Abstract: A method for treating a heavy metal-containing liquid, such as a wastewater stream, oil for recycling, or other metal-bearing liquid, with a trithiocarbonate, particularly an alkali metal trithiocarbonate, such as sodium trithiocarbonate, to precipitate the metals as insoluble sulfides. The precipitated metal sulfides are recovered as a low volume sludge, which can be processed through standard metallurgical techniques to yield the metals in economically useful forms. Among the most unexpected results produced by this method is the lowering of the selenium content in a naturally occurring body of water from 1.0 ppm to 0.0015 ppm.

Abstract: A method for removing heavy metals from wastewater streams removes such heavy metal by treating heavy metal-containing wastewater with a water soluble tri-thio carbonate, particularly an alkali metal tri-thio carbonate, such as sodium tri-thio carbonate (Na.sub.2 CS.sub.3) to precipitate heavy metals therefrom.