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: 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: 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.

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: 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: The present invention provides a mixed bacterial culture, designated as the culture Atz Mix 1, which degrades atrazine at various temperatures (10° C. to 30° C.) in a wide range of atrazine concentrations (several ppb to ten thousand ppm), without formation of toxic metabolites. Atz Mix 1 is a stable mixed culture and includes catabolic genes trzN, atzB, atzC coding the enzymes for the degradation of atrazine to cyanuric acid, and the gene trzD coding the enzymes for subsequent opening of s-triazine ring. The invention further includes a microbiological method of degrading atrazine and other s-triazine compounds for remediation of atrazine-contaminated soils, even those rich in nitrogen, as well as for accelerating the process of atrazine mineralization in waste waters containing high concentrations of s-triazine compounds.

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 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: Integrated sewage or digestible wastes, and fats, oils, greases and waxes (FOG) waste treatment methods, systems and facilities include a slipstream loop incorporating circulation pumps, hot water heat exchangers and conventional anaerobic digesters for continuously circulating actively digesting sludge at a rate to preclude solid settlement accumulation as a warm flowable slurry source. The warmed actively digesting sludge is pumped from the slipstream loop through a rock trap into a delivery/input loop both for aiding transport or delivery of FOG waste to, and for partially filing a closed receiving/conditioning holding tank, where the warmed actively digesting sludge softens and liquefies the FOG wastes offloaded into the holding tank for further treatment at a desired treatment temperature range (whether psychrophilic, mesophilic, or thermophilic).

Abstract: Embodiments include a method and apparatus for recovering ammonia and nitrogen from a waste stream. Embodiments further include recovering ammonia using an ammonia recovery process and a biological nitrogen recovery process. In some embodiments, a return stream from the ammonia recovery process may be used to provide alkalinity, carbon substrate, and/or biological oxygen demand to the biological nitrogen recovery process. In some embodiments, a hydrothermal sludge process may be used to further treat the waste stream and provide additional return to the ammonia recovery system. Other embodiments include an ammonia recovery system for conducting the ammonia recovery process, a biological nitrification and/or denitrification system for conducting the biological nitrogen recovery process, and an optional hydrothermal sludge processing system.

Abstract: An ambient anaerobic digester system for anaerobic digestion of animal waste with biogas production and recovery is provided. The anaerobic digester system includes a substantially flexible bladder for anaerobically digesting the animal waste with biogas production and transmitting the biogas to at least one biogas storage container, biogas use device or a combination thereof. In a preferred form, the substantially flexible bladder has a waste inlet, a digester effluent outlet, one or more sludge access ports and a biogas outlet in a top surface thereof. The anaerobic digester system may inexpensively, simply, reliably, and effectively be used to treat animal waste without energy expenditure and little capital expense, thus minimizing pollution typically caused by animal waste.

Abstract: The invention relates to a method for treatment of predominantly urban sewage plant sludges, characterised in comprising a step for treatment of the sludges by microfungi.

Abstract: The invention provides improved methods of wastewater purification. The present invention provides a process for the energy efficient production of Class A biosolids. More particularly, sewage sludge is subjected to an anaerobic digestion process resulting in class A biosolids, whereby methane gas byproducts are utilized to meet the high energy demands associated with Class A biosolid production.

Abstract: The pH value of excess sludge taken out from a biological oxidation tank (2) is adjusted to 8 to 14, and the pH-adjusted sludge is injected into a solubilizing device (3). The sludge taken out from the solubilizing device (3) is heated to 110° C. to 350° C. at a pressure higher than saturated steam pressure to solubilize the sludge to a state readily degradable by microorganisms. The solubilized sludge is returned to a biological oxidizing tank (2), and the pH value of the sludge in the biological oxidizing tank (2) to 5 to 9. The use of the above method of treating excess sludge and an apparatus therefore enables substantially reducing the volume of excess sludge with economic advantage.

Abstract: An organic waste material treatment process comprising subjecting the organic waste material to conditions under which anaerobic digestion occurs followed by conditions under which aerobic composting occurs. Preferably, the organic waste material is pre-conditioned before anaerobic digestion by subjecting the organic waste material to aerobic composting conditions to facilitate a rise in temperature of the organic waste material. The treatment process is conducted in a single vessel, wherein air and water are evenly distributed to the contents of the vessel. A plurality of vessels may be interconnected, such that water may be extracted from one vessel, whose contents have undergone anaerobic digestion, then recirculated to an interconnected vessel to facilitate conditions for anaerobic digestion of the contents of the interconnected vessel.

Abstract: Apparatuses and methods for anaerobic digestion of high-solids waste are provided. The methods may include and the apparatuses may be used for moving the solid waste in a corkscrew-like fashion through a closed container. The method may further include moving the high-solids waste into contact with a heating device to facilitate the corkscrew-like movement. Other methods and apparatuses may use at least one of a partition and a conduit from which liquid or gas is discharged.

Abstract: A method for processing organic material, in which method bioconversion is performed on the organic material in at least one first reactor, the biogas formed in the bioconversion is treated with ammonia in at least one second reactor and buffer solution produced in the second reactor is recycled to the bioconversion in the first reactor. Thus, the carbon dioxide of the mixed methane/carbon dioxide gas reacts with the ammonia and forms a buffer compound, such as ammonium bicarbonate and/or ammonium carbonate.

Abstract: The present invention provides improved systems and processes for performing sequential batch anaerobic composting (SEBAC) on high solids content wastes. In particular, the present invention provides improved flooded SEBAC systems that function more efficiently (i.e., higher conversion kinetics) at lower temperatures than conventional SEBAC systems. Further, the improved flooded SEBAC systems and processes of the subject invention enable efficient anaerobic digestion operation at a smaller reactor volume ratio as compared to conventional SEBAC systems, without the displacement of leachate and clogging as a result of entrapped biogas or an increased pressure drop (hydraulic). Further, the improved flooded SEBAC systems of the invention overcome concerns associated with leachate displacement as well as excessive pressure drops.

Abstract: A method for reducing the production of sludge derived from the treatment of wastewater. The sludge is subjected to a mechanical action in the presence of a gas containing oxygen. The mechanical action is performed in such a way as to destroy the cell walls of between 5% and 80% of the microorganisms present in the sludge.

Abstract: A process and system for treating excess sludge produced from a biological treatment system. The process includes biologically treating water or wastewater and producing excess sludge. The excess sludge is directed to a solubilizer where the sludge is solubilized. The solubilized sludge is directed to a liquid/solid separator, which separates the solubilized sludge into a liquid fraction and a solid fraction. The process further includes at least partially digesting the liquid fraction and directing the partially digested liquid fraction to the biological treatment system where the liquid fraction is subjected to further treatment. Finally, the solid fraction is subject to further solubilization.

Abstract: A method for the treatment of sewage sludge which comprises the step of applying to the sludge a biologically effective amount of a composition which contains a lignosulfonate and sludge digesting microbes, preferably from the genus bacillus. The method may be practiced in sewage treatment plants and also may be used for treatment and odor suppression in holding tanks and the like.

Abstract: A process for the production of hydrogen from anaerobically decomposed organic materials by applying an electric potential to the anaerobically decomposed organic materials, including landfill materials and sewage, to form hydrogen, and for decreasing the time required to treat these anaerobically decomposed organic materials. The organic materials decompose to volatile acids such as acetic acid, which may be hydrolyzed by electric current to form hydrogen. The process may be continuously run in sewage digestion tanks with the continuous feed of sewage, at landfill sites, or at any site having a supply of anaerobically decomposed or decomposable organic materials.

Abstract: An apparatus and method for treating organic waste sludge such as sewage sludge is disclosed wherein the sludge is first dewatered, moved to a day hopper for storage, and then successively passed through first and second reactors. As the sludge is passed through the first reactor, in a continuous fashion, the sludge and acid are thoroughly mixed and has the pH thereof substantially lowered due to the addition of acid in the first reactor. The sludge is then moved through the second reactor where the sludge is subjected to a base material to substantially raise the pH thereof. The treated sludge is then pumped from the second reactor to a pugmill and then to a dryer which dries the material. The dried material is then suitable for use as a fertilizer.

Abstract: The invention relates to a method for the thermal hydrolysis of sludge characterized in that it is carried out in at least two reactors operating in parallel, in each of which the sludge undergoes a complete thermal hydrolysis cycle. Said cycle comprises different stages consisting in supplying the reactor with the sludge, injecting live stream in order to bring said sludge to a pressure P and a temperature T at which hydrolysis can occur, maintaining the sludge at said pressure P and said temperature T for a certain amount of time, suddenly bringing said sludge to the atmospheric pressure by releasing the flash steam and emptying said reactor of the hydrolysed sludge. Furthermore, the inventive method consists in time shifting the cycle of one reactor to the other in order to use the flash steam produced from one reactor to inject it into the other reactor.

Abstract: A method of treating sewage sludge comprises incubating raw sludge at a temperature in the mesophilic range to reduce the pathogen content of the sludge.

Abstract: An improved process of treating sludge to provide a stable product for use as a beneficial soil or fertilizer for agricultural lands which includes the steps of: (a) mixing sludge with at least one alkaline material in an amount sufficient to raise pH of the mixture to a level of at least 12 and to increase percent solids in the mixture to at least 40% by weight, and such that odorant sludge organics and inorganics are bound to adsorbent particles of the alkaline material, (b) aerating and drying the mixture by agitation and heating to stabilize the mixture and increase the percent solids to at least 50% by weight, and (c) pasteurizing the dried mixture at a temperature at or above 52.degree. C.

Abstract: A method of treating wastewater sludge includes pumping, continuously, raw sludge into a first digester and treating the raw sludge at a specific temperature of between about 51° C. to 60° C.; transferring the treated wastewater sludge to a batch tank; treating the wastewater sludge in the batch tank, anaerobically, at a thermophilic temperature which is not more than 2° C. warmer than the specific temperature in the first digester; and disposing of the treated wastewater sludge as a Class A biosolid. A wastewater sludge treatment system includes a first thermophilic digester for treating raw wastewater sludge at a specific temperature in a range of between about 51° C. to 60° C., and discharging a treated wastewater sludge; a batch tank for receiving the treated wastewater sludge discharged from the first digester and for thermophilically treating sludge at a temperature in a range of between about 51° C. to 60° C. and not more than 2° C.

Abstract: A method for treating particulate biodegradable organic waste includes sizing the waste and adding a base prior to introducing the waste to a thermal hydrolysis reactor and hydrolyzing the waste at a temperature of about 130° C. or greater and a pressure greater than the saturated water vapor pressure to produce a slurry including solubilized organic material and residual solids. The solubilized organic material is separated from the residual solids using a liquid/solid separator and the solubilized organics are subjected to anaerobic digestion to produce a methane gas. The base is preferably potassium hydroxide (KOH) at a concentration of about 1%. The method may further include preheating the particulate biodegradable organic waste with latent heat of the separated solubilized organic material prior to thermal hydrolysis.

Abstract: A sewage treatment system is disclosed in which a waste stream is separated into a primary sludge and water effluent, and the primary sludge is anaerobically digested and dewatered to produce a Class A biosolid. The water effluent is aerobically digested and separated to provide a waste activated sludge. The waste activated sludge is heated in a two-stage process with steam injection and indirect steam before it is passed to a hydrothermal process. The pH of the treated waste activated sludge is then increased, and the nitrogen is stripped and recovered as an ammonium salt. A low nitrogen stream with volatile fatty acids and soluble organics is then separated and fed to the aerobic digester. Biogas generated during anaerobic digestion provides energy for heating the waste activated sludge for the hydrothermal process, and reject heat from the hydrothermal process heats the primary sludge for thermophilic anaerobic digestion.

Abstract: A denitrification system for denitrified wastewater or nitrified water treatment using a detergent or detergent-like compound comprising available carbon. The system comprises a plurality of interconnected tanks including a mixing tank which feeds detention tanks which in combination provide a detention time period for the effluent. A controller determines the amount of detergent dispensed into the mixing tank in accordance with the measured volume of effluent to be treated. The mixing tank comprises a heater for maintaining the nitrified effluent temperature above 50 degrees F. An optional line filter can be added to the output of the system for further reducing organic nitrogen concentration. An alternate embodiment comprises passing the final denitrified effluent through a pump chamber for pumping of the effluent to a sand filter capable of reducing bacterial populations.

Abstract: A process for removal and recovery of nutrients and recycling of water from digested manure or other organic wastes. A first step involves separating waste from an anaerobic digester into digested liquids, digested solids, and biogas. A second step involves precipitating solids from the digested liquids. A third step involves stripping ammonia from the digested liquids. A fourth step involves injecting an exhaust stream of carbon dioxide drawn from the co-generator into the digested liquids to reduce the pH and raise the temperature of the digested liquid. A fifth step involves recycling the digested liquids back to the anaerobic digester for use in diluting in coming solid wastes. A sixth step involves passing the excess ammonia stripped from the digested liquid through the digested solids to recover nitrogen through aborption with the resultant digested solids being usable as a biofertilizer with a high nitrogen content. A seventh step involves capturing the biogas for use in a co-generation system.

Abstract: A process and apparatus for treating biosolids from biological wastewater treatment. The temperature of autothermal aerobic treatment of biosolids is controlled by sensing the oxidation/reduction potential of the solution and adjusting the amount of oxygen or biosolids supplied to the solution through a jet aerator (1) having a liquid header (3) for the recirculation of the solution and an air header (5).

Abstract: A Method of treating sludge prior to dewatering by mixing with the sludge a cationic metal in the form of an iron or aluminum slat along with a cationic polymer. The addition of the iron or aluminum salt substantially reduces the amount of polymer required for acceptable dewatering, thusly significantly reducing the cost of the dewatering process. The method is enhanced by subjecting the prior digested sludge to mesophilic aeration prior to the cationic metal salt and polymer being added.

Abstract: A method of treating wastewater sludge includes pumping, continuously, raw sludge into a first digester and treating the raw sludge at a specific temperature of between about 51° C. to 60° C.; transferring the treated wastewater sludge to a batch tank; treating the wastewater sludge in the batch tank, anaerobically, at a thermophilic temperature which is not more than 2° C. warmer than the specific temperature in the first digester; and disposing of the treated wastewater sludge as a Class A biosolid. A wastewater sludge treatment system includes a first thermophilic digester for treating raw wastewater sludge at a specific temperature in a range of between about 51° C. to 60° C., and discharging a treated wastewater sludge; a batch tank for receiving the treated wastewater sludge discharged from the first digester and for thermophilically treating sludge at a temperature in a range of between about 51° C. to 60° C. and not more than 2° C.

Abstract: A simple, reliable, inexpensive, and efficient anaerobic digester for treating organic wastes at a shortened residence time is described. The anaerobic digester is a multi-chambered digester that can handle wastewater and sludge in a large volume at a high flow rate. The digester also allows collection of methane gas for use as an energy source. The reactor is based on a sequential series of reaction chambers in a design that does not require internal moving parts. The volume of the chambers is adjusted to control the relative residence time of the waste to select an anaerobic microorganism group or groups that can efficiently digest the waste presented to that chamber. Under most conditions, no addition of bacteria is necessary. The digester works efficiently using microbes native to the waste material. After the reaction chambers and just prior to leaving as effluent, a settling chamber is located to reclaim the microbes and remove additional solids.

Abstract: A process for destroying pathogens in sludges/biosolids using rotor-stator technology to produce cavitation for pathogen destruction, combined with the feeding of lime or other alkaline material to induce heat and ammonia gas release. The combination of the rotor-stator with the lime produces higher temperatures than the addition of lime alone with a very high mixing efficiency giving maximum pH shift and ammonia release to all portions of the matrix. Overall, the process destroys the resistant stages of helminths or protozoan pathogens through a combination of cavitation with the increased heat caused by the rotor-stator/lime process, along with the locally released ammonia induced by the pH shift.

Abstract: This invention pertains generally to anaerobic digesters, and more particularly to a system and process that extends the range of acceptable biomass feedstock concentrations and provides pH process control of all known digestion processes: by the creation of a vacuum or vacuum retort in or before the digester that essentially acts to boil off excess liquid, thickening the liquor of the digester to an optimum value; and to control the pH of the various phases or stages of digestion by separating the component products of digestion and mixing or diffusing a portion of said component products into the mixing system of each phase of the process. A system and process: that produces a potable water effluent, clean commercially useful by-products, zero environmental emissions, a very positive ecological impact; and, that has the capability of being completely self powered plus providing energy back to the community or industry that supports or owns it.

Abstract: A method of treating sewage sludge comprises incubating raw sludge at a temperature in the mesophilic range to reduce the pathogen content of the sludge.

Abstract: A method for treating particulate biodegradable organic waste includes sizing the waste and adding a base prior to introducing the waste to a thermal hydrolysis reactor and hydrolyzing the waste at a temperature of about 130° C. or greater and a pressure greater than the saturated water vapor pressure to produce a slurry including solubilized organic material and residual solids. The solubilized organic material is separated from the residual solids using a liquid/solid separator and the solubilized organics are subjected to anaerobic digestion to produce a methane gas. The base is preferably potassium hydroxide (KOH) at a concentration of about 1%. The method may further include preheating the particulate biodegradable organic waste with latent heat of the separated solubilized organic material prior to thermal hydrolysis.

Abstract: A digester method and system for processing farm waste is provided. Specifically, the present invention provides a small-scale digester that processes approximately 0.1% to 10% of a raw waste stream at a temperature of approximately 100° F. The remaining 90% to 99.1% of the raw waste stream is directed to a waste lagoon without passing through the digester. Once the digester has processed the waste stream directed thereto, the processed waste is fed to the waste lagoon thereby inducing greater methane production.

Abstract: A process to recover energy, reduce pollution potential, and add value to organic waste such as animal manure is described. The process involves the anaerobic digestion of feedstocks, such as animal manure, at low to high temperatures in batch, semi-continuous or continuous reactors. The process makes use of existing handling and storage equipment at the farm and requires minimal supervision and skill by the operator. The system is not affected by high concentrations of volatile acids and ammonia or nitrogen. The productivity of the anaerobic digester system, in terms of methane gas production and quality, is exceptionally high. The anaerobic digester employs plural pressurizable anaerobic digesters connected in parallel. Consequently, the process is scaleable, low cost and does not interfere with regular farm operations.

Abstract: A method for incubation of nitrifying bacteria in a high concentration which are contained in small amount in activated sludge includes subjecting the activated sludge to nitrification and acclimation culture for about one to two months using a sludge-treated waste liquid such as dehydrate sludge filtrate and digested eluate under such a condition that the dissolved oxygen is 2-4 mg/liter, the pH is 7.5-8.5 and the temperature is 25-35° C. and, at the same time, constantly maintaining the pH within the pH range of 7.7-8.5 by addition of an incubation promoter comprising a mixture of sodium carbonate and sodium hydrogen carbonate.

Abstract: 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.

Abstract: An anaerobic process in accordance with the present invention includes the step of digesting an organic substrate in a first anaerobic reactor to provide reactor contents comprising solids and liquid products of digestion. The process also includes a step of removing a portion of the reactor contents, and a step of pasteurizing all or part of the removed reactor contents by direct contact with a hot or inhibitory fluid to cause pathogen destruction. The fluid may be in a gaseous or liquid phase and the fluid may have inhibitory effects which causes the organisms to undergo lysis.

Abstract: A method of treating a waste stream comprising feeding a waste stream into a reactor constructed and arranged for a fast start and maintained in a thermophilic temperature regime of between about 50° C. and 62° C. for a HRT of less than or equal to 48 hours, wherein the reactor contents are maintained at a pH less than or equal to 6.5; drawing a portion of the contents of the reactor and feeding the drawn contents into a second reactor which is maintained in a mesophilic temperature regime of between about 28° C. to 38° C. for a HRT of at least thirteen days; and replacing the contents drawn from the first reactor with more waste from the waste stream. Alternately, the waste stream may be initially treated in a mesophilic reactor, followed by treatment in a thermophilic reactor, or a single stage thermophilic reactor may be used.

Abstract: A process and composition for treating an animal waste in a waste holding facility to reduce sulfides and enhance efficient degradation of large amounts of organic matter with reduced odor. The process includes administering a probiotic material capable of promoting organic digestion to an animal and maintaining a sulfide gas concentration of less than 10 ppm from a waste produced by the animal. Maintaining a low sulfide gas concentration can be done by adding an innoculum of sulfide-utilizing bacteria to the waste produced by the animal.

Abstract: 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.

Abstract: Anaerobic digestion of a biomass system can be made more effective by intermittently introducing propane from an external source into said biomass system. The propane is preferably introduced into the biomass for about 20% to about 80% of any given time period.

Abstract: A waste treatment system comprises a first heat exchanger positioned before one or more reactors. The reactors discharge treated sludge to a second heat exchanger. The first and second heat exchangers share a heat transfer medium wherein the heat from the treated sludge is transferred to the incoming sludge. The treated sludge is cooled to reach an optimal temperature range before entry into a digester. The system also is adapted to allow a pipe cleaning device or “pig” to clean the heat exchangers by being forced through the heat exchangers by pressurized and pasteurized wastewater.

Abstract: A process to recover energy, reduce pollution potential, and add value to organic waste such as animal manure is described. The process involves the anaerobic digestion of feedstocks, such as animal manure, at low to high temperatures in batch, semi-continuous or continuous reactors. The process makes use of existing handling and storage equipment at the farm and requires minimal supervision and skill by the operator. The system is not affected by high concentrations of volatile acids and ammonia or nitrogen. The productivity of the anaerobic digester system, in terms of methane a gas production and quality, is exceptionally high. The anaerobic digester requires only a singe reaction vessel. Consequently, the process is low cost and does not interfere with regular farm operations.