Nonlinear Redox Transformations of Chromium in Soil during Wildfire Heating: The Critical Role of Iron Mineralogy.

ABSTRACT: Fire activity, including wildfires and urban fires, is increasing in frequency and severity, significantly impacting soil-borne metals such as chromium (Cr), which can be transformed from benign Cr(III) to toxic Cr(VI) during heating. However, the reaction pathway of Cr(VI) formation during wildfires remains unclear. We investigated the impacts of Fe-bearing minerals on the fire-induced formation of Cr(VI). Magnetite (Fe₃O₄) synthesized and doped with Cr(III), and Fe and Cr rich soils were heated up to 800 °C to investigate temperature-dependent transformations. For the synthetic system, Cr(III) oxyhydroxide (CrOOH) was oxidized to metastable Cr(VI) trioxide (CrO₃) up to 600 °C, which spontaneously converted to Cr(III) oxide (Cr₂O₃) wi

SUBMITTER: Namayandeh A 

PROVIDER: S-EPMC12750523 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature