This study was supported by the National Natural Science Foundation of China , China ( U1967210 ), the Open Fund of Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling , China ( 2020B121201003 ), and the Program for Education Department of Hunan Province , China ( 21B0405 and 21C0281 ).
This study was supported by the National Natural Science Foundation of China, China (U1967210), the Open Fund of Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, China (2020B121201003), and the Program for Education Department of Hunan Province, China (21B0405 and 21C0281). The molecular fractionation of DOM during Fe (oxyhydr)oxides transformation is a key soil process that may affect uranium behaviors. In this study, we found that the coprecipitated DOM changed Fe (oxyhydr)oxides morphology and structure during the transformation, and aliphatic molecules were selectively released, which reduced uranium adsorption on, and accelerated uranium release from Fe (oxyhydr)oxides. The changed kinetics of uranium adsorption/desorption on Fe (oxyhydr)oxides may counteract uranium stabilization in mineral-organic associations. Our results shed light on DOM molecular property as a critical driver of uranium kinetic reactions, which have significant implications for predicting uranium sequestration and transfer in soil. Supplementary data to this article can be found online.