Abstract: A process for the recovery of valuable metals or their compounds from an aqueous medium, such as a metals refinery process waste solution. Metals are recovered in water-insoluble form from aqueous solutions of metal salts by contacting the aqueous solution with a killed fungus of the type commonly called molds for a period of time sufficient to convert soluble metal components in the aqueous solution to a water insoluble form sequestered by the dead fungus. After treatment, metals-containing fungus is separated from the treated aqueous medium and processed for the recovery of metal values.

Abstract: A process for recovering metals from aqueous media containing metal in solution, and especially from industrial waste water. The process includes the steps of contacting the aqueous medium with fungus for a period of time sufficient to allow the fungus to extract metal in a water-insoluble form from the solution. The metal may then be recovered from the fungus. Fungi of the species Cladosporium, Penicillium, Trichoderma, Black Mycelium and Aureobasidium, have been found to be particularly useful in the process of the present invention. The process is useful, both as a water purification process and as a metals recovery process.

Abstract: Platinum, palladium and other precious metals are recovered from aqueous media containing precious metal ions in solution by contacting the metal-containing solution with a proteinaceous material selected from the group consisting of feathers, hair, hoof meal and horn meal to collect the metals in concentrated insoluble form, and recovering metal from the proteinaceous material.

Abstract: Platinum, palladium, rhodium, ruthenium, iridium and other metals are recovered from aqueous media containing precious metal ions in solution by contacting the metal-containing solution with blood meal to collect the metals in concentrated insoluble form in the blood meal, and recovering the thus collected metals from the resulting metals-loaded blood meal.