Digesting Sludge Patents (Class 210/613)
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Patent number: 6299775Abstract: A waste and wastewater treatment and recycling system separates blackwater and greywater at their respective sources and includes a waste separation system for decomposing the blackwater into water vapor and carbon dioxide gas, a wastewater treatment system for circulating, aerating, and separating the greywater into precipitated solid matter and treated water, and a filtration, disinfection, and water recycling system for filtering and disinfecting the treated water to form recyclable water. The precipitated solid matter is transferred to the waste separation system and the recyclable water is passed through a membrane filtration system to form potable water. A monitoring system monitors and controls operation of the waste separation system, the wastewater treatment system, and the filtration, disinfection, and water recycling system.Type: GrantFiled: March 17, 2000Date of Patent: October 9, 2001Inventor: Clint R. Elston
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Patent number: 6296766Abstract: A method for an anaerobic digester system is provided that employs a cumulative data base to better monitor and control the anaerobic process, as compared with conventional anaerobic digester systems. The method includes the storing and ensiling of a feedstock, preferably a biomass, to form a digester feed material, which then processed by a digester. The process evolves a biogas and forms a digested material. The process is monitored, to collect a plurality of digester data from all stages of the process. These individual points or elements of the data are telemetered to a cumulative data base for storage and eventual retrieval and the cumulative data base is mined to compile predictive, feed forward controls and construct feedstock correlations between the metabolic activity within the digesters and an analysis of the feedstocks into the digesters. The method further includes the production of a high quality plant growth media from the digested mash, and recovery of the biogas generated within the digester.Type: GrantFiled: November 12, 1999Date of Patent: October 2, 2001Inventor: Leon Breckenridge
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Patent number: 6281001Abstract: The invention includes a method and apparatus for composting organic material and maintaining composting conditions within preselected limits. Composting according to the method can occur within a sealable container. Adjusting the composition of the organic material to within preselected limits converts the organic material to a compostable mixture. The composition is adjusted by amending the organic material and by mixing the amended organic material with a bulking agent and an inoculant. Incubating forms a composting mixture from the compostable mixture. The method includes the steps of monitoring and adjusting conditions of the composting mixture to maintain the conditions within preselected limits. The conditions of the composting mixture are adjusted by aerating the composting mixture or remixing the composting mixture. The remixed composting mixture is incubated to yield composted organic material.Type: GrantFiled: November 2, 1998Date of Patent: August 28, 2001Inventor: James J. McNelly
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Publication number: 20010001454Abstract: The invention relates generally to a process and apparatus for treating biosolids resulting from the treatment of biological wastewater streams. The invention relates to autothermal aerobic treatment of biosolids where temperature is controlled by adjusting the amount of shear generated through jet aeration devices. The invention provides for a truly aerobic environment under which thermophilic microorganisms will thrive. The invention also relates to a method and apparatus for controlling foam generated in a treatment reactor.Type: ApplicationFiled: December 29, 2000Publication date: May 24, 2001Inventors: Richard L. Pressley, Jeffrey D. Williamson
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Patent number: 6232464Abstract: The invention relates to an apparatus for isolating nucleic acids from biological fluids and suspensions containing nucleic acids, a reaction compartment 17 for receiving an adsorption medium 100 being connected to a removal compartment 50, and the nucleic acids being able to be moved and enriched from the reaction compartment 17 into the removal compartment 50 by an electrophoresis apparatus 20a, 20b.Type: GrantFiled: August 27, 1999Date of Patent: May 15, 2001Inventor: Hans Lange
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Patent number: 6203701Abstract: The invention relates generally to a process and apparatus for treating biosolids resulting from the treatment of biological wastewater streams. The invention relates to autothermal aerobic treatment of biosolids where temperature is controlled by sensing the oxidation/reduction potential of a treated solution and adjusting the amount of oxygen or the amount of biosolids supplied to the solution. The invention provides for a truly aerobic environment under which thermophilic microorganisms will thrive.Type: GrantFiled: July 1, 1999Date of Patent: March 20, 2001Assignee: Thermal Process Systems, LLCInventors: Richard L. Pressley, Jeffrey D. Williamson
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Patent number: 6200475Abstract: A method of converting organic waste to a useful end product by aerobic thermophilic fermentation process within a short period of time, includes the steps of mixing the organic waste that naturally contains microorganisms with the porous material as a fermentation medium in a mixing digester to form a waste mixture, providing an external heat source to transfer heat into the waste mixture of the organic waste and the porous material, maintaining the waste mixture at a thermophilic temperature to create microbial symbiosis and mutualism reaction to proliferate and grow beneficial thermophilic microorganisms between the porous material and microorganisms that naturally present in the organic waste and allowing whereby the microbial reaction to accelerate the organic waste fermentation and decomposition speed and decompose the organic waste into the usefil end product within a short period of time.Type: GrantFiled: September 20, 1999Date of Patent: March 13, 2001Inventor: Shen-Yuan Chen
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Patent number: 6168717Abstract: The invention relates generally to a process and apparatus for treating biosolids resulting from the treatment of biological wastewater streams. The invention relates to autothermal aerobic treatment of biosolids where temperature is controlled by adjusting the amount of shear generated through jet aeration devices. The invention provides for a truly aerobic environment under which thermophilic microorganisms will thrive. The invention also relates to a method and apparatus for controlling foam generated in a treatment reactor.Type: GrantFiled: January 20, 1999Date of Patent: January 2, 2001Assignee: Thermal Process Systems, LLCInventors: Richard L. Pressley, Jeffrey D. Williamson
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Patent number: 6168642Abstract: A recycling process for garbage containing a high proportion of paper where printed paper is first separated from the garbage. The garbage is then into pieces and light and heavy components are separated out in a classification tank. The remaining organic mass suspended in water is hydrolyzed and subjected to anaerobic digestion followed by aerobic co-composting. The resulting solid is a high grade fertilizer while biogas produced by the process is converted to electrical energy in a combined cycle installation.Type: GrantFiled: November 24, 1998Date of Patent: January 2, 2001Assignee: Innoval Management LimitedInventors: George Valkanas, Apostolos G. Vlyssides
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Patent number: 6146896Abstract: A method and apparatus for determining nitrification effectiveness of activated sludge in an aqueous solution, includes supplying equivalent quantities of an activated sludge, an aqueous solution, and a gas containing oxygen to each of first and second reaction vessels; simultaneously delivering a nitrification inhibitor to only the second reaction vessel; performing a bacterial respiration reaction in the vessels for either a preselected period of time or continuously in which case the materials are supplied per unit of time so that the bacterial respiration reaction in the first reaction vessel, where oxygen consumption as a result of total bacterial respiration occurs and includes oxygen consumption as a result of endogenous respiration, oxygen consumption as a result of nitrification, and oxygen consumption as a result of degradation of carbon compounds, may be compared with the respiration reaction in the second reaction vessel where oxygen consumption includes oxygen consumption as a result of endogenouType: GrantFiled: September 19, 1997Date of Patent: November 14, 2000Assignee: LAR Analytik und Umweltmesstechnik GmbHInventor: Ulrich Pilz
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Patent number: 6132614Abstract: A modular system for treating wastewater is designed having different phases. In an initial phase, plural tanks are provided, including at least one reactor and digester tank. In a subsequent phase, at least one of the tanks is converted into a different type of tank, and additional new tanks are provided to accommodate larger quantities of wastewater. In one embodiment, conversion of at least one of the tanks is accomplished by removing a temporary wall from a digester tank to create another reactor tank.Type: GrantFiled: October 8, 1998Date of Patent: October 17, 2000Assignee: Pacific Advanced Civil Engineering, INCInventors: Johan A. Perslow, Mark E. Krebs, James A. Matthews
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Patent number: 6113789Abstract: An anaerobic process for digesting organic waste solids to produce residual solids having low levels of pathogens so as to meet regulatory Class A requirements involves a pasteurization step to reduce pathogen levels and digestion of the pasteurized material to reduce the solids volume.Type: GrantFiled: July 16, 1999Date of Patent: September 5, 2000Assignee: Western Environmental Engineering CompanyInventor: Dennis A. Burke
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Patent number: 6106716Abstract: The invention provides a system 10 for treatment and purification of domestic household effluent, and for the elimination within said system of organic solid wastes, comprising elements 12 and 14 for separately collecting first and second constituents of the sewage of a domestic residential unit, lavatory sewage comprising said first sewage constituent, and bath, shower, wash basin, laundry, kitchen sink sewage and the like comprising said second sewage constituent, a first and a second dual-purpose vessel 22 and 24, each vessel having at least one inlet port 18 and 20 and at least one outlet port 26, 28, 30, 32 and being arranged so that during the time period that one of said vessels 22 receives said first sewage constituent and acts as a collector and settling tank, the remaining vessel 24 operates as an anaerobic reaction vessel, the vessel operating as an anaerobic reaction vessel carrying out a decomposition process during which the volume of sludge 34 contained therein is greatly reduced by conversionType: GrantFiled: September 15, 1999Date of Patent: August 22, 2000Inventor: Eliezer Berkman
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Patent number: 6059972Abstract: A tank (1) for an apparatus for receiving and conditioning organic waste by anaerobic bioconversion, in particular, waste produced by restaurant kitchens and other facilities, includes a main enclosure wherein bioconversion takes place, and a secondary enclosure (18) for receiving and storing ground organic waste before it is transferred to the main enclosure for completion of its bioconversion. A hopper (4) or other device for receiving the organic waste is associated with a grinder (2) and is connected to the secondary enclosure (18) of the tank for feeding the ground organic waste. A recirculation system (12, 15) for recycling the contents of the tank includes a pump (13), means for distributing (17a, 17b) the contents of the main enclosure between the different levels thereof, and separate means (9, 22) for removing solid residues and liquid waste.Type: GrantFiled: August 21, 1998Date of Patent: May 9, 2000Inventor: Fran.cedilla.ois-Regis Mahrer
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Patent number: 6033571Abstract: An activated sludge treatment apparatus having an aeration tank 14 for subjecting an organic waste water to an aerobic biological treatment, a first precipitation device 16 for separating a waste water treated in aeration tank 14 into treated water and a sludge, a recycle route 18 for returning a portion of the sludge separated by precipitation device 16 to aeration tank 14, a solubilizing treatment device 24 for solubilizing, at a high temperature, excess sludge separated by precipitation device 16, and a return route 30 for returning a treated solution solubilized by solubilizing treatment device 24 to aeration tank 14, is disclosed.Type: GrantFiled: January 9, 1998Date of Patent: March 7, 2000Assignee: Shinko Pantec, Co., Ltd.Inventors: Susumu Hasegawa, Masahiko Miura, Kenji Katsura, Hideki Yokoyama, Akihiko Hogetsu
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Patent number: 5972220Abstract: An aerobic treatment process is operated to reduce overall oxygen requirements, to maintain general pH balance and to produce a low-coliform solids effluent. From the system's clarifier a slurry of concentrated solids is moved to a premix basin, where the slurry is vigorously aerated for a sufficient time to raise microbial activity and dissolved oxygen content. The aerated, microbially active sludge is then moved to a gravity thickener basin, in which solids are allowed to settle to the bottom without aeration, to establish a quiescent state in the settled sludge and also an anoxic stage. This causes the sludge to be denitrified by microbial action, raising and stabilizing the pH of the sludge. Separated supernatant liquid is decanted and removed from the gravity thickener. The sludge is moved into an aerobic digester, where the sludge is aerated and nitrification occurs but using less aeration than normally required in a digester, due to the effect of anoxic/aerobic phases.Type: GrantFiled: June 3, 1998Date of Patent: October 26, 1999Assignee: Enviroquip, Inc.Inventor: Elena Bailey
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Patent number: 5954964Abstract: The present invention comprises a wastewater treatment process wherein the waste activated sludge is digested to produce treated biosolids which are then directed to a dewatering facility that removes water from the treated biosolids. Before or during the dewatering process, both a low molecular weight polymer and a high molecular weight polymer are added to the treated biosolids. The addition of the two polymers of different molecular weights results in the treated biosolids coagulating and then forming flocs of biosolids that effectively drives water from the flocs and renders the flocs more susceptible to an efficient and effective dewatering process.Type: GrantFiled: July 29, 1997Date of Patent: September 21, 1999Assignee: Kruger, Inc.Inventors: Bente Elise Nielsen, R. David Holbrook
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Patent number: 5948261Abstract: The invention relates generally to a process and apparatus for treating biosolids resulting from the treatment of biological wastewater streams. The invention relates to autothermal aerobic treatment of biosolids where temperature is controlled by adjusting the amount of shear generated through jet aeration devices. The invention provides for a truly aerobic environment under which thermophilic microorganisms will thrive.Type: GrantFiled: February 5, 1998Date of Patent: September 7, 1999Inventor: Richard L. Pressley
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Patent number: 5942022Abstract: A composting plant and method for composting organic waste such as household waste separated at the source, sludge, wood chippings, straw, farmyard manure. The plant comprises a sealed compartment with an inlet zone with a device for feeding in the waste which is advanced from a receiving and preprocessing plant through an airtight sluice device; a process zone with one or more devices preferably a texturing agitator (14) suspended in a runner (46) for advancing and aerating of the waste from the inlet zone and through the process zone to an outlet zone with devices (18) for discharging the composted waste from the compartment. The bottom of the process zone which is connected to a ventilating equipment (26, 30, 34) is designed in such a manner that an aeration takes place up through the waste heap preferably via a bottom layer of coarse organic material such as wood chippings.Type: GrantFiled: August 8, 1996Date of Patent: August 24, 1999Assignees: Maskinfabriken Samson Tange A/S, Bioplan A/SInventors: Vagn Bislev, Per Thostrup
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Patent number: 5906931Abstract: Method and device for digestion of sludge, sludge being transferred stepwise to closed containers (10A, 10B) and gas generated during the digestion process being transferred from said containers (10A, 10B). The sludge is transferred to a first closed space (11A) in a first container (10A) for a first digestion period, and is then after a predetermined period transferred to a second closed space (11B ) in a second container (10B) for a second digestion period. During said first digestion period as well as during said second digestion period the sludge is repeatedly put into movement by tipping said containers (10A, 10B), the flow direction of said sludge being changed to redirect surface material of the sludge to bottom material by the movement of the sludge. Each of said containers (10A, 10B) is provided with an inlet (12) for sludge and a first outlet (13) for gas generated during the digestion period.Type: GrantFiled: February 10, 1998Date of Patent: May 25, 1999Assignee: Eskil OlssonInventors: Peter Nilsson, Eskil Olsson
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Patent number: 5885950Abstract: A composition and methods for cleaning grease-traps, septic tank control, discharge water from industrial meat and poultry processing and packing plants, lift stations and municipal systems. The composition comprises preservatives at a concentration of about 0.35%, by weight, a non-ionic surfactant at a concentration of about 8%, by weight, triethanolamine at a concentration of about 2%, by weight and a fermentation supernatant at a concentration of about 12.14%, by weight. In a preferred embodiment of the present invention the composition comprises a fermentation supernatant from a Saccharomyces cerevisiae culture, sodium benzoate, imidazolidinyl urea, diazolidinyl urea, triethanolamine and a polyoxyethlene alcohol surfactant.Type: GrantFiled: January 28, 1997Date of Patent: March 23, 1999Assignee: Neozyme International, Inc.Inventors: Parker Dale, John E. Hill
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Patent number: 5863434Abstract: A process to stabilize, deodorize, recover energy, reduce pollution potential, and add value to organic waste such as animal manure is described. The process involves the anaerobic digestion of animal manure at low temperatures in intermittently fed sequencing batch reactors. The process of the present application offers several advantages over the prior art processes including (1) the process works very well at low temperatures and therefore does not require pre-heating of the animal manure; (2) the process does not require continuous or daily feeding nor does it require continuous mixing; (3) the process makes use of existing handling and storage equipment at the farm and requires minimal supervision and skill by the operator; (4) the process is very efficient in retaining the slow growing microorganisms in the system and (5) the system is not affected by high concentrations of volatile acids and ammonia or nitrogen. Consequently, the process is low cost and does not interfere with regular farm operations.Type: GrantFiled: September 27, 1996Date of Patent: January 26, 1999Assignees: University of Ottawa/Universite D'Ottawa, Her Majesty in Right of Canada as Represented by the Minister of Agriculture and Agri-FoodInventors: Daniel I. Masse, Ronald L. Droste
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Patent number: 5853450Abstract: The method of treating wastewater or bioorganic sludges containing odor, animal viruses, pathogenic bacteria, and parasites to produce a bioactive but stabilized product that is useful as a soil substitute or as a fertilizer which can be applied directly to lands which consists essentially of the following steps: mixing said sludge with at least one alkaline material, wherein the amount of added material mixed with said sludge is sufficient to raise the pH of said mixture to pH 12, and raise the conductivity to disinfect and stabilize the sludge, and adding green waste at different process locations so that a biological action occurs converting the greenwaste into a soil-like granular product with improved odor over that of the treated municipal sludge alone or a composted greenwaste alone.Type: GrantFiled: September 3, 1997Date of Patent: December 29, 1998Assignee: Medical College of OhioInventors: Jeffrey C. Burnham, Frederick H. Kurtz
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Patent number: 5846425Abstract: A method for treating wastewater is useful in treatment of biomass (sludge) resulting from wastewater treatment, particularly for biological sludges of aerobic, facultative and/or anaerobic origin. The invention relates fractionation of microorganisms and organic materials within the sludge by mechanical shearing, in combination with heat, chemical and/or biochemical treatment to improve waste treatment and to release nutrients for recirculation for use by microorganisms in the waste treatment system.Type: GrantFiled: January 3, 1996Date of Patent: December 8, 1998Inventor: George R. Whiteman
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Patent number: 5810903Abstract: A thermophilic, aerobic fermentation process is disclosed for conversion of a wide variety of organic waste materials to useful end products. The fermentation process is initiated over a period of from about 2 to 6 days by application of external heat to an uninoculated, oxygenated aqueous mixture of the waste material, and thus utilizes thermophilic microorganisms naturally present in the waste material to initiate the fermentation. After initiation of an active fermentation, additional amounts of waste material are added to the fermenting mixture on a continuous or intermittent basis to maintain the fermentation in an active state. Therefore, the process can be conducted on a continuous or semi-continuous basis, requiring about 24 to 48 hours for waste to be completely converted to end product. The process is capable of being operated over a wide pH range and can ferment acidic waste materials without the need for pH adjustment.Type: GrantFiled: August 26, 1996Date of Patent: September 22, 1998Inventors: Rene Joseph Branconnier, Daniel Brian Cumming, Robert Lester Jackman
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Patent number: 5785852Abstract: A process and apparatus for pretreating microbial sludges in order to enhance secondary anaerobic digestion. The pretreatment process involves disrupting the cellular integrity of municipal sewage sludge through a combination of thermal, explosive decompression and shear forces. The sludge is pressurized and pumped to a pretreatment reactor where it is mixed with steam to heat and soften the sludge. The pressure of the sludge is suddenly reduced and explosive decompression forces are imparted which partially disrupt the cellular integrity of the sludge. Shear forces are then applied to the sludge to further disrupt the cellular integrity of the sludge. Disrupting cellular integrity releases both soluble and insoluble organic constituents and thereby renders municipal sewage sludge more amenable to secondary anaerobic digestion.Type: GrantFiled: April 6, 1995Date of Patent: July 28, 1998Assignee: Midwest Research InstituteInventors: Christopher J. Rivard, Nicholas J. Nagle
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Patent number: 5723048Abstract: A method of anaerobic digestion of sewage sludge including the steps of subjecting surplus sludge to preliminary heat treatment at 60.degree. C. or higher, dewatering the surplus sludge to make dewatered sludge of 10 to 25% by weight, mixing the dewatered sludge with digested sludge which is taken out from a methane fermentation vessel of dewatered sludge, and supplying the resulting mixture to the methane fermentation vessel of dewatered sludge while discarding digested sludge whose amount is equal to that of the dewatered sludge supplied. According to the method, the sewage sludge containing a large quantity of surplus sludge is subjected to preliminary heat treatment, and then the heat-treated sludge is dewatered to permit a nitrogenous component to be transferred to eliminated water whereby the nitrogenous component in the dewatered sludge can be reduced. The resulting dewatered sludge can stably undergo methane fermentation even at a high concentration of 10 to 25% by weight.Type: GrantFiled: June 27, 1996Date of Patent: March 3, 1998Assignee: Hitachi Zosen CorporationInventors: Yoshio Kobayashi, Minoru Akita
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Patent number: 5684053Abstract: A process for recovering paint overspray particles includes segregating the paint overspray by color and type, and detackifying, dewatering, drying and particulizing the dried, dewatered, detackified, segregated paint overspray compounds. The resultant compounds is used as paint additive.Type: GrantFiled: August 31, 1995Date of Patent: November 4, 1997Assignee: Caterpillar Inc.Inventor: John M. Spangler
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Patent number: 5670047Abstract: An anaerobic digestion process capable of converting organic slurries to precipitates, as well as soluble and gaseous products through a series of reactors or process steps. The organic material is processed through three sequential steps consisting of two anaerobic digestion steps and an intermediate liquid/solid separation step. The sequential steps consist of first degrading rapidly metabolized soluble and particulate constituents, contained in the influent, by mixing the influent to the first reactor with an effluent from a second reactor containing a high concentration of active biomass. Effluent from the first reactor is treated in a second step wherein the soluble and particulate components are mechanically separated from an effluent stream essentially free of particulate material but containing soluble products of digestion.Type: GrantFiled: April 15, 1996Date of Patent: September 23, 1997Inventor: Dennis A. Burke
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Patent number: 5651890Abstract: Anaerobic digestion of wastewaters can be made more effective by introducing propane gas from an external source therein in order that the propane gas strips gas produced by the anaerobic digestion (e.g., methane, carbon dioxide, etc.) from the biomass system.Type: GrantFiled: September 13, 1996Date of Patent: July 29, 1997Inventor: Paul B. Trost
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Patent number: 5645725Abstract: A process and a device for biologically treating an organic waste mixture containing organically polluted waste water and solid components. The process and the device involve exposing the organic waste mixture to a first decomposition stage where the solid components and the waste water are separated from one another and where the solid components are decomposed under predominantly aerobic conditions. The waste water is then passed to a second decomposition stage where the waste water is decomposed under anoxic conditions. Thereafter, the waste water is passed to a third decomposition stage where the waste water is decomposed again under aerobic conditions thereby creating recirculation water. At least a portion of the recirculation water is returned from the third decomposition stage to the first decomposition stage for continuously recirculating water through and between respective decomposition stages.Type: GrantFiled: February 8, 1995Date of Patent: July 8, 1997Assignee: Protec Partner Fuer Umwelttechnik GmbHInventors: Dorit Zitzelsberger, Gerd Ahne, Josef Winter, Karl Bleicher
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Patent number: 5635077Abstract: A method for stripping ammonia from a film of digested sludge including flowing alkaline liquid sludge as a film on a tower's interior wall and flowing an ammonia stripping gas past the film creating a vapor containing ammonia and stripping gas; then disengaging the liquid sludge from the vapor in a tower disengaging zone.Type: GrantFiled: June 6, 1995Date of Patent: June 3, 1997Assignee: The Dow Chemical CompanyInventors: Jeffrey H. Stultz, Danford L. Bice
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Patent number: 5591342Abstract: An anaerobic digestion process for the removal of the organic matter contained in a liquid waste, notably raw water, subjects the waste to an acidogenesis stage and then to a methanogenesis stage. The waste, which has been subjected to the acidogenesis stage, is subjected to a stage of separation by settling, before the methanogenesis stage. At least part of the sludge separates during this intermediate stage. Part of the treated water is recycled to the acidogenesis stage.Type: GrantFiled: March 18, 1996Date of Patent: January 7, 1997Assignee: DegremontInventors: Claude Delporte, Jean-Claude Jacquart
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Patent number: 5531898Abstract: Methods for the biological treatment of sewage in a sewage treatment plant, of wastestreams and of ponds are disclosed. The methods employ a composition comprising active amounts of an enzyme mixture, B. subtilis and P. fluorescens, and a nutrient source having a COD of 10,000 mg/kg or less, of which one source is used mushroom compost. The composition is first activated in fresh water, is then acclimated in a waste moiety, and the acclimated mixture is then used to treat the main body of the waste, such as sewage sludge, a wastestream or a pond.Type: GrantFiled: April 6, 1995Date of Patent: July 2, 1996Assignee: International Organic Solutions Corp.Inventor: Daniel E. Wickham
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Patent number: 5527464Abstract: A method of handling the waste from a community begins with the collection of raw sewage and the separate collection of other bio-degradable solids. The raw sewage is separated into a liquid component and a sludge component. The sludge component of the sewage is combined with the bio-degradable solids in a single bio-mass and adjusted to a relatively dry bio-mass of at least 22-33 percent solids. Fermentated aerobically until a temperature of 60.degree.-65.degree. C. is reached, the ferment is then anaerobically fermentated to produce a high grade manure.Type: GrantFiled: December 6, 1994Date of Patent: June 18, 1996Inventors: Istvan Bartha, Sandor Heredy
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Patent number: 5525229Abstract: A process for the anaerobic digestion of organic carbonaceous material is disclosed. The process includes the steps of (a) hydrolyzing organic carbonaceous material to produce a digester stream including hydrolysis products; (b) subjecting the digester stream to a first methanation phase operating at thermophilic conditions to produce a gaseous product including methane; and (c) subjecting the digester stream to a second methanation phase operating at mesophilic conditions to produce further gaseous product including methane, and to recover heat. An apparatus for the anaerobic digestion of organic carbonaceous material is also disclosed.Type: GrantFiled: September 14, 1994Date of Patent: June 11, 1996Assignee: North Carolina State UniversityInventor: Jason C. H. Shih
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Patent number: 5500123Abstract: A process for improved methane production by two-phase anaerobic digestion of organic carbonaceous material in which organic carbonaceous material is fermented under anaerobic conditions in an acid phase digester, forming a liquid/solids effluent, the liquid/solids effluent is fermented under anaerobic conditions in a methane phase digester, product gas comprising methane is withdrawn from the methane phase digester, and oxygen is introduced into the methane phase digester. In a preferred embodiment, the methane phase liquid effluent is passed through a CO.sub.2 stripper resulting in stripping of CO.sub.2 and H.sub.2 S from the methane phase liquid effluent. The resulting stripper liquid effluent comprising dissolved oxygen is then recycled back to the methane phase digester.Type: GrantFiled: November 8, 1994Date of Patent: March 19, 1996Assignee: Institute of Gas TechnologyInventor: Vipul J. Srivastava
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Patent number: 5492624Abstract: Processes for the treatment of organic waste are disclosed, including feeding the organic waste to an ATAD reactor and subjecting the organic waste to biological digestion in the ATAD reactor in order to produce a biomass and clear decant therein, oxidizing at least a portion of the biomass so as to produce an oxidized effluent therein, and returning the oxidized effluent to the ATAD reactor. Variations on these processes which are disclosed include the removal of nutrients from the clear decant, treating of the organic waste with a mixer prior to feeding it to the ATAD reactor, feeding the waste by a grinder upstream of the mixer, feeding the mixed material initially to an AAD vessel from which methane gas is removed, and then to the ATAD reactor, with or without nutrient removal, the use of solid separation for the effluent from the ATAD reactor, and other such variants.Type: GrantFiled: September 20, 1994Date of Patent: February 20, 1996Assignee: Environmental Resources Management, Inc.Inventor: Alan F. Rozich
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Patent number: 5451319Abstract: An anaerobic digestion process for sewage sludge comprises the steps of dewatering raw sewage sludge to provide a solids content therein in the range of 10 to 25 weight %, recirculating a portion of digested sludge resulting from methane fermentation and having a dry solids content lower than that of said dewatered raw sewage sludge, adding one part by weight of the dewatered raw sewage sludge to at least one part by weight of the recirculated digested sludge, homogeneously kneading the resulting mixture for inoculation, and causing methane fermentation of the inoculated sludge mixture in a tube-shaped digestor. The inoculated sludge is moved in the longitudinal direction of the tube in the digestor during methane fermentation, and a portion of the sludge discharged from the digestor is recirculated.Type: GrantFiled: February 28, 1994Date of Patent: September 19, 1995Inventor: Yoshio Kobayashi
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Patent number: 5417861Abstract: A method for treating bioorganic or raw or treated wastewater sludge so that a stability based upon achieving a significant microbial population, conductivity level and percent solids, is developed rapidly, is provided for indefinitely and is independent of climatic conditions. A dewatered sludge that has not been treated (i.e., raw) or a sludge that has been treated to a PSRP level or a sludge that has been treated to a PFRP level, i.e., pasteurized or sterilized sludge when still in a wet condition, i.e., between 12%-30% solids, or when in a dry condition, i.e., between 30-60% solids, is mixed with alkaline adsorptive materials to reduce odor, to increase the percent solids and to facilitate granulation, is adjusted to a mildly alkaline pH, and is adjusted to an ionic conductivity which will allow the sludge to mature rapidly when seeded with a beneficiating microbial flora. This process will reduce the pH or a high alkaline treated sludge, e.g., often above pH 12, to a physiological pH of between 7 and 9.Type: GrantFiled: December 21, 1993Date of Patent: May 23, 1995Assignee: N-Viro International CorporationInventor: Jeffrey C. Burnham
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Patent number: 5409610Abstract: Method and apparatus for anaerobically digesting sludge by filling an anaerobic sludge digestion vessel having a top and bottom and a substantially vertical draft tube with an upper end spaced downward of the vessel top and a lower end spaced upward of the vessel bottom, with liquid sludge to a level substantially above the draft tube upper end; feeding a pressurized stream of liquid sludge to the inlet side of an upwardly directed jet nozzle operatively positioned and in communication with a substantially vertical venturi tube having a lower inlet and forming part of the draft tube lower end to a lower pressure thereby creating suction at the venturi tube inlet and producing a pumping action which causes a stream of liquid sludge in the vessel bottom space to flow into and upwardly in and out of the draft tube upper end and to thoroughly admix and disperse with the pressurized sludge stream supplied to the jet nozzle and also causing downward circulating flow of liquid sludge in the vessel.Type: GrantFiled: November 2, 1992Date of Patent: April 25, 1995Inventor: Sidney E. Clark
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Patent number: 5360546Abstract: A method for treating an organic sludge is provided which can sufficiently and efficiently solubilize an organic sludge to afford a high load of anaerobic digestion treatment with an improved digestion ratio and methane gas recovery amount thereby to widely decrease the amount of the organic sludge discharged from the method. The method includes a hot alkaline treatment for causing the organic sludge to become alkaline while maintaining the temperature of the sludge to ambient -100.degree. C. to solubilize organic matters in the sludge, and an anaerobic digestion treatment of anaerobically digesting the organic sludge after the hot alkaline treatment at a temperature of 20.degree.-60.degree. C. at a pH of 7.3-9.2.Type: GrantFiled: March 31, 1993Date of Patent: November 1, 1994Assignee: NGK Insulators, Ltd.Inventors: Yoshiho Tomita, Noriaki Inagaki, Atsushi Miyata, Shigehiro Suzuki
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Patent number: 5290450Abstract: An anaerobic digestion process for sewage sludge comprises a first step of dewatering the raw sewage sludge to provide a solids content therein of at least 10 weight %. A portion of digested sludge resulting from methane fermentation is recirculated and added to the dewatered raw sludge, the weight ratio of digested sludge to dewatered raw sludge being at least 1:1. The resulting mixture is homogeneously kneaded and then subjected to methane fermentation. At least one of the dewatered raw sludge prior to the recirculating step and the kneaded sludge mixture during methane fermentation is subjected to thermal treatment at a temperature not less than 50.degree. C.Type: GrantFiled: October 15, 1990Date of Patent: March 1, 1994Inventor: Yoshio Kobayashi
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Patent number: 5275733Abstract: A method for treating wastewater sludge so that a stability based upon achieving a significant microbial population, conductivity level and percent solids, is developed rapidly, is provided for indefinitely and is independent of climatic conditions. A dewatered sludge that has not been treated (i.e., raw) or a sludge that has been treated to a PSRP level or a sludge that has been treated to a PFRP level, i.e., pasteurized or sterilized sludge when still in a wet condition, i.e., between 12%-30% solids, or when in a dry condition, i.e., between 30%-60% solids, is mixed with alkaline adsorptive materials to reduce odor, to increase the percent solids and to facilitate granulation, is adjusted to a mildly alkaline pH, and is adjusted to an ionic conductivity which will allow the sludge to mature rapidly when seeded with a beneficiating microbial flora. This process will reduce the pH of a high alkaline treated sludge, e.g., often above pH 12, to a physiological pH of between 7 and 9.Type: GrantFiled: February 20, 1992Date of Patent: January 4, 1994Assignee: N-Viro Energy Systems Ltd.Inventor: Jeffrey C. Burnham
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Patent number: 5271845Abstract: Waste sludges containing up to 35% weight percent hydrocarbon contaminants and up to 50% weight percent inorganic materials are treated to induce acclimation of indigenous microbes present therein, the acclimated indigenous microbes thereby releasing extra-cellular enzymes capable of catalyzing hydrolysis of at least the hydrocarbon contaminants in the waste sludges. This step is pursued until a substantial increase of biological activity takes place in the waste sludges. Biological activity is allowed to continue at an increased rate until the hydrocarbon contaminants are substantially biodegraded.Type: GrantFiled: March 30, 1992Date of Patent: December 21, 1993Assignee: Sanexen Services Environmentaux Inc.Inventor: Jean Paquin
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Patent number: 5264349Abstract: Method for determining in an accelerated manner the biodegradability of at least one product under anaerobic conditions which are similar to those in a dump, characterized in that a mixture with a dry substance content of between 25 and 50% is prepared with more than 80 weight-% of an active anaerobic inoculum and less than 20 weight-% of the product, on the one hand, at least one quantity of this mixture and, on the other hand, at least one quantity of the inoculum is subjected in the same manner to a fermentation at a temperature of between 30 and 60 degrees Centigrade in anaerobic conditions, the amount of biogas that is released with both these fermentations is separately measured or calculated, starting with these amounts the amount of biogas produced by the product alone is deduced and starting with the latter amount the degradability of the product itself is determined, this is the amount of carbon which was degraded from the product and converted into CO.sub.2 and CH.sub.4.Type: GrantFiled: April 19, 1991Date of Patent: November 23, 1993Assignee: Organic Waste Systems, naamloze vennootschapInventor: Luc A. De Baere
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Patent number: 5248602Abstract: A process and an installation for utilizing organic substances are proposed, in which the substances are correspondingly comminuted and processed by mixing and reaction stages to utilizable compost.The installation essentially comprises a heatable fermenter with a stirrer located therein. In order to obtain an approximately closed process circuit the comminuted substances are supplied as so-called fresh material by a supply shaft to a conveying shaft constructed as a heat exchanger and undergo corresponding heating therein. Through further supply of fresh material the already heated fresh material is supplied to the fermenter and mixed therein by the stirrer accompanied by further heating.The fermented matter formed in the fermenter, on supplying further fresh material, can be admixed in a specific ratio as so-called bacterial inoculum with the fresh material throughout the process circuit.Type: GrantFiled: April 9, 1991Date of Patent: September 28, 1993Assignee: Walter SchmidInventors: Walter Schmid, Christian Widmer, Arthur Wellinger
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Patent number: 5207911Abstract: The urban waste is crushed (2) to dimensions no greater than 5 cm and intimately mixed (5) with a aqueous suspension of biological sludge preconditioned at a temperature of from 40 to 100.degree. C. (6) and having a dry content of from 3 to 30% by weight, the suspension thus obtained, inoculated with bacterial strains (7) which can effect anaerobic break-down, being supplied to a closed fermentation cell (11, 12, 13) operated as a fluidised bed and being kept under anaerobic fermentation conditions in the cell until the emission of biogas has effectively ceased. In the fermentation cell the suspension percolates through filtration means constituted by a non-woven textile covering the walls and the base of the cell and the flow of percolated suspension is recycled to the cell. The filtration means also facilitate the separation of the biogas evolved.Type: GrantFiled: September 7, 1990Date of Patent: May 4, 1993Assignee: Rosewell LimitedInventors: Roberto Pellegrin, Silvio Tasca, Franco Tasca
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Patent number: 5185079Abstract: An anaerobic sequence batch process carried out in a single vessel. The biological reactions occur under anaerobic conditions and the vessel is operated on a fill-and-draw basis in a sequential manner. When waste is entering the reactor, the vessel is mixed by biogas or liquid recirculation. Waste feeding continues until the reactor is filled to its predetermined full liquid level. The anaerobic reaction proceeds with intermittent or continuous mixing. Mixing is then discontinued, allowing the biomass to settle under quiescent conditions resulting in the formation of a low suspended solids supernatant. After sufficient time in the settling cycle, supernatant is withdrawn from the reactor lowering the reactor contents to the predetermined lower liquid level. Gas or liquid recirculation mixing is then begun again along with waste feeding. Excess biomass is wasted from the reactor on a periodic basis.Type: GrantFiled: May 16, 1991Date of Patent: February 9, 1993Assignee: Iowa State University Research Foundation, Inc.Inventor: Richard R. Dague
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Patent number: 5141646Abstract: A process for the treatment of organic waste is described which comprises the steps of:a) feeding input waste in an input line to an ATAD reactor where the waste is subjected to biological digestion;b) settling out a portion of a biomass formed in the digestion unit;c) hydrolyzing the separated portion in a hydrolysis vessel;d) returning hydrolyzed effluent to the input line upstream of the ATAD reactor; ande) periodically removing clear decant from the reactor. Variations of this process include removal of nutrients from the clear decant; feeding solid organic waste by a grinder upstream of the mixer; feeding the mixed material initially to an AAD vessel from which methane gas is removed, and then to the ATAD reactor, with or without nutrient removal.Type: GrantFiled: March 12, 1991Date of Patent: August 25, 1992Assignee: Environmental Resources Management, Inc.Inventor: Alan F. Rozich