Urban waste recycling system and method

Abstract

The invention discloses an urban waste recycling system and method, and relates to the technical field of environmental protection and resource reutilization, and the method comprises the steps of waste centralized collection, filtration, waste liquid circulation, sorting, physical recovery, chemical recovery, biotransformation, energy recovery, material restoration and special resource recovery. The waste centralized collection is connected with the filtration; the filter is respectively connected with the waste liquid circulation and the sorting; sorting is connected with physical recycling, chemical recycling, biological conversion, energy recycling, material repairing and special resource recycling, and the method integrates the sorting technology, the physical recycling method, the chemical recycling process and the biological conversion process, so that valuable substances in urban waste can be efficiently separated out and reused; the raw materials can be converted into high-quality raw materials and enter a production cycle again, so that the resource recovery rate is increased, the quality and market value of the recovered materials are improved, and sustainable utilization of resources is promoted.

Description

Technical Field

[0001] The method belongs to the technical field of environmental protection and resource recycling, and in particular relates to a system and method for recycling urban waste. Background Art

[0002] With the acceleration of urbanization and population growth, the amount of urban waste has increased dramatically. These wastes include domestic waste, industrial waste, construction waste, etc., which are of various types and huge in quantity. Traditional waste disposal methods, such as indiscriminate discharge, landfill and incineration, not only occupy a large amount of land resources, but also may cause serious air, soil and water pollution to the environment, and it is impossible to recycle the waste. Therefore, developing an efficient and environmentally friendly urban waste recycling system and method to effectively classify, recycle and reuse these wastes to solve this problem has become an important issue at present. Therefore, we propose an urban waste recycling system and method.

[0003] Method content

[0004] The purpose of this method is to provide a system and method for recycling urban waste. By integrating advanced sorting technology, physical recovery methods, chemical recovery processes and biological conversion processes, valuable substances in urban waste can be efficiently separated and reused, and can be converted into high-quality raw materials and re-enter the production cycle, solving the problem of traditional waste treatment methods such as indiscriminate discharge, landfill and incineration, which not only occupy a large amount of land resources, but also may cause serious air, soil and water pollution to the environment, and cannot recycle the waste.

[0005] To solve the above technical problems, this method is implemented through the following technical solutions:

[0006] This method is a system and method for recycling urban waste, including centralized waste collection, filtration, waste liquid circulation, sorting, physical recovery, chemical recovery, biological conversion, energy recovery, material repair and special resource recovery;

[0007] The centralized waste collection is connected with filtration; the filtration is respectively connected with waste liquid circulation and sorting; the sorting is respectively connected with physical recycling, chemical recycling, biological conversion, energy recycling, material repair and special resource recycling.

[0008] As a preferred technical solution, the centralized waste collection is responsible for deploying garbage bins of different classifications in various corners of the city. These garbage bins make preliminary distinctions between the garbage put in, and the types are divided into recyclables, hazardous waste, wet garbage and dry garbage. Special waste transport vehicles are used, and different carriages are configured according to different types of waste to avoid secondary pollution caused by mixed transportation, and the waste is put into the waste collection point;

[0009] The filtration is responsible for filtering dry and wet wastes, and performs preliminary filtration through roughening, grilles, rotary screens or grit chamber equipment to remove large particles of impurities and suspended matter, and separate wastes from liquids;

[0010] The sorting is responsible for carefully classifying the waste mixed in the waste that does not belong to this category by using an automated sorting line in the sorting center, so that the various types of waste can be effectively separated.

[0011] As a preferred technical solution, the waste liquid circulation method after filtration is:

[0012] Step 1: Adjust different pH values ​​according to different usage requirements. For domestic water, including drinking water, bathing water, and daily water, the appropriate pH value range is usually between 6.5 and 8.5. The water quality within this range is safe for human health and also meets relevant health standards;

[0013] For industrial cooling water systems, the appropriate pH range is usually between 7.0 and 8.5. pH values ​​within this range prevent scale formation and reduce corrosion to metal pipes.

[0014] For boiler feed water, pH value control is more stringent and usually needs to be maintained within a specific range, such as 9.0 to 10.0, to ensure safe operation of the boiler.

[0015] Step 2: Add a coagulant, such as polyaluminium chloride or polyacrylamide, to the wastewater to aggregate the tiny particles into larger flocs, which are convenient for subsequent separation.

[0016] Step 3: Separate the formed flocs from the waste liquid through a sedimentation tank or flotation device. Sedimentation uses gravity to sink the flocs, while flotation uses bubbles to bring the flocs to the water surface. Both are effective solid-liquid separation technologies, and the separation method is selected according to different needs.

[0017] Step 4: For wastewater containing organic pollutants, aerobic or anaerobic biological treatment methods are used to utilize microorganisms to degrade organic matter and convert it into harmless substances.

[0018] Step 5: Use filtration, adsorption, ion exchange, and membrane technology (such as reverse osmosis and ultrafiltration) to further remove soluble pollutants and microorganisms. Deep treatment ensures that the water quality meets higher standards and is suitable for specific reuse or discharge requirements.

[0019] Step 6: Use ultraviolet disinfection, ozone generator or chlorination equipment to disinfect the treated water to ensure the water quality is safe and free of pathogenic microorganisms.

[0020] Step 7: Monitor the entire purification process in real time to ensure that all indicators meet the emission or reuse standards, and monitor and control to discover and solve problems in the purification process.

[0021] Step 8: The generated sludge is concentrated, dehydrated and stabilized to reduce its volume and facilitate final disposal or resource utilization.

[0022] As a preferred technical solution, the recycling method of different materials in the physical recycling includes:

[0023] Metal recycling;

[0024] Step 1: For the contaminated metal parts, cleaning is required to remove stains and impurities;

[0025] Step 2: Some metal parts need to be broken into smaller sizes for subsequent processing;

[0026] Step 3: Use magnets to absorb ferromagnetic metals from the waste. During the magnetic separation process, the waste is first broken into small pieces, and then the ferromagnetic metals are separated by a magnetic separator;

[0027] Step 4: Through the eddy current separator, using the principle of electromagnetic induction, when metal debris passes through the changing magnetic field, eddy currents will be generated inside it, and the eddy currents will generate a magnetic field in the opposite direction of the original magnetic field, so that the metal debris is repelled and sorted out. This method can separate non-ferrous metals from non-metallic substances;

[0028] Step 5: Smelt the sorted metal to remove impurities and make new metal materials;

[0029] Plastic recycling;

[0030] Step 1: Use chemical agents to remove stains and labels from the plastic surface;

[0031] Step 2: Clean the plastic that still has residual chemicals after stain removal;

[0032] Step 3: Break the cleaned plastic items into small pieces or particles;

[0033] Step 4: Place the cleaned plastic fragments or particles into a furnace and heat them above the melting point to melt them;

[0034] Step 5: The molten plastic is made into new plastic products or plastic pellets through an extruder or injection molding machine;

[0035] Paper recycling;

[0036] Step 1: Collect various waste papers and classify them according to the materials of the paper, such as PET, HDPE, and PVC;

[0037] Step 2: For waste paper containing printing ink, deinking treatment is required to remove the ink;

[0038] Step 3: Tear or break the waste paper into small pieces, then soak and stir them into pulp in water;

[0039] Step 4: After screening, purification and bleaching, the pulp is sent to the papermaking machine to make new paper;

[0040] Glass recycling;

[0041] Step 1: Collect various glass wastes and sort them by color;

[0042] Step 2: Remove labels, dirt and other magazines adhered to the glass surface;

[0043] Step 3: Place the cleaned glass fragments or particles into a furnace and heat them above the melting point to melt them;

[0044] Step 4: The molten glass is made into new glass products by blowing, pressing or drawing.

[0045] As a preferred technical solution, the recycling method of different materials in the chemical recycling is:

[0046] Electronic waste recycling;

[0047] Step 1: First, soak the circuit board in an acid solution to separate the metal from the circuit board;

[0048] Step 2: Place the separated metals into an electrolytic cell for electrolysis to extract the precious metals;

[0049] Step 3: Refining the extracted precious metals to increase their purity;

[0050] Chemical recycling of organic waste;

[0051] Step 1: Under heating conditions, the combustible solid waste first undergoes a cracking process to precipitate volatile matter, tar, methane, oxygen and other gaseous products; as the temperature rises, the macromolecular substances crack again to generate complex gases and small molecules such as methane and oxygen. The secondary reaction stage can be divided into the secondary reaction of small molecules and the secondary reaction of macromolecules. The secondary reaction of small molecules refers to the decomposition of ethylene, acetylene, etc. into methane and hydrogen; the secondary pyrolysis reaction of macromolecules refers to the process in which compounds containing benzene rings, exciton compounds, and amino compounds are cracked again and decomposed into small molecules such as methane, benzene, water, and carbon;

[0052] Step 2: Unlike completely oxygen-free pyrolysis, by operating in an oxygen-deficient environment, there is insufficient oxygen during the gasification process, converting organic matter into combustible gas. The combustible gas produced during the gasification process can be used to generate electricity or as a fuel for other industrial processes.

[0053] As a preferred technical solution, the different transformation processes in the biotransformation include:

[0054] Pretreatment;

[0055] Pretreatment includes crushing, adjusting humidity and carbon-nitrogen ratio. For example, food waste needs to be crushed by a grinder to increase its surface area and promote the decomposition of microorganisms. At the same time, according to different types of organic matter, its water content needs to be adjusted to ensure suitable humidity conditions so that microorganisms can grow and metabolize. In addition, in order to optimize the growth environment of microorganisms, the carbon-nitrogen ratio needs to be adjusted to an ideal range (this value is usually between 25:1 and 30:1);

[0056] Composting;

[0057] Step 1: Pile the pre-treated organic waste in a well-ventilated place to form a compost pile. The height and width of the compost pile should be moderate to ensure that oxygen can fully penetrate into the pile.

[0058] Step 2: In order to maintain the ventilation and temperature of the pile, the compost pile needs to be turned regularly to prevent the occurrence of anaerobic conditions;

[0059] Step 3: During the composting process, the temperature will naturally rise due to the heat generated by the metabolic activity of microorganisms. Maintaining a suitable temperature range (usually 50-65°C) can accelerate the decomposition of organic matter and kill pathogens;

[0060] Step 4: The final product of composting needs to be properly processed, including screening, packaging, storage and transportation. For compost, screening can remove impurities and large pieces of matter; packaging is for easy storage and transportation; and storage requires the selection of appropriate places and conditions;

[0061] Anaerobic digestion;

[0062] Step 1: Place the organic waste into an anaerobic reactor and seal it to prevent oxygen from entering. The reactor should be designed to ensure that the organic matter can be fully mixed and fully contacted with the microorganisms;

[0063] Step 2: To start the anaerobic digestion process, an appropriate amount of inoculum needs to be added to the reactor. This inoculum usually contains a rich supply of anaerobic microorganisms, which can quickly adapt to the new environment and begin to decompose organic matter.

[0064] Step 3: By controlling the temperature and pH value in the reactor, the growth and metabolic activity of microorganisms can be promoted. The suitable temperature range is usually 35-55°C, and the pH value should be kept at neutral or slightly alkaline.

[0065] Step 4: Purify the generated biogas for use in power generation or as fuel;

[0066] Different energy recovery methods in the energy recovery include:

[0067] Incineration for power generation;

[0068] Step 1: Send the treated waste into the incinerator for combustion, producing high-temperature flue gas and solid residue;

[0069] Step 2: Use the high-temperature flue gas to generate steam, drive the steam turbine to rotate, and then drive the generator to generate electricity;

[0070] Step 3: The waste heat generated during the power generation process can be used for heating or industrial purposes;

[0071] Pyrolysis and gasification;

[0072] Step 1: Heating the waste in anoxic conditions to decompose it into combustible gas and solid residue;

[0073] Step 2: Further heating the solid residue to convert it into more combustible gas by gasification in an oxygen-deficient environment;

[0074] Step 3: The generated combustible gas is used for power generation or as a chemical raw material. It can be used for gas turbine power generation or as a raw material for synthesis gas, and further processed into chemicals or fuels.

[0075] As a preferred technical solution, the repair process of different materials in the material repair includes:

[0076] Restoration of building materials;

[0077] Step 1: Use a crusher to crush construction waste into particles of a certain size;

[0078] Step 2: Screen the crushed particles through a vibrating screen or other screening equipment to remove impurities;

[0079] Step 3: Use the screened aggregates in concrete production or other building materials for recycling;

[0080] Textile restoration;

[0081] Step 1: Wash the clothes with water or detergent to remove stains and odors;

[0082] Step 2: Check if the clothes have any damage and repair them or replace the fabric;

[0083] Step 3: Dye the garment as needed to restore its original color and appearance quality.

[0084] As a preferred technical solution, the different resource recovery processes in the special resource recovery include:

[0085] Medical waste disposal;

[0086] Step 1: Use high temperature or chemical agents to thoroughly disinfect medical waste to kill pathogenic microorganisms and other harmful substances;

[0087] Step 2: Break the disinfected waste into small pieces for subsequent processing;

[0088] Step 3: Choose a safe disposal method based on the nature of the medical waste, such as landfill or incineration;

[0089] Battery recycling;

[0090] Step 1: Use professional tools to open the battery shell and take out the internal substances;

[0091] Step 2: Using hydrometallurgical technology to extract metals, lithium carbonate, nickel sulfate, cobalt sulfate and other valuable metal compounds are extracted by ion exchange and electrodeposition;

[0092] Step 3: Use these extracted substances in the production of new batteries or other purposes.

[0093] This method has the following beneficial effects:

[0094] By integrating advanced sorting technology, physical recycling methods, chemical recycling processes and biological conversion processes, this system can efficiently separate valuable substances from urban waste and reuse them. For example, after careful sorting, cleaning, crushing and smelting, materials such as metals, plastics, paper and glass can be converted into high-quality raw materials and re-enter the production cycle. This not only significantly improves the recovery rate of resources, but also greatly improves the quality and market value of recycled materials, thereby promoting the sustainable use of resources.

[0095] The system adopts a comprehensive waste liquid treatment process, including pH adjustment, coagulant addition, sedimentation separation, filtration and deep treatment, etc., to ensure that harmful substances in the waste liquid are effectively removed; in addition, through energy recovery methods such as incineration power generation and pyrolysis gasification, it can not only convert waste into electricity or fuel, but also reduce the amount of landfill, thereby reducing the risk of soil and water pollution. At the same time, measures such as concentration, dehydration and final disposal are also taken for the treatment of sludge to ensure that it does not cause secondary pollution to the environment. These comprehensive measures work together to effectively reduce the burden of urban waste on the environment.

[0096] The implementation of this system and method will help promote the development of a circular economy model, achieve waste reduction, resource utilization and harmlessness, and reduce dependence on original resources and consumption of new resources by increasing the resource recovery rate and reuse rate of waste, which is in line with the goal of energy conservation and emission reduction. At the same time, the operation of the system can also create new economic growth points, such as the recycled materials industry and the new energy industry, providing impetus for the green transformation of the social economy. In addition, the system can also enhance the public's environmental awareness and promote all sectors of society to participate in environmental protection and sustainable development actions.

[0097] Of course, any product implementing the present method does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] In order to more clearly illustrate the technical solution of the embodiment of the present method, the drawings required for describing the embodiment will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present method. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0099] Figure 1 A flow chart of a system and method for recycling urban wastes according to the present method;

[0100] Figure 2 A method flow chart for waste liquid recycling of this method;

[0101] Figure 3 A flow chart of the method for physical recovery of the present method;

[0102] Figure 4 The process flow chart of chemical recovery of the present method is as follows;

[0103] Figure 5 The flowchart of the bioconversion method of the present invention is shown in FIG.

[0104] Figure 6 A flow chart of the method for energy recovery of the present method;

[0105] Figure 7 A flow chart of the method for material repair in this method;

[0106] Figure 8 Flow chart of the method for special resource recovery in this method. DETAILED DESCRIPTION

[0107] The following will be combined with the drawings in the embodiments of the present method to clearly and completely describe the technical solutions in the embodiments of the present method. Obviously, the described embodiments are only part of the embodiments of the present method, not all of the embodiments. Based on the embodiments of the present method, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present method.

[0108] See also Figure 1-8 As shown, the method is a system and method for recycling urban waste, including centralized waste collection, filtration, waste liquid circulation, sorting, physical recovery, chemical recovery, biological conversion, energy recovery, material repair and special resource recovery;

[0109] Centralized waste collection is connected with filtration; filtration is connected with waste liquid circulation and sorting respectively; sorting is connected with physical recycling, chemical recycling, biological conversion, energy recovery, material repair and special resource recycling respectively.

[0110] Centralized waste collection is responsible for deploying garbage bins of different categories in every corner of the city. These garbage bins make preliminary distinctions between the garbage placed therein, and the categories are classified into recyclables, hazardous waste, wet garbage and dry garbage. Special waste transport vehicles are used, and different carriages are configured according to different types of waste to avoid secondary pollution caused by mixed transportation, and the waste is placed at the waste collection point;

[0111] Filtration is responsible for filtering dry and wet wastes, and performs preliminary filtration through roughening, grilles, rotary screens or grit chambers to remove large particles of impurities and suspended matter, and separate waste from liquids;

[0112] Sorting is responsible for sorting the waste that is mixed with waste that does not belong to this category through the use of automated sorting lines in the sorting center to carefully sort the waste so that different types of waste can be effectively separated.

[0113] The recycling method of waste liquid after filtration is:

[0114] Step 1: Adjust different pH values ​​according to different usage requirements. For domestic water, including drinking water, bathing water, and daily water, the appropriate pH value range is usually between 6.5 and 8.5. The water quality within this range is safe for human health and also meets relevant health standards;

[0115] For industrial cooling water systems, the appropriate pH range is usually between 7.0 and 8.5. pH values ​​within this range prevent scale formation and reduce corrosion to metal pipes.

[0116] For boiler feed water, pH value control is more stringent and usually needs to be maintained within a specific range, such as 9.0 to 10.0, to ensure safe operation of the boiler.

[0117] Step 2: Add a coagulant, such as polyaluminium chloride or polyacrylamide, to the wastewater to aggregate the tiny particles into larger flocs, which are convenient for subsequent separation.

[0118] Step 3: Separate the formed flocs from the waste liquid through a sedimentation tank or flotation device. Sedimentation uses gravity to sink the flocs, while flotation uses bubbles to bring the flocs to the water surface. Both are effective solid-liquid separation technologies, and the separation method is selected according to different needs.

[0119] Step 4: For wastewater containing organic pollutants, aerobic or anaerobic biological treatment methods are used to utilize microorganisms to degrade organic matter and convert it into harmless substances.

[0120] Step 5: Use filtration, adsorption, ion exchange, and membrane technologies such as reverse osmosis and ultrafiltration to further remove soluble pollutants and microorganisms. Deep treatment ensures that water quality reaches higher standards and is suitable for specific reuse or discharge requirements.

[0121] Step 6: Use ultraviolet disinfection, ozone generator or chlorination equipment to disinfect the treated water to ensure the water quality is safe and free of pathogenic microorganisms.

[0122] Step 7: Monitor the entire purification process in real time to ensure that all indicators meet the emission or reuse standards, and monitor and control to discover and solve problems in the purification process.

[0123] Step 8: The generated sludge is concentrated, dehydrated and stabilized to reduce its volume and facilitate final disposal or resource utilization.

[0124] Methods for recycling different materials in physical recycling include:

[0125] 1. Metal recycling;

[0126] Step 1: For the contaminated metal parts, cleaning is required to remove stains and impurities;

[0127] Step 2: Some metal parts need to be broken into smaller sizes for subsequent processing;

[0128] Step 3: Use magnets to absorb ferromagnetic metals from the waste. During the magnetic separation process, the waste is first broken into small pieces, and then the ferromagnetic metals are separated by a magnetic separator;

[0129] Step 4: Through the eddy current separator, using the principle of electromagnetic induction, when metal debris passes through the changing magnetic field, eddy currents will be generated inside it, and the eddy currents will generate a magnetic field in the opposite direction of the original magnetic field, so that the metal debris is repelled and sorted out. This method can separate non-ferrous metals from non-metallic substances;

[0130] Step 5: Smelt the sorted metal to remove impurities and make new metal materials;

[0131] 2. Plastic recycling;

[0132] Step 1: Use chemical agents to remove stains and labels from the plastic surface;

[0133] Step 2: Clean the plastic that still has residual chemicals after stain removal;

[0134] Step 3: Break the cleaned plastic items into small pieces or particles;

[0135] Step 4: Place the cleaned plastic fragments or particles into a furnace and heat them above the melting point to melt them;

[0136] Step 5: The molten plastic is made into new plastic products or plastic pellets through an extruder or injection molding machine;

[0137] 3. Paper recycling;

[0138] Step 1: Collect various waste papers and classify them according to the materials of the paper, such as PET, HDPE, and PVC;

[0139] Step 2: For waste paper containing printing ink, deinking treatment is required to remove the ink;

[0140] Step 3: Tear or break the waste paper into small pieces, then soak and stir them into pulp in water;

[0141] Step 4: After screening, purification and bleaching, the pulp is sent to the papermaking machine to make new paper;

[0142] 4. Glass recycling;

[0143] Step 1: Collect various glass wastes and sort them by color;

[0144] Step 2: Remove labels, dirt and other magazines adhered to the glass surface;

[0145] Step 3: Place the cleaned glass fragments or particles into a furnace and heat them above the melting point to melt them;

[0146] Step 4: The molten glass is made into new glass products by blowing, pressing or drawing.

[0147] Recycling methods for different materials in chemical recycling:

[0148] 1. Electronic waste recycling;

[0149] Step 1: First, soak the circuit board in an acid solution to separate the metal from the circuit board;

[0150] Step 2: Place the separated metals into an electrolytic cell for electrolysis to extract the precious metals;

[0151] Step 3: Refining the extracted precious metals to increase their purity;

[0152] 2. Chemical recycling of organic waste;

[0153] Step 1: Under heating conditions, the combustible solid waste first undergoes a cracking process to precipitate volatile matter, tar, methane, oxygen and other gaseous products; as the temperature rises, the macromolecular substances crack again to generate complex gases and small molecules such as methane and oxygen. The secondary reaction stage can be divided into the secondary reaction of small molecules and the secondary reaction of macromolecules. The secondary reaction of small molecules refers to the decomposition of ethylene, acetylene, etc. into methane and hydrogen; the secondary pyrolysis reaction of macromolecules refers to the process in which compounds containing benzene rings, exciton compounds, and amino compounds are cracked again and decomposed into small molecules such as methane, benzene, water, and carbon;

[0154] Step 2: Unlike completely oxygen-free pyrolysis, by operating in an oxygen-deficient environment, there is insufficient oxygen during the gasification process, converting organic matter into combustible gas. The combustible gas produced during the gasification process can be used to generate electricity or as a fuel for other industrial processes.

[0155] The different transformation processes involved in biotransformation include:

[0156] 1. Pretreatment;

[0157] Pretreatment includes crushing, adjusting humidity and carbon-nitrogen ratio. For example, food waste needs to be crushed by a grinder to increase its surface area and promote the decomposition of microorganisms. At the same time, according to different types of organic matter, its water content needs to be adjusted to ensure suitable humidity conditions so that microorganisms can grow and metabolize. In addition, in order to optimize the growth environment of microorganisms, the carbon-nitrogen ratio needs to be adjusted to an ideal range. This value is usually between 25:1 and 30:1.

[0158] 2. Composting;

[0159] Step 1: Pile the pre-treated organic waste in a well-ventilated place to form a compost pile. The height and width of the compost pile should be moderate to ensure that oxygen can fully penetrate into the pile.

[0160] Step 2: In order to maintain the ventilation and temperature of the pile, the compost pile needs to be turned regularly to prevent the occurrence of anaerobic conditions;

[0161] Step 3: During the composting process, the temperature will naturally rise due to the heat generated by the metabolic activities of microorganisms. Maintaining a suitable temperature range, usually 50-65°C, can accelerate the decomposition of organic matter and kill pathogens;

[0162] Step 4: The final product of composting needs to be properly processed, including screening, packaging, storage and transportation. For compost, screening can remove impurities and large pieces of matter; packaging is for easy storage and transportation; and storage requires the selection of appropriate places and conditions;

[0163] 3. Anaerobic digestion;

[0164] Step 1: Place the organic waste into an anaerobic reactor and seal it to prevent oxygen from entering. The reactor should be designed to ensure that the organic matter can be fully mixed and fully contacted with the microorganisms;

[0165] Step 2: To start the anaerobic digestion process, an appropriate amount of inoculum needs to be added to the reactor. This inoculum usually contains a rich supply of anaerobic microorganisms, which can quickly adapt to the new environment and begin to decompose organic matter.

[0166] Step 3: By controlling the temperature and pH value in the reactor, the growth and metabolic activity of microorganisms can be promoted. The suitable temperature range is usually 35-55°C, and the pH value should be kept at neutral or slightly alkaline.

[0167] Step 4: Purify the generated biogas for use in power generation or as fuel;

[0168] The different energy recovery methods in energy recovery include;

[0169] 1. Incineration for power generation;

[0170] Step 1: Send the treated waste into the incinerator for combustion, producing high-temperature flue gas and solid residue;

[0171] Step 2: Use the high-temperature flue gas to generate steam, drive the steam turbine to rotate, and then drive the generator to generate electricity;

[0172] Step 3: The waste heat generated during the power generation process can be used for heating or industrial purposes;

[0173] 2. Pyrolysis and gasification;

[0174] Step 1: Heating the waste in anoxic conditions to decompose it into combustible gas and solid residue;

[0175] Step 2: Further heating the solid residue to convert it into more combustible gas by gasification in an oxygen-deficient environment;

[0176] Step 3: The generated combustible gas is used for power generation or as a chemical raw material. It can be used for gas turbine power generation or as a raw material for synthesis gas, and further processed into chemicals or fuels.

[0177] The repair process of different materials in material repair includes:

[0178] 1. Repair of building materials;

[0179] Step 1: Use a crusher to crush construction waste into particles of a certain size;

[0180] Step 2: Screen the crushed particles through a vibrating screen or other screening equipment to remove impurities;

[0181] Step 3: Use the screened aggregates in concrete production or other building materials for recycling;

[0182] 2. Textile repair;

[0183] Step 1: Wash the clothes with water or detergent to remove stains and odors;

[0184] Step 2: Check if the clothes have any damage and repair them or replace the fabric;

[0185] Step 3: Dye the garment as needed to restore its original color and appearance quality.

[0186] The different resource recovery processes in special resource recovery include:

[0187] 1. Medical waste treatment;

[0188] Step 1: Use high temperature or chemical agents to thoroughly disinfect medical waste to kill pathogenic microorganisms and other harmful substances;

[0189] Step 2: Break the disinfected waste into small pieces for subsequent processing;

[0190] Step 3: Choose a safe disposal method based on the nature of the medical waste, such as landfill or incineration;

[0191] 2. Battery recycling;

[0192] Step 1: Use professional tools to open the battery shell and take out the internal substances;

[0193] Step 2: Using hydrometallurgical technology to extract metals, lithium carbonate, nickel sulfate, cobalt sulfate and other valuable metal compounds are extracted by ion exchange and electrodeposition;

[0194] Step 3: Use these extracted substances in the production of new batteries or other purposes.

[0195] It is worth noting that in the above system embodiment, the various units included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the protection scope of this method.

[0196] In addition, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiments can be completed by instructing related hardware through a program, and the corresponding program can be stored in a computer-readable storage medium.

[0197] The preferred embodiments of the method disclosed above are only used to help explain the method. The preferred embodiments do not describe all the details in detail, nor do they limit the method to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the method, so that those skilled in the art can understand and use the method well. The method is limited only by the claims and their full scope and equivalents.

Claims

1. A system and method for recycling urban waste, including centralized waste collection, filtration, waste liquid circulation, sorting, physical recovery, chemical recovery, biological conversion, energy recovery, material repair and special resource recovery; characterized by: The centralized waste collection is connected with filtration; the filtration is respectively connected with waste liquid circulation and sorting; the sorting is respectively connected with physical recycling, chemical recycling, biological conversion, energy recycling, material repair and special resource recycling.

2. A system and method for recycling urban waste according to claim 1, characterized in that: The centralized waste collection is responsible for deploying garbage bins of different classifications in every corner of the city. These garbage bins make preliminary distinctions between the garbage placed therein, and the categories are classified into recyclables, hazardous waste, wet garbage and dry garbage. Special waste transport vehicles are used, and different carriages are configured according to different types of waste to avoid secondary pollution caused by mixed transportation, and the garbage is placed at the waste collection point; The filtration is responsible for filtering dry and wet wastes, and performs preliminary filtration through roughening, grilles, rotary screens or grit chamber equipment to remove large particles of impurities and suspended matter, and separate wastes from liquids; The sorting is responsible for carefully classifying the waste mixed in the waste that does not belong to this category by using an automated sorting line in the sorting center, so that the various types of waste can be effectively separated.

3. A system and method for recycling urban waste according to claim 1, characterized in that: The circulation method of the waste liquid after filtration is: Step 1: Adjust different pH values ​​according to different usage requirements. For domestic water, including drinking water, bathing water, and daily water, the appropriate pH value range is usually between 6.5 and 8.

5. The water quality within this range is safe for human health and also meets relevant health standards; For industrial cooling water systems, the appropriate pH range is usually between 7.0 and 8.

5. pH values ​​within this range prevent scale formation and reduce corrosion to metal pipes. For boiler feed water, pH value control is more stringent and usually needs to be maintained within a specific range, such as 9.0 to 10.0, to ensure safe operation of the boiler. Step 2: Add a coagulant, such as polyaluminium chloride or polyacrylamide, to the wastewater to aggregate the tiny particles into larger flocs, which are convenient for subsequent separation. Step 3: Separate the formed flocs from the waste liquid through a sedimentation tank or flotation device. Sedimentation uses gravity to sink the flocs, while flotation uses bubbles to bring the flocs to the water surface. Both are effective solid-liquid separation technologies, and the separation method is selected according to different needs. Step 4: For wastewater containing organic pollutants, aerobic or anaerobic biological treatment methods are used to utilize microorganisms to degrade organic matter and convert it into harmless substances. Step 5: Use filtration, adsorption, ion exchange, and membrane technology (such as reverse osmosis and ultrafiltration) to further remove soluble pollutants and microorganisms. Deep treatment ensures that the water quality meets higher standards and is suitable for specific reuse or discharge requirements. Step 6: Use ultraviolet disinfection, ozone generator or chlorination equipment to disinfect the treated water to ensure the water quality is safe and free of pathogenic microorganisms. Step 7: Monitor the entire purification process in real time to ensure that all indicators meet the emission or reuse standards, and monitor and control to discover and solve problems in the purification process. Step 8: The generated sludge is concentrated, dehydrated and stabilized to reduce its volume and facilitate final disposal or resource utilization.

4. A system and method for recycling urban waste according to claim 1, characterized in that: The recycling methods of different materials in the physical recycling include: (1) Metal recovery; Step 1: For the contaminated metal parts, cleaning is required to remove stains and impurities; Step 2: Some metal parts need to be broken into smaller sizes for subsequent processing; Step 3: Use magnets to absorb ferromagnetic metals from the waste. During the magnetic separation process, the waste is first broken into small pieces, and then the ferromagnetic metals are separated by a magnetic separator; Step 4: Through the eddy current separator, using the principle of electromagnetic induction, when metal debris passes through the changing magnetic field, eddy currents will be generated inside it, and the eddy currents will generate a magnetic field in the opposite direction of the original magnetic field, so that the metal debris is repelled and sorted out. This method can separate non-ferrous metals from non-metallic substances; Step 5: Smelt the sorted metal to remove impurities and make new metal materials; (2) Plastic recycling; Step 1: Use chemical agents to remove stains and labels from the plastic surface; Step 2: Clean the plastic that still has residual chemicals after stain removal; Step 3: Break the cleaned plastic items into small pieces or particles; Step 4: Place the cleaned plastic fragments or particles into a furnace and heat them above the melting point to melt them; Step 5: The molten plastic is made into new plastic products or plastic pellets through an extruder or injection molding machine; (3) Paper recycling; Step 1: Collect various waste papers and classify them according to the materials of the paper, such as PET, HDPE, and PVC; Step 2: For waste paper containing printing ink, deinking treatment is required to remove the ink; Step 3: Tear or break the waste paper into small pieces, then soak and stir them into pulp in water; Step 4: After screening, purification and bleaching, the pulp is sent to the papermaking machine to make new paper; (4) Glass recycling; Step 1: Collect various glass wastes and sort them by color; Step 2: Remove labels, dirt and other magazines adhered to the glass surface; Step 3: Place the cleaned glass fragments or particles into a furnace and heat them above the melting point to melt them; Step 4: The molten glass is made into new glass products by blowing, pressing or drawing.

5. The system and method for recycling urban waste according to claim 1, characterized in that: Recycling methods of different materials in the chemical recycling: (1) Electronic waste recycling; Step 1: First, soak the circuit board in an acid solution to separate the metal from the circuit board; Step 2: Place the separated metals into an electrolytic cell for electrolysis to extract the precious metals; Step 3: Refining the extracted precious metals to increase their purity; (2) Chemical recycling of organic waste; Step 1: Under heating conditions, the combustible solid waste first undergoes a cracking process to precipitate volatile matter, tar, methane, oxygen and other gaseous products; as the temperature rises, the macromolecular substances crack again to generate complex gases and small molecules such as methane and oxygen. The secondary reaction stage can be divided into the secondary reaction of small molecules and the secondary reaction of macromolecules. The secondary reaction of small molecules refers to the decomposition of ethylene, acetylene, etc. into methane and hydrogen; the secondary pyrolysis reaction of macromolecules refers to the process in which compounds containing benzene rings, exciton compounds, and amino compounds are cracked again and decomposed into small molecules such as methane, benzene, water, and carbon; Step 2: Unlike completely oxygen-free pyrolysis, by operating in an oxygen-deficient environment, there is insufficient oxygen during the gasification process, converting organic matter into combustible gas. The combustible gas produced during the gasification process can be used to generate electricity or as a fuel for other industrial processes.

6. The system and method for recycling urban waste according to claim 1, characterized in that: The different transformation processes in the biotransformation include: (1) Pretreatment; Pretreatment includes crushing, adjusting humidity and carbon-nitrogen ratio. For example, food waste needs to be crushed by a grinder to increase its surface area and promote the decomposition of microorganisms. At the same time, according to different types of organic matter, its water content needs to be adjusted to ensure suitable humidity conditions so that microorganisms can grow and metabolize. In addition, in order to optimize the growth environment of microorganisms, the carbon-nitrogen ratio needs to be adjusted to an ideal range (this value is usually between 25:1 and 30:1); (2) Composting; Step 1: Pile the pre-treated organic waste in a well-ventilated place to form a compost pile. The height and width of the compost pile should be moderate to ensure that oxygen can fully penetrate into the pile. Step 2: In order to maintain the ventilation and temperature of the pile, the compost pile needs to be turned regularly to prevent the occurrence of anaerobic conditions; Step 3: During the composting process, the temperature will naturally rise due to the heat generated by the metabolic activity of microorganisms. Maintaining a suitable temperature range (usually 50-65°C) can accelerate the decomposition of organic matter and kill pathogens; Step 4: The final product of composting needs to be properly processed, including screening, packaging, storage and transportation. For compost, screening can remove impurities and large pieces of matter; packaging is for easy storage and transportation; and storage requires the selection of appropriate places and conditions; (3) Anaerobic digestion; Step 1: Place the organic waste into an anaerobic reactor and seal it to prevent oxygen from entering. The reactor should be designed to ensure that the organic matter can be fully mixed and fully contacted with the microorganisms; Step 2: To start the anaerobic digestion process, an appropriate amount of inoculum needs to be added to the reactor. This inoculum usually contains a rich supply of anaerobic microorganisms, which can quickly adapt to the new environment and begin to decompose organic matter. Step 3: By controlling the temperature and pH value in the reactor, the growth and metabolic activity of microorganisms can be promoted. The suitable temperature range is usually 35-55°C, and the pH value should be kept at neutral or slightly alkaline. Step 4: Purify the generated biogas for use in power generation or as fuel; Different energy recovery methods in the energy recovery include: (1) Incineration for power generation; Step 1: Send the treated waste into the incinerator for combustion, producing high-temperature flue gas and solid residue; Step 2: Use the high-temperature flue gas to generate steam, drive the steam turbine to rotate, and then drive the generator to generate electricity; Step 3: The waste heat generated during the power generation process can be used for heating or industrial purposes; (2) Pyrolysis and gasification; Step 1: Heating the waste in anoxic conditions to decompose it into combustible gas and solid residue; Step 2: Further heating the solid residue to convert it into more combustible gas by gasification in an oxygen-deficient environment; Step 3: The generated combustible gas is used for power generation or as a chemical raw material. It can be used for gas turbine power generation or as a raw material for synthesis gas, and further processed into chemicals or fuels.

7. The system and method for recycling urban waste according to claim 1, characterized in that: The repair process of different materials in the material repair includes: (1) Repair of building materials; Step 1: Use a crusher to crush construction waste into particles of a certain size; Step 2: Screen the crushed particles through a vibrating screen or other screening equipment to remove impurities; Step 3: Use the screened aggregates in concrete production or other building materials for recycling; (2) Textile repair; Step 1: Wash the clothes with water or detergent to remove stains and odors; Step 2: Check if the clothes have any damage and repair them or replace the fabric; Step 3: Dye the garment as needed to restore its original color and appearance quality.

8. The system and method for recycling urban waste according to claim 1, characterized in that: The different resource recovery processes in the special resource recovery include: (1) Medical waste treatment; Step 1: Use high temperature or chemical agents to thoroughly disinfect medical waste to kill pathogenic microorganisms and other harmful substances; Step 2: Break the disinfected waste into small pieces for subsequent processing; Step 3: Choose a safe disposal method based on the nature of the medical waste, such as landfilling or incineration; (2) Battery recycling; Step 1: Use professional tools to open the battery shell and take out the internal substances; Step 2: Using hydrometallurgical technology to extract metals, lithium carbonate, nickel sulfate, cobalt sulfate and other valuable metal compounds are extracted by ion exchange and electrodeposition; Step 3: Use these extracted substances in the production of new batteries or other purposes.

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