METHOD FOR TREATING SOIL AND GROUNDWATER CONTAINING HEAVY METALS INCLUDING NICKEL

A method of reducing the mobility of metal contaminates in mediums such as soil, groundwater, sludge, etc. that involves contacting the mediums with a reagent that is a ferrous sulfide suspension that contains at least FeS and Al(OH)3. The reagent is produced by reacting a solution that contains at least NaAlO2 and NaOH with a solution that contains FeCl2, HCl and water to form a reaction mixture that contains Fe2+, Cl−, Na+, Al(OH)3 and H2O; and adding NaHS to the reaction mixture. The mobility of the metal contaminates is reduce by adsorption of the metal contaminates in the medium onto the surface of ferrous sulfide or Al(OH)3 in the ferrous sulfide suspension; adsorption of the metal contaminates in the medium onto iron (hydr)-oxides formed in the suspension; and precipitation of the metal contaminates.