Sewage treatment system

Abstract

The utility model discloses a sewage treatment system, which belongs to the technical field of sewage treatment and comprises a sewage inlet sequentially connected with a pretreatment unit, a primary anaerobic tank, a secondary anaerobic tank, an aerobic tank, a post-treatment unit and a water outlet. The primary anaerobic tank is of a sealed structure, a water distribution device and an aeration device are arranged at the bottom, a double-layer bracket is arranged at the middle lower part, a knotted nylon rope is connected between the double-layer bracket, and a water outlet and a sludge inlet are formed in the top of the side surface; under the condition of not increasing physicochemical treatment agents, the water quality is improved, and the device has the characteristic of low treatment cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment, and in particular relates to a sewage treatment system. Background Art

[0002] Generally speaking, sewage treatment plants produce a large amount of sludge and the treatment cost is high. Since the sludge contains microorganisms that degrade organic matter, ammonia oxidizing bacteria, nitrifying bacteria and other microorganisms, some sewage treatment plants recycle the generated sludge and apply it to the treatment process, using the sludge to degrade organic matter and improve water quality, thereby reducing the amount of physicochemical treatment agents and reducing treatment costs. For example, Chinese patent CN 112777844 A provides a

[0003] A microbial enrichment system for degrading difficult-to-degrade organic matter returns the sludge into the system, improves the sludge composition ratio, and increases the proportion of difficult-to-degrade microorganisms and autotrophic microorganisms, which is beneficial to improving the effluent water quality and reducing treatment costs.

[0004] However, when actually treating alkaline sewage, due to the high pH value of the sewage and the high concentration of pollutants in the sewage, when the system in CN 112777844 A is applied for treatment, the anaerobic tank 2 cannot degrade most of the organic matter in the sewage. The reason may be that although the anaerobic tank 2 has added a stirring device to allow the sewage and the sludge to fully contact, the dynamic muddy water environment has an adverse effect on the decomposition of organic matter by microorganisms, and the microorganisms can easily flow with the sewage to the next treatment unit, resulting in the microorganisms being unable to fully degrade the organic matter in the sewage. Therefore, when treating alkaline sewage, the treatment effect is not ideal, and it is necessary to increase the physicochemical treatment agents to reduce the amount of pollutants, which increases the treatment cost. Utility Model Content

[0005] In order to solve the above deficiencies in the prior art, the utility model aims to provide a sewage treatment system. On the basis of adding a sludge circulation system, the structure of the primary anaerobic tank of the key treatment unit is upgraded, so that the microorganisms in the sludge can fully degrade the organic matter in the sewage, and the water quality is improved without adding physicochemical treatment agents, so as to achieve the purpose of reducing treatment costs.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] A sewage treatment system comprises a sewage inlet, which is sequentially connected to a pretreatment unit, a primary anaerobic tank, a secondary anaerobic tank, an aerobic tank, a post-treatment unit and a water outlet;

[0008] The first-level anaerobic tank is a sealed structure with a water distribution device and an aeration device at the bottom, a double-layer bracket at the middle and lower part, knotted nylon ropes connecting the double-layer brackets, and a water outlet and a sludge inlet at the top of the side.

[0009] Wherein, knotted nylon ropes are connected at equal intervals between the double-layer brackets, the nylon ropes are perpendicular to the horizontal plane, there is at least one knot on the nylon rope, and the distance between adjacent knots on the nylon rope is 0.

[0010] As a limitation of the present invention, the double-layer bracket includes an upper bracket and a lower bracket, the upper bracket is a horizontally parallel distributed steel rope, and the lower bracket is symmetrically arranged therewith.

[0011] As a further limitation of the present invention, the steel ropes in the upper bracket are distributed at equal intervals on the same horizontal plane; the area formed by the upper bracket is the same as the area of ​​the horizontal cross section of the primary anaerobic tank.

[0012] As a limitation of the present invention, the secondary anaerobic tank is a sealed structure, with a water distribution device at the bottom, a three-phase separator in the middle, a biogas outlet at the top, and a water outlet at the top of the side;

[0013] An anaerobic lifting tank is arranged between the primary anaerobic tank and the secondary anaerobic tank.

[0014] Among them, the heights of the first-level anaerobic tank and the anaerobic lifting tank are set to decrease successively.

[0015] The anaerobic lift tank is used to collect sewage from the primary anaerobic tank and send it to the secondary anaerobic tank.

[0016] As a limitation of the present invention, the water distribution device comprises at least one water inlet, at least one pipe and at least one water outlet, the water outlet being connected to the water inlet via the pipe;

[0017] The water outlets are evenly distributed at the bottom of the primary anaerobic tank or the secondary anaerobic tank.

[0018] As a further limitation of the present invention, the three-phase separator includes a bracket and at least one V-shaped steel plate;

[0019] The bracket is a mesh surface obtained by welding angle steels. The bracket is parallel to the horizontal plane, and the area formed by the bracket is the same as the area of ​​the horizontal cross section of the secondary anaerobic tank.

[0020] The V-shaped steel plate is obtained by welding the long sides of two rectangular steel plates, and the V-shaped steel plates are placed on the bracket in an inverted V shape with equal intervals.

[0021] As a limitation of the present utility model, the aerobic pool is a sealed structure, an aeration device is arranged at the bottom, and a water outlet and a water inlet are arranged at the top of the side.

[0022] As a limitation of the present invention, the aeration device comprises at least one gas inlet, at least one pipeline and at least one gas outlet, the gas outlet is connected to the gas inlet through the pipeline; the gas inlet is connected to the blower to deliver air;

[0023] The gas outlets are evenly distributed at the bottom of the primary anaerobic tank or aerobic tank.

[0024] As a limitation of the present invention, the pre-treatment unit includes a grid channel, a water collection tank and an accident tank;

[0025] The sewage inlet is connected to the screen channel, the screen channel is connected to the water collection tank, the water collection tank is connected to the primary anaerobic tank and the accident tank, the accident tank is connected to the screen channel, and the screen channel, the water collection tank and the accident tank form a circulation loop.

[0026] As a limitation of the present invention, the post-processing unit includes a secondary sedimentation tank and a metering channel. The secondary sedimentation tank is connected to the primary anaerobic tank through a sludge tank to form a sludge circulation loop.

[0027] The heights of the secondary anaerobic tank, aerobic tank and secondary sedimentation tank are set to decrease successively.

[0028] Due to the adoption of the above technical solution, the utility model has the following beneficial effects compared with the prior art:

[0029] The utility model sewage treatment system is based on adding a sludge circulation system, and upgrades the structure of the key treatment units, the primary anaerobic tank, the secondary anaerobic tank and the aerobic tank, and upgrades the water distribution device of the primary anaerobic tank and the secondary anaerobic tank, changing one water outlet to several water outlets, and evenly distributes the water outlets at the bottom, so that the sewage reaches the water outlet from the bottom through the sludge, so as to ensure that the sewage and the sludge are fully in contact;

[0030] A double-layer bracket is arranged in the middle and lower part of the primary anaerobic tank, and a knotted nylon rope is connected between the double-layer brackets. The knotted nylon rope can absorb various microorganisms in the sludge, and the adsorbed microorganisms can fully degrade organic matter in the sewage. The utility model adopts the knotted nylon rope to increase the microbial adsorption;

[0031] An aeration device is installed at the bottom of the primary anaerobic tank to replenish air and keep the microorganisms in the sludge in the tank active, thereby degrading the organic matter in the sewage.

[0032] The three-phase separator in the secondary anaerobic tank adopts a bracket and a V-shaped steel plate. The V-shaped steel plate is placed on the bracket in an inverted V shape. Such a structure can effectively separate digestion gas, digestion liquid and sludge particles, and enrich microorganisms at the same time, so that anaerobic microorganisms can fully play their role;

[0033] An aeration device is installed at the bottom of the aerobic pool, and the gas inlet is evenly distributed at the bottom, so that the oxygen in the aerobic pool is evenly distributed, ensuring that aerobic microorganisms can obtain sufficient oxygen and maintain activity;

[0034] The utility model upgrades the structure of the primary anaerobic tank, the secondary anaerobic tank and the aerobic tank, so that the microorganisms in the sludge can fully degrade the organic matter in the sewage, which is particularly suitable for alkaline sewage. The water quality is improved without adding physicochemical treatment agents, thereby saving costs.

[0035] The utility model sewage treatment system is suitable for treating alkaline sewage. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention is described in further detail below in conjunction with the accompanying drawings and specific embodiments.

[0037] Figure 1 This is a schematic diagram of a sewage treatment system in an embodiment of the utility model;

[0038] Figure 2 It is a vertical cross-sectional view of a primary anaerobic tank in an embodiment of the utility model;

[0039] Figure 3 It is a schematic diagram of a top view of a double-layer bracket and a knotted nylon rope in an embodiment of the utility model;

[0040] Figure 4 This is a schematic diagram of the top view of the water distribution device and the aeration device in the embodiment of the utility model;

[0041] Figure 5 It is a vertical cross-sectional view of a secondary anaerobic tank in an embodiment of the utility model;

[0042] Figure 6 It is a vertical cross-sectional view of an aerobic pool in an embodiment of the utility model;

[0043] In the figure: 1. water inlet; 2. pipe; 3. water outlet; 4. gas inlet; 5. gas outlet; 6. lower bracket; 7. upper bracket; 8. knotted nylon rope; 9. water outlet; 10. sludge inlet; 11. bracket; 12. V-shaped steel plate; 13. biogas outlet. DETAILED DESCRIPTION

[0044] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and understand the present invention, and are not used to limit the present invention.

[0045] Embodiment A sewage treatment system

[0046] This embodiment is a sewage treatment system. Figure 1As shown, it includes a sewage inlet, which is connected to a screen channel, a water collection tank, a regulating tank, a primary anaerobic tank, an anaerobic lifting tank, a secondary anaerobic tank, an aerobic tank, a secondary sedimentation tank, a metering channel and a water outlet in sequence. The secondary sedimentation tank is connected to the primary anaerobic tank through a sludge tank to form a sludge circulation loop. The water collection tank is connected to the accident tank, and the accident tank is connected to the screen channel. The three form a circulation loop to deal with abnormal drainage of the workshop and alleviate system impact. The heights of the primary anaerobic tank and the anaerobic lifting tank are reduced in sequence; the heights of the secondary anaerobic tank, the aerobic tank and the secondary sedimentation tank are reduced in sequence. The stepped downward setting can make the water rely on gravity to automatically flow to the next unit, thereby reducing the energy consumption increased by using a water pump.

[0047] The first-level anaerobic tank hydrolyzes and acidifies the incoming water to initially decompose the macromolecular organic matter and improve its biodegradability. Figures 2 to 4 As shown, it is a sealed structure, with a water distribution device and an aeration device at the bottom, a double-layer bracket at the middle and lower part, a water outlet 9 and a sludge inlet 10 at the top of the side, and the water outlet 9 and the sludge inlet 10 are arranged opposite to each other.

[0048] The water distribution device includes three water inlets 1, a plurality of pipes 2 and 42 water outlets 3. The water outlets 3 are connected to the water inlets 1 through the pipes 2. One water inlet 1 is connected to a thick pipe, which is parallel to the horizontal plane. Seven thin pipes extend horizontally and evenly from both sides of the thick pipe. Each thin pipe then bends downward and perpendicular to the horizontal plane to connect to the water outlets 3. The water outlets 3 are evenly distributed at the bottom of the primary anaerobic tank.

[0049] The aeration device includes two gas inlets 4, a plurality of pipes 2 and eight gas outlets 5. The gas outlets 5 are connected to the gas inlets 4 through the pipes 2. One gas inlet 4 is connected to one pipe. The pipes are parallel to the horizontal plane. Four thin pipes are distributed on each pipe and are perpendicular to the horizontal plane and downward. The lower ends of the thin pipes are gas outlets 5. The gas outlets 5 are evenly distributed at the bottom of the primary anaerobic tank. The gas inlet 4 is connected to a blower, and air is delivered through the pipes 2 and the gas outlets 5.

[0050] The double-layer support includes an upper support 7 and a lower support 6. The upper support 7 is a steel rope with equal spacing and horizontal parallel distribution. The area formed by the upper support 7 is the same as the area of ​​the horizontal cross-section of the primary anaerobic tank, and the lower support 6 is symmetrically arranged therewith. Knotted nylon ropes 8 are connected at equal spacing between the double-layer supports. The nylon ropes 8 are perpendicular to the horizontal plane, and the distance between adjacent knots on the nylon rope 8 is 0. The knotted nylon rope can be an ordinary nylon rope. The adsorption of microorganisms is increased by knotting without adding other fillers.

[0051] The secondary anaerobic tank uses anaerobic microorganisms to degrade organic matter, such as Figure 5As shown, it is a sealed structure, with a water distribution device at the bottom, a three-phase separator in the middle, a biogas outlet 13 at the top, and a water outlet 9 at the top of the side.

[0052] The three-phase separator includes a bracket 11 and five V-shaped steel plates 12. The bracket 11 is a mesh surface obtained by welding angle steels. The bracket 11 is parallel to the horizontal plane and is used to support and place the V-shaped steel plates 12. The V-shaped steel plates 12 are obtained by welding the long sides of two rectangular steel plates. The V-shaped steel plates 12 are placed on the bracket 11 in an inverted V shape with equal intervals.

[0053] Aerobic pools use aerobic microorganisms to decompose pollutants and also perform nitrification, such as Figure 6 As shown, it is a sealed structure, an aeration device is arranged at the bottom, the gas outlet 5 in the aeration device is evenly distributed at the bottom of the aerobic tank, and a water outlet 9 and a water inlet 1 are arranged at the top of the side, and the water outlet 9 and the water inlet 1 are arranged opposite to each other.

[0054] The screen channel is used to intercept suspended matter in sewage to ensure the normal operation of the sewage treatment system; the collection tank is used to collect sewage treated by the screen channel and send it to the primary anaerobic tank; the anaerobic lifting tank is used to collect sewage from the primary anaerobic tank and send it to the secondary anaerobic tank; the secondary sedimentation tank is used for solid-liquid separation, the lower layer of sludge is circulated to the sludge tank, and the upper layer of clean water flows into the metering channel; the metering channel is used for water metering and water discharge.

[0055] It should be pointed out that the water distribution device in this embodiment includes at least one water inlet, at least one pipe and at least one water outlet. When the water distribution device can make the water outlets evenly distributed at the bottom of the primary anaerobic tank or the secondary anaerobic tank, it is within the scope of the description of this embodiment.

[0056] It should be pointed out that, in the present embodiment, the number of components in the water distribution device, the aeration device and the three-phase separator is fixed. When the sizes of the primary anaerobic tank, the secondary anaerobic tank and the aerobic tank change, or when the concentration of pollutants in the sewage increases, the number of components in the water distribution device, the aeration device and the three-phase separator can be appropriately increased or decreased, all within the scope of the present embodiment.

[0057] When using this embodiment, the pH of the sewage is 9-12, the COD in the sewage is 2200 mg / L, and the ammonia nitrogen is 35 mg / L. The sewage enters the sewage treatment system from the sewage inlet, and passes through the grid channel, the water collection tank, the regulating tank, the primary anaerobic tank, the anaerobic lifting tank, the secondary anaerobic tank, the aerobic tank, the secondary sedimentation tank, the metering channel and the outlet in sequence. The residence time of the sewage in the primary anaerobic tank, the secondary anaerobic tank and the aerobic tank is 1.5 h, 13.6 h and 3.4 h respectively. The sewage treated in the primary anaerobic tank has a pH of 6-7, a COD of 1350 mg / L, and ammonia nitrogen of 28 mg / L. The sewage treated in the secondary anaerobic tank has a pH of 6-7, a COD of 130 mg / L, and ammonia nitrogen of 6 mg / L. The sewage treated in the aerobic tank has a pH of 6-7, a COD of 25 mg / L, and ammonia nitrogen of 1 mg / L.

[0058] At the same time, the sludge in the secondary sedimentation tank is circulated to the sludge tank, and the sludge is circulated from the sludge tank to the primary anaerobic tank for sewage treatment again.

[0059] It should be noted that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A sewage treatment system, comprising a sewage inlet, characterized in that: The sewage inlet is connected in sequence to the pretreatment unit, the primary anaerobic tank, the secondary anaerobic tank, the aerobic tank, the post-treatment unit and the water outlet; The first-level anaerobic tank is a sealed structure with a water distribution device and an aeration device at the bottom, a double-layer bracket at the middle and lower part, knotted nylon ropes connecting the double-layer brackets, and a water outlet and a sludge inlet at the top of the side.

2. The sewage treatment system according to claim 1, characterized in that: The double-layer support comprises an upper support and a lower support. The upper support is a horizontally parallel distributed steel rope, and the lower support is symmetrically arranged therewith.

3. The sewage treatment system according to claim 2, characterized in that: The steel ropes in the upper bracket are distributed at equal intervals on the same horizontal plane; the area formed by the upper bracket is the same as the area of ​​the horizontal cross section of the primary anaerobic tank.

4. The sewage treatment system according to claim 1, characterized in that: The secondary anaerobic tank is a sealed structure, with a water distribution device at the bottom, a three-phase separator in the middle, a biogas outlet at the top, and a water outlet at the top of the side; An anaerobic lifting tank is arranged between the primary anaerobic tank and the secondary anaerobic tank.

5. The sewage treatment system according to claim 1 or 4, characterized in that: The water distribution device comprises at least one water inlet, at least one pipe and at least one water outlet, and the water outlet is connected to the water inlet through the pipe; The water outlets are evenly distributed at the bottom of the primary anaerobic tank or the secondary anaerobic tank.

6. The sewage treatment system according to claim 4, characterized in that: The three-phase separator includes a bracket and at least one V-shaped steel plate; The bracket is a mesh surface obtained by welding angle steels. The bracket is parallel to the horizontal plane, and the area formed by the bracket is the same as the area of ​​the horizontal cross section of the secondary anaerobic tank. The V-shaped steel plate is obtained by welding the long sides of two rectangular steel plates, and the V-shaped steel plates are placed on the bracket in an inverted V shape with equal intervals.

7. The sewage treatment system according to claim 1, characterized in that: The aerobic pool is a sealed structure with an aeration device at the bottom and a water outlet and a water inlet at the top of the side.

8. The sewage treatment system according to claim 1 or 7, characterized in that: The aeration device comprises at least one gas inlet, at least one pipeline and at least one gas outlet, wherein the gas outlet is connected to the gas inlet through the pipeline; the gas inlet is connected to the blower to supply air; The gas outlets are evenly distributed at the bottom of the primary anaerobic tank or aerobic tank.

9. The sewage treatment system according to claim 1, 4 or 7, characterized in that: The pre-treatment unit includes a screen channel, a water collection tank and an accident tank; The sewage inlet is connected to the screen channel, the screen channel is connected to the water collection tank, the water collection tank is connected to the primary anaerobic tank and the accident tank, the accident tank is connected to the screen channel, and the screen channel, the water collection tank and the accident tank form a circulation loop.

10. The sewage treatment system according to claim 1, 4 or 7, characterized in that: The post-treatment unit includes a secondary sedimentation tank and a metering channel. The secondary sedimentation tank is connected to the primary anaerobic tank through a sludge tank to form a sludge circulation loop.

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