| 摘要 |
<p>PURPOSE: Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO2, and a cheating agent is provided. CONSTITUTION: The cheating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO2 and the cheating agent comprises an oregano phosphorous cheating agent, particularly sulfur-containing oregano phosphorous cheating agents, including mixtures of cheating agents. Examples of cheating agents include monographs acid, dithiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process.</p> |
