Sewage treatment device based on UASB (upflow anaerobic sludge blanket) process

Abstract

The utility model provides a sewage treatment device based on a UASB (Upflow Anaerobic Sludge Blanket) process, which relates to sewage treatment equipment and comprises a tank body, a reaction area, an electric biological treatment area and a settling area are sequentially arranged from the bottom to the top of the tank body, and the reaction area is communicated with the settling area through the electric biological treatment area; a granular sludge bed is arranged in the reaction area; the electro-biological treatment area is provided with a first electrode and a second electrode, and the first electrode and the second electrode are connected with a variable-frequency power supply through wires; periodically reversing the variable-frequency power supply; a water inlet pipe is arranged at the bottom of the tank body and is communicated with the reaction area; a water outlet pipe is arranged at the top of the tank body and is communicated with the settling area. Organic matters are decomposed through microorganisms on the granular sludge bed and converted into biogas, and an alternating-current electric field is generated through the first electrode, the second electrode and the variable-frequency power supply; in the electro-biological treatment area, denitrifying bacteria utilize organic matters as electron donors to reduce nitrate into nitrogen, so that denitrification is realized; meanwhile, the bacteria with the phosphorus removal function absorb and release phosphorus under the action of the electric field, and phosphorus removal is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to sewage treatment equipment, concretely relates to sewage treatment device based on UASB process. BACKGROUND

[0002] The biological treatment of sewage is one of the important technologies in the field of environmental protection at present, which mainly forms various efficient sewage treatment processes through aerobic treatment, anaerobic treatment and their combination. Among them, although anaerobic treatment and aerobic treatment can remove the reducing substances (COD) in the sewage, there are problems, the phosphorus release and absorption process of phosphorus accumulating organisms needs the cooperation of anaerobic treatment and aerobic treatment to remove total nitrogen, ammonia nitrogen and total phosphorus; due to the high power consumption of aeration, nitrification liquid and sludge reflux in aerobic treatment, the energy consumption accounts for about 70% of the total energy consumption of sewage treatment, which not only increases the operation cost of the sewage treatment plant, but also causes additional burden to the environment.

[0003] In order to reduce energy consumption and cost, the sewage treatment industry has carried out various improved and reduced aerobic treatment technology development; among them, UASB (upflow anaerobic sludge bed) is a kind of efficient anaerobic biological treatment technology, mainly used for treating high concentration organic wastewater, by forming a dense granular sludge layer in the reactor, the organic matter in the sewage is decomposed into methane and carbon dioxide and other gases under anaerobic conditions, so as to realize the removal of pollutants; but the existing UASB cannot remove nitrogen and phosphorus independently, and needs to be combined with aerobic process to complete the removal of nitrogen and phosphorus. SUMMARY

[0004] The utility model aims at providing sewage treatment device based on UASB process, and the technical problems to be solved are how to realize UASB independent denitrification and phosphorus removal.

[0005] The utility model realizes by the following technical schemes:

[0006] The sewage treatment device based on UASB process, including the jar body, the reaction zone, the electro-biological treatment zone and the sedimentation zone are sequentially arranged from the bottom to the top of the jar body, and the reaction zone and the sedimentation zone are communicated through the electro-biological treatment zone;The reaction zone is provided with a granular sludge bed;The electro-biological treatment zone is provided with a first electrode and a second electrode, and the first electrode and the second electrode are connected with a variable frequency power supply through wires;The variable frequency power supply periodically reverses;

[0007] The bottom of the jar body is provided with a water inlet pipe, and the water inlet pipe is communicated with the reaction zone;The top of the jar body is provided with a water outlet pipe, and the water outlet pipe is communicated with the sedimentation zone.

[0008] The granular sludge bed is composed of highly condensed anaerobic microorganisms, nitrifying bacteria, nitrosifying bacteria, phosphorus accumulating bacteria and anaerobic ammonia oxidation bacteria, and the microorganisms decompose organic matters under anaerobic conditions and convert them into biogas and other products. An alternating current electric field is generated by the first electrode, the second electrode and the variable frequency power supply. In the electro-biological treatment zone, the electric field promotes the denitrification and phosphorus removal, and the denitrifying bacteria reduce nitrate to nitrogen gas using organic matter as an electron donor, thereby achieving denitrification. Meanwhile, the bacteria with phosphorus removal function absorb and release phosphorus under the action of the electric field, thereby achieving phosphorus removal. The granular sludge bed has no physical position division of anode and cathode zones in the alternating current electric field range, and the anode and cathode zones are rapidly switched. After domestication, different microorganisms can complete the required electron gain and loss process in the entire alternating current electric field range, solving the mass transfer problem of different functional bacteria groups and improving the wastewater treatment efficiency. The nitrifying bacteria, nitrosifying bacteria, phosphorus accumulating bacteria and anaerobic ammonia oxidation bacteria can perform normal functional metabolism under anaerobic conditions through electro-biological technology, and complete the removal of nitrogen and phosphorus.

[0009] Further, the precipitation zone is provided with a three-phase separator, and the three-phase separator comprises a gas collecting hood, and an air inlet of the gas collecting hood faces the electro-biological treatment zone; and a first gas pipe is connected to an air outlet of the gas collecting hood.

[0010] The biogas (gas), sludge (solid) and treated water (liquid) are separated by the three-phase separator, and the microorganisms mainly decompose organic matter in the reaction zone and the electro-biological treatment zone to produce biogas. The air inlet of the gas collecting hood is arranged to face the electro-biological treatment zone, so that the biogas can be more effectively collected. The biogas collected by the gas collecting hood is led out through the first gas pipe and used for energy recovery or other purposes.

[0011] Further, the three-phase separator further comprises a baffle, and the baffle is arranged below the gas collecting hood, and a gap is left between the baffle and the gas collecting hood.

[0012] The treated water flows from the gap between the baffle and the gas collecting hood to the water outlet pipe, and the water flow path is optimized. The baffle promotes the reflux of part of the sludge particles from the precipitation zone to the granular sludge bed, which helps to maintain the concentration and activity of the granular sludge bed and is crucial for achieving efficient organic matter degradation and denitrification and phosphorus removal.

[0013] Further, one end of the baffle is connected to the inner wall of the tank body, and the other end is connected to the first electrode.

[0014] The included angle between the baffle and the inner wall of the tank body ranges from 0° to 90°.

[0015] The inclination angle of the baffle helps to optimize the water flow path and sludge distribution. When the included angle between the baffle and the inner wall of the tank is small, most of the sewage flows to the gas hood, and the sludge particles are settled by gravity and return to the reaction zone due to the blockage of the tank top; when the included angle is large, the baffle acts more like a barrier, part of the sewage flows to the bottom of the baffle, and part of the sewage flows to the gas hood, and the sludge particles are blocked by the baffle and settled by gravity and return to the reaction zone.

[0016] Further, the baffle, the tank and the first electrode form a gas collection cavity, and the tank is provided with a second gas pipe which communicates with the gas collection cavity.

[0017] Biogas will naturally rise due to density difference after generation. In the gas collection cavity enclosed by the baffle, the tank and the first electrode, the biogas is led out through the second gas pipe, reducing the escape and loss of gas.

[0018] Further, the tank is provided with a sludge discharge pipe which extends to the bottom of the reaction zone.

[0019] The settled sludge is discharged through the sludge discharge pipe to avoid sludge accumulation.

[0020] Further, the tank is provided with an override pipe which communicates with the reaction zone, and the override pipe is used to transport the bacterial population to the reaction zone.

[0021] The override pipe allows the bacterial population to be directly transported from the outside or other treatment units to the reaction zone, maintaining the stability and activity of the microbial community in the reaction zone. When dealing with high concentration, difficult-to-degrade organic matter or facing water quality fluctuations, the system performance can be quickly restored by supplementing specific bacterial populations through the override pipe, improving the treatment efficiency.

[0022] Further, a water distributor is arranged directly below the second electrode, and the water distributor is used to uniformly distribute the sewage.

[0023] Uniformly distributed sewage can ensure that the microbial community inside the reactor is fully supplied with nutrients, thereby improving the degradation efficiency of organic matter and the denitrification and phosphorus removal effect; avoiding the problem of imbalance of the microbial community caused by uneven water flow, thereby enhancing the stability and reliability of the device.

[0024] Further, the variable frequency power supply is connected to an isolation transformer.

[0025] The isolation transformer ensures the safety of electricity use and avoids the formation of electric leakage between the electrode and the ground.

[0026] Further, the frequency range of the variable frequency power supply is [0.1, 1000] Hz.

[0027] The frequency of the variable frequency power supply has a direct influence on the abundance of each bacterial group in the electro-biological method, and also influences the corrosion speed of the electrode, and the frequency is preferably 0.25-25 Hz.

[0028] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0029] The granular sludge bed is composed of granular sludge composed of highly condensed anaerobic microorganisms, nitrifying bacterial groups, nitrosifying bacterial groups, phosphorus accumulating bacterial groups and anaerobic ammonia oxidation bacterial groups, the microorganisms decompose organic matters under anaerobic conditions and convert the organic matters into products such as biogas, an alternating current electric field is generated through the first electrode, the second electrode and the variable frequency power supply, in the electro-biological treatment area, the electric field promotes the denitrification and phosphorus removal, the denitrifying bacteria reduce nitrate into nitrogen gas by using organic matters as electron donors, so that nitrogen removal is realized, and meanwhile, the bacteria with phosphorus removal function absorb and release phosphorus under the action of the electric field, so that phosphorus removal is realized. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical scheme of the exemplary embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiments, it should be understood that the following drawings only show some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for the ordinary skilled person in the art, under the premise of not paying the creative labor, other related drawings can also be obtained according to these drawings.In the drawings:

[0031] Figure 1 It is the structural schematic diagram of the sewage treatment device.

[0032] Markings in the drawings and corresponding names of parts:

[0033] 1, tank body;11, reaction zone;12, electro-biological treatment area;13, sedimentation zone;14, gas collection chamber;2, three-phase separator;21, baffle;22, gas collection hood;31, water outlet pipe;32, water inlet pipe;33, sludge discharge pipe;34, bypass pipe;35, first gas pipe;36, second gas pipe;4, granular sludge bed;5, variable frequency power supply;6, isolation transformer;71, first electrode;72, second electrode;73, water distributor. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the following will be further detailed to the utility model by combining with the embodiments and the drawings, the illustrative embodiments of the utility model and the explanation thereof are only used to explain the utility model, and should not be regarded as the limitation to the utility model.

[0035] First embodiment:

[0036] Combined Figure 1, the sewage treatment device based on UASB process, including tank body 1, reaction zone 11, electro-biological treatment zone 12 and sedimentation zone 13 are sequentially arranged from the bottom to the top of the tank body 1, and the reaction zone 11 and the sedimentation zone 13 are communicated through the electro-biological treatment zone 12;The reaction zone 11 is provided with a granular sludge bed 4;The electro-biological treatment zone 12 is provided with a first electrode 71 and a second electrode 72, and the first electrode 71 and the second electrode 72 are connected through a wire to a variable frequency power supply 5 (Siemens Sinamics G120 can be used);The variable frequency power supply 5 periodically commutates;

[0037] The bottom of the tank body 1 is provided with a water inlet pipe 32, and the water inlet pipe 32 is communicated with the reaction zone 11;The top of the tank body 1 is provided with a water outlet pipe 31, and the water outlet pipe 31 is communicated with the sedimentation zone 13. The first electrode 71 and the second electrode 72 are 10mm*10mm stainless steel mesh, which can also be made of aluminum or conductive carbon material. In use, the current density can be 100-5000mA / m2, preferably 420mA / m2, and the voltage between electrodes can be 0.02-2.4V / cm, preferably 0.2V / cm.

[0038] The granular sludge bed 4 is composed of highly condensed anaerobic microorganisms, nitrifying bacteria, nitrosifying bacteria, phosphorus accumulating bacteria and anaerobic ammonia oxidation bacteria, and the microorganisms decompose organic matter under anaerobic conditions and convert it into products such as biogas. An alternating current field is generated by the first electrode 71, the second electrode 72 and the variable frequency power supply 5;In the electro-biological treatment zone 12, the electric field promotes the denitrification and phosphorus removal processes, and the denitrifying bacteria use organic matter as an electron donor to reduce nitrate to nitrogen, thereby achieving denitrification;At the same time, the bacteria with phosphorus removal function absorb and release phosphorus under the action of the electric field, thereby achieving phosphorus removal. The granular sludge has good settling performance and can maintain a high biomass in the tank body 1;The granular sludge bed 4 has no physical location division of anode and cathode regions in the alternating current field range, and the anode and cathode regions are rapidly converted, and the microorganisms are domesticated, so that different microorganisms can complete the required electron gain and loss process in the entire alternating current field range, solving the mass transfer problem of different functional bacterial groups metabolism and improving the sewage treatment efficiency;And through the electro-biological technology, the nitrifying bacteria, nitrosifying bacteria, phosphorus accumulating bacteria and anaerobic ammonia oxidation bacteria can perform normal functional metabolism under anaerobic conditions to remove nitrogen and phosphorus.

[0039] Second embodiment:

[0040] On the basis of the first embodiment, the precipitation zone 13 is provided with a three-phase separator 2 (which can adopt the joint environment JLH-SXFS-01), the three-phase separator 2 comprises a gas collecting hood 22 and a baffle 21, the gas suction port of the gas collecting hood 22 is directed towards the electro-biological treatment zone 12; the gas exhaust port of the gas collecting hood 22 is connected with a first gas pipe 35; the baffle 21 is arranged below the gas collecting hood 22, and a gap is left between the baffle 21 and the gas collecting hood 22; one end of the baffle 21 is connected with the inner wall of the tank body 1, and the other end is connected with the first electrode 71; the included angle between the baffle 21 and the inner wall of the tank body 1 ranges from 40°; the baffle 21, the tank body 1 and the first electrode 71 enclose a gas collecting cavity 14, and the tank body 1 is provided with a second gas pipe 36 which communicates with the gas collecting cavity 14.

[0041] The biogas (gas), sludge (solid) and treated water (liquid) are separated by the three-phase separator 2, the microorganisms mainly decompose the organic matters in the reaction zone 11 and the electro-biological treatment zone 12 to produce the biogas, and the gas suction port of the gas collecting hood 22 is directed towards the electro-biological treatment zone 12 to more effectively collect the biogas (main components are CH4 and CO2); the biogas collected by the gas collecting hood 22 is led out through the first gas pipe 35 and used for energy recovery or other purposes, such as power generation, heating, etc. The treated water flows from the gap between the baffle 21 and the gas collecting hood 22 to the water outlet pipe 31, and the baffle 21 promotes the reflux of part of the sludge particles from the precipitation zone 13 to the granular sludge bed 4, which helps to maintain the concentration and activity of the granular sludge bed 4 and is crucial for realizing high-efficiency organic matter degradation and denitrification and phosphorus removal.

[0042] The inclination angle of the baffle 21 helps to optimize the water flow path and sludge distribution. The baffle 21 inclined by 40° acts as a barrier, part of the sewage flows to the bottom of the baffle 21, and part of the sewage flows to the gas collecting hood 22, the baffle 21 blocks the upward movement of the sludge particles, the sludge particles are subjected to gravity to realize sedimentation and reflux to the reaction zone 11.

[0043] After the biogas is produced, it naturally rises due to the density difference, is collected by the gas collecting cavity 14 and the gas collecting hood 22, and is led out through the first gas pipe 35 and the second gas pipe 36.

[0044] Third embodiment:

[0045] On the basis of any of the above embodiments, the tank body 1 is provided with a sludge discharge pipe 33 which extends to the bottom of the reaction zone 11. A sewage pump can be arranged as needed during use to pump out the sludge accumulated on the bottom wall of the reaction zone 11, so as to avoid sludge accumulation.

[0046] Fourth embodiment:

[0047] On the basis of any of the above embodiments, the tank body 1 is provided with an override pipe 34 which communicates with the reaction zone 11, and the override pipe 34 is used to transport the bacterial population to the reaction zone 11.

[0048] The bypass pipe 34 allows direct delivery of bacterial populations from external or other treatment units to the reaction zone 11, maintaining the stability and activity of the microbial community within the reaction zone 11. In the treatment of high concentrations of refractory organic matter or in the face of water quality fluctuations, the system performance can be quickly restored by supplementing specific bacterial populations through the bypass pipe 34, improving treatment efficiency.

[0049] The bypass pipe 34 makes the treatment process more flexible. For example, during the start-up phase or when treating special water quality, a bacterial population with strong adaptability and high degradation efficiency can be quickly introduced through the bypass pipe 34 to accelerate the start-up and stable operation of the reactor; in addition, when the internal bacterial population of the reactor is imbalanced, the bacterial population can also be adjusted through the bypass pipe 34 to restore system performance.

[0050] By delivering bacterial populations through the bypass pipe 34, sludge waste can be reduced. In traditional treatment processes, when the internal bacterial population of the reactor is imbalanced or the treatment efficiency is reduced, a large amount of sludge may need to be discharged and re-inoculated. The design of the bypass pipe 34 allows the internal bacterial population of the reactor to be maintained while only supplementing the necessary bacterial population, thereby reducing sludge waste and treatment costs.

[0051] Fifth embodiment:

[0052] On the basis of any of the above embodiments, a water distributor 73 (which can use Long Life Environmental Protection BS-32) is provided directly below the second electrode 72, and the water distributor 73 is used to uniformly distribute sewage.

[0053] Uniformly distributed sewage can ensure that the microbial community inside the tank 1 is adequately supplied with nutrients, thereby improving the degradation efficiency of organic matter and the nitrogen and phosphorus removal effect; avoiding the problem of microbial community imbalance caused by uneven water flow, thereby enhancing the stability and reliability of the device.

[0054] Sixth embodiment:

[0055] On the basis of any of the above embodiments, the frequency range of the frequency conversion power supply 5 is [0.1, 1000] Hz.

[0056] The use of the isolation transformer 6 ensures electrical safety and prevents electrode-to-ground leakage. The frequency of the frequency conversion power supply 5 directly affects the abundance of each bacterial population in the electrobiology method, and also affects the corrosion rate of the electrode, with a preferred range of 0.25-25 Hz.

[0057] The use of the sewage treatment device: after the sludge domestication is completed, the frequency power supply 5 is opened through the isolation transformer 6, the output alternating current, the voltage of the first electrode 71 and the second electrode 72 is set to 48V, the frequency is 8Hz, the first electrode 71 and the second electrode 72 form a loop, the current is 5-6 ampere, the hydraulic retention time (HRT) is usually 1 day. The temperature range is 35-38℃ (mesophilic fermentation), and the pH value range is 6.5-7.5.

[0058] In addition, the influent water quality can be sampled and analyzed: Cod 600mg / L, TN 30mg / L, NH4-N 30mg / L, TP 2mg / L; the effluent water quality is sampled and analyzed: Cod 46.5mg / L, TN 10.3mg / L, NH4-N 7.9mg / L, TP 0.2mg / L.

[0059] The above-described specific embodiments have further detailed the purposes, technical solutions and beneficial effects of the utility model, and it should be understood that the above-described is only a specific embodiment of the utility model and is not used to limit the protection scope of the utility model, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A wastewater treatment apparatus based on UASB process, characterized in that, The application relates to a sewage treatment device, which comprises a tank body (1), a reaction zone (11), an electro-biological treatment zone (12) and a sedimentation zone (13) arranged in sequence from the bottom to the top of the tank body (1), and the reaction zone (11) and the sedimentation zone (13) are communicated through the electro-biological treatment zone (12); the reaction zone (11) is provided with a granular sludge bed (4); the electro-biological treatment zone (12) is provided with a first electrode (71) and a second electrode (72), the first electrode (71) and the second electrode (72) are connected with a variable-frequency power supply (5) through wires; the variable-frequency power supply (5) periodically reverses direction. The bottom of the tank body (1) is provided with a water inlet pipe (32) communicated with the reaction zone (11); the top of the tank body (1) is provided with a water outlet pipe (31) communicated with the sedimentation zone (13).

2. The sewage treatment device according to claim 1, characterized in that, The sedimentation zone (13) is provided with a three-phase separator (2), the three-phase separator (2) comprises a gas collecting hood (22), the air inlet of the gas collecting hood (22) faces the electro-biological treatment zone (12); the air outlet of the gas collecting hood (22) is connected with a first air pipe (35).

3. The sewage treatment device according to claim 2, characterized in that The three-phase separator (2) further comprises a baffle (21), the baffle (21) is arranged below the gas collecting hood (22), and a gap is left between the baffle (21) and the gas collecting hood (22).

4. The sewage treatment device according to claim 3, characterized in that One end of the baffle (21) is connected with the inner wall of the tank body (1), and the other end is connected with the first electrode (71). The included angle between the baffle (21) and the inner wall of the tank body (1) ranges from 0 to 90 degrees.

5. The sewage treatment device of claim 4, wherein, The baffle (21), the tank body (1) and the first electrode (71) form a gas collecting cavity (14), and the tank body (1) is provided with a second air pipe (36) communicated with the gas collecting cavity (14).

6. The sewage treatment device of claim 1, wherein The tank body (1) is provided with a sludge discharge pipe (33) extending to the bottom of the reaction zone (11).

7. The sewage treatment device of claim 6, wherein The tank body (1) is provided with an override pipe (34) communicated with the reaction zone (11), and the override pipe (34) is used for conveying a bacterial population to the reaction zone (11).

8. The sewage treatment device of claim 1, wherein, A water distributor (73) is arranged directly below the second electrode (72), and the water distributor (73) is used for uniformly distributing sewage.

9. The sewage treatment device of claim 1, wherein, The variable-frequency power supply (5) is connected with an isolation transformer (6).

10. The sewage treatment device of claim 1, wherein The frequency range of the variable-frequency power supply (5) is [0.1, 1000] Hz.

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