Patents by Inventor Charles T. Hadden

Charles T. Hadden has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Conversion of inorganic ions to metal sulfides by microorganisms
    Patent number: 4789478
    Abstract: This invention relates to a process for reducing the concentration of heavy metal ions in an aqueous waste solution, comprising the steps of:(a) contacting the aqueous waste solution with a mixed culture of Citrobacter freundii and a dissimulatory sulfate reducer, in the presence of nutrient sufficient to satisfy the nutritional requirements of the mixed culture, for a time sufficient to produce sulfide ions from a sulfide-ion precursor in the aqueous waste solution or nutrient and to precipitate the heavy metal ions in the form of corresponding sulfides and(b) removing the thus-precipitated sulfides from the waste solution.
    Type: Grant
    Filed: June 17, 1987
    Date of Patent: December 6, 1988
    Inventors: Nathaniel W. Revis, Tanya R. Osborne, Charles T. Hadden
  • Reduction of trace elements to the elemental form by microorganisms
    Patent number: 4728427
    Abstract: A process for reducing the concentration of ionic species of heavy metals in an aqueous waste solution by conversion to a corresponding elemental metal comprises contacting the waste solution containing ionic species of one or more heavy metals with a culture of Pseudomonas maltophilia ATCC 53510 in the presence of an amount of nutrient medium sufficient to satisfy nutritional requirements of cells of the culture of Pseudomonas maltophilia ATCC 53510. When the ionic species is other than Hg.sup.+ or Hg.sup.++, other species of Pseudomonas can be used.
    Type: Grant
    Filed: April 3, 1987
    Date of Patent: March 1, 1988
    Inventors: Nathaniel W. Revis, Suzanne B. Benson, Tanya R. Osborne, Charles T. Hadden