Abstract: A plant for generating biogas from organic biodegradable material containing liquid and solid components, such as waste products, in particular liquid manure from agricultural enterprises, comprises a biogas generation container (9) having a feed for the degradable material and a biogas collection zone (6) having a biogas outlet, and a flotation separation unit having a microbubble generation unit (15) for separating off the solid components from the liquid components of the degradable material. The flotation separation unit comprises a chamber region (14) which is delimited in the interior of the biogas generation container and essentially active in the direction of gravity and having a closed bottom and an open upper end arranged below the liquid level of the biogas generation container. Clarified liquid form the chamber region and a gas, in particular the biogas from the biogas collection region, can be fed to the microbubble generation unit for charging the liquid with gas.

Abstract: A method and an apparatus for processing organic material, the method employing at least two reactors and including the steps of combining carbon dioxide or carbon-dioxide containing gas and ammonia or ammonia-containing material in a first reactor to form a buffer compound/buffer compounds, then feeding the buffer compound or buffer compounds formed in the first reactor into a second reactor, and performing bioconversion on organic material in the second reactor. In that case, the carbon dioxide of the mixed carbon dioxide gas reacts with the ammonia, forming a buffer compound, such as ammonium bicarbonate and/or ammonium carbonate.

Abstract: An economical, integrated system works in series with anaerobic digestion of animal waste to recover nitrogen and phosphorous, while also scrubbing the produced biogas.

Abstract: A method of treating a mixture of microorganisms containing phosphorus and magnesium, by first inducing the mixture microorganisms to release phosphorus and magnesium which is then tapped off as the mixture is thickened, to produce phosphorus and magnesium-rich liquid and phosphorus and magnesium-reduced treated mixture. This treated mixture is placed in an anaerobic digester where ammonia is formed but combines very little with phosphorus or magnesium as these elements have been greatly reduced in concentration. Next the high-ammonia mixture is dewatered, to produce an ammonia-rich liquid, which is combined with the phosphorus and magnesium-rich liquid. In one preferred embodiment a useable struvite product is harvested from this combination. Additionally, the production of nuisance struvite in the anaerobic digester is greatly reduced, in comparison with prior art waste treatment methods.

Abstract: The disclosed invention is an improved method for treating ethanol distillation still bottoms by recovering, through solids separation and pressurized membrane filtration, potable water from still bottoms for human consumption by bottling or for reuse, and concentrating the solids with beneficial properties recovered such as chemicals, nutrients and medicinals before anaerobic digestion. The invention is an improved process because it can reduce the volume of solids to manage, recovers the water from the fermentation still bottoms while pasteurized, maintains the chemical arid physical properties of solids for beneficial property recovery, improves ethanol and energy efficiency, and results in clean discharge to the environment including carbon dioxide recovery. A bioreactor produces a gas rich in methane fuel from the concentrate to power the pressurized tiltration process and an aqueous ammonia solution to recover or recycle.

Abstract: A tubular plug flow digester system assembled from manufactured components, including a holding/heating tank (15) connected to a manifold (14) that feeds a single or multiple parallel injection pumps (12). These pumps force feedstock though check valves (13) and into single or parallel digester hulls. This hulls are composed of manufactured parts including tapered end sections (11) and hull sections (10) that can be assembled onsite to a configuration that accommodates operational needs. Biogas produced by this digester is pressurized due to a liquid column created by an elevated effluent outlet (25). Feedstock is inoculated with relevant microorganisms that promote the generation of methane-rich biogas. Inoculation members (26) positioned within the hulls shelter biofilms containing these microbes while allowing regions of the biofilm to slough or naturally release microbes into the flowing feedstock stream. Biogas is collected through a manifold (22) and its release is controlled by a regulator or a valve.

Abstract: A digester processes animal waste and other organic matter by accelerating the natural bacterial process of digestion. This is achieved by constructing a system that mimics the natural physical dimensions and properties of a mammal's digestive tract and then accelerates the process through the selective breeding of aggressive bacteria to promote the digestion. Examples of suitable waste include but are by no means limited to animal waste, industrial waste, spent barley, kitchen waste and the like.

Abstract: The present invention provides methods for the generation of methane by a two phase anaerobic phase system (APS) digestion of organic substrates. Also provided is a device for practicing the methods of the invention. The APS-digester system is a space-efficient, high-rate solids digestion system. The APS-digester system consists of one or more hydrolysis reactors, a buffer tank and one biogasification reactor.

Abstract: The process and system of the invention converts biomass materials into energy to power a large marine vessel without the problematic environmental releases of either liquids to the sea or greenhouse gases to the atmosphere. The biomass is conveyed to an on-board biomass storage facility and converted to synthesis gas in an on-board gasification unit to synthesis gas that is used as fuel for fuel cells to power the marine vessel. A portion of the biomass is sea biomass harvested from the sea and removed from the sea by on-board biomass removal means that strains the biomass from the sea water and flips the biomass into a holding bin before being conveyed to the biomass storage facility. A portion of the synthesis gas is converted to useful products. These products are partially used as fuel for the fuel cells. The remaining products are off-loaded at port facilities where biomass waste materials are loaded on-board and conveyed to the biomass storage to serve as the remaining portion of biomass.

Abstract: Bioventing methods create a bacterial treatment zone at a contaminated site by supplying a hydrocarbon food source to the treatment zone, and recirculating the hydrocarbon to the treatment zone. The inventing methods may inject, circulate, extract and reinject hydrocarbons such as butane or other alkanes to the subsurface at a contaminated site to create a bacterial treatment zone. Contaminated vapors extracted from the soil and/or groundwater may be reintroduced into the site. Hydrocarbons that are not consumed by the bacteria in the treatment zone may be extracted and recovered for recirculation into the treatment zone.

Abstract: Carbon dioxide from a process which oxidizes a carbon containing feed is separated and reduced to carbon monoxide using a carbon dioxide reduction reactor [22, 26] coupled to a water gas shift reactor [14], to simultaneously reduce carbon dioxide emissions and increase the product yield of clean fuels. In the preferred underground carbon gasification application, these reduction and shift reactions are substantially promoted by utilizing temporary [24] and permanent storage [28] of the carbon dioxide and carbon monoxide coupled with cyclic operational procedures. Additional advantages include carbon dioxide sequestration, removal of contaminants from the groundwater affected by the process and the ability to influence groundwater flow patterns to improve gasification efficiency and reduce potential environmental effects.

Abstract: A method for manufacturing a biomass enriched with hydrogen-producing bacteria or spores includes providing a biomass comprising a hydrogen-producing bacteria and a competing bacteria and treating the biomass with a sufficient amount of a chemical agent for a period of time such that the treatment (i) kills, inhibits or injures substantially all of the competing bacteria and (ii) does not kill or inhibit the hydrogen-producing bacteria or causes the hydrogen-producing bacteria to form spores that are not destroyed during the chemical treatment. The method also includes digesting an enriched biomass with a non-sterile organic substrate. The enriched biomass includes hydrogen-producing bacteria or spores that are mixed in sufficient quantities with the organic substrate such that the hydrogen-producing bacteria can overcome the competing bacteria to consume the organic substrate and produce hydrogen.

Abstract: The process for treating an ammonium containing liquid by denitrification treatment of an ammonium containing liquid containing at least ammonium comprises carrying out nitrate reduction treatment of reducing nitrate contained in or added to the ammonium containing liquid to nitrite, and carrying out anaerobic ammonium oxidation treatment of simultaneously anaerobically denitrifying nitrite produced in the nitrate reduction treatment and ammonium contained in the ammonium containing liquid by anaerobic ammonium oxidizing bacteria.

Abstract: A process for treating a microorganism-containing stream includes the steps of passing the stream through a chamber, pressurizing the stream in the chamber to a pressure greater than 14.7 p.s.i.g., introducing a feed gas into the pressurized stream such that the feed gas is soluable within the microorganisms, and depressurizing the stream so as to cause the soluablized feed gas to expand within the microorganisms so as to rupture the cell walls of the microorganisms. The feed gas can be carbon dioxide, air, nitrogen, methane, or mixtures thereof.

Abstract: Provided herein are methods and system for the production of biogas, U.S. Environmental Protection Agency classified Class A Biosolids, and pathogen reduced organic liquid fertilizer. Through the digestion of waste materials using sequential phases in an efficient digestion process, enhanced biomass conversion efficiency and improved output of products (in quantity and/or quality) are obtained with a significant reduction in dwell time in each phase.

Abstract: The present invention is directed to a process for the production of ethanol and energy. The process includes the steps of fermenting a corn mash in an aqueous medium to produce a beer. Next, the beer is distilled to produce ethanol and a whole stillage. The whole stillage is anaerobically digested to produce a biogas and a residue. The biogas is combusted to produce electricity and steam. The electricity and steam are used during the fermentation and distillation process. The residue may further be separated into a liquid fertilizer and top soil residue.

Abstract: An anaerobic wastewater treatment system includes a recycle tank, a bioreactor tank and a bioselector for recapturing anaerobic microbial consortia particles escaping from the bioreactor tank and returning them to the bioreactor tank. The bioreactor tank receives recycled wastewater feed from a recycle tank and discharges via an overflow outlet treated wastewater and microbial consortia particles to a bioselector. The bioselector is adapted to separate entrained microbial consortia particles and return a feed to the bioreactor tank which including some of the treated wastewater received from the bioreactor tank and the microbial consortia particles received from the bioreactor tank. The bioselector provides a recycle feed to the recycle tank. Overflow from the bioselector provides an effluent of treated wastewater leaving the system.

Abstract: Systems and methods are provided for converting organic waste materials from a municipal waste stream to useful products, such as fuels. Through the use of a biomixer and a hydropulper, as well as through sorting and screening, the organic waste materials are progressively reduced in size and cleaned of contamination. The resulting uniform biomass is suitable for anaerobic digestion to produce biogas and a residual solid that is suitable for producing a high quality compost. A quantity of liquid organic waste material can be added to the biomixer, to the hydropulper and/or to the anaerobic digester. The quantity of liquid organic waste material can be obtained by separating the liquids from any containers and can be stored in a holding tank prior to being added to the biomixer, the hydropulper and/or the anaerobic digester.

Abstract: A method and system for ballast water treatment are provided. A vacuum is applied directly to an existing vent of a vessel's ballast water tank during the vessel's voyage. The applied vacuum is in a range of approximately ?2 to ?4 pounds per square inch. To further assure success, living organisms can be added into the ballast water tank to consume (i) oxygen dissolved in the ballast water, and (ii) food sources for selected organisms contained in the ballast water. No modifications to the vessel's ballast water tank are required as all system components are coupled to the existing vent.

Abstract: A method of converting biological material into energy resources includes transmitting biological material to a pulsed electric field (PEF) station, and applying a PEF to the biological material within a treatment zone in the PEF station to generate treated biological material. The method also includes transmitting the treated biological material to a biogenerator, and processing the treated biological material in the biogenerator to produce an energy resource. A converter may carry out this process, and may include the PEF station and the biogenerator.

Abstract: The invention relates to using alcalophilic sulphate-reducing bacteria selected from at least one species of a Desulfohalobiaceae or Desulfonatronum species family or from species whose gene encoding for ribosomal PARN 16S has a homology equal to or greater than 97% with a corresponding gene of any species of the Desulfohalobiaceae or Desulfonatronum species family for producing a hydrogen sulphide substantially soluble in an aqueous medium.

Abstract: A method and related apparatus for oxidation and reduction of a reduced aqueous nitrogen contaminant.

Abstract: The present invention relates to a method and a facility for conversion of organic waste into biogas, i.e. a methane containing gas, with an improved efficiency and economy. The method comprises three consecutive steps of: i) digestion of the organic waste in a first reactor; ii) hydrolysis of the digested organic waste in an anaerobic hydrolysis tank; and iii) digestion of the hydrolyzed organic waste in a second reactor; wherein evolved gases are removed from the anaerobic hydrolysis tank.

Abstract: The present invention provides a closed sulfur circulation wastewater treatment system, which combines autotrophic and heterotrophic denitrification to recycle sulfates. Particularly, the present invention provides a process and a system for wastewater treatment which effectively process wastewater having both high nitrates and low organic carbonaceous sources, and effectively reduce sulfates by-products.

Abstract: A system and method integrating treatment of waste, polar Fats/Oils/Greases (FOG) with conventional anaerobic wastewater treatment facilities for biologically fueling digestion of solids in, and steady state production of methane from treated wastewater streams that includes a slipstream loop circulating warmed, actively digesting sludge from the base to the head of the anaerobic wastewater treatment facility, a conditioning tank with input screened by a rock trap, actively digesting sludge pumped from the slipstream loop into the tank via the rock trap, before and after FOG wastes are pumped from a hauler tank via a hose connecting to the rock trap into the conditioning tank and mixed with actively digesting sludge in the tank to produce a feedstock slurry rich in volatile fatty acids for injection at a metered rate back into the actively digesting sludge slipstream loop for introduction at the head of the anaerobic wastewater treatment facility.

Abstract: A reactor (10) for anaerobic waste water treatment is designed as a loop-type column reactor comprising a central flow channel (20). In the annular space (40) between the central flow channel (20) and the reactor wall, there are positioned carrier elements (50) for immobilizing microorganisms, with flow passages being provided between adjacent carrier elements (50). The lower portion of the reactor (30), below the carrier elements, is designed as a space intended to receive waste water having microorganisms floating therein during operation of the reactor (10). During operation, there are provided both floating microorganisms and microorganisms that are immobilized on the carrier elements. The waste water to be treated flows centrally downward and up again along the carrier elements (40), with the flow being generated in part by the gas development of the microorganisms.

Abstract: In wastewater treatment equipment, a surfactant is added to a micronanobubble reaction vessel 3 by using a surfactant pump 8 and a surfactant tank 9 which constitute a surfactant adding section. Thereby, a micronanobubble generator 4 stably and efficiently produces micronanobubbles in the treatment water as raw water containing the surfactant in the micronanobubble reaction vessel 3. Thus, the micronanobubbles make it possible to efficiently pretreat the wastewater introduced into the micronanobubble reaction vessel. Consequently, it becomes possible not only to enhance efficiency of wastewater treatment but also to reduce a treatment load on wastewater treatment equipment 14 in a step subsequent to the pretreatment. Thereby, scale of the wastewater treatment equipment 14 is reduced.

Abstract: A system and method for removal of uranium and other contaminants from aqueous solution, utilizing live algae, are described. The system includes a bioreactor, in which a reaction mixture of live algae, preferably photosynthetic algae, and contaminated solution are introduced; a means for introducing carbon dioxide gas in the reaction mixture; a means for exposing the reaction mixture to light; means for mixing and impelling the reaction mixture; and means for separating out algae from remediated solution.

Abstract: An apparatus is provided that includes: a containment system 208 having at least one sidewall and bottom that are substantially impermeable to a passage of water; a distribution system 124 to introduce an aqueous stream comprising nitrates into the containment system; a de-nitrification system 128 comprising a de-nitrification media, the media being contained within the containment system; a pump to pressurize the stream and cause the stream to pass through the de-nitrification media, thereby converting at least most of the nitrates into nitrogen gas and forming a treated stream; and a collection system 132 to remove the treated stream from the containment system.

Abstract: The invention relates to a method for decomposing biogenic material, wherein a percolator is charged with biogenic material, a percolation liquid is separated by sieving and re-sprayed again onto the biogenic material, excess percolation liquid is pumped into a buffer from where it is transported into a biogas reactor and fermented to form biogas. The method is characterized in that the purified percolation liquid is transferred as waste water to a storage buffer container from where it can be retransferred to the percolator.

Abstract: A new process for the production of methane gas from flush dairy operations utilizing heated baffles in a lagoon is disclosed. The baffles are aligned in rows with the rows oriented perpendicular to the flow of nutrient-rich liquid through the lagoon. The baffles are indirectly heated by either hot water or steam and are suspended sheets of porous material upon which methane-producing bacteria are resident. The methane is contained beneath and removed from an enclosing cover over the lagoon.

Abstract: A method and a facility for the treatment of waste from concentrated animal feed operations are disclosed. The method includes receiving manure at a central location, digesting the manure and producing therefrom combustible gases, solid matter and water containing dissolved organic pollutants. The combustible gases are used to provide energy and the water is separated from the solid matter. The solid matter is dried to produce a useful bedding material and the water is treated using an activated sludge aeration system to reduce the dissolved organic pollutants to carbon dioxide, bacteria and water. The facility includes various means for executing the method and includes an ultrasonic treatment station for disrupting bacteria cell walls to improve digestion efficiency.

Abstract: A method for the removal and sequestration of ammonia nitrogen from anaerobic fermentation effluent while producing a higher BTU biogas. The method includes the steps of removing the slurry from the digester, stripping the ammonia from the slurry or portion thereof with a high BTU biogas, blending the stripped ammonia with the digesters biogas to remove the carbon dioxide and precipitate ammonium bicarbonate/carbonate as a solid while producing a high Btu biogas, a portion of which is used to strip the ammonia and CO2 from the slurry. The process removes ammonia nitrogen from the digester effluent while producing a high Btu biogas and a solid ammonium bicarbonate/carbonate product. Ammonia stripping is accomplished with a recycled stripping gas deficient in CO2 and ammonia that is capable of removing the CO2 and ammonia from solution by virtue of the lower partial pressures of CO2 and ammonia in the stripping unit.

Abstract: A method for reducing the odors of an anaerobically digested dewatered biosolids or other biosolids or sludge may include separating first anaerobically digested dewatered biosolids into first and second portions, storing second anaerobically digested dewatered biosolids, removing a portion of the second biosolids, and mixing the removed second biosolids portion with the first portion of the first biosolids. The method may be implemented in a system including a separation device, first, second and third transporters, a storage area, and a mixer. The separation device may separate the first biosolids into first and second portions. The first transporter may transport the first portion to the mixer. The second transporter may transport the second portion to the storage area. The storage area may store the second portion for a select time period. The third transporter may transport a portion of the stored first biosolids to the mixer for blending.

Abstract: A chemical/biological wastewater treatment plant method and apparatus employing rapid sludge chemical dewatering technology in conjunction with an environmental biological system for treating the separated treated wastewater by land applying it for plant consumption, and/or passing it through aqueous plant or microbial reduction of the dissolved solids and ammonia for BOD compliance to produce water of sufficient quality to meet open stream and ocean effluent discharge requirements; and disposing of the high BTU low moisture solids.

Abstract: Compositions, methods and apparatus for the production of methane gas from poultry litter are provided. Particular features are selection of methanogens, well stirring of the digester, and control of critical parameters of digester temperature, pH, and solids content resulting in enhanced methane production and reduced nitrogen compositions. A benefit of the invention is the capability to maintain a closed system without waste by-products.

Abstract: A method of treating sewage sludge comprises a pathogen reduction stage in which raw sludge is incubated for a predetermined incubation period at a temperature in the mesophilic temperature range. The sludge is incubated in a plurality of sequential vessels (1a,1b,1c) comprising an upstream vessel (1a) which receives the raw sludge to be incubated and a downstream vessel (1c) which discharges the incubated sludge. The sludge is fed from the upstream vessel (1a) to the downstream vessel (1c), via any intermediate vessels (1b), and subsequently discharged after spending a predetermined residence time in each vessel, the total residence time being said predetermined incubation period.

Abstract: An induced sludge bed anaerobic reactor includes a vessel in which a septum or other partition is positioned to maintain solids in wastewater being treated toward a lower zone in the reactor. A gas trap, which may also comprise an overpressure protection device, may be arranged at an outlet of the vessel. A distribution plate may be located at an inlet. A central aperture is formed in the septum into which a plug control mechanism, such as an auger, may be positioned to force solids to the lower zone of the reactor or, alternatively, pull solids up above the septum so that they can be removed from the vessel, if desired. A mixer may be utilized in connection with the bioreactor to mix the contents and prevent a crust from forming at the top of the bioreactor. Still further, a wall may be positioned to extend above the septum around its perimeter to assist in separating solids from the wastewater.

Abstract: A method and apparatus for an anaerobic digestion of biomasses with generation of biogas and sludge, wherein a hydrolyzation phase and a following fermentation of the biomass are included, wherein a hydrolyzation phase (5) and at least two following fermentation phases (7,8,9) are included and wherein the hydrolyzation (5) as well as the following fermentations (7,8,9) are performed in separate containers with specific measurement and control of the temperature, of the mixing degree, of the pH value and of the pressure.

Abstract: A method and apparatus for the anaerobic digestion of high-solids waste material. The apparatus includes a closed container having a relatively circular outer wall. The closed container has a first passage having an inlet in which the waste material flows in a first direction, a second passage in which the waste material flows in a second direction, and a divider having an end. The divider separates the first passage from the second passage, such that the waste material flows around the end of the divider when flowing from the first passage to the second passage. An access port is provided in a roof of the closed container with a sleeve extending into the waste material within the container. A conduit is advanced through the sleeve into the closed container for suctioning debris out of the closed container.

Abstract: The present invention relates to a method for producing hydrogen by batch process capable of replacing the existing complex continuous organic waste treatment system by using pretreated organic waste not only as a substrate but also an inoculum. According to the present invention, the existing complex continuous process can be changed into a simple batch process, thereby reducing the installment costs and operational costs. It is possible to obtain economic operation because a long initial start-up period is not required.

Abstract: The present invention discloses an Up-flow Multi-stage Anaerobic Reactor (UMAR) used for treatment of medium/high concentration organic wastewater. The stated UMAR with forced internal circulation, improved phase separator and added sludge inlet overcomes the disadvantages of a lower load, a longer hydraulic retention time and a larger dimension in traditional anaerobic reactors. The forced internal circulation increases capacity and cycles of internal circulation thus increased efficiency of contaminant removal. The fast jetting is avoided and efficiency of gas/liquid separation is increased by an improved bending outlet of up flow pipe. The simplified sludge addition and usage are obtained by a sludge inlet. The load of UMAR in this invention can reach about 30 kgCOD/(m3d) for treatment of medium/high concentration of organic wastewater from pulp and paper process and similar wastewater, being about four times of load and capacity of traditional Up-flow Anaerobic Sludge Bed (UASB) reactors.

Abstract: Methods and apparatus for continuing, automated control of wastewater treatment processes. In certain preferred embodiments, method and apparatus for control of aeration in suspended growth biological treatment processes, especially in activated sludge processes.

Abstract: A method and apparatus for anaerobic treatment of wastewater and sludge in a digestive reactor in which the length of stay of hydraulic components is decoupled from that of particulate components by discontinuous removal of a portion of the digesting sludge from the digestive reactor, enrichment of the extracted portion of the digesting sludge in a sapropel reactor, and feedback of the enriched digesting sludge into the digestive reactor.

Abstract: A method and system for ballast water treatment are provided. Living organisms are added into a vessel's ballast water tank (e.g., via an existing vent) to consume (i) oxygen dissolved in ballast water contained in the ballast water tank, and (ii) food sources for selected organisms contained in the ballast water.

Abstract: In a biological wastewater treatment system, the addition of an intermittently aerated second bioreactor to accomplish ammonium oxidation to predominately nitrite and then to achieve denitrification by introducing the effluent, containing nitrite, from the second bioreactor into the influent collection system or the head works of a wastewater treatment plant. Denitrification from nitrite occurs in the collection pipe using the influent organics as a carbon source.

Abstract: A system for recycling drilling sludge is disclosed. The system has a treatment area and a salt-tolerant bio-reactor coupled to the treatment area. The bio-reactor has i) at least one bio-suspension element for supporting the growth of at least one type of biological microorganism within an enclosed flow zone; ii) an agitator for creating a flow of the drilling sludge through the enclosed flow zone at a flow rate; and iii) an aerator for providing a gas to the enclosed flow zone. The system also has a processor coupled to the agitator and configured to create at least a minimum self-cleaning drag force between drilling sludge passing through the enclosed flow zone and the combined at least one type of biological microorganism and the at least one bio-suspension element. A related method and bio-reactor are also disclosed.

Abstract: A process for the stabilization and disinfection of sludge wherein a) raw sludge having a dry matter content of from 3 to 7% by weight is fed continuously or quasi-continuously into a first stage, where it remains for an average retention time of three to ten days under aerobic-thermophilic conditions to obtain a partially stabilized sludge; and b) the partially stabilized sludge is fed into a second stage in which disinfection of the partially stabilized sludge is effected at temperatures of at least 50° C., wherein prior to discharging, there is no charging until the partially stabilized sludge has been disinfected.

Abstract: An object of the present invention is to provide a process for a high-performance upflow anaerobic sludge treatment (methane fermentation treatment) targeting an organic wastewater containing an inorganic sulfur compound and an apparatus therefor. The invention relates to a process for methane fermentation treatment of an organic wastewater containing a sulfur compound, which includes: detecting a concentration of hydrogen sulfide in a biogas generated from a step of methane fermentation treatment; and, conducting a control of subjecting the organic wastewater to a desulfurization treatment operation in the case that the concentration of hydrogen sulfide in the biogas exceeds a predetermined value, and to an apparatus therefor.

Abstract: Disclosed is a method for the aerobic-thermophilic stabilization and decontamination of sludge, in which a) raw sludge having a dry substance concentration of 3 to 7 percent by weight is fed to a first stage and remains there for an average dwell time of four to ten days at minimum temperatures of 42° C. while an oxygen-containing gas is added so as to obtain partially stabilized sludge, b) said partially stabilized sludge is fed to a second stage in which the same is further stabilized and decontaminated for an average dwell time that amounts to 30 to 70 percent of the average dwell time of the first stage at temperatures exceeding 500° C. while adding an oxygen-containing gas.