Synchronous nitrogen and phosphorus removal sewage treatment device and method

Abstract

The invention relates to the technical field of sewage treatment, and discloses a synchronous nitrogen and phosphorus removal sewage treatment device and method.The method comprises the steps that modified three-dimensional net-shaped PVDC filler, composite sulfur autotrophic particulate matter, sulfur autotrophic denitrifying bacteria and anaerobic ammonium oxidation bacteria are mixed and granulated into specially-made filler, the specially-made filler is filled into HDPE floating balls with perforated structures, and then nitrogen and phosphorus are removed synchronously; the floating ball is further immersed in the anaerobic tank, so that the sewage treatment device is obtained, and synchronous nitrogen and phosphorus removal in the sewage treatment process is realized. The device can realize that ammonia nitrogen is less than or equal to 1mg / L and total phosphorus is less than or equal to 0.1 mg / L within 5 hours of hydraulic retention time, and is suitable for sewage upgrading and reconstruction and low-carbon operation scenes.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and specifically to a sewage treatment device and method for simultaneous nitrogen and phosphorus removal. Background Art

[0002] In traditional sewage treatment processes, nitrogen and phosphorus removal rely on multi-stage reaction tanks (such as AO and AAO processes), which have problems such as long process flow, high carbon source demand, large sludge production, and high energy consumption. Although the existing sulfur autotrophic denitrification technology can reduce the addition of carbon sources, it is difficult to achieve efficient removal of ammonia nitrogen and nitrate nitrogen simultaneously; anaerobic ammonium oxidation technology relies on stable nitrite nitrogen (NO2 - ) supply, while short-cut denitrification (NO3 - →NO2 - ) is difficult to stably control. In addition, existing fillers have problems such as easy detachment of biofilm, low mass transfer efficiency, and insufficient simultaneous phosphorus removal capacity.

[0003] Therefore, it is necessary to further improve the existing technology and develop a sewage treatment device and method with a short process flow, low energy consumption, no need for an external carbon source, and simultaneous denitrification and phosphorus removal, so as to achieve sewage upgrading and tail water discharge that meets the standards. Summary of the Invention

[0004] In summary, the present application aims to provide a sewage treatment device and method for simultaneous denitrification and phosphorus removal. By mixing and granulating a modified three-dimensional mesh PVDC filler, composite sulfur autotrophic particles, sulfur autotrophic denitrifying bacteria and anaerobic ammonia oxidizing bacteria into a special filler, and filling the special filler into a HDPE float with a perforated structure, and further immersing the float in an anaerobic tank, a sewage treatment device is obtained, which realizes simultaneous denitrification and phosphorus removal in the sewage treatment process. The device can achieve ammonia nitrogen ≤ 1 mg / L and total phosphorus ≤ 0.1 mg / L within a hydraulic retention time of 5 hours, and is suitable for sewage upgrading and low-carbon operation scenarios.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] In the first aspect, the present application provides a sewage treatment device for simultaneous nitrogen and phosphorus removal, the device comprising an anaerobic tank provided with a liquid inlet and a liquid outlet; corresponding racks are installed above and below the interior of the anaerobic tank; an HDPE float filled with special filler is immersed below the liquid level of the anaerobic tank; the special filler comprises a modified three-dimensional mesh PVDC filler and sulfur-autotrophic denitrifying bacteria, anaerobic ammonia-oxidizing bacteria and composite sulfur-autotrophic particulate matter attached to the modified three-dimensional mesh PVDC filler; the raw materials of the modified three-dimensional mesh PVDC filler comprise polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and a phosphorus-containing heat stabilizer.

[0007] In a second aspect, the present application provides a method for treating wastewater with simultaneous denitrification and phosphorus removal, which is implemented based on a wastewater treatment device with simultaneous denitrification and phosphorus removal, and includes the following steps:

[0008] The modified three-dimensional reticular PVDC filler is fixed inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed, thereby obtaining a modified three-dimensional reticular PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0009] The pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed and granulated to obtain composite sulfur autotrophic particles;

[0010] The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler;

[0011] The HDPE float ball filled with special filler is suspended on a rack set in the anaerobic tank through a stainless steel locking ring, thereby obtaining the sewage treatment device;

[0012] The influent is preliminarily filtered, the pH is adjusted to 6.5-8.5, the water temperature is controlled at 25-35°C, and then introduced into the sewage treatment device;

[0013] Under the condition of DO≤0.2mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled to be 3 to 5h;

[0014] The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 50-80% of the sludge flows back to the sewage treatment device.

[0015] Compared with the prior art, the advantages of this application include:

[0016] 1. Efficient simultaneous nitrogen and phosphorus removal

[0017] Sulfur autotrophic short-range denitrification: Utilize the sulfide (such as S 2- or S 0 ) as electron donor, and nitrate (NO3 - ) is reduced to nitrogen (N2) to complete denitrification. This process does not require an organic carbon source and directly uses sulfur as energy, which can significantly reduce energy consumption. In addition, the calcite powder in the composite sulfur autotrophic particles can slowly release Ca 2+ and HCO3 - , neutralize the acidic products (such as H +) to maintain a stable pH in the system and prevent inhibition of microbial activity. Finally, the composite particles formed by mixing and granulating pyrite powder, magnetite powder, calcite powder, sulfur powder, and a catalyst have internal micropores and a rough surface structure, which provides more attachment sites for microorganisms and increases the colony density per unit volume.

[0018] Anaerobic ammonium oxidation: Under anaerobic conditions, anaerobic ammonium oxidizing bacteria directly convert ammonia nitrogen (NH4 + ) and nitrite (NO2 - ) is converted into nitrogen (N2), greatly simplifying the traditional nitrification-denitrification process.

[0019] Modified three-dimensional network PVDC filler: The modified three-dimensional network PVDC filler is made by melt blending polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and phosphorus-containing heat stabilizer. Its surface hydrophilicity and biocompatibility are excellent, which can provide an ideal colonization interface for sulfur autotrophic denitrifying bacteria and anaerobic ammonia oxidizing bacteria, and promote biofilm formation. In addition, its high porosity also helps to provide more microbial (sulfur autotrophic denitrifying bacteria and anaerobic ammonia oxidizing bacteria) attachment sites, promoting sulfur autotrophic short-range denitrification and anaerobic ammonia oxidation reactions; it can also enrich phosphate (PO43-) through physical adsorption and chemical bonding, thereby facilitating the release of Fe by pyrite powder and magnetite powder in the reaction. 2+ / Fe 3+ It then further combines with phosphate to form a precipitate, promoting the immobilization of phosphorus and achieving chemical phosphorus removal.

[0020] Sulfur autotrophic denitrification and anaerobic ammonium oxidation complement each other. The former treats the remaining nitrate and the latter treats the ammonia nitrogen, jointly achieving efficient nitrogen removal. The modified three-dimensional mesh PVDC filler simultaneously adsorbs phosphorus, forming an integrated "denitrification + phosphorus removal" mechanism.

[0021] 2. Ultra-short hydraulic retention time

[0022] Among the specially made fillers, the modified three-dimensional reticular PVDC filler and the composite sulfur autotrophic particles can provide a large specific surface area, thereby significantly increasing the amount of microbial attachment. As a result, the concentration of active bacteria per unit volume in the sewage treatment device is high and the reaction rate is accelerated. At the same time, the perforated structure of the HDPE float helps to form turbulence, reduce the thickness of the diffusion boundary layer, and make pollutants (NH4 + 、NO3 - PO4 3- The synergy between the two can significantly increase mass transfer efficiency and shorten the reaction cycle, so only an ultra-short hydraulic retention time (3 to 5 hours) is required to achieve efficient nitrogen and phosphorus removal.

[0023] 3. Strong bacterial survival ability

[0024] Microorganisms attach to the filler, which is further filled into the HDPE float, which can avoid hydraulic shear and direct impact of toxic substances, and greatly improve the survival rate of the bacterial colony.

[0025] 4. Modular design and easy maintainability

[0026] The HDPE floats are connected in series via stainless steel locking rings, clips or chains, enabling quick installation and replacement, and can be further prefabricated into modular units using molds. Furthermore, an internal grid can be formed between the series-connected floats to intercept filler particles and prevent filler loss due to water erosion. Finally, the modified three-dimensional mesh PVDC filler can restore its adsorption properties through backwashing, extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the sewage treatment device for synchronous denitrification and phosphorus removal by sulfur autotrophic short-range denitrification and anaerobic ammonia oxidation float. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions, and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the following examples. However, this should not be construed as limiting the scope of this application to the following examples. Without departing from the above-mentioned method concepts of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0029] In this application, the terms used in this application are for the purpose of describing specific embodiments only and are not intended to be limiting of the application.

[0030] The terms “first” and “second” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0031] Furthermore, as used in this application and the appended claims, the singular forms "for," "or," "an," "any," and "said" are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] In the first aspect, the present application provides a sewage treatment device for simultaneous nitrogen and phosphorus removal, the device being Figure 1As shown, it includes an anaerobic tank 3 provided with a liquid inlet 1 and a liquid outlet 2; a frame 4 is installed above and below the inside of the anaerobic tank 3; an HDPE float 6 filled with a special filler 5 is immersed below the liquid level of the anaerobic tank 3; the special filler 5 includes a modified three-dimensional mesh PVDC filler and sulfur autotrophic denitrifying bacteria, anaerobic ammonia oxidizing bacteria and composite sulfur autotrophic particles attached to the modified three-dimensional mesh PVDC filler; the raw materials of the modified three-dimensional mesh PVDC filler include polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and a phosphorus-containing heat stabilizer.

[0033] In one possible implementation, the method for preparing the modified three-dimensional network PVDC filler includes:

[0034] The polyvinylidene chloride, polyhydroxyalkyl ester and maleic anhydride grafted polyethylene were vacuum dried at 60-80°C for 2-3h;

[0035] Add the dried polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and phosphorus-containing heat stabilizer into a high-speed mixer, and premix at 15-20 Hz for 30-60 minutes to obtain a premix;

[0036] The premix is added into a twin-screw extruder, blended and melted at 180-200° C., and extruded into granules to obtain modified PVDC granules;

[0037] The modified PVDC particles are melt-spun at 170-190° C., and a circular or shaped spinneret with a pore size of 1-2 mm is selected to produce the modified PVDC fibers.

[0038] The modified PVDC fibers are bonded with glue to obtain a modified three-dimensional network PVDC filler;

[0039] The mass ratio of the polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and phosphorus-containing heat stabilizer is (50-70): (10-30): (5-10): (5-15).

[0040] In a possible implementation, the polyhydroxyalkanoate includes at least one of polyhydroxybutyrate, polyhydroxyvalerate, and polyhydroxyoctanoate.

[0041] In a possible implementation, the phosphorus-containing heat stabilizer includes at least one of triethyl phosphate, tricresyl phosphate, trioctyl phosphite, and triphenyl phosphite.

[0042] In a possible implementation, the mass ratio of the modified three-dimensional reticulated PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is (40-60): (30-50): (5-15): (5-15).

[0043] In a possible implementation, the particle size of the composite sulfur autotrophic particles ranges from 3 to 5 mm; the composite sulfur autotrophic particles are obtained by mixing pyrite powder, magnetite powder, calcite powder, sulfur powder and a catalyst and then granulating the mixture.

[0044] In one possible implementation, the mass ratio of the pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst is (1-12):(1-3):(1-3):3:(1-3); and the catalyst includes at least one of copper oxide and zinc oxide.

[0045] In a possible implementation, the filling rate of the special filler 5 in the HDPE float 6 is 20-30%; and the porosity of the modified three-dimensional network PVDC filler is ≥96%.

[0046] In a possible implementation, the HDPE float 6 is suspended on the frame 4 via a stainless steel locking ring 7 ; a perforated structure 8 is also provided on the HDPE float 6 .

[0047] In a possible implementation, the anaerobic ammonia oxidizing bacteria are attached to the modified three-dimensional mesh PVDC filler in advance through the culture tank of the enrichment unit.

[0048] In one possible implementation, the enrichment unit includes one or more culture tanks, a special nutrient matrix filled inside the culture tank, a modified three-dimensional mesh PVDC filler fixed inside the culture tank, and dispersed anaerobic ammonia-oxidizing bacteria; the one or more culture tanks are connected in series; and the special nutrient matrix circulates in the one or more culture tanks.

[0049] In one possible implementation, the special nutrient matrix includes 80-160 mg / L methanol, 35-50 mg / L NH4+-N, 35-65 mg / L NO3--N, 300-500 mg / L sodium bicarbonate, 120-180 mg / L calcium chloride, 15-25 mg / L potassium dihydrogen phosphate, 0-5 mg / L leucine, 0-2 mg / L lysine, 0-2 mg / L aspartic acid, 0-2 mg / L glutamic acid and 0-5 mg / L trace elements.

[0050] In a possible implementation, the trace element includes at least one of iron, zinc, manganese, copper and molybdenum.

[0051] In a second aspect, the present application provides a method for treating wastewater with simultaneous denitrification and phosphorus removal, which is implemented based on a wastewater treatment device with simultaneous denitrification and phosphorus removal, and includes the following steps:

[0052] The modified three-dimensional reticular PVDC filler is fixed inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed, thereby obtaining a modified three-dimensional reticular PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0053] The pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed and granulated to obtain composite sulfur autotrophic particles;

[0054] The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0055] The HDPE float 6 filled with special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0056] The influent is preliminarily filtered, the pH is adjusted to 6.5-8.5, the water temperature is controlled at 25-35°C, and then introduced into the sewage treatment device;

[0057] Under the condition of DO≤0.2mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled to be 3 to 5h;

[0058] The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 50-80% of the sludge flows back to the sewage treatment device.

[0059] The following will describe in detail a sewage treatment device and method for simultaneous nitrogen and phosphorus removal provided by the present application in combination with different examples.

[0060] Example 1:

[0061] like Figure 1 As shown, a sewage treatment device and method for simultaneous nitrogen and phosphorus removal includes the following steps:

[0062] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0063] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 1:1:1:3:1 and granulated to obtain composite sulfur autotrophic granules;

[0064] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0065] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 45:35:10:10;

[0066] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0067] 5. Perform preliminary filtration on the incoming water, adjust the pH to 6.5, control the water temperature at 25°C, and pass it into the sewage treatment device;

[0068] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 3 hours;

[0069] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 50% of the sludge is returned to the sewage treatment device.

[0070] Example 2:

[0071] like Figure 1 As shown, a sewage treatment device and method for simultaneous nitrogen and phosphorus removal includes the following steps:

[0072] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0073] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 3:2:2:3:2 and granulated to obtain composite sulfur autotrophic granules;

[0074] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0075] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 50:40:5:5;

[0076] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0077] 5. Perform preliminary filtration on the incoming water, adjust the pH to 7.0, control the water temperature at 30°C, and pass it into the sewage treatment device;

[0078] 6. Under the condition of DO ≤ 0.2 mg / L, control the hydraulic retention time of the influent in the sewage treatment device to 4 hours;

[0079] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 60% of the sludge is returned to the sewage treatment device.

[0080] Example 3:

[0081] like Figure 1 As shown, a sewage treatment device and method for simultaneous nitrogen and phosphorus removal includes the following steps:

[0082] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0083] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 6:3:3:3:3 and granulated to obtain composite sulfur autotrophic granules;

[0084] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0085] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 40:30:15:15;

[0086] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0087] 5. Perform preliminary filtration on the incoming water, adjust the pH to 8.0, control the water temperature at 35°C, and pass it into the sewage treatment device;

[0088] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 4.5 h;

[0089] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 70% of the sludge is returned to the sewage treatment device.

[0090] Example 4:

[0091] like Figure 1 As shown, a sewage treatment device and method for simultaneous nitrogen and phosphorus removal includes the following steps:

[0092] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0093] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 8:1:2:3:1 and granulated to obtain composite sulfur autotrophic granules;

[0094] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0095] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 40:40:8:12;

[0096] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0097] 5. Perform preliminary filtration on the incoming water, adjust the pH to 7.5, control the water temperature at 28°C, and pass it into the sewage treatment device;

[0098] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 3.5 h;

[0099] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 55% of the sludge is returned to the sewage treatment device.

[0100] Example 5:

[0101] like Figure 1 As shown, a sewage treatment device and method for simultaneous nitrogen and phosphorus removal includes the following steps:

[0102] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0103] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 10:2:1:3:2 and granulated to obtain composite sulfur autotrophic granules;

[0104] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0105] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 50:30:12:8;

[0106] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0107] 5. Perform preliminary filtration on the incoming water, adjust the pH to 6.8, control the water temperature at 32°C, and pass it into the sewage treatment device;

[0108] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 4.5 h;

[0109] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 75% of the sludge is returned to the sewage treatment device.

[0110] Example 6:

[0111] like Figure 1 As shown, a sewage treatment device and method for simultaneous nitrogen and phosphorus removal includes the following steps:

[0112] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0113] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 12:3:1:3:3 and granulated to obtain composite sulfur autotrophic granules;

[0114] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0115] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 40:35:10:15;

[0116] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0117] 5. Perform preliminary filtration on the incoming water, adjust the pH to 8.5, control the water temperature at 33°C, and pass it into the sewage treatment device;

[0118] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 5 hours;

[0119] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 80% of the sludge is returned to the sewage treatment device.

[0120] Comparative Example 1:

[0121] A sewage treatment device and method for simultaneous nitrogen and phosphorus removal comprises the following steps:

[0122] 1. Fixing the sheet-like PVDC filler inside the culture tank where anaerobic ammonium oxidizing bacteria are dispersed to obtain the sheet-like PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0123] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 1:1:1:3:1 and granulated to obtain composite sulfur autotrophic granules;

[0124] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the sheet-like PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0125] The mass ratio of the flaky PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 45:35:10:10;

[0126] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0127] 5. Perform preliminary filtration on the incoming water, adjust the pH to 6.5, control the water temperature at 25°C, and pass it into the sewage treatment device;

[0128] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 3 hours;

[0129] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 50% of the sludge is returned to the sewage treatment device.

[0130] Comparative Example 2:

[0131] A sewage treatment device and method for simultaneous nitrogen and phosphorus removal comprises the following steps:

[0132] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0133] 2. Pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed in a mass ratio of 6:3:3:3:3 and granulated to obtain composite sulfur autotrophic granules;

[0134] 3. The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler 5;

[0135] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 40:30:15:15;

[0136] 4. Disperse the special filler 5 directly into the anaerobic tank 3;

[0137] 5. Perform preliminary filtration on the incoming water, adjust the pH to 8.0, control the water temperature at 35°C, and pass it into the sewage treatment device;

[0138] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 4.5 h;

[0139] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 70% of the sludge is returned to the sewage treatment device.

[0140] Comparative Example 3:

[0141] A sewage treatment device and method for simultaneous nitrogen and phosphorus removal comprises the following steps:

[0142] 1. Fixing the modified three-dimensional reticulated PVDC filler inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed to obtain a modified three-dimensional reticulated PVDC filler inoculated with anaerobic ammonium oxidizing bacteria;

[0143] 2. Mix pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst in a mass ratio of 12:3:1:3:3;

[0144] 3. A mixture of pyrite powder, magnetite powder, calcite powder, sulfur powder, and a catalyst and sulfur autotrophic denitrifying bacteria are further attached to a modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia-oxidizing bacteria to obtain a special filler 5;

[0145] The mass ratio of the modified three-dimensional reticular PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is 40:35:10:15;

[0146] 4. The HDPE float 6 filled with the special filler 5 is suspended on the frame 4 set in the anaerobic tank 3 through the stainless steel lock ring 7, thus obtaining the sewage treatment device;

[0147] 5. Perform preliminary filtration on the incoming water, adjust the pH to 8.5, control the water temperature at 33°C, and pass it into the sewage treatment device;

[0148] 6. Under the condition of DO ≤ 0.2 mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled at 5 hours;

[0149] 7. The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 80% of the sludge is returned to the sewage treatment device.

[0150] Refer to HJ 535-2009 to determine the NH4 content of wastewater before and after anaerobic ammonium oxidation rapid start-up + -N content; refer to HJ / T346-2007 to determine the NO3--N content of sewage before and after anaerobic ammonium oxidation rapid start-up; refer to GB 11893-89 to determine the total phosphorus (TP) content of sewage before and after treatment.

[0151] By testing the NH4 content of sewage before and after treatment + -N content, NO3--N content and total phosphorus (TP) content, so as to calculate the removal rate of the corresponding indicators.

[0152] Table 1. NH4 in sewage inlet and outlet + -N content and NH4 + -N removal rate

[0153] <![CDATA[NH4+-N content in influent (mg / L)]]> <![CDATA[NH4+-N content in effluent (mg / L)]]> <![CDATA[NH4+-N removal rate (%)]]> Example 1 20 0.54 97.30 Example 2 20 0.73 96.35 Example 3 20 0.66 96.70 Example 4 20 0.82 95.90 Example 5 20 0.77 96.15 Example 6 20 0.58 97.1 Comparative Example 1 20 4.56 77.20 Comparative Example 2 20 5.91 70.45 Comparative Example 3 20 3.37 83.15

[0154] Table 2. NO3--N content and NO3--N removal rate of sewage inlet and outlet

[0155]

[0156]

[0157] Table 3. Total phosphorus (TP) content and removal rate of sewage influent and effluent

[0158]

[0159] It can be seen from Tables 1 to 3 that the NH4 + -N removal rate, NO3--N removal rate and total phosphorus (TP) removal rate are much higher than those of comparative examples 1 to 3.

[0160] This is because in Examples 1-6, a wastewater treatment device was created by mixing and granulating a modified three-dimensional reticulated PVDC filler, composite sulfur autotrophic particles, sulfur autotrophic denitrifying bacteria, and anaerobic ammonium oxidizing bacteria into a specialized filler. This filler was then filled into a perforated HDPE float, which was then immersed in an anaerobic tank. Sulfur autotrophic denitrification and anaerobic ammonium oxidation complement each other, with the former treating excess nitrate and the latter treating ammonia nitrogen, jointly achieving efficient nitrogen removal. The modified three-dimensional reticulated PVDC filler also simultaneously adsorbs phosphorus, forming an integrated "denitrification + phosphorus removal" mechanism, ultimately achieving simultaneous denitrification and phosphorus removal during wastewater treatment.

[0161] In Comparative Example 1, modified three-dimensional reticular PVDC filler was not used, but sheet PVDC filler was used instead. Therefore, its surface does not have excellent hydrophilicity and biocompatibility, and cannot provide an ideal colonization interface for sulfur autotrophic denitrifying bacteria and anaerobic ammonia oxidizing bacteria; nor can it provide more attachment sites for microorganisms (sulfur autotrophic denitrifying bacteria and anaerobic ammonia oxidizing bacteria), so sulfur autotrophic short-range denitrification and anaerobic ammonia oxidation reactions are difficult to promote; and it is difficult to enrich phosphate (PO43-) through physical adsorption and chemical bonding, which is not conducive to phosphorus fixation and chemical phosphorus removal. Therefore, the final NH4 + -N removal rate, NO3--N removal rate and total phosphorus (TP) removal rate were all low.

[0162] In Comparative Example 2, the special filler 5 was not filled into the HDPE float 6, but was directly dispersed into the anaerobic tank 3. Therefore, it was difficult to avoid the direct impact of hydraulic shear and toxic substances on the bacterial colony, which greatly reduced the survival rate of the bacterial colony; and it was also impossible to avoid the loss of filler due to water erosion. + -N removal rate, NO3--N removal rate and total phosphorus (TP) removal rate were the lowest.

[0163] In Comparative Example 3, instead of using composite sulfur autotrophic particles, a mixture of pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst was directly used. Therefore, composite particles with internal micropores and surface roughness could not be formed by mixing and granulating, resulting in fewer microbial attachment sites and lower colony density per unit volume. + -N removal rate, NO3--N removal rate and total phosphorus (TP) removal rate are also low.

[0164] The above results show and describe the basic principles and main features of this application as well as the advantages of this application.

[0165] Those skilled in the art should understand that the present application is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements may be made to the present application, such as the production of raw materials for the biochemical industry based on the present method or an improved method of the present method. Such changes and improvements fall within the scope of the present application. The scope of protection claimed in the present application is defined by the equivalents of the appended claims.

Claims

1. A sewage treatment device for simultaneous nitrogen and phosphorus removal, characterized in that: The device comprises an anaerobic tank (3) provided with a liquid inlet (1) and a liquid outlet (2); racks (4) are installed correspondingly above and below the interior of the anaerobic tank (3); an HDPE float (6) filled with a special filler (5) is immersed below the liquid level of the anaerobic tank (3); the special filler (5) comprises a modified three-dimensional reticular PVDC filler and sulfur autotrophic denitrifying bacteria, anaerobic ammonia oxidizing bacteria and composite sulfur autotrophic particles attached to the modified three-dimensional reticular PVDC filler; the raw materials of the modified three-dimensional reticular PVDC filler include polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and a phosphorus-containing heat stabilizer.

2. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 1, characterized in that: The preparation method of the modified three-dimensional network PVDC filler comprises: The polyvinylidene chloride, polyhydroxyalkyl ester and maleic anhydride grafted polyethylene were vacuum dried at 60-80°C for 2-3h; Add the dried polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and phosphorus-containing heat stabilizer into a high-speed mixer, and premix at 15-20 Hz for 30-60 minutes to obtain a premix; The premix is added into a twin-screw extruder, blended and melted at 180-200° C., and extruded into granules to obtain modified PVDC granules; The modified PVDC particles are melt-spun at 170-190° C., and a circular or shaped spinneret with a pore size of 1-2 mm is selected to produce the modified PVDC fibers. The modified PVDC fibers are bonded with glue to obtain a modified three-dimensional network PVDC filler; The mass ratio of the polyvinylidene chloride, polyhydroxyalkyl ester, maleic anhydride grafted polyethylene and phosphorus-containing heat stabilizer is (50-70): (10-30): (5-10): (5-15).

3. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 1, characterized in that: The mass ratio of the modified three-dimensional network PVDC filler, the composite sulfur autotrophic particles, the sulfur autotrophic denitrifying bacteria and the anaerobic ammonia oxidizing bacteria is (40-60): (30-50): (5-15): (5-15).

4. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 1, characterized in that: The particle size of the composite sulfur autotrophic granules ranges from 3 to 5 mm; the composite sulfur autotrophic granules are obtained by mixing pyrite powder, magnetite powder, calcite powder, sulfur powder and a catalyst and then granulating the mixture.

5. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 4, characterized in that: The mass ratio of the pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst is (1-12):(1-3):(1-3):3:(1-3); the catalyst includes at least one of copper oxide and zinc oxide.

6. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 1, characterized in that: The filling rate of the special filler (5) in the HDPE float (6) is 20-30%; the HDPE float (6) is suspended on the frame (4) through a stainless steel lock ring (7); the HDPE float (6) is also provided with a perforated structure (8); the porosity of the modified three-dimensional mesh PVDC filler is ≥96%.

7. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 1, characterized in that: The anaerobic ammonia oxidizing bacteria pass through the culture tank of the enrichment unit and are attached to the modified three-dimensional mesh PVDC filler in advance.

8. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 7, characterized in that: The enrichment unit includes one or more culture tanks, which are filled with a special nutrient matrix. A modified three-dimensional mesh PVDC filler is fixed inside the culture tank and anaerobic ammonia-oxidizing bacteria are dispersed therein; the one or more culture tanks are connected in series; and the special nutrient matrix circulates in the one or more culture tanks.

9. The sewage treatment device for simultaneous nitrogen and phosphorus removal according to claim 7, characterized in that: The specially prepared nutrient matrix includes 80-160 mg / L methanol, 35-50 mg / L NH4 + -N, 35~65mg / L NO3 - -N, 300-500 mg / L sodium bicarbonate, 120-180 mg / L calcium chloride, 15-25 mg / L potassium dihydrogen phosphate, 0-5 mg / L leucine, 0-2 mg / L lysine, 0-2 mg / L aspartic acid, 0-2 mg / L glutamic acid and 0-5 mg / L trace elements; the trace elements include at least one of iron, zinc, manganese, copper and molybdenum.

10. A wastewater treatment method for simultaneous denitrification and dephosphorization, which is implemented based on the wastewater treatment device for simultaneous denitrification and dephosphorization according to any one of claims 1 to 9, characterized in that: The steps include: The modified three-dimensional reticular PVDC filler is fixed inside a culture tank in which anaerobic ammonium oxidizing bacteria are dispersed, thereby obtaining a modified three-dimensional reticular PVDC filler inoculated with anaerobic ammonium oxidizing bacteria; The pyrite powder, magnetite powder, calcite powder, sulfur powder and catalyst are mixed and granulated to obtain composite sulfur autotrophic particles; The composite sulfur autotrophic particles and sulfur autotrophic denitrifying bacteria are further attached to the modified three-dimensional mesh PVDC filler inoculated with anaerobic ammonia oxidizing bacteria to obtain a special filler (5); The HDPE float (6) filled with the special filler (5) is suspended on the frame (4) set in the anaerobic tank (3) through the stainless steel lock ring (7), thereby obtaining the sewage treatment device; The influent is preliminarily filtered, the pH is adjusted to 6.5-8.5, the water temperature is controlled at 25-35°C, and then introduced into the sewage treatment device; Under the condition of DO≤0.2mg / L, the hydraulic retention time of the influent in the sewage treatment device is controlled to be 3 to 5h; The treated sewage enters the sedimentation tank or membrane module to separate the sludge and effluent. The effluent is discharged after the test indicators meet the standards, and 50-80% of the sludge flows back to the sewage treatment device.

Images