Wastewater organic matter low-oxygen oxidation removal device and method using reinforced electrolysis bubbles

Abstract

The application relates to a wastewater organic matter low-oxygenization removal device and method using reinforced electrolysis bubbles, which comprises an electrolytic cell, an organic matter collecting pool and a surfactant collecting pool, a diaphragm is arranged in the electrolytic cell to separate the electrolytic cell into an anode chamber and a cathode chamber, and the anode chamber and the cathode chamber are alternatively used as a wastewater treatment chamber; an anode electrode plate is arranged in the anode chamber, and a cathode electrode plate is arranged in the cathode chamber; a discharge groove is arranged on an opening side of the wastewater treatment chamber, the discharge groove is connected with a first surfactant recovery pipe leading to the surfactant collecting pool and a first discharge pipe leading to the organic matter collecting pool, and the surfactant collecting pool is connected with a surfactant feeding pipe leading to the wastewater treatment chamber. The application enables the products (charged bubbles) of electrolysis, removes organic matters in a low-oxygenization mode, and is less likely to produce organic matter byproducts due to no damage to the properties of the organic matters; meanwhile, the adhesion of the reinforced charged bubbles is more rapid and energy-saving compared with direct electrolysis oxidation of the organic matters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic wastewater treatment, and particularly relates to a device and method for removing organic matters in wastewater by using strengthened electrolysis bubbles. BACKGROUND

[0002] Electro-oxidation can quickly and effectively degrade organic pollutants in wastewater. Humic acid is an ubiquitous organic pollutant in aquatic ecological environment, and the organic load and toxicity of some high-concentration wastewater (such as landfill leachate) are mainly caused by humic acid because of its poor biodegradability. When these wastewaters are treated by electro-oxidation, the mineralization level of humic acid is affected by the quality of the treated water, especially when the water contains a hydroxyl radical scavenger; and when the degree of mineralization of the organic matter is low, toxic chlorinated organic by-products are easily formed.

[0003] In addition, the non-selective oxidation of organic matter consumes a large amount of energy in the electro-oxidation treatment process, and more energy is needed for complete mineralization. According to thermodynamic analysis, more than 80% of the power consumption comes from the oxygen evolution reaction, which is not directly related to the oxidation of organic matter. In order to improve the energy efficiency of the electro-oxidation process, current efforts are focused on developing stable electrode materials and improving the performance of electrocatalysts that can achieve rapid transfer of electrons for organic matter. However, the bubbles generated in the electrolysis process have been ignored. Bubbles are rich in energy, and buoyancy is the most intuitive manifestation of them. Some bubbles can adsorb organic matter to their surface, indicating that bubbles also have certain adhesion properties. The bubbles generated in the electrolysis process may exhibit certain electrical properties under different pH conditions, and their zeta potential is -51.8~5.5 mV. The surface charge of the bubbles can effectively enhance the adhesion of the bubbles to the organic matter, making the bubbles more stable. However, the bubbles generated in the traditional electrolysis are usually interlaced, which makes it difficult to analyze a single type of bubble. In addition, electrolysis bubbles with different surface charges are more likely to contact and merge, and the zeta potential of the bubbles will decrease with the increase of the size of the bubbles, thereby affecting the stability of the bubbles. SUMMARY

[0004] Therefore, the present application aims to provide a device and method for removing organic matters in wastewater by using strengthened electrolysis bubbles, which can control the oxidation rate of organic matter at a lower level, produce less by-products, save energy quickly, and have low investment cost.

[0005] The application adopts the following scheme: a wastewater organic matter low oxidation removal device using reinforced electrolysis bubbles, comprising an electrolytic cell, an organic matter collecting pool and a surfactant collecting pool, a diaphragm is arranged in the electrolytic cell to separate the electrolytic cell into an anode chamber and a cathode chamber, and the anode chamber and the cathode chamber are alternatively used as a wastewater treatment chamber; an anode electrode plate is arranged in the anode chamber, and a cathode electrode plate is arranged in the cathode chamber; a discharge groove is arranged on the opening side of the wastewater treatment chamber, the discharge groove is connected with a first surfactant recovery pipe leading to the surfactant collecting pool and a first discharge pipe leading to the organic matter collecting pool, and the surfactant collecting pool is connected with a surfactant feeding pipe leading to the wastewater treatment chamber.

[0006] Further, magnetic stirring rotors are arranged in the anode chamber and the cathode chamber respectively, and magnetic stirrers are arranged on the lower sides of the anode chamber and the cathode chamber respectively.

[0007] Further, an aeration head A is arranged at the bottom of the organic matter collecting pool, and an aeration head B is arranged at the bottom of the wastewater treatment chamber, and the aeration head A and the aeration head B are respectively connected with the gas outlet of a gas pump through a gas supply pipe.

[0008] Further, a slag scraper is arranged above the wastewater treatment chamber to scrape the gas float on the liquid surface in the wastewater treatment chamber to the discharge groove.

[0009] Further, a discharge port A is arranged on the side of the bottom of the wastewater treatment chamber, the discharge port A is connected with a second discharge pipe, a discharge port B is arranged on the side of the bottom of the organic matter collecting pool, the discharge port B is connected with a third discharge pipe which is in communication with the second discharge pipe, and a pressure pump and a membrane filter are arranged on the third discharge pipe.

[0010] Further, the organic matter collecting pool is connected with a second surfactant recovery pipe leading to the surfactant collecting pool, and a water pump is arranged on the surfactant feeding pipe.

[0011] Another technical solution of the present application: a wastewater humic acid low oxidation removal method, using the wastewater organic matter low oxidation removal device using enhanced electrolysis bubbles as described above, comprising the following steps: (1) the wastewater is filtered to remove suspended particles in the water body; (2) the anode chamber is selected as the wastewater treatment chamber and the cationic surfactant, the filtered wastewater is sent to the anode chamber of the electrolytic cell, the cationic surfactant is put into the anode chamber, and the anode electrode plate uses inert electrode plate; (3) the anode electrode plate and the cathode electrode plate are powered on to start running, the bubbles generated by the electrolysis of the anode chamber have excellent organic matter adhesion performance under the electrical enhancement of the surfactant, and a large amount of humic acid is carried during the rising process of the bubbles and floats on the liquid surface; (4) the scum is scraped to the discharge tank by the slag scraper and sent to the organic matter collection tank through the first discharge pipe to remove the humic acid from the wastewater; (5) after the humic acid removal work is completed, the residual cationic surfactant in the wastewater is recovered by foam fractionation method, that is, a large amount of bubbles are generated by aeration, the cationic surfactant is carried away during the rising process of the bubbles and floats on the liquid surface, and the scum is scraped to the discharge tank by the slag scraper and sent to the surfactant collection tank through the first surfactant recovery pipe; (6) the turbidity in the organic matter collection tank is further separated by standing, and the precipitated humic acid is collected after filtration.

[0012] Compared with the prior art, the present application has the following beneficial effects:

[0013] (1) The product of electrolysis (charged bubbles) is enabled in the present application to quickly remove organic matter in a low oxidation manner, and since the nature of the organic matter is not destroyed, the production of organic matter byproducts is less; at the same time, the adhesion of the enhanced charged bubbles is more rapid and energy-saving than direct electrolytic oxidation of organic matter;

[0014] (2) The present application utilizes the oxygen evolution reaction that most inert electrodes can produce during electrolysis, that is, the electrolysis of water reaction, although this reaction is not related to the direct oxidation of organic matter, but a large number of micro-electricity bubbles are produced, the use of such micro-electricity bubbles is strengthened by membrane electrolysis, so that high-efficiency organic matter removal effect can be achieved without purchasing electrodes with high oxidation potential (such as boron diamond electrodes), saving the high cost of purchasing special oxidation electrodes;

[0015] (3) The oxidation rate of organic matter in the present application is controlled at a low level, and the additive (i.e. surfactant) can be recovered at the same time as the humic acid; the recovered humic acid can be used as a soil conditioner or as a fertilizer; the recovery of the surfactant reduces the input cost of chemicals;

[0016] (4) The membrane electrolysis system of the strengthened electrolysis bubble of the application effectively utilizes the high salt electrolyte in the wastewater to meet the conductivity of electrolysis, the device is compact, which is conducive to integration and large-scale operation, and the process of recovering resources is simple and effective.

[0017] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application will be further described in detail below through specific examples and related drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The device structure schematic diagram for removing organic matter in wastewater by low oxidation of the embodiment of the present application;

[0019] Figure 2 The oxidation situation of humic acid treated by membrane electrolysis coupled cationic surfactant CTAB;

[0020] Figure 3 The recovery situation of cationic surfactant CTAB by foam fractionation method;

[0021] Figure 4 The humic acid content comparison chart;

[0022] Figure 5 The humic acid removal rate comparison chart of the first period and the second period;

[0023] Explanation of reference numerals in the drawing: 1. diaphragm; 2. anode chamber; 3. cathode chamber; 4. direct current power supply; 5. anode electrode plate; 6. cathode electrode plate; 7. magnetic stirring rotor; 8. magnetic stirrer; 9. slag remover; 10. discharge tank; 11. organic matter collection pool; 12. discharge port A; 13. air pump; 14. aeration head B; 15. surfactant collection pool; 16. aeration head A; 17. water pump; 18. discharge port B; 19. pressure pump; 20. membrane filter; 21. stop valve. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed description is exemplary and is intended to provide further description of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0025] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0026] AsFigure 1 As shown, a wastewater organic matter low oxidation removal device using reinforced electrolysis bubbles, comprising an electrolytic cell, an organic matter collection pool 11 and a surfactant collection pool 15, a diaphragm is arranged in the electrolytic cell to separate the electrolytic cell into an anode chamber 2 and a cathode chamber 3, the anode chamber 2 and the cathode chamber 3 are alternatively used as a wastewater treatment chamber, an anode electrode plate 5 is arranged in the anode chamber, a cathode electrode plate 6 is arranged in the cathode chamber, the electrode plate can be immersed in the solution, and the manufacturing form can be mesh or sheet, and the electrode distance from the diaphragm is generally 0.5-2 cm, when the anode chamber 2 or the cathode chamber 3 is used as the wastewater treatment chamber, the electrode plate in the chamber adopts a non-sacrificial electrode plate, such as an inert electrode plate; an exhaust groove 10 is arranged on the opening side of the wastewater treatment chamber, the exhaust groove 10 is connected with a first surfactant recovery pipe leading to the surfactant collection pool 15 and a first exhaust pipe leading to the organic matter collection pool, the surfactant collection pool is connected with a surfactant feeding pipe leading to the wastewater treatment chamber; compared with the traditional electrolysis system, the membrane electrolysis system adds a diaphragm to separate the gases generated by the anode and the cathode, so as to avoid the mutual collision and contact of the gases; at the same time, the pH of the two chambers is regulated, so that the electrolysis bubbles have a preliminary electric property. By adding a surfactant, the bubbles are further energized to make the bubbles have stronger electric property and adhesion. Compared with the traditional electrolysis oxidation system, the organic matter can be quickly removed by low oxidation without complete oxidation. The exhaust groove 10 is used to collect the gas float floating on the liquid surface, in the first stage, the organic matter in the wastewater is mainly carried by the gas float, at this time, the gas float is sent to the organic matter collection pool; in the second stage, the surfactant remaining in the wastewater is mainly carried by the gas float, at this time, the gas float is sent to the surfactant collection pool, so as to realize the recycling of the surfactant and save the corresponding energy consumption, and the method has universality for most electrodes with low oxidation potential.

[0027] In order to ensure the singularity of the bubble charge, a membrane electrolysis system is introduced. The membrane electrolysis system adds a diaphragm between the anode chamber and the cathode chamber, which can avoid the contact of the gases between the two chambers. In addition, it effectively reduces the neutralization of H + / OH - generated by the anode and the cathode, realizes the pH regulation of a single chamber, and the electric property of the electrolysis bubbles can be further amplified instead of affecting each other, and the bubbles are given stronger electrostatic force to carry more organic matter.

[0028] Surfactants with hydrophobic alkyl chains and hydrophilic heads are one of the most versatile organic compounds, which can be used as bubble surface modifier. Surfactants locate at the bubble surface with their hydrophobic tails pointing to the bubble interior and their hydrophilic heads pointing to the exterior. The charged groups in the hydrophilic heads can further enhance or reverse the electrical properties of the bubble. The alkyl chain hydrophobic interactions between surfactants keep the cohesion of the surfactant layer. The presence of the surfactant layer reduces the gas-liquid surface tension, thus the Laplace pressure (ΔP Laplace = 2γ / r, γ is the gas-liquid surface tension, r is the bubble radius), resulting in stable bubbles. In addition, ionic surfactants can bind charged organic matters (such as humic acid) in aquatic environments and act as a bridge connecting nanoparticles and organic matters. In particular, compared with other chemical additives, surfactants can be effectively recovered by foam fractionation.

[0029] The method of strengthening electrolytic bubbles enhances the low-oxidative removal of stubborn organic matters, saving unnecessary energy consumption caused by traditional electrolysis. At the same time, the use cost of the electrode is saved, so that the electrode with lower oxidation potential can also be used as one of the electrode materials for electro-oxidation to meet the economy of practical application.

[0030] By using the bubbles generated by the electrolysis process, and the single separation of the electrical properties of the electrolytic bubbles, and the surfactant empowerment, the electrolytic bubbles have excellent organic matter adhesion performance, and the strengthened electrolytic bubbles are relatively stable. Even when the oxidation or mineralization level of organic matter is low, it can be removed in large quantities from the water body, and the original properties of the organic matter are maintained, avoiding the production of toxic organic by-products.

[0031] The anode electrode plate 5 and the cathode electrode plate 6 are connected to the positive and negative electrodes of the direct current power supply respectively. According to the charged nature of the organic matter in the wastewater, the wastewater treatment chamber and the ionic surfactant with opposite charged nature are selected. The principle of using surfactants is that the charge of the target organic matter and the surfactant used is of opposite sign. For example, if the charged organic matter is a cationic type, anionic surfactant can be selected. The wastewater with negatively charged organic matter selects the anode chamber as the wastewater treatment chamber for treatment. The current density of the electrode plate is 1~100 mA / cm 2, the anode liquid is the wastewater, the volume of the anode liquid and the cathode liquid can be adjusted to 1:1~10:1, the cathode chamber can use KCl, K2SO4, NaCl, Na2SO4 electrolyte to directly configure the solution, and the concentration can be accepted in the range of 10~1000 mmol / L, the anode electrode plate needs to use a non-sacrificial anode plate (such as an inert electrode plate, such as titanium, ruthenium, iridium, graphite, iridium tantalum composite, ruthenium iridium composite electrode, etc.), the material of the cathode plate needs to ensure a certain conductivity material, which is not limited to inert electrode or sacrificial electrode (it can be a conventional metal sheet, such as copper, iron, aluminum, titanium plate, etc. It can also be the above-mentioned inert electrode), and the current and voltage are controlled by a direct current power supply. Conversely, the cathode chamber is selected as the wastewater treatment chamber for treatment, at this time, the cathode liquid is the wastewater, the anode liquid can be configured by K2SO4 and Na2SO4, and the cathode electrode plate needs to use a non-sacrificial anode plate (such as an inert electrode plate), and the anode plate is not limited to inert electrode or sacrificial electrode.

[0032] The wastewater organic matter low-oxidation removal device using reinforced electrolysis bubbles can be used for removal of negative organic matters (such as humic acid and fulvic acid) in wastewater, and can also be used for removal of positive organic matters (such as ammonium salt organic matter); the selected anionic surfactant can be sodium dodecyl sulfate and sodium dodecyl sulfonate, and the cationic surfactant can be hexadecyl ammonium bromide and dodecyl ammonium bromide.

[0033] In the embodiment, the diaphragm can be a commercially available pressure-driven membrane, an ion exchange membrane, or a porous material layer (such as nylon, non-woven fabric, polyester, and stainless steel mesh) stacked to form a diaphragm-like structure.

[0034] In the embodiment, the anode chamber and the cathode chamber are respectively provided with magnetic stirring rotors 7, and the lower sides of the anode chamber and the cathode chamber are respectively provided with magnetic stirrers 8; the magnetic stirring rotors 7 stir the solution to reduce the concentration polarization on both sides of the membrane, so as to avoid ion transmission difficulty in the membrane electrolysis process, and the stirring position should be avoided to overlap with the aeration position. In actual application, the stirring can also be achieved by water flow disturbance without built-in stirring.

[0035] In the embodiment, the bottom of the organic matter collection tank 11 is provided with an aeration head A16, and the bottom of the wastewater treatment chamber is provided with an aeration head B14; the aeration heads A and B are respectively connected with the air outlet of the air pump 13 through gas supply pipes; the aeration heads are provided to recycle the surfactants in the wastewater treatment chamber and the organic matter collection tank by using the foam fractionation method; the surfactants after foam fractionation are enriched in the surfactant collection tank, and the enriched surfactants can be used for the membrane electrolysis treatment in the next cycle; the air flow of the air pump is between 150 and 1000 mL / min, and the aeration time can be adjusted according to the amount of foam.

[0036] In the present embodiment, a slag scraper 9 is arranged above the wastewater treatment chamber to scrape the floated material on the surface of the liquid in the wastewater treatment chamber to the discharge groove. The floated material on the surface is collected by the slag scraper 9 to separate the organic matter or surfactant from the wastewater. The slag scraper 9 is a prior art, and its structure and principle are not specifically described here; a chain can be used to move the scraper, or a crane can be used to move the scraper; the scraper in contact with the liquid needs to be made of a safe acid-resistant material. Due to the amphiphilic nature of the surfactant, the hydrophobic end will be directed towards the air end, so a large number of bubbles formed by the surfactant can be scraped off by the slag scraper on the liquid surface.

[0037] In the present embodiment, a discharge port A12 is arranged at the bottom side of the wastewater treatment chamber, and a second discharge pipe is connected at the discharge port A, and the clarified liquid of the membrane electrolysis lower part is discharged through the discharge port A12; a discharge port B18 is arranged at the bottom side of the organic matter collection tank, and a third discharge pipe is connected at the discharge port B and communicates with the second discharge pipe, and a pressure pump 19 and a membrane filter 20 are arranged on the third discharge pipe, and the effluent of the bottom mud recovered by the membrane can be combined and discharged with the clarified liquid of the membrane electrolysis; the membrane filter 20 is used for filtering and recovering the bottom mud, and the filter membrane used can be a commercially available pressure-driven membrane, i.e. a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, a reverse osmosis membrane, etc., and the form can be a flat membrane or a hollow fiber membrane; when the flux of the filter membrane is reduced by 40%, an alkali solution is used for backwashing.

[0038] In the present embodiment, the organic matter collection tank 11 is connected with a second surfactant recovery pipe leading to the surfactant collection tank, and when the liquid level of the organic matter collection tank reaches 50%, the surfactant can also be recovered by the foam fractionation method, and the surfactant is also sent into the surfactant collection tank through the second surfactant recovery pipe, and the organic matter collection tank can also bring the floated material with the surfactant by the slag scraper. A water pump 17 is arranged on the surfactant feeding pipe.

[0039] In the present embodiment, a stop valve 21 is arranged on each of the first discharge pipe, the second discharge pipe, the third discharge pipe, the first surfactant recovery pipe, the second surfactant recovery pipe, the surfactant feeding pipe, and the air pipe.

[0040] Another technical solution of the present application: a wastewater humic acid low oxidation removal method, using the wastewater organic matter low oxidation removal device using enhanced electrolysis bubbles as described above, comprising the following steps: (1) wastewater is filtered externally (pore size up to 15 μm) to remove suspended particles in the water body; (2) select the anode chamber as the wastewater treatment chamber and the cationic surfactant, send the filtered wastewater into the anode chamber of the electrolytic cell, put the cationic surfactant into the anode chamber, the anode electrode plate uses inert electrode plate, the cathode electrode plate also uses inert electrode plate 6; (3) power on the anode electrode plate and the cathode electrode plate to start running; the final pH of the anode liquid can reach 1.7-2.5, and the final pH of the cathode liquid can reach 11.7-12.4; the bubbles generated by the anode chamber electrolysis have excellent organic matter adhesion performance under the electrical enhancement of the surfactant, and a large amount of humic acid will be carried during the rising process of the bubbles and floated on the liquid surface; (4) use the slag scraper to scrape the gas float to the discharge tank and send it into the organic matter collection pool through the first discharge pipe, to realize the removal of humic acid from wastewater; (5) after the humic acid removal work is completed (generally when the removal of humic acid reaches about 90%), the residual cationic surfactant in the wastewater is recovered by foam fractionation method, that is, a large amount of bubbles are generated by aeration, the cationic surfactant will be carried away during the rising process of the bubbles and floated on the liquid surface, and the gas float is scraped to the discharge tank by the slag scraper and sent to the surfactant collection pool through the first surfactant recovery pipe; (6) when the liquid level of the organic matter collection pool solution is 50%, the cationic surfactant in the turbid liquid is recovered by foam fractionation method; the turbid liquid in the organic matter collection pool is further separated by standing, when the bottom mud exceeds 20-30%, the precipitated humic acid is collected after filtration, and the filtered humic acid can be washed and recovered with lye.

[0041] In the present embodiment, in step (2), a sacrificial electrode such as iron or aluminum cannot be used, and the catholyte is configured with a common electrolyte such as KCl, K2SO4, NaCl, or Na2SO4, and the concentration can reach 10-1000 mmol / L. In step (3), during operation, the solutions on both sides of the membrane need to be stirred to reduce the concentration gradient on both sides of the membrane and control the occurrence of concentration polarization. In step (5), when the removal rate of the organic matter reaches about 90%, the air pump 13 is turned on, and the aeration head 14 is aerated for 10 minutes. The gas flow rate during aeration is 150-1000 mL / min. The residual surfactant rapidly reaches the liquid surface under the action of aeration, is scraped by the slag scraper 9 into the discharge tank, and then enters the surfactant collection tank 15. In step (6), when the liquid level of the organic matter collection tank solution is 50%, the air pump 13 is turned on, and the aeration head 16 connected to the organic matter collection tank is aerated. On the one hand, the residual surfactant in the organic matter collection tank is collected, and on the other hand, the liquid level is adjusted. The collected surfactant enters the surfactant collection tank 15. When the sludge in the organic matter collection tank exceeds 20-30%, the humic acid can be recovered by membrane filtration. The sludge is discharged through the organic matter collection tank discharge port B18, and under the action of the pressure pump 19, the sludge is filtered through the membrane filter 20 at a pressure of 0.2-0.8 MPa.

[0042] Under the action of membrane electrolysis, the pH on both sides of the membrane can be quickly regulated. The pH of the anode chamber is acidic, which makes the bubbles in the anode chamber of the membrane electrolysis initially positively charged and causes the humic acid to aggregate under acidic conditions. At the same time, the addition of cationic surfactant can enhance the positive charge on the surface of the bubble, further amplify the charge of the bubble, and increase the electrostatic force to adhere to the organic matter, thereby increasing the adhesion of the bubble to the humic acid. The bubbles with a large amount of humic acid adhered to them form a stable protective layer on the surface due to the hydrophobicity of the pollutants, thus exhibiting stronger stability. With the large removal of organic matter, some surfactant remains in the wastewater, which can be simply recovered by foam fractionation. There is also some surfactant on the bubbles in the organic matter collection tank that are bonded to humic acid. When the liquid level of the organic matter collection tank reaches 50%, the surfactant can also be recovered by foam fractionation. Ultimately, the organic pollutant removal effect is achieved with low energy consumption, and the added surfactant is recovered.

[0043] Since these processes do not require the destruction of organic matter and additives, the properties of the original compounds are preserved. The recovered substances can still be used. The recovered humic acid can be used as a soil conditioner or as a fertilizer. Since the oxidation of the membrane electrolysis process is relatively low, the properties of the organic matter are not changed, and the production of toxic organic by-products is avoided. Compared with traditional electrolysis, which requires large-scale oxidation or mineralization of organic matter, more energy can be saved, and the economy of the entire system is stronger through the recovery of organic matter and the reuse of additives.

[0044] Compared with traditional electro-oxidation processes, the O2 produced by anodic electrolysis water and the H2 produced by cathode are mixed with each other, and the H + and OH - are mixed with each other, causing the mutual neutralization of the surface charges on the bubbles, and the mutual attraction of electrolytic bubbles of different electricities, which easily causes the aggregation and breakage of the bubbles, thereby reducing the stability of the bubbles. The present application separates the bubbles by means of a membrane electrolysis system and a built-in diaphragm, so that the bubbles in a single chamber are relatively single, such as only oxygen exists in the anode chamber and only hydrogen exists in the cathode chamber in the process of electrolyzing water, which can avoid the mutual interlacing of bubbles of different electricities, maintain the electrification of single bubbles, and enhance the stability of the bubbles. The slightly positive electrification of the anode bubbles can preliminarily adsorb the negatively charged humic acid. At the same time, the membrane electrolysis can regulate the pH of the separated chambers, the anode continuously consumes hydroxyl ions to make the water acidic, and the cathode continuously consumes hydrogen ions in water to make the solution alkaline. The presence of the diaphragm can limit the neutralization of the acid-base ions on both sides, but also maintain a certain ion migration. Under the acidic conditions in the anode chamber of the membrane electrolysis system, the humic acid can be aggregated.

[0045] The surfactant can further strengthen or reverse the charge of the bubble. The use of cationic surfactant with positive electricity in the anode chamber of the membrane electrolysis system can strengthen the positive electrification of the bubble, and at the same time, strengthen the stability of the bubble. Since the oxygen produced by the membrane electrolysis anode initially has a certain positive electrification, the attachment of the cationic surfactant to the bubble is connected by hydrophobic force, i.e. connected by the hydrophobic alkyl chain in the gas inside the bubble. The charged head of the cationic surfactant may form repulsion with the positive charge on the bubble liquid film, so that the entire bubble has a larger contact surface area to carry humic acid. The aggregation of humic acid in the acidified state makes the bubble carry a large amount of organic matter at a time, thereby greatly improving the efficiency of humic acid removal. The organic matter adhered to the bubble can form a natural protective layer for the bubble, making it difficult for the gas inside and outside the bubble to transfer, further enhancing the stability of the bubble, and the surfactant connects the bubble and the humic acid in the form of a bridge.

[0046] The following compares the test group using the membrane electrolysis system with the control group using the traditional electrolysis system:

[0047] The test group, the diaphragm in the membrane electrolysis system was selected as an ultrafiltration membrane. The anode side of the membrane electrolysis system was connected to 250 mL of wastewater (pH = 7.1), which mainly contained 0.25 g / L humic acid and 5 g / L sodium sulfate. The cationic surfactant selected was cetyltrimethylammonium bromide (CTAB), and the concentration added was 80 mg / L. The cathode side was connected to a 2.13 g / L sodium sulfate solution. The mesh electrode plate (Ti / Pt) was completely immersed (3.5 cm x 5 cm), the electrode spacing was 2 cm, and the current density calculated according to the electrode plate area was 10.28 mA / cm 2 , and the effective membrane area was 9 cm 2 . The direct current power supply could provide two operating modes of constant current and constant voltage. The magnetic stirring intensity of the anode and cathode chambers was 500 rpm. The aeration intensity was two grades, 150 / 600 mL / min, and the aeration time was 10 min. The current of the membrane electrolysis system was 0.18 A, and the voltage was 15.5 V when it was started in the constant current mode.

[0048] The electrolysis system without adding a diaphragm was set as the control group, and the experimental conditions were completely the same as those of the membrane electrolysis system. The differences in humic acid removal efficiency between the membrane electrolysis system and the traditional electrolysis system were compared under the conditions of constant current, constant voltage, and the same energy consumption.

[0049] The test results are as follows:

[0050] Table 1 Differences in humic acid removal efficiency between the membrane electrolysis system and the traditional electrolysis system

[0051]

[0052] As shown in Table 1, regardless of the constant current / constant voltage / same energy consumption, the relative efficiency of the membrane electrolysis system (3.00) was better than that of the traditional electrolysis system (constant current: 1.64; constant voltage: 0.14; same energy consumption: 1.42). After adding the cationic surfactant CTAB, the relative efficiency of the membrane electrolysis system remained the highest (8.87) and was better than that of the traditional electrolysis system (constant current: 3.75; constant voltage: 0.82; same energy consumption: 4.17). This can be attributed to the fact that the membrane electrolysis system can adjust the pH from 7.1 to 2.23 during the electrolysis process, while the traditional electrolysis system generates H + and OH -The pH of the treated water remained between 7 and 9. The bubbles produced by the membrane electrolysis were relatively uniform, and the uniform bubbles had stronger positive charges and better stability under acidic conditions, and could adhere to more humic acid through electrostatic attraction. Meanwhile, the acidification could cause the humic acid to aggregate, so that the bubbles could carry more humic acid at one time. The humic acid adhered to the surface of the bubbles could form a natural barrier to maintain the stability of the bubbles. Therefore, the relative efficiency of the membrane electrolysis system was higher than that of the traditional electrolysis system without adding a surfactant. After adding the CTAB, the positive charge of the bubbles was strengthened, which could increase the amount of bubbles adhered and further enhance the stability of the bubbles. Therefore, the relative efficiency of the membrane electrolysis system was still the highest after adding the surfactant.

[0053] As shown in Figure 2 , during the treatment of humic acid by the membrane electrolysis coupled with the cationic surfactant CTAB, the upper liquid could be enriched with a high concentration of humic acid (963-1054%), and the content of organic matter in the lower liquid was greatly removed, only (11.7-13.7%) remained. By adding alkali, the upper and lower liquids were mixed completely, and the organic matter oxidation rate after mixing was tested to be 2.9-3.7%. It is shown that the removal of humic acid mainly relies on the enhanced adhesion of electrolytic bubbles.

[0054] As shown in Figure 3 , it is feasible to separate the cationic surfactant CTAB by the foam fractionation method, i.e. by short-term aeration. 61% of the CTAB can be recovered by aeration at an intensity of 150 mL / min for 10 min, and 80% of the CTAB can be recovered by aeration at an intensity of 600 mL / min for 10 min.

[0055] As shown in Figure 4 , after adding the surfactant to the membrane electrolysis system, 6.6% of the humic acid was complexed with the surfactant, and 7.1% remained in the lower liquid of the membrane electrolysis, and the content of the humic acid in the upper liquid of the membrane electrolysis reached 62.1%, and the residual on the electrode and the assembly reached 24.2%, and the expected recovery rate of the humic acid was between 62.1% and 86.3%.

[0056] As shown in Figure 5 , the removal rate of humic acid by the membrane electrolysis coupled with the surfactant reached 88.4% in the first cycle, and the surfactant was collected by the foam fractionation method. By short-term aeration at a flow rate of 600 mL / min for 10 min, the surfactant collected by the slag scraper could still make the removal rate of humic acid reach 88.9% in the second cycle.

[0057] Therefore, in the actual application process, the treatment method of removing humic acid by strengthening the charged bubbles can not only reduce the energy consumption, but also can efficiently recover the humic acid and the additives.

[0058] Any of the technical solutions disclosed by the present application above, if not otherwise stated, if it discloses a numerical range, the disclosed numerical range is a preferred numerical range, any person skilled in the art should understand that the preferred numerical range is only one of the many implementable values with more obvious technical effects or representative values. Because there are too many values, it is impossible to enumerate them all, so the present application discloses some values to illustrate the technical solutions of the present application, and the above enumerated values should not constitute a limitation on the protection scope of the present application.

[0059] If the present application discloses or involves mutually fixed connecting parts or structural parts, except otherwise stated, the fixed connection can be understood as: detachable fixed connection (for example, using bolt or screw connection), or as: non-detachable fixed connection (for example, riveting, welding), of course, the mutually fixed connection can also be replaced by an integral structure (for example, using casting process to integrally form and manufacture) (obviously, except for the integral forming process).

[0060] In addition, the terms used to represent the position relationship or shape in any of the technical solutions disclosed by the present application above, except otherwise stated, its meaning includes the approximate, similar or close state or shape.

[0061] Any of the components provided by the present application can be assembled from multiple individual components, or can be a single component manufactured by an integral forming process.

[0062] The above is only a preferred embodiment of the present application, and is not a limitation on other forms of the present application. Any person skilled in the art can modify or change the above disclosed technical content to obtain equivalent embodiments. However, any simple modification, equivalent change and modification made according to the technical essence of the present application without departing from the technical solution content of the present application still belongs to the protection scope of the present application.

Claims

1. A device for low-oxygen organic matter removal from wastewater using reinforced electrolysis bubbles, characterized by: The application relates to a wastewater treatment device, which comprises an electrolytic cell, an organic matter collecting pool and a surfactant collecting pool, wherein a diaphragm is arranged in the electrolytic cell to separate the electrolytic cell into an anode chamber and a cathode chamber, and the anode chamber and the cathode chamber are alternatively used as a wastewater treatment chamber; an anode electrode plate is arranged in the anode chamber, and a cathode electrode plate is arranged in the cathode chamber; a discharge groove is arranged on the wastewater treatment chamber, the discharge groove is connected with a first surfactant recovery pipe leading to the surfactant collecting pool and a first discharge pipe leading to the organic matter collecting pool, the surfactant collecting pool is connected with a surfactant feeding pipe leading to the wastewater treatment chamber; magnetic stirring rotors are arranged in the anode chamber and the cathode chamber respectively, and magnetic stirrers are arranged on the lower sides of the anode chamber and the cathode chamber respectively; an aeration head A is arranged at the bottom of the organic matter collecting pool, and an aeration head B is arranged at the bottom of the wastewater treatment chamber, and the aeration head A and the aeration head B are connected with the air outlet of a gas pump through gas supply pipes respectively.

2. The device for removing low-oxygenated organic matter from wastewater using reinforced electrolysis bubbles according to claim 1, characterized in that: A slag scraper is arranged above the wastewater treatment chamber to scrape air float on the liquid surface of the wastewater treatment chamber to the discharge groove.

3. The device for removing low-oxygenated organic matters in wastewater by using reinforced electrolysis bubbles according to claim 2, characterized in that: A discharge port A is arranged on the side of the bottom of the wastewater treatment chamber, the discharge port A is connected with a second discharge pipe, a discharge port B is arranged on the side of the bottom of the organic matter collecting pool, the discharge port B is connected with a third discharge pipe which is connected with the second discharge pipe, and a pressure pump and a membrane filter are arranged on the third discharge pipe.

4. The device for removing low-oxygenated organic matters in wastewater by using reinforced electrolysis bubbles according to claim 3, characterized in that: The organic matter collecting pool is connected with a second surfactant recovery pipe leading to the surfactant collecting pool, and a water pump is arranged on the surfactant feeding pipe.

5. A method for low-oxygen oxidation removal of humic acid in wastewater, using the device for low-oxygen oxidation removal of organic matters in wastewater by using enhanced electrolysis bubbles according to claim 4, characterized in that: The application further discloses a wastewater treatment method, which comprises the following steps: (1) removing suspended particles in water through external filtration; (2) selecting the anode chamber as the wastewater treatment chamber and a cationic surfactant, feeding the filtered wastewater into the anode chamber of the electrolytic cell, feeding the cationic surfactant into the anode chamber, and adopting an inert electrode plate as the anode electrode plate; (3) starting operation by electrifying the anode electrode plate and the cathode electrode plate, the bubbles generated by electrolysis of the anode chamber have excellent organic matter adhesion performance under the electric property enhancement of the surfactant, and a large amount of humic acid is carried by the bubbles during the rising process and floats on the liquid surface; (4) scraping the air float to the discharge groove by the slag scraper and feeding the air float into the organic matter collecting pool through the first discharge pipe, so that the humic acid is removed from the wastewater; (5) after the humic acid removal is completed, the cationic surfactant remaining in the wastewater is recovered through a foam fractionation method, that is, a large amount of bubbles are generated through aeration, the cationic surfactant is carried away by the bubbles during the rising process and floats on the liquid surface, and the air float is scraped to the discharge groove by the slag scraper and fed into the surfactant collecting pool through the first surfactant recovery pipe; and (6) further static separation of the turbid liquid in the organic matter collecting pool, and collection of the filtered humic acid.

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