Alternating current biological sewage treatment device

Abstract

The utility model provides an alternating current biological sewage treatment device, which relates to microbial sewage treatment and comprises an electric biological treatment tank, the electric biological treatment tank is provided with a plurality of first partition plates, and the electric biological treatment tank is divided into a plurality of electric biological branch tanks by the first partition plates; a central electrode and a peripheral electrode are arranged in each electrical biological sub-tank and are connected with a variable-frequency power supply through wires; and periodically reversing the variable-frequency power supply. Through periodic reversing of the variable-frequency power supply, the central electrode and the peripheral electrode can be anodes or cathodes, so that the electrodes are prevented from being continuously corroded, and the corrosion speed of the anodes is slowed down; due to periodic change of the polarity of the electrode, discharge and deposition of charged sol clusters and suspended solids on the surface of the electrode become unstable, the charged sol clusters and the suspended solids may be deposited on the electrode in one period, but are released or redistributed due to change of the polarity of the electrode in the next period, and formation of scaling is reduced.

Description

Technical Field

[0001] This utility model relates to microbial wastewater treatment, specifically to an alternating current biological wastewater treatment device. Background Technology

[0002] Biological wastewater treatment is one of the important technologies in the field of environmental protection. It mainly uses aerobic treatment, anaerobic treatment, and combinations of both to form various efficient wastewater treatment processes. While anaerobic and aerobic treatments can remove reducing substances (COD) from wastewater, they both have problems. The phosphorus release and uptake processes of polyphosphate-accumulating bacteria require the cooperation of anaerobic and aerobic treatments to remove total nitrogen, ammonia nitrogen, and total phosphorus. Because aerobic treatment has high energy consumption for aeration, nitrification liquor, and sludge return, it accounts for about 70% of the total energy consumption of wastewater treatment, which not only increases the operating costs of wastewater treatment plants but also places an additional burden on the environment.

[0003] To reduce energy consumption and costs, the wastewater treatment industry has developed various technologies to improve and reduce aerobic treatment. Among them, anaerobic ammonia oxidation is one of the most researched and cutting-edge technologies at home and abroad. Patent document CN117383699A discloses a continuous current electro-anaerobic ammonia oxidation denitrification system. Although it reduces the need for aerobic treatment, the use of DC-assisted electrobiological treatment makes the anode prone to corrosion. Charged aerosols and suspended solids in wastewater are prone to discharge and scale on the electrode surface, leading to electrode failure. Utility Model Content

[0004] The purpose of this invention is to provide an alternating current biological wastewater treatment device, and the technical problem to be solved is how to reduce the rate of electrode corrosion and scaling.

[0005] This utility model is achieved through the following technical solution:

[0006] An alternating current electrobiological wastewater treatment device includes an electrobiological treatment tank, wherein the electrobiological treatment tank is provided with a plurality of first partitions, which divide the electrobiological treatment tank into multiple electrobiological sub-tanks.

[0007] A central electrode and peripheral electrodes are arranged in each of the above-mentioned electrobiological sub-pools. The central electrode and peripheral electrode are connected to a variable frequency power supply through wires. The variable frequency power supply is periodically reversed.

[0008] The aforementioned variable frequency power supply provides electron acceptors for nitrifying bacteria, nitrite-oxidizing bacteria, anaerobic ammonia-oxidizing bacteria, and polyphosphate-accumulating bacteria, and electron donors for denitrifying bacteria, polyphosphate-accumulating bacteria, and phosphorus-removing bacteria, thus forming an anaerobic wastewater treatment process and reducing the need for aerobic treatment. Through the periodic reversal of the aforementioned variable frequency power supply, the central electrode and the peripheral electrode can be either anodes or cathodes, avoiding continuous corrosion of the electrodes and thus slowing down the rate of anode corrosion. Due to the periodic change in electrode polarity, the discharge and deposition of charged aerosols and suspended matter on the electrode surface become unstable. They may be deposited on the electrode in one cycle, but be released or redistributed in the next cycle due to the change in electrode polarity. This unstable deposition and release process reduces the formation of scale.

[0009] Furthermore, the aforementioned electrobiological treatment tank is equipped with a stirrer.

[0010] The aforementioned agitator is used to stir the acclimated activated sludge, ensuring that charged aerosols, suspended solids, and microorganisms in the wastewater are evenly distributed within the electrobiological treatment tank. Stirring also prevents charged aerosols and suspended solids from remaining on the electrode surface for extended periods and depositing, thus helping to break up existing sediment layers and prevent further solidification and accumulation.

[0011] Furthermore, the aforementioned electrobiological treatment tank is equipped with elastic packing material.

[0012] Microorganisms attach to the elastic packing material, forming a biofilm that promotes interaction among microorganisms, enhances biological activity, and thus improves pollutant removal rates. The elastic packing material moves with the water flow under the action of the agitator, facilitating more thorough contact and reaction between charged aerosols, suspended solids, and microorganisms, thereby improving treatment efficiency. Although the elastic packing material does not directly act on the electrodes, it indirectly reduces electrode corrosion and scaling by improving water flow and enhancing biological treatment effects; the biofilm formed by microorganisms on the packing material can adsorb and degrade some pollutants, reducing the deposition of these substances on the electrode surface.

[0013] The variable frequency power supply reduces electrode corrosion and scaling through periodic commutation, the agitator improves treatment efficiency by enhancing mixing, and the elastic packing further enhances the treatment effect by providing a surface for bio-attachment and enhancing biological activity. This not only improves the quality of wastewater treatment but also reduces operating and maintenance costs.

[0014] Furthermore, the wastewater treatment device also includes a sedimentation tank and a sludge digestion tank. The sedimentation tank is equipped with a sludge lift pump, and the sludge lift pump is connected to a sludge conveying pipe. The sedimentation tank and the sludge digestion tank are connected through the sludge conveying pipe. The sediment in the sedimentation tank is transported to the sludge digestion tank through the sludge lift pump and the sludge conveying pipe.

[0015] Solid particles (such as suspended solids, colloids, and some microorganisms) settle to the bottom of the sedimentation tank due to gravity, which can remove most of the solid particles, reduce the treatment load of subsequent treatment units (such as sludge digestion tanks and filtration tanks), and improve the overall treatment efficiency.

[0016] Furthermore, the sedimentation tank includes a first sedimentation tank and a second sedimentation tank. The first sedimentation tank is separated from the electro-biological treatment tank by a second partition. The second partition is provided with a first overflow port. Water in the first sedimentation tank enters the electro-biological treatment tank through the first overflow port.

[0017] The aforementioned second sedimentation tank is connected to the electrobiological treatment tank via a sewage delivery pipe, and water from the electrobiological treatment tank enters the second sedimentation tank through the sewage delivery pipe.

[0018] The aforementioned first sedimentation tank serves as a pretreatment unit for wastewater before it enters the electrobiological treatment tank. It primarily removes large suspended solids and colloids from the wastewater. These substances settle due to gravity in the sedimentation tank, reducing the pollutant load entering the electrobiological treatment tank. After treatment in the electrobiological treatment tank, the wastewater enters the second sedimentation tank for deep sedimentation, further removing fine suspended solids and bioflocs to improve the effluent quality.

[0019] Furthermore, the wastewater treatment device also includes a filter tank, which is separated from the second sedimentation tank by a third partition. The third partition is provided with a second overflow port, through which water in the second sedimentation tank enters the filter tank.

[0020] The above-mentioned filtration tank removes residual fine suspended solids, colloids, microbial flocs, etc. from the second sedimentation tank, thereby further improving the quality of the effluent.

[0021] Furthermore, the wastewater treatment device also includes a clear water tank, which is connected to the filter tank via a clear water delivery pipe, and water from the filter tank enters the clear water tank through the clear water delivery pipe.

[0022] Furthermore, the frequency range of the aforementioned variable frequency power supply is 0.1 to 1000 Hz.

[0023] The power supply frequency has a direct impact on the abundance of various bacterial communities in the electrobiological method, and also affects the corrosion rate of the electrodes.

[0024] Furthermore, the aforementioned frequency converter is connected to the controller via an isolation transformer.

[0025] The aforementioned isolation transformer ensures electrical safety and prevents leakage between the electrodes and the ground.

[0026] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0027] The aforementioned variable frequency power supply provides electron acceptors for nitrifying bacteria, nitrite-oxidizing bacteria, anaerobic ammonia-oxidizing bacteria, and polyphosphate-accumulating bacteria, and electron donors for denitrifying bacteria, polyphosphate-accumulating bacteria, and phosphorus-removing bacteria, thus forming an anaerobic wastewater treatment process and reducing the need for aerobic treatment. Through the periodic reversal of the aforementioned variable frequency power supply, the central electrode and the peripheral electrode can be either anodes or cathodes, avoiding continuous corrosion of the electrodes and thus slowing down the rate of anode corrosion. Due to the periodic change in electrode polarity, the discharge and deposition of charged aerosols and suspended matter on the electrode surface become unstable. They may be deposited on the electrode in one cycle, but be released or redistributed in the next cycle due to the change in electrode polarity. This unstable deposition and release process reduces the formation of scale. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the exemplary embodiments of this utility model, the drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0029] Figure 1 This is a simplified diagram of a wastewater treatment plant;

[0030] Figure 2 This is a top view of the electrobiological treatment tank.

[0031] The attached diagram shows the markings and corresponding component names:

[0032] 1. Sludge digestion tank; 21. Sludge lift pump; 22. First settling tank; 23. Second settling tank; 3. Electrobiological treatment tank; 31. Central electrode; 32. Peripheral electrode; 33. Agitator; 34. Elastic packing material; 4. Filter tank; 5. Equipment room; 51. Variable frequency power supply; 52. Isolation transformer; 53. Controller; 6. Clear water tank; 71. Sludge conveying pipe; 72. Wastewater conveying pipe; 73. Clear water conveying pipe. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0034] First embodiment:

[0035] Combination Figure 1 and Figure 2An alternating current electrobiological wastewater treatment device includes a sedimentation tank, an electrobiological treatment tank 3, a sludge digestion tank 1, a filtration tank 4, a clear water tank 6, and an equipment room 5. The sedimentation tank includes a first sedimentation tank 22 and a second sedimentation tank 23. The wastewater flow direction during wastewater treatment is as follows: wastewater enters the first sedimentation tank 22 for sedimentation, the settled wastewater enters the electrobiological treatment tank 3, the wastewater flowing out of the electrobiological treatment tank 3 enters the second sedimentation tank 23 for sedimentation, the settled wastewater enters the filtration tank 4, and the filtered water enters the clear water tank 6. The sludge flow direction during wastewater treatment is as follows: the sediment from the first sedimentation tank 22 and the second sedimentation tank 23 enters the sludge digestion tank 1.

[0036] The electrobiological treatment tank 3 is provided with several first partitions (not shown in the figure), which divide the electrobiological treatment tank 3 into multiple electrobiological sub-tanks.

[0037] A central electrode 31 and peripheral electrodes 32 are arranged in each of the above-mentioned electrobiological sub-cells. The central electrode 31 and peripheral electrodes 32 are connected to the frequency converter 51 of the equipment room 5 (which can be a BC70 series touch-sensitive frequency converter 51 or a Toshiba MG100J2YS50) via wires; the frequency converter 51 is periodically switched. The peripheral electrodes 32 can be made of stainless steel mesh, and the central electrode 31 can be made of stainless steel tube. The electrode materials can be stainless steel, aluminum, or conductive carbon materials. The current density is 100-5000 mA / m², preferably 420 mA / m², and the voltage between electrodes is 0.02-2.4 V / cm, preferably 0.2 V / cm.

[0038] By periodically switching the frequency converter 51, the center electrode 31 and the peripheral electrode 32 can be either anodes or cathodes, thus avoiding continuous corrosion of the electrodes and slowing down the rate of anode corrosion. Due to the periodic change in electrode polarity, the discharge and deposition of charged aerosols and suspended matter on the electrode surface become unstable. They may be deposited on the electrode in one cycle, but be released or redistributed in the next cycle due to the change in electrode polarity. This unstable deposition and release process reduces the formation of scale.

[0039] In a specific embodiment, the frequency range of the aforementioned variable frequency power supply 51 is 0.1 to 1000 Hz, preferably 0.25 to 25 Hz. The aforementioned equipment room 5 also includes an isolation transformer 52 (which may be an SG / SBK series three-phase dry-type isolation transformer 52 or a BK series single-phase isolation transformer 52) and a controller 53 (which may be a microcontroller, PLC, computer, etc.). The aforementioned variable frequency power supply 51 is connected to the controller 53 through the isolation transformer 52.

[0040] The power supply frequency directly affects the abundance of various bacterial communities in the electrobiological method, and also affects the corrosion rate of the electrodes. The aforementioned isolation transformer 52 ensures electrical safety and prevents leakage between the electrodes and the ground.

[0041] Second embodiment:

[0042] Based on the first embodiment, the electrobiological treatment tank 3 is provided with a stirrer 33, which can be a push-flow stirrer 33, with model examples: QJB22 / 12-620 / 3-480 or QJB7.5 / 12-620 / 3-480S.

[0043] The stirrer 33 is used to stir the acclimated activated sludge to ensure that the charged aerosols, suspended solids and microorganisms in the wastewater are evenly distributed in the electrobiological treatment tank 3. Stirring prevents the charged aerosols and suspended solids from staying on the electrode surface for a long time and depositing, which helps to break up the existing sediment layer and prevent it from further solidifying and accumulating.

[0044] Third embodiment:

[0045] Based on the second embodiment, the electrobiological treatment tank 3 is provided with elastic packing material 34.

[0046] Microorganisms attach to the elastic packing material 34 to form a biofilm, promoting interactions among microorganisms, enhancing biological activity, and thus improving the removal rate of pollutants. The elastic packing material 34 moves with the water flow under the action of the agitator 33, facilitating more thorough contact and reaction between charged aerosols, suspended solids, and microorganisms, thereby improving treatment efficiency. Although the elastic packing material 34 does not directly act on the electrodes, it indirectly reduces electrode corrosion and scaling by improving water flow and enhancing biological treatment effects; the biofilm formed by microorganisms on the packing material can adsorb and degrade some pollutants, reducing the deposition of these substances on the electrode surface.

[0047] The variable frequency power supply 51 reduces electrode corrosion and scaling through periodic reversal, the agitator 33 improves treatment efficiency by enhancing mixing, and the elastic packing 34 further enhances the treatment effect by providing a surface for biological attachment and enhancing biological activity. This not only improves the quality of wastewater treatment but also reduces operating and maintenance costs.

[0048] The device eliminates the need for aerobic treatment and aeration equipment, and adopts a flow mixer 33, which reduces the energy consumption of wastewater treatment.

[0049] Due to the periodic commutation of the variable frequency power supply 51, within the AC electric field range, the biofilm hanging on the elastic packing 34, the activated sludge distributed in the sewage, and the anode and cathode areas without physical separation, the anode and cathode areas rapidly switch, and the microorganisms are domesticated and selected at different frequencies. During respiration, within the entire AC electric field range, different microorganisms can complete the required electron gain and loss processes, solving the mass transfer problem of metabolism of different functional bacterial groups and improving sewage treatment efficiency.

[0050] Fourth embodiment:

[0051] Based on any of the above embodiments, the sedimentation tank is equipped with a sludge lift pump 21 (which can be a WQ series submersible sewage pump, a ZLB type vertical axial flow pump, or a WL type vertical sewage pump; specific models can be WQ15-20-2.2, WQ20-15-2.2, or WQ40-13-2.2). The sludge lift pump 21 is connected to a sludge conveying pipe 71, and the sedimentation tank and the sludge digestion tank 1 are connected through the sludge conveying pipe 71. The sludge in the sedimentation tank is conveyed to the sludge digestion tank 1 through the sludge lift pump 21 and the sludge conveying pipe 71.

[0052] Solid particles (such as suspended solids, colloids, and some microorganisms) settle to the bottom of the sedimentation tank due to gravity, which can remove most of the solid particles, reduce the treatment load of subsequent treatment units (such as sludge digestion tank 1, filtration tank 4, etc.), and improve the overall treatment efficiency.

[0053] In a specific embodiment, the first sedimentation tank 22 and the electro-biological treatment tank 3 are separated by a second partition (not shown in the figure). The second partition is provided with a first overflow port, and the water in the first sedimentation tank 22 enters the electro-biological treatment tank 3 through the first overflow port.

[0054] The second sedimentation tank 23 is connected to the electrobiological treatment tank 3 via a sewage delivery pipe 72, and the water in the electrobiological treatment tank 3 enters the second sedimentation tank 23 through the sewage delivery pipe 72.

[0055] The first sedimentation tank 22, as a pretreatment unit for wastewater before it enters the electrobiological treatment tank 3, is mainly used to remove large particulate matter, colloids, and other substances from the wastewater. These substances settle in the sedimentation tank due to gravity, reducing the pollutant load entering the electrobiological treatment tank 3. After treatment in the electrobiological treatment tank 3, the wastewater enters the second sedimentation tank 23 for deep sedimentation, further removing fine suspended solids, biological flocs, and other substances to improve the effluent quality.

[0056] When the water level in the first sedimentation tank 22 reaches the set height, the sewage will flow into the electro-biological treatment tank 3 through the first overflow outlet. During the treatment process, the water in the electro-biological treatment tank 3 is sent to the second sedimentation tank 23 through the sewage conveying pipe 72 for sedimentation. The treated sewage is then further sedimented to improve the quality of the effluent.

[0057] Fifth embodiment:

[0058] Based on the fourth embodiment, the filter tank 4 and the second sedimentation tank 23 are separated by a third partition. The third partition is provided with a second overflow port, and the water in the second sedimentation tank 23 enters the filter tank 4 through the second overflow port.

[0059] The aforementioned filtration tank 4 removes residual fine suspended solids, colloids, and microbial flocs from the second settling tank 23, further improving the effluent quality. The filter medium can be one or more of sand, activated carbon, ceramic filter media, etc. When the water level in the second settling tank 23 reaches a set height, the wastewater will flow into the filtration tank 4 through the second overflow port, ensuring the continuity and stability of wastewater treatment while preventing wastewater overflow due to excessively high water levels.

[0060] Sixth embodiment:

[0061] Based on any of the above embodiments, the clear water tank 6 and the filter tank 4 are connected by a clear water delivery pipe 73, and the water in the filter tank 4 enters the clear water tank 6 through the clear water delivery pipe 73. Disinfectant can also be added to the clear water tank 6 to disinfect the clear water.

[0062] The aforementioned clear water tank 6 is used to store the clear water treated by the filtration tank 4. The clear water tank 6 can serve as an emergency water source, providing temporary water supply when the sewage treatment plant malfunctions or is under maintenance.

[0063] One possible application scenario is that, after sludge acclimation is completed, the control parameters of the controller 53 are set as follows: the voltage between the central electrode 31 and the peripheral electrode 32 is 26V, the frequency of the variable frequency power supply 51 is 0.25Hz, the electrode circuit is 6-9 amperes, the hydraulic retention time (HRT) is 18 hours, the effluent temperature range is 10-32℃, and the pH value range is 6.5-9.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. An alternating current biological wastewater treatment device, characterized in that, It includes an electrobiological treatment tank (3), which is provided with several first partitions to divide the electrobiological treatment tank (3) into multiple electrobiological sub-tanks. A central electrode (31) and a peripheral electrode (32) are arranged in each of the electrobiological sub-cells. The central electrode (31) and the peripheral electrode (32) are connected to a variable frequency power supply (51) through wires. The variable frequency power supply (51) is periodically reversed.

2. The sewage treatment device according to claim 1, characterized in that, The electrobiological treatment tank (3) is equipped with a stirrer (33).

3. The sewage treatment device according to claim 2, characterized in that The electrobiological treatment tank (3) is equipped with elastic packing material (34).

4. The sewage treatment device according to claim 1, characterized by The wastewater treatment device also includes a sedimentation tank and a sludge digestion tank (1). The sedimentation tank is equipped with a sludge lift pump (21), and a sludge conveying pipe (71) is connected to the sludge lift pump (21). The sedimentation tank and the sludge digestion tank (1) are connected through the sludge conveying pipe (71). The sediment in the sedimentation tank is transported to the sludge digestion tank (1) through the sludge lift pump (21) and the sludge conveying pipe (71).

5. The wastewater treatment device according to claim 4, characterized in that, The sedimentation tank includes a first sedimentation tank (22) and a second sedimentation tank (23). The first sedimentation tank (22) is separated from the electro-biological treatment tank (3) by a second partition. The second partition is provided with a first overflow port. Water in the first sedimentation tank (22) enters the electro-biological treatment tank (3) through the first overflow port. The second sedimentation tank (23) is connected to the electrobiological treatment tank (3) through a sewage conveying pipe (72), and the water in the electrobiological treatment tank (3) enters the second sedimentation tank (23) through the sewage conveying pipe (72).

6. The sewage treatment device of claim 5, wherein, The wastewater treatment device also includes a filter tank (4), which is separated from the second sedimentation tank (23) by a third partition. The third partition is provided with a second overflow port, through which water in the second sedimentation tank (23) enters the filter tank (4).

7. The sewage treatment device of claim 6, wherein The wastewater treatment device also includes a clear water tank (6), which is connected to the filter tank (4) via a clear water delivery pipe (73). Water in the filter tank (4) enters the clear water tank (6) through the clear water delivery pipe (73).

8. The wastewater treatment device according to claim 1, characterized in that, The frequency range of the variable frequency power supply (51) is 0.1 to 1000 Hz.

9. The sewage treatment device of claim 1, wherein, The variable frequency power supply (51) is connected to the controller (53) through an isolation transformer (52).

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