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.
