Effect of gamma-Fe2O3 nanoparticles on the composition of montmorillonite and its sorption capacity for pyrene

Fe content and distribution on montmorillonite would probably enhance its sorption capacity for hydrophobic organic pollutants. Thus, Fe modified montmorillonites with different ratios of FeSO4 center dot 7H2O and Camontmorillonite were prepared. The results indicated that gamma-Fe2O3 nanoparticles were not only generated at the montmorillonite surfaces, but that the gamma-Fe2O3 also extended the edges of montmorillonite surfaces. The sorption capacities for pyrene were enhanced and even reached 834.79 mu g g-1 with increase in ferrous iron content, but were then suppressed due to aggregation of gamma-Fe2O3 on montmorillonite surfaces. Furthermore, pyrene was directly observed on gamma-Fe2O3-montmorillonite surfaces with a lattice spacing parameter of approximately 0.27 nm, indicating that a new phase that mainly contained pyrene was generated during the sorption process. Additionally, after regenerating the gamma-Fe2O3-montmorillonite composites, they could be reused for at least 5 cycles. It is therefore proposed that the prepared gamma-Fe2O3-montmorillonite could be exploited as a potential green composite for remediation of hydrophobic organic pollutants in soil and sediment. (c) 2021 Elsevier B.V. All rights reserved.