Abstract: A method of treating mercury-contaminated material to obtain a treated product having reduced mercury leachability includes the steps of (a) admixing the mercury-contaminated material with a reagent system comprising calcium sulfide (CaS) and trisodium phosphate (TNaP), wherein the calcium sulfide and trisodium phosphate are preferably provided at a CaS:TNaP ratio of from 2:1 to 1:2, on a dry weight reagent basis, and the reagent system is preferably provided in an amount equal to 0.4% to 5% by weight of the contaminated material; and (b) adding water as needed to achieve a moisture content of at least 5% by weight of the contaminated material.

Abstract: A reagent set includes an oxidant, acid, and adsorbent, which is used in a method for reducing the leachability and release of PFAS, mercury, and other contaminants from soils, sediments, and other solid materials or waste when treated materials are exposed to acid rain, snow melt, runoff, landfill leachate, etc. The reagents are mixed with a quantity of contaminated material and water is added as needed in order to reduce the leachability of the contaminants from the treated host material, where the admixture end-product suitably removes contaminants from fluids that contact and/or otherwise permeate and/or pass through and/or around the treated admixture. The reagent set and method of use offer environmental professionals long-term, economically viable waste management solutions for removing contaminants from contamination source areas, spill and manufacturing release sites, impacted media, and landfills, as well as from the fluids that contact reagent-treated material.

Abstract: A reagent system for treating heavy metal-contaminated materials is provided and includes an oxidizer, a soluble phosphate, and an alkaline hydroxide source, such as a caustic soda or lime. A method of treating mine waste bearing one or more heavy metals is also provided and includes the step of admixing a reagent system with heavy metal-containing material to preferentially reduce the leachability of heavy metals and form precipitates and complexes of low metal solubility that remain stable within the host solid matrix for long durations in acidic and abrasive conditions.

Abstract: A reagent system for treating heavy metal-contaminated materials is provided and includes an oxidizer, a soluble phosphate, and an alkaline hydroxide source, such as a caustic soda or lime. A method of treating mine waste bearing one or more heavy metals is also provided and includes the step of admixing a reagent system with heavy metal-containing material to preferentially reduce the leachability of heavy metals and form precipitates and complexes of low metal solubility that remain stable within the host solid matrix for long durations in acidic and abrasive conditions.

Abstract: A reagent system for treating heavy metal-contaminated materials is provided and includes an oxidizer, a soluble phosphate, and an alkaline hydroxide source, such as a caustic soda or lime. A method of treating mine waste bearing one or more heavy metals is also provided and includes the step of admixing a reagent system with heavy metal-containing material to preferentially reduce the leachability of heavy metals and form precipitates and complexes of low metal solubility that remain stable within the host solid matrix for long durations in acidic and abrasive conditions.

Abstract: A method of treating mercury-contaminated material to obtain a treated product having reduced mercury leachability includes the steps of (a) admixing the mercury-contaminated material with a reagent system comprising calcium sulfide (CaS) and trisodium phosphate (TNaP), wherein the calcium sulfide and trisodium phosphate are preferably provided at a CaS:TNaP ratio of from 2:1 to 1:2, on a dry weight reagent basis, and the reagent system is preferably provided in an amount equal to 0.4% to 5% by weight of the contaminated material; and (b) adding water as needed to achieve a moisture content of at least 5% by weight of the contaminated material.