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US 7,001,583 B2Granted
Essentially insoluble heavy metal sulfide slurry for wastewater treatment
AssigneeSouthern Water Treatment Company, Inc.
InventorGregory S. Bowers
Life of this patent
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AssigneeSouthern Water Treatment Company, Inc.
InventorGregory S. Bowers
Estimating the term…
A product and method for the removal of pollutant heavy metals from aqueous solutions which precludes the end user from storing, handling, feeding and controlling hazardous soluble sulfide materials. The product is a slurry which includes a mixture of a liquid medium and an essentially insoluble salt wherein the salt is the reaction product of heavy metal ions, preferably selected from Mn++ ions, Fe++ ions, and Fe+++ ions, and sulfide ions derived from soluble sulfide sources such as sodium sulfide, hydrogen sulfide, and sodium hydrosulfide. Addition of the subject slurry to a wastewater stream will effect the precipitation of heavy metals with lesser equilibrium sulfide ion concentrations than that of the essentially insoluble salt. Solids collected by this method may be returned to subsequent wastewater streams for additional removal of heavy metals by any excess heavy metal sulfide salt.
A heavy metal sulfide slurry for use in a wastewater treatment process comprising a mixture consisting essentially of a liquid medium and an essentially insoluble salt comprising the reaction product of heavy metal ions and sulfide ions, the essentially insoluble salt having a particle size distribution wherein at least about 50 percent of the particles have a size of less than 1 micron, and the essentially insoluble salt comprising greater than 2 percent by weight of the slurry, wherein upon addition to a wastewater stream containing at least one heavy metal pollutant selected from the group consisting of Zn++, Ni++, Sn++, Co++, Pb++, Cd++, Ag+, Bi++, Cu++, and Hg++, the slurry reacts with and precipitates the heavy metal pollutant.
A heavy metal sulfide slurry for use in a wastewater treatment process made by the method comprising the steps of:
Dependencies are inferred from the claim text.