Abstract: A process for treating acidic mine drainage water to remove heavy metal ions is described in which acidic mine drainage water is contacted with direct process residue gel.

Abstract: Wastewater treatment systems, methods and apparatus for polishing a wastewater stream comprising a plurality of contaminants are provided. One system includes a vessel containing a plurality of natural media filtration agents selected to remove selected ones of the plurality of contaminants from the wastewater stream. In one embodiment, the vessel includes a bed of bauxite residue and at least one other natural media filtration agent. In another embodiment, the vessel includes a bed of compost and at least one other natural media filtration agent. The vessel includes a wastewater inlet that is in fluid communication with one or more of the natural media filtration agents. The vessel includes a wastewater outlet that is in fluid communication with one or more of the natural media filtration agents.

Abstract: An iron composition having a plurality of elemental components is disclosed. The major component is an iron component of at least about 68% to about 92% iron by weight. Other components by weight include manganese; cerium; carbon; phosphorous; sulfur; aluminum; silicon; chromium; copper; and zinc. Combined with layers of sand, brick chips and/or charcoal, the iron composition can be used to create a water filter for filtering inorganic arsenic species and soluble metal ions out of water. To enhance hydrous ferric oxide complexation and precipitation, the iron composition may be treated with food grade acids or a water mixture.

Abstract: A sulfurous acid/alkalinization pre-treatment method for wastewaters to condition and remove a number of chemicals/pharmaceuticals and heavy metals before the recovered treated influent undergoes further biological reduction via anaerobic and aerobic digestion.

Abstract: A method for removing a metal from a metal-containing solution comprising contacting the metal-containing solution with a metal-removing composition comprising a substrate, an organic ion, and a metal binding agent, and recovering a solution having a lowered metal concentration when compared to the metal-containing solution.

Abstract: The invention includes ion exchange resins, methods of making ion exchange resins and their use in the removal of perchlorate from water. In one embodiment, the invention comprises a method for removing perchlorate from a water source by contacting the water with an ion exchange resin, wherein the ion exchange resin comprises particles of a crosslinked copolymer comprising: an interpenetrating polymer network (IPN) of at least two polymer components each having a styrenic content greater than 50 molar percent, and a quaternary ammonium functionality.

Abstract: Methods to reduce hexavalent chromium (Cr(VI)) in chromite processing wastes include one or more of the following steps: contacting the chromite processing wastes with an oxygen scavenger or chemical reducer; permitting the chromite processing wastes to react with the oxygen scavenger or chemical reducer; contacting the chromite processing wastes with ferrous ion; contacting the chromite processing wastes with sulfide ion; and, contacting the chromite processing wastes with ferrous sulfide.

Abstract: The invention includes ion exchange resins and their use in the removal of chromium from water. In one embodiment, the invention comprises a method for removing chromium from a water source by contacting the water with an ion exchange resin, wherein the ion exchange resin comprises particles of a crosslinked copolymer comprising: an interpenetrating polymer network (IPN) of at least two polymer components each having a styrenic content greater than 50 molar percent, and a quaternary ammonium functionality.

Abstract: Systems and associated methods for treating contaminant-containing wastewater are provided. The systems generally include a reducing zone for reducing the oxidation-reduction potential of the water and a clean-up zone comprising zero valent iron for removing at least a portion of the contaminant from the contaminant-containing water. The systems are operable to remove one or more contaminants from the contaminant-containing water and are operable for extended durations without clogging due to the formation of iron hydroxides.

Abstract: Compositions and methods and for contaminants from water are provided. The compositions comprise ferric hydroxide and ferric oxyhydride coated substrates for use in removing the contaminant from the water. Contacting water bearing the contaminant with the substrates can substantially reduce contaminant levels therein. Methods of oxidizing the contaminants in water to facilitate their removal by the ferric hydroxide and ferric oxyhydride coated substrates are also provided. The contaminants include, but are not limited to, arsenic, selenium, uranium, lead, cadmium, nickel, copper, zinc, chromium and vanadium, their oxides and soluble salts thereof.

Abstract: Toxic substances such as heavy metals are extracted from a medium using a sorbent composition. The sorbent composition is derived by sulfidation of red mud, which contains hydrated ferric oxides derived from the Bayer processing of bauxite ores. Exemplary sulfidizing compounds are H2S, Na2S, K2S, (NH4)2S, and CaSx. The sulfur content typically is from about 0.2 to about 10% above the residual sulfur in the red mud. Sulfidized red mud is an improved sorbent compared to red mud for most of the heavy metals tested (Hg, Cr, Pb, Cu, Zn, Cd, Se, Th, and U). Unlike red mud, sulfidized red mud does not leach naturally contained metals. Sulfidized red mud also prevents leaching of metals when mixed with red mud. Mixtures of sulfidized red mud and red mud are more effective for sorbing other ions, such as As, Co, Mn, and Sr, than sulfidized red mud alone.

Abstract: A reducing water purification material having a reducing iron-based precipitate selected from green rust, iron ferrite, reducing iron hydroxide, and a mixture thereof. A wastewater treatment process having steps of adding a reducing iron compound to wastewater, leading the wastewater to which the reducing iron compound is added to a reaction tank and forming a precipitate, separating the formed precipitate by a solid-liquid separation to obtain a sludge, and alkalinizing all or a portion of the separated sludge to form an alkaline sludge followed by returning to the reaction tank, wherein in the precipitation step, the wastewater to which the reducing iron compound is added and the alkaline sludge are mixed and are allowed to react in a non-oxidizing atmosphere under alkaline condition to form a reducing iron compound precipitate as the precipitate, thereby incorporating contaminants in the precipitate to remove the contaminants from the wastewater.

Abstract: The disclosed invention is a fixed bed ion exchange water purification system. It employs a combination of electronically controlled process steps and specific systems configurations to duplicate the effects of moving resin beds from one operating position to another as is required in moving bed ion exchange water purification systems. The invention combines features of single fixed bed ion exchange systems with those of a moving bed system. The invention applies to the treatment of water having typical industrial and drinking water concentrations of various ions.

Abstract: The invention relates to a method for processing an aqueous effluent (E) containing in solution at least one type of metal (M) nitrite or nitrate whose oxide is stable in an aqueous medium consisting (I) in introducing cations NH4+ in aqueous solution, generally in the form of an aqueous ammonia solution, into the aqueous effluent and, subsequently (II) in processing the obtainable medium at a temperature ranging from 100 to 700° C. and a pressure of 1-50 MPa (i.e. from 10 to 500 bar), thereby converting the metal (M) nitrite or nitrate into metal (M) oxide, nitrogen and water.

Abstract: Methods to reduce hexavalent chromium (Cr(VI)) in chromite processing wastes include one or more of the following steps: contacting the chromite processing wastes with an oxygen scavenger or chemical reducer; permitting the chromite processing wastes to react with the oxygen scavenger or chemical reducer; contacting the chromite processing wastes with ferrous ion; contacting the chromite processing wastes with sulfide ion; and, contacting the chromite processing wastes with ferrous sulfide.

Abstract: Solid and liquid concrete waste is collected from a construction site and safely off-loaded at a treatment site. Solid waste is separated and sent to a crusher to be made into road bed aggregate. Liquid waste is put in a first tank to settle the solids, then moved to a second tank to settle remaining fine solids, and moved to a third tank coupled to a circulation pump with CO2 gas injection to lower the pH. The liquid in the third tank is then filtered before discharging for recycle, irrigation or dust control. A precipitate agent is preferable added to the liquid in the third tank to remove heavy metals and the precipitate is periodically backwashed from the filter into the first tank. The sludge created in the settling and filtering process is periodically dewatered in the first tank and mixed with the solid concrete waste sent to the crusher.

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 sorbent composition comprising a vanadium compound and a TiO2 support material is disclosed. Methods of making and using the composition to remove heavy metals or heavy metal containing compounds from a fluid stream are also provided. Such methods are particularly useful in the removal of mercury and mercury compounds from flue gas streams produced from the combustion of hydrocarbon-containing materials such as coal and petroleum fuels.

Abstract: An improved method to remove metals, including molybdenum, from industrial wastewater, by chemical precipitation of the metals, followed by settling and dewatering of the precipitate.

Abstract: The disclosed invention is a fixed bed ion exchange water purification system. It employs a combination of electronically controlled process steps and specific systems configurations to duplicate the effects of moving resin beds from one operating position to another as is required in moving bed ion exchange water purification systems. The invention combines features of single fixed bed ion exchange systems with those of a moving bed system. The invention applies to the treatment of water having typical industrial and drinking water concentrations of various ions.

Abstract: A method for removing fluorine from wastewater includes the steps of: adding a fluorine-reactive agent, that comprises a water-soluble sodium compound and a water-soluble aluminum compound, into the wastewater so as to form sodium ions and aluminum ions in the wastewater and so as to precipitate sodium aluminum fluoride by reaction of the sodium ions and the aluminum ions with fluorine ions in the wastewater; and removing the precipitate of sodium aluminum fluoride from the wastewater.

Abstract: The present invention relates to compositions and methods for the removal of toxic metals or radionuclides from source materials. Toxic metals may be removed from source materials using a clay, such as attapulgite or highly cationic bentonite, and chitin or chitosan. Toxic metals may also be removed using volcanic ash alone or in combination with chitin or chitosan. Radionuclides may be removed using volcanic ash alone or in combination with chitin or chitosan.

Abstract: A process is intended to allow simple and particularly reliable electrolyte generation and conditioning from metal-containing used electrolytes and/or used process solutions and/or pulverulent metal wastes. For this purpose, waste products containing metal ions from metal surface treatment processes are to be treated by producing and/or using a metal ion mixed solution, replacing anions contained in the metal ion mixed solution with anions selected for an intended use selected and selectively removing metal ions which are categorized as unsuitable for the intended use selected from the metal ion mixed solution prepared in this way.

Abstract: A method for recycling sludge during waste-water treatment firstly utilizes a process of chemical coagulation to produce sludge rich in copper ions. The sludge is then leached in a sulfuric acid storage tank with sulfuric acid of concentration 1-2N, whereby a extractive solution with copper enrichment 18-39 g/L and residues can be obtained. The extractive solution is then processed in a refrigeration crystallization tank to form copper sulfate crystals. Further, the residues produced are added into the coagulation tank as a coagulant in the process of chemical coagulation for wastewater treatment, thereby achieving a goal of zero sludge production.

Abstract: The present invention relates to the development of an improved methodology for adsorption and subsequent reduction of hexavalent chromium aimed at the total removal of hexavalent chromium in water, which comprises, reacting dichromate solutions with natural ferrous-saponite clays at temperature 50 to 200° C. for the period of 1 to 3.0 hours.

Abstract: Method for removal of heavy metal ions from aqueous wastes, which are produced during electroplating and other industrial processes. The method comprises a precipitation process that is conducted in a magnetic field.

Abstract: A two-step chemical precipitation process involving hydroxide precipitation and sulfide precipitation combined with “field separation ” technology such as magnetic separation, dissolved air flotation, vortex separation, or expanded plastics flotation, effectively removes chelated and non-chelated heavy metal precipitates and other fine particles from water. In the first-step, the non-chelated heavy metals are precipitated as hydroxides and removed from the water by a conventional liquid/solids separator such as an inclined plate clarifier to remove a large percentage of the dissolved heavy metals. The cleaned water is then treated in a second precipitation step to remove the residual heavy metals to meet discharge limits. In the second precipitation step, any metal precipitant more effective than hydroxide for metal precipitation can be used.

Abstract: The present invention relates to a product for, and a method of, treating gases, fumes and vapors with fragments of crustacean shell so as to extract one or more components/pollutants from the gases.

Abstract: A process and medium for decontamination of water containing anionic species including arsenic and chromium, wherein compounds comprising divalent and trivalent metal oxides and sulfides are used to form surface complexes with contaminants under pH conditions within the range of potable water. In one embodiment natural and synthetic spinels and spinel-like materials are used as the sorbent substance.

Abstract: The invention relates to a particular polymer which is derived from a copolymer polysaccharide formed by a main chain comprising similar or different anhydrohexose units and branches including at least one neutral or anionic anhydropentose and/or anhydrohexose unit. Moreover, the invention relates to the use of said polymer in the treatment of aqueous media, in particular the treatment of aqueous effluents containing heavy metals, the treatment of waste water, drinking water and for sludge conditioning. Said derivative polymer comprises one or more units bearing an oxime function at least at position C2.

Abstract: A method for treating a subsurface formation with a ferrous compound, to reduce a contaminant therein, involves introducing into the subsurface formation a ferrous compound in combination with sodium hydrosulfite in an amount sufficient to substantially prevent precipitation, during the introducing, of a major portion of the ferrous compound. The method was found to be useful in the reduction of hexavalent chromium to trivalent chromium at a Superfund site.

Abstract: A chemical process for detoxifying spent CCA (copper, chrome, arsenic)—treated wood, from which CCA and detoxified wood are recovered for recycling comprising the steps of (a) treating CCA-treated wood in the presence of a liquefying reagent such as an organic solvent at 100–250° C. with or without ferrous ions to form liquefied CCA-treated wood (b) adding water or an aqueous solution of an organic solvent to the liquefied CCA-treated wood with stirring to obtain an aqueous solution of liquefied CCA-treated wood (c) adding complexing or precipitating agents, such as phosphoric acid or calcium hydroxide to the aqueous solution of step (b) thereby precipitating insoluble heavy metal complexes or precipitates and forming a solution of detoxified CCA-treated wood (d) separating said heavy metal complexes or precipitates from the solution of detoxified liquefied CCA-treated wood and (e) isolating chromated copper arsenate from said heavy metal complex or precipitate.

Abstract: A method for in situ bioremediation of contaminants in the environment is described. The method includes adding an electron donor to ground water in an amount sufficient for a microbe in the ground water to use the electron donor for reducing the contaminant into an innocuous derivative thereof. Illustratively, the electron donor contains about 0.1 to 75% by weight of chitin, such as crustacean shell, partially deproteinized crustacean shell, ground mushrooms, or a fungal fermentation broth. The chitinous electron donor can be added to the ground water as a particulate solid or aqueous slurry.

Abstract: An improved water decontamination process comprising contacting water containing anionic contaminants with an enhanced coagulant to form an enhanced floc, which more efficiently binds anionic species (e.g., arsenate, arsenite, chromate, fluoride, selenate, and borate, and combinations thereof) predominantly through the formation of surface complexes. The enhanced coagulant comprises a trivalent metal cation coagulant (e.g., ferric chloride or aluminum sulfate) mixed with a divalent metal cation modifier (e.g., copper sulfate or zinc sulfate).

Abstract: Systems and methods are provided for the removal and disposal of chromium form an aqueous medium. The systems and methods include the removal of chromium from a source by contact with either natural or synthetic zeolite that has been modified with a ferrous ion or other like substance. The spent zeolite is disposed of and replaced with freshly modified zeolite. In some cases the systems and methods are performed under de-oxidizing conditions.

Abstract: The invention is related to a method and an installation for removal of metal cations contained in a liquid, in which said liquid is brought into contact at a temperature greater than or equal to 60° C. with a chelating ion exchange resin formed from a polyazacycloalkane grafted on a solid support, said resin having been conditioned, previously to said contacting, at a pH of 4 to 6.

Abstract: A process and medium for decontamination of water containing anionic species including arsenic and chromium, wherein compounds comprising divalent and trivalent metal oxides and sulfides are used to form surface complexes with contaminants under pH conditions within the range of potable water. In one embodiment natural and synthetic spinels and spinel-like materials are used as the sorbent substance.

Abstract: A process for the selective removal of toxic heavy metals from a flowing stream of water involves causing the stream to flow through a stationary bed of particulate polymer having amine functional groups, and injecting into the stream, adjacent the upstream extremity of the bed, a substantially continuous flow of carbon disulfide.

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 water filtration device (3) and method which removes heavy metals and organic compounds from raw water is provided.

Abstract: Methods and apparatus are disclosed for remediating metal contaminants using hydrocarbons which stimulate the growth of hydrocarbon-utilizing bacteria. The metal contaminants may include heavy metals such as arsenic, antimony, beryllium, cadmium, chromium, copper, lead, mercury, iron, manganese, magnesium, radium, nickel, selenium, silver, thallium and zinc. The hydrocarbon may include alkanes, alkenes, Aalkynes, poly(alkene)s, poly(alkyne)s, aromatic hydrocarbons, aromatic hydrocarbon polymers and aliphatic hydrocarbons. Butane is a particularly suitable hydrocarbon which stimulates the growth of butane-utilizing bacteria. Remediation may occur in-situ or ex-situ, and may occur under aerobic, anaerobic or dual aerobic/anaerobic conditions. Examples of applications include the remediation of heavy metals, the remediation of arsenic impacted surface water, groundwater and/or soil, the remediation of acid mine drainage, and the treatment of spent metal plating solutions.

Abstract: A two-step chemical precipitation process involving hydroxide precipitation and sulfide precipitation combined with “field separation” technology such as magnetic separation, dissolved air flotation, vortex separation or expanded plastics flotation, effectively removes chelated and non-chelated heavy metal precipitates and other fine particles from water. In the first-step, the non-chelated heavy metals are precipitated as hydroxides and removed from the water by a conventional liquid/solids separator such as an inclined plate clarifier to remove a large percentage of the dissolved heavy metals. The cleaned water is then treated in a second precipitation step to remove the residual heavy metals to meet discharge limits. In the second precipitation step, any metal precipitant more effective than hydroxide for metal precipitation can be used.

Abstract: A product and method for the removal of pollutant heavy metals from aqueous solutions which precludes the end user from storing, handling, feeding and controlling hazardous soluble sulfide materials. The product is a slurry which includes a mixture of a liquid medium and an essentially insoluble salt wherein the salt is the reaction product of heavy metal ions, preferably selected from Mn++ ions, Fe++ ions, and Fe+++ ions, and sulfide ions derived from soluble sulfide sources such as sodium sulfide, hydrogen sulfide, and sodium hydrosulfide. Addition of the subject slurry to a wastewater stream will effect the precipitation of heavy metals with lesser equilibrium sulfide ion concentrations than that of the essentially insoluble salt. Solids collected by this method may be returned to subsequent wastewater streams for additional removal of heavy metals by any excess heavy metal sulfide salt.

Abstract: A fiber capable of forming a metal chelate and a process for producing the same are disclosed, wherein the fiber is characterized in that at least one metal chelate-forming compound selected from the group consisting of aminocarboxylic acid, aminocarboxylic acid, thiocarboxylic acid and phosphoric acid, which are reactive with a glycidyl group, is bonded to a molecule of a synthetic fiber through a crosslinkable compound having a reactive double bond and a glycidyl group in its molecule. The chelate-forming fiber is excellent in capturing harmful heavy metal ions and can be easily produced in a simple and safe way at a low cost.

Abstract: A metal waste recovery process for recovering useful material from a quantity of waste material. The waste material is a composition including oil, metals and organic materials. The first step of the process is to deposit the waste material into a slurry tank and to add water to the waste material to produce a mixable slurry. The slurry is then high energy mixed to evenly distribute the waste material throughout the slurry. The useful metal is then recovered from the slurry using a magnetic separator. The remaining waste material is transferred into an anaerobic reactor where the remaining waste material reacts with anaerobic organisms provided by bacteria in a sludge seed. The anaerobic reaction between the anaerobic organism and the organic materials of the waste material produces recoverable inorganic gases that are removed from the waste material slurry. The recovered inorganic gases are transferred to a storage vessel and compressed.

Abstract: The invention relates to a process for treating a chromate waste liquid containing an organic acid component. This process includes (a) adding a chromium precipitation accelerating agent containing at least one of a calcium component and a magnesium component, to the chromate waste liquid; and (b) adjusting the chromate waste liquid to having a first pH of 9 or higher, thereby precipitating a chromium component from the chromate waste liquid and thereby reducing a concentration of a dissolved chromium component of the chromate waste liquid.

Abstract: A bead is provided which comprises or consists essentially of activated carbon immobilized by crosslinked poly(carboxylic acid) binder, sodium silicate binder, or polyamine binder. The bead is effective to remove metal and other ionic contaminants from dilute aqueous solutions. A method of making metal-ion sorbing beads is provided, comprising combining activated carbon, and binder solution (preferably in a pin mixer where it is whipped), forming wet beads, and heating and drying the beads. The binder solution is preferably poly(acrylic acid) and glycerol dissolved in water and the wet beads formed from such binder solution are preferably heated and crosslinked in a convection oven.

Abstract: A process for recovery of hexavalent chromium from waste streams. The method includes providing a waste stream containing hexavalent chromium, reacting a soluble non-toxic precipitating reagent with the hexavalent chromium to form an insoluble precipitating reagent-chromate precipitate, and recovering the insoluble precipitating reagent-chromate precipitate. It may optionally include reacting the insoluble precipitating reagent-chromate precipitate with an acidic solution to form an insoluble precipitating reagent precipitate and a soluble hexavalent chromium compound, and recovering the soluble hexavalent chromium compound. The process may also include reacting the insoluble precipitating reagent precipitate with a solubilizing reagent to form the soluble non-toxic precipitating reagent.

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.