A multi-stage purification treatment system for industrial wastewater

Abstract

The utility model relates to a kind of industrial wastewater multistage purification treatment system, and treatment system includes first adjusting pool, second adjusting pool, neutralization tank, primary sedimentation tank, coagulation reaction tank, secondary sedimentation tank, intermediate water pool, filter equipment, clean water pool, sludge thickening tank and plate-and-frame filter press.The utility model is cooperated by first grid well and second grid well, and the aperture of second grid well is greater than first grid well, first intercepts large particle impurities, then filters small impurities, effectively avoids pipeline blockage, and improves the operation stability of subsequent processing unit.

Description

Technical Field

[0001] This utility model relates to the technical field of industrial wastewater treatment, and in particular to a multi-stage purification system for industrial wastewater. Background Technology

[0002] Industrial wastewater has a complex composition, high and fluctuating pollutant concentrations, and direct discharge can cause serious damage to the aquatic ecosystem. Therefore, it must undergo strict purification treatment to meet standards before it can be discharged.

[0003] Existing industrial wastewater treatment systems have many shortcomings: The bar screen filtration process is mostly a single-stage setup with a fixed bar screen aperture, making it difficult to achieve graded filtration based on impurities of different particle sizes. This can easily lead to problems such as large particles clogging the pipes or small impurities leaking through the filter, affecting the efficiency of subsequent treatment. The filtrate after sludge treatment is directly discharged, causing secondary pollution. At the same time, some treatment units lack real-time monitoring methods and cannot adjust treatment parameters in a timely manner, which easily leads to unstable water quality. The equalization tank has a single function and is difficult to adapt to fluctuations in water quality and quantity from different sources of wastewater, resulting in uneven operating loads of subsequent treatment units and affecting the overall treatment effect.

[0004] In view of the above-mentioned shortcomings, the designer actively researched and innovated in order to create a multi-stage purification and treatment system for industrial wastewater, making it more valuable for industrial use. Utility Model Content

[0005] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a multi-stage purification and treatment system for industrial wastewater.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A multi-stage purification system for industrial wastewater includes a first equalization tank, a second equalization tank, a neutralization tank, a primary sedimentation tank, a coagulation reaction tank, a secondary sedimentation tank, an intermediate water tank, filtration equipment, a clear water tank, a sludge thickening tank, and a plate and frame filter press. The first water inlet pipe is connected to the first bar screen well located in the first regulating tank. The first regulating tank is connected to the second bar screen well located in the second regulating tank through the first liquid conveying pipe. The second water inlet pipe is connected to the second bar screen well located in the second regulating tank. The second equalization tank is connected in sequence to the neutralization tank, primary sedimentation tank, coagulation reaction tank, secondary sedimentation tank and intermediate water tank via the second liquid conveying pipeline. The intermediate water tank is connected to the filtration equipment via a third liquid delivery pipeline, and the filtration equipment is connected to the clear water tank via a fourth liquid delivery pipeline. The intermediate water tank is connected to the sludge thickening tank through several sedimentation and conveying pipes, and the sludge thickening tank is connected to the plate and frame filter press through sludge conveying pipes.

[0007] As a further improvement of this utility model, at least two dosing pipelines are installed on the coagulation reaction tank.

[0008] As a further improvement of this utility model, a discharge pipe is installed on the clear water tank.

[0009] As a further improvement of this utility model, a screw pump is installed on the sludge conveying pipeline.

[0010] As a further improvement of this utility model, a material conveying pipe and a return pipe are connected to the plate and frame filter press, and the return pipe is connected to the second grid well located in the second regulating tank.

[0011] As a further improvement of this utility model, pH meters and level gauges are installed on the neutralization tank, coagulation reaction tank, intermediate water tank and clear water tank.

[0012] As a further improvement of this utility model, both the primary sedimentation tank and the secondary sedimentation tank are inclined tube sedimentation tanks.

[0013] As a further improvement of this utility model, the grid aperture of the second grid well is larger than that of the first grid well.

[0014] As a further improvement of this utility model, the filtration device is a sand filter tank.

[0015] By means of the above solution, this utility model has at least the following advantages: This invention utilizes the cooperation of a first grid well and a second grid well, with the second grid well having a larger aperture than the first grid well. This first intercepts large particles of impurities and then filters out fine impurities, effectively preventing pipeline blockage and improving the operational stability of subsequent processing units.

[0016] The sludge of this invention is concentrated in a sludge thickening tank and then transported to a plate and frame filter press for dewatering via a screw pump. The slag produced by the filter press is transported off-site for disposal via a slag conveying pipeline, and the filtrate is returned to the second equalization tank for reprocessing via a return pipeline, thus avoiding secondary pollution.

[0017] The primary and secondary sedimentation tanks of this invention adopt inclined tube sedimentation tanks, which increases the sedimentation area and improves the sedimentation efficiency. The filtration equipment uses sand filter tanks, which can further remove fine suspended particles in wastewater and ensure excellent final effluent quality.

[0018] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the following are the preferred embodiments of this utility model and are described in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a multi-stage purification system for industrial wastewater according to this utility model.

[0021] The meanings of the labels in the figures are as follows.

[0022] 1. First inlet pipe; 2. First screen well; 3. First equalization tank; 4. First liquid conveying pipe; 5. Second inlet pipe; 6. Second screen well; 7. Second equalization tank; 8. Second liquid conveying pipe; 9. Neutralization tank; 10. Primary sedimentation tank; 11. Coagulation reaction tank; 12. Dosing pipeline; 13. Secondary sedimentation tank; 14. Intermediate water tank; 15. Third liquid conveying pipe; 16. Sedimentation conveying pipe; 17. Filtration equipment; 18. Fourth liquid conveying pipe; 19. Clear water tank; 20. Discharge pipe; 21. Sludge thickening tank; 22. Sludge conveying pipe; 23. Screw pump; 24. Plate and frame filter press; 25. Material and slag conveying pipe; 26. Return pipe. Detailed Implementation

[0023] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. 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 claimed invention, but merely to illustrate selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] The first embodiment of this utility model: like Figure 1As shown in the figure, this embodiment of an industrial wastewater multi-stage purification treatment system includes a first equalization tank 3, a second equalization tank 7, a neutralization tank 9, a primary sedimentation tank 10, a coagulation reaction tank 11, a secondary sedimentation tank 13, an intermediate water tank 14, a filtration device 17, a clear water tank 19, a sludge thickening tank 21, and a plate and frame filter press 24.

[0026] The connection relationships between the above processing pools are as follows: The first inlet pipe 1 is connected to the first bar screen well 2 located within the first regulating tank 3. The first regulating tank 3 is connected to the second bar screen well 6 located within the second regulating tank 7 via the first liquid conveying pipe 4. The second inlet pipe 5 is connected to the second bar screen well 6 located within the second regulating tank 7. The mesh size of the second bar screen well 6 is larger than that of the first bar screen well 2.

[0027] The second equalization tank 7 is connected in sequence to the neutralization tank 9, the primary sedimentation tank 10 (inclined tube sedimentation tank), the coagulation reaction tank 11, the secondary sedimentation tank 13 (inclined tube sedimentation tank), and the intermediate water tank 14 via the second liquid conveying pipe 8. At least two dosing pipes 12 are installed on the coagulation reaction tank 11, which can add different agents such as coagulants and coagulant aids respectively. The dosage can be precisely controlled according to the wastewater quality to promote the full flocculation of pollutants and improve the sedimentation treatment effect.

[0028] The intermediate water tank 14 is connected to the filtration equipment 17 (sand filter tank) via the third liquid conveying pipe 15. The filtration equipment 17 is connected to the clear water tank 19 via the fourth liquid conveying pipe 18. A discharge pipe 20 is installed on the clear water tank 19. The intermediate water tank 14 is connected to the sludge thickening tank 21 via several sedimentation conveying pipes 16. The sludge thickening tank 21 is connected to the plate and frame filter press 24 via the sludge conveying pipe 22. A screw pump 23 is installed on the sludge conveying pipe 22.

[0029] A material conveying pipe 25 and a return pipe 26 are connected to the plate and frame filter press 24. The return pipe 26 is connected to the second grid well 6 located in the second equalization tank 7.

[0030] pH meters and level gauges are installed in neutralization tank 9, coagulation reaction tank 11, intermediate water tank 14, and clear water tank 19. These allow for real-time monitoring of the pH value and water level in each unit, facilitating timely adjustments to treatment parameters and ensuring stable and compliant treated water quality.

[0031] The second embodiment of this utility model: like Figure 1 As shown, this embodiment of an industrial wastewater multi-stage purification system includes a first equalization tank, a second equalization tank, a neutralization tank, a primary sedimentation tank, a coagulation reaction tank, a secondary sedimentation tank, an intermediate water tank, filtration equipment, a clear water tank, a sludge thickening tank, and a plate and frame filter press. The first inlet pipe is connected to the first bar screen well located within the first equalization tank. The first equalization tank is connected to the second bar screen well located within the second equalization tank via a first liquid delivery pipe. The second inlet pipe is connected to the second bar screen well located within the second equalization tank. The bar screen aperture of the second bar screen well is larger than that of the first bar screen well, thus achieving staged filtration. The bar screen aperture of the first bar screen well is set to 2-5 mm to filter large particulate impurities such as stones and plastic blocks in industrial wastewater. The bar screen aperture of the second bar screen well is set to 5-10 mm to intercept larger impurities in the wastewater entering from the second inlet pipe and medium-sized impurities that have not been completely filtered in the effluent from the first equalization tank.

[0032] The second equalization tank is connected in sequence to the neutralization tank, primary sedimentation tank, coagulation reaction tank, secondary sedimentation tank and intermediate water tank via the second liquid delivery pipeline. The coagulation reaction tank is equipped with at least two dosing pipelines for precise dosing of different types of chemicals.

[0033] Both the first and second equalization tanks are equipped with stirring devices with a stirring rate of 30-50 rpm to balance the wastewater quality and quantity. The neutralization tank contains an automatic pH adjustment device linked to a pH meter, which can adjust the wastewater pH to a neutral range of 6-9. Both the primary and secondary sedimentation tanks are inclined tube sedimentation tanks made of polypropylene, with a tube length of 1000 mm and an inclination angle of 60 degrees. The coagulation reaction tank is equipped with a paddle agitator, with two stages of stirring: a fast stirring rate of 150-200 rpm for 1-2 minutes and a slow stirring rate of 30-50 rpm for 15-20 minutes. Two dosing lines are provided, one for adding polyaluminum chloride and the other for adding polyacrylamide.

[0034] The intermediate water tank is connected to the filtration equipment, which is a sand filter tank, via a third liquid delivery pipeline. The filtration equipment is connected to the clear water tank via a fourth liquid delivery pipeline, and a discharge pipeline is installed on the clear water tank.

[0035] The filter media of the filtration equipment is quartz sand, with two layers of particle size. The upper layer is fine sand of 1~2mm with a thickness of 500mm, and the lower layer is coarse sand of 2~4mm with a thickness of 300mm. The filtration speed is 8~10m / h.

[0036] The intermediate water tank is connected to the sludge thickening tank through several sedimentation and conveying pipes. The sludge thickening tank is connected to the plate and frame filter press through sludge conveying pipes. A screw pump is installed on the sludge conveying pipes. The plate and frame filter press is connected to the slag conveying pipe and the return pipe. The return pipe is connected to the second grid well located in the second equalization tank to realize the circulation treatment of the filter press filtrate.

[0037] pH meters and level gauges are installed on the neutralization tank, coagulation reaction tank, intermediate water tank and clear water tank. The primary sedimentation tank and secondary sedimentation tank are both inclined tube sedimentation tanks.

[0038] A brief description of the working process in this embodiment: 1. Staged Filtration and Water Quality Equalization: Industrial wastewater enters the system in two streams. One stream enters the first screen well in the first equalization tank through the first inlet pipe. After being filtered by a screen with a pore size of 2-5mm to remove large particles, it enters the first equalization tank and is balanced by a stirring device. The other stream enters the second screen well in the second equalization tank through the second inlet pipe. It merges with the effluent from the first equalization tank that is transported to the second screen well through the first liquid conveying pipe. After being filtered by a screen with a pore size of 5-10mm to remove larger impurities, the effluent enters the second equalization tank together, further stabilizing the water quality and quantity.

[0039] 2. Neutralization and Preliminary Sedimentation: Wastewater from the second equalization tank enters the neutralization tank through the second liquid delivery pipeline. A pH meter on the neutralization tank monitors the wastewater's pH value in real time. If the pH value is below 6, sodium hydroxide solution is automatically added; if the pH value is above 9, hydrochloric acid solution is automatically added, adjusting the wastewater's pH value to a neutral range of 6-9. The neutralized wastewater then enters the primary sedimentation tank. Utilizing the efficient sedimentation effect of the inclined tube sedimentation tank, suspended particles in the wastewater settle to the bottom of the tank under gravity, forming primary sludge. The supernatant then enters the coagulation reaction tank.

[0040] 3. Coagulation and Secondary Sedimentation: In the coagulation reactor, polyaluminum chloride (PAC) and polyacrylamide (PAM) are added to the wastewater via two dosing lines. First, rapid stirring ensures quick mixing of the chemicals with the wastewater, followed by slow stirring to promote the formation of larger flocs. The wastewater containing the flocs enters the secondary sedimentation tank, where, under the action of inclined tubes, the flocs settle to the bottom, forming secondary sludge. The supernatant then enters the intermediate water tank. The sludge produced in the primary and secondary sedimentation tanks is discharged through their respective sludge discharge pipes into the sedimentation and conveying pipeline, and then transported to the sludge thickening tank.

[0041] 4. Deep Filtration and Standardized Discharge: A pH meter and level gauge on the intermediate water tank monitor water quality and level in real time. Wastewater enters the sand filter tank of the filtration equipment through the third liquid delivery pipeline. The quartz sand filter media removes residual fine suspended particles from the wastewater through interception and adsorption. The deeply purified wastewater then enters the clear water tank through the fourth liquid delivery pipeline. A pH meter on the clear water tank monitors the effluent quality again. Once the pH value is confirmed to be within the range of 6-9 and other indicators meet standards, the wastewater is discharged into a natural water body or reused through the discharge pipeline.

[0042] 5. Sludge Treatment and Filtrate Recycling: A portion of the settled sludge in the intermediate tank, along with the primary and secondary settled sludge, enters the sludge thickening tank via a sedimentation conveying pipeline. In the thickening tank, it is concentrated for 12-24 hours to remove some water, forming thickened sludge. The thickened sludge is then conveyed through a sludge conveying pipeline to a plate and frame filter press under the action of a screw pump. It undergoes filter pressing and dewatering at a working pressure of 0.6-0.8 MPa, forming a sludge cake with a moisture content of less than 80%. This cake is then transported via a slag conveying pipeline to a designated location for landfill or incineration. The filtrate produced by the plate and frame filter press is returned to the second screen well in the second equalization tank via a return pipeline, re-entering the system for recycling and preventing direct discharge of the filtrate and secondary pollution.

[0043] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0045] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A multi-stage purification system for industrial wastewater, characterized in that: The treatment system includes a first equalization tank (3), a second equalization tank (7), a neutralization tank (9), a primary sedimentation tank (10), a coagulation reaction tank (11), a secondary sedimentation tank (13), an intermediate water tank (14), a filtration device (17), a clear water tank (19), a sludge thickening tank (21), and a plate and frame filter press (24). The first water inlet pipe (1) is connected to the first grid well (2) located in the first regulating tank (3). The first regulating tank (3) is connected to the second grid well (6) located in the second regulating tank (7) through the first liquid conveying pipe (4). The second water inlet pipe (5) is connected to the second grid well (6) located in the second regulating tank (7). The second regulating tank (7) is connected in sequence to the neutralization tank (9), the primary sedimentation tank (10), the coagulation reaction tank (11), the secondary sedimentation tank (13) and the intermediate water tank (14) via the second liquid conveying pipe (8); The intermediate water tank (14) is connected to the filtration device (17) through the third liquid delivery pipe (15), and the filtration device (17) is connected to the clear water tank (19) through the fourth liquid delivery pipe (18). The intermediate water tank (14) is connected to the sludge thickening tank (21) through several sedimentation and conveying pipes (16), and the sludge thickening tank (21) is connected to the plate and frame filter press (24) through the sludge conveying pipe (22).

2. The multi-stage industrial wastewater purification system as described in claim 1, characterized in that, At least two dosing lines (12) are installed on the coagulation reaction tank (11).

3. The multi-stage industrial wastewater purification system as described in claim 2, characterized in that, A discharge pipe (20) is installed on the clear water tank (19).

4. The multi-stage industrial wastewater purification system as described in claim 1, characterized in that, A screw pump (23) is installed on the sludge conveying pipeline (22).

5. The multi-stage industrial wastewater purification system as described in claim 1, characterized in that, A material conveying pipe (25) and a return pipe (26) are connected to the plate and frame filter press (24), and the return pipe (26) is connected to the second grid well (6) located in the second regulating tank (7).

6. The multi-stage industrial wastewater purification system as described in claim 1, characterized in that, pH meters and level gauges are installed on the neutralization tank (9), coagulation reaction tank (11), intermediate water tank (14) and clear water tank (19).

7. The multi-stage industrial wastewater purification system as described in claim 1, characterized in that, Both the primary sedimentation tank (10) and the secondary sedimentation tank (13) are inclined tube sedimentation tanks.

8. The multi-stage industrial wastewater purification system as described in claim 1, characterized in that, The aperture of the second grid well (6) is larger than that of the first grid well (2).

9. The multi-stage industrial wastewater purification system as described in claim 1, characterized in that, The filtration device (17) is a sand filter tank.

Images