Abstract: A method for treating and disposing of mercury—from mercury-contaminated waste—includes recovering high-purity mercury (e.g., greater than about 99.0 wt. % elemental Hg) from the mercury-contaminated waste. The high-purity mercury is converted to mercuric sulfide (HgS). The mercuric sulfide (HgS) is intermixed with a polymer-based material to form an encapsulated mercury material. The encapsulated mercury material is disposed within a sealed waste container. The sealed waste container is disposed of at a landfill site. Also disclosed is a mercury-including waste product that comprises pellets. The pellets comprise mercuric sulfide within a polymer material.