A continuous advanced oxidation device and process

Abstract

The invention belongs to the field of sewage treatment, and specifically discloses a continuous advanced oxidation device and process, comprising a raw water storage tank, a loading and unloading mechanism, a catalytic oxidation zone, a flocculation zone, a sedimentation zone, a sludge scraping zone and a recycling and regeneration mechanism; the loading and unloading mechanism is used for introducing raw water and discharging clear liquid; the catalytic oxidation zone is used for catalytic oxidation of raw water; the flocculation zone is used for flocculation of catalyst; the sedimentation zone is used for precipitation of flocs; the sludge scraping zone is used for scraping off precipitated flocs; the recycling and regeneration mechanism is used for recycling and regenerating the catalyst for reuse; the invention realizes the continuous non-radical activation ability of persulfate by catalytic oxidation based on persulfate, and designs a persulfate non-radical oxidation-flocculation precipitation coupling process technology in combination with the flocculation precipitation process, which can effectively reduce the concentration of new pollutants such as endocrine disruptors and antibiotics in raw water.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a continuous advanced oxidation device and process. Background Art

[0002] At present, advanced oxidation technology has shown good removal effects for new pollutants that are difficult to degrade, such as endocrine disruptors and antibiotics in water bodies;

[0003] In advanced oxidation technology, the removal of pollutants in water bodies is generally completed by the participation of free radicals and non-free radicals. Free radicals have a short life span and a short duration of action with pollutants. They have weak anti-interference ability in the face of complex water quality conditions and are easily interfered by other substances such as suspended solids, colloids, and natural organic matter in the raw water. Therefore, the oxidation efficiency of pollutants in traditional advanced oxidation technology is affected to a certain extent, and the effective removal of new pollutants in water bodies is restricted.

[0004] In a Chinese patent with publication number CN107082473A, an advanced oxidation device and method for sewage treatment is mentioned, including a box body, an oxidation chamber is arranged in the box body, electrode plate brackets are fixedly arranged on the left and right inner walls of the oxidation chamber, and electrode plates are movably connected to the electrode plate brackets. The present invention also discloses an advanced oxidation method for sewage treatment, including the following steps: step one: installing the electrode plates on the electrode plate brackets of the oxidation chamber in sequence; step two: opening the valve on the fluid inlet pipe, and closing the valves on the fluid outlet pipe and the sewage outlet pipe at the same time; the present invention fixes the electrode plate by the electrode plate bracket, and facilitates the installation and disassembly of the electrode plate by the slot structure, so as to adjust the electrode plate spacing according to the different sewage, and the sewage passes through the electrode plate in sequence to reach one end of the fluid outlet pipe, and the sewage undergoes an oxidation-reduction reaction on the electrode plate, so as to separate the impurities in the sewage, and at the same time, the sewage outlet pipe is opened regularly to clean the precipitate separated in the oxidation chamber.

[0005] The above patent uses electrode electrolytic oxidation to treat sewage, which has high energy consumption and generates by-products that are difficult to treat during the electrolysis process. The electro-Fenton oxidation technology generated by power supply is prone to produce a large amount of iron sludge, and the pH needs to be adjusted during operation, which is not easy to use. In addition, the catalyst added in the process is a mixture of activated carbon and silica, which cannot be recycled after one use and has a high cost. Summary of the invention

[0006] The object of the present invention is to provide a continuous advanced oxidation device and process to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A continuous advanced oxidation device, including a raw water storage tank, characterized in that it includes a loading and unloading mechanism, a catalytic oxidation zone, a flocculation zone, a sedimentation zone, a sludge scraping zone and a recovery and regeneration mechanism;

[0009] The loading and unloading mechanism is used to introduce raw water and discharge clear liquid;

[0010] The catalytic oxidation zone is used for catalytic oxidation of raw water;

[0011] The flocculation zone is used for flocculation of the catalyst;

[0012] The sedimentation zone is used for sedimentation of flocs;

[0013] The scraping area includes a scraping plate arranged in the settling area for scraping off the precipitated flocs;

[0014] The recovery and regeneration mechanism is used for the recovery, regeneration and reuse of the catalyst.

[0015] Preferably, the loading and unloading mechanism includes a water pump arranged between the raw water and the catalytic oxidation zone, a supernatant discharge port arranged at the upper output end of the sedimentation zone, and a deactivated floc discharge port arranged at the lower output end of the sedimentation zone.

[0016] Preferably, the outlet of the catalytic oxidation zone is communicated with the inlet of the flocculation zone, and a stirrer is disposed inside both the catalytic oxidation zone and the flocculation zone.

[0017] Preferably, the outlet of the flocculation zone is connected to the inlet of the sedimentation zone, the flocculation zone includes a rapid stirring zone and a slow stirring zone, the liquid outlet of the rapid stirring zone is connected to the liquid inlet of the slow stirring zone, and the input end of the rapid stirring zone is connected to a flocculant storage tank through water pump 2.

[0018] Preferably, the recovery and regeneration mechanism includes a hydrocyclone arranged between the sedimentation zone and the catalytic oxidation zone, a water pump three arranged between the hydrocyclone and the sedimentation zone, a pyrolysis furnace arranged between the hydrocyclone and the catalytic oxidation zone, a drying device arranged between the hydrocyclone and the pyrolysis furnace, and a dehydration device arranged between the hydrocyclone and the drying device.

[0019] A continuous advanced oxidation process, using the above-mentioned continuous advanced oxidation device for treatment, the specific steps are as follows:

[0020] S1: adding raw water with target pollutants, nitrogen-doped sludge catalyst and persulfate oxidant into the catalytic oxidation zone and mixing them thoroughly;

[0021] S2: introducing the mixed liquid into the flocculation zone, adding flocculants to flocculate and adsorb the solid particle catalyst suspended in the water;

[0022] S3: The mixed liquid after flocculation treatment is transferred to the sedimentation area. After the flocs are precipitated and gathered at the bottom, the precipitated materials are scraped off by a scraper, and the catalyst flocs are introduced into the hydrocyclone by a water pump three;

[0023] S4: When the hydrocyclone is not working, the flocs will be directly returned to the catalytic oxidation zone together with the wastewater through the hydrocyclone to enhance the removal of pollutants in the catalytic oxidation zone; when the hydrocyclone is working, the wastewater separated by cyclone will be returned to the catalytic oxidation zone, and the catalyst flocs separated by cyclone will be transported to the dehydration device for preliminary dehydration, and then enter the drying device for drying after dehydration, and then enter the pyrolysis furnace for pyrolysis regeneration, and the regenerated catalyst will be introduced into the catalytic oxidation zone again to complete the replenishment and reuse of the catalyst;

[0024] S5: The completely purified supernatant is discharged from the sedimentation zone through the supernatant discharge port, and the deactivated catalyst flocs are discharged through the deactivated floc discharge port.

[0025] Preferably, in step S1, the dosage of the nitrogen-doped sludge catalyst is 200-500 mg / L, and the concentration of the persulfate oxidant is 0.25-2 mM.

[0026] Preferably, the flocculant in step S2 is a high molecular surfactant with a molecular weight of 8 million to 12 million, a solid content of ≥88%, a nitrogen content of ≥8%, and a dosage of 10-15 mg / L.

[0027] Preferably, the nitrogen-doped sludge catalyst regeneration step in step S4 is as follows:

[0028] S4.1. Use a hydrocyclone to transport the catalyst flocs to a dehydration device for dehydration treatment;

[0029] S4.2, drying the dehydrated catalyst flocs;

[0030] S4.3, subjecting the dried material to high-temperature pyrolysis to collect the sludge mesoporous biochar;

[0031] S4.4. The sludge mesoporous biochar is subjected to acid washing, water washing and natural drying to obtain a regenerated nitrogen-doped sludge catalyst.

[0032] Preferably, the rotation speed of the hydrocyclone in step S4.1 is 3000-5000 r / min, the drying treatment temperature in step S4.2 is 60°C-100°C, the pyrolysis temperature in step S4.3 is 700-1200°C, the heating rate is 10°C / min, and the temperature is maintained for 0.5-2h.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The present invention strengthens the 1 The generation of O2 as the main active oxygen realizes the continuous non-radical activation ability of persulfate, and combined with the flocculation precipitation process, the persulfate non-radical oxidation-flocculation precipitation coupling process technology is designed. Under complex water quality conditions, this technology can effectively reduce the concentration of new pollutants such as endocrine disruptors and antibiotics, providing new ideas for the development of advanced oxidation technology.

[0035] (2) The present invention simplifies the water treatment process by constructing a continuous flow reactor, improves the efficiency of water treatment, and saves process and manpower investment.

[0036] (3) The present invention not only effectively removes impurities such as suspended matter and colloids in water through the flocculation coupling process, but also separates the dispersed catalyst from the tail water, providing technical support for the subsequent recovery and regeneration of the catalyst.

[0037] (4) The present invention improves the utilization rate of sludge catalyst through the catalyst recovery and regeneration process, thereby saving the cost of purchasing sludge catalyst.

[0038] (5) Compared with traditional advanced oxidation processes, the present invention has lower operating costs and can avoid the generation of disinfection by-products, making it more effective in controlling pollution from new organic pollutants in water bodies.

[0039] (6) The present invention effectively removes new organic pollutants in water bodies, thereby improving water quality and contributing to reducing environmental pollution and harm to human health. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0041] Figure 2 It is a process step block diagram of the present invention;

[0042] Figure 3 It is a pollutant concentration trend diagram of the experimental example of the present invention;

[0043] Figure 4 This is a comparison diagram of the catalyst before and after regeneration of the present invention;

[0044] Figure 5 The process of the present invention strengthens the singlet 1 O2 generates the effect diagram.

[0045] In the figure: 1. Raw water storage tank; 2. Water pump 1; 3. Agitator; 4. Catalytic oxidation zone; 5. Flocculation zone; 501. Rapid stirring zone; 502. Slow stirring zone; 6. Sedimentation zone; 7. Scraping zone; 8. Scraping plate; 9. Hydrocyclone; 10. Pyrolysis furnace; 11. Supernatant discharge port; 12. Drying device; 13. Dehydration device; 14. Deactivated floc discharge port; 15. Flocculant storage tank; 16. Water pump 2; 17. Water pump 3. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] As attached Figure 1 To Attachment Figure 5 As shown:

[0048] Embodiment 1: The present invention provides a continuous advanced oxidation device, including a raw water storage tank 1, including a loading and unloading mechanism, a catalytic oxidation zone 4, a flocculation zone 5, a sedimentation zone 6, a mud scraping zone 7 and a recovery and regeneration mechanism; the loading and unloading mechanism is used for introducing raw water and discharging clear liquid; the catalytic oxidation zone 4 is used for catalytic oxidation of raw water; the flocculation zone 5 is used for flocculation of the catalyst; the sedimentation zone 6 is used for precipitation of flocs; the mud scraping zone 7 is used for scraping off the precipitated flocs; the recovery and regeneration mechanism is used for recovery, regeneration and reuse of the catalyst.

[0049] Specifically, the loading and unloading mechanism includes a water pump 2 arranged between the raw water and the catalytic oxidation zone 4, a supernatant discharge port 11 arranged at the upper output end of the sedimentation zone 6, and a deactivated floc discharge port 14 arranged at the lower output end of the sedimentation zone 6. The catalyst flocs and sludge that have completely lost their activity are discharged from the deactivated floc discharge port 14.

[0050] Specifically, the outlet of the catalytic oxidation zone 4 is connected to the inlet of the flocculation zone 5, and the inside of the catalytic oxidation zone 4 and the flocculation zone 5 are both provided with a stirrer 3. After the raw water is added into the catalytic oxidation zone 4, the nitrogen-doped sludge catalyst and the persulfate oxidant are also added into the catalytic oxidation zone 4. The nitrogen-doped sludge catalyst activates the persulfate to produce non-radical active substances. After entering the raw water, the stirrer 3 is started to make it fully mixed and reacted with the raw water, so that the new pollutants that are difficult to degrade, such as endocrine disruptors and antibiotics, in the water body can be removed;

[0051] Specifically, the outlet of the flocculation zone 5 is connected to the inlet of the sedimentation zone 6, and the flocculation zone 5 includes a rapid stirring zone 501 and a slow stirring zone 502. The liquid outlet of the rapid stirring zone 501 is connected to the liquid inlet of the slow stirring zone 502. The input end of the rapid stirring zone 501 is connected to the flocculant storage tank 15 through the water pump 16. The flocculant in the flocculant storage tank 15 is added to the rapid stirring zone 501 through the water pump 16 to flocculate and adsorb the solid particle catalyst suspended in the water. The agitator 3 is used to rapidly stir the agent and the sewage to fully mix them. The slow stirring zone 502 prevents the finally formed flocs from settling in the flocculation zone 5, so that the entire flocculation mechanism achieves the best effect.

[0052] Specifically, the recovery and regeneration mechanism includes a hydrocyclone 9 arranged between the sedimentation zone 6 and the catalytic oxidation zone 4, a water pump 17 arranged between the hydrocyclone 9 and the sedimentation zone 6, a pyrolysis furnace 10 arranged between the hydrocyclone 9 and the catalytic oxidation zone 4, a drying device 12 arranged between the hydrocyclone 9 and the pyrolysis furnace 10, and a dehydration device 13 arranged between the hydrocyclone 9 and the drying device 12.

[0053] As can be seen from the above, after the raw water, nitrogen-doped sludge catalyst and persulfate oxidant are introduced into the catalytic oxidation zone 4, they are fully mixed by the agitator 3 to generate non-radical active substances to remove pollutants in the raw water. Then, in the flocculation zone 5, the solid particle catalyst in the water is flocculated and adsorbed by the flocculant to form a larger flocculent body, which is then precipitated in the precipitation zone 6 to separate the solid and liquid. The clear liquid at the top will be discharged through the supernatant discharge port 11 to complete the water treatment work. The flocculent body precipitated to the bottom will be scraped off by the scraper 8 and then discharged by the water pump 3. 17 is transported to the catalytic oxidation zone 4 through the hydrocyclone 9 to enhance the removal of pollutants in the catalytic oxidation zone 4, or the hydrocyclone 9 is opened to transport it to the dehydration device 13 for dehydration, and then enters the drying device 12 for drying. After completion, it enters the pyrolysis furnace 10 for recovery and regeneration, and then the regenerated nitrogen-doped sludge catalyst is added to the catalytic oxidation zone 4 for oxidation treatment again to achieve continuous operation. The construction of the continuous flow reactor makes the water treatment process simpler, improves the efficiency of water treatment, and saves process and manpower investment.

[0054] Embodiment 2: This embodiment is basically the same as the previous embodiment, except that a continuous advanced oxidation process is used, and the above-mentioned continuous advanced oxidation device is used for processing. The specific steps are as follows:

[0055] S1: Add raw water with target pollutants, nitrogen-doped sludge catalyst and persulfate oxidant into catalytic oxidation zone 4 and mix them thoroughly. Persulfate has the advantages of good stability, wide pH adaptability, long half-life and high oxidation efficiency.

[0056] S2: introducing the mixed liquid into the flocculation zone 5, adding a flocculant to flocculate and adsorb the solid particle catalyst suspended in the water;

[0057] S3: the mixed solution after flocculation treatment is transferred to the sedimentation zone 6. After the flocs are precipitated and gathered at the bottom, the precipitated materials are scraped off by the scraper 8, and the catalyst flocs are introduced into the hydrocyclone 9 by the water pump 17;

[0058] S4: When the hydrocyclone 9 is not working, the flocs will be directly returned to the catalytic oxidation zone 4 together with the wastewater through the hydrocyclone 9 to enhance the removal of pollutants in the catalytic oxidation zone 4; when the hydrocyclone 9 is working, the wastewater separated by cyclone will be returned to the catalytic oxidation zone 4, and the catalyst flocs separated by cyclone will be transported to the dehydration device 13 for preliminary dehydration, and then enter the drying device 12 for drying after dehydration, and then enter the pyrolysis furnace 10 for pyrolysis regeneration, and the regenerated catalyst will be introduced into the catalytic oxidation zone 4 again to complete the replenishment and reuse of the catalyst;

[0059] S5: The completely purified supernatant is discharged from the sedimentation zone 6 through the supernatant discharge port 11 , and the deactivated catalyst flocs are discharged through the deactivated flocs discharge port 14 .

[0060] Specifically, in step S1, the dosage of the nitrogen-doped sludge catalyst is 200-500 mg / L, and the concentration of the persulfate oxidant is 0.25-2 mM.

[0061] Specifically, in step S2, the flocculant is a high molecular surfactant with a molecular weight of 8 million to 12 million, a solid content of ≥88%, a nitrogen content of ≥8%, and a dosage of 10-15 mg / L.

[0062] From the above, it can be seen that based on persulfate oxidation, the 1 The generation of O2 as the main active oxygen realizes the continuous non-radical activation ability of persulfate, and combined with the flocculation precipitation process, the persulfate non-radical oxidation-flocculation precipitation coupling process technology is designed. Under complex water quality conditions, this technology can effectively reduce the concentration of new pollutants such as endocrine disruptors and antibiotics, and provide new ideas for the development of advanced oxidation technology. The flocculation coupling process not only effectively removes impurities such as suspended matter and colloids in the water, but also separates the dispersed catalyst from the tail water, providing technical guarantee for the subsequent recovery and regeneration of the catalyst.

[0063] Embodiment 3: This embodiment is basically the same as the previous embodiment, except that the nitrogen-doped sludge catalyst regeneration step in step S4 is as follows:

[0064] S4.1. The catalyst flocs are transported to the dehydration device 13 by the hydrocyclone 9 for dehydration treatment. The dosage of the polymer surfactant is 0.2% to 0.8%, and the reflux ratio of the reflux volume to the influent volume is generally 40% to 100%;

[0065] S4.2, drying the dehydrated catalyst flocs;

[0066] S4.3, subjecting the dried material to high-temperature pyrolysis to collect the sludge mesoporous biochar;

[0067] S4.4. The sludge mesoporous biochar is subjected to acid washing, water washing and natural drying to obtain a regenerated nitrogen-doped sludge catalyst.

[0068] Specifically, in step S4.1, the rotation speed of the hydrocyclone 9 is 3000-5000 r / min, the drying treatment temperature in step S4.2 is 60°C-100°C, the pyrolysis temperature in step S4.3 is 700-1200°C, the heating rate is 10°C / min, and the temperature is maintained for 0.5-2h.

[0069] From the above, it can be seen that by dehydrating, drying and pyrolyzing the catalyst flocs for regeneration, they can be reused without significantly reducing the pollutant degradation efficiency, thereby improving the utilization rate of the sludge catalyst and saving the cost of purchasing sludge catalysts. Compared with traditional advanced oxidation processes, the operating cost is lower and the formation of disinfection by-products can be avoided. It is more effective in controlling the pollution of new organic pollutants in water bodies.

[0070] Experimental example:

[0071] The first raw water is the production wastewater of a pharmaceutical factory, which belongs to antibiotic wastewater. After testing, tetracycline hydrochloride: 14.63μg / L, roxithromycin: 14.63μg / L;

[0072] Experimental conditions: sludge catalyst dosage was 300 mg / L, persulfate concentration was 0.5 mM, hydraulic retention time was 1 h;

[0073] The second raw water is the production wastewater of a plastic production plant, which is endocrine disruptor wastewater. After testing, bisphenol A: 376.47μg / L, bisphenol S: 283.24μg / L;

[0074] Experimental conditions: sludge catalyst dosage was 400 mg / L, persulfate concentration was 1 mM, hydraulic retention time was 1.5 h;

[0075] The above-mentioned device and process and corresponding experimental conditions were used to treat two groups of wastewater respectively. The specific process is as follows:

[0076] S1: adding raw water with target pollutants, nitrogen-doped sludge catalyst and persulfate oxidant into catalytic oxidation zone 4 and mixing them thoroughly;

[0077] Results: After the wastewater was treated in catalytic oxidation zone 4, the results showed that the content of tetracycline hydrochloride in raw water 1 was 37.82μg / L, roxithromycin was 37.75μg / L, the content of bisphenol A in raw water 2 was 57.6μg / L, and the content of bisphenol S was 41.63μg / L.

[0078] S2: introducing the mixed liquid into the flocculation zone 5, adding a flocculant to flocculate and adsorb the solid particle catalyst suspended in the water;

[0079] Results: After the wastewater was treated in flocculation zone 5, the results showed that the content of tetracycline hydrochloride in raw water 1 was 1.77μg / L, roxithromycin was 2.78μg / L, the content of bisphenol A in raw water 2 was 45.3μg / L, and the content of bisphenol S was 37.82μg / L.

[0080] S3: the mixed solution after flocculation treatment is transferred to the sedimentation zone 6. After the flocs are precipitated and gathered at the bottom, the precipitated materials are scraped off by the scraper 8, and the catalyst flocs are introduced into the hydrocyclone 9 by the water pump 17;

[0081] S4: When the hydrocyclone 9 is not working, the flocs will be directly returned to the catalytic oxidation zone 4 together with the wastewater through the hydrocyclone 9 to enhance the removal of pollutants in the catalytic oxidation zone 4; when the hydrocyclone 9 is working, the wastewater separated by cyclone will be returned to the catalytic oxidation zone 4, and the catalyst flocs separated by cyclone will be transported to the dehydration device 13 for preliminary dehydration, and then enter the drying device 12 for drying after dehydration, and then enter the pyrolysis furnace 10 for pyrolysis regeneration, and the regenerated catalyst will be introduced into the catalytic oxidation zone 4 again to complete the replenishment and reuse of the catalyst;

[0082] S5: discharging the completely purified supernatant from the sedimentation zone 6 through the supernatant discharge port 11, and discharging the deactivated catalyst flocs through the deactivated floc discharge port 14;

[0083] Results: The final discharged raw water was tested, and the content of tetracycline hydrochloride in raw water 1 was 1.81μg / L, roxithromycin was 2.69μg / L, the content of bisphenol A in raw water 2 was 40.76μg / L, and bisphenol S was 37.75μg / L;

[0084]

[0085] The wastewater treatment results are shown in the table above.

[0086] The standard parts used in the present invention can all be purchased from the market, and the special-shaped parts can be customized according to the description and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0087] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0088] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0089] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0091] In the drawings of the embodiments disclosed in the present invention, only the structures involved in the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

[0092] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A continuous advanced oxidation process, comprising a raw water storage tank (1), characterized in that: It includes loading and unloading mechanisms, a catalytic oxidation zone (4), a flocculation zone (5), a sedimentation zone (6), a sludge scraping zone (7) and a recovery and regeneration mechanism; The loading and unloading mechanism is used to introduce raw water and discharge clear liquid; The catalytic oxidation zone (4) is used for catalytic oxidation of raw water; The flocculation zone (5) is used for flocculation of the catalyst; The precipitation zone (6) is used for precipitation of flocs; The scraping zone (7) comprises a scraping plate (8) arranged in the sedimentation zone (6) for scraping off the sedimented flocs; The recovery and regeneration mechanism is used for the recovery, regeneration and reuse of the catalyst; The recycling and regeneration mechanism comprises a hydrocyclone (9) disposed between the precipitation zone (6) and the catalytic oxidation zone (4), a water pump (17) disposed between the hydrocyclone (9) and the precipitation zone (6), a pyrolysis furnace (10) disposed between the hydrocyclone (9) and the catalytic oxidation zone (4), a drying device (12) disposed between the hydrocyclone (9) and the pyrolysis furnace (10), and a dehydration device (13) disposed between the hydrocyclone (9) and the drying device (12); The specific steps are as follows: S1: adding raw water with target pollutants, nitrogen-doped sludge catalyst and persulfate oxidant into the catalytic oxidation zone (4) and mixing them thoroughly; S2: introducing the mixed liquid into the flocculation zone (5), adding a flocculant to flocculate and adsorb the solid particle catalyst suspended in the water; S3: transferring the mixed liquid after flocculation treatment to the sedimentation zone (6), and after the flocs are precipitated and gathered at the bottom, using a scraper (8) to scrape off the precipitated material, and using a water pump (17) to guide the catalyst flocs into the hydrocyclone (9); S4: When the hydrocyclone (9) is not working, the flocs together with the wastewater are directly returned to the catalytic oxidation zone (4) through the hydrocyclone (9) to enhance the removal of pollutants in the catalytic oxidation zone (4); when the hydrocyclone (9) is working, the wastewater separated by cyclone is returned to the catalytic oxidation zone (4), and the catalyst flocs separated by cyclone are transported to the dehydration device (13) for preliminary dehydration, and then enter the drying device (12) for drying, and then enter the pyrolysis furnace (10) for pyrolysis regeneration, and the regenerated catalyst is introduced into the catalytic oxidation zone (4) again to complete the replenishment and reuse of the catalyst; S5: discharging the completely purified supernatant from the sedimentation zone (6) through the supernatant discharge port (11), and discharging the deactivated catalyst flocs through the deactivated floc discharge port (14); Based on persulfate oxidation, it strengthens 1 O2 is the main active oxygen, which realizes the continuous non-radical activation of persulfate. In combination with the flocculation precipitation process, a persulfate non-radical oxidation-flocculation precipitation coupling process is designed. In the step S1, the dosage of the nitrogen-doped sludge catalyst is 200-500 mg / L, and the concentration of the persulfate oxidant is 0.25-2 mM.

2. A continuous advanced oxidation process according to claim 1, characterized in that: The loading and unloading mechanism comprises a water pump (2) arranged between the raw water and the catalytic oxidation zone (4), a supernatant discharge port (11) arranged at the upper output end of the sedimentation zone (6), and a deactivated floc discharge port (14) arranged at the lower output end of the sedimentation zone (6).

3. A continuous advanced oxidation process according to claim 1, characterized in that: The outlet of the catalytic oxidation zone (4) is connected to the inlet of the flocculation zone (5), and a stirrer (3) is provided inside the catalytic oxidation zone (4) and the flocculation zone (5).

4. A continuous advanced oxidation process according to claim 1, characterized in that: The outlet of the flocculation zone (5) is connected to the inlet of the sedimentation zone (6), and the flocculation zone (5) includes a rapid stirring zone (501) and a slow stirring zone (502). The liquid outlet of the rapid stirring zone (501) is connected to the liquid inlet of the slow stirring zone (502), and the input end of the rapid stirring zone (501) is connected to a flocculant storage tank (15) via a water pump 2 (16).

5. A continuous advanced oxidation process according to claim 1, characterized in that: In the step S2, the flocculant is a high molecular surfactant with a molecular weight of 8 million to 12 million, a solid content of ≥88%, a nitrogen content of ≥8%, and a dosage of 10-15 mg / L.

6. A continuous advanced oxidation process according to claim 1, characterized in that: The nitrogen-doped sludge catalyst regeneration step in step S4 is as follows: S4.1, using a hydrocyclone (9) to transport the catalyst flocs to a dehydration device (13) for dehydration treatment; S4.2, drying the dehydrated catalyst flocs; S4.3, subjecting the dried material to high-temperature pyrolysis to collect the sludge mesoporous biochar; S4.

4. The sludge mesoporous biochar is subjected to acid washing, water washing and natural drying treatment to obtain a regenerated nitrogen-doped sludge catalyst.

7. A continuous advanced oxidation process according to claim 6, characterized in that: In step S4.1, the rotation speed of the hydrocyclone (9) is 3000-5000 r / min, the drying treatment temperature in step S4.2 is 60°C-100°C, and the pyrolysis temperature in step S4.3 is 700-1200°C, the heating rate is 10°C / min, and the temperature is maintained for 0.5-2h.

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