Modularized high-concentration excrement collection sewage treatment system and resource recovery method

Abstract

The invention discloses a modularized high-concentration excrement collection sewage treatment system and a resource recovery method. High-concentration excrement collection sewage mainly comes from places where excrement collection facilities are intensively used, such as railway trains, ships and large-scale activity places. Comprising a physicochemical pretreatment unit, a composite biodegradation unit, an electrochemical advanced treatment unit and a resource circulation unit, the physicochemical pretreatment unit is used for removing suspended solids in the sewage and destroying an organic matter structure in the sewage; the composite biodegradation unit comprises an ABR (anaerobic baffled reactor) anaerobic section and an MBBR (moving bed biofilm reactor) aerobic section; the electrochemical deep treatment unit comprises an electro-Fenton reaction tank, an ultraviolet disinfection module and an intelligent control module; and the resource circulation unit comprises a sludge treatment unit and a resource recovery unit. The problems of incomplete pretreatment, low nitrogen and phosphorus removal efficiency and serious resource waste in the prior art are solved.

Description

Technical Field

[0002] This invention belongs to the field of wastewater treatment technology, specifically relating to a modular high-concentration sewage treatment system and resource recovery method. Background Technology

[0003] High-concentration sewage mainly originates from places where sewage collection facilities are used intensively, such as railway trains, ships, and large event venues. This sewage has the following significant characteristics: 1) High pollutant concentration: The chemical oxygen demand (COD) and biochemical oxygen demand (BOD) values ​​of sewage are extremely high, usually much higher than those of ordinary domestic sewage, and it contains a large amount of organic matter, nitrogen, phosphorus and other pollutants; 2) Complex composition: In addition to common organic pollutants, it may also contain pathogens, heavy metals, and recalcitrant organic matter, making it difficult to treat; 3) Intermittent discharge: The discharge of sewage is usually intermittent, with large fluctuations in flow and water quality, which places high demands on the sewage treatment system's ability to withstand shock loads.

[0004] In response to the aforementioned characteristics of high-concentration sewage, its treatment requirements mainly include: Highly efficient pollutant removal: Effective removal of organic matter, nitrogen, phosphorus, and other pollutants from the sewage is necessary to ensure that the treated water meets relevant discharge standards. Resource recovery and utilization: Simultaneously treating sewage, resource recovery and utilization should be maximized, such as phosphorus recovery and energy recovery, to improve the economic efficiency and sustainability of sewage treatment. Environmental friendliness: Secondary pollution should be minimized during the treatment process, and the generation of harmful disinfection byproducts should be avoided.

[0005] Currently, the main technologies for treating high-concentration sewage are as follows: Physical treatment methods mainly include screens, sedimentation, and filtration, primarily used to remove suspended solids and large particulate impurities from wastewater. While these methods are simple to operate, they are less effective at removing dissolved organic matter and nutrients from wastewater, making them unsuitable for treating high-concentration sewage.

[0006] Chemical treatment methods, such as chemical precipitation and oxidation-reduction, remove heavy metal ions and recalcitrant organic matter from wastewater through the action of chemical agents. However, chemical treatment methods suffer from problems such as high agent costs, secondary pollution, and limited effectiveness in removing organic matter from wastewater.

[0007] Biological treatment methods, such as activated sludge and biofilm processes, utilize the metabolic activity of microorganisms to decompose organic matter in wastewater. Biological treatment methods offer advantages such as high treatment efficiency and low operating costs, but their efficiency in treating high-concentration sewage needs further improvement. For example, the traditional A²O process achieves a nitrogen removal rate of only 60-75% when treating high-concentration sewage, which is insufficient to achieve the desired treatment effect.

[0008] To overcome the shortcomings of single treatment methods, several combined treatment processes have been developed in recent years. For example, the MBBR (Moving Bed Biofilm Reactor) + magnetic coagulation process has been applied to the treatment of sewage from railway trains. The MBBR process combines the high efficiency and operational flexibility of the activated sludge process with the traditional biofilm process's resistance to shock loads, long sludge age, and low residual sludge content, thus enhancing the treatment effect of the biological system. The magnetic coagulation process has high sedimentation efficiency, a small footprint, and can effectively remove suspended solids and some organic matter from sewage. However, these combined processes still have some problems when treating high-concentration sewage, such as the need for further improvement in treatment efficiency and insufficient resource recovery capacity. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, this invention provides a modular high-concentration sewage treatment system and resource recovery method, which solves the problems of incomplete pretreatment, low nitrogen and phosphorus removal efficiency, and serious resource waste in existing technologies.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A modular high-concentration sewage treatment system includes a physicochemical pretreatment unit, a composite biodegradation unit, an electrochemical deep treatment unit, and a resource recycling unit. The physicochemical pretreatment unit is used to remove suspended solids from wastewater and break down the structure of organic matter in wastewater. The composite biodegradation unit includes an anaerobic ABR section and an aerobic MBBR section; The electrochemical deep treatment unit includes an electro-Fenton reaction cell, an ultraviolet disinfection module, and an intelligent control module. The resource recycling unit includes a sludge treatment unit and a resource recovery unit.

[0011] Furthermore, the physicochemical pretreatment unit includes a screw extrusion dewatering machine, which is connected to an ultrasonic cavitation reactor.

[0012] Furthermore, polyethylene suspension packing is added to the aerobic section of the MBBR.

[0013] Furthermore, the ultraviolet disinfection module uses a low-pressure, high-intensity mercury lamp.

[0014] Furthermore, the sludge treatment unit includes a mesophilic anaerobic digester, a screw press dewatering machine, and a biogas purification device.

[0015] Furthermore, the resource recovery unit includes a crystallization reactor, a membrane distillation unit, and a waste heat exchanger.

[0016] A resource recycling method includes the following steps: Step S1: Pretreatment: spiral extrusion dehydration and ultrasonic cavitation treatment; Step S2: Combined biological reaction: anaerobic treatment and aerobic treatment; Step S3: Deep processing: electro-Fenton reaction, ultraviolet disinfection, and intelligent control module integrates IoT terminal, PLC controller and cloud server to build a data acquisition and control system; Step S4: Sludge treatment and resource recycling.

[0017] Furthermore, the biogas purification device uses a bio-trickling filter for desulfurization.

[0018] Furthermore, the waste heat exchanger is used to recover the waste heat generated in the exhaust gas during the wastewater treatment process.

[0019] Furthermore, membrane distillation units can be used to recover useful substances from wastewater or to perform deep dewatering treatment.

[0020] The beneficial effects of this invention are: 1) This invention achieves a significant breakthrough in treatment efficiency through the synergistic effect of physicochemical pretreatment, composite biodegradation, and electrochemical deep treatment; the total COD removal rate reaches ≥98%, effectively removing organic matter from wastewater and ensuring that the treated water quality meets discharge standards; the aerobic stage of the MBBR in the composite biological reactor unit achieves an ammonia nitrogen removal rate of ≥95% through simultaneous nitrification and denitrification, solving the problem of low ammonia nitrogen removal efficiency in traditional processes; with the help of phosphorus recovery technology, the TP content can be reduced to ≤0.5mg / L, reducing phosphorus eutrophication pollution of water bodies; the electro-Fenton reactor and ultraviolet disinfection module in the deep treatment unit can efficiently inactivate pathogens in wastewater, making fecal coliforms undetectable and ensuring that the treated water quality meets disinfection requirements; at the same time, by optimizing the wastewater treatment process, the hydraulic retention time is shortened by 40% compared with traditional processes, improving system treatment efficiency; the intelligent control module monitors and regulates system operating parameters in real time, enabling the system to withstand shock loads by ±30%, enhancing the stability of system operation.

[0021] 2) This invention achieves effective phosphorus recovery (≥85%) by controlling crystallization reaction conditions, reducing phosphorus eutrophication pollution of water bodies. The recovered phosphorus is produced in the form of struvite, with an annual production of 1.5-2.0 tons of struvite fertilizer per thousand tons of wastewater, which can be directly used as a slow-release fertilizer. The organic matter in the sludge is anaerobically digested to produce biogas, which is then desulfurized and used for power generation. The biogas power generation self-sufficiency rate is ≥65%, achieving energy recovery and utilization. In addition, by recovering waste heat from the exhaust gas and optimizing system operating parameters, the energy consumption per ton of water treated is ≤1.2 kWh, further reducing system energy consumption and demonstrating good economic and environmental benefits. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the operation of the present invention. Detailed Implementation

[0023] The present invention will now be described in detail with reference to specific embodiments.

[0024] The modular high-concentration sewage treatment system of the present invention includes a physicochemical pretreatment unit, a composite biodegradation unit, an electrochemical deep treatment unit, and a resource recycling unit; the physicochemical pretreatment unit is used to remove suspended solids and destroy the structure of organic matter in sewage; the composite biodegradation unit includes an ABR anaerobic section and an MBBR aerobic section; the electrochemical deep treatment unit includes an electro-Fenton reactor, an ultraviolet disinfection module, and an intelligent control module; the resource recycling unit includes a sludge treatment unit and a resource recovery unit.

[0025] The physicochemical pretreatment unit includes a screw extruder dewatering machine connected to an ultrasonic cavitation reactor. The screw extruder dewatering machine achieves a dewatering rate of ≥65%, while the ultrasonic cavitation reactor operates at a frequency of 20-40kHz, achieving efficient solid-liquid separation and breakdown of extracellular polymeric substances (EPS), increasing the SCOD / TCOD ratio to 0.45-0.60. The screw extruder dewatering machine is equipped with a 0.3-1.0mm sieve, effectively removing suspended solids from wastewater. The ultrasonic cavitation reactor utilizes the cavitation effect generated by high-frequency ultrasound to disrupt the organic structure of wastewater, improving its biodegradability.

[0026] The anaerobic section of the ABR (Anaerobic Bioreactor) is divided into 3-5 compartments, filled with polyurethane elastic packing (specific surface area ≥600m² / m³). Utilizing the synergistic effect of acid-producing and methanogenic bacteria, the COD removal rate is ≥70%. The anaerobic baffled reactor, by dividing into multiple compartments, extends the residence time of wastewater within the reactor, improving the anaerobic treatment efficiency. In the aerobic section of the MBBR (Massively Modified Bioreactor), the filling rate of polyethylene suspended packing is 30-50%. Simultaneous nitrification and denitrification are achieved through microporous aeration (oxygen utilization rate ≥35%), with an ammonia nitrogen removal rate ≥90%. The moving bed biofilm reactor combines the advantages of biofilm and activated sludge processes, effectively removing ammonia nitrogen from wastewater.

[0027] The ultraviolet (UV) disinfection module uses a low-pressure, high-intensity mercury lamp. The iron-carbon micro-electrolysis packing material (Fe / C mass ratio 2:1-4:1) in the electro-Fenton reactor is linked with the H2O2 dosing system to generate hydroxyl radicals (·OH) that degrade recalcitrant organic matter. The electro-Fenton reactor effectively removes recalcitrant organic matter from wastewater through electrochemical oxidation. The low-pressure, high-intensity mercury lamp has a wavelength of 254nm and a dosage of 40-80mJ / cm², forming a synergistic disinfection effect with electrochemical oxidation. The UV disinfection module effectively inactivates pathogens in wastewater, ensuring that the treated water meets disinfection requirements. The intelligent control module, based on an LSTM neural network algorithm, optimizes over 20 operating parameters in real time, including aeration rate and reagent dosing, reducing energy consumption by 15-25%. By monitoring and regulating the operating parameters of the wastewater treatment system in real time, the intelligent control module improves the system's stability and operating efficiency.

[0028] The sludge treatment unit includes a mesophilic anaerobic digester, a screw press dewatering machine, and a biogas purification device. The mesophilic anaerobic digester is one of the core pieces of equipment in sludge treatment, with its digestion temperature strictly controlled at 35±2℃. Within this temperature range, anaerobic microorganisms have the highest activity, efficiently decomposing organic matter in the sludge to produce biogas. The residence time of sludge in the mesophilic anaerobic digester is set at 15-25 days to ensure sufficient degradation of organic matter. Precise temperature control and reasonable residence time settings improve biogas yield and quality while reducing sludge volume and the content of harmful substances. The screw press dewatering machine is used to dewater the anaerobic digested sludge. After entering the dewatering machine, the water in the sludge is gradually separated through the filter screen by the screw shaft, achieving sludge volume reduction. The screw press dewatering machine has advantages such as compact structure, simple operation, and high dewatering efficiency, effectively reducing the moisture content of the sludge and facilitating subsequent transportation and disposal. The biogas purification device uses a bio-trickling filter for desulfurization treatment. Biogas produced by anaerobic digestion contains a certain amount of harmful gases such as hydrogen sulfide. Without desulfurization treatment, it can corrode subsequent biogas utilization equipment and affect the combustion efficiency of the biogas. Biotrickling filters are filled with specific biological packing materials. As hydrogen sulfide and other gases pass through the packing layer, they are oxidized and decomposed by microorganisms attached to the surface of the packing material, thus purifying the biogas. Biogas treated with desulfurization has higher purity and can be used in energy recovery and utilization processes such as power generation.

[0029] The resource recovery unit includes a crystallization reactor, a membrane distillation unit, and a waste heat exchanger. The phosphate crystallizer is the key equipment for phosphorus recovery. During crystallization, reaction conditions are strictly controlled, maintaining the pH value within the range of 8.5-9.8, while adjusting the Ca / P (calcium-phosphorus) molar ratio between 1.2:1 and 1.8:1. By precisely controlling these parameters, the phosphate in the wastewater can react chemically with calcium ions to produce high-purity struvite (MgNH4PO4·6H2O). Struvite is a high-quality slow-release fertilizer that can be directly applied to agricultural production, achieving effective recovery and reuse of phosphorus resources. The membrane distillation unit uses a hydrophobic PTFE (polytetrafluoroethylene) membrane with a pore size of 0.1-0.45 μm. During operation, the liquid to be treated is heated to 40-60℃, creating a vapor pressure difference on one side of the membrane. This allows water vapor to diffuse through the membrane pores from the high-pressure side to the low-pressure side, thereby achieving liquid concentration and separation. The transmembrane pressure differential is controlled within 10-30 kPa to ensure the stability and efficiency of the membrane distillation process. Membrane distillation units offer advantages such as high separation efficiency, low energy consumption, and simple operation, and can be used to recover useful substances from wastewater or for deep dehydration treatment. Waste heat exchangers are used to recover waste heat from the exhaust gas generated during wastewater treatment. In processes such as anaerobic digestion, the equipment generates a large amount of high-temperature exhaust gas, which would be a waste of energy if directly discharged. Waste heat exchangers transfer heat from the exhaust gas to circulating water and other media through heat exchange, raising the temperature of the circulating water. The heated circulating water can then be used to maintain the temperature of the anaerobic digester, reducing the energy consumption of heating equipment and achieving cascaded energy utilization and energy conservation and emission reduction.

[0030] like Figure 1 As shown, the resource recycling method of the present invention includes the following steps: Step S1: Pretreatment: screw extrusion dehydration and ultrasonic cavitation treatment Screw extrusion dewatering: Wastewater first passes through a screw extrusion dewatering machine, where it undergoes solid-liquid separation through a screen with a 0.3-1.0mm aperture, achieving a dewatering rate of ≥65%. The screw shaft adopts a double-helix structure with a pitch of 40-60mm and a rotation speed of 1-8rpm. The screen surface is coated with a polytetrafluoroethylene anti-stick coating to effectively prevent sludge adhesion.

[0031] Ultrasonic cavitation treatment: The dehydrated wastewater enters an ultrasonic cavitation reactor, operating at a frequency of 20-40 kHz and a power density of 0.3-0.8 W / mL. The microjets generated by ultrasonic cavitation impact the solid surface, increasing the release of bound water by 15-25% and raising the SCOD / TCOD ratio to 0.45-0.60. The reactor is equipped with a titanium alloy amplitude transformer, and the reaction temperature is controlled at 25-40℃, with a cavitation time of 10-30 minutes.

[0032] Step S2: Combined biological reaction: anaerobic treatment and aerobic treatment Anaerobic treatment: Pretreated wastewater enters an anaerobic baffled reactor (ABR), divided into 3-5 series-connected compartments, each with a sludge return hole at the bottom. It is filled with polyurethane-based biological packing material with a specific surface area ≥600 m² / m³. In the anaerobic section, acid-producing bacteria and methanogens work synergistically, with a hydrolysis and acidification time of 12-24 hours, achieving a COD removal rate ≥70%.

[0033] Aerobic treatment: The anaerobic wastewater enters a moving bed biofilm reactor (MBBR) with porous polyethylene suspended packing material added. The packing material has a density of 0.93-0.98 g / cm³ and a filling rate of 30-50%. Aeration is carried out through a microporous aeration system (pore size ≤150μm), achieving an oxygen utilization rate ≥35% and realizing simultaneous nitrification and denitrification. The ammonia nitrogen removal rate is ≥90%.

[0034] Step S3: Deep processing: electro-Fenton reaction, ultraviolet disinfection, and intelligent control module integrates IoT terminal, PLC controller and cloud server to build an efficient data acquisition and control system; Electro-Fenton Reaction: Aerobic wastewater enters the electro-Fenton reactor, which contains an iron-carbon micro-electrolysis packing layer. This packing layer is composed of cast iron filings and activated carbon mixed in a mass ratio of 2:1-4:1, with a particle size of 2-8mm, and fills 60-80% of the effective height of the reactor. The H2O2 dosing system uses a metering pump linked to an ORP sensor to control the H2O2 dosage at 0.3-2.0 mmol / L, with an ORP setpoint of 400-500 mV, generating a hydroxyl radical (·OH) concentration ≥1×10⁻⁻⁻⁻⁻⁶. 4 mol / L, degrades difficult-to-treat organic matter.

[0035] Ultraviolet disinfection: Wastewater after the electro-Fenton reaction enters the ultraviolet disinfection module, which uses a low-pressure high-intensity mercury lamp with a wavelength of 254nm and a dose of 40-80mJ / cm². This forms a synergistic disinfection with electrochemical oxidation, ensuring that the pathogen inactivation rate is ≥99.99%.

[0036] Finally, the intelligent control module integrates IoT terminals, PLC controllers, and cloud servers to build a highly efficient data acquisition and control system. The IoT terminals are responsible for collecting key data from the wastewater treatment process in real time, including but not limited to parameters such as COD (Chemical Oxygen Demand), ammonia nitrogen, DO (Dissolved Oxygen), and ORP (Oxidation-Reduction Potential), and transmitting this data to the cloud server. The cloud server, acting as a data processing center, receives and stores data from the IoT terminals and deploys an LSTM neural network algorithm. The algorithm's training dataset covers more than 20 dimensions of feature parameters, including influent water quality (such as COD concentration and ammonia nitrogen concentration), ambient temperature, and equipment operating status (such as pump speed and valve opening). Through deep learning on a large amount of historical data, the LSTM neural network can build an accurate predictive model, predicting system operating trends based on real-time data acquisition and sending timely instructions to the PLC controller. The PLC controller, acting as the actuator, adjusts system operating parameters in real time according to instructions from the cloud server, such as aeration rate and reagent dosage, ensuring the system is always in optimal operating condition and achieving intelligent and precise wastewater treatment process control.

[0037] Step S4: Sludge treatment and resource recycling.

[0038] 1) Sludge treatment 1) Mesophilic anaerobic digester Mesophilic anaerobic digesters are one of the core pieces of equipment in sludge treatment, with their digestion temperature strictly controlled at 35±2℃. Within this temperature range, anaerobic microorganisms exhibit the highest activity, efficiently decomposing organic matter in the sludge to produce biogas. The residence time of sludge in the mesophilic anaerobic digester is set at 15-25 days to ensure complete degradation of organic matter. Through precise temperature control and reasonable residence time settings, the yield and quality of biogas are improved, while simultaneously reducing the volume and content of harmful substances in the sludge.

[0039] (ii) Screw press dewatering machine Screw press dewatering machines are used to dewater sludge that has undergone anaerobic digestion. After the sludge enters the dewatering machine, the water in the sludge is gradually separated out through the filter screen by the screw shaft, thus reducing the volume of the sludge. Screw press dewatering machines have advantages such as compact structure, simple operation, and high dewatering efficiency, effectively reducing the moisture content of sludge and facilitating subsequent transportation and disposal.

[0040] (iii) Biogas purification device The biogas purification system uses a bio-trickling filter for desulfurization. Biogas produced from anaerobic digestion contains a certain amount of harmful gases such as hydrogen sulfide. Without desulfurization, these gases can corrode subsequent biogas utilization equipment and affect combustion efficiency. The bio-trickling filter is filled with specific biological packing material. As hydrogen sulfide and other gases pass through the packing layer, they are oxidized and decomposed by microorganisms attached to the packing surface, thus purifying the biogas. The desulfurized biogas has higher purity and can be used in energy recovery processes such as power generation.

[0041] 2) Resource recycling 1) Phosphate crystallizer Phosphate crystallizers are key equipment for phosphorus recovery. During the crystallization process, reaction conditions are strictly controlled, maintaining the pH value within the range of 8.5-9.8, while adjusting the Ca / P (calcium-phosphorus) molar ratio between 1.2:1 and 1.8:1. By precisely controlling these parameters, the phosphate in wastewater can chemically react with calcium ions to produce high-purity struvite (MgNH4PO4•6H2O). Struvite is a high-quality slow-release fertilizer that can be directly applied to agricultural production, achieving effective recovery and reuse of phosphorus resources.

[0042] II) Membrane Distillation Apparatus The membrane distillation unit uses a hydrophobic PTFE (polytetrafluoroethylene) membrane with a pore size of 0.1-0.45 μm. During operation, the liquid to be treated is heated to 40-60°C, creating a vapor pressure difference on one side of the membrane. This allows water vapor to diffuse through the membrane pores from the high-pressure side to the low-pressure side, thus achieving liquid concentration and separation. The transmembrane pressure difference is controlled at 10-30 kPa to ensure the stability and efficiency of the membrane distillation process. The membrane distillation unit offers advantages such as high separation efficiency, low energy consumption, and simple operation, and can be used for recovering useful substances from wastewater or for advanced dehydration treatment.

[0043] (iii) Waste Heat Exchanger Waste heat exchangers are used to recover waste heat from exhaust gases generated during wastewater treatment. In processes such as anaerobic digestion, the equipment generates a large amount of high-temperature exhaust gas, which would be a waste of energy if directly discharged. Waste heat exchangers use the principle of heat exchange to transfer heat from the exhaust gas to media such as circulating water, raising the temperature of the circulating water. The heated circulating water can then be used to maintain the temperature of the anaerobic digester, reducing the energy consumption of heating equipment and achieving cascaded energy utilization and energy conservation and emission reduction.

[0044] The content of this invention is not limited to the embodiments listed. Any equivalent modifications made by those skilled in the art to the technical solutions of this invention by reading this specification are covered by the claims of this invention.

Claims

1. A modular high-concentration sewage treatment system, characterized in that: It includes a physicochemical pretreatment unit, a composite biodegradation unit, an electrochemical deep treatment unit, and a resource recycling unit; The physicochemical pretreatment unit is used to remove suspended solids from wastewater and break down the structure of organic matter in wastewater. The composite biodegradation unit includes an anaerobic ABR section and an aerobic MBBR section; The electrochemical deep treatment unit includes an electro-Fenton reaction cell, an ultraviolet disinfection module, and an intelligent control module. The resource recycling unit includes a sludge treatment unit and a resource recovery unit.

2. The modular high-concentration sewage treatment system according to claim 1, characterized in that: The physicochemical pretreatment unit includes a screw extrusion dewatering machine, which is connected to an ultrasonic cavitation reactor.

3. The modular high-concentration sewage treatment system according to claim 2, characterized in that: Polyethylene suspension packing is added to the aerobic section of the MBBR.

4. The modular high-concentration sewage treatment system according to claim 3, characterized in that: The ultraviolet disinfection module uses a low-pressure, high-intensity mercury lamp.

5. The modular high-concentration sewage treatment system according to claim 4, characterized in that: The sludge treatment unit includes a mesophilic anaerobic digester, a screw press dewatering machine, and a biogas purification device.

6. The modular high-concentration sewage treatment system according to claim 5, characterized in that: The resource recovery unit includes a crystallization reactor, a membrane distillation unit, and a waste heat exchanger.

7. A resource recycling method, characterized in that: Includes the following steps: Step S1: Pretreatment: spiral extrusion dehydration and ultrasonic cavitation treatment; Step S2: Combined biological reaction: anaerobic treatment and aerobic treatment; Step S3: Deep processing: electro-Fenton reaction, ultraviolet disinfection, and intelligent control module integrates IoT terminal, PLC controller and cloud server to build a data acquisition and control system; Step S4: Sludge treatment and resource recycling.

8. A resource recycling method according to claim 7, characterized in that: The biogas purification device uses a bio-trickling filter for desulfurization.

9. A resource recycling method according to claim 8, characterized in that: Waste heat exchangers are used to recover waste heat from exhaust gases generated during wastewater treatment.

10. A resource recycling method according to claim 9, characterized in that: Membrane distillation units can be used to recover useful substances from wastewater or to perform deep dewatering treatment.

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