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:
Feb. 15, 2005
Filed:
Feb. 01, 2002
Jean-francois Blais, Beauport, CA;
Nathalie Meunier, Beauport, CA;
Jean-louis Sasseville, Cap-Rouge, CA;
Rajeshwar D. Tyagi, Sainte-Foy, CA;
Guy Mercier, Quebec, CA;
Fatima Hammy, Casablanca, MA;
Jean-Francois Blais, Beauport, CA;
Nathalie Meunier, Beauport, CA;
Jean-Louis Sasseville, Cap-Rouge, CA;
Rajeshwar D. Tyagi, Sainte-Foy, CA;
Guy Mercier, Quebec, CA;
Fatima Hammy, Casablanca, MA;
Institut National de la Recherche, Quebec, CA;
Abstract
The invention relates to a hybrid biological and chemical method for decontaminating sludge containing heavy metals and pathogenic microorganisms, consisting of the following steps: the sludge is mixed with an acidic leaching solution in order to acidify the sludge with a pH which is low enough to solubilize the majority of the heavy metals and to destroy most of the pathogenic microorganisms but which is also high enough to minimize the solubilization of fertilizing elements; oxidation-reduction of more than +400 mv is maintained, liquid-solid separation occurs in order to obtain a solid fraction comprising decontaminated acidic sludge and a liquid fraction comprising heavy metals which are dissolved in a leaching solution; the sludge is neutralized: and neturalized decontaminated sludge is recovered, whereby the fertilizing elements contained therein, i.e. carbon, nitrogen and phosphorus, remain substantially unchanged in relation to the initially contaminated sludge.