Abstract: A leaching-stabilized heavy metal-contaminated matrix can be stored in a subsurface saturated zone by contacting the matrix with an amount of an agent for increasing acid-neutralization capacity sufficient to provide the stored matrix a preselected permanence level.

Abstract: This invention provides a method for chemical stabilization of combined Pb and As bearing materials, contaminated soils and wastes subject to acid and water leaching tests or leach conditions by addition of stabilizing agents such that the leaching potential is inhibited to desired levels. The resultant material or waste after stabilization is deemed suitable for on-site reuse, off-site reuse or disposal as RCRA non-hazardous waste.

Abstract: A method for solidifying an oil-contaminated aqueous waste in situ or ex situ includes the step of combining the oil-contaminated waste with a clay, a cement and a sulfite salt solidification agent to form a solidified waste matrix, wherein the solidification agent undergoes hydration and cementation reactions in the waste matrix in the presence of water. Optionally, heavy metal stabilizing agents can also be combined with the waste.

Abstract: Process for the treatment of a sludge containing heavy metals and organic matter according to which foaming of the sludge is brought about and it is dried.

Abstract: The present invention relates to a method for direct treatment of liquid wastes containing up to 10% or 100,000 mg/L of arsenic by solidification/stabilization in a relatively cost effective and environmentally safe. The method also permits the simultaneous utilization other heavy metal bearing wastes (such as spent catalysts), in the solidification/stabilization of liquid wastes containing very high concentration of arsenic. It also deals with a method for converting liquid wastes containing very high concentration of arsenic into a non-leachable solid residue ready for final disposal. The direct treatment of liquid wastes containing very high concentration of arsenic by solidification/stabilization will eliminate the additional stage of converting liquid wastes to solid or semi-solid form prior to solidification/stabilization, thereby significant reduction in overall cost associated with arsenic waste treatment.

Abstract: This invention provides a method for stabilization of hexavalent chromium and trivalent chromium bearing wastes, materials, and contaminated soils subject to acid and water leaching tests or leach conditions by addition of water solution, hexavalent chromium reducing agent, precipitating and pH increase agent, and chromium reversion control and stabilizing agents such that leaching of chromium is inhibited to desired levels and resists reversion to hexavalent chromium form over time. The resultant material, contaminated soil and/or waste after stabilization and reversion control is deemed suitable for on-site reuse, off-site reuse or disposal as RCRA non-hazardous waste.

Abstract: This invention provides a method for stabilization and treatment of heavy metal bearing materials and wastes subject to acid leaching tests or leach conditions and odor limits by addition of acid semi-soluble DiCalcium Phosphate DiHydrate such that the leaching potential is inhibited to desired levels and odors are reduced to desired levels and the material or waste is free flowing, more permeable, less weight and permits immediate handling and disposal or reuse. The resultant material or waste after stabilization is deemed suitable for on-site reuse, off-site reuse or disposal as RCRA non-hazardous waste.

Abstract: This invention provides a method for stabilization of heavy metal bearing materials and wastes subject to acid leaching tests or leach conditions by addition of acid semi-soluble DiCalcium Phosphate DiHydrate such that the leaching potential is inhibited to desired levels and the material or waste is free flowing, more permeable, less weight and permits immediate handling and disposal or reuse. The resultant material or waste after stabilization is deemed suitable for on-site reuse, off-site reuse or disposal as RCRA non-hazardous waste.

Abstract: The present invention provides a method for treating dredged material in which liquid is first added to the dredged material, and dewatering the dredged material to obtain a filtrate and a solid portion. Contaminants are removed from the dredged material by at least one oxidation process. The solid portion may be used to form structural articles.

Abstract: Method of inerting mineral residues comprising automobile grinding residues, in which method water is added to the mineral residues so as to form a paste, the paste is mixed with phosphoric acid, and the resulting mixture is calcined.

Abstract: A method of using high temperature plasma to disintegrate waste containing titanyl phthalocyanine (TiOPc) comprises heating a mixture of titanyl phthalocyanine (TiOPc), a vitrifying material and optionally selected waste soil to a temperature of 1,220° C. to 10,000° C. until the mixture becomes a molten lava. The plasma breaks down the titanyl phthalocyanine and encapsulates the benign products in the lava that is chemically very stable. Since the titanyl phthalocyanine (TiOPc) is disintegrated completely in the process, the titanyl phtbalocyanine (TiOPc) no longer represents a threat to the environmental.

Abstract: A process for producing building materials, such as asphalt, cement, concrete, mortar, or plaster board from liquid paint sludge containing water and paint solids produced from overspray in commercial paint booth operations. The preferred embodiment comprises adding the liquid paint sludge as the hydrating agent directly to the building material mix.

Abstract: This invention provides a method for stabilization of lead smelter slag and matte subject to acid and water leaching tests or leach conditions by addition of stabilizing agents into the smelter feed such that leaching of lead is inhibited to desired levels. The resultant waste after stabilization is deemed suitable for on-site reuse, off-site reuse or disposal as RCRA non-hazardous waste.

Abstract: A method of collecting, treating, transporting and disposing of hazardous debris which combines the standards of macroencapsulation and microencapsulation and involves the use of a liner to contain hazardous debris together with reagents that reduce leachability of a constituent of the hazardous debris. The liner is supported in a rolloff box or other transportable container on site where the hazardous debris is collected. Prior to placing hazardous debris into the liner, a layer of reagent(s) is provided in the bottom of the liner. Once hazardous debris is loaded in the liner, addition free flowing reagent(s) is/are added to fill void space in and around the hazardous debris, after which the top of the liner is sealed for disposal in a landfill.

Abstract: A method for removing metal contaminants from acidic mine wastewater using lignin derivatives, such as lignosulfonates and kraft lignin, an alkali coagulant, such as a lime compound, and an alkaline composition for increasing the pH. The lignin derivatives are dispersed in the wastewater and the coagulant is added, increasing the pH to about 4.5–8.5 and causing the formation of a floc. The alkaline composition is then added to bring the pH to about 9 to 10, causing the further formation of a floc. Optionally, air oxidation is carried out, reducing the pH to about 8.1–8.6. Optionally, a ferric or ferrous salt may also be added. The flocs comprise metal-lignin colloids, metal hydroxides and metal salts. The flocs coagulate to form a sludge. Optionally, fly ash or diatomaceous earth may be added to increase the density and stability of the sludge. The sludge that is formed contains the metals and is separated from the treated water by filtration.

Abstract: A method for removing metal contaminants from water uses lignin derivatives, such as lignosulfonates and kraft lignin, a coagulant, such as a metal salt, and a pH-increasing composition. The lignin derivative is dispersed in the contaminated water, the coagulant is added and the pH is adjusted as required to cause flocculation. A sludge is formed that contains the metals and that is separated from the treated water by filtration. Related methods are used to reduce the leachable metal content of contaminated soils. The invention also provides a composition for stabilizing the metal contaminants in soil, comprising lignin derivatives, a coagulant and a composition for increasing the pH. The mixture is blended with the contaminated soil, reducing its leachable metal content.

Abstract: A method for treating (in situ) large bodies of water contaminated with heavy metals and having varying density stratas to immobilize the contaminant metals is disclosed. The method, or process for (in situ) immobilization of metals is focused on treating large bodies of water having metals therein that are also adjacent a border of soil or earthen materials in an attempt to immobilize the metals from penetrating through the soil. The method is also able to treat the soil water boundary within the pit lake to provide additional immobilization. The pit lakes can include open pit lakes, subterranean mine lakes, flowing streams and the like. The method is also able to treat an abandoned mine prior to the filling of the mine with water. Initially, the density mean of the body of water is determined, which is densest typical at regions at or approaching 4 degrees C.

Abstract: A process for the stabilization of metal bearing waste is provided that is based upon the discovery that landfills have anaerobic environments. This process includes adjusting the pH of the waste and adding a sulfide containing reducing agent to the waste to achieve a reducing environment. In one embodiment, electric arc furnace dust is stabilized for landfill disposal. Also provided is a method for a determination of landfilled waste leachability. This method is performed under conditions that simulate the chemical characteristics of landfills. In one embodiment, stabilized metal bearing waste is deoxygenated and a simulated leachate is prepared under anaerobic conditions.

Abstract: A reactive coating composition and method for treating a surface including heavy metals by applying the reactive coating composition to the surface. The surface can be, for example, a paint layer containing heavy metals. The reactive coating composition includes a stabilizing agent to stabilize the heavy metal and a permeability enhancing agent to increase the permeability of the paint layer, facilitating the reaction of the heavy metal with the stabilizing agent. The structure including the treated paint layer can be left in place or can be disposed in a non-hazardous landfill.

Abstract: Process for rendering inert a sludge (1) comprising heavy metals and organic matter, according to which phosphoric acid (2) is added to the sludge and the latter is subjected to calcination (6). A hydraulic binder (9) is mixed with the product of the calcination (7) and mixed with water (8). The resulting mixture (11) is subjected to setting and curing.

Abstract: A process for disposing of solvent-containing liquids so that they do not contaminate ground water. An absorbent blend is mixed into a water-containing solvent mixture at the rate of about 1 lb. of blend per gallon of liquid. The blend is made up of a swellable polymer, consisting of polyacrylamide/polyacrylate co-polymer salt or poly 2-propenamide-co-2-propenoic acid homopolymer salt which swells and absorbs liquid. The blend also contains a mixture of solid absorbents. The resulting mixture is stirred in the container until it becomes thick and then it is allowed to set to provide a disposable modeling clay-like solid. The resulting solid material, after curing, may be then simply added to solid trash, and thus, be freed from contaminating ground water.

Abstract: The invention relates to a mixture and a process for the treatment of waste materials and the use of the mixture for the treatment of waste materials and waste material treated therewith. The mixture comprises (A) at least one zinc salt of a saturated or unsaturated aliphatic or aromatic carboxylic acid, (B) at least one calcium salt of a saturated or unsaturated aliphatic or aromatic carboxylic acid, (C) at least one hydrophobing agent, (D) at least one amino alcohol and (E) NH3.

Abstract: A remediation system comprises a primary scalping screen, a primary pump and sump, a large diameter maximum density separator with flocculant injection ring, a secondary pump and sump, a small diameter maximum density separator with flocculant injection ring, a static sieve screen, a flocculation sump, a vibrating screen, a dewatering device, a tertiary sump and pump, a secondary flocculation tank, and a pugmill. Screens move water and particulates through the components. In this manner larger particles are separated from smaller particles and the particles are further dewatered.

Abstract: In a method for reducing the leaching of oxyanion forming elements, in particular chromium, from materials containing environmentally noxious constituents, especially from incineration residues, especially flue gas cleaning products from waste incineration, in particular fly ash, the said materials are admixed with an aqueous medium such as water in a closed container in a liquid-solid ratio sufficient to cause reducing conditions capable of stabilizing oxyanion forming elements, in particular chromium, due to oxidation of metallic Al, Zn, Fe, and other free metals present in the said materials.

Abstract: A method is provided for stabilizing toxic materials in a waste matrix and in the pore water of the waste matrix. The method includes the steps of combining with the waste matrix (and pore water) an agent for controlling the oxidation-reduction potential of the matrix/water, an agent for controlling the pH of matrix/water, and an agent for adsorbing or coprecipitating the toxic material in the matrix/water.

Abstract: A method for removing at least one of chromate and other oxy-metal ions from liquid solutions includes contacting the liquid solution with solid barium compounds as adsorbents so that the at least one of chromate and other oxy-metal ions in liquid solution are subject to an exchange reaction with the anion of solid barium compounds to produce products including at least one of solid barium chromate and oxy-metal barium compounds and are removed from the liquid solution by a liquid-solid separation operation. A method for stabilizing at least one of chromate and other oxy-metal ions that are present in liquid or sludge wastes includes mixing the liquid or sludge wastes with barium compounds in solid form, so that the at least one of chromate and oxy-metal ions are immobilized in a solidified body after curing of the mixture.

Abstract: A method for recombining and then solidifying groups of soil particles by utilizing changes in the status and properties of soil particles which comprises a combination (in an adhering state) between soil particles and groups polymers (humin) in an aqueous solution (solvent). By using specified solvents, the preliminary treatment of separating soil particles and polymers is initiated. Secondarily, each structure of groups of soil particles is observed microscopically as a metal complex, and the combining method is accomplished by utilizing substitution based on various reactions (i.e. SN, SE, and SEAr type reactions) along with electron transfer in a solvent made of specified solutes. The substitution includes the rock forming function through the substitution of the hydrogen atom within the hydroxyl group of clay minerals as molecular components and the dehydration and dissociation function resulted from the binding structure of oxygen molecule O−2 and Al+3 as components of aluminum oxide.

Abstract: The invention relates to a mixture and a process for the treatment of waste materials and the use of the mixture for the treatment of waste materials and waste material treated therewith. The mixture comprises (A) at least one zinc salt of a saturated or unsaturated aliphatic or aromatic carboxylic acid, (B) at least one calcium salt of a saturated or unsaturated aliphatic or aromatic carboxylic acid, (C) at least one hydrophobing agent, (D) at least on amino alcohol and (E) NH3.

Abstract: A dry pulverulent ash composition is described which comprises a dry pulverulent fly ash to be used as a portland cement substitute for improving the physical properties of a finished concrete product. The ash composition includes fly ash together with an oxidizer present in a dry pulverulent form that is unreacted with the ash and is maintained in an unreacted state during shipment and storage but is capable of reacting with the fly ash upon an addition of water to convert virtually all and preferably over 95% of the sulfur compounds present in the ash to the sulfite form. The oxidizer is present in minor amount from about 0.5% to about 10% by weight of the composition. An aggregate comprising pellets can also be added to the composition together with a minor amount of portland cement and a conditioner e.g., accelerator to form a concrete block product that is up to 10% lighter than a standard concrete block that does not use the present composition and at the same time exhibits improved crushing strength.

Abstract: A new method for combining magnesium oxide, MgO, and magnesium dihydrogen phosphate to form an inexpensive compactible ceramic to stabilize very low solubility metal oxides, ashes, swarfs, and other iron or metal-based additives, to create products and waste forms which can be poured or dye cast, and to reinforce and strengthen the ceramics formed by the addition of fibers to the initial ceramic mixture.

Abstract: A cost-effective, long-term, permanent method for stabilizing chromium in a chromium-contaminated waste matrix characterized by high concentrations of alkaline material (such as lime) includes the steps of contacting a source of hexavalent chromium with a source of ferrous ions to produce ferric ions; oxidizing iron pyrite to produce ferrous sulfate and sulfuric acid; and contacting the alkaline chromium-contaminated particulate matter with the ferrous sulfate and the sulfuric acid for a time sufficient to convert ferrous sulfate into ferric sulfate and to reduce mobile hexavalent chromium to non-leachable trivalent chromium. The method is integrated in that ferrous sulfate produced by oxidizing iron pyrite serves as a source of ferrous ions in the first contacting step. Optionally, ferric ions can be generated in a side reactor and then used to produce ferrous ions. The ferrous ions can be used both to produce further ferric ions in the side reactor and to treat COPR waste.

Abstract: A reactive coating composition and method for treating a surface including heavy metals by applying the reactive coating composition to the surface. The surface can be, for example, a paint layer containing heavy metals. The reactive coating composition includes a stabilizing agent to stabilize the heavy metal and a permeability enhancing agent to increase the permeability of the paint layer, facilitating the reaction of the heavy metal with the stabilizing agent. The structure including the treated paint layer can be left in place or can be disposed in a non-hazardous landfill.

Abstract: The invention pertains to a method for reducing the leaching of heavy metals from air, water and wastewater particulate emissions. The method includes contacting the heavy metal particulate with a complexing agent which converts the molecular form of the particulate to a less soluble and less bioavailable form prior to collection and release to the environment. This method eliminates the need to remove or treat soils and environments exposed to particulate deposition and greatly reduces the environmental and health risks associated with the deposition of heavy metal particulate in the open environment as well as at controlled discharge areas.

Abstract: A method of disposing of photographic silver halide processing solutions including developer, bleach and at least one silver bearing solution comprising a) combining the developer and bleach solutions to oxidize the developing agent in the developer and form a developer/bleach waste solution, b) treating the silver bearing solution(s) to reduce the silver ion level and form a low silver waste solution; and c) contacting the developer/bleach waste solution and the low silver waste solution with an absorbent material to form an apparently dry waste material having a leachable silver ion level below 5 ppm.

Abstract: A process for the treatment of an aqueous coal slurry obtained as tailings from a coal treatment plant and containing fine mineral particles comprises adding to the slurry at least 0.2% of a binder and an amount of dispersant effective to reduce the viscosity and facilitate settling of solids, the % being based on the combined weight of water and mineral solids and allowing the solids to settle. The binder is preferably a cementitious material such as a finely divided blast furnace slag and an activator for the binder such a hydrated lime or Portland cement is preferably also included. The dispersant may be a polyarcylate, polycarboxylate or lignosulphonate.

Abstract: The invention pertains to a method for reducing the leaching of heavy metal from heavy metal the surface of a heavy metal bearing material or waste. The method includes contacting the heavy metal bearing material or waste with a wet process phosphoric acid, optional complexing source and optional surfactant.

Abstract: A porous sintered body in which the leaching amounts of heavy metals are small and having high availability contains 0.5-15 weight % of B2O3, preferably contains 20-60 weight % of Al2O3, 18-60 weight % of SiO2, 1-12 weight % of the sum of Na2O, K2O, Li2O, and P2O5, 1-30 weight % of the sum of CaO, SrO, BaO, and MgO, and 0.5-15 weight % of B2O3.

Abstract: The present invention describes an improved method for forming fly ash slurry by mixing fly ash and water with an additive containing 0.5-2 wt % ammonium salt of humic acid and 0.03 to 0.05 wt % tannin extract. The product slurry does not require large amount of water for transport to storage space due to its enhanced viscosity and stability.

Abstract: This invention provides a method for chemical stabilization of combined heavy metal bearing materials and wastes subject to acid and water leaching tests or leach conditions by addition of stabilizing agents such that the leaching potential is inhibited to desired levels. The resultant material or waste after stabilization is deemed suitable for on-site reuse, off-site reuse or disposal as RCRA non-hazardous waste.

Abstract: A method for reducing the leaching of lead from a lead projectile impact area acting to collect or stop such projectiles includes contacting the lead projectile impact area with a seed of dry granular lead stabilizing agents. This seeding or coating of lead stabilizing agents stabilizes lead in the bullet/shot impact area while also allowing for future lead bullets, fragments or lead shot fired into the soil to be stabilized upon contact with the lead stabilizing agent seeds or contact with rainwater leaching through the lead stabilizing agent seeds produced from the projectile coating, or excess seed from the lead shell projectiles. This method eliminates the need to remove or re-treat range soils and greatly reduces the environmental and health risks associated with the use of lead as projectiles in the open environment as well as at control trap ranges.

Abstract: This invention provides a method for chemical stabilization of heavy metal bearing materials and wastes while minimizing fluoride solubility subject to acid and water leaching tests or leach conditions by addition of stabilizing agents such that the leaching potential is inhibited to desired levels. The resultant material or waste after stabilization is deemed suitable for on-site reuse, off-site reuse or disposal as non-hazardous waste.

Abstract: A supplemental agent for a hazardous waste composition containing electric arc furnace dust (EAFD) includes potassium magnesium sulfate or a magnesium salt such as magnesium sulfate or magnesium chloride. The supplemental agent when mixed with EAFD and water, along with either lime inherent within the EAFD or added lime, reduces the leaching of heavy metals from the waste composition over a wide range of leaching conditions, including both acidic, neutral, and alkaline environments. The method for reducing the concentration of heavy metals in a leachate from the EAFD involves forming a mixture of EAFD, water, the supplemental agent, and, optionally, ferrous sulfate, along with lime, then permitting the mixture to react.

Abstract: The invention pertains to a method for reducing the leaching of heavy metals from air, water and wastewater particulate emissions. The method includes contacting the heavy metal particulate with a complexing agent which converts the molecular form of the particulate to a less soluble and less bioavailable form prior to release to the environment. This method eliminates the need to remove or treat soils and environments exposed to particulate deposition and greatly reduces the environmental and health risks associated with the deposition of heavy metal particulate in the open environment as well as at controlled discharge areas.

Abstract: (A) Heavy metal-containing wastes are kneaded in melt with (B) an alkali metal compound or an alkaline earth metal compound and (C) sulfur, or with (E) a sulfide, or with these along with (D) a salt of a metal of which the standard electrode potential is higher than that of the cation of the component (B) or (E), in the presence of a non-aqueous medium, and the resulting melt mixture is cooled and solidified. In the method of treating heavy metal-containing wastes, the heavy metals in the wastes are efficiently passivated, and the heavy metals thus passivated are not released from the treated wastes.

Abstract: A process for chemical fixation of radionuclides and radioactive compounds present in soils, solid materials, sludges and liquids. Radionuclides and other radioactive compounds are converted to low-temperature Apatite-Group structural isomorphs (general composition: (AB)5(XO4)3Z), usually phosphatic, that are insoluble, non-leachable, non-zeolitic, and pH stable by contacting with a suspension containing a sulfate, hydroxide, chloride, fluoride and/or silicate source and a phosphate anion. The Apatitic-structure end product is chemically altered from the initial material and reduced in volume and mass. The end product can be void of free liquids and exhibits sufficiently high levels of thermal stability to be effective in the presence of heat generating nuclear reactions. The process occurs at ambient temperature and pressure.

Abstract: A method is taught for converting metal contaminants in the soil to less toxic forms as well as permitting their removal from groundwater. A first reactive solution comprising ferrous sulfate and an acid selected from the group consisting of sulfuric acid and phosphoric acid is injected to decomplex contaminants and precipitate them as insoluble compounds. A second reactive solution comprising hydrogen peroxide, and an acid selected from the group consisting of sulfuric acid and phosphoric acid is then injected to destroy organic liquids and enhance decomplexation. The pH of the first solution may range from 3 to 5, and the pH of the second solution range from 3 to 7, preferably 5 to 7. The process is particularly effective where chromium compounds such as hexavalent chromium are the contaminants.

Abstract: A process for vitrifying waste material containing environmentally hazardous metals or metal compounds includes drying a waste material using a flash dryer, where the drying is carried out at a temperature low enough to prevent volatilization of hazardous metals and metal compounds contained in the waste material. Preferably, more than about 95% of the water is removed form the waste material. The dried waste material is transferred from the flash dryer into a melting vessel, melted, collected and cooled to form a vitrified mass of waste material. Gases produced during the process of the invention are filtered, treated, and released into the atmosphere.

Abstract: A method is provided for stabilizing toxic materials in a waste matrix and in the pore water of the waste matrix. The method includes the steps of combining with the waste matrix (and pore water) an agent for controlling the oxidation-reduction potential of the matrix/water, an agent for controlling the pH of matrix/water, and an agent for adsorbing or coprecipitating the toxic material in the matrix/water.

Abstract: A method for stabilizing chromium in a chromium-contaminated waste matrix characterized by high concentrations of alkaline material (such as lime) includes the steps of contacting a source of hexavalent chromium with a source of ferrous ions to produce ferric ions; oxidizing iron pyrite to produce ferrous sulfate and sulfuric acid; and contacting the alkaline chromium-contaminated particulate matter with the ferrous sulfate and the sulfuric acid for a time sufficient to convert ferrous sulfate into ferric sulfate and to reduce mobile hexavalent chromium to non-leachable trivalent chromium. The method is integrated in that ferrous sulfate produced by oxidizing iron pyrite serves as a source of ferrous ions in the first contacting step.

Abstract: A detoxifying agent for use in disposal of noxious wastes that is conducted by solidifying them with cement, consisting essentially of an aqueous solution which comprises as main components (a) small-sized metal cations whose 6-coordination ionic radii are less than 100 pm, (b) medium-sized metal cations whose 6-coordination ionic radii are between 100 pm and 140 pm, and (c) large-sized metal cations whose 6-coordination ionic radii are in excess of 140 pm. This detoxifying agent can provide cement-solidified materials having high strength, substantially free from exudation of toxic substances such as heavy metals, PCBs and dioxins.