Method for removing polychlorinated dibenzodioxins and polychlorinated dibenzofurans from paper mill sludge
AssigneeKimberly-Clark Corporation
InventorsShafi U. Hossain, Carol A. Blaney
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Abstract
A process for removing PCDD's and PCDF's from paper mill sludge is provided. The process comprises combining the sludge with an oxidant and then oxidizing the sludge under supercritical or near supercritical conditions to destroy the PCDD's and PCDF's. Using this process, destruction efficiencies of greater than 98% have been achieved for 2,3,7,8-TCDD, which is reportedly the most toxic of the dioxins.
Claims14
A method for oxidizing polychlorinated dibenzo-p-dioxins and/or polychlorinated dibenzofurans in a waste product which contains water and cellulose fibers and which may contain clay and/or fillers comprising steps of:
- (a) combining the water-containing waste product with an oxidant;
- and
- (b) subjecting the combination of the water-containing waste product and the oxidant to supercritical or near supercritical conditions at a temperature in the range of from about 374.degree. C. to about 750.degree. C. for a period of time sufficient to oxidize at least about 90 percent of the polychlorinated dibenzo-p-dioxins and/or polychlorinated dibenzofurans in the waste product.
Dependencies are inferred from the claim text.