Method for treatment of hazardous paint residue
OwnerKeith E. Forresterinventor
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Abstract
The invention provides an optimal method for stabilization of heavy metal bearing paint residue subject to acid and water leaching tests or leach conditions by addition of environment safe, worker safe, multi-media compatible, non-separating, non-embedding, stabilizing agent and optional complexing agent(s) to the blast media, thus allowing for pre-blending of stabilizer and blast media and field production of a uniform and steady state stabilizer within media for stabilization outside or within an OSHA containment building or collection device, such that leaching of heavy metals such as lead are inhibited to desired levels. The resultant stabilized paint residue and spent blast media mixture is suitable for on-site reuse, off-site reuse, or disposal as RCRA non-hazardous waste.
Claims16
A method of reducing the solubility of a mixture of heavy metal bearing paint residue and spent paint removal media under leach test conditions, comprising contacting a mixture of heavy metal bearing paint residue and spent paint removal media with at least one heavy metal stabilizing agent of a physical shape, density, and in an amount effective to reduce the solubility of the heavy metal under leach test conditions to a level no more than a hazardous waste lower limit as established under USEPA RCRA regulations 40 CFR part 261.24, as determined in an EPA TCLP test performed on the stabilized material or waste, as set forth in the Federal Register, vol. 55, no. 126, pp. 26985-26998 (Jun. 29, 1990), wherein the at least one heavy metal stabilizing agent resists phase-separation or sifting-separation from paint removal media in a pre-mixed storage device and/or pressurized media and stabilizer pre-blend pot prior to nozzle discharge, and further wherein the at least one heavy metal stabilizing agent resists embedding onto the media blasted substrate as seen by the human naked eye.
A method of reducing the solubility of a mixture comprising heavy metal bearing paint residue and spent paint removal media under leach test conditions, the method comprising contacting the mixture comprising paint residue and spent paint removal media with a combination of at least one heavy metal stabilizing agent and at least one complexing agent, wherein the at least one heavy metal stabilizing agent is of a physical shape, density, and in an amount effective in reducing the solubility of heavy metal under leach test conditions to a level no more than hazardous waste lower limit as established under USEPA RCRA regulations 40 CFR part 261.24, as determined in an EPA TCLP test performed on the stabilized material or waste, as set forth in the Federal Register, vol. 55, no. 126, pp. 26985-26998 (Jun. 29, 1990), wherein the at least one heavy metal stabilizing agent resists phase-separation or sifting-separation from blast media in a pre-mixed storage device and/or pressurized media and stabilizer pre-blend pot prior to nozzle discharge, and further wherein the stabilizer agent resists embedding onto a media blasted substrate as seen by the human naked eye;
- wherein the at least one complexing agent is selected to allow for formation of low toxicity and low solubility solid phase mineral, from the paint residue and removal media mixture available heavy metals and introduced stabilizers and removal media matrix, such as Lead Phosphate, Lead Chloropyromorphite, Lead Corkite, Lead Plumbogummite, Lead Sulfide, Lead Carbonate, Ferric Arsenate, and Trivalent Chromium Hydroxide.
Dependencies are inferred from the claim text.