Heavy Metal Patents (Class 210/912)
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Patent number: 5492680Abstract: A process for separating scandium from an aqueous solution comprised of a first group of metals, scandium and a second group of metals includes the steps of: (a) providing a scandium-containing material and preparing therefrom an aqueous sulfuric acid solution containing a first group of metals, scandium and a second group of metals; (b) contacting the aqueous sulfuric acid solution with an organic liquid solution whereby scandium and the first and second groups of metals are extracted into the organic liquid solution to create a loaded organic solution; (c) scrubbing the loaded organic liquid solution first with an sulfuric acid solution to remove selected metals in the first group of metals from the organic liquid solution and then with a dilute HF solution to prepare the organic liquid solution for stripping; (d) stripping the remaining metals in the first group of metals from the loaded organic liquid solution with a HF solution so that only scandium and the second group of metals remain on the organic liType: GrantFiled: August 4, 1994Date of Patent: February 20, 1996Assignee: The United States of America as represented by the Secretary of the InteriorInventor: Michael D. Odekirk
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Patent number: 5476593Abstract: A method of removing undesired precipitate from the surfaces of an apparatus; wherein the apparatus is used in a process for removing silver from silver bearing photoprocessing solutions and the process includes the step of mixing a mercapto-s-triazine, or a water soluble salt thereof, with a silver bearing photoprocessing solution, thereby causing formation of the undesired precipitate and a precipitate of silver mercapto-s-triazine, said method comprising flushing inner surfaces of the apparatus with an aqueous solution having a pH of at least 9.8 thereby solubilizing the undesired precipitate.Type: GrantFiled: December 8, 1994Date of Patent: December 19, 1995Assignee: Eastman Kodak CompanyInventors: Charles S. Christ, Albert R. Szembrot
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Patent number: 5472618Abstract: A method for recovering metals from solutions is described. A particular embodiment of the method concerns recovering copper metal. The method comprises first treating a solution containing copper ions with a sufficient amount of an inorganic acid to obtain a solution pH of from about 1.5 to less than about 2.5. A reducing metal, such as iron, is then added to the solution to precipitate metal ions, such as copper ions, as metals. The reducing metal has a mesh size preferably smaller than about 350, and even more preferably at least as small as about 400 mesh. The metal precipitate is recovered from solution.Type: GrantFiled: February 7, 1994Date of Patent: December 5, 1995Assignee: Great Western Chemical CompanyInventor: Daniel G. Bolser
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Patent number: 5462670Abstract: A process for removing dissolved oils and greases from an aqueous solution which also may contain dissolved heavy metals is provided wherein the aqueous solution is mixed with a source of ferrous ion and dithionite ion in a first step at acidic pH to reduce and permit removal of solid heavy metal, is present and to separate oils and greases from the aqueous solution. Solution from the first step if reacted in a second step with hydroxide slurries obtained from third and fourth steps. A second step solution from the second step is reacted in a third step with an alkali composition and a third solution. Optionally, the third solution is reacted with a chelating agent for iron and an oxidizer in a fourth step. A solution of chelated iron from the fourth step, when practical is disposed of. Oils and greases are recovered from the first step such as by skimming.Type: GrantFiled: March 28, 1994Date of Patent: October 31, 1995Assignee: Romar Technologies, Inc.Inventor: Robert G. Guess
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Patent number: 5462671Abstract: Disclosed is a method to remove heavy metals from amino-carboxylic acid chelate solutions comprising adding nitrous acid to lower the pH of the aqueous solution sufficient to destroy the chelate bonds and release the metal ions and thereafter adding an appropriate strong base and optionally a sulfide salt to precipitate the liberated heavy metals.Type: GrantFiled: September 8, 1994Date of Patent: October 31, 1995Assignee: HydroChem Industrial Services, Inc.Inventors: Stephen T. Arrington, Gary W. Bradley
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Patent number: 5458787Abstract: Carbonaceous pyropolymers possessing recurring units containing at least carbon and hydrogen atoms on their surface are effective in removing from solution metal cations having a standard reduction potential to their zerovalent state of greater than -0.2 volts. Their mode of action appears to be via reduction of the metal to the zerovalent state which then is deposited on the pyropolymer surface.Type: GrantFiled: October 27, 1994Date of Patent: October 17, 1995Assignee: UOPInventors: Richard R. Rosin, William C. Schwerin
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Patent number: 5454948Abstract: The present invention relates to a semi-continuous process for removing heavy metals, substantially reducing volatile suspended solids and substantially destroying indicator bacteria from municipal sludges, which comprises: a) adding 1 to 3 g of sulphur per liter to a volume of municipal sludge and allowing the sulphur oxidizing thiobacilli initially present in said sludge to proliferate under aerobic conditions in said sludge being agitated until the pH of said sludge is lowered to about 1.5 to 2.Type: GrantFiled: August 23, 1993Date of Patent: October 3, 1995Assignee: Institut National de la Recherche ScientifiqueInventors: Rajeshwar D. Tyagi, Jean-Francois Blais, Jean C. Auclair
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Compound and method for treating water containing metal ions and organic and/or inorganic impurities
Patent number: 5451327Abstract: A composition for treating water that contains metal ions and possibly also organic and/or inorganic compounds is produced by reacting sulfur with an alkali- and/or alkaline earth metal hydroxide in the presence of water.The inventive composition corresponds to general formula IM.sub.x S.sub.y O.sub.z, (I)whereM represents an alkali or alkaline earth metal,x is 1 or 2,y is in the range 1.5x-2.5x, andz is in the range 0.1-2.5.Type: GrantFiled: March 18, 1993Date of Patent: September 19, 1995Inventor: Gunter Straten -
Patent number: 5449460Abstract: A process is provided for the treatment of water containing sulphide wherein the sulphide is oxidized in an aerobic reactor having a minimum sulphide sludge load. The minimum sulphide load is at least 10 mg of sulphide per mg of the nitrogen present in the sludge per hour, the sludge load being calculated on the basis of the sulphide oxidizing part of the biomass. The minimum sulphide load may also be defined as 25 mg of sulphide per liter of reactor material per hour. The sulphide can be largely oxidized to elemental sulphur which is then separated and reused. Waste water also containing organic matter in addition to varying levels of sulphide is purified without interference of filamentous bacteria using a two-step aerobic process. The process for sulphide removal can be used for the treatment of waste water having high levels of sulphur compounds such as sulphate, sulphite and thiosulphate by first reducing these sulphur compounds in an aerobic step.Type: GrantFiled: December 15, 1993Date of Patent: September 12, 1995Assignee: Paques B.V.Inventor: Cees J. Buisman
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Patent number: 5443729Abstract: A process for removal of manganese from water which includes the steps of (i) preparing a fluidized bed of particles (eg. magnetite) in a bioreactor capable of adsorbing a strongly adherent biofilm of microorganisms (e.g. pedomicrobium manganicum) metabolising manganese to provide an actively propagated biomass, and (ii) passing a stream of water through the fluidized bed where manganese is adsorbed by said biomass and is thus removed from the stream of water to provide a purified effluent of water exiting from the bioreactor.Type: GrantFiled: May 9, 1994Date of Patent: August 22, 1995Assignees: The University of Queensland, Commonwealth Scientific and Industrial Research OrganizationInventors: Lindsay I. Sly, Vullapa Arunpairojana, David R. Dixon
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Patent number: 5441641Abstract: A process is provided for reducing the concentration of water soluble ionic manganese species in aqueous waste solutions containing the same. The process comprises passing said waste solution through a treatment zone containing a porous matrix on which are retained populations of at least one manganese oxidizing bacterium, such as members of the genus Metallogenium. The passing of said aqueous solution through said treatment zone is carried out at predetermined rates of flow, and contact between said solution and said bacteria is conducted under aerobic conditions and at predetermined pH and temperature levels. The process provides for the conversion of water soluble ionic manganese species to water insoluble manganese oxides, which are retained on the porous matrix and can be recovered therefrom.Type: GrantFiled: December 17, 1993Date of Patent: August 15, 1995Inventors: William J. Vail, Robert K. Riley
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Patent number: 5441648Abstract: Heavy metals are separated from aqueous media containing the same by contacting the said medium with finely divided iron oxide (Fe.sub.3 O.sub.4) and finely divided ferrous sulphide, maintaining said contact until at least a substantial proportion of said heavy metal has become bound to said iron oxide and ferrous sulphide, and then separating the iron oxide and ferrous sulphide having heavy metal bound thereto from the aqueous medium.Type: GrantFiled: May 16, 1994Date of Patent: August 15, 1995Assignee: Bio-Separation LimitedInventor: Raymond G. Lidzey
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Patent number: 5439584Abstract: Apparatus combination and system for reducing use of fresh water in a photoprocessing operation by recirculation of the wash water to the photoprocessing operation via a silver recovery system. Wash water is periodically discharged to waste and a like amount of fresh water is added to the system which serves to reduce the concentration of thiosulfate ions in the wash water.Type: GrantFiled: May 29, 1992Date of Patent: August 8, 1995Inventor: Gerson J. Rosenfield
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Patent number: 5437792Abstract: A process for removing silver from a silver containing photoprocessing solution, including the steps of:a) mixing a mercapto-s-triazine, or a water soluble salt thereof, with the solution thereby causing formation of a mixture of i) precipitates and fines of silver mercapto-s-triazine and ii) the solution;b) mixing a copolymer flocculant with the mixture thereby causing flocculation and agglomeration of the silver TMT fines; wherein the copolymer i) consist of monomers selected from the group consisting of acryloyloxyethyl trimethylamine chloride and acrylamide and ii) has a reduced viscosity of 21 to 30 dL/g.Type: GrantFiled: July 27, 1994Date of Patent: August 1, 1995Assignee: Eastman Kodak CompanyInventors: Albert R. Szembrot, Charles S. Christ, Jr.
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Patent number: 5433864Abstract: The invention discloses a method for treating a heavy metal containing waste water by using acorns. Acorns and nuts of other trees belonging to the Eagaceae group are dried at the room temperature and under the sun beams. Then acornic acid is extracted from the dried acorns. Then the acornic acid is filtered until it becomes colorless. A heavy metal containing waste water (low concentration and high concentration) is maintained at pH=8-11.5 by adding NH.sub.4 OH, Ca(OH).sub.2 and NAOH. Then the acornic acid is added into the waste water, and then, Ca.sup.++ ions singly or together with other divalent cations are added by 50 ppm. Then this solution is agitated for several minutes, and then, the heavy metals are precipitated, or the solution is filtered, thereby treating the heavy metal containing waste water.Type: GrantFiled: May 11, 1994Date of Patent: July 18, 1995Assignee: Korea Atomic Energy Research InstituteInventors: Myung-Whan Yun, Jang-Jin Park, Yun-Whan Lee, In-Soon Chang, Jae-In Sin
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Patent number: 5431825Abstract: A method for reducing reducible metals comprising combining one or more reducible metals with an elemental metal, and then with a reducing agent to form a reduced metal. The mixture may then be stabilized and recovered.Type: GrantFiled: October 29, 1992Date of Patent: July 11, 1995Assignee: Chemical Waste Management, Inc.Inventor: Bruce N. Diel
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Patent number: 5429751Abstract: A method for immobilizing material contaminated with heavy metal ions, a fixant for immobilizing heavy metal ions and a matrix.A method is disclosed for immobilizing material contaminated with heavy metal ions, said metal ions in a liquid environment being allowed to react with a metal-complexing agent with the formation of a metal complex, the metal-complex formed being mixed, in the presence of water, with an inorganic, hydraulic binder comprising blast furnace slag cement, fly ash cement or a combination thereof to form a matrix having reductive properties in the form of a hard, rocklike material, which method is characterized in that said metal complex is formed in the presence of a metal-complex bond activator. Said metal-complex bond activator is preferably a water-soluble salt of a transition metal element, expediently ferric chloride or manganese sulphate.Type: GrantFiled: August 22, 1994Date of Patent: July 4, 1995Assignee: Pelt & Hooykaas B.V.Inventor: Carel W. J. Hooykaas
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Patent number: 5427691Abstract: A lime-treatment method is disclosed to neutralize acidic waters containing heavy metals and sulphate and precipitate the metals as hydroxides along with calcium sulphate solids which are called sludge. The method comprises neutralizing the water in two reactors, the pH of the first reactor being increased to 4-4.5 using a predetermined amount of recycled sludge to precipitate only ferric hydroxides whereas other metal hydroxides coming from the recycled sludge are dissolved, the pH of the second reactor being increased to 9-10 using a mixture of lime and a small amount of the sludge recycled to the first reactor; feeding the ferric hydroxides precipitated in the first reactor to the second reactor to act as nuclei in the second reactor to promote crystallization; and introducing air into the second reactor to oxidize ferrous iron to less soluble ferric iron which results in formation of a more stable sludge compared to ferrous sludge.Type: GrantFiled: October 22, 1993Date of Patent: June 27, 1995Assignee: Noranda, Inc.Inventors: Nural Kuyucak, Tamara Sheremata
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Patent number: 5423990Abstract: A process is disclosed for the purification of waste water containing a silver compound, comprising the steps of (1) adding to said waste water a salt of a poly(guanidine) or poly(biguanidine) polymer (2) adding a flocculant, and (3) filtrating the formed flocculate.The invention is particularly suitable for the removal of silver from the effluent of a photographic processor, and more specifically the effluent of a processor of wash-off materials, said effluent also containing gelatin.A most preferred poly(guanidine) compound is poly(hexamethyleneguanidine) hydrochloride.Type: GrantFiled: December 30, 1993Date of Patent: June 13, 1995Assignee: AGFA-Gevaert, N.V.Inventors: Eddy Michiels, Frank Michiels, Dmitry A. Topchiev, Gennady G. Kardash
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Patent number: 5415778Abstract: A method and related product for purification of waste water, especially of water polluted with phosphorus, nitrogen, heavy metals, and chlorinated solvents. The purification process consists of:a) adding two liquid mixtures in sequence to the waste water;b) letting the pollutants react with the two mixtures;c) subsequently removing the sludge that forms.One of the two liquid mixtures in question is a liquid mixture of two acids that may be extracted from lignite, leonardite and fossils of vegetal origin like peat.Type: GrantFiled: February 28, 1994Date of Patent: May 16, 1995Assignee: HydroGeo North America L.L.C.Inventors: Roberto Zanin, Gaetano Boetti
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Patent number: 5407576Abstract: In a process for removing organic impurities and heavy metals from industrial, commercial or communal waste water, loaded drinking water, refuse dump drainage water or aqueous special wastes, the wet pyrolysis residues produced during the extraction of usable gas in the pyrolytic processing of refuse are introduced into one or more aerated filter basins (17) or filtration reactors (26) connected in parallel or in series. The waste water, loaded drinking water, refuse dump drainage water or liquid special wastes to be filtered or purified are pumped through the pyrolysis residue until its capacity for physical adsorption is exhausted.Type: GrantFiled: November 20, 1992Date of Patent: April 18, 1995Assignee: PKA Pyrolyse Kraftanlagen GmbHInventors: Bernd M. Wolf, Claus Frischkorn, Peter Dolderer
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Patent number: 5407650Abstract: A process for purifying an acidic technical-grade iron chloride solution formed from cyclone dust from the production of TiO.sub.2 in accordance with the chloride process by adjusting the pH with a first neutralizing agent and thereafter introducing the pH adjusted solution in a controlled manner into a solution containing a second neutralizing agent. In this process undesired ions which are to be separated, such as chromium, vanadium, zirconium and/or niobium, precipitate in the form of efficiently filterable hydroxides which can be separated industrially under economical conditions by filtration. The filter cake is non-hazardous and can safely be disposed of by dumping. Calcium carbonate is the preferred neutralizing agent, and the pH adjustment may also advantageously be effected by using scrap iron or by using iron sinters with reduction of any Fe(III) ions before the second neutralization step.Type: GrantFiled: December 21, 1993Date of Patent: April 18, 1995Assignee: Kronos, Inc.Inventors: Achim Hartmann, Ulrich Rothe, Dieter Schinkitz
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Patent number: 5403488Abstract: The present invention provides a process for the regulation of the activa sludge step of a clarification plant by control of the decomposition efficiency of the activated sludge, wherein an activated sludge sample is incubated under precisely defined conditions, which are optimised with regard to the pH value, the temperature and the salt concentration, with the substrate or substrates of interest above the saturation range and, in the initial phase, the decrease of the substrate or the increase of a decomposition product is determined kinetically as a measure of the decomposition efficiency for this substrate and the measured value determined is used as regulating value for the control of the clarification plant.Type: GrantFiled: January 24, 1994Date of Patent: April 4, 1995Assignee: Orpegen Medizinisch-Molekular-Biologische Forschungsgesellschaft mbHInventors: Andreas Volsch, Werner Nader
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Patent number: 5403496Abstract: A process for stabilizing metals in ash to prevent leaching of the metals is disclosed. The pH of an aqueous slurry of ash is reduced to less than 5 in the presence of an iron salt. The pH-reduced slurry is then treated with an organo sulfur containing compound and an alkaline earth metal oxide or hydroxide in specific weight proportions relative to the iron salt and to each other.Type: GrantFiled: March 31, 1994Date of Patent: April 4, 1995Assignee: Drew Chemical CorporationInventors: Mark G. Kramer, Kathleen A. Fix
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Patent number: 5401416Abstract: A drinking water filter for removing lead at point-of-use composed of specially treated gamma alumina particles between 48 and 100 mesh (0.148-0.297 mm), gamma alumina neutral (about 7 surface pH) or basic (about 9 surface pH) is washed in highly purified H.sub.2 O at 100.degree. C. to reduce alumima surface pH to 3.5-5.0 and then washed with highly purified H.sub.2 O at ambient temperature. The alumina is placed for three to twelve hours in bath having equivalent pH value (3.5-5.0) of acid electrolyte, diluted with a highly purified H.sub.2 O, preferably HCl, ascorbic acid or EDTA, adjusted to alumina surface pH level and desired degree of dilution by salts such as NaCl and/or alkalies such as NaOH to transfer to adsorbent surface materials that effect selective ion exchange with lead and other heavy metal ions or otherwise cause their removal from drinking water. Upon removal of alumina from bath, it is vacuum washed and then dried in an oven at 200.degree. C. to 350.degree. C. for about two hours.Type: GrantFiled: July 27, 1992Date of Patent: March 28, 1995Inventor: Ehud Levy
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Patent number: 5401420Abstract: A wastewater treatment system and method for chemical precipitation and removal of metals from wastewater in a continuous or batch treatment process includes an ion-selective sulfide electrode and a reference electrode disposed in a precipitation tank for measuring an electrochemical potential therebetween in a predetermined range. A controller unit is provided which is responsive to the electrochemical potential in the predetermined range and is connected to a precipitant feed unit for automatically controlling the chemical precipitant fed into the precipitation tank.Type: GrantFiled: March 23, 1994Date of Patent: March 28, 1995Assignee: Nalco Chemical CompanyInventors: Kristine S. Siefert, Pek L. Choo, Wayne M. Carlson
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Patent number: 5395534Abstract: Disclosed is a water filtration medium capable of removing heavy metals from ground water and surface supplies. This medium comprises a gamma form of manganese dioxide that has been comminuted and divided into fractions according to mesh size, including fractions of 10 to 40 mesh, 40 to 100 mesh, and 100 to 325 mesh. The particles in a given mesh size are treated with a reducing agent such as ferrous sulfate and then washed with water to remove iron precipitates and fines. The washed particles are treated with a solution of sodium hydrosulfite and sodium bisulfite. The treated particles are then neutralized with sodium hydroxide to remove remaining acidity. The neutralized particles are washed again in order to remove spent chemicals and undissolved metals. The particles are then dried prior to use as a filtration medium. Also disclosed is a disposable cartridge for housing the filtration medium, a method of using the medium, and a means for preparing the medium.Type: GrantFiled: November 2, 1992Date of Patent: March 7, 1995Assignee: Sterling Air & Water CorporationInventor: James K. Smith
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Patent number: 5393426Abstract: A process for the removal of metal ions from solution and means for effecting such removal are described. The process is based on the hydroponic growth of sunflowers, terrestrial turfgrasses and/or members of the family Brassicaceae in solutions containing one or more metal ions. Metal ions can be efficiently removed from solutions by passing these solutions through the root biomass of these terrestrial plants. Columns containing the root biomass are also part of the invention.Type: GrantFiled: June 4, 1993Date of Patent: February 28, 1995Assignee: PhytoTech, Inc.Inventors: Ilya Raskin, Slavik Douchenkov, Yoram Kapulnik, Nanda P. B. A. Kumar
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Patent number: 5389262Abstract: Heavy metal ions react with ferrous dithionite in acidic aqueous solution. They are reduced to metallic particles that are suitable for recycling and reuse when recovered from the acidic water. Chelating agents that are present are deactivated by bonding to the ferrous ions. Ferrous dithionite, (FeS.sub.2 O.sub.4) is either generated in-situ or ferrous ions and dithionite ions can be provided by other methods. An alkali metal hydroxide is utilized to precipitate remaining heavy metal ions including ferrous and ferric ions.Type: GrantFiled: March 28, 1994Date of Patent: February 14, 1995Assignee: Romar Technologies, Inc.Inventor: Robert G. Guess
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Patent number: 5384036Abstract: A method of treating chemical liquid, and in particular photographic effluent, to render it more environmentally acceptable, by the addition to an alkaline solution of a salt of a Group III or transition metal to complex with and precipitate out a sequestering agent. Preferred salts are the sulphate, halide, oxychloride or nitrate of aluminium.Type: GrantFiled: March 4, 1993Date of Patent: January 24, 1995Assignee: Eastman Kodak CompanyInventor: John R. Fyson
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Patent number: 5380443Abstract: A process of treating water to remove metal ion contaminants contained therein, said metal ion contaminants selected from the group consisting of metals in Groups 8, 1b, 2b, 4a, 5a, or 6a of the periodic table, lanthanide metals, and actinide metals including transuranic element metals, by adjusting the pH of a metal ion contaminant-containing water source to within the range of about 6.5 to about 14.0, admixing the water source with a mixture of an alkali or alkaline earth ferrate and a water soluble salt, e.g., a zirconium salt, in an amount sufficient to form a precipitate within the water source, the amount the mixture of ferrate and water soluble salt effective to reduce the metal ion contaminant concentration in the water source, permitting the precipitate in the admixture to separate and thereby yield a supernatant liquid having a reduced metal ion contaminant concentration, and separating the supernatant liquid having the reduced metal ion contaminant concentration from the admixture is provided.Type: GrantFiled: November 7, 1991Date of Patent: January 10, 1995Assignee: The Regents of the University of CaliforniaInventors: James P. Deininger, Linda K. Chatfield
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Patent number: 5372726Abstract: A compound for the treatment of water polluted by metal ions is obtained by the reaction of potassium or sodium hydroxide in aqueous solution with thiocarbamide and potassium or sodium hyposulfate. After a period of settling, a precipitate forms and is removed; the clear liquid above the precipitate is decanted and used for treating water polluted with metal ions.Type: GrantFiled: November 3, 1993Date of Patent: December 13, 1994Inventor: Gunter Straten
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Patent number: 5370801Abstract: A method for treating polluted material such as industrial waste water or polluted water from other sources, sewage or sewage sludge, or other forms of sludge, to degrade oxidizable substances therein. The polluted material is subjected to a wet oxidation process in a tubular reactor so as to decompose and/or modify oxidizable substances therein and improve the filterability of any solids present in the material. The material may also be pretreated to facilitate the wet oxidation process. Solid polluted material is preferably in the form of an aqueous suspension when subjected to wet oxidation. The wet oxidation process is performed to such an extent that the decomposed and/or modified substances remaining after the oxidation step are substantially biodegradable. Heavy metals may also be removed subsequent to the wet oxidation process.Type: GrantFiled: January 5, 1993Date of Patent: December 6, 1994Assignee: Conor Pacific Environmental Technologies, Inc.Inventors: Emil Sorensen, Jorgen Jensen, Erik Rasmussen, Bror S. Jensen, Belinda Bjerre
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Patent number: 5370800Abstract: A method for removing metal compounds from waste water comprising the steps of adjusting the pH of the water to from 5 to 12 and preferably 6 to 9; aerating the waste water; adding a flocculating agent to the water and allowing floccules including metal compounds to form; and separating said floccules including metal compounds from the water. An apparatus for carrying out this method is also disclosed.Type: GrantFiled: May 25, 1993Date of Patent: December 6, 1994Inventor: Sanford M. Stevenson
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Patent number: 5368741Abstract: Aqueous phosphorus wastes from the electric furnace production of phosphors and containing heavy metal bearing particulates are treated with lime whereby the phosphorus is converted into useful phosphorus compounds and the heavy metals rendered sufficiently non-leachable to permit their release into the environment. The treatment is conducted above about 60.degree. C. at a pH of between about 11.0 to 12.5.Type: GrantFiled: October 12, 1993Date of Patent: November 29, 1994Assignee: FMC CorporationInventors: Theodore F. Munday, Jay R. Brummer, Paul J. Beck
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Patent number: 5366640Abstract: Converting wet-process phosphoric acid operations, to minimize and nearly eliminate discharge of contaminants to the environment, by generation, use, and treatment of new and unique process waters. Fluorides and other contaminants soluble under acidic conditions are insolubilized, and substantially all phosphoric acid is recovered. Acid pond water from conventional wet-process phosphoric acid manufacturing is replaced by neutralized gypsum stack water having a pH closely matching that of the surroundings. Both air and ground water contamination are reduced to essentially negligible levels.Type: GrantFiled: September 14, 1993Date of Patent: November 22, 1994Inventors: Gordon W. Palm, by Marcella W. Palm, Legal Representative, R. George Hartig
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Patent number: 5366715Abstract: The present invention is concerned with a method for selectively removing antimony and bismuth from an impure sulphuric acid solution containing at least 50 g/L of acid and some concentration of ferric ion (for example copper refinery electrolyte), is disclosed. The method involves contacting the impure solution with a sufficient quantity of finely divided metallic copper so as to prereduce all ferric ion present in the solution to the ferrous oxidation state. The prereduced solution is then contacted with a chelating resin. The method avoids the deleterious loading of ferric iron onto the ion exchange resin and prevents the return of excessive amounts of chloride ion with the purified electrolyte.Type: GrantFiled: October 19, 1993Date of Patent: November 22, 1994Assignee: The University of British ColumbiaInventors: David B. Dreisinger, Brenna J. Y. Leong
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Patent number: 5360514Abstract: In the bleaching of paper pulp without chlorine, such as using an OTZE or OZP bleach sequence, filtrate from subsequent stages is used as a wash liquid in preceding wash stages. The filtrate is treated with a fiber filter, and then passes through a magnesium filter, which has magnesium chips with a maximum dimension of about 3 mm or less. The magnesium removes heavy metal ions, and if any of the magnesium dissolves in the filtrate it provides a beneficial affect on the pulp. The pH of the filtrate is typically maintained in the 2-6 range to facilitate dissolution of Cu, Mn and Fe while the magnesium stays out of solution. Two filters may be provided in parallel so that if one becomes contaminated the other may be quickly put into service, and any explosive gases from the magnesium filter are vented.Type: GrantFiled: March 15, 1993Date of Patent: November 1, 1994Assignee: Kamyr, Inc.Inventors: Kaj Henricson, Anja Klarin
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Patent number: 5354478Abstract: An aqueous solution of sodium borohydride, sodium hydroxide, and an anionic polymer is useful for the reduction and separation of metals in wastewater and it is hydrolytically stable for a period of six months. It may also contain an alkali metal aluminate or alum. Thus, a one-package treatment of wastewater is provided by the invention described herein.Type: GrantFiled: June 9, 1993Date of Patent: October 11, 1994Assignee: Morton International, Inc.Inventors: Jeffrey A. Ulman, Walter Verstraeten, Michael A. Cook, Willy Verleye, Lawrence J. Guilbault
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Patent number: 5350522Abstract: A method for treating photographic effluent to remove harmful pollutants and which reduces silver and iron ion concentrations in the effluent to no more than about 2 ppm is disclosed. The method includes an oxidation step to convert reducing sulfur compounds to oxidized products; a heavy metal ion precipitation step; a step of adding a developing agent absorbent and a sequestering agent absorbent; and a step of separating a produced solid phase from a liquid phase. The separated Liquid phase is environmentally acceptable.Type: GrantFiled: March 4, 1993Date of Patent: September 27, 1994Assignee: Eastman Kodak CompanyInventor: John R. Fyson
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Patent number: 5348662Abstract: In the process of removing heavy metals from aqueous solutions (groundwater) by precipitation of a salt thereof, an oxidizing agent is optionally used to increase the valence of said metal, and a precipitation-enhancing agent is added to maximize particle size of the precipitate and to facilitate its separation from said solution.Type: GrantFiled: May 13, 1993Date of Patent: September 20, 1994Assignee: Elf Atochem North America, Inc.Inventors: Jeffrey H. Yen, Richard C. Spung
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Patent number: 5347071Abstract: A process for the treatment of contaminants using metal scavenger is disclosed. The metal scavengers individually comprise a polyamine derivative and a polyethyleneimine derivative. The polyamine derivative is formed of a polyamine having a molecular weight not higher than 500 and contains, per molecule of the polyamine, at least one dithiocarboxyl group or a salt thereof as an N-substituting group substituted for an active hydrogen atom of the polyamine. The polyethyleneimine derivative is formed from a polyethyleneimine having an average molecular weight of at least 5,000 and contains, per molecule of the polyethyleneimine, at least one dithiocarboxyl group or a salt thereof as an N-substituting group substituted for an active hydrogen atom of the polyethyleneimine.Type: GrantFiled: November 3, 1992Date of Patent: September 13, 1994Assignee: Miyoshi Yushi Kabushiki KaishaInventors: Masafumi Moriya, Kazuo Hosoda, Masatoshi Yoshida, Masayoshi Tsukanome
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Patent number: 5346627Abstract: A method is provided for removing metals from a fluid stream containing these metals. The method involves treating the fluid stream with a water soluble ethylene dichloride ammonia polymer having a molecular weight of from 500 to 100,000 that contains at least 5 mole percent of dithiocarbamate salt groups to form a complex with the metals. Then, the fluid stream is passed through a filtering device to remove the complexes from the fluid stream.Type: GrantFiled: September 20, 1993Date of Patent: September 13, 1994Assignee: Nalco Chemical CompanyInventors: Kristine S. Siefert, Pek L. Choo, John W. Sparapany, John H. Collins
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Patent number: 5346566Abstract: A multi-layer article of manufacture includes an intermediate layer of a water-swellable colloidal clay, such as bentonite, sandwiched between two layers of flexible sheet or fabric material wherein the two flexible layers of sheet or fabric material are structurally interconnected through the intermediate clay layer, such as by needle punching, after lubrication of the clay surface with a liquid, such as water, to interconnect fibers of one fabric layer to the other fabric layer at spaced locations over essentially the entire inner surface areas of both sheet or fabric material layers. In a preferred embodiment, a water-insoluble adhesive is applied to at least one of the fabric layers to lock the interconnecting fibers in place and substantially increase the structural integrity, particularly the shear strength, of the article.Type: GrantFiled: December 16, 1992Date of Patent: September 13, 1994Assignee: American Colloid CompanyInventor: Alec W. White
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Patent number: 5344572Abstract: A method for treating waste pickle liquor solution comprising the steps of (a) adding a flocculating agent to the pickle liquor solution; (b) allowing at least some of the silica in the pickle liquor to begin to flocculate; (c) again adding a flocculating agent to the pickle liquor solution; (d) allowing the floccules containing silica formed in step (b) to increase in size; and (e) physically separating floccules formed in step (d) from the pickle liquor solution.Type: GrantFiled: July 10, 1992Date of Patent: September 6, 1994Inventor: Satish C. Wadhawan
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Patent number: 5338460Abstract: A process is disclosed for the removal of dissolved heavy metals from aqueous solution contaminated therewith wherein at least one of said heavy metals is reacted with a water-soluble inorganic sulfide or hydrosulfide at a defined elevated temperature and a controlled pH of between about 2 to about 3.5 to thereby precipitate heavy metal sulfide, and thereafter separating the precipitate from the filtrate.Type: GrantFiled: April 22, 1993Date of Patent: August 16, 1994Assignee: Elf Atochem North America, Inc.Inventor: Jeffrey H. Yen
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Patent number: 5338444Abstract: Process for removing mercury from an organic medium which at least contains mercury and arsenic, wherein the organic medium is contacted with a solid polymeric substrate containing thiol groups bound to the polymeric substrate through aliphatic groups.Type: GrantFiled: December 9, 1992Date of Patent: August 16, 1994Assignee: The Dow Chemical CompanyInventors: Frederik R. van Buren, Leendert Deij, Gunnar Merz, Hans P. Schneider
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Patent number: 5336396Abstract: A fuel management system for blending of an alternative fuel such as waste oil with a conventional fuel and the continuous filtration thereof before delivery to fuel injection system of a conventional diesel engine. The system attaches to the storage tanks of a heavy duty truck using a proportioning device for withdrawing of the fuels from their respective tanks before blending by use of an air operated diaphragm transfer pump. The blended fuel is continuously recirculated through at least one fiberglass filter with a device for metering the final flow to the injection system and the remainder to the storage tanks. The system can remove up to 99.5 percent of the heavy contaminants found in the diesel fuel and alternative fuels.Type: GrantFiled: March 29, 1993Date of Patent: August 9, 1994Inventor: Michael C. Shetley
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Patent number: 5336415Abstract: A process for the removal of soluble polyvalent metal impurities from aqueous streams, the polyvalent metal selected from groups IIIA, IIIB, IVA, IVB, VA, VB, VIB, VIIB, and VIII in the periodic table of elements, is disclosed. The process comprises, in order:(1) dissolving (a) chitosan or a water soluble salt thereof and (b) a halogenating agent capable of converting chitosan to an N-halochitosan in an aqueous stream that (i) contains said polyvalent metal impurity as a cationic or complex anionic moiety and (ii) is at a pH of 2 to 5.5, wherein an effective amount of N-halochitosan is formed in said aqueous stream to remove said polyvalent metal impurity;(2) raising the pH of the aqueous stream to a pH greater than 6, the pH being sufficiently high to form an insoluble product containing the polyvalent metal impurity and said N-halochitosan; and(3) separating the insoluble product from the aqueous stream.Type: GrantFiled: February 10, 1993Date of Patent: August 9, 1994Assignee: Vanson L.P.Inventor: John R. Deans
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Patent number: 5332509Abstract: A chemical process for selectively removing organometallic compounds from water supplies. The process utilizes a combination of a transition metal selected from the group consisting of nickel, copper, iron and zinc, and an electropositive metal selected from the group consisting of magnesium and aluminum to effectively remove organometallic compounds from water whether present in ionic or non-ionic form.Type: GrantFiled: February 24, 1993Date of Patent: July 26, 1994Assignee: The United States of America as represented by the Secretary of the InteriorInventor: Andrew P. Murphy