Institut National De La Recherche Scientifique

Institut National De La Recherche

Corporation Biolix

Tremblay, Richard

Guy Mercier

Sandra Kentish

Jean-Francois Blais

Emmanuelle Cecchi

Jean-François Blais

Sandra Elizabeth Kentish

Sanoopkumar Puthiya Veetil

Louis-Cesar Pasquier

Myriam Chartier

Patrick Drogui

Nassima Kemache

Louis-César Pasquier

Rajeshwar D Tyagi

Danielle Leblanc

Guy Roberge

Christine Sauvageau

Fatima Hammy

Jean-Louis Sasseville

Nathalie Meunier

Geneviève Bélanger

Julia Mouton

Amelie Janin

Marc-Andre Bureau

Jean-françois Blais

A process for producing magnesia can include contacting CO-containing emissions with a magnesium-containing material to produce magnesium carbonate; subjecting the magnesium carbonate to calcination to produce a COby-product and magnesia; and recycling at least a portion of the COby-product for contacting the magnesium-containing material to produce the magnesium carbonate. The magnesium-containing material can include mining residues, such as phyllosilicate or chrysotile mining residue, and the magnesium carbonate produced can include precipitated nesquehonite that is subjected to calcination to produce the magnesia.

Production of low carbon footprint magnesia

A process for producing magnesia can include contacting CO2-containing emissions with a magnesium-containing material to produce magnesium carbonate; subjecting the magnesium carbonate to calcination to produce a CO2 by-product and magnesia; and recycling at least a portion of the COby-product for contacting the magnesium-containing material to produce the magnesium carbonate. The magnesium-containing material can include mining residues, such as phyllosilicate or chrysotile mining residue, and the magnesium carbonate produced can include precipitated nesquehonite that is subjected to calcination to produce the magnesia.

Techniques are described for chemical sequestration of carbon dioxide and production of precipitated magnesium carbonate. The process can include contacting carbon dioxide from industrial emissions with water and magnesium-containing particulate material, such as serpentinite, which is thermally pre-treated and has a particle size of at most 75 microns. The process can also include separation of the loaded aqueous stream from the solids, followed by precipitation of magnesium carbonate material that includes carbon and oxygen from industrial emissions and magnesium from serpentinite or chrysotile mining residue, for example.

Carbon dioxide chemical sequestration from industrial emissions by carbonation

Processes, methods, system and uses in relation to chemical sequestration of carbon dioxide from a carbon dioxide containing gas by carbonation of an alkaline earth metal containing material. The carbon dioxide containing gas is contacted with an aqueous slurry in a carbonation unit for carbonation of at least a portion of the alkaline earth metal to produce a carbon dioxide depleted gas and a carbonate loaded slurry which is substantially exempt of precipitated alkaline earth. metal carbonates. The carbonate loaded slurry is then separated into an aqueous phase and a solid phase; and the aqueous phase is supplied to a precipitation unit for precipitating alkaline earth metal carbonates. The carbonation stage may be performed at a carbonation temperature between about 10&#xb0; C. and about 40&#xb0; C. and a carbonation pressure between about 1 bar and about 20 bars. The solid phase may be recycled to the carbonation stage.

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

The invention concerns a method for stabilizing and conditioning wastewater sludge. The invention is characterized in that it consists in treating sludge in an acid environment (3.0&#x2266;pH&#x2266;5.0), with an inorganic acid and two oxidizing agents, that is a ferric iron salt and hydrogen peroxide. The ferric iron salt is used in such an amount as to obtain a concentration ranging between 5 and 40 kg of Fe per ton of dry sludge; the hydrogen peroxide is used in such an amount as to obtain a concentration ranging between 5 and 40 kg of HOper ton of dry sludge; mixing the treated sludge for a time interval sufficient to stabilize the sludge and improve its dehydrability; then flocculating the stabilized sludge by adding an organic polymer; then dehydrating the flocculated sludge. Said method enables to significantly improve the dehydrability properties of the sludge while increasing the dry solid content during its mechanical dehydration.

Method for stabilizing and conditioning urban and industrial wastewater sludge

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

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.

Hybrid chemical and biological process for decontaminating sludge from municipal sewage

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.

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Guy Mercier