Patents by Inventor Earl R. Markham

Earl R. Markham 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).

  • Organic base fertilizer from municipal sewage sludge
    Patent number: 5252116
    Abstract: A process for the production of a granular fertilizer product from biological or municipal sewage sludge is described. This process involves (1) gently blending the biological sludge with sufficient lime-containing material (preferably lime kiln dust) to raise the pH of the blended material to at least 11 pH units, and preferably at least 12 pH units, in such a manner as to avoid or prevent the formation of a slurry; (2) then conditioning the blended materials at a temperature of 180.degree. F.
    Type: Grant
    Filed: September 3, 1991
    Date of Patent: October 12, 1993
    Assignee: TRG International Waste Management, Ltd.
    Inventors: Earl R. Markham, John T. Markham, Edward G. Markham