The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 24, 1996
Filed:
Apr. 21, 1995
Michael V Rowley, Vancouver, B.C., V5Z 2S9, CA;
Douglas D Warkentin, Vancouver, B.C., V5Z 2S9, CA;
Beverly M Piroshco, Vancouver, B.C., V6S 1M1, CA;
Other;
Abstract
In accordance with the process of the invention, bacteria are used to provide hydrogen sulfide and carbonate compounds for treating solutions containing metal ions. To produce the hydrogen sulfide, the bacteria utilize sulfate ions present in the solution. Hydrogen sulfide produced by the bacteria is used to remove metals from the solution as insoluble metal sulfides. The process of the invention thereby removes sulfate and metal ions from the treated solution. The bacteria used are mixed populations, including strains of naturally-occurring sulfate reducing bacteria, which have been serially adapted and selected to be highly active with the particular solutions to be treated and with the carbon and hydrogen sources being utilized. The bacteria may be fed gaseous hydrogen and carbon nutrients produced by a partial oxidation burner. Carbonate compounds produced by the bacteria may be used to raise the solution pH for treatment and discharge. By controlling the addition of hydrogen sulfide and carbonate compounds to the solution, the preferential isolation of particular metal sulfide concentrates may be accomplished in separate precipitation steps, each with a specific pH and sulfide dosage.