CN111943408B - Device and method for removing organic pollutants in water through electro-catalytic ozone adsorption membrane filtration - Google Patents

Abstract

The invention relates to a device and a method for filtering and removing organic pollutants in water by an electrocatalytic ozone adsorption membrane, wherein the device comprises an oxygen source, an ozone generator and an ozone solution storage tank which are sequentially connected, the ozone solution storage tank and a raw water storage tank are connected with an electrocatalytic ozone membrane filtering reactor through pipelines, the electrocatalytic ozone membrane filtering reactor consists of a metal mesh electrode, a silica gel insulating washer and an electrocatalytic ozone filtering membrane electrode, wherein the positive electrode of a regulated power supply is connected with the metal mesh electrode through a connecting lead, the electrocatalytic ozone filtering membrane electrode is connected with the negative electrode of the regulated power supply through a connecting lead, and the negative electrode and the positive electrode are separated by the silica gel insulating washer. The invention has the technical advantages of low operating pressure, small applied current, low energy consumption, capability of efficiently and continuously removing the organic pollutants difficult to degrade and high efficiency of converting ozone into free radicals.

Description

A device for removing organic pollutants in water by electrocatalytic ozone adsorption membrane filtration and method

technical field

The invention relates to the technical field of water treatment, in particular to a device and method for removing organic pollutants in water.

Background technique

In recent years, with the continuous decline in the quality of drinking water sources, trace organic pollutants in the water environment, such as personal care products, pharmaceutical active substances, and natural organic matter, have gradually increased. These organic pollutants have low concentration, complex composition, stable structure, and various types, and some organic substances are considered to be the precursors of disinfection by-products. Long-term drinking of drinking water containing such pollutants has potential hazards to human health. Therefore, the targeted development of new efficient, economical and applicable drinking water treatment technology is very important to control the organic pollution in drinking water and improve the level of drinking water safety. On the other hand, the existing sewage treatment technology also cannot effectively remove trace organic pollutants in the water, and the discharge of untreated sewage into the water environment will cause ecological environmental pollution or affect water recycling. Therefore, it is very important to develop an efficient, safe and environmentally friendly water treatment technology suitable for both advanced wastewater treatment and wastewater reuse.

Traditional membrane filtration technologies such as ultrafiltration and microfiltration membranes cannot effectively remove trace organic pollutants in water, while nanofiltration and reverse osmosis membranes are unstable in removing such organic pollutants, and the operating pressure is high and the operating cost is high. The nanomaterial low-pressure composite membrane filtration technology developed on this basis can effectively balance the relationship between selectivity and water permeability by changing the physical and chemical properties of the traditional membrane surface and enhancing the adsorption performance of the material. It is effective for most organic pollutants. Excellent removal effect. However, there are regeneration problems and membrane fouling problems in the long-term use of composite membranes, which limit the further development and application of this technology. The electrochemical membrane filtration technology developed based on this can deeply degrade and remove a variety of organic pollutants, has strong environmental compatibility, and alleviates the problem of membrane fouling to a certain extent. However, this technology is also affected by various factors such as electrochemical oxidation efficiency, low electron utilization, and electrolytic current, and it is not easy to control the final process of the reaction.

As a commonly used advanced oxidation technology, ozone has good disinfection, decolorization, and oxidation capabilities. There are two ways to play an oxidation role in water treatment: direct ozone oxidation is selective, and the mineralization efficiency is low, and it will also produce disinfection. By-product precursors; in the advanced oxidation technology based on OH, the reaction between OH and organic matter is non-selective, and the reaction rate constant is much larger. The removal of pollutants by ozone advanced oxidation is mainly direct oxidation, while the indirect oxidation of ozone generally occurs in the combination technology of ozone and other processes, such as the combination of ozone and H ₂ O ₂ , UV and other technologies.

E-peroxone technology is a new electrochemical technology developed on the basis of ozone oxidation. This technology uses the characteristics of carbon-based electrodes to electrocatalytically reduce oxygen to produce H ₂ O ₂ , and combines it with ozone oxidation to enhance the generation of OH. Electrocatalytic ozonation technology has a good removal effect on refractory organic pollutants, but the solubility of ozone and oxygen in water is small; and ozone is unstable in the environment, and it is easy to decompose to generate oxygen; moreover, the ozone produced by the current ozone generator The mass concentration (gas phase partial pressure) is relatively low, and the mass transfer and conversion efficiency of ozone in water is low. Therefore, how to enhance the gas-liquid mass transfer efficiency of ozone and oxygen and improve the gas utilization rate is a key and prerequisite for the research and application of ozone catalytic oxidation technology. CN 107200394 A discloses an electrocatalytic ozone advanced oxidation membrane reactor wastewater treatment device and method, including an adjustable DC voltage stabilized power supply, connecting wires, a hydrophobic membrane (conductive hydrophobic membrane) loaded with a conductive layer, an auxiliary electrode, and a feed solution Tanks, peristaltic pumps, ozone generators, gas flow meters and other parts, this method can efficiently treat refractory organic wastewater such as dyes, petrochemicals, pharmaceuticals and other industries, as well as trace organic matter in the effluent of sewage plants. The electrocatalytic ozone membrane reactor proposed in the above-mentioned patent uses the hydrophobic membrane as a distributor of oxygen and ozone gas, which can only improve the dissolution and diffusion of ozone gas and the generation of free radicals to a certain extent. However, due to the short lifetime and slow diffusion speed of free radicals (such as hydroxyl radicals, superoxide radicals, peroxyl radicals, etc.), it is necessary to further strengthen the diffusion and mass transfer between pollutants and free radicals to improve ozone catalytic oxidation. The degradation efficiency of medium pollutants. In addition, this type of electrocatalytic ozone membrane reactor relies solely on the free radicals generated by the action of E-peroxone to treat water pollutants, and does not involve the synergistic effects of adsorption, electrochemical filtration, and convective mixing of pollutants and free radicals.

The carbon material has excellent electrical conductivity and adsorption properties, and the electrode prepared by the carbon material has a good electrocatalytic reduction of oxygen to generate hydrogen peroxide (H ₂ O ₂ ). In recent years, a large number of researches and applications have used carbon materials for the removal of organic pollutants in water, and significant progress has been made. This type of research mainly uses the large specific surface area of carbon materials to adsorb and remove pollutants, or use them in the preparation of electrodes to build electrochemical advanced oxidation systems to degrade pollutants. CN104211138A discloses a method for preparing a membrane electrode based on carbon nanotubes and electrolytically removing organic pollutants. The method combines membrane filtration and electrocatalytic degradation technology to catalytically degrade organic pollutants flowing through membrane pores while adsorbing and filtering. However, adsorption removal of pollutants cannot be completely removed, and there are problems such as adsorption saturation, regeneration, and solid waste treatment and disposal; while free radicals produced by electrocatalysis (such as: hydroxyl radicals, superoxide radicals, peroxide Free radicals, etc.) have short lifetimes and slow diffusion rates, so the diffusion and mass transfer between pollutants and free radicals has become the most critical factor limiting the degradation efficiency of pollutants in the advanced oxidation process.

Contents of the invention

The purpose of the present invention is to overcome the technical deficiencies of adsorption saturation in adsorption filtration, low efficiency of electrochemical oxidation degradation, low efficiency of electrocatalytic ozonation to transform hydroxyl radicals, and low utilization rate of ozone. Provides a high-throughput electrocatalytic ozone adsorption membrane filtration device and method for removing organic pollutants in water, which couples adsorption membrane filtration, electrocatalysis and ozone oxidation, uses filtration to enhance mass transfer, improves current utilization and solves traditional high-level problems The low concentration of pollutants in the interface reaction of oxidation limits the degradation rate; the preparation and screening of H ₂ O ₂ with high electrocatalytic reduction in situ generation efficiency, high flux, high conductivity, anti-oxidation properties and stability Carbon nanomaterial composite membrane, electrocatalytically reduces oxygen to generate H ₂ O ₂ and reacts with ozone in the influent to generate hydroxyl radicals. By strengthening the generation of hydroxyl radicals and diffusion and mass transfer, the efficient removal of refractory organic pollutants in water is achieved. , Rapid and continuous removal.

The invention provides a device for removing organic pollutants in water by electrocatalytic ozone adsorption membrane filtration, which includes an oxygen source, an ozone generator and an ozone solution storage tank connected in sequence, and the ozone solution storage tank and the raw water storage tank are connected by a pipeline and an electric The catalytic ozone membrane filter reactor is connected. The electrocatalytic ozone membrane filter reactor is composed of a metal mesh electrode, a silica gel insulating gasket, and an electrocatalytic ozone filter membrane electrode. The catalytic ozone filter membrane electrode is connected with the negative pole of the stabilized voltage power supply through a connecting wire, and the cathode and anode are separated by a silicone insulating gasket.

Further, a layer of conductive carbon material is loaded on the surface of the electrocatalytic ozone filter membrane electrode, which has good electrical conductivity and good chemical stability, and can resist ozone and free radical oxidation; and can be oriented under electrochemical action A two-electron reduction reaction occurs, reducing oxygen to hydrogen peroxide. The feed water permeates the filter membrane electrode under a certain pressure, and the trace organic pollutants contained in it are adsorbed on the surface of the conductive nano-layer and in the pores of the material for enrichment. At the same time, the membrane electrode reduces the oxygen in the aqueous solution under the cathodic electrocatalysis to generate hydrogen peroxide, which further reacts with the ozone flowing into the channel to generate a large number of free radicals, and finally degrades and removes the pollutants enriched in the channel.

Further, the electrocatalytic ozone filter membrane electrode is a composite membrane electrode of carbon-containing materials, and the carbon materials include carbon nanotubes, carbon nanofibers, carbon felt, carbon paper and carbon black; the loading capacity of the conductive nanomaterials is 5-500g /m ² , the thickness of the conductive layer is between 5 μm-1 mm; optionally, the surface of the carbon nanomaterial contains one or more functional groups among hydroxyl, carboxyl, and amino groups.

Further, the electrocatalytic ozone filter membrane electrode is composed of a carbon material conductive layer and a base film, and its preparation method is to first configure a uniformly dispersed carbon material dispersion, and then load it on a vacuum filter or pressure filter. The surface of the basement membrane; or made by pressing carbon fiber cloth or carbon paper on the surface of the basement membrane.

Further, the ozone generator is connected with the ozone solution storage tank through the gas flow valve and the gas flow meter, and connected with the electrocatalytic ozone membrane filter reactor through the filter pump or the dosing pump; the raw water storage tank is connected with the filter pump or the dosing pump The pump is connected with the electrocatalytic ozone membrane filter reactor.

As another object of the present invention, the present invention provides a method for utilizing the above-mentioned device to remove organic pollutants in water, comprising the steps of:

(1) Turn on the oxygen source, start the ozone generator, pass the mixed gas of ozone and oxygen into the ozone solution storage tank, control the gas flow rate between 0.1-10L min ^-1 , and control the ventilation time between 15-60min During the period, the concentration of dissolved ozone in the influent water is controlled between 0.5-40mg L ^-1 ;

(2) Pump the liquid in the ozone solution storage tank and the liquid in the raw water storage tank to the electrocatalytic ozone membrane filter reactor according to the ratio. The ratio of the incoming water is controlled between 1:1-100:1. The ratio of water ozone solution concentration to hydrogen peroxide output is controlled at 1:1-3:1;

(3) Start the electrocatalytic ozone membrane filtration reactor, and control the membrane filtration flux between 50–150L m ^-2 h ^-1 ; the current between 0.1-5A, and the voltage between 1-10V.

Further, the raw water to be treated also contains electrolytes, the electrolyte is mainly sodium sulfate or sodium chloride, the concentration is 0.1-600mM, and the pH of the raw water to be treated is 4-10.

Further, the organic pollutants include rhodamine B and ibuprofen.

Beneficial effects of the present invention: the present invention couples adsorption membrane filtration, electrochemical redox and ozone oxidation, and fundamentally solves the problems of adsorption saturation and regeneration in adsorption membrane filtration; the effect of electrochemical advanced oxidation is poor, and the The problem that most refractory organic pollutants can hardly be degraded; the problem of low reaction rate caused by diffusion and mass transfer limitation of advanced oxidation; and the problem of selective oxidation of ozone and low utilization rate. Through the filtration flow field, the diffusion and mass transfer of pollutants and electrons on the surface and inside of the electrode can be enhanced, the utilization rate of electrons and reaction efficiency can be improved, and the reaction residence time can be controlled within 5s-1min; Catalytic reduction of oxygen in situ generates H ₂ O ₂ , which reacts with ozone in the feed water to further strengthen the generation of hydroxyl radicals; residual trace organic pollutants are adsorbed on the electrode surface and Enrichment in the micropores, and further oxidative degradation; the final synergistic effect to achieve continuous and efficient removal of organic pollutants.

The invention improves the effect of filtering and removing refractory organic pollutants in water. While promoting the catalytic degradation process of pollutants at the membrane interface, the mass transfer between the solid-liquid interface is strengthened; a new water treatment technology integrating filtration-adsorption-degradation is constructed, and the pollutant removal rate is improved by exerting a synergistic mechanism. At the same time, a good removal effect was obtained. After continuous operation for 40 hours, the removal rate was stable at 99.87% when the concentration of Rhodamine B in the influent was 10 mg L ^-1 ; when the concentration of ibuprofen in the influent was 1 mg L ^-1 , the removal rate reached 99.5%.

Description of drawings

Fig. 1 is the structural representation of device of the present invention;

Figure 2 is a schematic diagram of the electrocatalytic ozone adsorption and degradation membrane filtration reactor reaction

Fig. 3 is the line chart of the efficiency of removing organic pollutant rhodamine B in water by the present invention;

Fig. 4 is the line graph of the efficiency of removing organic pollutant rhodamine B in water under different influent electrolyte conditions of the present invention;

Fig. 5 is the line graph of the efficiency of removing organic pollutant rhodamine B in water under different influent pH conditions of the present invention;

Fig. 6 is the efficiency line chart that the present invention removes the organic pollutant ibuprofen in drinking water;

Fig. 7 is the line chart of the efficiency of removing organic pollutant ibuprofen in drinking water by different filtration systems of the present invention;

In the accompanying drawings, the list of components represented by each label is as follows: 1. Oxygen source, 2. Ozone generator, 3. Gas flow valve, 4. Gas flow meter, 5. Raw water storage tank, 6. Dosing pump, 7. Ozone solution storage tank, 8. Electrocatalytic ozonation membrane filter reactor, 9. DC stabilized power supply.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, an electrocatalytic ozone adsorption membrane filter removes organic pollutants in water, including an oxygen source 1, an ozone generator 2, a gas flow valve 3, a gas flow meter 4, an ozone solution storage tank 5, and a raw water storage tank. Tank 7, dosing pump 6 (or filter pump), electrocatalytic ozonation membrane filter reactor 8, DC stabilized power supply 9, connecting wires, metal mesh electrodes, silicone insulating gaskets, nanomaterial conductive filter membrane electrodes and other parts.

Oxygen source 1 (generator or gas cylinder) is connected to ozone generator 2 to provide ozone gas source, and ozone generator 2 is connected to raw water storage tank 7 through an oxidation-resistant airflow pipeline, and the mixed gas of ozone and oxygen produced by ozone generator 2 Pass into the ozone solution storage tank 5; the ozone solution and the original aqueous solution are injected into the electrocatalytic ozone membrane filter reactor 8 with a certain pressure through the dosing pump 6 respectively; The DC power supply 9 is connected to provide current. The electrocatalytic ozone membrane filter reactor 8 is composed of a metal mesh electrode, a silica gel insulating gasket, and an electrocatalytic ozone filter membrane electrode. The negative poles of the stabilized power supply 9 are connected by connecting wires, and the anode and cathode are separated by insulating gaskets of silica gel.

As a preferred embodiment, the cathode in the electrocatalytic ozone membrane filtration reactor is a hydrophilic conductive filter membrane electrode, the auxiliary metal mesh electrode is an anode, and the original aqueous solution is filtered as an electrolyte to form an electrolysis device.

As a preferred embodiment, the electrocatalytic ozone membrane filtration reactor is a continuous flow filter, and the influent solution and the ozone solution flow into the reactor at a constant flow rate, and are successively filtered through the anode and the cathode, wherein the oxygen is reduced at the cathode Hydrogen peroxide (H ₂ O ₂ ) is generated, and the resulting hydrogen peroxide reacts with ozone (O ₃ ) in the influent to generate strong oxidizing free radicals, which oxidize and degrade pollutants.

As a preferred embodiment, the surface of the electrocatalytic ozone filter membrane electrode is loaded with a layer of conductive nanomaterials, and the influent water flows through the surface of the filter membrane electrode, and the organic pollutants contained therein are adsorbed on the surface of the conductive nanolayer, and are then combined with the electrocatalytic ozone to generate The strong oxidizing free radicals in the filter undergo an oxidation reaction and are eventually degraded, and the continuous reaction of the above-mentioned adsorption and degradation is continuously cycled during the filtration process, so as to realize the long-term continuous and efficient removal of organic pollutants in water.

As a preferred embodiment, the reactor feed water is continuously pumped into the filter through the filter pump, and the membrane filtration flux is between 50-150L m ^-2 h ^-1 ; in order to build an electrocatalytic ozone reaction system, a DC stabilized voltage is added The power supply is respectively connected with the anode of the metal mesh and the cathode of the conductive material filter membrane, the current is between 0-5A, and the voltage is between 1-10V.

As a preferred embodiment, the electrocatalytic ozone membrane filter cathode is a carbon material composite membrane electrode, which is mainly made of highly conductive carbon nanomaterials, which can be prepared by combining, conducting polymers, metals or metal oxides; the surface of the carbon material Optionally contain one or more functional groups of hydroxyl group, carboxyl group, amino group; the main components of other carbon materials such as carbon nanotubes, carbon fibers, carbon fiber cloth, carbon felt, carbon paper, carbon black, etc.

As a preferred embodiment, the carbon nanotube electrocatalytic ozone filter membrane electrode is composed of a carbon nanomaterial tube conductive layer and a base film, and its preparation method is to first configure and prepare a uniformly dispersed carbon nanotube dispersion solution, and then vacuum filter Or it can be loaded on the surface of the basement membrane by means of pressure filtration; or it can be made by pressing carbon fiber cloth or carbon paper on the surface of the basement membrane.

As a preferred embodiment, the loading amount of the conductive nano material is 5-500 g/m ² , and the thickness of the conductive layer is between 5 μm-1 mm.

Example 1

In this embodiment, the electrocatalytic ozone filter membrane electrode is pressed by commercial carbon cloth (conductive layer) and support layer (hydrophilic filter membrane), and is connected to an external power supply. The organic pollutants in the influent are first adsorbed on the carbon cloth layer, and at the same time, the filter membrane electrode electrocatalyzes the reduction of oxygen to generate H ₂ O ₂ in situ, which reacts with the ozone in the influent to generate strong oxidative free radicals, and then reacts with ozone to generate strong oxidative free radicals. The base undergoes an oxidation reaction and is eventually degraded, and the above-mentioned continuous reaction of adsorption and degradation is continuously cycled during the filtration process, thereby realizing long-term continuous and efficient removal of organic pollutants in water.

The electrocatalytic ozone membrane filtration reactor is characterized in that its operation is as follows: the reactor feed water is continuously poured into the filter through the filter pump, and the membrane filtration flux is 140L m ^-2 h ^-1 ; in order to construct the electrocatalytic ozone reaction system, additional The DC stabilized power supply is respectively connected with the metal mesh anode and the carbon material filter membrane cathode, and the voltage is at 2.5V.

The electrocatalytic ozone membrane filtration system is applied to the removal of organic pollutants in wastewater. The concentration of organic pollutant Rhodamine B (RhB) in the influent solution is 10 mg L ^-1 , and the concentration of electrolyte sodium sulfate (Na ₂ SO ₄ ) is 10mM, the influent pH is 7, the continuous filtration time is 40h, and the applied voltage is 2.5V. See Figure 3 and Table 1 for the experimental results.

Example 2

Except that the electrocatalytic ozone filter membrane electrodes are made of carbon nanotubes and hydrophilic membranes, the other device configurations are the same as in Example 1. The carbon nanotube electrocatalytic ozone filter membrane electrode is composed of a carbon nanotube material tube conductive layer and a base film. Its preparation method is to prepare a uniformly dispersed carbon nanotube dispersion solution first, and then vacuum filter or pressurize it. Loaded on the basement membrane surface. The loading capacity of the conductive nanomaterial was 22g/m ² , and the thickness of the conductive layer was 85 μm. See Figure 3 and Table 1 for the experimental results.

Example 3

Except that the rhodamine B (RhB) concentration in the raw water stock solution was 10 mg L ^-1 , and the filtration time was 120 min, the rest of the equipment and experimental parameters were the same as those in Example 1. See Figure 4 and Table 1 for the experimental results.

Example 4

Except that the electrolyte sodium chloride (NaCl) concentration in the raw water stock solution is 10 mM, other devices and experimental parameters are the same as in Example 3. See Figure 4 and Table 1 for the experimental results.

Example 5

Except that the concentration of the electrolyte sodium chloride (NaCl) in the raw water stock solution is 1 mM, other devices and experimental parameters are the same as in Example 3. See Figure 4 and Table 1 for the experimental results.

Example 6

Except that the electrolyte sodium chloride (NaCl) concentration in the raw water stock solution is 0.1 mM, other devices and experimental parameters are the same as in Example 3. See Figure 5 and Table 1 for the experimental results.

Example 7

Except that the electrolyte sodium chloride (NaCl) concentration in the raw water stock solution is 10 mM, and the pH is 6, the rest of the equipment and experimental parameters are the same as in Example 3. See Figure 5 and Table 1 for the experimental results.

Example 8

Except that the concentration of electrolyte sodium chloride (NaCl) in the raw water stock solution is 10 mM and the pH is 8, the rest of the equipment and experimental parameters are the same as in Example 3. See Figure 5 and Table 1 for the experimental results.

Example 9

Except that the concentration of organic pollutant ibuprofen (IBU) in the raw water stock solution was 1 mgL ^-1 , and the concentration of electrolyte sodium chloride (NaCl) was 10 mM, the rest of the device configuration was the same as that of Example 3. See Figure 6 and Table 1 for the experimental results.

Ibuprofen is a common trace personal care drug pollutant in drinking water, and the environmental concentration is usually in nanograms per liter to milligrams per liter, and ibuprofen is an ozone-resistant pollutant, and the reaction rate constant with ozone is It is k _O3 =9.6M ^-1 s ^-1 , and the reaction rate constant with hydroxyl radical is k _OH =7.4×10 ⁹ M ^-1 s ^-1 . Therefore, choosing ibuprofen as the target pollutant can better evaluate the removal effect of this technology on refractory organic pollutants.

Example 10

Except that 1mgL ^-1 ibuprofen (IBU) was selected as the organic pollutant in the raw water storage tank, and the electrolyte sodium chloride (NaCl) was 10mM, the rest of the device had the same configuration as in Example 2. The experimental results are shown in Figure 6 and Table 1.

Comparative example 1

Except that the ozone generator was turned off and the external power supply was turned off in the experiment, the rest of the filtering device was the same as in Example 10, and the experimental results are shown in Figure 7 and Table 1.

Comparative example 2

Except that the ozone generator was turned off in the experiment, the other filtering devices were the same as in Example 10, and the experimental results are shown in Fig. 7 and Table 1.

Comparative example 3

Except that the external power supply was turned off during the experiment, the rest of the filtering device was the same as that of Example 10. See Figure 7 and Table 1 for the experimental results.

Comparative example 4

A device for removing organic pollutants in drinking water by Peroxone membrane filtration. In addition to adding 10mgL ^-1 hydrogen peroxide (the same amount of hydrogen peroxide generated in situ by electrocatalytic reduction of oxygen) to the raw water solution, the external power supply is turned off, and the rest of the filter device Same as Example 10, see Figure 7 and Table 1 for the experimental results.

Table 1 The operating conditions and removal efficiency of different filtration systems to remove organic pollutants in water

Comparative analysis of the above examples and comparative examples shows that the present invention has a good continuous and efficient removal effect of refractory organic pollutants. The system can still maintain a stable removal effect after 40 hours of continuous operation, and the removal rate of Rhodamine B can reach up to 99.87%. The adsorption capacity of the membrane gradually reached saturation, and finally the ibuprofen could hardly be removed after 120min continuous filtration; while the electrochemical filtration could only remove 15.42%, and pure electrochemical oxidation was difficult to degrade most of the organic pollutants. The lower pseudo-first-order kinetic constant (0.07×10 ^-3 s ^-1 ) of chemical degradation of ibuprofen is consistent with that; the ozone oxidation is selective, and ibuprofen as an anti-ozonation pollutant is difficult to be decomposed by ozone Direct oxidative degradation, so ozone membrane filtration can only remove 14.61% of ibuprofen through ozone indirect oxidation; Peroxone membrane filtration removes 38.29%, and peroxone reaction conditions are constructed by directly adding H ₂ O ₂ to the influent, on the one hand peroxidation The amount of hydrogen is not easy to control. On the other hand, excessive hydrogen peroxide will consume the generated hydroxyl radicals, which will eventually affect the degradation effect of ibuprofen; while the removal rate of the present invention is stable at 99.5% during the whole filtration process. In summary, the present invention constructs an organic matter removal system integrating membrane filtration, adsorption, electrocatalysis, ozonation, and Peroxone, and shows a good and stable removal effect in the removal process of refractory organic pollutants.

The above-mentioned embodiments only express the implementation manner of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (2)

1. A method for removing organic pollutants in water is characterized in that an adopted device comprises an oxygen source, an ozone generator and an ozone solution storage tank which are sequentially connected, wherein the ozone solution storage tank and a raw water storage tank are connected with an electro-catalytic ozone membrane filtration reactor through pipelines, the electro-catalytic ozone membrane filtration reactor is composed of a metal mesh electrode, a silica gel insulating washer and an electro-catalytic ozone filtration membrane electrode, wherein the positive electrode of a stabilized voltage power supply is connected with the metal mesh electrode through a connecting lead, the electro-catalytic ozone filtration membrane electrode is connected with the negative electrode of the stabilized voltage power supply through a connecting lead, and the negative electrode and the positive electrode are separated by the silica gel insulating washer;

the surface of the electro-catalytic ozone filter membrane electrode is loaded with a layer of conductive nano material, inlet water flows through the surface of the filter membrane electrode, organic pollutants contained in the inlet water are adsorbed on the surface of the conductive nano material, and then the organic pollutants and free radicals generated by electro-catalysis of ozone entering membrane holes are subjected to oxidation reaction and finally degraded; the conductive nanomaterial supportThe amount is 5-500g/m ² The thickness of the conductive layer is between 5 mu m and 1 mm;

the electrocatalytic ozone filter membrane electrode is a carbon material composite membrane electrode, the carbon material is a carbon nano tube, and the surface of the carbon material contains one or more functional groups of hydroxyl, carboxyl and amino;

the organic pollutants are rhodamine B and ibuprofen;

the method comprises the following steps:

(1) Opening oxygen source, starting ozone generator, introducing the generated mixed gas of ozone and oxygen into ozone solution storage tank, and controlling gas flow at 0.1-10L min ^-1 The aeration time is controlled between 15 min and 60min, and the concentration of dissolved ozone in the inlet water is controlled between 0.5 mg L and 40mg L ^-1 To (c) to (d);

(2) The liquid in the ozone solution storage tank and the liquid in the raw water storage tank are pumped into the electro-catalytic ozone membrane filtration reactor according to the proportion, the water inlet proportion is controlled to be 1:1-100, and the proportion is adjusted to control the proportion of the concentration of the ozone solution in the water inlet to the yield of the hydrogen peroxide to be 1:1-3:1.

(3) Starting the electro-catalytic ozone membrane filtration reactor, and controlling the membrane filtration flux to be 50-150L m ^-2 h ^-1 To (c) to (d); the voltage is between 1 and 10V;

the electrocatalysis ozone filtering membrane electrode consists of a carbon nano material conducting layer and a basement membrane, and the preparation method comprises the steps of firstly preparing uniformly dispersed carbon nano tube dispersion liquid, and then loading the carbon nano tube dispersion liquid on the surface of the basement membrane in a vacuum filtration or pressure filtration mode; or carbon fiber cloth or carbon paper is pressed on the surface of the basement membrane to be manufactured;

the raw water to be treated also contains electrolyte, the electrolyte is sodium sulfate or sodium chloride, the concentration is 0.1-600mM, and the pH of the raw water to be treated is 4-10.

2. The method of claim 1, wherein the ozone generator is connected to the ozone solution storage tank through a gas flow valve and a gas flow meter, and is connected to the electro-catalytic ozone membrane filtration reactor through a filtration pump or a dosing pump; the raw water storage tank is connected with the electro-catalytic ozone membrane filtration reactor through a filter pump or a dosing pump.

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