Stabilization of mercury in mercury-containing materials

A process for stabilizing in situ soluble mercury in landfill deposits having mercury-containing materials which comprises:

• (a) applying to said deposits a stabilizing amount of an inorganic sulfur compound selected from the group consisting of potassium sulfide, alkaline earth metal sulfides, sulfides of transition elements number 25-30, aluminum sulfides, cadmium sulfides, antimony sulfides, Group IV sulfides, alkali metal thiosulfates, alkaline earth metal thiosulfates, iron thiosulfates, alkali metal dithionites and mixtures thereof;
• (b) applying an aqueous solution to said deposits to disperse said inorganic sulfur compound into said deposits, said inorganic sulfur compound reacting with said soluble mercury to form an insoluble mercury compound in said deposits, a portion of said solution leaving said deposits as an effluent;
• (c) recovering said effluent from said deposits;
• and
• (d) recycling said effluent to step (b).