Urban sewage resource recycling method

Abstract

The invention discloses an urban sewage resource recycling method, and relates to the technical field of water resource recovery, and the urban sewage resource recycling method comprises the following steps: S01, sewage pretreatment, S02, advanced oxidation pretreatment, S03, multi-stage electrochemical treatment, S04, intelligent control system, S05, waste heat recycling, S06, biological enhanced precipitation, and S07, precipitation treatment and resource utilization. As a pretreatment step, the advanced oxidation technology can generate hydroxyl free radicals (. OH) with high reaction activity, effectively destroy chemical bonds of organic matters and mineralize the organic matters into carbon dioxide and water or convert the organic matters into low-toxicity intermediate products, so that the biodegradability of the sewage is remarkably improved, and the sewage treatment efficiency is improved. And assistance is provided for subsequent electrochemical treatment, and the problem that in the prior art, the treatment efficiency of refractory organic matter is insufficient is solved.

Description

Technical Field

[0001] The invention relates to the technical field of water resource recovery, and in particular to a method for recovering and utilizing urban sewage as a resource. Background Art

[0002] In the current field of urban sewage treatment, with the rapid development of industrialization and urbanization, sewage treatment technology is facing higher and higher requirements. After searching, the Chinese patent publication number CN105776684B discloses a method for urban sewage treatment and resource recycling. Although this method reduces the production of sludge by more than 50%, and greatly removes the viscosity of the sludge, the waste residue will not be in a state of "mucous membrane wrapped in water", and it is easy to precipitate and filter press dewater, so that the water content of the sludge is reduced to less than 50%, solving the two major problems of "difficult to use effluent" and "toxic sludge siege", but this method may have the problem of incomplete treatment of refractory organic matter in sewage. Refractory organic matter includes persistent organic pollutants, industrial chemicals, and drug residues. These substances often pose a threat to the environment and human health, and traditional precipitation technology may be inefficient in treating sewage containing a large amount of fine suspended matter or colloidal substances, resulting in a high solid content in the effluent, affecting subsequent treatment steps and final water quality. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present invention provides a method for recycling and utilizing urban sewage resources, which solves the problem that the prior art mentioned in the background technology is deficient in removing difficult-to-degrade organic matter in sewage and the sedimentation efficiency may be insufficient, affecting the water quality.

[0004] To achieve the above purpose, the present invention is implemented by the following technical scheme: a method for recycling and utilizing urban sewage resources, the steps of which are as follows:

[0005] S01. Sewage pretreatment: The scattered urban sewage is collected through the municipal pipe network, and then the sand settling and slag removal treatment is carried out. The treated sewage is injected into the liquid collection tank, and the sewage is injected through the height difference or sewage pump to prepare for the subsequent electrochemical treatment; S02. Advanced oxidation pretreatment: Before the sewage enters the electrochemical treatment, the sewage is pretreated with advanced oxidation processes, including ozone, hydrogen peroxide, and photocatalysis, to destroy the structure of difficult-to-degrade organic matter, improve the biodegradability of sewage, and provide assistance for electrochemical treatment; S03. Multi-stage electrochemical treatment: The sewage flows from the liquid collection tank into the multi-stage electrolytic cell, and each Each electrolytic cell is equipped with electrodes, and the electrode materials are environmentally friendly materials, such as titanium substrate anodes coated with TiO2-RuO2 or metal anodes with precious metal coatings; the electrolytic cell is powered by a positive and negative DC power supply, and the voltage is controlled between 5 and 110V; the average residence time of sewage in the electrolytic cell is adjusted in real time according to the water quality to ensure that the pollutants are fully treated; during the electrolysis process, the strong oxidants produced by the chemical reaction of the chemical substances in the sewage and the electrode electric field are used to break the molecules, break the chains and open the rings, transform the structure, force degradation and deep treatment of the pollutants in the sewage, so as to achieve water and slag Rapid separation; S04. Intelligent control system: The entire electrochemical treatment process is monitored by an intelligent control system, which can monitor the water quality parameters of the sewage in real time, such as pH value, conductivity, and dissolved oxygen, and automatically adjust the voltage and treatment time of the electrolytic cell according to the monitoring results to optimize the treatment effect and ensure that the effluent quality is stable and meets the standards; S05. Waste heat recovery: During the electrochemical treatment process, the waste heat generated is used to preheat the sewage entering the system to reduce the overall energy consumption; the waste heat is recovered through the heat exchanger, and the preheated sewage enters the electrolytic cell for treatment; S06. Bio-enhanced precipitation: During the precipitation Microbial assisted sedimentation technology is introduced into the pool, and the flocculation effect of specific microorganisms is used to improve the sedimentation efficiency, further remove suspended matter and organic matter in sewage, and promote the stabilization of sludge; S07. Sedimentation treatment and resource utilization: The sewage after electrochemical treatment flows into the sedimentation tank, and the water and residue are separated and precipitated in the sedimentation tank. The clean liquid on the upper layer is continuously injected into the clean water storage tank through overflow, and then transported to the user through the water supply network; the sludge precipitated in the sedimentation tank is pumped out by a sludge suction pump, and then subjected to filter pressure treatment; the treated sludge is converted into biofuel or organic fertilizer by biological fermentation technology to achieve resource utilization.

[0006] Preferably, the pH adjustment range in S01 is adjusted to -7.5-9 by using a neutralizing regulator to adjust the pH value of the sewage; ensuring that the suspended solids (SS value) of the sewage is reduced to below -50 mg / L; the neutralizing regulator used includes one of sodium carbonate, sodium hydroxide, lime milk, sulfuric acid or hydrochloric acid.

[0007] Preferably, the ozone treatment method in S02 is:

[0008] a. Preparation of ozone generator: Start the ozone generator to generate ozone gas of the required concentration, ensuring that the ozone demand matches the sewage flow and CODcr concentration difference; b. Ozone dissolution: Effectively dissolve the ozone gas into the sewage through an ejector or aerator to form an ozone aqueous solution, ensuring the efficient dissolution of ozone in water; c. Oxidation reaction: In the mixing and reaction tank, the strong oxidizing property of ozone is used to destroy the difficult-to-degrade organic matter in the sewage and improve its biodegradability. The reaction time is optimized according to the sewage composition and treatment objectives.

[0009] Preferably, the hydrogen peroxide treatment method in S02 is:

[0010] a. Preparation of hydrogen peroxide: Determine the required amount of hydrogen peroxide based on the concentration and type of organic matter in the sewage; b. pH adjustment: Adjust the pH value of the sewage to the most effective reaction range of hydrogen peroxide, that is, an acidic environment of pH 3-5, to ensure that hydrogen peroxide can fully exert its oxidizing effect; c. Oxidation reaction: Under controlled conditions, add hydrogen peroxide for oxidation reaction to decompose organic pollutants in the sewage. The reaction conditions are optimized according to the specific sewage composition.

[0011] Preferably, the photocatalytic treatment method in S02 is:

[0012] a. Photocatalyst preparation: Select TiO2 or ZnO as the photocatalyst and load it evenly into the reactor. The amount of catalyst is 0.5-2.0 grams per liter to ensure sufficient photocatalytic activity; b. Light source setting: Select an ultraviolet (UV) light source with a wavelength range of 254-365 nanometers and set the light source intensity to 10-40 watts per square centimeter to ensure uniform light distribution and activate the photocatalyst; c. Photocatalytic reaction: Under light conditions, the photocatalyst activates oxidants such as hydrogen peroxide to produce strongly oxidizing hydroxyl radicals. The reaction time is set to 30-60 minutes to ensure sufficient degradation of organic matter. The light intensity is adjusted according to the specific situation to optimize the reaction rate and degradation efficiency.

[0013] Preferably, the effective volume of each electrolytic cell in the SO2 should be 1-5 cubic meters (m 3 ), the electrode material selected should be environmentally friendly, specifically a titanium substrate anode coated with a TiO2-RuO2 coating, or a metal anode containing precious metals (such as platinum and ruthenium) to ensure its corrosion resistance and conductivity, and the voltage of the electrolytic cell should be strictly controlled between 5-110 volts (V) to meet the treatment needs of different water qualities.

[0014] Preferably, the average residence time of the wastewater in the electrolytic cell should be set to 15-60 min, and the current density should be monitored during the electrolysis process and set at 10-50 mA / cm 2) to ensure the effective generation of strong oxidants; during the electrolysis process, the concentration of strong oxidants (such as hydroxyl radicals) should reach 0.1-1.0 milligrams per liter (mg / L) to achieve effective pollutant degradation.

[0015] Preferably, the microbial precipitation technology method in S06 is:

[0016] a. Microbial selection and cultivation: Select microorganisms with high-efficiency flocculation, such as Bacillus, Pseudomonas, and lactic acid bacteria; cultivate the selected microorganisms under laboratory conditions to obtain a high-density microbial population; b. Preparation of microbial flocculants: Prepare flocculants using microbial cells or their metabolites, control temperature, pH value, and nutrient factors through the fermentation process, and optimize the yield and performance of flocculants; c. Sewage adjustment: Adjust the pH value of sewage - the range of optimal microbial activity, which is a neutral or near-neutral environment; ensure that the nutrients in the sewage (such as carbon source, nitrogen source) meet the needs of microbial growth; d. Flocculant addition: Add the prepared flocculant to the wastewater; The prepared microbial flocculant is put into the sedimentation tank, and the dosage is adjusted according to the pollutant concentration and flocculation effect of the sewage; e. Sedimentation and separation: Through the action of microbial flocculants, the suspended matter and organic matter in the sewage are quickly aggregated into large-particle flocs; the flocs are separated from the water body by sedimentation or flotation; f. Sludge treatment: The precipitated sludge is dehydrated to reduce the volume and water content of the sludge; the dehydrated sludge can be further utilized as a resource, such as made into organic fertilizer or as a soil conditioner; g. Effect evaluation: The treatment effect of the microbial flocculant is evaluated by measuring the turbidity, COD, and SS indicators of the sewage.

[0017] Preferably, the sedimentation tank in S07 is divided into three areas: reaction area, sedimentation area, and water outlet area to ensure efficient separation; an inclined pipe is set in the sedimentation area to increase the surface hydraulic load, and the surface load of the inclined pipe is 12 to 25 m 3 / (㎡·h), the diameter of the inclined tube is 60-80mm, the inclination angle of the inclined tube is 60°, the filter belt tension of the sludge filter press is controlled at 0.3-0.7MPa, and the actual working speed of the filter belt is 3-6m / min.

[0018] The present invention provides a method for recycling and utilizing urban sewage resources. It has the following beneficial effects:

[0019] (1) Enhance the pretreatment efficiency of refractory organic matter: This method integrates advanced oxidation processes (AOPs), such as ozone (O3), hydrogen peroxide (H2O2), and photocatalysis (PC), as pretreatment steps to deeply oxidize refractory organic pollutants (such as polycyclic aromatic hydrocarbons, pesticides, drugs, and personal care products) in wastewater. These advanced oxidation technologies can produce highly reactive hydroxyl radicals (·OH), which effectively break the chemical bonds of organic matter, mineralize it into carbon dioxide and water, or convert it into low-toxic intermediates, thereby significantly improving the biodegradability of wastewater, providing assistance for subsequent electrochemical treatment, and solving the problem of insufficient treatment efficiency of refractory organic matter in existing technologies.

[0020] (2) Optimize energy management and improve energy efficiency: In the electrochemical treatment stage, this method uses a waste heat recovery system to recover the heat energy generated during the electrolysis process through a heat exchanger, which is used to preheat the sewage entering the treatment system, thereby realizing the cascade utilization of energy. In addition, the equipped intelligent control system can monitor and adjust the operating parameters of the electrolytic cell in real time, such as current density, voltage and electrolysis time, to adapt to changes in different water quality and treatment requirements, ensuring the maximization of treatment efficiency and minimization of energy consumption, thereby improving the energy utilization efficiency of the entire sewage treatment system.

[0021] (3) Promote the resource utilization and stabilization of sludge: In the sedimentation treatment stage, this method uses microbial assisted sedimentation technology to enhance the sedimentation efficiency of suspended solids and colloidal substances in the sedimentation tank by selectively adding or in situ cultivating microbial flora with high-efficiency flocculation characteristics. At the same time, the biological stabilization of sludge is promoted through bio-enhanced sedimentation technology, reducing sludge production and improving its dewatering performance. Subsequent sludge treatment uses bio-fermentation technology to convert dehydrated sludge into biofuel or organic fertilizer, realizing the resource utilization of sludge and improving the economy and environmental sustainability of sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1The embodiment of the present invention provides a technical solution: a method for recycling and utilizing urban sewage resources, the steps of which are as follows: S01. Sewage pretreatment: The dispersed urban sewage is collected through the municipal pipe network, and then the sand settling and slag removal treatment is performed. The treated sewage is injected into the liquid collection tank, and the sewage is injected through the height difference or sewage pump to prepare for the subsequent electrochemical treatment; S02. Advanced oxidation pretreatment: Before the sewage enters the electrochemical treatment, the sewage is pretreated by an advanced oxidation process, including ozone, hydrogen peroxide, and photocatalysis, to destroy the structure of the refractory organic matter, improve the biodegradability of the sewage, and provide auxiliary for the electrochemical treatment. S03. Multi-stage electrochemical treatment: sewage flows from the liquid collection tank into a multi-stage electrolytic cell, each electrolytic cell is equipped with electrodes, and the electrode materials are environmentally friendly materials, such as titanium substrate anodes coated with TiO2-RuO2 or metal anodes with precious metal coatings; the electrolytic cell is powered by a positive and negative DC power supply, and the voltage is controlled between 110V; the average residence time of sewage in the electrolytic cell is adjusted in real time according to the water quality to ensure that the pollutants are fully treated; during the electrolysis process, the strong oxidant produced by the chemical reaction of the chemical substances in the sewage and the electrode electric field is used to break the molecules, break the chains and open the rings, and structurally Conversion, forced degradation and deep treatment to achieve rapid separation of water and slag; S04. Intelligent control system: The entire electrochemical treatment process is monitored by an intelligent control system, which can monitor the water quality parameters of sewage in real time, such as pH value, conductivity, dissolved oxygen, and automatically adjust the voltage and treatment time of the electrolytic cell according to the monitoring results to optimize the treatment effect and ensure that the effluent quality is stable and meets the standards; S05. Waste heat recovery: During the electrochemical treatment process, the waste heat generated is used to preheat the sewage entering the system to reduce the overall energy consumption; the waste heat is recovered through the heat exchanger, and the preheated sewage enters the electrolytic cell for treatment; S06. Bio-enhanced sedimentation: Introduce microbial assisted sedimentation technology in the sedimentation tank, use the flocculation effect of specific microorganisms to improve sedimentation efficiency, further remove suspended matter and organic matter in sewage, and promote the stabilization of sludge; S07. Sedimentation treatment and resource utilization: The sewage that has been electrochemically treated flows into the sedimentation tank, and the water and residue are separated and precipitated in the sedimentation tank. The clean liquid on the upper layer is continuously injected into the clean water storage tank through overflow, and then transported to the user through the water supply network; the sludge precipitated in the sedimentation tank is pumped out by a sludge suction pump, and then subjected to filter pressure treatment; the treated sludge is converted into biofuel or organic fertilizer using biological fermentation technology to achieve resource utilization.

[0025] The pH adjustment range in S01 is to adjust the pH value of the sewage to 9 by using a neutralizing regulator; ensure that the suspended solids (SS value) of the sewage is reduced to below -50 mg / L; the neutralizing regulator used includes sodium carbonate.

[0026] The ozone treatment method in S02 is:

[0027] a. Preparation of ozone generator: Start the ozone generator to generate ozone gas of the required concentration, ensuring that the ozone demand matches the sewage flow and CODcr concentration difference; b. Ozone dissolution: Effectively dissolve the ozone gas into the sewage through an ejector or aerator to form an ozone aqueous solution, ensuring the efficient dissolution of ozone in water; c. Oxidation reaction: In the mixing and reaction tank, the strong oxidizing property of ozone is used to destroy the difficult-to-degrade organic matter in the sewage and improve its biodegradability. The reaction time is optimized according to the sewage composition and treatment objectives.

[0028] The hydrogen peroxide treatment method in S02 is:

[0029] a. Preparation of hydrogen peroxide: Determine the required amount of hydrogen peroxide based on the concentration and type of organic matter in the sewage; b. pH adjustment: Adjust the pH value of the sewage to the most effective reaction range of hydrogen peroxide, that is, an acidic environment of pH 3-5, to ensure that hydrogen peroxide can fully exert its oxidizing effect; c. Oxidation reaction: Under controlled conditions, add hydrogen peroxide for oxidation reaction to decompose organic pollutants in the sewage. The reaction conditions are optimized according to the specific sewage composition.

[0030] The photocatalytic treatment method in S02 is:

[0031] a. Photocatalyst preparation: Select TiO2 or ZnO as the photocatalyst and load it evenly into the reactor. The amount of catalyst is 2.0 grams per liter to ensure sufficient photocatalytic activity; b. Light source setting: Select an ultraviolet (UV) light source with a wavelength range of 365 nanometers and a light source intensity set to 40 watts per square centimeter to ensure uniform light distribution and activate the photocatalyst; c. Photocatalytic reaction: Under light conditions, the photocatalyst activates oxidants such as hydrogen peroxide to produce strongly oxidizing hydroxyl radicals. The reaction time is set to 60 minutes to ensure sufficient degradation of organic matter. The light intensity is adjusted according to the specific situation to optimize the reaction rate and degradation efficiency.

[0032] The effective volume of each electrolytic cell in S02 should be 5 cubic meters (m 3 ), the electrode material selected should be environmentally friendly, specifically a titanium substrate anode coated with a TiO2-RuO2 coating, or a metal anode containing precious metals (such as platinum and ruthenium) to ensure its corrosion resistance and conductivity, and the voltage of the electrolytic cell should be strictly controlled at 110 volts (V) to meet the treatment needs of different water qualities.

[0033] The average residence time of the wastewater in the electrolytic cell should be set at 60 min, and the current density should be monitored during the electrolysis process and set at 50 mA / cm 2) to ensure the effective generation of strong oxidants; during the electrolysis process, the concentration of strong oxidants (such as hydroxyl radicals) should reach 1.0 milligrams per liter (mg / L) to achieve effective pollutant degradation.

[0034] The microbial precipitation technology method in S06 is:

[0035] a. Microbial selection and cultivation: Select microorganisms with high-efficiency flocculation, such as Bacillus, Pseudomonas, and lactic acid bacteria; cultivate the selected microorganisms under laboratory conditions to obtain a high-density microbial population; b. Preparation of microbial flocculants: Prepare flocculants using microbial cells or their metabolites, control temperature, pH value, and nutrient factors through the fermentation process, and optimize the yield and performance of flocculants; c. Sewage adjustment: Adjust the pH value of sewage - the range of optimal microbial activity, which is a neutral or near-neutral environment; ensure that the nutrients in the sewage (such as carbon source, nitrogen source) meet the needs of microbial growth; d. Flocculant addition: Add the prepared flocculant to the wastewater; The prepared microbial flocculant is put into the sedimentation tank, and the dosage is adjusted according to the pollutant concentration and flocculation effect of the sewage; e. Sedimentation and separation: Through the action of microbial flocculants, the suspended matter and organic matter in the sewage are quickly aggregated into large-particle flocs; the flocs are separated from the water body by sedimentation or flotation; f. Sludge treatment: The precipitated sludge is dehydrated to reduce the volume and water content of the sludge; the dehydrated sludge can be further utilized as a resource, such as made into organic fertilizer or as a soil conditioner; g. Effect evaluation: The treatment effect of the microbial flocculant is evaluated by measuring the turbidity, COD, and SS indicators of the sewage.

[0036] The sedimentation tank in S07 is divided into three areas: reaction area, sedimentation area, and effluent area to ensure efficient separation; inclined pipes are set in the sedimentation area to increase the surface hydraulic load. The surface load of the inclined pipe is 25m 3 / (㎡·h), the diameter of the inclined tube is 80mm, the inclination angle of the inclined tube is 60°, the filter belt tension of the sludge filter press is controlled at 0.7MPa, and the actual working speed of the filter belt is 6m / min.

[0037] According to this method, different experimental parameters are recorded respectively, as shown in Table 1-3:

[0038] Table 1: Wastewater pretreatment and advanced oxidation treatment

[0039]

[0040] Table 2: Electrochemical treatment parameters

[0041]

[0042] Table 3: Sedimentation treatment and resource utilization

[0043]

[0044] From the advanced oxidation treatment data in Table 1, it can be seen that the ozone concentration, hydrogen peroxide dosage and photocatalyst dosage are all precisely controlled, which shows the accuracy and efficiency of the treatment process. For example, the ozone concentration of Sample 1 is 2.5 mg / L and the hydrogen peroxide dosage is 150 mg / L, which shows the high efficiency in destroying the refractory organic matter.

[0045] The electrochemical treatment parameters in Table 2 show that the adjustment of electrolytic cell volume, voltage and residence time reflects the adaptability and flexibility to different water qualities. For example, the electrolytic cell volume of Sample 1 is 3m 3 , voltage of 80V, and residence time of 30 minutes, optimization of these parameters helps ensure that the pollutants are adequately treated.

[0046] In summary, by precisely controlling the key parameters of pretreatment and electrochemical treatment, this method significantly improves the efficiency of sewage treatment and effluent quality, ensuring that the effluent quality stably meets the standards.

[0047] The waste heat temperature data in Table 2 show the effectiveness of the waste heat recovery system. For example, the waste heat temperature of Sample 1 is 50°C, which shows that the heat generated during the electrochemical treatment process is effectively recovered and used to preheat the sewage, reducing energy consumption.

[0048] The sedimentation treatment data in Table 3 show the efficiency of sludge treatment and resource utilization. For example, Sample 1 uses Bacillus for bioenhanced sedimentation, the flocculant dosage is 100 mg / L, and the surface hydraulic load of the sedimentation area is 15m 3 / (㎡·h), these measures help to improve sedimentation efficiency and promote sludge stabilization.

[0049] Through waste heat recovery and resource utilization of sludge, this method not only improves energy utilization efficiency, but also promotes environmentally friendly treatment of sludge, achieving sustainability and economic benefits of sewage treatment.

[0050] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0051] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for recycling urban sewage resources, characterized in that: The steps are as follows: S01. Sewage pretreatment: The dispersed urban sewage is collected through the municipal pipe network, and then the sand and slag are removed. The treated sewage is injected into the liquid collection tank, and the sewage is injected through the height difference or sewage pump to prepare for the subsequent electrochemical treatment; S02. Advanced oxidation pretreatment: Before the sewage enters the electrochemical treatment, the sewage is pretreated with advanced oxidation processes, including ozone, hydrogen peroxide, and photocatalysis, to destroy the structure of refractory organic matter, improve the biodegradability of the sewage, and provide assistance for electrochemical treatment; S03. Multi-stage electrochemical treatment: Sewage flows from the liquid collection tank into a multi-stage electrolytic cell. Each electrolytic cell is equipped with electrodes. The electrode materials are environmentally friendly materials, such as titanium substrate anodes coated with TiO2-RuO2 or metal anodes with precious metal coatings. The electrolytic cell is powered by a positive and negative DC power supply, and the voltage is controlled between 5 and 110V. The average residence time of sewage in the electrolytic cell is adjusted in real time according to the water quality to ensure that the pollutants are fully treated. During the electrolysis process, the strong oxidants produced by the electric field of the electrodes and the chemical reactions of the chemical substances in the sewage are used to break the molecules, break the chains and open the rings, transform the structures, force degradation and deep treatment of the pollutants in the sewage, so as to achieve rapid separation of water and slag. S04. Intelligent control system: The entire electrochemical treatment process is monitored by an intelligent control system, which can monitor the water quality parameters of sewage in real time, such as pH value, conductivity, and dissolved oxygen, and automatically adjust the voltage and treatment time of the electrolytic cell according to the monitoring results to optimize the treatment effect and ensure that the effluent quality is stable and meets the standards; S05. Waste heat recovery: During the electrochemical treatment process, the waste heat generated is used to preheat the sewage entering the system to reduce overall energy consumption; the waste heat is recovered through the heat exchanger, and the preheated sewage enters the electrolytic cell for treatment; S06. Bio-enhanced sedimentation: Introducing microbial-assisted sedimentation technology into the sedimentation tank, using the flocculation effect of specific microorganisms to improve sedimentation efficiency, further remove suspended solids and organic matter in sewage, and promote sludge stabilization; S07. Sedimentation treatment and resource utilization: The sewage after electrochemical treatment flows into the sedimentation tank, where the water and residue are separated and precipitated. The clean liquid on the upper layer is continuously injected into the clean water storage tank through overflow, and then transported to the user through the water supply network; the sludge precipitated in the sedimentation tank is pumped out by a sludge suction pump and then subjected to filter pressure treatment; the treated sludge is converted into biofuel or organic fertilizer by bio-fermentation technology to achieve resource utilization.

2. A method for recycling urban sewage as a resource according to claim 1, characterized in that: The pH adjustment range in S01 is adjusted to -7.5-9 by using a neutralizing regulator to reduce the pH value of the sewage to below -50 mg / L; the neutralizing regulator used includes one of sodium carbonate, sodium hydroxide, lime milk, sulfuric acid or hydrochloric acid.

3. The method for recycling urban sewage as a resource according to claim 1, characterized in that: The ozone treatment method described in S02 is: a. Preparation of ozone generator: Start the ozone generator to produce the required concentration of ozone gas, ensuring that the ozone demand matches the sewage flow and CODcr concentration difference; b. Ozone dissolution: ozone gas is effectively dissolved into sewage through an ejector or aerator to form an ozone aqueous solution, ensuring efficient dissolution of ozone in water; c. Oxidation reaction: In the mixing and reaction tanks, the strong oxidizing property of ozone is used to destroy the difficult-to-degrade organic matter in the sewage and improve its biodegradability. The reaction time is optimized according to the sewage composition and treatment objectives.

4. The method for recycling urban sewage as a resource according to claim 1, characterized in that: The hydrogen peroxide treatment method described in S02 is: a. Preparation of hydrogen peroxide: Determine the required amount of hydrogen peroxide based on the concentration and type of organic matter in the sewage; b. pH adjustment: adjust the pH value of the sewage to the most effective reaction range of hydrogen peroxide, that is, the acidic environment of pH 3-5, to ensure that hydrogen peroxide can fully exert its oxidizing effect; c. Oxidation reaction: Under controlled conditions, hydrogen peroxide is added to carry out oxidation reaction to decompose organic pollutants in sewage. The reaction conditions are optimized according to the specific sewage composition.

5. The method for recycling urban sewage as a resource according to claim 1, characterized in that: The photocatalytic treatment method in S02 is: a. Photocatalyst preparation: Select TiO2 or ZnO as the photocatalyst and load it evenly into the reactor. The amount of the catalyst is 0.5-2.0 g / L to ensure sufficient photocatalytic activity; b. Light source setting: Select an ultraviolet (UV) light source with a wavelength range of 254-365 nanometers and set the light source intensity to 10-40 watts per square centimeter to ensure uniform light distribution and activate the photocatalyst; c. Photocatalytic reaction: Under light conditions, photocatalysts activate oxidants such as hydrogen peroxide to produce strong oxidizing hydroxyl radicals. The reaction time is set to 30-60 minutes to ensure that organic matter is fully degraded. The light intensity is adjusted according to the specific situation to optimize the reaction rate and degradation efficiency.

6. The method for recycling urban sewage as a resource according to claim 1, characterized in that: The effective volume of each electrolytic cell in the SO2 should be 1-5 cubic meters (m 3 ), the electrode material selected should be environmentally friendly, specifically a titanium substrate anode coated with a TiO2-RuO2 coating, or a metal anode containing precious metals (such as platinum and ruthenium) to ensure its corrosion resistance and conductivity, and the voltage of the electrolytic cell should be strictly controlled between 5-110 volts (V) to meet the treatment needs of different water qualities.

7. The method for recycling urban sewage as a resource according to claim 1, characterized in that: The average residence time of the wastewater in the electrolytic cell should be set to 15-60 min, and the current density should be monitored during the electrolysis process and set at 10-50 mA / cm 2 ) to ensure the effective generation of strong oxidants; during the electrolysis process, the concentration of strong oxidants (such as hydroxyl radicals) should reach 0.1-1.0 milligrams per liter (mg / L) to achieve effective pollutant degradation.

8. The method for recycling urban sewage as a resource according to claim 1, characterized in that: The microbial precipitation technology method in S06 is: a. Microbial selection and cultivation: Select microorganisms with high-efficiency flocculation, such as Bacillus, Pseudomonas, and lactic acid bacteria; cultivate the selected microorganisms under laboratory conditions to obtain a high-density microbial population; b. Preparation of microbial flocculants: Flocculants are prepared using microbial cells or their metabolites, and the temperature, pH value, and nutrient factors are controlled during the fermentation process to optimize the yield and performance of the flocculants; c. Sewage adjustment: adjust the pH value of sewage - the range of optimal microbial activity, which is neutral or close to neutral environment; ensure that the nutrients in sewage (such as carbon source, nitrogen source) meet the needs of microbial growth; d. Flocculant addition: Add the prepared microbial flocculant into the sedimentation tank, and the dosage is adjusted according to the pollutant concentration of the sewage and the flocculation effect; e. Sedimentation and separation: Through the action of microbial flocculants, suspended solids and organic matter in sewage are quickly aggregated into large-particle flocs; the flocs are separated from the water body by sedimentation or flotation; f. Sludge treatment: Dewater the sludge after sedimentation to reduce its volume and moisture content; the dehydrated sludge can be further utilized as a resource, such as being made into organic fertilizer or used as a soil conditioner; g. Effect evaluation: Evaluate the treatment effect of microbial flocculants by measuring the turbidity, COD and SS indicators of sewage.

9. The method for recycling urban sewage as a resource according to claim 1, characterized in that: The sedimentation tank in S07 is divided into three areas: reaction area, sedimentation area, and water outlet area to ensure efficient separation; an inclined pipe is set in the sedimentation area to increase the surface hydraulic load. The surface load of the inclined pipe is 12 to 25 m 3 / (㎡·h), the diameter of the inclined tube is 60-80mm, the inclination angle of the inclined tube is 60°, the filter belt tension of the sludge filter press is controlled at 0.3-0.7MPa, and the actual working speed of the filter belt is 3-6m / min.

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