Metal extraction from the artificially contaminated soil using supercritical CO2 with mixed ligands

Decontamination of Uranium-Contaminated Soil Sand Using Supercritical CO2 with a TBP–HNO3 Complex

“…Some of the samples were four years old. The sample preparation process of these four-year-old samples was almost identical to that of the current samples, except that the soil was collected in fields surrounding Daejun City, which is located in the central part of the Republic of Korea (specifically, the Korea Atomic Energy Research Institute) [4]. The amount of the reagent used in the experiment was 0.5 mL.…”

“…In the experiments, the sand was classified as follows: (1) sea sand (0.5-1.0 mm); (2) coarse soil sand (0.5-1.0 mm); (3) medium soil sand (0.2-0.5 mm); and (4) fine soil sand (less than 0.2 mm). The details of the soil sample preparation have been described previously [4].…”

“…Moreover, a large amount of secondary aqueous waste is generated during decontamination, and this waste has to be decontaminated again later. Hence, conventional soil-cleaning methods do not seem to be effective for cleaning soil because they generate secondary wastes [4,5].…”

Effective Extraction of Cr(VI) from Hazardous Gypsum Sludge via Controlling the Phase Transformation and Chromium Species

“…Generally, the hazardous solid wastes mainly consist of crystalline or amorphous inorganic compounds contaminated with highly toxic heavy metals, which are adsorbed on the surface of solid phase, entrapped in aggregated particles or incorporated into crystal lattice. , Over the last decades, many methods have been studied to extract heavy metals from solid waste, − including chemical extraction with various leaching agents, − bioleaching, , vacuum chlorinating, supercritical fluid extraction with CO 2 (SFC) , and so on. However, the widespread practical application of current methods is hindered by insufficient extract efficiency, , especially for the heavy metals in encapsulated state (including physical-entrapped and lattice-incorporated states).…”

The Extraction of Metal Contaminants using Supercritical CO2

“…However, CO2(which is a non-polar compound) has difficulty dissolving metals, which are polar. Therefore, extracting agents are required to extract metals when CO2 is used as a solvent [1][2][3][4][5]. [ Table 1] displays a summary of radioactive nuclides that typically existin contaminated clothing at nuclear power plants.…”