Effect of Fe₂O₃ Nanoparticles on the Efficiency of Anammox Process

Nanotechnology plays an increasingly important role in the economy and human life, which means that more and more amounts of nanosubstances, including nanoparticles of metal oxides, together with wastewater, end up in the environment. This study aimed to study the impact of iron(III) oxide nanoparticles (n-Fe₂O₃), which have magnetic properties, on the efficiency of the Anammox wastewater treatment process. The results indicate that n-Fe₂O₃ in the range of low concentrations may have a positive effect on nitrogen metabolism, increasing the efficiency of NH₄-N removal to 98% in 120 min and at 30 °C. During the first 30 min of the process, when almost anaerobic conditions arose, nanoparticles of Fe₂O₃, stabilized the system by producing ROS. However, a constant control of TOC and pH is necessary because of the constant increase in the amount of organic compounds and H⁺ ions during the reaction. However, a longer contact of n-Fe₂O₃ with biomass causes the efficiency to decrease, and, as a result, the efficiency is lower compared to the system containing only Anammox.