Anaerobic reaction system coupled with biological screening

Abstract

The invention discloses an anaerobic reaction system coupled with biological screening, and belongs to the technical field of water treatment. The system comprises an MSE biological screening device which comprises a first grid chamber, a second grid chamber, a third grid chamber and a fourth grid chamber which are sequentially connected and communicated; the first grid chamber is a stirring area; the second grid chamber is a first aeration area, the third grid chamber is a second aeration area, and the fourth grid chamber is an enhanced separation area; the first grid chamber is provided with a first water inlet, and the fourth grid chamber is provided with a first water outlet; a sludge reflux pump and a connecting pipeline are arranged between the first grid chamber and the fourth grid chamber; the HIC anaerobic reaction device comprises a reactor, and a first-stage decarburization area, a first three-phase separation assembly, a second-stage enhanced denitrification area, a second three-phase separation assembly and a third-stage purification area are sequentially arranged in the reactor from bottom to top; a second water inlet and a second water outlet are formed in the reactor, and the second water inlet is connected with the first water outlet through a pipeline.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to an anaerobic reaction system coupled with biological screening, which is mainly used for removing COD and TN pollutants in pharmaceutical wastewater and reducing the biochemical treatment load. Background Art

[0002] The hydrolysis reaction is the initial stage of the anaerobic reaction. It decomposes macromolecular organic matter that is difficult to be directly utilized by microorganisms into small molecular substances, providing a usable substrate for the subsequent anaerobic reaction stage. For example, when treating industrial wastewater, the hydrolysis reaction can convert the difficult biodegradable substances into easily biodegradable substances, improve the biodegradability of the wastewater, and facilitate the entire anaerobic reaction.

[0003] In order to solve the above problems, after searching, the patent document CN112960771A discloses a disclosed hydrolysis acidification and anaerobic composite ABR reactor and its application method, including a three-grid or four-grid rectangular pool body and a water collection tank in the pool, a baffle partition wall, a guide plate, a guide slope, a sediment removal pipe, a terminal water collection channel, and at most three downflow channels formed by the baffle partition wall between adjacent grids, and also includes a muddy water inlet pipe in the first grid and a connected upflow anaerobic water distributor; each grid has a water collection tank and a sediment removal pipe, and all grids except the first grid have guide plates and guide slopes; when working, the mixed liquid in the pool performs a reciprocating motion of upflow → downflow → the next upflow to achieve hydrolysis acidification and anaerobic composite reaction. The present invention has the advantages of streamlined process, excellent hydraulic flow state, no filler, no mixer, energy saving, high activated sludge concentration, low ORP, high acid production, high phosphorus release, high anaerobic reaction efficiency, simple operation and management, and low cost.

[0004] The above-mentioned patent discloses a hydrolysis-acidification and anaerobic composite ABR reactor, which can be used to remove some organic pollutants and promote phosphate-releasing bacteria to fully release phosphorus in cells for further denitrification and phosphorus removal in subsequent biochemical units. However, this patent is to treat organic pollutants in sewage and activated sludge rich in organic matter itself through anaerobic hydrolysis-acidification-fermentation biochemical reactions under the action of anaerobic microorganisms to generate soluble biodegradable organic matter (volatile fatty acids, etc.), and release phosphorus in cells through the action of phosphate-releasing bacteria, and does not involve denitrification. Summary of the invention

[0005] 1. Problem to be solved

[0006] In view of the technical problems in the prior art, the purpose of the present invention is to propose an anaerobic reaction system coupled with biological screening to promote partial COD (chemical oxygen demand) reduction, organic nitrogen ammoniation and nitrite formation, coordinate anaerobic reaction to regulate the anaerobic ammonium oxidation process, and realize the simultaneous denitrification and carbon removal of high organic nitrogen wastewater.

[0007] 2. Technical solution

[0008] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] The first aspect of the present invention provides an anaerobic reaction system coupled with biological screening, comprising:

[0010] The MSE biological screening device comprises a first cell, a second cell, a third cell and a fourth cell which are connected in sequence, wherein the volume ratio of the first cell, the second cell, the third cell and the fourth cell is 1-2:1:2-4:1.5-2; the first cell is a stirring zone; the second cell is a first aeration zone, the third cell is a second aeration zone, and the fourth cell is an enhanced separation zone; the first cell is provided with a first water inlet, and the fourth cell is provided with a first water outlet;

[0011] A sludge return pump and a connecting pipe are provided between the first cell and the fourth cell. The inventors were surprised to find that the high-efficiency external circulation system strengthens the internal sludge circulation, and the return ratio is between 100% and 300%, so as to promote the growth and metabolism of dominant microorganisms. In addition, the system strengthens the internal sludge circulation, increases the contact area between microorganisms and organic pollutants, enhances the mass transfer effect, and simultaneously promotes the activated sludge to undergo different microenvironmental zoning, domesticates and enriches functional microorganisms, exerts the biological screening function, and improves the biological treatment efficiency.

[0012] and a HIC anaerobic reaction device, comprising a reactor, wherein the reactor is provided with a primary decarbonization area, a first three-phase separation component, a secondary enhanced denitrification area, a second three-phase separation component and a third purification area in sequence from bottom to top;

[0013] The first-stage enhanced decarbonization reduces organic pollutants and lowers the C / N ratio; the third-stage purification area enhances water-solid-gas separation to avoid adverse interference with subsequent biochemical systems;

[0014] The reactor is provided with a second water inlet and a second water outlet, and the second water inlet is connected to the first water outlet through a pipeline.

[0015] According to any embodiment of the first aspect of the present invention, aeration pipes are provided at the bottom of the first aeration zone and the second aeration zone, wherein the length of the aeration pipes in the second aeration zone is greater than the length of the aeration pipes in the first aeration zone, and preferably, the length of the aeration pipes in the second aeration zone is twice the length of the aeration pipes in the first aeration zone.

[0016] According to any embodiment of the first aspect of the present invention, the first cell is provided with a stirring blade; the fourth cell is provided with an enhanced separation assembly, the enhanced separation assembly comprises a two-stage inclined plate, and the inclined plate has an inclination of 40 to 60 degrees. The fourth cell adopts a high-efficiency separation assembly to intercept the activated sludge, and the high-efficiency separation device in the enhanced separation zone intercepts most of the activated sludge, which can minimize the loss of microorganisms, maintain the abundance of the internal microbial population, and reduce its adverse effects on the microbial population structure inside the anaerobic reaction device.

[0017] According to any embodiment of the first aspect of the present invention, the first cell does not perform DO (dissolved oxygen) control; the second cell controls DO at 0.4-0.8 mg / L, preferably 0.5-0.6 mg / L, and the high aeration environment of the second cell can accelerate the decomposition and transformation of organic pollutants and organic nitrogen pollutants; the third cell controls DO at 0.2-0.4 mg / L.

[0018] By controlling the internal environment to a low DO environment, the formation of a micro-oxygen environment can increase the activity of microbial enzymes, strengthen the metabolic function of anaerobic bacteria, enhance their transformation and decomposition of organic pollutants, and increase the production of volatile fatty acids; at the same time, a low DO environment can inhibit the production of nitrates and promote the production of nitrites, while a slightly acidic pH environment can further stimulate the production of nitrites.

[0019] The DO environment in the third cell is lower than that in the second cell. Coupled with the buffering in the separation zone, its DO can be reduced to 0.1 mg / L or below, minimizing its adverse changes to the subsequent anaerobic environment.

[0020] According to any embodiment of the first aspect of the present invention, a circulation unit is arranged outside the secondary enhanced denitrification area, and the circulation unit includes a pH control tank and an external reflux pump, and the pH control tank and the external reflux pump are connected to the reactor through a pipeline; the secondary enhanced denitrification controls the reflux ratio of 200% to 400% to promote internal fluidization and enhance mass transfer.

[0021] According to any embodiment of the first aspect of the present invention, the internal pH value of the pH control tank is 7.0 to 8.0. Through external pH control, the anaerobic ammonia oxidation function is promoted to achieve simultaneous nitrogen removal and carbon removal.

[0022] According to any embodiment of the first aspect of the purpose of the present invention, the first three-phase separation component (230) / the second three-phase separation component (250) includes an air seal, a sedimentation zone and a reflux seam, wherein the angle of the reflux seam gas hood of the first three-phase separation component (230) is controlled at 45 to 55°, and the angle of the reflux seam gas hood of the second three-phase separation component (250) is controlled at 50 to 60°.

[0023] According to any embodiment of the first aspect of the present invention, the second water outlet is arranged on the top side of the tertiary purification area, and is connected to the first water inlet through a pipeline and a wastewater reflux pump. The effluent from the tertiary purification area is designed with a large reflux, and the reflux ratio is controlled at 50% to 200% to enhance the synergistic effect.

[0024] According to any embodiment of the first aspect of the present invention, a gas outlet is disposed at the top of the reactor.

[0025] According to any embodiment of the first aspect of the present invention, the pH of the inlet water of the first water inlet is controlled to be 5.0 to 7.0, preferably 6.0 to 6.5.

[0026] 3. Beneficial effects

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The anaerobic reaction system coupled with biological screening of the present invention realizes the mass production of nitrite through the front-end (MSE) biological screening device, coordinates the regulation of the internal anaerobic system, and promotes the anaerobic ammonia oxidation process; simultaneously utilizes the high volatile fatty acid production of the MSE biological screening device to achieve higher biogas production and energy benefits; at the same time, it promotes partial COD (chemical oxygen demand) reduction, organic nitrogen ammoniation and nitrite formation, coordinates the anaerobic reaction to regulate the anaerobic ammonia oxidation process, and can achieve simultaneous denitrification and carbon removal of high organic nitrogen wastewater.

[0029] (2) The anaerobic reaction system coupled with biological screening of the present invention, wherein the (MSE) biological screening device controls the dissolved oxygen gradient change (0.1-0.8 mg / L) through stirring and aeration design, regulates the internal biological microenvironment, coordinates the sludge to strengthen the internal circulation, strengthens the microbial action, and has a better macromolecule to small molecule conversion function than conventional hydrolysis and acidification, a higher volatile fatty acid production, and a stronger water quality buffering effect.

[0030] (3) Compared with the traditional anaerobic ammonia oxidation reaction system, the anaerobic reaction system coupled with biological screening of the present invention has a wider range of adaptability to wastewater quality, simpler parameter control, and more stable operating performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0032] Figure 1 It is a schematic structural diagram of the anaerobic reaction system coupled with biological screening of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of the enhanced separation component of the anaerobic reaction system coupled with biological screening of the present invention;

[0034] Figure 3 A schematic diagram of the structure of the HIC anaerobic reaction device of the anaerobic reaction system coupled with biological screening of the present invention;

[0035] Description of reference numerals:

[0036] 100, MSE biological screening device; 110, first cell; 111, first water inlet; 112, stirring blade; 120, second cell; 121, aeration pipe; 130, third cell; 140, fourth cell; 141, first water outlet; 142, enhanced separation component; 150, sludge return pump;

[0037] 200, HIC anaerobic reaction device; 210, reactor; 211, exhaust port; 220, primary decarbonization area; 221, second water inlet; 230, first three-phase separation component; 240, secondary enhanced denitrification area; 250, second three-phase separation component; 260, tertiary purification area; 261, second water outlet; 270, pH control tank; 280, external reflux pump; 290, wastewater reflux pump. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0041] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0042] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0043] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The anaerobic reaction system coupled with biological screening of this embodiment includes an MSE biological screening device 100 and an HIC anaerobic reaction device 200. Figure 1 As shown, the MSE biological screening device 100 includes a first cell 110, a second cell 120, a third cell 130 and a fourth cell 140 which are connected in sequence, and the volume ratio of the first cell 110, the second cell 120, the third cell 130 and the fourth cell 140 is 1-2:1:2-4:1.5-2; the first cell 110 is a stirring zone; the second cell 120 is a first aeration zone, the third cell 130 is a second aeration zone, and the fourth cell 140 is an enhanced separation zone; the first cell 110 is provided with a first water inlet 111, and the fourth cell 140 is provided with a first water outlet 141. The pH of the water inlet 111 can be controlled to be 5.0-7.0, preferably 6.0-6.5.

[0045] A sludge return pump 150 and a connecting pipe are provided between the first cell 110 and the fourth cell 140; the efficient external circulation system strengthens the internal sludge circulation, and the return ratio is between 100% and 300% to promote the growth and metabolism of dominant microorganisms; in addition, the efficient external circulation system strengthens the internal sludge circulation, increases the contact area between microorganisms and organic pollutants, enhances the mass transfer effect, and simultaneously promotes the activated sludge to undergo different microenvironmental zoning, domesticates and enriches functional microorganisms, exerts the biological screening function, and improves the biological treatment efficiency.

[0046] The HIC anaerobic reaction device 200 includes a reactor 210, wherein the reactor 210 is provided with a primary decarbonization area 220, a first three-phase separation component 230, a secondary enhanced denitrification area 240, a second three-phase separation component 250 and a tertiary purification area 260 from bottom to top; wherein the primary enhanced decarbonization reduces organic pollutants and reduces the C / N ratio; and the tertiary purification area strengthens water-solid-gas separation to avoid adverse interference with the subsequent biochemical system. In order to discharge the generated biogas, an exhaust port 211 is provided at the top of the reactor 210.

[0047] like Figure 1 As shown, the reactor 210 is provided with a second water inlet 221 and a second water outlet 261 , and the second water inlet 221 is connected to the first water outlet 141 through a pipeline.

[0048] The above-mentioned primary decarbonization area 220, secondary enhanced denitrification area 240 and tertiary purification area 260 can all adopt the structure of the existing technology, which will not be described in detail here.

[0049] As we all know, the first stage of anaerobic reaction is the hydrolysis stage, in which complex solid organic matter is broken down into small molecules by bacterial extracellular enzymes. For example, cellulose is hydrolyzed into disaccharides and glucose by cellulase, starch is broken down into maltose and glucose by amylase, and protein is hydrolyzed into short peptides and amino acids by protease. These small molecule hydrolyzates can be dissolved in water and pass through the cell membrane for use by bacteria.

[0050] The present invention reduces 30% to 40% of organic pollutants in wastewater through a front-end (MSE) biological screening device, promotes the generation of volatile fatty acids, organic nitrogen conversion and nitrite production; then enters the primary enhanced decarbonization system of the anaerobic reaction device, efficiently utilizes the easily metabolizable volatile fatty acids generated by the front end, increases biogas production, and further reduces COD. At the same time, anaerobic ammoniation can convert part of nitrate into nitrite and ammonia nitrogen, thereby reducing the C / N ratio and increasing the concentration of nitrite and ammonia nitrogen; then enters the secondary enhanced denitrification system, regulates the pH at 7.0 to 8.0, forms a favorable environment for anaerobic ammonia-oxidizing bacteria, promotes the anaerobic ammonia oxidation function, and achieves high denitrification efficiency.

[0051] The COD determination of the present invention can be carried out using the Yushan ultraviolet spectrometry UV254 self-cleaning COD sensor. The measuring principle is that many organic substances dissolved in water have an absorption effect on ultraviolet light. By measuring the degree of absorption of these organic substances to 254nm wavelength ultraviolet light, the total amount of organic pollutants in the water can be measured.

[0052] In this embodiment, Figure 1 In the embodiment, aeration pipes 121 are provided at the bottom of the first aeration zone and the bottom of the second aeration zone, wherein the length of the aeration pipes 121 in the second aeration zone is greater than that of the aeration pipes 121 in the first aeration zone. Preferably, the length of the aeration pipes 121 in the second aeration zone is twice that of the aeration pipes 121 in the first aeration zone.

[0053] Furthermore, the first cell 110 is provided with a stirring blade 112 for stirring, and other structures can also be used to achieve stirring, such as magnetic stirring, etc.; the fourth cell 140 is provided with a strengthening separation component 142, such as Figure 2 As shown, the enhanced separation assembly 142 includes two-stage inclined plates with an inclination of 40 to 60 degrees, preferably 45 degrees. The fourth cell 140 uses a high-efficiency separation assembly to intercept the activated sludge. The high-efficiency separation device in the enhanced separation zone intercepts most of the activated sludge, which can minimize the loss of microorganisms, maintain the abundance of the internal microbial population, and reduce its adverse effects on the microbial population structure inside the anaerobic reaction device.

[0054] Through a large number of experiments, the inventors were surprised that the first chamber 110 did not control DO (dissolved oxygen); the second chamber 120 controlled DO at 0.4-0.8 mg / L, and more preferably at 0.5-0.6 mg / L. The high aeration environment of the second chamber 120 can accelerate the decomposition and transformation of organic pollutants and organic nitrogen pollutants; the third chamber 130 controlled DO at 0.2-0.4 mg / L.

[0055] The possible reason is that by controlling the internal environment to a low DO environment, the formation of a micro-oxygen environment can increase the activity of microbial enzymes, strengthen the metabolic function of anaerobic bacteria, enhance their transformation and decomposition of organic pollutants, and increase the production of volatile fatty acids; at the same time, a low DO environment can inhibit the production of nitrates and promote the production of nitrites, and a slightly acidic pH environment can further stimulate the production of nitrites.

[0056] Furthermore, the inventors have found that the third cell 130 has a lower DO environment than the second cell 120, and due to the buffering in the separation zone, its DO can be reduced to 0.1 mg / L or below, thereby minimizing its adverse changes to the subsequent anaerobic environment.

[0057] A circulation unit is arranged outside the secondary enhanced denitrification area 240, and the circulation unit includes a pH control tank 270 and an external reflux pump 280, and the pH control tank 270 and the external reflux pump 280 are connected to the reactor 210 through a pipeline; the secondary enhanced denitrification controls the reflux ratio of 200% to 400% to promote internal fluidization and enhance mass transfer. The internal pH value of the pH control tank is 7.0 to 8.0. Through external pH control, the anaerobic ammonia oxidation function is promoted to achieve simultaneous denitrification and carbon removal.

[0058] In this embodiment, combined with Figure 1 and Figure 3 As shown, the first three-phase separation component (230) and the second three-phase separation component (250) include an air seal, a sedimentation zone and a reflow seam (not marked in the figure), wherein the angle of the reflow seam gas collecting hood of the first three-phase separation component (230) is controlled at 45 to 55 degrees, and the angle of the reflow seam gas collecting hood of the second three-phase separation component (250) is controlled at 50 to 60 degrees.

[0059] In addition, the second water outlet 261 is arranged on the top side of the tertiary purification area 260, and is connected to the first water inlet 111 through a pipeline and a wastewater reflux pump 290. The effluent from the tertiary purification area 260 is designed with a large reflux, and the reflux ratio is controlled at 50% to 200% to enhance the synergistic effect.

[0060] The present invention is further described in detail below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental materials and reagents used in the following examples can be obtained from commercial channels unless otherwise specified.

[0061] Example 1

[0062] The influent of the coupled biological screening anaerobic reaction system of this embodiment is actual pharmaceutical wastewater from an industrial park, with COD of about 8700 mg / L, total nitrogen (TN) of about 950 mg / L, and ammonia nitrogen concentration of about 360 mg / L.

[0063] The volume ratio of the first cell 110, the second cell 120, the third cell 130 and the fourth cell 140 of the MSE biological screening device 100 is designed to be 1:1:3:1.5 (the volume of the third cell 130 is 3 times that of the second cell 120), the DO of the first aeration zone is controlled at 0.5-0.6 mg / L, the DO of the second aeration zone is controlled at 0.2-0.3 mg / L, the pH of the influent is regulated at 5.0-6.0, and the sludge return ratio is controlled at 200%. The pH of the secondary enhanced denitrification area 240 of the HIC anaerobic reaction device 200 is controlled at 7.0-8.0, the return ratio is controlled at 250%, and the effluent return ratio of the tertiary purification zone is controlled at 100%.

[0064] The coupled biological screening anaerobic reaction system was operated continuously for 2 months, with the inlet COD of about 8700 mg / L, the effluent COD of the MSE device of about 5200 mg / L, and the COD removal rate of 40.23%. At the same time, the volatile acid concentration was about 2300 mg / L, the ammonia nitrogen concentration was about 420 mg / L, and the nitrite concentration was 210 mg / L. After HIC anaerobic treatment, the effluent COD was about 1000 mg / L, the COD removal rate was 80.77%, the effluent total nitrogen concentration was about 380 mg / L, the TN removal rate was about 60.0%, and the proportion of methane in biogas was 69.5%. The whole system achieved excellent simultaneous denitrification and carbon removal efficiency.

[0065] Example 2

[0066] The influent of the coupled biological screening anaerobic reaction system of this embodiment is actual pharmaceutical wastewater from an industrial park, with COD of about 8700 mg / L, total nitrogen (TN) of about 950 mg / L, and ammonia nitrogen concentration of about 360 mg / L.

[0067] The volume ratio of the first cell 110, the second cell 120, the third cell 130 and the fourth cell 140 of the MSE biological screening device 100 is designed to be 1:1.5:4:2, the DO of the secondary aeration zone is controlled at 0.6-0.8 mg / L, the DO of the tertiary aeration zone is controlled at 0.2-0.3 mg / L, the pH of the influent is regulated at 5.0-6.0, and the sludge return ratio is controlled at 250%. The pH of the secondary enhanced denitrification area 240 of the HIC device is controlled at 7.0-8.0, the return ratio is controlled at 200%, and the effluent return ratio of the tertiary purification area is controlled at 150%.

[0068] The coupled biological screening anaerobic reaction system was operated continuously for 2 months, with the inlet COD of about 8700 mg / L, the effluent COD of the MSE system of about 4800 mg / L, and the COD removal rate of 44.83%. At the same time, the volatile acid concentration was about 2200 mg / L, the ammonia nitrogen concentration was about 380 mg / L, and the nitrite concentration was 250 mg / L. After HIC anaerobic treatment, the effluent COD was about 750 mg / L, the COD removal rate was 84.38%, the effluent total nitrogen concentration was about 310 mg / L, the TN removal rate was about 67.37%, and the proportion of methane in biogas was 75.6%. The whole system achieved excellent simultaneous denitrification and carbon removal efficiency.

[0069] Comparative Example 1

[0070] The anaerobic reaction system of this comparative example has a structure that is different from that of Example 1, but does not have a sludge return design for the MSE device. The influent of the system is actual pharmaceutical wastewater from an industrial park, with a COD of about 8700 mg / L, a total nitrogen (TN) of about 950 mg / L, and an ammonia nitrogen concentration of about 360 mg / L.

[0071] The volume ratio of the first cell, the second cell, the third cell and the fourth cell of the MSE biological screening device is designed to be 1:1:3:1.5, the DO of the first aeration zone is controlled at 0.5-0.6 mg / L, the DO of the second aeration zone is controlled at 0.2-0.3 mg / L, the pH of the influent is regulated at 5.0-6.0, and the sludge return ratio is controlled at 0%. The pH of the secondary enhanced denitrification area 240 of the HIC device is controlled at 7.0-8.0, the return ratio is controlled at 250%, and the effluent return ratio of the tertiary purification area is controlled at 100%.

[0072] The anaerobic reaction system was operated continuously for 2 months, with the inlet COD of about 8700 mg / L, the effluent COD of the MSE device of about 6300 mg / L, and the COD removal rate of 27.59%. At the same time, the volatile acid concentration was about 1600 mg / L, the ammonia nitrogen concentration was about 490 mg / L, and the nitrite concentration was 130 mg / L. After HIC anaerobic treatment, the effluent COD was about 1500 mg / L, the COD removal rate was 76.19%, the effluent total nitrogen concentration was about 540 mg / L, the TN removal rate was about 43.16%, and the proportion of methane in biogas was 58.3%. The whole system achieved good simultaneous denitrification and carbon removal efficiency.

[0073] Comparative Example 2

[0074] The anaerobic reaction system of this comparative example has a structure that does not control HIC reflux and pH regulation compared to Example 1. The influent of the system is actual pharmaceutical wastewater from an industrial park, with a COD of about 8700 mg / L, a total nitrogen (TN) of about 950 mg / L, and an ammonia nitrogen concentration of about 360 mg / L.

[0075] The volume ratio of the first cell, the second cell, the third cell and the fourth cell of the MSE biological screening device is designed to be 1:1:3:1.5, the DO of the first aeration zone is controlled at 0.5-0.6 mg / L, the DO of the second aeration zone is controlled at 0.2-0.3 mg / L, the pH of the influent is regulated at 5.0-6.0, and the sludge return ratio is controlled at 200%. The return ratio of the secondary enhanced denitrification area 240 of the HIC device is controlled at 0%, and the effluent return ratio of the tertiary purification area is controlled at 100%.

[0076] The anaerobic reaction system was operated continuously for 2 months, with the inlet COD of about 8700 mg / L, the effluent COD of the MSE device of about 5400 mg / L, and the COD removal rate of 37.93%. At the same time, the volatile acid concentration was about 2100 mg / L, the ammonia nitrogen concentration was about 440 mg / L, and the nitrite concentration was 190 mg / L. After HIC anaerobic treatment, the effluent COD was about 1800 mg / L, the COD removal rate was 66.67%, the effluent total nitrogen concentration was about 650 mg / L, the TN removal rate was about 31.58%, and the proportion of methane in biogas was 63.7%. The whole system achieved good simultaneous denitrification and carbon removal efficiency.

[0077] Comparative Example 3

[0078] The structure of the anaerobic reaction system in this comparative example is different from that in Example 1. The MSE system DO control is not performed. The influent of the system is actual pharmaceutical wastewater from an industrial park, with a COD of about 8700 mg / L, a total nitrogen (TN) of about 950 mg / L, and an ammonia nitrogen concentration of about 360 mg / L.

[0079] The volume ratio of the first cell, the second cell, the third cell and the fourth cell of the MSE biological screening device is designed to be 1:1:3:1.5, the pH of the influent is regulated at 5.0-6.0, and the sludge return ratio is controlled at 200%. The pH of the secondary enhanced denitrification area 240 of the HIC device is controlled at 7.0-8.0, the return ratio is controlled at 250%, and the effluent return ratio of the tertiary purification area is controlled at 100%.

[0080] The anaerobic reaction system was operated continuously for 2 months, with the inlet COD of about 8700 mg / L, the effluent COD of the MSE device of about 7200 mg / L, and the COD removal rate of 17.24%. At the same time, the volatile acid concentration was about 800 mg / L, the ammonia nitrogen concentration was about 450 mg / L, and the nitrite concentration was 30 mg / L. After HIC anaerobic treatment, the effluent COD was about 3100 mg / L, the COD removal rate was 56.94%, the effluent total nitrogen concentration was about 880 mg / L, the TN removal rate was about 7.39%, and the proportion of methane in biogas was 48.9%. The whole system achieved a poor simultaneous denitrification and carbon removal efficiency.

[0081] Comparative Example 4

[0082] The anaerobic reaction system of this comparative example has a structure compared to Example 1, in which the MSE device is over-aerated. The influent of the system is actual pharmaceutical wastewater from an industrial park, with a COD of about 8700 mg / L, a total nitrogen (TN) of about 950 mg / L, and an ammonia nitrogen concentration of about 360 mg / L.

[0083] The volume ratio of the first cell, the second cell, the third cell and the fourth cell of the MSE biological screening device is designed to be 1:1:3:1.5, the DO of the first aeration zone is controlled at 2.0-3.0 mg / L, the DO of the second aeration zone is controlled at 1.5-2.0 mg / L, the pH of the influent is regulated at 5.0-6.0, and the sludge return ratio is controlled at 200%. The pH of the secondary enhanced denitrification area of ​​the HIC device is controlled at 7.0-8.0, the return ratio is controlled at 250%, and the effluent return ratio of the tertiary purification area is controlled at 100%.

[0084] The anaerobic reaction system was operated continuously for 2 months, with the influent COD of about 8700 mg / L, the effluent COD of the MSE system of about 4000 mg / L, and the COD removal rate of 54.02%. At the same time, the volatile acid concentration was about 2200 mg / L, the ammonia nitrogen concentration was about 180 mg / L, and the nitrite concentration was 10 mg / L. After HIC anaerobic treatment, the effluent COD was about 700 mg / L, the COD removal rate was 82.5%, the effluent total nitrogen concentration was about 910 mg / L, the TN removal rate was about 4.21%, and the proportion of methane in biogas was 64.7%. The whole system achieved excellent simultaneous denitrification and carbon removal efficiency.

[0085] Comparative Example 5

[0086] The structure of the anaerobic reaction system in this comparative example is different from that in Example 1, in which the MSE device configuration is changed. The influent of the system is actual pharmaceutical wastewater from an industrial park, with a COD of about 8700 mg / L, a total nitrogen (TN) of about 950 mg / L, and an ammonia nitrogen concentration of about 360 mg / L.

[0087] The volume ratio of the first cell, the second cell, the third cell and the fourth cell of the MSE biological screening device is designed to be 2:2:1:1, the DO of the first aeration zone is controlled at 0.5-0.6 mg / L, the DO of the second aeration zone is controlled at 0.2-0.3 mg / L, the pH of the influent is regulated at 5.0-6.0, and the sludge return ratio is controlled at 200%. The pH of the secondary enhanced denitrification area of ​​the HIC device is controlled at 7.0-8.0, the return ratio is controlled at 250%, and the effluent return ratio of the tertiary purification area is controlled at 100%.

[0088] The anaerobic reaction system was operated continuously for 2 months, with the inlet COD of about 8700 mg / L, the effluent COD of the MSE device of about 5400 mg / L, and the COD removal rate of 37.93%. At the same time, the volatile acid concentration was about 1900 mg / L, the ammonia nitrogen concentration was about 390 mg / L, and the nitrite concentration was 110 mg / L. After HIC anaerobic treatment, the effluent COD was about 1300 mg / L, the COD removal rate was 75.93%, the effluent total nitrogen concentration was about 660 mg / L, the TN removal rate was about 30.53%, and the proportion of methane in biogas was 61.8%. The whole system achieved good simultaneous denitrification and carbon removal efficiency.

[0089] The results of Examples 1-2 and Comparative Examples 1-5 are compared, as shown in the following table:

[0090] project COD removal rate TN removal rate Methane as a percentage of biogas Example 1 80.77％ 60.0％ 69.5％ Example 2 84.38％ 67.37％ 75.6％ Comparative Example 1 76.19％ 43.16％ 58.3％ Comparative Example 2 66.67％ 31.58％ 63.7％ Comparative Example 3 56.94％ 7.39％ 48.9％ Comparative Example 4 82.5％ 4.21％ 64.7％ Comparative Example 5 75.93％ 30.53％ 61.8％

[0091] Combined with the data analysis in the table, it is known that the anaerobic reaction system coupled with biological screening of the present invention can achieve higher biogas production and energy benefits; at the same time, it promotes partial COD (chemical oxygen demand) reduction, organic nitrogen ammoniation and nitrite formation, and coordinates anaerobic reactions to regulate the anaerobic ammonia oxidation process, which can achieve simultaneous denitrification and carbon removal of high organic nitrogen wastewater.

[0092] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An anaerobic reaction system coupled with biological screening, characterized in that: include: The MSE biological screening device (100) comprises a first cell (110), a second cell (120), a third cell (130) and a fourth cell (140) which are connected in sequence, wherein the volume ratio of the first cell (110), the second cell (120), the third cell (130) and the fourth cell (140) is 1-2:1:2-4:1.5-2; the first cell (110) is a stirring zone; the second cell (120) is a first aeration zone, the third cell (130) is a second aeration zone, and the fourth cell (140) is an enhanced separation zone; the first cell (110) is provided with a first water inlet (111), and the fourth cell (140) is provided with a first water outlet (141); a sludge return pump (150) and a connecting pipe are provided between the first cell (110) and the fourth cell (140); and a HIC anaerobic reaction device (200), comprising a reactor (210), wherein the reactor (210) is provided with a primary decarbonization region (220), a first three-phase separation component (230), a secondary enhanced denitrification region (240), a second three-phase separation component (250) and a tertiary purification region (260) in order from bottom to top; The reactor (210) is provided with a second water inlet (221) and a second water outlet (261), and the second water inlet (221) is connected to the first water outlet (141) via a pipeline.

2. The anaerobic reaction system coupled with biological screening according to claim 1, characterized in that: Aeration pipes (121) are provided at the bottom of the first aeration zone and the second aeration zone, wherein the length of the aeration pipes (121) of the second aeration zone is greater than the length of the aeration pipes (121) of the first aeration zone.

3. The anaerobic reaction system coupled with biological screening according to claim 2, characterized in that: The first cell (110) is provided with a stirring blade (112); the fourth cell (140) is provided with an enhanced separation component (142), and the enhanced separation component (142) comprises two-stage inclined plates, and the inclined plates have an inclination of 40 to 60 degrees.

4. The anaerobic reaction system coupled with biological screening according to any one of claims 1 to 3, characterized in that: The first cell (110) does not perform DO control; the second cell (120) controls DO at 0.4-0.8 mg / L; and the third cell (130) controls DO at 0.2-0.4 mg / L.

5. The anaerobic reaction system coupled with biological screening according to claim 4, characterized in that: A circulation unit is arranged outside the secondary enhanced denitrification area (240), and the circulation unit includes a pH control tank (270) and an external reflux pump (280). The pH control tank (270) and the external reflux pump (280) are connected to the reactor (210) through a pipeline.

6. The anaerobic reaction system coupled with biological screening according to claim 5, characterized in that: The internal pH value of the pH control tank (270) is 7.0-8.

0.

7. The anaerobic reaction system coupled with biological screening according to claim 6, characterized in that: The first three-phase separation component (230) / the second three-phase separation component (250) comprises an air seal, a sedimentation zone and a reflux seam, wherein the angle of the reflux seam gas collecting hood of the first three-phase separation component (230) is controlled at 45 to 55 degrees, and the angle of the reflux seam gas collecting hood of the second three-phase separation component (250) is controlled at 50 to 60 degrees.

8. The anaerobic reaction system coupled with biological screening according to claim 7, characterized in that: The second water outlet (261) is arranged on one side of the top of the tertiary purification area (260), and is connected to the first water inlet (111) through a pipeline and a wastewater return pump (290).

9. The anaerobic reaction system coupled with biological screening according to claim 8, characterized in that: The top of the reactor (210) is provided with an exhaust port (211).

10. The anaerobic reaction system coupled with biological screening according to claim 9, characterized in that: The pH of the water entering the first water inlet (111) is controlled to be between 5.0 and 7.0.

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