Hui Wu paper accepted by ACS Earth and Space Chemistry
Hui Wu and coauthors report how decade-long soil cover promotes mineral weathering and organic matter accrual in iron ore tailings while deteriorating topsoil.
Authors: H Wu, W Fu, Z Yang, C Lu, S Chen, Y Wu, Y Liu, M Wang, CW Kao, TS Chan, B Chen, S Wu
Journal: ACS Earth and Space Chemistry, 2026
Soil cover is widely used to initiate ecological rehabilitation on tailing deposits, but its influence on geochemical processes and organic matter dynamics in underlying tailings remains poorly understood. This study investigated the physicochemical and mineralogical evolution of Fe ore tailings in Hebei Province after a decade of soil cover and revegetation.
The results show that soil cover and revegetation generally neutralized alkalinity, promoted microaggregate formation, and improved organic matter stabilization in the underlying tailings. Fe K-edge X-ray absorption spectroscopy identified the transformation of primary biotite-like minerals into Fe(III) oxyhydroxides, and NanoSIMS delineated submicrometer associations between secondary Fe- and Al-bearing minerals and organic matter.
Grass rehabilitation was more effective than cropland in driving these processes. At the same time, the underlying tailings deteriorated the soil cover by increasing alkalinity and metal(loid) concentrations while lowering total organic carbon, nitrogen, and aggregate stability relative to natural soils.