Carbonate composite materials for the leaching remediation of uranium-contaminated soils: Mechanistic insights and engineering applications

In this study, a composite leaching agent consisting of Na 2 CO 3 , NaHCO 3 , H 2 O 2 , and deep eutectic solvents was synthesized, and its composition and application conditions were optimized to mitigate soil contamination resulting from uranium mining. Laboratory and pilot field tests revealed that the use of this agent facilitated up to 92.6 % removal of uranium from contaminated soils. Analytical characterization through X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) revealed that CO 3 2- readily formed complexes with uranium, increasing its mobility and desorption from soil particles. The safety of the leaching process was confirmed through plant growth tests and enzyme activity assays. Moreover, the leaching strategy not only adheres to environmentally sustainable principles but also replenishes carbon and nitrogen in the soil, thereby aiding in the restoration of its functional use.