Removal of p-Nitrophenol in Aqueous Solution by Mixed Fe⁰/(Passivated Fe⁰) Fixed Bed Filters

Abstract

Fe0 particles were passivated by concentrated nitric acid, and a Fe0/(passivated Fe0) system was setup for p-nitrophenol (PNP) removal. First, the characteristics of passivated Fe0 particles were analyzed. The results suggest that the passivated Fe0 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 Fe0/(passivated Fe0) system, and the results confirmed that the new system had higher reactivity and longer operational life. Meanwhile, the reaction mechanism of Fe0/(passivated Fe0) system for PNP removal was proposed. Finally, with an analysis of preparation cost, the Fe0/(passivated Fe0) system could also be seemed as a cost-effective technology. Consequently, the developed Fe0/(passivated Fe0) system in this study is a promising technology for treatment of contaminated water.