Chromium transformations and biological impacts in aquatic systems: From sediment-water interfaces to food web complexity.

Chromium (Cr), as a dual-state pollutant that is both essential (Cr(III)) and highly toxic (Cr(VI)), has attracted considerable attention for its environmental behaviour and biological effects in aquatic ecosystems. This review systematically analyses its speciation transformation, bioaccumulation and toxicity mechanisms based on the latest advances in multi-interface processes. Natural and industrial activities annually introduce approximately 1.

Dual pathways of Mn oxide-driven Cr(III) release and transport in serpentine topsoil: OM-Cr(III) colloids and Cr(VI).

Geogenic Cr(III) oxidative release in serpentine soils is a continuous source of Cr contamination in surface and groundwater. Although manganese (Mn) oxides have been shown to be a key factor driving Cr(III) oxidative release, their oxidative mechanism and release fluxes in serpentine soils remain unclear. In this study, the dual mechanism of δ-MnO regulating Cr release and migration from surface soil was revealed through column leaching experiments.