Impact of iron-based nanoparticles on microbial denitrification by Paracoccus sp. strain YF1.Aquat Toxicol. 2013 Oct 15; 142-143:329-35.AT
This study investigates the effects of Fe and Fe/Ni nanoparticles on biological denitrification when using Paracoccus sp. strain YF1. Results show that adding Fe and Fe/Ni nanoparticles to the cells decreased their growth and denitrification rate. Compared to that of free cells (control 89.47%), a decrease (64.33%) in the presence of 1000 mg/L Fe/Ni nanoparticles was observed, while a small decline in the denitrification rate (76.36%) was obtained when the concentration of Fe nanoparticles was 1000 mg/L. These were further confirmed by adding Fe(2+), Fe(3+), Fe3O4, Fe(2+)/Ni(2+) and Fe(3+)/Ni(2+) individually to the free cell system. Furthermore, Fe and Fe/Ni nanoparticles influenced the nitrate removal and bacterial growth under different pH and temperature conditions. SEM, XRD and EDS demonstrated that iron oxides formed as a result of nanoparticles corrosion in biological medium. Finally the presence of nanoparticles around some bacteria was observed.