaminated water.