Integrated reverse osmosis treatment system for high organic wastewater

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to an integrated reverse osmosis treatment system for high organic wastewater. The method comprises the following steps: carrying out gravity settling treatment on organic wastewater to obtain primary treated wastewater; carrying out magnetic flocculation treatment on the primary treatment wastewater to obtain secondary treatment wastewater and flocculated sewage; performing microbial electrolysis treatment on the secondary treatment wastewater to obtain carbon dioxide and tertiary treatment wastewater; ozone is introduced into the tertiary treatment wastewater, catalytic ozonation treatment is carried out under the catalytic condition of a catalyst, organic pollutants in the tertiary treatment wastewater are degraded, and quaternary treatment wastewater is obtained. According to the invention, the concentration of organic pollutants and biological pollutants in the high-organic wastewater can be obviously reduced, so that pollutants attached to the surface of a reverse osmosis membrane used for subsequent reverse osmosis treatment are effectively reduced, and the risks of organic pollution blockage and biological pollution blockage of raw water are accurately reduced; the operation stability and the water treatment efficiency of the high-recovery-rate reverse osmosis system are obviously improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and particularly relates to an integrated reverse osmosis treatment system for high-organic wastewater. Background Art

[0002] Reverse osmosis membrane technology plays a key role in the treatment of high-organic-content wastewater such as refractory wastewater and industrial park wastewater by virtue of its characteristics of efficiently removing salts, organic matter, and pathogenic microorganisms in water. However, when treating such water sources with high organic matter content, the problem of biological fouling in the reverse osmosis membrane system is particularly intractable. Biological fouling refers to the attachment of microorganisms on the membrane surface and the formation of a biofilm. Over time, it will cause a sharp reduction in the flux of membrane elements and a rise in the transmembrane pressure difference, severely restricting the operation efficiency of the system. Such fouling not only increases the cleaning frequency and energy consumption, but also shortens the service life of the membrane, significantly pushing up the operation cost, and the contradiction is more prominent in high-recovery reverse osmosis systems - although high-recovery operation improves the water resource utilization rate, it intensifies the concentration effect of organic matter and microorganisms, accelerating the formation of biological fouling.

[0003] It is worth noting that when traditional pretreatment technologies are applied to the reverse osmosis pretreatment of organic wastewater with high organic matter content, it is difficult to effectively inhibit biological fouling and cannot effectively reduce the organic fouling and biological fouling of the reverse osmosis membrane. Facing the complex requirements of treating refractory wastewater and industrial park wastewater, the market needs a new type of pretreatment technology with both high treatment capacity and advantages of small footprint and integration to break through the bottleneck of traditional technologies, better cope with the problem of biological fouling in the treatment of water sources with high organic matter content, and help achieve the goal of near-zero discharge. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated reverse osmosis treatment system for high-organic wastewater. The reverse osmosis pretreatment method provided by the present invention can effectively reduce the attachment of pollutants on the reverse osmosis membrane surface, reduce the risks of organic fouling and biological fouling of the reverse osmosis membrane, significantly improve the operation stability and water treatment efficiency of the osmosis system, reduce energy consumption, reduce the maintenance frequency, and extend the service life of the membrane module.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] The present invention provides an organic wastewater reverse osmosis pretreatment method, including the following steps:

[0007] (1) Subject the organic wastewater to gravity sedimentation treatment to obtain primary treated wastewater;

[0008] (2) Subject the primary treated wastewater to magnetic flocculation treatment to obtain secondary treated wastewater and flocculated sewage. The magnetic flocculation treatment includes sequentially adding a coagulant, a magnetic mixing agent, and a coagulant aid to the primary treated wastewater, and then performing flocculation sedimentation;

[0009] (3) Perform microbial electrolysis treatment on the secondary treated wastewater to obtain carbon dioxide and tertiary treated wastewater;

[0010] (4) Introduce ozone into the tertiary treated wastewater and perform ozone catalytic oxidation treatment under the catalytic condition of a catalyst to degrade the organic pollutants in the tertiary treated wastewater and obtain quaternary treated wastewater.

[0011] Preferably, the coagulant includes polyaluminum chloride (PAC), and the mass ratio of the coagulant to the volume of the organic wastewater is (5 - 50) mg: 1 L;

[0012] The magnetic mixing agent includes magnetite, and the mass ratio of the magnetic mixing agent to the volume of the organic wastewater is (10 - 100) mg: 1 L;

[0013] The coagulant aid includes anionic polyacrylamide and / or non - ionic polyacrylamide, and the mass ratio of the coagulant aid to the volume of the organic wastewater is (1 - 10) mg: 1 L;

[0014] The pH value of the magnetic flocculation treatment is 6 - 7, and the pH value is adjusted by carbon dioxide during the magnetic flocculation treatment.

[0015] Preferably, after obtaining the flocculated sewage, it further includes: recovering the magnetic mixing agent from the flocculated sewage to obtain the recovered magnetic mixing agent and non - magnetic substances, and the recovered magnetic mixing agent is reused in step (2).

[0016] Preferably, after the microbial electrolysis treatment obtains carbon dioxide, it further includes using the carbon dioxide obtained from the microbial electrolysis treatment to adjust the pH value of the magnetic flocculation treatment.

[0017] Preferably, the microbial electrolysis treatment is carried out under the conditions of an anaerobic anode and an oxygen - supplying cathode. The microbial electrolysis treatment is carried out in a microbial electrolysis cell, which includes an anode chamber and a cathode chamber, and hydrogen is also generated in the cathode chamber.

[0018] Preferably, the content of total organic carbon (TOC) in the tertiary treated wastewater is 5 - 10 mg / L;

[0019] The mass ratio of the ozone to the total organic carbon in the tertiary treated wastewater is 0.5 - 1.5:1;

[0020] The catalyst is a supported catalyst, and the mass ratio of the catalyst to the ozone is 0.2 - 0.4:1;

[0021] The ozone catalytic oxidation treatment also obtains oxygen, and after obtaining oxygen, it further includes using the oxygen in the microbial electrolysis treatment.

[0022] The present invention provides a method for treating organic wastewater by reverse osmosis, comprising the following steps:

[0023] The four-stage treated wastewater obtained by the organic wastewater reverse osmosis pretreatment method described in the above technical solution is subjected to reverse osmosis treatment to obtain reverse osmosis pure water and reverse osmosis concentrated water.

[0024] Preferably, it further comprises: using a part of the reverse osmosis pure water in the microbial electrolysis treatment;

[0025] The conductivity of the reverse osmosis concentrated water is ≥20000 μs / cm, and the total dissolved solids (TDS) is ≥14000 mg / L;

[0026] The reverse osmosis concentrated water is subjected to energy recovery treatment, and the energy recovery treatment is to convert the water pressure of the reverse osmosis concentrated water into electric energy.

[0027] The present invention provides an organic wastewater reverse osmosis treatment system, comprising a sedimentation tank, a magnetic flocculation device, a microbial electrolysis cell, an ozone treatment device and a reverse osmosis device connected in sequence;

[0028] The magnetic flocculation device comprises a coagulation unit, a magnetic mixing unit, a coagulant aid unit and a sedimentation unit connected in sequence.

[0029] Preferably, a sludge discharge plate is provided at the bottom of the sedimentation tank, and the sludge discharge plate is used for discharging the sludge in the sedimentation tank;

[0030] The sedimentation unit is provided with a sewage discharge port;

[0031] The microbial electrolysis cell is provided with an anode chamber and a cathode chamber. The anode chamber is provided with an anode, and the anode chamber is provided with a gas outlet and a liquid inlet. The cathode chamber is provided with a cathode, and the cathode chamber is provided with a gas inlet, a liquid inlet and a gas outlet;

[0032] The ozone treatment device is provided with an oxygen outlet, and the oxygen outlet is communicated with the gas inlet of the cathode chamber;

[0033] The reverse osmosis device is provided with a water inlet, a pure water outlet and a concentrated water outlet, and a reflux pipeline is provided between the concentrated water outlet and the water inlet;

[0034] The organic wastewater reverse osmosis treatment system further comprises a magnetic powder recovery device, an energy recovery treatment device, a pure water storage tank and a hydrogen storage tank;

[0035] The inlet of the magnetic powder recovery device is communicated with the sewage discharge port of the sedimentation unit;

[0036] The inlet of the energy recovery treatment device is communicated with the concentrated water outlet of the reverse osmosis device;

[0037] The inlet of the pure water storage tank is connected to the pure water outlet of the reverse osmosis device;

[0038] The inlet of the hydrogen storage tank is connected to the gas outlet of the cathode chamber.

[0039] The present invention provides a method for reverse osmosis pretreatment of organic wastewater, comprising the following steps: (1) subjecting the organic wastewater to gravity sedimentation treatment to obtain primary treated wastewater; (2) subjecting the primary treated wastewater to magnetic flocculation treatment to obtain secondary treated wastewater and flocculated sewage, the magnetic flocculation treatment comprising sequentially adding a coagulant, a magnetic mixing agent and a coagulant aid to the primary treated wastewater, and then performing flocculation sedimentation; (3) subjecting the secondary treated wastewater to microbial electrolysis treatment to obtain carbon dioxide and tertiary treated wastewater; (4) introducing ozone into the tertiary treated wastewater and performing ozone catalytic oxidation treatment under the catalytic condition of a catalyst to degrade small molecular organic pollutants in the tertiary treated wastewater to obtain quaternary treated wastewater. The method for reverse osmosis pretreatment of organic wastewater provided by the present invention, before reverse osmosis treatment, by reasonably setting the pretreatment process and utilizing the synergistic effect of gravity sedimentation treatment, magnetic flocculation treatment, microbial electrolysis treatment and ozone catalytic oxidation treatment, can significantly reduce the concentrations of organic pollutants and biological pollutants in the organic wastewater, thereby effectively reducing the attachment of pollutants on the surface of the reverse osmosis membrane used in subsequent reverse osmosis treatment, accurately reducing the risks of organic fouling and biological fouling of the raw water, significantly improving the operation stability and water treatment efficiency of the high recovery rate reverse osmosis system, reducing energy consumption, reducing the maintenance frequency, prolonging the service life of the membrane module, providing a breakthrough solution for the efficient and stable operation of the high recovery rate reverse osmosis system. At the same time, the method for reverse osmosis pretreatment of organic wastewater provided by the present invention can realize the integration of the corresponding treatment system, has the advantages of small floor area, solves the problem of land shortage, and has both economic value and industry application prospectiveness. Description of the Drawings

[0040] Figure 1 It is a schematic structural diagram of the organic wastewater reverse osmosis treatment system provided by the present invention;

[0041] Figure 2 It is a working principle diagram of the sedimentation tank of the organic wastewater reverse osmosis treatment system provided by the present invention;

[0042] Figure 3 It is a schematic structural diagram of the magnetic flocculation device of the organic wastewater reverse osmosis treatment system provided by the present invention;

[0043] Figure 4 It is a working principle diagram of the microbial electrolytic cell of the organic wastewater reverse osmosis treatment system provided by the present invention;

[0044] Figure 5 It is a gas circuit diagram of the ozone treatment device of the organic wastewater reverse osmosis treatment system provided by the present invention;

[0045] Figure 6 This is the working principle diagram of the reverse osmosis device, pure water storage tank and energy recovery treatment device of the organic wastewater reverse osmosis treatment system provided by the present invention;

[0046] Figure 7 This is the working principle diagram of the magnetic powder recovery device of the organic wastewater reverse osmosis treatment system provided by the present invention;

[0047] In the figure: 1 is a sedimentation tank, 2 is a magnetic flocculation device, 3 is a microbial electrolytic cell, 4 is an ozone treatment device, 5 is a reverse osmosis device, 6 is a magnetic powder recovery device, 7 is an energy recovery treatment device, 8 is a pure water storage tank, and 9 is a hydrogen storage tank. Detailed implementation manners

[0048] The present invention provides an organic wastewater reverse osmosis pretreatment method, including the following steps:

[0049] (1) Subject the organic wastewater to gravity sedimentation treatment to obtain primary treated wastewater;

[0050] (2) Subject the primary treated wastewater to magnetic flocculation treatment to obtain secondary treated wastewater and flocculated sewage. The magnetic flocculation treatment includes sequentially adding a coagulant, a magnetic mixing agent and a coagulant aid to the primary treated wastewater, and then performing flocculation sedimentation;

[0051] (3) Subject the secondary treated wastewater to microbial electrolysis treatment to obtain carbon dioxide and tertiary treated wastewater;

[0052] (4) Pass ozone into the tertiary treated wastewater, and perform ozone catalytic oxidation treatment under the catalytic condition of a catalyst to degrade the organic pollutants in the tertiary treated wastewater to obtain quaternary treated wastewater.

[0053] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well-known to those skilled in the art.

[0054] The present invention subjects the organic wastewater to gravity sedimentation treatment to obtain primary treated wastewater. In the present invention, the organic wastewater is preferably high-organic-content wastewater. The mass concentration of suspended solids (SS) in the organic wastewater is preferably 50-200 mg / L; the TOC value in the organic wastewater is preferably 3000-10000 mg / L. The COD value in the organic wastewater is preferably 5000-20000 mg / L. The mass concentration of suspended solids (SS) in the primary treated wastewater is preferably 20-40 mg / L. The present invention can effectively remove the suspended solids in the organic wastewater through the gravity sedimentation.

[0055] In the present invention, the gravitational sedimentation is preferably carried out in a sedimentation tank. During the gravitational sedimentation process, the suspended solids in the organic wastewater gradually sink under the action of gravity, realizing the solid-liquid separation of the suspended solids in the organic wastewater, so as to obtain the primary treated wastewater.

[0056] After obtaining the primary treated wastewater, the present invention subjects the primary treated wastewater to magnetic flocculation treatment to obtain the secondary treated wastewater and flocculated sewage. The magnetic flocculation treatment includes sequentially adding a coagulant, a magnetic mixing agent and a coagulant aid to the primary treated wastewater, and then carrying out flocculation sedimentation. In the present invention, the magnetic flocculation treatment uses the synergistic action of the coagulant, the magnetic mixing agent and the coagulant aid, which can effectively remove the suspended solids (SS) and organic matter in the primary treated wastewater, and effectively reduce the chemical oxygen demand (COD) of the primary treated wastewater. In the present invention, after the magnetic flocculation treatment, the removal rate of the suspended solids (SS) in the primary treated wastewater is preferably 70-90%; the removal rate of organic matter is preferably 30-50%. The COD of the primary treated wastewater is reduced by 30-50%.

[0057] In the present invention, the coagulant preferably includes polyaluminum chloride (PAC). The mass ratio of the coagulant to the volume of the organic wastewater is preferably (5-50) mg: 1 L. In the present invention, the addition of the coagulant is carried out under stirring conditions. After the PAC is added to the primary treated wastewater, hydrolysis occurs, and the hydrolysis product is a positively charged colloid. The reaction principle is as follows:

[0058] Al n (OH) m Cl 3n-m +mH2O→nAl(OH)3(colloid)+(3n-m)Cl - ;

[0059] PAC neutralizes the negatively charged suspended particles (such as colloids and organic matter) in the primary treated wastewater to make them destabilized.

[0060] In the present invention, the magnetic mixing agent preferably includes magnetite. The mass ratio of the magnetic mixing agent to the volume of the organic wastewater is preferably (10-100) mg: 1 L. The magnetic mixing agent is preferably added under stirring conditions. After the magnetic mixing agent is added to the primary treated wastewater, high-density magnetic flocs are formed, increasing the density of the flocs and accelerating sedimentation. The present invention preferably controls the dosage of the magnetic mixing agent, which can effectively increase the density of the magnetic flocs, thereby accelerating the sedimentation of the magnetic flocs.

[0061] In the present invention, the coagulant aid preferably includes anionic polyacrylamide and / or non-ionic polyacrylamide. The mass ratio of the coagulant aid to the volume of the organic wastewater is preferably (1 - 10) mg: 1 L. In the present invention, the coagulant aid can polymerize small flocs into large and dense flocs through molecular chain bridging. By controlling the dosage of the coagulant aid, the present invention can effectively promote the aggregation of small particulate flocs floating in water. In the present invention, during the flocculation sedimentation process, magnetic flocs sediment to obtain secondary treated wastewater and flocculated sewage. The flocculated sewage contains magnetic flocs, which is also referred to as magnetic admixture flocculated sewage in the present invention.

[0062] In the present invention, the pH value of the magnetic flocculation treatment is preferably 6 - 7. The pH value of the magnetic flocculation treatment is preferably adjusted by carbon dioxide. The present invention preferably controls the pH of the magnetic flocculation treatment to be weakly acidic, which is more conducive to the generation and sedimentation of magnetic flocs. The present invention preferably introduces carbon dioxide into the primary treated wastewater to adjust the pH value in at least one of the following cases: before adding the coagulant, while adding the coagulant, after adding the coagulant and before adding the magnetic admixture, while adding the magnetic admixture, and after adding the magnetic admixture.

[0063] In the present invention, after obtaining the flocculated sewage, the present invention preferably further includes: recovering the magnetic admixture from the flocculated sewage to obtain the recovered magnetic admixture and non-magnetic substances. The recovered magnetic admixture is preferably recycled to the magnetic flocculation treatment for recycling. By recovering the magnetic admixture from the flocculated sewage and recycling the magnetic admixture, the present invention can effectively save costs.

[0064] In the present invention, the magnetic flocculation treatment greatly reduces the hydraulic retention time, and the floor area is only 1 / 20 of that of a conventional coagulation and flocculation tank, reducing the floor area of the system.

[0065] After obtaining the secondary treated wastewater, the present invention subjects the secondary treated wastewater to microbial electrolysis treatment to obtain carbon dioxide and tertiary treated wastewater. In the present invention, the microbial electrolysis treatment is preferably carried out in a microbial electrolysis cell. The microbial electrolysis cell preferably includes an anodic chamber and a cathodic chamber. An anode is provided in the anodic chamber, and a cathode is provided in the cathodic chamber. In the present invention, a support material is preferably provided in the anodic chamber. The support material is laid or fixed near the anode region, providing a growth carrier for microorganisms with electricity-producing ability and capable of colonizing on the anode surface, enabling the microorganisms to oxidize and decompose organic matter on its surface through an isoelectronic transfer medium. At the same time, relying on the good conductivity of the support material itself, it ensures the efficient transmission of electrons released by the decomposition of organic matter to the external circuit, realizes the effective export of electrons, guarantees the stable operation of the microbial electrolysis cell, and facilitates the material and energy conversion process of the entire system. In the present invention, the support material is preferably a carbon-based material, and the carbon-based material preferably includes carbon cloth and / or carbon paper. In the present invention, the material of the cathode is preferably ferrochromium alloy. The ferrochromium alloy has good conductivity,

[0066] The present invention preferably conveys the secondary treated wastewater to the anodic chamber for microbial electrolysis reaction under an externally applied load condition. In the present invention, the anode mainly utilizes electroactive microorganisms, such as Geobacter, Shewanella, etc. These microorganisms can colonize on the anode surface and have the ability of direct or indirect electron transfer to oxidize and decompose organic matter. The reaction principle is as follows: Under the action of microorganisms:

[0067] CH2O (general formula of organic matter) + H2O → CO2 + 4H + + 4e - ;

[0068] Release electrons and transfer them to the anode.

[0069] In the present invention, the support material of the anode preferably provides a carrier for the growth of the microorganisms and can also ensure the efficient transmission of electrons to the external circuit. In the present invention, the released electrons are transmitted to the cathode in the cathodic chamber through an external circuit power supply, and at the same time, H + is generated. In the present invention, after the cathodic chamber produces H + , hydrogen is obtained in the cathodic chamber, and the reaction is as follows:

[0070] 2H + + 2e - → H₂↑.

[0071] In the present invention, the hydrogen generated during the microbial electrolysis treatment is preferably conveyed to a hydrogen storage tank.

[0072] In the present invention, after the organic matter in the secondary treated wastewater is decomposed, the concentration of the organic matter is reduced, and tertiary treated wastewater is obtained.

[0073] In the present invention, after the carbon dioxide is obtained by the microbial electrolysis treatment, the present invention preferably further comprises using the carbon dioxide obtained by the microbial electrolysis treatment for pH adjustment in the magnetic flocculation treatment.

[0074] In the present invention, the microbial electrolysis treatment is carried out under the condition of introducing oxygen. The oxygen is preferably introduced into the cathode chamber for reaction. The microbial electrolysis treatment also produces hydrogen.

[0075] In the present invention, the total organic carbon (TOC) content in the tertiary treated wastewater is preferably 5 to 10 mg / L.

[0076] In the present invention, the microbial electrolysis treatment process achieves the dual-functional coupling of pollutant degradation and energy recovery. While efficiently degrading organic matter, the microbial electrolysis treatment process drives electron transfer to form electric current through microbial metabolism, thus constructing a green treatment system that does not require additional high-intensity energy input. The present invention fully utilizes the direct participation of microorganisms in sludge in electron transfer, breaking through the limitation of traditional sewage treatment that only aims at pollutant removal. The present invention has created a new path of "bioelectrochemical synergistic transformation" in sewage resource utilization, providing a solution for the treatment of high-concentration organic wastewater with both environmental benefits and energy value.

[0077] After obtaining tertiary treated wastewater, the present invention introduces ozone into the tertiary treated wastewater and performs ozone catalytic oxidation treatment under catalytic conditions of a catalyst to degrade organic pollutants in the tertiary treated wastewater, thereby obtaining quaternary treated wastewater. In the present invention, the total organic carbon (TOC) content in the tertiary treated wastewater is preferably 5 to 10 mg / L. The ratio of the mass of the ozone to the mass of the total organic carbon in the tertiary treated wastewater is preferably 0.5 to 1.5:1. The catalyst is preferably a metal oxide or a supported catalyst, and the carrier of the supported catalyst is preferably TiO2 and / or Al2O3. The mass ratio of the catalyst to the ozone is preferably 0.2 to 0.4:1. In the present invention, the principle of the ozone catalytic oxidation treatment is to utilize the strong oxidizing properties of ozone (O3) to achieve pollutant degradation under the action of a catalyst. Specifically, the catalyst promotes the decomposition of ozone to generate hydroxyl radicals (·OH) with strong oxidizing properties, thereby achieving efficient degradation of organic pollutants. In the present invention, the ozone catalytic oxidation treatment is a heterogeneous catalytic oxidation. The catalyst used in the present invention is insoluble in water and has good stability and recyclability.

[0078] In the present invention, the ozone catalytic oxidation treatment is divided into three stages: First, after ozone is dissolved in the liquid phase, it is adsorbed and activated by the catalyst to generate hydroxyl radicals; Second, organic pollutants are adsorbed on the surface of the catalyst to form surface chelates; Finally, the hydroxyl radicals react with the surface chelates to degrade the organic pollutants. The chemical reactions involved in the ozone catalytic oxidation treatment mainly include the decomposition of ozone under the action of the catalyst to generate hydroxyl radicals:

[0079] O3 + M (catalyst) → ·OH + O2 + M;

[0080] And the reaction of hydroxyl radicals with organic substances (represented by R-H for organic substances):

[0081] ·OH + R-H → R· + H2O.

[0082] Through the ozone catalytic oxidation treatment of the present invention, the catalyst is used to catalyze the decomposition of ozone to generate ·OH, which oxidizes and degrades the pollutants in water. Thus, the present invention can more effectively reduce the concentration of organic substances entering the subsequent reverse osmosis process.

[0083] In the present invention, after the ozone catalytic oxidation treatment, the concentration of organic substances in the tertiary-treated wastewater is reduced by 40-70%. And the concentration of small-molecule organic substances that are difficult to degrade in the water body is greatly reduced.

[0084] In the present invention, the ozone catalytic oxidation treatment also produces oxygen. After obtaining oxygen, the present invention preferably further includes using the oxygen in the microbial electrolysis treatment.

[0085] The present invention provides a method for reverse osmosis treatment of organic wastewater, including the following steps:

[0086] Perform reverse osmosis treatment on the four-stage treated wastewater obtained by the organic wastewater reverse osmosis pretreatment method described in the above technical solution to obtain reverse osmosis pure water and reverse osmosis concentrate.

[0087] In the present invention, the reverse osmosis treatment is carried out in a reverse osmosis device. In the reverse osmosis treatment, by applying pressure, water molecules pass through the semipermeable membrane of the reverse osmosis device, thereby effectively removing dissolved salts, microorganisms, and other impurities in the water.

[0088] In the present invention, the pressure of the reverse osmosis treatment is preferably 5-15 Bar.

[0089] In the present invention, the TDS of the reverse osmosis pure water is preferably ≤50 mg / L, the conductivity is preferably ≤100 μS / cm, the pH is preferably 6.5-7.5, the TOC is preferably 0.5-1 mg / L, and the microbial index is preferably: the total number of bacteria ≤10 CFU / mL.

[0090] The reverse osmosis treatment preferably adopts a full return mode of concentrated water until the conductivity of the reverse osmosis concentrated water is preferably ≥20,000 μs / cm, which is 20,000 μs / cm in the embodiment, and the total dissolved solids (TDS) is preferably ≥14,000 mg / L, which is 14,000 mg / L in the embodiment. Then the reverse osmosis concentrated water is discharged.

[0091] The present invention adopts a full return operation mode of concentrated water for reverse osmosis treatment, which can enhance the overall operation efficiency of the system. When the concentration of the concentrated water rises to the set threshold, the present invention preferably discharges the concentrated water to prevent membrane pollution and scaling.

[0092] In the present invention, after obtaining the reverse osmosis pure water, the present invention preferably further includes: using part of the reverse osmosis pure water in the microbial electrolysis treatment for hydrogen generation. The remaining reverse osmosis pure water is preferably stored in a pure water tank. The present invention preferably utilizes the reverse osmosis pure water according to the requirements of the reverse osmosis treatment and uses it as a water source for different purposes.

[0093] In the present invention, the discharged reverse osmosis concentrated water is preferably subjected to energy recovery treatment, and the energy recovery treatment is preferably to convert the water pressure of the reverse osmosis concentrated water into electric energy.

[0094] The present invention provides an organic wastewater reverse osmosis treatment system, including a sedimentation tank, a magnetic flocculation device, a microbial electrolysis cell, an ozone treatment device, and a reverse osmosis device connected in sequence;

[0095] The magnetic flocculation device includes a coagulation unit, a magnetic mixing unit, a coagulant aid unit, and a sedimentation unit connected in sequence.

[0096] The organic wastewater reverse osmosis treatment system provided by the present invention includes a sedimentation tank. In the present invention, the sedimentation tank includes an inlet and an outlet. In the present invention, the working principle of the sedimentation tank is based on gravity sedimentation. When the organic wastewater enters the sedimentation tank, the suspended solids in the water gradually sink due to gravity and accumulate at the bottom of the tank, and the clear water flows out from the outlet, realizing solid-liquid separation.

[0097] In the present invention, the number of the sedimentation tanks is preferably 2, namely the first sedimentation tank and the second sedimentation tank. The two sedimentation tanks are preferably connected in parallel. A sludge discharge plate is arranged at the bottom of the sedimentation tank, and the sludge discharge plate is used to discharge the sludge in the sedimentation tank. The material of the sludge discharge plate is preferably a corrosion-resistant material.

[0098] In the present invention, the operation mode of the sedimentation is preferably as follows: the organic wastewater continuously flows into the sedimentation tank, the suspended solids continuously settle, and the sludge gradually accumulates at the bottom of the tank; when the sludge accumulates to a certain extent, the water inlet of the sedimentation tank is suspended, and the internal sludge discharge plate is energized and starts to rotate, pushing out the sludge accumulated at the bottom of the sedimentation tank to complete the sludge discharge operation; then the sludge discharge plate rotates back to the original position, the sedimentation tank resumes water inlet, and the sedimentation treatment continues.

[0099] In the present invention, when the sludge discharge plate of the first sedimentation tank is working, the sludge discharge plate of the second sedimentation tank is stationary; when the sludge discharge plate of the second sedimentation tank is working, the sludge discharge plate of the first sedimentation tank is stationary.

[0100] In the present invention, the sedimentation tank efficiently separates the suspended solids in the organic wastewater through gravity sedimentation, reduces the pollutant load of the subsequent treatment unit, and ensures the stability of the overall treatment process. Two sedimentation tanks are connected in parallel in the present invention, which can continuously treat sewage and improve the sewage purification efficiency.

[0101] In the present invention, a sludge discharge plate is arranged in the sedimentation tank, and the sludge discharge can be automatically completed without frequent manual intervention, which not only reduces the time cost of equipment shutdown for sludge discharge, but also ensures the continuity of the sedimentation process, improves the stability and convenience of the operation of the sedimentation tank, and optimizes the overall efficiency of sewage treatment.

[0102] In the present invention, the sludge discharge plate is preferably arranged at the bottom of the sedimentation tank shown. The sludge discharge plate is preferably arranged at the bottom of the sedimentation tank near the sludge collection hopper or the sludge collection area with a lower slope at the bottom of the tank. This position is convenient for directly contacting the settled sludge, and the sludge collection and pushing can be realized by the rotational movement of the sludge discharge plate.

[0103] In the present invention, the settled sludge gradually accumulates at the bottom of the tank above the sludge discharge plate, and the sludge discharge plate is located below the sludge layer or in direct contact with it. When the sludge discharge plate rotates, it can directly push or scrape the accumulated sludge above, making it move towards the sludge discharge port.

[0104] In the present invention, after the organic wastewater enters, the sludge settles towards the bottom of the tank under the action of gravity and gradually accumulates at the area with a lower slope at the bottom of the sedimentation tank or the sludge collection hopper. These areas are the final gathering points of the sludge gravity sedimentation, and the present invention facilitates the centralized collection and discharge by setting the sludge discharge plate.

[0105] In the present invention, the sludge discharge plate preferably makes a circular motion around a fixed axis, and is usually driven by a motor through a transmission device to achieve timed or continuous rotation. The fixed axis preferably includes a central axis or a side axis.

[0106] In the present invention, the shape of the sludge discharge plate preferably includes a sector shape, an arc shape or a flat plate shape. The material of the sludge discharge plate is preferably stainless steel, high-density polyethylene (HDPE) or polyvinyl chloride (PVC), ensuring stable operation in the wastewater environment for a long time.

[0107] In the present invention, the edge of the sludge discharge plate preferably has an inclined angle to enhance the sludge pushing effect.

[0108] In the present invention, a sludge scraping blade is preferably provided at the edge of the sludge discharge plate to enhance the sludge pushing effect.

[0109] In the present invention, the sludge discharge plate preferably adheres closely to the bottom of the pool, but a tiny gap is reserved. When the sludge discharge plate rotates, the accumulated sludge is scraped up from the bottom of the pool and pushed to the sludge discharge port by using the angle between the plate body and the bottom of the pool. The sludge is discharged out of the pool through the sludge discharge pipeline of the sedimentation tank.

[0110] In the present invention, the sludge discharge plate preferably combines gravity sludge discharge or pump suction sludge discharge to ensure efficient removal of sludge and maintain the separation effect of the sedimentation tank.

[0111] The organic wastewater reverse osmosis treatment system provided by the present invention includes a magnetic flocculation device communicated with the water outlet of the sedimentation tank. In the present invention, the magnetic flocculation device includes a coagulation unit, a magnetic mixing unit, a coagulant aid unit, and a sedimentation unit that are communicated in sequence.

[0112] In the present invention, the coagulation unit is preferably a coagulation tank. The magnetic mixing unit is preferably a magnetic mixing tank. The coagulant aid unit is preferably a coagulant aid tank, and the sedimentation unit is preferably a sedimentation tank.

[0113] In the present invention, after the water discharged from the sedimentation tank passes through the magnetic flocculation device, first, the primary treated sewage obtained from the sedimentation tank flows from the sedimentation tank into the coagulation tank, and a coagulant is added and stirred to generate a positively charged colloid after hydrolysis, and the negatively charged suspended particles (such as colloids and organic matters) in the sewage are neutralized by the reaction to make them destabilized; then the water flows into the magnetic mixing tank, and a magnetic mixing agent (such as Fe3O4) is added and stirred to form high-density magnetic flocs, increasing the density of the flocs to accelerate sedimentation; then it enters the coagulant aid tank, and a coagulant aid is added, and small flocs can be polymerized into large and dense flocculates through molecular chain bridging; the mixed liquid flows into the sedimentation tank, and the clarified water is discharged to the microbial electrolytic cell after the magnetic flocs settle. In the present invention, a sewage discharge port is provided in the sedimentation unit, and the sewage with magnetic mixing agent flocculated at the bottom flows to the magnetic powder recovery device. The magnetic mixing agent will flow back into the magnetic mixing tank through a reflux pump, and the non-magnetic substances are discharged as sewage. The magnetic mixing agent adsorbed by the magnetic powder recovery device is detached from the magnetic field through backwashing and circulated to the magnetic mixing tank.

[0114] In the present invention, the carbon dioxide generated in the anode chamber of the microbial electrolytic cell is introduced into the magnetic flocculation device, which can adjust the pH of the wastewater to weakly acidic, facilitating the acceleration of floc generation.

[0115] The magnetic flocculation device provided by the present invention improves the removal rates of SS and COD while shortening the sedimentation time. In terms of cost control, the present invention can maximize the recycling and utilization of the magnetic admixture, thereby saving costs. The organic wastewater reverse osmosis treatment system provided by the present invention realizes a magnetic admixture recycling mode, and the coagulant, magnetic admixture, and system are constructed using a modular assembly design. The modular assembly design is further adopted, which is conducive to rapid construction and convenient for flexible expansion in the later stage.

[0116] The organic wastewater reverse osmosis treatment system provided by the present invention comprises a microbial electrolysis cell connected to the water outlet of the magnetic flocculation device.

[0117] In the present invention, the microbial electrolysis cell is provided with an anode chamber and a cathode chamber, the anode chamber is provided with an anode, the anode chamber is provided with a gas outlet and a liquid inlet, the cathode chamber is provided with a cathode, the cathode chamber is provided with a gas inlet, a liquid inlet and a gas outlet.

[0118] In the present invention, the secondary treated wastewater is transported to the anode chamber of the microbial electrolysis cell, and the reverse osmosis pure water is passed into the cathode chamber of the microbial electrolysis cell.

[0119] In the present invention, the anode chamber mainly utilizes electroactive microorganisms, which can colonize on the surface of the support material in the anode chamber, oxidize organic matter in the wastewater (such as glucose, acetic acid, COD in sewage), and release electrons (e - ) and protons (H + The anode is provided with a supporting material, and the supporting material is a carbon-based material (such as carbon cloth, carbon paper) as a supporting material, which not only provides a carrier for the growth of microorganisms, but also ensures that electrons are efficiently transmitted to the external circuit. The released electrons are transmitted to the chemical cathode through the external circuit power supply, and H + The generated carbon dioxide is supplied to the magnetic flocculation device for adjusting the pH value in the magnetic flocculation device. In the present invention, after the organic matter in the influent of the magnetic flocculation device is decomposed, the secondary treated wastewater with reduced organic matter concentration flows into the anode of the microbial electrolysis cell and then enters the ozone processor for treatment.

[0120] The reverse osmosis treatment system for organic wastewater provided by the present invention includes an ozone treatment device connected to the water outlet of the microbial electrolysis cell. In the present invention, the ozone treatment device is provided with an oxygen outlet, and the oxygen outlet is connected to the gas inlet of the cathode chamber. In the present invention, the ozone treatment device is preferably provided with a gas-water contact device. The gas-water contact device preferably includes a microporous diffuser or a bubble tower. The ozone is fully contacted with the tertiary treated wastewater through the gas-water contact device, and at the same time, the catalyst is used to catalyze the decomposition of ozone to produce ·OH, which oxidizes and degrades pollutants in the water. Therefore, the concentration of organic matter entering the subsequent reverse osmosis process with a controllable recovery rate can be more effectively reduced.

[0121] The reverse osmosis treatment system for organic wastewater provided by the present invention includes a reverse osmosis device communicated with the water outlet of the ozone treatment device. In the present invention, the reverse osmosis device is provided with a water inlet, a pure water outlet and a concentrated water outlet, and a reflux pipeline is provided between the concentrated water outlet and the water inlet.

[0122] In the present invention, the reverse osmosis device makes water molecules pass through the semi-permeable membrane by applying pressure, thereby effectively removing dissolved salts, microorganisms and other impurities in the water. The reverse osmosis device is provided with a recovery control mechanism, which can optimize the water recovery rate while ensuring water quality and improve the water production efficiency. The reverse osmosis device is preferably provided with a concentrated water circulation structure, so that the concentrated water flows back to the water inlet end to enhance the overall operation efficiency of the system and reduce the floor area at the same time. When the concentration of the concentrated water rises to the set threshold, the valve in the system will automatically open to discharge the concentrated water to prevent membrane pollution and scaling.

[0123] The reverse osmosis treatment system for organic wastewater provided by the present invention preferably includes a magnetic powder recovery device. The inlet of the magnetic powder recovery device is communicated with the sewage discharge port of the precipitation unit.

[0124] In the present invention, the magnetic powder recovery device receives the wastewater from the magnetic flocculation device. The wastewater from the magnetic flocculation device mainly contains a magnetic mixing agent (the main component is Fe3O4).

[0125] In the present invention, the magnetic powder recovery and treatment device preferably recovers magnetic powder. The sludge obtains magnetic powder through a magnetic separator and re-adds it to the magnetic flocculation treatment process as a magnetic mixing agent, realizing the recycling of magnetic powder, reducing the operation cost, and enhancing the environmental sustainability of the system.

[0126] The reverse osmosis treatment system for organic wastewater provided by the present invention preferably includes an energy recovery and treatment device. The inlet of the energy recovery and treatment device is communicated with the concentrated water outlet of the reverse osmosis device.

[0127] The reverse osmosis treatment system for organic wastewater provided by the present invention preferably includes a pure water storage tank. The inlet of the pure water storage tank is communicated with the pure water outlet provided by the reverse osmosis device.

[0128] The reverse osmosis treatment system for organic wastewater provided by the present invention preferably includes a hydrogen storage tank. In the present invention, the inlet of the hydrogen storage tank is communicated with the gas outlet of the cathode chamber.

[0129] In order to further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below in conjunction with embodiments, but they cannot be understood as limiting the protection scope of the present invention.

[0130] Example 1

[0131] This embodiment provides a method for treating organic wastewater by reverse osmosis, using the Figure 1 organic wastewater reverse osmosis treatment system shown, including the following steps

[0132] Figure 2 is the structural and working principle diagram of the sedimentation tank in this embodiment. High organic wastewater (the mass concentration of SS is 200 mg / L, TOC is preferably 10,000 mg / L, and COD is 20,000 mg / L) flows into the sedimentation tank. The sedimentation tank uses the first sedimentation tank and the second sedimentation tank in parallel. The suspended solids in the organic wastewater gradually sink due to gravity and accumulate at the bottom of the tank, while the clear water flows out from above to achieve solid-liquid separation. The primary treated wastewater is obtained. The mass concentration of SS in the primary treated wastewater is 40 mg / L.

[0133] Figure 3 is the structural and working principle diagram of the magnetic flocculation device in this embodiment. The primary treated wastewater enters the magnetic flocculation device. First, the primary treated wastewater flows from the sedimentation tank into the coagulation tank, and a coagulant (PAC, the mass ratio of the coagulant to the volume of the organic wastewater is 10 mg: 1 L) is added. After stirring, a positively charged colloid is generated after hydrolysis, and the negatively charged suspended particles (such as colloids and organic matters) in the sewage are neutralized by the reaction to make them destabilized; then the primary treated wastewater flows into the magnetic mixing tank, and a magnetic mixing agent (Fe3O4, the mass ratio of the magnetic mixing agent to the volume of the organic wastewater is 20 mg: 1 L) is added and stirred to form high-density magnetic flocs, increasing the density of the flocs to accelerate sedimentation; then the primary treated wastewater enters the coagulant aid tank, and a coagulant aid (anionic polyacrylamide, the mass ratio of the coagulant aid to the volume of the organic wastewater is 5 mg: 1 L) is added, which can polymerize small flocs into large and dense flocs through molecular chain bridging; the mixed liquid flows into the sedimentation tank, and after the magnetic flocs settle, the clarified water is discharged to the microbial electrolytic cell, and the magnetic powder flocculated sewage at the bottom flows to the magnetic powder recovery device ( Figure 7 ), the magnetic mixing agent will flow back into the magnetic mixing tank through the reflux pump, and the non-magnetic substances are discharged as sewage. The magnetic powder adsorbed by the magnetic powder recovery device is detached from the magnetic field through backwashing and circulated to the magnetic mixing tank. In this embodiment, the carbon dioxide generated at the anode of the microbial electrolytic cell is introduced into the magnetic mixing tank to adjust the pH of the primary treated wastewater to 6-7, which is beneficial to accelerating the generation of flocs.

[0134] After magnetic flocculation treatment, the secondary treated wastewater is obtained. In this embodiment, after magnetic flocculation treatment: the removal rate of suspended solids (SS) in the primary treated wastewater is 90%; the removal rate of organic matters is 50%. The COD of the primary treated wastewater is reduced by 50%.

[0135] Figure 4 is the working principle diagram of the microbial electrolytic cell of the organic wastewater reverse osmosis treatment system provided by the present invention. The secondary treated wastewater is transported to the anode chamber. The pure water generated by the reverse osmosis device is stored in the pure water storage tank and flows from the pure water storage tank to the cathode chamber.

[0136] The anodic chamber mainly utilizes microorganisms with electricity-generating ability to oxidize and decompose organic substances, release electrons and transfer them to the anode. The electrons are efficiently transmitted to the external circuit. The released electrons are transmitted to the cathode through the external circuit power supply, and at the same time, H + is generated. The carbon dioxide produced in the anodic chamber is supplied to the magnetic flocculation device to adjust the pH value in the magnetic flocculation device. After the organic substances in the secondary-treated wastewater are decomposed, the tertiary-treated wastewater with a reduced concentration of organic substances in the water enters the ozone processor for treatment. The content of total organic carbon (TOC) in the tertiary-treated wastewater is 5 mg / L.

[0137] Figure 5 It is the gas circuit diagram of the ozone treatment device of the organic wastewater reverse osmosis treatment system provided by the present invention. The tertiary-treated wastewater enters the ozone treatment device, and the mass ratio of ozone to the total organic carbon in the tertiary-treated wastewater is 1:1. The catalyst is a metal oxide, and the mass ratio of the catalyst to ozone is 0.3:1. Ozone diffuses into the tertiary-treated wastewater through the gas-liquid contact device (microporous diffuser) provided in the ozone treatment device, fully contacts the tertiary-treated wastewater, and at the same time uses the catalyst to catalyze the decomposition of ozone to generate ·OH, oxidize and degrade the pollutants in the tertiary-treated wastewater, and obtain the quaternary-treated wastewater. After ozone catalytic oxidation treatment, the concentration of organic substances in the tertiary-treated wastewater is reduced by 70%.

[0138] Figure 6 It is the working principle diagram of the reverse osmosis device, pure water storage tank and energy recovery treatment device of the organic wastewater reverse osmosis treatment system provided by the present invention. The water molecules in the quaternary-treated wastewater pass through the reverse osmosis membrane (semipermeable membrane), thereby effectively removing the dissolved salts, microorganisms and other impurities in the quaternary-treated wastewater. The reverse osmosis device is equipped with a recovery control mechanism, which can optimize the water recovery rate while ensuring water quality and improve the water production efficiency. The reverse osmosis device adopts a circulating structure, enabling the concentrated water to flow back to the inlet end to enhance the overall operation efficiency of the system. When the concentration of the concentrated water rises to the set threshold (conductivity is 20000 μs / cm, TDS is 14000 mg / L), the valves in the system will automatically open to discharge the concentrated water to prevent membrane fouling and scaling.

[0139] The pure water purified by the reverse osmosis system is transported to the pure water storage tank for storage. In the embodiment, the TDS of the obtained reverse osmosis pure water ≤ 50 mg / L, the conductivity ≤ 100 μS / cm, the pH is 6.5 - 7.5, the TOC is 0.5 - 1 mg / L, and the microbial index is: the total number of bacteria ≤ 10 CFU / mL.

[0140] The concentrated water then passes through the energy recovery device, and the residual pressure energy in it is recovered in the energy recovery device for the operation of the microbial electrolytic cell, improving the energy efficiency of the overall system. This process realizes the collaborative recovery and recycling of water resources and energy.

[0141] In this embodiment, the magnetic powder recovery device receives the wastewater from the magnetic flocculation device. The wastewater from the magnetic flocculation device mainly contains magnetic mixing agent (magnetite). The magnetic powder is separated by using a magnetic separator so that the magnetic powder can be reused as a magnetic mixing agent. This embodiment realizes the recycling of iron resources, reduces the operating cost, and improves the environmental sustainability of the system.

[0142] As can be seen from the above embodiments, before the reverse osmosis treatment, by reasonably setting the pretreatment process and utilizing the synergistic effects of gravity sedimentation treatment, magnetic flocculation treatment, microbial electrolysis treatment and ozone catalytic oxidation treatment, the concentrations of organic pollutants and biological pollutants in the organic wastewater can be significantly reduced. Thus, the attachment of pollutants on the surface of the reverse osmosis membrane used in the subsequent reverse osmosis treatment can be effectively reduced, the risks of organic fouling and biological fouling of the raw water can be accurately reduced, the operating stability and water treatment efficiency of the high-recovery reverse osmosis system can be significantly improved, the energy consumption can be reduced, the maintenance frequency can be decreased, the service life of the membrane module can be extended, and a breakthrough solution for the efficient and stable operation of the high-recovery reverse osmosis system can be provided, which has both economic value and industry application prospectiveness.

[0143] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, rather than all embodiments. Other embodiments can be obtained according to this embodiment without creative work, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A reverse osmosis pretreatment method for organic wastewater, characterized in that It includes the following steps: (1) Subject the organic wastewater to gravity sedimentation treatment to obtain primary treated wastewater; (2) Subject the primary treated wastewater to magnetic flocculation treatment to obtain secondary treated wastewater and flocculated sewage. The magnetic flocculation treatment includes sequentially adding a coagulant, a magnetic mixing agent, and a coagulant aid to the primary treated wastewater, and then performing flocculation sedimentation; (3) Subject the secondary treated wastewater to microbial electrolysis treatment to obtain carbon dioxide and tertiary treated wastewater; (4) Pass ozone into the tertiary treated wastewater and perform ozone catalytic oxidation treatment under the catalytic condition of a catalyst to degrade the organic pollutants in the tertiary treated wastewater to obtain quaternary treated wastewater.

2. The organic wastewater reverse osmosis pretreatment method according to claim 1, characterized in that, The coagulant includes polyaluminum chloride, and the mass ratio of the coagulant to the volume of the organic wastewater is (5 - 50) mg: 1 L; The magnetic mixing agent includes iron tetroxide, and the mass ratio of the magnetic mixing agent to the volume of the organic wastewater is (10 - 100) mg: 1 L; The coagulant aid includes anionic polyacrylamide and / or non-ionic polyacrylamide, and the mass ratio of the coagulant aid to the volume of the organic wastewater is (1 - 10) mg: 1 L; The pH value of the magnetic flocculation treatment is 6 - 7, and the pH value of the magnetic flocculation treatment is adjusted with carbon dioxide.

3. The organic wastewater reverse osmosis pretreatment method according to claim 1 or 2, characterized in that, After obtaining the flocculated sewage, it further includes: recovering the magnetic mixing agent from the flocculated sewage to obtain recovered magnetic mixing agent and non-magnetic substances, and recycling the recovered magnetic mixing agent to step (2).

4. The organic wastewater reverse osmosis pretreatment method according to claim 2, characterized in that, After the microbial electrolysis treatment obtains carbon dioxide, it further includes using the carbon dioxide obtained by the microbial electrolysis treatment to adjust the pH value of the magnetic flocculation treatment.

5. The organic wastewater reverse osmosis pretreatment method according to claim 1, characterized in that, The microbial electrolysis treatment is carried out under the conditions of an anaerobic anode and an oxygen-supplying cathode. The microbial electrolysis treatment is carried out in a microbial electrolysis cell. The microbial electrolysis cell includes an anode chamber and a cathode chamber, and hydrogen is also generated in the cathode chamber.

6. The organic wastewater reverse osmosis pretreatment method according to claim 1 or 5, characterized in that, The content of total organic carbon in the tertiary treated wastewater is 5 - 10 mg / L; The mass ratio of the ozone to the mass of total organic carbon in the tertiary treated wastewater is 0.5 - 1.5: 1; The catalyst is a supported catalyst, and the mass ratio of the catalyst to the ozone is 0.2 - 0.4: 1; The ozone catalytic oxidation treatment also obtains oxygen. After obtaining oxygen, it further includes using the oxygen in the microbial electrolysis treatment.

7. An organic wastewater reverse osmosis treatment method, characterized in that, It includes the following steps: Subject the quaternary treated wastewater obtained by the reverse osmosis pretreatment method of the organic wastewater according to any one of claims 1 - 6 to reverse osmosis treatment to obtain reverse osmosis pure water and reverse osmosis concentrated water.

8. The organic wastewater reverse osmosis treatment method according to claim 7, characterized in that It further includes: Using part of the reverse osmosis pure water in the microbial electrolysis treatment; The conductivity of the reverse osmosis concentrated water is ≥20000 μs / cm, and the total dissolved solids is ≥14000 mg / L; Perform energy recovery treatment on the reverse osmosis concentrated water. The energy recovery treatment is to convert the water pressure of the reverse osmosis concentrated water into electric energy.

9. An organic wastewater reverse osmosis treatment system, characterized in that, It includes a sedimentation tank, a magnetic flocculation device, a microbial electrolysis cell, an ozone treatment device, and a reverse osmosis device that are connected in sequence; The magnetic flocculation device includes a coagulation unit, a magnetic mixing unit, a coagulant aid unit, and a sedimentation unit that are connected in sequence.

10. The organic wastewater reverse osmosis treatment system according to claim 9, characterized in that, A sludge discharge plate is provided at the bottom of the sedimentation tank, and the sludge discharge plate is used to discharge the sludge in the sedimentation tank; The sedimentation unit is provided with a sewage discharge port; The microbial electrolytic cell is provided with an anodic chamber and a cathodic chamber. The anodic chamber is provided with an anode, a gas outlet and a liquid inlet. The cathodic chamber is provided with a cathode, a gas inlet, a liquid inlet and a gas outlet; The ozone treatment device is provided with an oxygen outlet, and the oxygen outlet is communicated with the gas inlet of the cathodic chamber; The reverse osmosis device is provided with a water inlet, a pure water outlet and a concentrated water outlet, and a reflux pipeline is arranged between the concentrated water outlet and the water inlet; The organic wastewater reverse osmosis treatment system further includes a magnetic powder recovery device, an energy recovery treatment device, a pure water storage tank and a hydrogen storage tank; The inlet of the magnetic powder recovery device is communicated with the sewage discharge port of the sedimentation unit; The inlet of the energy recovery treatment device is communicated with the concentrated water outlet of the reverse osmosis device; The inlet of the pure water storage tank is communicated with the pure water outlet of the reverse osmosis device; The inlet of the hydrogen storage tank is communicated with the gas outlet of the cathodic chamber.

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