METHOD FOR BIO-REFINING ORGANIC WASTE MATERIAL TO GENERATE UNNATURALIZED AND STERILE NUTRIENT PRODUCTSFIELD OF THE INVENTIONThis invention relates in general to the treatment of bio-refining of biological waste materials which denatures the pathogenic agents. More particularly, the invention relates to the processing of human, animal and plant waste materials, such as food waste and food processing waste from the domestic service and food businesses, diseased plants; meat and bones from the meat and fish packing plants; corpses of livestock, poultry and pets from farms, feeding and fattening sites, traces and veterinary clinics; and corpses, body parts, organs and tissues of animals classified or destined to be specifically destroyed by national, regional or community programs for the control of diseases; animal waste; municipal solid waste containing such waste material, and sewage sludge from wastewater treatment plants; of which all carry or could carry infectious agents of diseases transmissible to humans and animals. This material is processed in combination with organic fibrous material to create and produce sterile, denatured, environmentally safe and value-added plant and animal nutrient products.
BACKGROUND OF THE INVENTIONThe problem of treatment and disposal of municipal organic waste materials, food waste and animal waste, such as carcasses of animals and animals killed on the road, has been a challenge for nations, municipalities and industries since the beginning of civilization. There is a critical problem, which is growing, regarding the risks to human health due to an increasing variety of communicable diseases and pathogens including fungi, bacteria, viruses and transmissible spongiform encephalopathy (TSE). The recent crisis in Europe regarding TSE diseases such as mad cow disease has driven the need for a benign technology that will inactivate and denature these unruly protons (called prions). Traditionally, the processing of waste organic materials has involved the aerobic or anaerobic treatment and / or the digestion of the materials, and the stabilization of the digested materials. For black sewer water, additional steps are required, such as clarification and stabilization, using tanks and sedimentation tanks, and followed by dewatering in lagoons or with mechanical dewatering systems to give sewage sludge before final disposal. . Incomplete deactivation of pathogens in organic materials occurs mainly in the thermophilic stage during the digestion process. However, the conventional disposal or disposal procedure does not guarantee the sterilization of the pathogens present in organic materials.• of huge portions of land for ponds and sedimentation tanks or for sanitary landfills, as well as a period of weeks to months to complete, and presents air and water pollution, discomfort and other problems to the surrounding environment. Over the years a number of otherwaste treatment methods with varying degrees of success. These include the following types:Heat treatment It is a procedure used to disinfect and sterilize black water sludge. It is expected that during heat treatments, the enteric viruses in the waste materials will be deactivated at or above 70 ° C in accordance with the guidelines established by the United States Environmental Protection Agency. The method has been claimed as effective to destroy the majority of enteric pathogens in waste materials, especially sewage sludge, over a prolonged period.
Ionizing radiation It has been proven as a method to stabilize sewage sludge. 600-850 KeV gamma radiation can be used at 1 Mrad dosage levels to destroy the pathogens present in the• 5 sewage sludge. d0Co and 137Cs are the main sources of gamma radiation. Nordion International of Kanata Ontario, Canada, has developed a system that uses gamma radiation. However, this system requires high capital expenditures and, in addition, alters the physical and chemical properties of the sludge. Ultraviolet radiation and X-rays have also been used in effortsto disinfect waste materials, but results have shown that radiation is effective only for indicator microorganisms, such as coliforms, and are not effective for most pathogens such as gadia and cholera in vitro. These last agents present greater risks to human health. Incineration It is another procedure of treatment of organic waste in which temperatures are used above 1, 200 ° C to completely oxidize the biomass or the mud. If all the genetic materials associated with themicroorganisms are destroyed, the opportunity to recycle sterile organic materials increases the cost effectiveness of! treatment procedure. However, there is a need to dispose of waste from the incineration operation and incineration facilities are expensive. In addition, air emissions from incineration continue to be a major environmental concern.
Disinfection with chemicals • 5 This method has also been used to treat liquid waste. Compounds based on chlorine, ozone and other sterilizing substances are used to treat liquid waste. Chemical treatment can produce waste such as chlorinated hydrocarbons which by themselves have to be treated or discarded. F 10 Fumigation Another method that uses certain toxic gases to inactivate fungi, bacteria, viruses and other pathogens. Although a number of substances have been evaluated in terms of their effectiveness in disinfection or sterilization, theapplication of this technology requires great care to avoid human exposure to chemical, gaseous and toxic compounds through inhalation.
Composting is a method that uses aerobic biological activitiesimproved to stabilize organic waste. Compost formation procedures can vary with raw materials and technologies. There is a variety of composting devices that range from composting piles to automated compost formation chambers. An installation to make compost can take all types of organic materials and biomass and the operation can be continuous if a clogged flow process is designed. Composting can take from a few days to a few weeks to mature. The construction costs of a well-designed composting facility can be high and the operation requires a good emission control system to protect the health of the operators. The patent E.U.A. No. 3,385,687 demonstrates the preparation of compost in a digester from municipal organic waste milled. The ratio of nitrogen to carbon in the product converted to compost is at least 1: 20. The patent E.U.A. No. 3,533,775 analyzes the use of mixtures of sewage sludge and ground municipal waste to produce fertilizer.
As indicated in this document, the sewage sludge is mixed with municipal waste to provide a uniform mix. After this, the mixture of mud and ground waste is digested aerobically. The resulting materials are dried and ground for turf treatment and for other uses. The elimination of sewage sludge by the process of composting with the sludge and ammonia is shown in the patent E.U.A. No. 3442,637. The removal of sewage sludge with ground municipal waste is shown in the patent E.U.A. No. 4,586,659. The resulting mixture is sent to a compost facility and treated with aerobic bacteria to give a useful product as a soil conditioner. Composting is not an appropriate method to process animal carcasses, since compost production does not disinfect or sterilize the pathogens contained in the material to be processed. International patent application publication No. WO 93/08849, filed May 13, 1993, and which names as inventor theThe same inventor of the present invention describes a method for treating biomedical waste materials or other infectious waste materials associated with products of the plastic, paper, metal, glass, etc. type. Treated materials include packaging materials, syringes and utensils, tissues and waste from diagnostic and surgical procedures and cultures,• 10 bandages, rubber gloves, materials used in beds, diapers and sanitary napkins, etc. These infectious materials are granulated and subjected to a non-isotonic atmosphere at elevated temperatures and pressures, in which the non-isotonic atmosphere creates an osmotic shock that destroys the infectious agents. The resulting disinfected products include a componentliquid fertilizer and a solid waste component that is used as a compost material or solid waste that can be safely disposed of, but not as a nutrient. Sanitary landfill and soil dispersion are common. The elimination of animal by-products, carcasses of sick animals, cutsof skin, skulls and hooves from meat processing plants has traditionally been carried out by sanitary landfill. The manure is usually stacked and scattered over the fields. Although these materials can be useful as fertilizers for agriculture, stacking, sanitary landfill and soil dispersal of these materials create risks to human health. These include air pollution, and groundwater pollution caused by sewage water and provide the basis for growth for vectors that carry diseases such as flies. The disposal of animal carcasses or other infectious animal wastes, such as skin cuts, rotten eggs, and the like that probably contain infectious microorganisms, traditionally involves the landfill. This method, although effective in terms of costs in some places, has the disadvantages of polluting the environment and putting human health at risk. Sanitary landfill and soil dispersion are not effective in disinfecting or eradicating pathogens contained in municipal organic waste and animal waste, in sewage sludge and other organic waste, and require prolonged periods and large areas of land or land. lagoons. In addition, the products of the prior art treatments have a bad odor and are not sterile. Sterility is desired due to the typical presence of pathogenic organisms in the materials. The final products need to be sterile before being put on the market. With the outbreak of transmissible spongiform encephalopathy (TSE), particularly bovine spongiform encephalopathy (BSE) and virulent diseases in Europe, the inactivation of pathogens is even more necessary. Animal waste, such as waste, manure and carcasses, are subject to carry infectious agents including fungi, bacteria, viruses and prions associated with BSE, TSE, etc. Therefore, there is a need for methods to process and / or remove municipal organic waste materials, sewage sludge, and animal waste without the disadvantages of the prior art. The present invention overcomes all the disadvantages and problems of• the prior art in efficiently treating and processing the various types of organic waste products discussed above, in combination with a fibrous material, which may be, but not necessarily, obtained from municipal solid organic waste, which It is also becoming an environmental nuisance as landfills are arrivingto its capabilities and the production of waste is increasing. The present invention involves refining and denaturing infectious organic waste materials and using organic fibrous materials such as newspapers, corrugated cardboard, or even organic fibrous waste materials such as waste packaging materials, or dry plant products. The method ofThe biorefining of the invention to treat a wide variety of waste materials produces sterile, inactive or denatured and environmentally safe final products, such as conditioners or soil fertilizers or other useful materials. The invention uses saturated steam at elevated temperature and at elevated pressure during the denaturing andsterilization to denature all potentially pathogenic agents. The vapors or odors are evacuated from the upper space in the treatment vessel, condensed and purified, using dry and wet scrubbers commercially available from companies such as American Air Filter, Louisville, Kentucky, E.U.A. The treatment time necessary to achieve these results is short, being a matter of hours, particularly when compared to the prior art technologies used for waste processing which can take days.
BRIEF DESCRIPTION OF THE INVENTIONThe invention effectively addresses the problem of environmentally safe treatment and disposal of organic waste material through a biorefining process that transforms infectious material, such as household food waste, waste meat and bone waste from industrial industries. food processors, carcasses of dead and sick animals from all sources, dehydrated sewage sludge, and fibrous organic waste material, in denatured products, with added value. As used in the present invention, the term "infectious organic waste material" means organic waste material that is actually or potentially infectious, in the sense that it actually or potentially includes any type of pathogen that can cause disease. or ailments in a human or animal. Therefore, the term includes organic waste materials that are expected to be infectious because some samples have been found to contain pathogens. It is not necessary that the material is actually evaluated in advance to determine if it is infectious or not. As used in the present invention, the term "denaturalize" and its grammatical equivalents, means both to sterilize and inactivate pathogens in such a way that they are no longer harmful to humans or animals. This term is chosen to be used in the present invention in the same way as it is applied in microorganisms, such as fungi, bacteria or other microorganisms that can metabolize and reproduce themselves; viruses which can be seen either as extremely simple microorganisms or as extremely complex molecules that typically contain a protein coat that surrounds a nucleus of RNA or DNA of genetic material but with a non-semipermeable membrane, which can grow and multiply only in living cells; and also prions, such as TSE, BSE and Scrapie, which are proteins, instead of microorganisms, which nonetheless interact with the human and animal biochemical compounds to form a template or pattern that causes disease or illness. Therefore, the term "denaturing" is used in the present invention as a term that encompasses rendering any of these harmful pathogenic agents non-harmful according to the method of the present invention, regardless of whether the pathogenic agent is converted into non-harmful by sterilization, inactivation or any other technique within the method of the present invention.
A method for converting infectious organic waste material that is selected from the group consisting of food waste, food processing waste, carcasses, body parts, organs, animal tissues and mixtures thereof into a nutrient product for plants or animals solid, denatured, comprising (a) grinding absorbent organic fibrous material from a source other than that of infectious organic waste material; (b) mixing the organic fibrous material with the infectious organic waste material to form a reaction mixture; (c) heating the reaction mixture in a hyperbaric reaction vessel at an elevated temperature and at a superatmospheric pressure for a time sufficient to create saturated steam, to hydrolyze the organic fibrous material and convert the reaction mixture into a plant nutrient product or substantially denatured animal containing inactive pathogens; (d) releasing the vapor from the hyperbaric reaction vessel to a condenser; (e) dehydrating the denatured plant or animal nutrient product in the hyperbaric reaction vessel to produce a solid, free-flowing, denatured, plant nutrient or animal product; and (f) discharging the solid, dehydrated, free-flowing denatured nutrient from the hyperbaric reaction vessel. The dehydrated and denatured products produced in the invention can be used in agricultural, industrial and commercial applications, such as fertilizers, soil conditioners and as ingredients for animal feed. The denatured vapor can be recovered and condensed as a denatured liquid that can be used in applications such as crop irrigation or for the production of liquid fertilizer. The invention uses existing and proven equipment for the system of bio-refining and processing of organic waste materials. The main components of the system include storage tanks, mechanical size classifier, a high pressure steam boiler, a high pressure reaction vessel, a condenser, an environmental scrubber tower, conveyor belts and a pelletizing apparatus.
DETAILED DESCRIPTION OF THE INVENTIONIn general, this invention relates to the treatment of infectious organic waste material, including waste material from animal and human plants, such as food waste and food processing waste from domestic and food service businesses; diseased plants, such as those infected with fungal diseases; meat and bones from the meat and fish packing plants; corpses of livestock, poultry and pets from farms, feeding and fattening sites, traces and veterinary clinics; and corpses, body parts, organs and tissues of animals classified or destined to be discarded in a specific way by national, regional or community disease and control programs;animal waste; and municipal solid waste that contains such waste materials; and sewage sludge from wastewater treatment plants; the treatment of this infectious material according to this invention denatures the material, making it non-infectious. A reaction mixture is prepared, including infectious organic waste material and milled organic fibrous material which can be obtained from the organic fibrous portion of the municipal waste, and optionally, an oxidizing agent. The reaction mixture is treated with saturated steam under superatmospheric pressure at elevated temperature to give denatured and value-added granular end products. Although any type of infectious organic waste material can be treated using this invention, it is particularly effective in treating animal wastes which include lipids in amounts of the order of up to about 30% by weight. Such animal waste material is difficult to treat because the lipids create a sticky mass that resists effective and efficient treatment and handling. The corpses, body parts, organs or tissues of animals that could be treated in accordance with the present invention include those of typical cattle including cows, sheep, goats, pigs, horses and poultry including chickens, geese and ducks, and virtually any another animal from any other source whose corpses, body parts, organs or tissues should be discarded. Small whole carcasses or large ground carcasses are mixed with organic fibrous material and heated with saturated steam at elevated temperatures and at peratmospheric pressures for a sufficient time to provide denatured final products. Large carcasses must be ground or shredded to particle sizes with an average maximum dimension of approximately 50 mm. Crushing to the proper size should be done using any appropriate equipment, such as hammer mills or shredders with shear stress. The dimensioning must be done in a closed environment to avoid the emission of pathogens in aerosol to the external environment. Any of the aerosol odors or pathogens can be treated using an air filtration system, such as those manufactured by Durr Industrial Products, Inc., Plymouth, Mich., E.U.A., or American Air Filter. The invention is directed to the denaturing of infectious organic solid waste materials, excluding plastics, rubbers, metallic materials, glass, concrete and other durable materials. Therefore, the invention is directed primarily to the denaturation of infectious animal waste and, in the background, to infectious plants and other debris as indicated above. Raw sewage sludge or water that has been removed from the water that can be processed according to the invention typically, but not exclusively, has about 2% by weight to about 25% by weight of solids and about 75% up to about 98% water, preferably above 3% solids. The low solids sludge is initially dehydrated using a commercially available press filter such as that sold by Micronics, Inc., Portsmouth, New Hampshire, E.U.A. The dewatering of the sewage sludge in the press filters can be used to increase the solids content in the sludge by at least up to about 10%, and preferably at least 25%. It is preferable to treat dehydrated sludge in the reactor, since a smaller amount of water is heated or evaporated, the salts present in the sludge dissolved in the water are reduced in the final product, and the time required to denature and dehydrate the sludge is reduced . The fibrous organic material used in the method of the present invention is necessary so that a denatured product which is a free flowing solid product can be made, which can be easily removed from the reaction vessel using, for example, an endless screw. The organic fibrous material useful in the invention is cellulose-containing material and lignin-containing material which has a moisture content of not more than about 40% by weight. In this way, the organic fibrous material is sufficiently dry to absorb water and other liquid components, such as blood, or the infectious waste organic material being treated, as well as the lipid components of the infectious waste organic material, including fat and other types of lipids. It would be impossible to produce the denatured product, with added value, without using dry fibrous organic material to absorb the liquid and lipid components of the infectious waste organic material, as a free flowing solid product, such as the one desired in accordance with the present invention. The organic fibrous material used in the present invention may be a relatively pure material purchased or in some other way purchased for use in the present invention as described above. However, if desired, the organic fibrous material can include or be obtained from organic fibrous waste material, such as municipal waste material. The organic fibrous portion of municipal waste material useful in the invention includes cellulose and lignin waste materials, for example, newspapers, corrugated cardboard, mixed waste packaging material, and other organic fibrous materials. Other organic fibrous materials useful in the present invention include, for example, hay, straw, such as oat straw or wheat straw, corn husk and moss, as long as these materials do not exceed the maximum indicated moisture content. Combinations of the different types of organic fibrous materials can be used in the present invention. The dried fibrous material is milled to a size having a maximum average dimension of about 1 mm which can be used as a filtration and retention medium. Well-known devices such as hammer mills and granulators can be used to grind the fibrous material. The grinding increases the surface area of the fibrous organic material making it more capable of absorbing the liquid and the lipid components of the organic material of infectious waste. The milled organic fibrous material should have a maximum moisture content of not more than 40% by weight, and preferably contain no more than about 25% water, and even more preferred, no more than about 15% water. tffc The reaction mixture comprising the organic material ofinfectious waste and optionally milled organic fibrous material may include an oxidizing agent. The oxidizing agent increases the denaturation of the infectious waste organic material. Preferably, the oxidizing agent used in the present invention contains or adds to the desired product some nutritional value. Oxidizing agents having nitrate anions are preferred,f 10 sulphate or phosphate, or mixtures thereof. The cations for oxidizing agents having such anions are preferably ammonium, sodium, potassium or mixtures thereof. The oxidizing agents useful for treating infectious waste materials are water soluble, have a high oxidation potential, and are stable under the conditions used to treat the reaction mixture.
Preferred examples of oxidizing agents include ammonium nitrate and potassium nitrate. Examples of other oxidizing agents include, but are not limited to, sulfates such as ammonium sulfate and potassium sulfate and nitric acid and sulfuric acid. Ammonium nitrate is currently the most preferred oxidizing agent and ammonium nitrate in the form of chemical fertilizer classified as 34-0-0 (N-20 P2O5-K2O) is an especially useful source. However, ammonium nitrate should not be used, if the final product is used as animal feed. In general, when preparing reaction mixtures for treatment to obtain a denatured final product that is used as a soil conditioner or as a plant nutrient, the oxidizing agent is added to the infectious waste organic material in an amount sufficient to significantly increase the destruction of pathogens, or to increase the product to a specific nutrient level. It is expected that an oxidizing agent accelerates the cutting of bonds in organic compounds, particularly those of long chain substances. The amount of oxidizing agent may vary, depending on the type of oxidizing agent chosen and the nature and type of the organic waste material to be treated. In general, it is preferred that the oxidizing agent be added to the infectious waste organic material in an amount that provides a weight ratio of oxidizing agent to infectious waste organic material from about 1: 30 to about 1: 10. This weight ratio works well when the oxidizing agent is ammonium nitrate and when the infectious waste organic material is dewatered sewage sludge or animal waste of the type discussed above, for example. Also as indicated above, ammonium nitrate should not be used if the final denatured product produced by the method of this invention is to be used as animal feed. Therefore, typically, but not exclusively, the waste material treated using ammonium nitrate as the oxidizing agent could be used as a soil conditioner and fertilizer or as another such agricultural product. The infectious waste organic material, with or without an optional oxidant, together with the milled organic fibrous material, provides a reaction mixture. The order of addition of the starting materials does not matter. If an optional oxidizing agent is used, it is preferred, but not essential, to mix the oxidizing agent and the infectious waste organic material before combining the mixture with the ground fibrous material or before adding the ground fibrous material to the mixture. Additionally, the materials can be mixed in advance and then charged to a hyperbaric reaction vessel, or the starting materials can be added as separate ingredients in the hyperbaric reaction vessel, as long as the reactor includes stirring or mixing elements. , such as an arrow with stirring blades extended so that the reaction mixture can be mixed into the reaction vessel. The reaction mixture typically has a weight ratio of infectious waste organic material to ground organic fibrous material of from about 1: 4 to about 4: 1 and preferably from about 1: 3 to about 3: 1. The proportions of infectious waste organic material and milled fibrous organic material in the reaction mixture may vary according to the use of the denatured final product. For exampleWhen the denatured product is intended to be used as a fertilizer, the weight ratio of infectious organic waste material to milled fibrous organic material can be about 4: 1. When the denatured final product is intended to be used as a soil conditioner, the weight ratio of the infectious waste organic material preferably enriched in nutrients to the milled fibrous organic material may be about 1: 3. In the case where it is intended to use the denatured end product for animal feed, the weight ratio of waste of animal origin, such as carcasses of animals, to milled fibrous organic material can be from about 3: 1 to about 1: 1 to ensure the absorption of lipids, and especially that of fatty materials by the fibrous organic material. Those skilled in the art, in view of this disclosure will be able to determine other useful relationships of organic material from infectious waste to milled fibrous organic material to provide denatured products useful in other specific applications. After the reaction mixture is in the hyperbaric reaction vessel, the vessel is completely sealed, and then heated to a temperature between about 180 ° C and about 200 ° C, preferably between about 180 ° C and about 190 ° C and more preferred, about 185 ° C. Due to the aqueous nature of the reaction mixture, saturated steam is generated in the reaction vessel at a pressure of about 9.85 to about 14.06 kg / cm2, preferably about 10.55 kg / cm2. If desired, steam from an external source, such as a boiler or other steam generating equipment, can be injected into the reaction vessel to accelerate heating and pressurization within the vessel. The heating of the reaction mixture and its consequent exposure to saturated steam at elevated pressure is continued for a period sufficient to denature the reaction mixture.
Typically, this period is from about 20 to about 40 minutes, preferably about 30 minutes, but could be longer, in the order of about 60 minutes, if desired. The reaction mixture treated in the reaction vessel must be stirred throughout the treatment process by means of an internally heated vane stirrer installed in the reaction vessel. The agitator helps provide consistent mixing and mixing of the reaction mixture, as well as preventing the accumulation of liquid near the bottom of the container. The agitator also facilitates the uniform exposure of the reaction mixture to saturated steam at high temperature and at high pressure, and breaks the large pieces of waste material into smaller pieces. After completing the reaction cycle, the reaction vessel is depressurized, preferably in a short time of about 5 minutes, by opening a valve connecting the reaction vessel to a condenser. During the depressurization step, the sudden initial drop in pressure increases the destruction of the cellular components that remain in the reaction product. The denatured vapor passes through a condenser and is collected as a liquid condensed material to ensure that the vapor is not released into the atmosphere. The vapor above the liquid in the condenser can be treated to remove malodorous compounds using appropriate purification equipment such as those commercially available from AmericanAir Filter and Durr Industries, Inc.
The resulting denatured reaction product is dehydrated to form a free flowing solid that can be easily removed from the reaction vessel using an endless screw, for example. A product as such also makes handling, storage and shipping easier and less expensive and gives the end product an increased shelf life. While and after the reactor is depressurized during a typical cycle of about 2 hours to about 4 hours, the reaction vessel and the stirrer are heated to accelerate the drying and dehydration of the denatured product within the reaction vessel. Also during this dehydration cycle, the steam is evacuated to the condenser. The vacuum also accelerates drying. When the moisture content of the resulting product is about 10% or less, drying is considered finished. After recovering it from the reactor, the dehydrated, denatured ground product is transported to a cooling area. The air in the cooling area can be cleaned to remove malodorous compounds. Proper purification equipment can be readily obtained commercially, for example, from American Air Filter and Durr Industries, Inc. By means of flexible processing conditions, the invention provides a variety of useful end products. For example, by extending the reaction time from about 30 minutes to about 60 minutes when treating mixtures of black water sludge and municipal waste cellulose ground at about 10.55 kg / cm2 and about 185 ° C, significant hydrolysis can be achieved. of cellulose and hemicellulose contained in municipal waste material. These resulting short chain carbohydrates and reducing sugars increase the value of the final products, since these substances improve the availability of nutrients and the digestion capacity of the fibrous substances and make the odor of the product more pleasant. In addition, the process accelerates the hydrolysis of the fibrous material. Without wishing to be limited to the theory, it is believed that the organic material of infectious waste, when mixed with the fibrous material• Organic milled, results in the formation of a thin bio-film containing microorganisms or other pathogenic agents from the infectious waste material on the ground fibrous particles. It is believed that the porosity of the ground particles provides a capillary action by means of which the fibers absorb free water, organic compounds in traces, lipids andtrace elements from the infectious waste material and make the denaturation process more efficient. The physical and chemical processes thatF is believed to be responsible for these reactions are due to the formation or breakdown of hydrogen bonds, complex formation and chelation. In addition to generating denatured products, the invention substantially eliminates unpleasant odors associated with the removal of infectious waste organic material such as sewage sludge and waste material of animal origin. Without wishing to be limited by theory, it is believed that the elimination of these odors is due to a reduction in the amount of odor production sources generated from microbial activities, together with the production of compounds similar to those in sugars or molasses. which have a more pleasant smell. It is believed that these compoundshave a pleasant smell are formed due to the hydrolysis of cellulose, the production of reducing sugars, and the oxidation of organic compounds. The removal of unpleasant odors is also aided by the purification of the steam from waste gases containing carbon dioxide, methane, and volatile sulfur and amine compounds. The invention therefore eliminatessubstantially the emission of malodorous gases to the environment. Infectious waste materials, when processed according to the invention, are sterile and inactive. All fungi, viruses, bacteria (including bacteria that form spores) and other pathogens are completely inactivated and become non-viable and prions are destroyed. Therefore, the risks to human and animal health and the responsibilities associated with the handling of materials are significantly reduced,} storage or reuse. The particular type of equipment used in the present invention is not important, as long as the equipment can perform the operations indicated on the materials to be treated. Therefore, for example, any type of milling device can be used to reduce the materials to be treated to the appropriate particle sizes as discussed above. In addition, the hyperbaric reaction vessel can be of any size and shape as long as the indicated vapor pressure and temperature ranges are maintained. The pressurized container can be heated in any appropriate way, including electrical conductance or inductive heating, by• 5 heat supplied from fossil fuel burners, steam jacket equipped outside and the like. The operation of the invention can be automated. Said automated equipment could include various remote or automatic controlled unloading and entry doors, heaters, conveyors, units• 10 condensation, gas scrubbers and all associated sensors and control equipment, all of which are preferably controlled by computer in a manner similar to that used with many other automated industrial operations. A skilled computer programmer could easily program a digital computer to monitor and control substantially all aspects of the system in the present invention, as long as the appropriate predetermined parameters of the operation are provided by the programmer. The invention will be described in detail below with reference to the following specific, non-limiting examples. Unless stated otherwise, all percentages are by weight and all temperatures are in Ceisius degrees. In the following examples, a stainless steel hyperbaric reactor with an internal volume of up to 10 cubic meters and that can withstand a maximum pressure of 17.58 kg / cm2 was used. The container includes a loading door valve to receive the organic waste material infectious such as waste materials of animal origin, the fibrous organic material, the oxidizing agent and other supply materials. The reaction vessel includes a heated paddle stirrer to increase mixing and provide uniform pressure and temperature conditions throughout the volume of the reaction mixture during the processing time. The reaction vessel was heated with an external steam jacket and an inlet for the injection of steam into the container is also provided. A discharge port valve is provided in the reaction vessel to discharge the denatured product.
EXAMPLE 1 The treatment of reaction mixture of sewage sludge and municipal waste cellulose ground materialIn a pilot-scale study, approximately 135 kg of fibrous organic material was sprayed as municipal cellulosic waste material, mainly paper, magazines and cardboard, to an average maximum dimension of less than about 8 mm using a hammer mill. The pulverized cellulosic waste material was supplied to the reaction vessel. The pulverized waste material has a water absorption capacity of about 400% up to about 600%. Approximately 129 kg of sewage sludge (approximately 3% solids), approximately 36 kg of waste material of plant and food origin and approximately 5.1 kg of NH4NO3 were added to the vessel and mixed with the municipal fibrous waste material to provide a reaction mixture. The charging time was approximately 15 minutes. While the ammonium nitrate was mixed with the sewage sludge before the mixture was transported to the reaction vessel, the oxidizing agent could be added after the sludge and the organic fibrous material are added to the reaction vessel, and in some cases, the oxidizing agent can be removed (for example, for the production of animal feed, ammonium nitrate should not be added). After loading the reaction mixture, the reaction vessel was sealed. The reaction mixture to the vessel was constantly stirred by a paddle stirrer internally heated inside the reaction vessel. Agitation or continuous mixing through the process to ensure complete dispersion and absorption of liquid and the absence of any accumulation of liquid at the bottom of the container. The loaded reaction vessel was heated with steam jacket coils to 185 ° C. Then steam was injected into the steam vessel for a period of about a few minutes to achieve a pressure of 10.55 kg / cm2 and a temperature of 185 ° C inside the vessel. These pressures and temperatures were maintained for 30 minutes. After this, the reactor was depressurized for a period of 5 minutes by opening a depressurization valve. The steam escaping from the reactor during depressurization condensed to form a denatured liquid concentrate. The residual steam in the condenser was passed through an environmental scrubber before being released into the atmosphere. The condensed material was returned to the collection tank of or the primary sedimentation tank of the treatment system of• Wastewater which was used to improve by raising the temperature of the wastewater and thus increasing the microbial activity in the sedimentation cistern. After depressurizing, the final product denatured in the form of particles is dehydrated in the reaction vessel heated by the• 10 spirals heated with external steam and the blades heated to a moisture content of approximately 10%, over the course of approximately 4 hours. The denatured material in the form of particles was cooled and transported from the container discharge port. The download procedure took approximately 20 minutes. 15 EXAMPLE 2 Test of effectiveness against pathogensTo gauge the degree and efficiency of sterilization that canachieved by the present invention, the sample was seeded with some typical enteric pathogens. These included Escherichia coli, Enterococcus faecalis, Aspergillus niger, Polio virus type 3, Pseudomonas aeruginosa andBacillus stearothermophilus. After sowing, it was found that the plate count of heterotrophs (HPC) is greater than 1.9 x 109 cfu per 100 g in the mixture of untreated sewage sludge, municipal waste cellulosic ground and ammonium nitrate in proportions similar to example 1. f The mixture was then treated as described in example 1 above. The results taken at the end of the 30 minute treatment cycle are shown in table 1. The tests were performed following the recognized standard. "Diagnostic Procedure for Viral, Rickettsial and Chlamydial Infections, "American Public Health Association - 5th Edition, Eds. Edwin Lennette and Nathalia Schmidt, American Public Health Association, Washington, DC (1979).
TABLE 1Pathogens in mixtures of treated and untreated waste material and inCondensed material treatedUnprocessed Mixing Condensate treated treated mixture pathogens *** Routine sample, average results of 30 samples (90 tests) Total coliforms > 230 per 100 g < 11 per 100 g < 1.1 per 100 ml Fecal Coliforms > 230 per 100 g < 11 per 100 g < 1.1 per 100 ml HPC * 1.3 x 107 per g < 100 per g 38 per ml ASB ** > 230 per 100 g < 11 per 100 g < 1.1 per 100 mlSown with suspension of E. coli, average results of 18 samples (54 tests) E. coli > 16,000 per 100 g < 11 per 100 g < 1.1 per 100 ml HPC 1.9 x 107 per g < 100 per g < 10 per mlSeed with suspension of E. faecalis, average result of 12 samples (36 tests) Polio virus type 3 isolated Isolated isolated Sown with suspension of Ps. Aeruginosa, average result of 6 samples (18 tests) Ps. Aeruginosa > 16,000 per 100 g < 11 per 100 g 1.1 per 100 ml HPC 3.0 x 107 by < 100 per g 3.8 x 103 per mlSown with suspension of B. stearothermophilus. average result of 6 samples (18 Li tests) B. > 9,000 per 100 g < 11 per 100 g < 1.1 per 100 ml stearothermophilus 4.6 x 106 per g < 100 per g 100 per ml HPC Sown with a suspension of A. niger, average result of 12 samples (36 tests) A. niger isolated not isolated not isolated HPC 5.6 x 107 by < 100 per g 140 per ml* Heterotrophic plate count ** Aerobic sporulated bacilli;*** With respect to the HPC result in the samples of theCondensate, the sampling site to take the condensate samples was a plastic hose outside the building and was probably in contact with the outside contamination, or had an accumulation of microorganisms in the pump. Therefore, the ten minute wash may not have been enough.
• When taking this type of samples for evaluation, the risk of external contamination is always a concern. Since no other contamination was detected in these samples, ie, coliforms, it could be that the sampling procedure was the cause of the low counts detected in a few of the samples of condensed material, rather than inadequate treatment by the bioreactor. • 10 As indicated in the results of Table 1, the quantities of the tested pathogens contained in the final product in the form of treated particles and in the liquid condensed material were either below the detection limits for the methods used or were substantially reduced compared to the amounts of such pathogens for the untreated mixture.
This demonstrates that the invention is highly effective in destroying the tested pathogens.
EXAMPLE 3 Analysis of Selected Gases As previously indicated, the present invention effectively eliminates the unpleasant odors associated with sewage sludge and mixed solid organic waste materials. The elimination of odor is attributed to a decrease in the sources of odor production by microbial activity. In addition, the process produces compounds that have relatively pleasant odors, such as those of the sugars or molasses produced as a result of cellulose hydrolysis, the production of reducing sugars and the oxidation of organic compounds. An environmental scrubber tower helped eliminate or significantly produce levels of carbon dioxide, methane and volatile sulfur compounds, and possibly amine compounds in the vapors. The residual steam present in the upper space of the condenser was passed through an environmental treatment tower before being released to the atmosphere. The purified gases contain only trace amounts of methane and sulfur compounds which were slightly above the limit of detection and a low level of CO2 as indicated in Table 2 below. At these low levels, these gases do not present problems for the environment.
TABLE 2 Gaseous components in the upper space of the reaction vesselDebug C02 Methane (ppm) TSC * (ppm) Test 1 Before 10.77 40 23.6 After 2.48 < 30 1.2 Test 2 Before 10.18 30 24.9 After 1.95 < 30 5.3 Test 3 Before 20.72 100 27.9 After 4.01 25 0 Test 4 Before 4.22 55 17.4 After 0.72 6 4.2 Test 5 Before 6.95 140 3.7 After 0.68 15 0Total sulfate compoundsEXAMPLE 4 Analysis of final product in the form of particles for certain applications in landUsing the same procedures as in Example 1 and the similar proportions of the materials, but without adding NH4N03) the waste materials were transformed into useful final product. The denatured solid end product is environmentally safe and has a number of uses. The product has a number of uses as soil additives and plant nutrients. The final solid product, as shown in Table 3, has nutrient levels that can make it very useful for a variety of agricultural applications. This particular final product was made from a mixture of food waste, sewage sludge, and municipal solid waste including milled fibrous organic material. Standard procedures for analytical work were followed, and analyzes were performed by certified private laboratories. The product was developed using a pilot plant facility.
TABLE 3 Some nutritional parameters of the final productEXAMPLE 5 Processing of chicken carcassesApproximately 3.2 kg of complete chicken carcasses, 0.3 kg of powdered telee directories and cardboard, and 1.5 kg of alfalfa meal pellets were placed in a sealed laboratory reaction vessel, similar to that of the pilot facility except that the size was more small and that the reaction chamber and the boiler were combined. The vessel was heated externally to a temperature of 185 ° C at a pressure of 10.55 kg / cm 2 and the temperature and pressure were maintained for a period of 30 minutes while the materials in reaction were constantly stirred. The vessel was then depressurized as in Example 1. The resulting solid product was dehydrated for a period of about 2 hours to give a solid denatured product having a moisture content of less than 10%. This denatured product has value as a food product for animals as reflected in the nutritional values shown in table 4.
TABLE 4 Nutritional values of the product from Example 4These nutritional values suggest that the product can be used as feed or food supplements for poultry and / or livestock since it can supply these animals with sufficient energy (fats), amino acids and higher fibers in various ways.
EXAMPLE 6 Processing of livestock carcasses and mixed organic waste materialsUsing the pilot plant facility, the present invention was used to process animal carcasses and mixed organic waste. In a typical test, the feeding materials have the following composition:These materials were placed in the reaction vessel used in example 1. The vessel was then sealed and heated with steam to a temperature of 185 ° C at a pressure of 10.55 kg / cm2. These conditions were maintained for a period of 30 minutes while the materials in the vessel were under constant agitation. The container was then depressurized as in example 1. It was found that the resulting denatured solid products had excellent properties to be used as a food and / or animal supplement.
The present invention provides distinct advantages over the prior art treatments of waste materials of animal origin and municipal solid waste and dewatered sewage sludge. All the reaction products were denatured with saturated steam at elevated temperature and pressure. Pathogens with infectious diseases were effectively denatured by oxidation and hydrolysis under the various reaction conditions. Unpleasant odors were reduced with the method of the present invention, enclosing the system, and using devices for odor control. The operators do not have direct exposure to the materials once they are supplied to the reactor. Powdered or ground fiber acts as an absorbent to retain free water, and acts as an absorbent for organic compounds, including blood and lipids such as animal fat which adversely affects other treatment systems, and trace metals. The particulate matter and the condensate were denatured to the extent that all fungi, bacteria (including spore-forming bacteria), viruses and other pathogens were completely inactivated and rendered non-viable during denaturation. Therefore, the risks to human salience and the responsibilities associated with the handling, storage or recycling of materials containing pathogens were significantly reduced. In addition to treating organic material from primary infectious waste, by recycling and treating fibrous organic materials from municipal solid waste material, the volume of municipal solid waste can be significantly reduced. It is estimated that municipal solid waste contains at least 40% recyclable organic fibrous materials and degradable organic substances. These can be used or processed in the present invention and help to release the load on landfills. It is believed that the method of the present invention stimulates the hydrolysis of cellulose materials and produces short chain substances which can be more readily digested by microorganisms. Hydrolysis occurs in the vessel as a result of grinding the fibrous organic material into small pieces and subjecting them to high temperatures and pressures and to active radicals. The presence of oxidants, such as ammonium nitrate, accelerates hydrolysis and oxidation procedures. The process is aided by the formation of free protons and / or radicals during the dissolution of the oxidant, such as ammonium nitrate. The method of the present invention provides significant savings in time and space compared to the prior art methods. The complete treatment process, from the supply of raw materials to the reaction vessel, through and including dehydration and pellet conversion operations requires approximately 5 hours. This means that the entire procedure can be accomplished in a work shift. Because the treatment time is short, large areas of land are not required as the prior art (for example, to form gates), and the treatment times are reduced from weeks and months to a few hours. In general, the present invention provides a very safe, efficient and effective system for treating organic material from infectious waste.