Discovery and potential ramifications of reduced iron-bearing nanoparticles-magnetite, wustite, and zero-valent iron-in wildland-urban interface fire ashes

dc.contributor.authorBaalousha, Mohammeden
dc.contributor.authorDesmau, Morganeen
dc.contributor.authorSingerling, Sheryl A.en
dc.contributor.authorWebster, Jackson P.en
dc.contributor.authorMatiasek, Sandrine J.en
dc.contributor.authorStern, Michelle A.en
dc.contributor.authorAlpers, Charles N.en
dc.description.abstractThe increase in fires at the wildland-urban interface has raised concerns about the potential environmental impact of ash remaining after burning. Here, we examined the concentrations and speciation of iron-bearing nanoparticles in wildland-urban interface ash. Total iron concentrations in ash varied between 4 and 66 mg g(-1). Synchrotron X-ray absorption near-edge structure (XANES) spectroscopy of bulk ash samples was used to quantify the relative abundance of major Fe phases, which were corroborated by transmission electron microscopy measurements. Maghemite (gamma-(Fe3+)(2)O-3) and magnetite (gamma-Fe2+(Fe3+)(2)O-4) were detected in most ashes and accounted for 0-90 and 0-81% of the spectral weight, respectively. Ferrihydrite (amorphous Fe(iii)-hydroxide, (Fe3+)(5)HO8 center dot 4H(2)O), goethite (alpha-Fe3+OOH), and hematite (alpha-Fe23+O3) were identified less frequently in ashes than maghemite and magnetite and accounted for 0-65, 0-54, and 0-50% of spectral weight, respectively. Other iron phases identified in ashes include wustite (Fe2+O), zerovalent iron, FeS, FeCl2, FeCl3, FeSO4, Fe-2(SO4)(3), and Fe(NO3)(3). Our findings demonstrate the impact of fires at the wildland-urban interface on iron speciation; that is, fires can convert iron oxides (e.g., maghemite, hematite, and goethite) to reduced iron phases such as magnetite, wustite, and zerovalent iron. Magnetite concentrations (e.g., up to 25 mg g(-1)) decreased from black to gray to white ashes. Based on transmission electron microscopy (TEM) analyses, most of the magnetite nanoparticles were less than 500 nm in size, although larger particles were identified. Magnetite nanoparticles have been linked to neurodegenerative diseases as well as climate change. This study provides important information for understanding the potential environmental impacts of fires at the wildland-urban interface, which are currently poorly understood.en
dc.description.adminPublic domain – authored by a U.S. government employeeen
dc.description.notesThis work was supported by a RAPID grant (2101983) from the United States National Science Foundation (NSF) and by the Nanoscale Characterization and Fabrication Laboratory and the Virginia Tech National Center for Earth and Environmental Nanotechnology Infrastructure (NanoEarth), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), supported by NSF (ECCS 1542100 and ECCS 2025151). We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PetraIII, and we would like to thank Edmund Welter and Regina Biller for their assistance in using the beamline P65. We would like to thank Thais Couasnon, Jeff P. Perez and Roberts Blukis from the GFZ German Research Center for Geosciences as well as Akhil Tayal and Xiao Sun from DESY, for providing some of the Fe references for XAS analysis and helping with the synthesis of others. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.en
dc.description.sponsorshipRAPID grant from United States National Science Foundation (NSF) [2101983]; Nanoscale Characterization and Fabrication Laboratory; Virginia Tech National Center for Earth and Environmental Nanotechnology Infrastructure (NanoEarth) - NSF [ECCS 1542100, ECCS 2025151]; Directorate For Engineering; Div Of Chem, Bioeng, Env, & Transp Sys [2101983] Funding Source: National Science Foundationen
dc.description.versionPublished versionen
dc.publisherRoyal Society Chemistryen
dc.rightsPublic Domain (U.S.)en
dc.subjectparticulate matteren
dc.titleDiscovery and potential ramifications of reduced iron-bearing nanoparticles-magnetite, wustite, and zero-valent iron-in wildland-urban interface fire ashesen
dc.title.serialEnvironmental Science-Nanoen
dc.typeArticle - Refereeden
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
5.24 MB
Adobe Portable Document Format
Published version