Effects of nZVI on the migration and availability of Cr(VI) in soils under simulated acid rain leaching conditions

Hexavalent chromium, Cr(VI), is a ubiquitous toxic metal that can be reduced to Cr(III) by nano-zero-valent iron (nZVI). Finding out effects of continuous rainfall leaching on the Cr(VI) release and availability remains a problem, needing to be addressed. Whether the Cr(VI) reduction by nZVI and continuous rainfall leaching lead to localized heterogeneity in soil is unclear. Therefore, two in situ high-resolution (HR) techniques of the diffusive gradients in thin-films (DGT) and planar optode were combined with ex situ sampling experiments here. Results demonstrate that nZVI decreased Cr(VI) leaching by 5.60-8.50 % compared to control soils. DGT-measured concentrations of Cr(VI), C