Redox-active cerium dioxide nanoparticles for mitigating anthracene contamination: Promising solution to polycyclic aromatic hydrocarbon remediation in stormwater-affected soils

Due to the pressing environmental issue of polycyclic aromatic hydrocarbon (PAH) contamination in stormwater, top surface soil amendment by rare-earth-based nanoparticles was investigated as an effective remediation strategy. Here, the amendment of cerium dioxide (CeO₂) nanoparticles (CeO₂-NPs) into topsoil were studied to understand their role in mitigating anthracene contamination. Leveraging the redox activity of CeO₂-NPs, this research demonstrates their capability to adsorb/degrade anthracene, thereby reducing its bioavailability and mobility within the soil. X-ray photoelectron spectroscopy (XPS) and Energy Dispersive X-ray Spectroscopy (EDS) analyses confirmed the homogeneous distribution of CeO₂-NPs and revealed the altered chemical states of carbon, indicative of interaction with anthracene and the soil matrix. Further adsorption studies and soil column tests of four concentrations of anthracene (0, 5, 10, 15 mg/L) revealed their adsorption onto CeO₂-NPs. Further, size distribution, zeta potentials, and TEM images documented the efficiency of this strategy by over 60 %. The role of soil organic matter in the presence of anthracene was further investigated to understand their reciprocal impact on the physiochemical properties of CeO₂-NPs. We extended this analysis by incorporating genomics-based approaches, assessing alterations in community taxonomic structure and function through 16S rDNA profiling and heatmap of microbial diversity as affected by NPs or anthracene. This study enhances our understanding of nanotechnology's potential for environmental remediation of contaminated stormwater run-off.