Treatment system for phase change material production wastewater

Abstract

The utility model relates to the technical field of wastewater treatment, in particular to a phase change material production wastewater treatment system which comprises a pretreatment system, a biological treatment system and a sludge dewatering system, the pretreatment system comprises catalytic oxidation equipment and a denitrification reactor, the catalytic oxidation equipment is used for promoting long-chain organic matters in the wastewater to be subjected to ring-opening and chain-scission reactions, and the denitrification reactor is used for reacting with ammonia nitrogen in the wastewater. According to the characteristics of pollutants in wastewater, a process of'precision filtration, catalytic oxidation and nitrogen removal 'is adopted for pretreatment, so that on one hand, the concentration of organic pollutants in the wastewater is reduced and the organic pollutants are converted into short-chain low-molecular organic matters, and further treatment of a subsequent biological treatment system is facilitated; in addition, by adopting the denitrification reactor for pre-denitrification, the treatment load of a subsequent system can be reduced; in the biological treatment stage, a combined process of a membrane bioreactor, a short-cut nitrification reactor and an anaerobic ammonia oxidation reactor is adopted for treatment, and finally up-to-standard discharge is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a treatment system for wastewater produced by phase change materials. Background Art

[0002] Phase change materials or latent heat storage materials are materials that utilize the phase change of the material itself to passively absorb or release a large amount of heat from the surrounding environment, thereby achieving the purpose of thermal management. Phase change materials are widely used in the fields of optics, electronic information, cosmetics, biomedicine, and chemical analysis. Phase change materials mainly use high molecular organic matter, alkane organic matter, and other functional materials in the production process. Therefore, the concentration of organic pollutants and ammonia nitrogen in production wastewater is high and difficult to biodegrade, making wastewater treatment difficult.

[0003] For wastewater with high content of refractory organic matter and high content of ammonia nitrogen, the "pretreatment + full nitrification and denitrification biological treatment" process is usually used for treatment. This process route has the problems of high operating costs and low efficiency in removing organic matter and ammonia nitrogen. How to improve the efficiency of pretreatment, reduce the load entering the biological treatment system while reducing energy consumption, and improve the efficiency of organic matter and ammonia nitrogen treatment is the problem that this application aims to solve. Utility Model Content

[0004] Aiming at the technical problems existing in the treatment of organic wastewater in the prior art, the utility model proposes a treatment system for phase change material production wastewater, including a pretreatment system, a biological treatment system and a sludge dewatering system;

[0005] The pretreatment system includes a catalytic oxidation device and a denitrification reactor. The catalytic oxidation device is used to cause the long-chain organic matter in the wastewater to undergo ring opening and chain breaking reactions to generate small-molecule organic matter. The denitrification reactor is used to react with ammonia nitrogen in the wastewater to reduce the ammonia nitrogen concentration in the wastewater.

[0006] The biological treatment system comprises a membrane bioreactor, a short-cut nitrification reactor and an anaerobic ammonium oxidation reactor, and the wastewater is treated by passing through the membrane bioreactor, the short-cut nitrification reactor and the anaerobic ammonium oxidation reactor in sequence;

[0007] Sludge dewatering system;

[0008] Wherein, an intermediate water tank is provided before the membrane bioreactor, the discharge end of the denitrification reactor is connected to the intermediate water tank, the sludge produced in the membrane bioreactor is discharged into the sludge dewatering system, and the filtrate produced by the sludge dewatering system flows back to the intermediate water tank.

[0009] Preferably, an aeration device is provided in the membrane bioreactor, and the aeration device is configured to make the dissolved oxygen of the wastewater in the membrane bioreactor be 2-4 mg / L.

[0010] Preferably, an aeration device is provided in the short-cut nitrification reactor, and the aeration device is configured to make the dissolved oxygen of the wastewater in the short-cut nitrification reactor be 0.5-1.0 mg / L.

[0011] Preferably, the anaerobic ammonium oxidation reactor is provided with a carbon source dosing system for cultivating anaerobic ammonium oxidation bacteria so that nitrite entering the anaerobic ammonium oxidation reactor reacts with ammonia nitrogen to generate nitrogen gas.

[0012] Preferably, the carbon source added by the carbon source adding system is methanol or sodium acetate.

[0013] Preferably, the short-cut nitrification reactor is used to convert 50% of ammonia nitrogen in the wastewater into nitrite.

[0014] Preferably, the catalytic oxidation equipment is provided with an oxidant dosing system, and the oxidant added by the oxidant dosing system is one or more of hydrogen peroxide, permanganate, and persulfate.

[0015] Preferably, a filtering device is provided at the inlet of the catalytic oxidation device, and the filtering accuracy of the filtering device is 0.1-0.45 μm, so as to separate fine suspended particles in the wastewater.

[0016] Compared with the prior art, the advantages of the utility model are:

[0017] According to the characteristics of pollutants in wastewater, the utility model adopts the "precision filtration + catalytic oxidation + denitrification" process for pretreatment. On the one hand, it reduces the concentration of organic pollutants in wastewater and converts them into short-chain low-molecular organic matter, which is conducive to further treatment by the subsequent biological treatment system; on the other hand, it adopts a denitrification reactor for pre-denitrification to reduce the subsequent system processing load;

[0018] The biological treatment stage adopts the combined process of "membrane bioreactor + short-cut nitrification reactor + anaerobic ammonium oxidation reactor" for treatment. First, the membrane bioreactor is used for carbonization reaction to reduce the concentration of organic pollutants in the wastewater and improve the stability of system operation; secondly, 50% of ammonia nitrogen is converted into nitrite through the short-cut nitrification reactor, and the lower aeration volume reduces the energy consumption of the system, while providing sufficient nitrite for anaerobic ammonium oxidation; the anaerobic ammonium oxidation reactor cultivates anaerobic ammonium oxidizing bacteria by adding carbon source, giving full play to its efficient denitrification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are not intended to be drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the utility model will be described by way of example and with reference to the accompanying drawings, in which:

[0020] Figure 1 It is a schematic diagram of a system for treating wastewater produced by phase change materials shown in the utility model. DETAILED DESCRIPTION

[0021] In order to better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0022] Combination Figure 1 As shown, the utility model proposes a system for treating phase change material production wastewater, including a pretreatment system 10, a biological treatment system 20 and a sludge dewatering system 30, wherein the purpose of the pretreatment system 10 is to remove suspended matter in the wastewater, reduce the concentration of ammonia nitrogen and promote the ring opening and chain breaking reactions of long-chain organic matter in the wastewater.

[0023] Specifically, the pretreatment system 10 includes a catalytic oxidation device 13 and a denitrification reactor 14. The catalytic oxidation device 13 is used to induce ring-opening and chain-breaking reactions of long-chain organic matter in the wastewater. The denitrification reactor 14 is used to react with ammonia nitrogen in the wastewater to reduce the ammonia nitrogen concentration in the wastewater.

[0024] Among them, the catalytic oxidation equipment 13 uses an oxidant dosing system to feed oxidants and catalysts into the equipment, and the oxidants and catalysts in the equipment cause the organic matter in the wastewater to undergo ring-opening and chain-breaking reactions; the denitrification reactor 14 reacts with the ammonia nitrogen in the wastewater by adding denitrifiers and additives to reduce the ammonia nitrogen concentration in the wastewater, which is beneficial to further treatment by the subsequent biological treatment system 20.

[0025] Optionally, the oxidant added to the catalytic oxidation device 13 is one or more of hydrogen peroxide, permanganate, and persulfate.

[0026] In a preferred embodiment, a filter device 12 is provided at the inlet of the catalytic oxidation device 13. The filter device 12 has a filtering accuracy of 0.1-0.45 μm and is used to separate fine suspended particles in the wastewater.

[0027] Furthermore, a regulating tank 11 is provided before the filtering device 12, and the regulating tank 11 is used to regulate the water quality and water volume of the wastewater inlet.

[0028] Furthermore, the biological treatment system 20 includes a membrane bioreactor 22, a short-cut nitrification reactor 23 and an anaerobic ammonium oxidation reactor 24, and the wastewater is treated in the membrane bioreactor 22, the short-cut nitrification reactor 23 and the anaerobic ammonium oxidation reactor 24 in sequence.

[0029] In an optional embodiment, the membrane bioreactor 22 controls the dissolved oxygen at 2-4 mg / L under aeration conditions, and utilizes aerobic microorganisms to adsorb and degrade organic pollutants in the wastewater; the short-range nitrification reactor 23 controls the dissolved oxygen at 0.5-1.0 mg / L under aeration conditions, and utilizes nitrite bacteria to convert 50% of the ammonia nitrogen in the wastewater into nitrite.

[0030] Furthermore, the anaerobic ammonium oxidation reactor is provided with a carbon source dosing system, which cultivates anaerobic ammonium oxidizing bacteria by adding a small amount of carbon source into the anaerobic ammonium oxidation reactor, and utilizes the carbon source to react the nitrite produced by the short-range nitrification reactor with ammonia nitrogen in the raw wastewater to generate nitrogen gas, thereby removing total nitrogen from the wastewater and ultimately achieving standard emissions.

[0031] Since the concentration of organic matter is too high, it has an adverse effect on the short-cut nitrification process in the short-cut nitrification reactor 23 and the anaerobic ammonium oxidation in the anaerobic ammonium oxidation reactor 24. Therefore, the membrane bioreactor 22 is first used to perform a carbonization reaction to reduce the concentration of organic pollutants in the wastewater and improve the stability of system operation.

[0032] Secondly, since the anaerobic ammonium oxidation reaction requires the ratio of nitrite to ammonia nitrogen in the wastewater to be close to 1:1, and the nitrite concentration in industrial wastewater is usually very low, which does not meet the conditions for the anaerobic ammonium oxidation reaction, a short-range nitrification reactor 23 is set after the membrane bioreactor 22. By controlling the dissolved oxygen at 0.5-1.0 mg / L, 50% of the ammonia nitrogen is converted into nitrite. The lower aeration volume reduces the energy consumption of the system and provides sufficient nitrite for anaerobic ammonium oxidation.

[0033] Furthermore, since anaerobic ammonium oxidizing bacteria are autotrophic denitrifying bacteria with slow growth and long generation cycle, a certain concentration of organic matter can promote the synergistic denitrification effect between anaerobic ammonium oxidizing bacteria and denitrifying bacteria, while too much organic matter causes heterotrophic denitrifying bacteria to multiply in large numbers, forming a substrate competition relationship with anaerobic ammonium oxidizing bacteria, resulting in limited growth of anaerobic ammonium oxidizing bacteria.

[0034] Therefore, the present application chooses to add a small amount of carbon source to the anaerobic ammonium oxidation reactor 24 to cultivate anaerobic ammonium oxidizing bacteria, so as to give full play to the denitrification effect of the anaerobic ammonium oxidation reactor.

[0035] Optionally, the carbon source is one of methanol, sodium acetate or other organic carbon sources.

[0036] Furthermore, an intermediate water tank 21 is provided before the membrane bioreactor 22 , the discharge end of the denitrification reactor 14 is connected to the intermediate water tank 21 , the sludge produced in the membrane bioreactor 22 is discharged into the sludge dewatering system 30 , and the filtrate produced by the sludge dewatering system 30 flows back to the intermediate water tank 21 .

[0037] In this way, the wastewater from the pretreatment system 10 enters the intermediate water tank 21, mixes with the filtrate of the sludge dewatering system 30, and enters the membrane bioreactor 22, the short-range nitrification reactor 23 and the anaerobic ammonium oxidation reactor 24 in sequence, undergoing carbonization reaction, nitrite reaction and anaerobic ammonium oxidation reaction respectively. Finally, the effluent meets the national emission standards and enters the next-level sewage treatment plant for treatment.

[0038] Among them, the remaining supernatant of the sludge dewatering system 30 enters the intermediate water tank for circulation treatment, and the dewatered sludge is sent to a qualified unit for treatment.

[0039] In combination with the above embodiments, the utility model adopts the "precision filtration + catalytic oxidation + denitrification" process for pretreatment according to the characteristics of pollutants in wastewater. On the one hand, the concentration of organic pollutants in wastewater is reduced and converted into short-chain small molecular organic matter, which is conducive to further treatment by the subsequent biological treatment system; on the other hand, a denitrification reactor is used for pre-denitrification to reduce the subsequent system processing load;

[0040] The biological treatment stage adopts the combined process of "membrane bioreactor + short-cut nitrification reactor + anaerobic ammonium oxidation reactor" for treatment. The membrane bioreactor is first used for carbonization reaction to improve the stability of system operation. The short-cut nitrification reactor converts 50% of ammonia nitrogen into nitrite, which reduces energy consumption on the one hand and provides sufficient nitrite for anaerobic ammonium oxidation on the other hand. The anaerobic ammonium oxidation reactor cultivates anaerobic ammonium oxidizing bacteria by adding carbon source to give full play to the denitrification effect of the anaerobic ammonium oxidation reactor.

[0041] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A system for treating wastewater from phase change material production, characterized in that: It comprises a pretreatment system (10), a biological treatment system (20) and a sludge dewatering system (30); The pretreatment system (10) comprises a catalytic oxidation device (13) and a denitrification reactor (14), wherein the catalytic oxidation device (13) is used to cause long-chain organic matter in the wastewater to undergo ring-opening and chain-breaking reactions to generate small-molecule organic matter, and the denitrification reactor (14) is used to react with ammonia nitrogen in the wastewater to reduce the ammonia nitrogen concentration in the wastewater; The biological treatment system (20) comprises a membrane bioreactor (22), a short-cut nitrification reactor (23) and an anaerobic ammonium oxidation reactor (24), and the wastewater is sequentially treated by passing through the membrane bioreactor (22), the short-cut nitrification reactor (23) and the anaerobic ammonium oxidation reactor (24); Sludge dewatering system (30); An intermediate water tank (21) is provided before the membrane bioreactor (22), the discharge end of the denitrification reactor (14) is connected to the intermediate water tank (21), the sludge produced in the membrane bioreactor (22) is discharged into the sludge dewatering system (30), and the filtrate produced by the sludge dewatering system (30) flows back to the intermediate water tank (21).

2. The system for treating wastewater from phase change material production according to claim 1, characterized in that: An aeration device is provided in the membrane bioreactor (22), and the aeration device is configured to make the dissolved oxygen of the wastewater in the membrane bioreactor (22) be 2-4 mg / L.

3. The system for treating wastewater from phase change material production according to claim 1, characterized in that: An aeration device is provided in the short-cut nitrification reactor (23), and the aeration device is configured to make the dissolved oxygen of the wastewater in the short-cut nitrification reactor (23) be 0.5-1.0 mg / L.

4. The system for treating wastewater from phase change material production according to claim 1, characterized in that: The anaerobic ammonium oxidation reactor (24) is provided with a carbon source dosing system for cultivating anaerobic ammonium oxidation bacteria to cause nitrite entering the anaerobic ammonium oxidation reactor (24) to react with ammonia nitrogen to generate nitrogen gas.

5. The system for treating wastewater from phase change material production according to claim 4, characterized in that: The carbon source added into the carbon source adding system is methanol or sodium acetate.

6. The system for treating wastewater from phase change material production according to claim 4, characterized in that: The short-cut nitrification reactor (23) is used to convert 50% of the ammonia nitrogen in the wastewater into nitrite.

7. The system for treating wastewater from phase change material production according to claim 1, characterized in that: The catalytic oxidation device (13) is provided with an oxidant dosing system, and the oxidant dosing system injects one or more of hydrogen peroxide, permanganate, and persulfate.

8. The system for treating wastewater from phase change material production according to claim 1, characterized in that: The inlet of the catalytic oxidation device (13) is provided with a filtering device (12), and the filtering accuracy of the filtering device (12) is 0.1-0.45 μm, which is used to separate fine suspended particles in the wastewater.

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