Chromium speciation in mildly heated Cr(VI)‐doped latosol soil

Cr(VI) chemical reduction in natural organic matter (NOM)‐bearing latosol soil was investigated under various heating conditions at ≤378 K. An enhanced Cr(VI) reduction rate has been observed for the reaction at 353–378 K. The effect of Fe(II) naturally occurring in the latosol soil on Cr(VI) chemical reduction is negligible compared with the effect of NOM. Cr(OH)₃ was quantitatively specified by X‐ray absorption spectroscopy to be the key chromium species (～80%) after ～90% of Cr(VI) was chemically reduced by NOM at 353–378 K. This study indicates a potential strategy for using the heat extracted from industrial flue gas with a heat exchanger to chemically reduce Cr(VI) in NOM‐bearing or organics‐amended soils that contain Cr(VI).