초록 ▼

A method to remove heavy metals concentrations in water down to very low levels is described. The method calls for the addition of a soluble sulfide to the water. This is followed adding a soluble iron reagent such as ferrous sulfate or ferrous chloride. The water is aerated. As an alternative to ae

A method to remove heavy metals concentrations in water down to very low levels is described. The method calls for the addition of a soluble sulfide to the water. This is followed adding a soluble iron reagent such as ferrous sulfate or ferrous chloride. The water is aerated. As an alternative to aeration, the pH of the water can be increased. Finally, the solids generated from the above steps are separated from the water. This method has been shown to remove heavy metals, particularly copper and zinc, from actual industrial wastewater to very low concentrations, i.e., below about 100 ppb. Furthermore, the treated water is free of sulfide. The byproduct sludge comprises iron sulfide, iron oxides, iron hydroxides, and the heavy metal sulfides.

대표청구항 ▼

[ What is claimed is:] [1.] A method for removal of heavy metals from waste water, comprising:(a) adding an amount of sulfide reagent in a soluble form to the waste water, wherein the quantity of sulfide reagent added is such that the molar ratio of sulfide to metals is between about 50:1 to about 1

[ What is claimed is:] [1.] A method for removal of heavy metals from waste water, comprising:(a) adding an amount of sulfide reagent in a soluble form to the waste water, wherein the quantity of sulfide reagent added is such that the molar ratio of sulfide to metals is between about 50:1 to about 1000:1, and allowing the formation of heavy metal sulfide solids to proceed;(b) adding an amount of an iron reagent in soluble form to the waste water, thereby forming iron sulfide solids, wherein the amount of iron reagent is at least equal to the amount of sulfide added to the waste water;(c) precipitating excess iron ions from solution; and(d) separating the solids from the water.