Of Separated Solids Patents (Class 210/713)
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Patent number: 6126840Abstract: Process and apparatus for treating an aqueous effluent with high concentrations of silver and ferric/ferrous complexes using multiple additions of one or more water-soluble sulfur containing polymer chelating agents, with optional additions of non-polymeric sulfur containing compounds. The presence of a high concentration of both dissolved silver and ferric/ferrous complexes prevents efficient silver removal by precipitation and the achievement of a very low residual silver concentration. By using multiple additions of the chelating agent(s), a higher degree of silver removal can be achieved than would be possible with the same amount of chelating agents added in a single stage. Effluent from photo finishing operations, particularly minilabs, can be effectively treated so that there is essentially no silver remaining in the treated effluent.Type: GrantFiled: August 13, 1998Date of Patent: October 3, 2000Assignee: Fuji Hunt Photographic Chemicals, Inc.Inventors: Hailing Duan, William Lovell
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Patent number: 6106726Abstract: A method of treatment of an arsenic sludge obtained from a solid-liquid separation step on arsenic waste water by adjusting the value of pH to 12 or higher by adding a calcium compound is disclosed. The method is characterized by addition of hydrated lime and calcining the sludge.Type: GrantFiled: April 24, 1998Date of Patent: August 22, 2000Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Hiroshi Fujita, Koosoo Tao, Taku Shimizu, Mamoru Yokose
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Patent number: 6096222Abstract: An apparatus and method for removing hydrocarbon contaminants and heavy metal ion contaminants from wastewater stream comprising the introduction of iron ions into the stream. In one embodiment, the ions are introduced by applying an electrical current through a bed of iron particulates in the form of steel wool and iron nodules. In another embodiment, the iron salts are added to the waste stream and the iron ions are reduced to a more reactive lower valence state by electric current.Type: GrantFiled: February 24, 1999Date of Patent: August 1, 2000Inventors: Stephen R. Wurzburger, James Michael Overton
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Patent number: 6010631Abstract: In a method of treating an untreated flow of liquid charged with particles and/or colloids, the flow is caused to flow in a coagulation zone that is kept turbulent and in which the flow is mixed with a coagulant. The untreated flow and a granular material which is insoluble in and more dense than the flow are caused to flow in an intermediate zone in which the granular material is maintained in suspension. The flow with substantially all of the added granular material and the colloids or particles aggregated therein is caused to flow in a sedimentation zone in which a clarified effluent is separated from sludge consisting of the granular material and the aggregated particles or colloids. The sedimentation zone has an undivided flow cross section, with no separator plates and the effluent is caused to flow therein at an average settling speed of at least 15 m/h.Type: GrantFiled: November 20, 1998Date of Patent: January 4, 2000Assignee: Omnium de Traitement et de Valorisation (OTV)Inventors: Francoise Delsalle, Nicolas Lepoder, Patrick Binot
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Patent number: 5993668Abstract: Metal ions and/or complexes of metal ions are removed from a solution by formation of an insoluble chelated complex of the metal ions and a polymeric precipitating agent. A two-step process of mixing the influent with the precipitating agent is used to induce rapid precipitation and obtain large, self-agglomerated precipitate without addition of flocculating agent and/or pH adjustment. In addition, parallel loops are employed to simultaneously discharge treated metal-free solution and effectively collect/remove the precipitate-containing sludge without interfering with each other. The metal capturing capacity of the polymeric precipitant is maximized by forcing the influent solution through layers of the collected precipitate and by recycling unsaturated metal-precipitant complexes in the processing loop.Type: GrantFiled: August 28, 1997Date of Patent: November 30, 1999Assignee: Fuji Hunt Photographic Chemicals, Inc.Inventor: Hailing Duan
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Patent number: 5976383Abstract: Aluminum particles are reacted with heavy metal ions in a first acidic aqueous solution to form heavy metallic particles that are suitable for recycling and reuse when recovered from the first aqueous solution. The first residual aqueous solution may also contains ferrous ions obtained by acid redissolving a co-precipitated heavy metal hydroxide and ferrous hydroxide sludge that is produced in the treatment of a dilute chelated heavy metal solution. The first residual aqueous solution with heavy metals substantially removed is recycled and reused as the ferrous reagent for treating said dilute chelated heavy metal bearing solution. The process disclosed herein is useful for treating both dilute and concentrated wastes and wastewaters generated by industries such as metal plating and metal etching and printed circuit board fabrication.Type: GrantFiled: August 12, 1996Date of Patent: November 2, 1999Assignee: Romar Technologies, Inc.Inventors: Robert G Guess, Stephen E. Lavalley
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Patent number: 5962749Abstract: This invention relates to a process for the purification of polyether polyols. This process enables the removal of residual alkaline metal catalyst from produced polyether polyol. It comprises a) adding glycerine to a polyether polyol that contains Group IA alkaline metal catalyst to form a precipitate, and b) separating the precipitate formed in a) to provide a purified polyether polyol. The present invention also relates to the purified polyether polyol produced by this process, the precipitate produced by this process, and the use of the precipitate as an alkaline metal catalyst in a process for the production of polyether polyols.Type: GrantFiled: December 24, 1997Date of Patent: October 5, 1999Assignee: Bayer CorporationInventors: Harold R. Parsons, Donald C. Dunham, Steven L. Schilling, Keith J. Headley
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Patent number: 5914040Abstract: The present invention relates to a process for the purification of a medium containing organic waste. The process according to the present invention is characterized in that the starting medium (or effluent) containing the organic waste is subjected to the following stages: (i) treatment with at least one oxidizing agent; (ii) treatment with at least one flocculating agent; (iii) treatment with at least one polyelectrolyte, and in that the effluent obtained on conclusion of all of these stages is subjected to a filtration stage (iv), whereby a filtration cake and a filtrate are obtained. The process according to the present invention is more particularly useful for the treatment of pig manure.Type: GrantFiled: October 14, 1997Date of Patent: June 22, 1999Assignee: Rhone-Poulenc ChimieInventors: Yvette Pescher, Jean-Paul Raes, Sylvain Danda, Bernard Castelas, Fran.cedilla.ois Rabatel, Jose Morales, Jean Bonfill
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Patent number: 5888404Abstract: The invention relates to a method for treating waste water sludge comprising at least one metal originating from a waste water treatment coagulant, and phosphorus and heavy metals in order to recover said at least one metal and phosphorus and to discharge said heavy metals. In this method said waste water sludge is acidified to dissolve metals contained in the sludge thereby yielding an acidified sludge solution containing at least 1% by weight of at least one metal to be recovered. In a first precipitation stage the pH of said acidified sludge solution is raised to precipitate at least one metal to be recovered as a phosphate, and thereafter the phosphate precipitate is separated, thereby leaving a solution comprising heavy metals. In a second precipitation stage the pH of said solution comprising heavy metals is raised and, if necessary, an appropriate chemical is added to precipitate heavy metals, and thereafter the precipitate is discharged.Type: GrantFiled: August 18, 1997Date of Patent: March 30, 1999Assignee: Kemira Kemi AbInventor: Simo Jokinen
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Patent number: 5855793Abstract: The invention relates to the treatment of waste water containing a harmful ion such as a heavy metal ion or fluorine ion by the coagulating sedimentation method using an inorganic coagulant such as an iron compound or an aluminum compound. After separating treated water from the sediment (sludge) in which the harmful ion is incorporated in insoluble form, the pH of a mixture of the sediment and water is suitably adjusted to cause elution of the harmful ion from the sediment. Then the sediment is separated from the eluate and reused as an inorganic coagulant. By reusing the sediment in this manner, the waste water treatment is accomplished without producing a large quantity of sludge and the consumption of inorganic coagulant and auxiliary chemicals can be greatly reduced, while the concentration of the harmful ion in the treated water becomes sufficiently low.Type: GrantFiled: November 18, 1997Date of Patent: January 5, 1999Assignee: NEC CorporationInventors: Kenichi Ikeda, Yuichi Asai, Yuji Arai
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Patent number: 5849191Abstract: A wastewater treatment method involving mixing of the wastewater with an activated sludge and water that has been supersaturated with air under high pressure is described. After the pressure is reduced two processes are carried out which are biological oxidation of pollutants by activated sludge and flotation of suspended solids. A portion of the treated water is saturated with air and returned to the beginning of the process. The waste activated sludge is removed along with some floated and biologically non-oxidated pollutant particles.Type: GrantFiled: November 22, 1995Date of Patent: December 15, 1998Assignee: Research and Development Company Bifar (RU/RU)Inventors: Robert Yakovlevich Agranonik, Gennady Alexeevich Pisklov
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Patent number: 5843315Abstract: Provided is a novel method and system for recovering aggregate fine size particles from a carrying medium. The method comprises:(a) introducing a feed containing particles to a sand screw, and separating the particles into separate groups of large and fine particles, the fine particles being present in a fine particle stream;(b) introducing the fine particle stream from the sand screw to one or more hydraulic centrifugal separators which overflow a fine particle stream and discharge a coarse particle stream;(c) introducing the overflow fine particle stream from the one or more hydraulic centrifugal separators to a thickening tank and removing precipitated material as an underflow stream from a lower portion of the thickening tank; and(d) introducing the underflow from the thickening tank to a filtering unit.Type: GrantFiled: May 10, 1996Date of Patent: December 1, 1998Assignee: Vulcan Materials CompanyInventors: Bruce E. Baughn, Dennis M. McClelland
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Patent number: 5840195Abstract: In a method of treating an untreated flow of liquid charged with particles and/or colloids, the flow is caused to flow in a coagulation zone that is kept turbulent and in which the flow is mixed with a coagulant. The untreated flow and a granular material which is insoluble in and more dense than the flow are caused to flow in an intermediate zone in which the granular material is maintained in suspension. The flow with substantially all of the added granular material and the colloids or particles aggregated therein is caused to flow in a sedimentation zone in which a clarified effluent is separated from sludge consisting of the granular material and the aggregated particles or colloids. The sedimentation zone has an undivided flow cross section, with no separator plates and the effluent is caused to flow therein at an average settling speed of at least 15 m/h.Type: GrantFiled: March 4, 1997Date of Patent: November 24, 1998Assignee: Omnium de Traitement et de ValorisationInventors: Francoise Delsalle, Nicholas Lepoder, Patrick Binot
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Patent number: 5840194Abstract: The present invention provides a process for treating arsenic-containing waste water, comprising adding an oxidizing agent, if necessary, to arsenic-containing waste water to oxidize trivalent arsenic in the waste water into pentavalent arsenic; adding a calcium compound to adjust the pH to 12 or higher; separating it into solid and liquid (first solid/liquid separation); calcining the resulting sludge, while adding a ferric salt to the treated solution to adjust the pH to 6-9 after the solid/liquid separation; and separating it into solid and liquid (second solid/liquid separation). According to the present invention, it is possible to remove arsenic from waste water efficiently to yield treated water satisfying various tolerance limits under various regulations, while the arsenic-containing sludge separated from the waste water can become harmless in subsequent continuous steps.Type: GrantFiled: December 9, 1996Date of Patent: November 24, 1998Assignee: Mitsubishi Jukogyo Kabushiki KaishaInventors: Mamoru Yokose, Hiroshi Fujita, Koosoo Tao, Hiroshi Baba, Hideki Kamiyoshi, Ranko Shikai
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Patent number: 5824227Abstract: A process for removing dissolved fluorides from an aqueous stream using at least two reactors wherein the dissolved fluoride containing aqueous feed and an unreacted aluminum containing sludge are combined in the first reactor to give a first reactor admixture after which the first reactor effluent stream is directed to the second reactor and therein combined with fresh alum and fresh sodium aluminate to give a second reactor admixture comprising a reduced fluoride aqueous solution and a partially reacted aluminum containing sludge and thereafter recovering the reduced fluoride aqueous solution and recycling at least a portion of the aluminum containing sludge to the first reactor.Type: GrantFiled: March 19, 1997Date of Patent: October 20, 1998Assignee: WMX Technologies, Inc.Inventors: Daniel A. Cargnel, Mark K. Crescenzi
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Patent number: 5800717Abstract: A sedimentation device for treating water and wastewater utilizing differential sedimentation and recirculation in an internal recirculation reactor with an upflow zone and a downflow zone within a settling tank. Inert particles are added to the internal recirculation reactor to increase the growth rate of forming flocs and increase the differential sedimentation of the flocs in the downflow zone.Type: GrantFiled: October 2, 1996Date of Patent: September 1, 1998Assignee: Microsep International CorporationInventors: Stephen R. Ramsay, Donald G. Nyberg
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Patent number: 5770091Abstract: An untreated flow of waste water is normally introduced into a plain sedimentation unit during plain sedimentation periods to separate it into sand and a flow treated by plain sedimentation. During other periods, for example periods of heavy rain, a coagulating agent, ballast sand and a flocculating agent are introduced. The coagulated flow is passed into a maturation intermediate area and then, with substantially all the sand and colloids of particles attached to it, into the plain sedimentation unit. Here effluent is separated by plain sedimentation and evacuated and sludge made up of the sand and the adhering colloids and particles is extracted and evacuated via an extraction system and the sand outlet channel of the plain sedimentation unit. The sludge is collected, the ballast sand is separated from it to be recycled into the sand injection area and the sludge and excess sand are extracted.Type: GrantFiled: August 27, 1996Date of Patent: June 23, 1998Assignee: Omnium de Traitement et de ValorisationInventors: Patrick Binot, Valery Ursel, Michel Badard
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Patent number: 5750033Abstract: The invention relates to the treatment of waste water containing a harmful ion such as a heavy metal ion or fluorine ion by the coagulating sedimentation method using an inorganic coagulant such as an iron compound or an aluminum compound. After separating treated water from the sediment (sludge) in which the harmful ion is incorporated in insoluble form, the pH of a mixture of the sediment and water is suitably adjusted to cause elution of the harmful ion from the sediment. Then the sediment is separated from the eluate and reused as an inorganic coagulant. By reusing the sediment in this manner, the waste water treatment is accomplished without producing a large quantity of sludge and the consumption of inorganic coagulant and auxiliary chemicals can be greatly reduced, while the concentration of the harmful ion in the treated water becomes sufficiently low.Type: GrantFiled: July 31, 1996Date of Patent: May 12, 1998Assignee: NEC CorporationInventors: Kenichi Ikeda, Yuichi Asai, Yuji Arai
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Patent number: 5618439Abstract: A method for purifying aqueous solutions having varying concentrations of contaminants and/or various contaminants including ions of several metals and elements by conducting precipitation in a first precipitation stage by adding lime in a surplus quantity whereby a pH of about 12 is established and maintained in the solution and a major part of the contaminant content is precipitated so as to form a solution having a substantially constant composition and to form a precipitate that is isolated and removed together with residual lime. Precipitation is then conducted in a second precipitation stage by adding a reagent for precipitation at a pH in the range of 4-11 wherein residual contaminant in the formed solution from the first precipitation stage is precipitated the precipitate is isolated and returned to the first precipitation stage.Type: GrantFiled: March 24, 1994Date of Patent: April 8, 1997Assignee: Boliden Contech ABInventor: Torkel Allgulin
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Patent number: 5616168Abstract: Impurity streams generated during the metallurgy of copper are hydrometallurgically processed at ambient pressure for recovery of primary values in an energy-efficient manner and with the capture and conversion of metallic impurities to states that are acceptable for disposal into the environment. Hallmark features of the various embodiments of this invention include the water leach of flue dust, a controlled acid leach stage in which metal species are solubilized, the extraction of copper as a sulfide, and the ability to operate the various process stages at essentially ambient pressure.Type: GrantFiled: March 24, 1995Date of Patent: April 1, 1997Assignee: Kennecott Utah Copper CorporationInventors: Philip J. Gabb, J. Philip Evans
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Patent number: 5575922Abstract: A method for treating mine water from an underground trona ore mine comprising pumping the mine water from the mine, introducing caustic soda into the mine water, maintaining the pH of the treated mine water to between about 11.5 and about 14, separating the treated mine water and introducing the treated mine water into an alkali production process.Type: GrantFiled: June 30, 1995Date of Patent: November 19, 1996Assignee: Solvay Minerals, Inc.Inventors: Kevin L. Green, Robert N. Skogley
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Patent number: 5545331Abstract: Heavy metal ions react with iron particles in acidic aqueous solution to form heavy metallic particles that are suitable for recycling and reuse when recovered from the aqueous solution. Chelating agents that are present are deactivated by bonding to ferrous ions produced from the iron particles. An alkali metal hydroxide is utilized to precipitate remaining heavy metal ions including ferrous and ferric ions which are recycled to the acidic aqueous solution.Type: GrantFiled: February 10, 1995Date of Patent: August 13, 1996Assignee: Romar Technologies, Inc.Inventor: Robert G. Guess
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Patent number: 5538636Abstract: A process to purify waste waters using chemical oxidation and Fenton's reagent by the action in the acid range of hydrogen peroxide and iron(II) compounds and subsequent precipitation in the weakly acid to alkaline range of the iron(III) compounds, said process being characterized in that the sludge containing iron(III) accumulating in addition to the purified waste water is reduced electrolytically back into iron(II) compounds and in that the sludge so reduced is fed back into the process. The process of the invention allows extensive purification of highly concentrated waste waters and furthermore problems arising with the treatment and elimination of the Fenton sludge can be circumvented.Type: GrantFiled: April 14, 1994Date of Patent: July 23, 1996Assignee: Solvay Interox GmbHInventors: Michael Gnann, Carl-Heinz Gregor, Siegfried Schelle
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Patent number: 5518633Abstract: Process for treating aqueous media containing metal ions having valences of +2 and higher and optionally acid comprising:(a) contacting the aqueous media, at a pH of about 1-5, with an effective amount of product recycled from step (b) to dissolve at least some metal carbonates, produce at least some CO.sub.2, convert at least some metal ions having a valence of at least +3 to metal hydroxide precipitates, and neutralize some acid, if present;(b) contacting the product of step (a), at a pH of about 4-8.5, with an effective amount of Na.sub.2 CO.sub.3 to convert at least some metal ions of +2 valence to metal carbonate precipitates and form at least some dissolved sodium salts;(c) recovering, from a portion of the product from step (b) that is not recycled, metal carbonates, metal hydroxides, and sodium salts.Type: GrantFiled: October 21, 1994Date of Patent: May 21, 1996Assignee: E. I. Du Pont de Nemours and CompanyInventors: Cary V. Brown, John S. Craven, Gregory A. Martz, James E. Merkle, Jr., William L. Vick, Melissa C. Wagner
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Patent number: 5507954Abstract: A process for separating grease and solid materials from a waste material so as to produce an aqueous discharge liquid. Waste material containing grease, water and solid materials is passed into a screen tank where course solid materials are separated out of the waste material. The filtrate is accumulated and injected into a series of filters wherein each filter is finer than the previous filter. The filtrate is then agitated to produce a foamed liquid which is substantially separated into a foamed oil portion and an aqueous liquid portion. The aqueous liquid portion is separated from the foamed oil portion and discharged into a sewage system. The solids captured during the filtering process are collected and in turn dried to produce a dried material which can be ground and mixed with other products and processed into animal feed, pesticides or the like.Type: GrantFiled: February 28, 1994Date of Patent: April 16, 1996Inventor: Danny Carrillo
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Patent number: 5462669Abstract: A method and apparatus for dissolved air floatation (DAF) and for gas-liquid contacting operations by dissolved air floatation. A number of involute flow channels in a container have inlets and outlets positioned at either end for involutional or evolutional flow of a mixture of liquid and dissolved gas. Liquid turbulence and mixing are prevented in order to achieve a near plug-flow condition for maximum separation. Other uses of the method and apparatus include hydraulic flocculation of suspended matters in a liquid, separation of non-floatable suspended matters, oxidation of dissolved organic matter, activated sludge processes, purification of water using a biocide, separation by absorption of gases, stripping by desorption of dissolved gases, and gas-liquid reactions.Type: GrantFiled: July 27, 1994Date of Patent: October 31, 1995Inventor: George C. Yeh
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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: 5460730Abstract: Lead oxide is used for neutralizing the sulfuric acid wastewater received from washing charged (formed) electrodes during lead battery production. The neutralization product, including lead sulfate and excess lead oxide, is returned directly to production of the active mass paste. The mother liquor, after a possible use as cleaning water, is subjected to another neutralization with lead oxide, separate from the wastewater received from the electrode washing procedure in view of its possible content of impurities. The resulting lead sulfate is sent to a metal-processing facility for recycling. The neutral mother liquor, after the removal of lead residues by conventional precipitation methods and filtration, is discharged as treated water.Type: GrantFiled: June 27, 1994Date of Patent: October 24, 1995Assignee: Varta Batterie AktiengesellschaftInventors: Thomas Czerny, Rainer Jostes
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Patent number: 5443730Abstract: The invention relates to a process for the purification of a polluted aqueous effluent to obtain an overall reduction in its chemical oxygen demand. The aqueous effluent is introduced into a reactor. Added to the reactor is a reagent comprising an agent supplying active alumina and lime. The reaction forms mineral sludge and an effluent. The mineral sludge and supernatant effluent are then extracted by decantation or filtration.Type: GrantFiled: July 7, 1993Date of Patent: August 22, 1995Assignee: Lafarge Fondu InternationalInventors: Jean-Pierre Letourneux, Alain Bourdeau
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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: 5409614Abstract: NORMs are inhibited or prevented from precipitating with scale produced by a hot aqueous solution by adding multiple portions of a crystal structure modifier to the aqueous solution as it cools before and during removal of silicon containing components by precipitation. Preferred crystal structure modifiers include polyacrylate crystal structure modifiers and phosphonomethylated amines.Type: GrantFiled: July 16, 1993Date of Patent: April 25, 1995Assignee: Union Oil Company of CaliforniaInventors: Darrell L. Gallup, John L. Featherstone
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Patent number: 5403495Abstract: A method for removing dissolved fluoride from waste water involving a multiple stage process which includes a first step of contacting a solution comprising calcium fluoride with a calcium ion source to form a first precipitate and a second step of contacting the first precipitate comprising the calcium ion source with the fluoride-containing waste water solution to form a second precipitate. A first portion of the solution that has been treated directly with the waste water and which contains the second precipitate, is preferably recycled, along with calcium fluoride, to the first step for contact with the calcium ion source. A second portion of the solution treated with the waste water may be transported to a thickener or gravity settling step, and/or to a solids-dewatering step wherein standard filtration equipment may be used to produce a filter cake having a controlled particle size distribution.Type: GrantFiled: October 14, 1993Date of Patent: April 4, 1995Assignee: Tetra Technologies, Inc.Inventors: Roger N. Kust, Surendra K. Mishra, James B. Pfeiffer
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Patent number: 5332508Abstract: A cyclic photocatalytic process for treating waste water containing metal and organic contaminants. In one embodiment of the method, metal ions are photoreduced onto the photocatalyst and the metal concentrated by resolubilization in a smaller volume. In another embodiment of the method, contaminant organics are first oxidized, then metal ions removed by photoreductive deposition. The present invention allows the photocatalyst to be recycled until nearly complete removal of metal ions and organic contaminants is achieved.Type: GrantFiled: September 20, 1993Date of Patent: July 26, 1994Assignee: Regents of the University of ColoradoInventors: Nancy S. Foster, Carl A. Koval, Richard D. Noble
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Patent number: 5330655Abstract: The invention is directed to a method of regulating a flotation system having an inflow quantity of suspension flow dependent on production demands, including a primary flotation stage and a secondary flotation stage where the secondary flotation stage treats the froth of the primary stage, transporting de-aereated froth from the primary flotation stage to a collection vessel which is in fluid communication the secondary flotation stage; recycling suspension flow from the secondary flotation cells of the secondary flotation stage in part to an inlet of the primary flotation stage, and in part to an inlet of the secondary flotation stage, and regulating the level of de-aereated froth in the collection vessel by controlling the amount of suspension flow recycled from said secondary flotation stage to the inlet of the secondary flotation stage.Type: GrantFiled: July 30, 1993Date of Patent: July 19, 1994Assignee: J.M. Voith GmbHInventors: Peter Schweiss, Hans-Dieter Dorflinger
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Patent number: 5298169Abstract: Disclosed is a process for treating waste sulfuric acid generated from a process for producing titanium dioxide pigment by treating titanium slag with sulfuric acid. The waste acid is treated in a first step with a calcium-containing material to produce a gypsum suspension which is filtered and from which a filtrate is recovered. The filtrate is treated in a second step with a calcium-containing substance and clarification solids from the treatment of the titanium slag with sulfuric acid. A precipitate is produced in this second step which is subsequently filtered. The precipitate is suitable for disposal in a landfill.Type: GrantFiled: August 21, 1992Date of Patent: March 29, 1994Assignee: Kronos, Inc.Inventors: Roger Laferriere, Pierre Beaupre
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Patent number: 5298168Abstract: A process for removing dissolved heavy metal from an aqueous solution is provided where 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 the heavy metal. Solution from the first step is reacted in a second step with hydroxide slurrys obtained from third and fourth steps. A second solution from the second step is reacted in a third step with an alkali composition and a third solution. 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 is disposed of.Type: GrantFiled: June 3, 1992Date of Patent: March 29, 1994Assignee: Romar Technologies, Inc.Inventor: Robert G. Guess
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Patent number: 5290454Abstract: A process is for removal of suspended solids including resin and fatty acids from pulp mill effluents including Chemi-Thermo-Mechanical Pulp (CTMP) mill effluents. The process involves filtration of untreated or primary treated effluents through a mat of primary sludge, pulp or woodroom sludge. A sludge mat is formed on a wire screen or punched drum and the effluent to be treated is filtered through the mat. Most of the suspended solids and a part of colloidal material and dissolved solids are retained by the mat. Following the filtration stage, the sludge is dewatered and removed. A portion of the sludge is recycled to form the mat for the next filtration cycle, while the excess sludge is purged. The filtration is achieved by the application of vacuum below the filter mat or pressure over mat.Type: GrantFiled: November 12, 1992Date of Patent: March 1, 1994Assignee: Pump and Paper Research Institute of CanadaInventors: Joseph Dorica, Steven Prahacs, Pritham Ramamurthy
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Patent number: 5288411Abstract: Radioactivity and fluoride ion are inhibited or prevented from precipitating in scale formed from a geothermal brine by adding a scale inhibitor to the cooling brine solution. Preferred scale inhibitors include polyacrylate dispersants and phosphonomethylated amines.Type: GrantFiled: March 31, 1992Date of Patent: February 22, 1994Assignee: Union Oil Company of CaliforniaInventors: Darrell L. Gallup, John L. Featherstone
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Patent number: 5280701Abstract: The invention comprises an apparatus and method for high pressure treatment of wastes without the addition of excess oxygen and without interference by corrosive deposits. Waste materials are suspended or dissolved in a processing fluid. The pressure of the fluid is raised to a pressure in the range of from about 70 psig to about 5,000 psig. A boiler is then used to heat the high pressure fluid to temperatures above the critical temperature. Solids within the boiler participate in fluidized bed particle scrubbing technology in order to minimize the fouling and corrosion occurring within the boilers during heating. From at least a portion of the vapors produced by the heating in the boiler, net energy output is produced. Useful byproducts can be produced from the vapors.Type: GrantFiled: August 31, 1992Date of Patent: January 25, 1994Assignee: Environmental Energy Systems, Inc.Inventor: Radon Tolman
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Patent number: 5268108Abstract: Radioactivity and fluoride ion are inhibited or prevented from precipitating in scale formed from a geothermal brine by adding a dispersant to the cooling brine solution. Preferred dispersants include polyacrylates and polyphosphonic acids.Type: GrantFiled: June 19, 1991Date of Patent: December 7, 1993Assignee: Union Oil Company of CaliforniaInventors: Darrell L. Gallup, John L. Featherstone
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Patent number: 5248416Abstract: A sewage treatment system which presents a main flow line and a recirculating line, the former for flock which has appreciated in size due to the addition of a polymer and passage through an area of agitation/turbulence and the latter for the return of small sized flock to the agitator/turbulence area for size increase. The passageways of the system include movable flaps, serving recirculation purposes, and a ledge or flutter for current creation and flock build-up. Raw liquid sewage enters the system, where the outlet leads to a belt press and/or a dry bed to cake the resulting sludge.Type: GrantFiled: November 18, 1991Date of Patent: September 28, 1993Inventor: Ronnie E. Howard, Jr.
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Patent number: 5246593Abstract: The concentration of amorphous silica in an aqueous solution is monitored to determine a concentration above which silica will precipitate. The precipitation concentration is data processed with a means for data processing by solving the Setchnow equation for aqueous solutions containing silica. The means for data processing generates a signal that, if need be, can be used to automatically adjust the parameters of the system to prevent silica precipitation or to carefully control the precipitation rate. An alternative embodiment provides a method for determining amorphous silica concentration, then data processing the solution to the Setchnow equation, generating a signal, and adjusting the parameters of the system. The apparatus and method of this invention are particularly useful in geothermal power plants.Type: GrantFiled: October 31, 1991Date of Patent: September 21, 1993Assignee: Union Oil Company of CaliforniaInventor: Darrell L. Gallup
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Patent number: 5242601Abstract: A process for treating contaminated sludges such as municipal sewage sludge, industrial waste sludge and riverbottom sludge with calcium oxide (CaO) and/or calcium carbide (CaC.sub.2) with reclaiming and recycling of calcium oxide (CaO) from the reaction materials. The process is also applicable for dechlorinating PCB contaminated sludges.Type: GrantFiled: June 6, 1991Date of Patent: September 7, 1993Assignee: Alternative Technologies For Waste, Inc.Inventors: Frank Manchak, Jr., Frank Manchak, III, Peter Manchak
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Patent number: 5242600Abstract: A wastewater flotation separation system is provided, which operates effectively with a minimum of maintenance. The apparatus includes a container (12) for holding wastewater, an inlet (14) located at a lower portion of the container, and an aerator (24) adjacent to the inlet for generating air bubbles that cling to waste particles to bring them to the water surface. A skimming apparatus (30) which skims particles off the surface of the wastewater into a sludge receiver (44) includes a beach device (42) with an inclined upper surface (40), and a belt device (34) that moves a series of scrapers (32) along the surface of the water and along the beach device into the sludge discharge. Each scraper includes a flap of resilient material which is bent as it scrapes along the inclined beach surface.Type: GrantFiled: December 19, 1991Date of Patent: September 7, 1993Inventors: Donald M. Meylor, Patrick J. Finn
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Patent number: 5227073Abstract: In a method of dewatering suspensions or the like slurry-like mixtures, in particular waste water slurries, fed to a belt filter press formed by filter belts, with the waste water slurry, is a crumbly dry substance which has been produced by drying from the solids discharge of the belt filter press.Type: GrantFiled: October 15, 1991Date of Patent: July 13, 1993Assignee: Alb. Klein GmbH & Co. KGInventors: Wendel Bastgen, Otto Klein, deceased
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Patent number: 5225087Abstract: A process for recovering the chelating or complexing agents, particularly ethylenediaminetetraacetic (EDTA), used in chemical cleaning and decontamination operations performed to clean steam generators, especially nuclear powered steam generators, is provided. The EDTA, metal and radionuclide-containing aqueous waste stream is, optionally, first treated to remove the metals and radionuclides. The pH of the resulting liquor is then adjusted to less than 2.0, causing the precipitation of acid EDTA. The solid acid EDTA is recovered for reuse or disposal, as desired. The remaining liquid is treated as required to permit environmental disposal. Removal of the metals and radionuclides can be by sulfide precipitation or ion exchange and may be conducted before or after precipitation of the acid EDTA.Type: GrantFiled: May 10, 1991Date of Patent: July 6, 1993Assignee: Westinghouse Electric Corp.Inventor: Zoltan L. Kardos
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Patent number: 5211853Abstract: A process for precipitating and removing chromium compounds in which chromium is in the hexavalent state from aqueous liquids, particularly, alkaline earth metal or alkali metal chlorate-rich solutions containing chloride, chlorate, and bichromate ions produced by the electrolysis of brine. In the process, hydroxylamine, hydroxylamine sulfate, hydroxylamine formate or hydroxylamine hydrochloride is used as a reducing agent to react and co-precipitate at a neutral or acid pH with hexavalent chromium ions present in the aqueous liquid, the reaction and precipitation taking place, generally, at a pH of about 4.0 to about 6.5 and, a temperature of about 50.degree. C. to about 100.degree. C. Precipitated oxides and hydroxides of divalent and trivalent chromium can be removed, for instance, by filtration.Type: GrantFiled: July 31, 1992Date of Patent: May 18, 1993Assignee: Huron Tech Corp.Inventors: John R. Jackson, Charles L. Pitzer
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Patent number: 5167821Abstract: A method for efficiently thickening and dewatering a slurry sludge in a short period of time without the necessity of a vast site, which comprises the steps of: stirring a slurry sludge added with a coagulant in a stirring tank to convert the slurry sludge into a floc; supplying the floc and a superantant liquid, which are produced in the stirring tank, onto an inlet side of an inclined endless travelling filter cloth of an endless travelling filter cloth type dewatering unit, which comprises a dewatering tank and the above-mentioned inclined endless travelling filter cloth arranged in the dewatering tank; continuously travelling the thus supplied floc, on the endless travelling filter cloth, toward an exit side thereof; thickening the floc on a portion of the endless travelling filter cloth, which portion is located in the supernatant liquid in the dewatering tank, and dewatering the thus thickened floc on a portion of the endless travelling filter cloth, which portion is located above the surface of the supType: GrantFiled: January 29, 1991Date of Patent: December 1, 1992Assignees: Norihito Tambo, NKK CorporationInventors: Norihito Tanbo, Hiromu Fukano, Yasuhiko Kihara
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Patent number: 5158686Abstract: A process and associated apparatus for removing contaminants such as heavy metals from contaminated water, waste water, sludge or flushed soil elutriates, or leachates. The remediation method utilizes a combination of chemical oxidation/reduction reactions and physical separation techniques employing a pseudofluidized bed and is carried out in a unitary reactor comprising zones for activation, flocculation and phase separation.Type: GrantFiled: February 25, 1991Date of Patent: October 27, 1992Assignee: Envar Services, Inc.Inventor: Mark Y. Kigel
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Patent number: RE36915Abstract: A process for treating industrial waste water containing hexavalent chromium (Cr.sup.+6) and other heavy metals is disclosed which comprises reduction of Cr.sup.+6 to trivalent chromium (Cr.sup.+3) and the precipitation thereof with other heavy metals by addition of sulfide ion and ferrous ion to the waste stream at a pH of about 7 to 9 under conditions such that sludge production by the process of the invention is substantially less than that characteristic of prior art processes. Polymers are added to the solution to assist flocculation and clarification of the waste stream. More specifically, the invention comprises adding sulfide ion in a sulfide to hexavalent chromium ratio of about 0.7-2.5:1 and adding ferrous ion in a ferrous to hexavalent chromium ratio of about 0.5-5.0:1. The waste stream pH is preferably maintained in the range of about 7.2 to 7.5.Type: GrantFiled: March 17, 1993Date of Patent: October 17, 2000Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Dan F. Suciu, Penny M. Wikoff, John M. Beller, Charles J. Carpenter