Institut National De La Recherche Scientifique

Myriam Chartier

Guy Mercier

Jean-Francois Blais

Jean-François Blais

Patrick Drogui

Christine Sauvageau

Guy Roberge

Geneviève Bélanger

Julia Mouton

Danielle Leblanc

A process for decontaminating a medium polluted with metals and hydrophobic organic compounds (HOC) includes providing an acidic slurry of water, acid, chloride salt, surfactant, and the polluted medium. Flotation is preformed on the acidic slurry to form a HOC-rich froth and an HOC-depleted slurry and the froth is recovered. The slurry is separated to obtain a treated solid and a liquid effluent rich in metallic ions. Preferably, the process also includes recuperating the metals by chemical precipitation and/or electrodeposition to produce a treated solution. Also provided are a decontaminant having an acid, a chloride salt, and a surfactant as well as a chemical kit for decontaminating the polluted medium including the decontaminant in which the acid, chloride salt and surfactant can be mixed with polluted medium in the presence of water before removing at least a portion of the metals and HOC from the polluted medium.

Process, decontaminant and chemical kit for the decontaminating media polluted with metals and hydrophobic organic compounds

A method of treating animal manure yielding a final liquid fraction and solid fractions whereby the final liquid fraction has a suspended solids (SS) content of about 3 g/L or lower comprising subjecting at least a part of said manure to a first biological passive flotation step in a flotation unit having a hydraulic residency time (HRT) of about 4 to about 24 hours with a polymer to yield a first flotation solid fraction and a first flotation liquid fraction, said method comprising a further treatment. An apparatus for treating animal manure comprising a main flotation unit having a HRT of about 4 to about 24 hours, said main flotation units including skimming means for removing floating solids from at least a portion of the surface of the manure and dredging means for removing settled contaminants from at least a portion of the bottom of the tank, whereby at least a part of said manure is directed to the main flotation unit wherein it is separated in a first floating solids fraction, a second liquid fraction and a first settled solids fraction and wherein the second liquid fraction has a SS content of about 3 g/L or lower.

Methods and apparatus for treating animal manure

A method for the treatment of air pollution control (APC) residues comprising the steps of washing the residues at least one time in an alkaline solution maintained at a pH not lower than about 11.5, separating the alkaline washed residues from the alkaline solution. The present method further comprises an optional step of verifying whether the alkaline washed residues are substantially devoid of metal components. When the alkaline washed residues are not substantially devoid of metal components, the alkaline washed residues are washed at least one time in an acid solution maintained at a pH between about 2 and about 4.5 and the acid washed residues are separated from the acid solution so as to produce residues substantially devoid of metal components. The APC residues obtained in application of the methods according to the present invention constitute non-hazardous material/waste.

Method for removing metals from air pollution control residues

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Myriam Chartier