摘要:
Described is a process for decontaminating wood treated with preservative such as chromium copper arsenate (CCA) including contacting the contaminated wood with water and inorganic acid at a concentration between 0.05 and 0.8 N at less than 100° C. to leach out the contaminants and then separate the wood from the solution. Also described is a process for extracting metals such as copper from a solution containing chromium, copper and arsenic, such as the leachate solution used to decontaminate CCA-treated wood, by precipitation using a coagulant at a pH favoring precipitation of arsenic and continued solubility of copper, or by ion exchange resins.
摘要:
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.
摘要:
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≦pH≦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 iron of dry sludge; the hydrogen peroxide is used in such an amount as to obtain a concentration ranging between 5 and 40 kg of H2O2 per 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.
摘要:
A process for treating a waste material coming from aluminum production, the waste material containing contaminants polycyclic aromatic hydrocarbons (PAH) and inorganic fluoride compounds containing fluoride ions, involves flotation of a waste mixture of the waste material in the presence of a surfactant capable of producing PAH-rich micelles that are floated to produce froth containing the PAH-rich micelles; and stabilization of the waste mixture by adding a fluoride ion stabilizer to form stabilized fluoride compounds with reduced solubility in the waste mixture and in a toxicity characteristics leaching procedure test, to produce decontaminated solids containing the stabilized fluoride compounds and a leachate solution.
摘要:
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≦pH≦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 H2O2 per 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.
摘要:
The present document describes a process and a bioreactor for reducing a bisphenol compound content of a wastewater using a membrane bioreactor containing a biomass in a volatile suspended solid (VSS) form where the biomass in the membrane bioreactor is operating continuously to reduce bisphenol compound content when the bisphenol compound volumetric load is below 108 g m−3 d−1.