Papermaking wastewater treatment method and filter sieve thereof

Abstract

The invention provides a papermaking wastewater treatment method and a filter sieve thereof. The filter sieve comprises a base, a sieve tank, a sieve mesh, a vibration unit and a buffer unit, the screen groove is connected with the base through the buffer unit, the top of the screen groove is of an open structure, the bottom of the screen groove is provided with the screen mesh, the vibration unit is fixedly connected with the screen groove and used for driving the screen groove to vibrate, a pulp inlet is formed in one end of the screen groove, and a slag outlet is formed in the other opposite end of the screen groove. A pulp discharging opening is formed in the position, located at the bottom of the screen groove, of the base, and the pulp discharging opening is used for discharging pulp filtered by the screen. According to the filter sieve for papermaking wastewater treatment provided by the embodiment of the invention, from the perspective of operation convenience, the screen mesh mounting and dismounting process is extremely convenient, and the equipment maintenance time and labor cost are greatly saved.

Description

Technical Field

[0001] The present application relates to the technical field of papermaking wastewater treatment, and in particular to a method for treating papermaking wastewater and a filter screen thereof. Background Art

[0002] In today's era of environmental protection and sustainable development, wastewater treatment in the papermaking industry has become a key issue. At present, domestic papermaking companies have certain limitations in the selection of wastewater pretreatment equipment. Most companies mainly use circular screens (centrifugal filter screens) as pretreatment equipment. The circular screen has obvious disadvantages when dealing with large particle impurities such as paper fluff in paint wastewater. Due to the limitations of its structure and working principle, the interception and separation effect of large particle impurities such as paper fluff is poor. A large amount of impurities such as paper fluff cannot be effectively removed, which directly increases the burden on the subsequent wastewater purification process and reduces the overall wastewater purification efficiency.

[0003] From an equipment maintenance perspective, circular screens are enclosed devices with only a small inspection hole, making cleaning the screen extremely difficult. Over time, large impurities easily accumulate on the screen surface. Failure to clean the screen promptly not only compromises its filtration performance but also accelerates its wear and tear. Once the screen is damaged, replacement is a cumbersome process, requiring significant time and financial investment, severely impacting the company's production schedule. More critically, if circular screen damage is not detected promptly, large particles such as paper fluff can slip through the damaged screen and enter the advanced treatment process. These large particles can severely damage membrane separation equipment, reducing its processing capacity and directly impacting the amount of paint wastewater it can treat. Furthermore, large impurities in the treated concentrate can reduce its quality, leading to quality issues in the finished paper, resulting in numerous customer complaints and damaging the company's market reputation. Furthermore, the discharge of substandard wastewater can pollute the surrounding environment, posing potential environmental risks and exposing the company to severe consequences such as environmental penalties. Summary of the Invention

[0004] A first aspect of an embodiment of the present application provides a filter screen for treating papermaking wastewater, the filter screen comprising: a base, a screen slot, a screen, a vibration unit and a buffer unit; the screen slot is connected to the base through the buffer unit, the top of the screen slot is an open structure, and the screen is arranged at the bottom; the vibration unit is fixedly connected to the screen slot for driving the screen slot to vibrate; a pulp inlet is provided at one end of the screen slot, and a slag discharge port is provided at the other opposite end; the base is provided with a pulp discharge port at the bottom of the screen slot, and the pulp discharge port is used to discharge the pulp filtered by the screen.

[0005] In some optional embodiments, the filter screen further includes a spray device, and the spray device is connected to the base via a bracket.

[0006] In some optional embodiments, the spraying device includes a connecting beam and a plurality of spray heads arranged on the connecting beam, and the spray heads are respectively connected to water pipes for spraying high-pressure water onto the screen.

[0007] In some optional embodiments, the spray device includes a drive motor and a transmission member, the transmission member is connected to the drive motor and the connecting beam respectively, and the drive motor is used to drive the connecting beam to move through the transmission member.

[0008] In some optional embodiments, the direction of movement of the connecting beam is from the pulp inlet of the screen slot toward the slag discharge outlet.

[0009] In some optional embodiments, the screen is multi-layered and the multi-layer screens are stacked and staggered.

[0010] In some optional embodiments, the buffer unit is a compression spring, and there are multiple of them, which are evenly arranged along the four sides of the sieve slot.

[0011] In some optional embodiments, the vibration unit includes a first vibration motor and a second vibration motor, wherein the vibration direction of the first vibration motor is the direction from the pulp inlet of the screen slot to the slag discharge port, the vibration direction of the second vibration motor is perpendicular to the vibration direction of the first vibration motor, the power of the first vibration motor is greater than the power of the second vibration motor, and thus the screen slot has an elliptical vibration trajectory

[0012] In a second aspect, an embodiment of the present application provides a method for treating papermaking wastewater, the method comprising:

[0013] Performing a first filtration on the wastewater using a first filter screen; wherein the first filter screen is the filter screen described in the above embodiment;

[0014] Using a second filter screen to filter the wastewater after the first filtration for a second time; wherein the size of the impurity particles in the first filtration is larger than the size of the impurity particles in the second filtration;

[0015] The wastewater that has been filtered for the second time is filtered for the third time using membrane separation equipment.

[0016] In some optional embodiments, the second filter screen is a centrifugal filter screen.

[0017] The filter screen for papermaking wastewater treatment provided in the embodiment of the present application is extremely convenient in terms of operational convenience, and the process of installing and disassembling the screen is extremely convenient, which greatly saves time and labor costs for equipment maintenance. During actual operation, the filter screen exhibits excellent anti-blocking performance, effectively avoiding production stagnation and efficiency reduction caused by blockage. When it is necessary to stop the machine to clean the outlet, the operation is simple and convenient, and ordinary staff can complete it quickly without complex tools and professional skills. These advantages not only ensure the efficient and stable operation of the wastewater treatment process, but also fundamentally achieve the goal of reducing pollutant emissions. Through the efficient purification of paint wastewater, the surrounding environmental quality is significantly improved, contributing to the construction of a green ecological environment. At the same time, it also strongly promotes the papermaking industry to stride forward in the direction of clean production, which meets the urgent needs of the industry's sustainable development. The present invention aims to fundamentally solve the above-mentioned problems of circular screens through innovative design and technology, achieve efficient treatment of paint wastewater, ensure paper quality, reduce environmental risks, and promote the sustainable development of the papermaking industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a filter screen for papermaking wastewater treatment according to the present application;

[0020] Figure 2 yes Figure 1 A schematic side view of the structure of the filter screen in the embodiment;

[0021] Figure 3 yes Figure 1 A schematic diagram of the top view of the filter screen in the embodiment;

[0022] Figure 4 This is a schematic diagram of the stacked structure of an embodiment of the screen of the present application;

[0023] Figure 5 This is a flow chart of an embodiment of a method for treating papermaking wastewater according to the present application;

[0024] Figure 6 It is a process flow node diagram in a specific embodiment of the papermaking wastewater treatment method of the present application. DETAILED DESCRIPTION

[0025] The present application will be further described in detail below in conjunction with the accompanying drawings and examples. It is particularly noted that the following examples are only intended to illustrate the present application and are not intended to limit the scope of the present application. Similarly, the following examples are only some examples of the present application and not all examples. All other examples obtained by those of ordinary skill in the art without creative work are intended to fall within the scope of protection of this application.

[0026] The terms "first", "second" and "third" in the embodiments of the present application are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second" and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, "multiple" means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined. All directional indications in the embodiments of the present application (such as up, down, left, right, front, back...) are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. The terms "including" and "having" in the embodiments of the present application and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or components inherent to these processes, methods, products or devices.

[0027] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In the papermaking industry, the effective treatment of coating wastewater has always been a key link in production quality and environmental protection. Currently, the widely used circular screens have exposed many serious problems when treating coating wastewater. The core purpose of this invention is to properly solve these difficult problems.

[0029] First of all, the circular screen (circular structure screen based on the centrifugal principle) shows extremely poor treatment effect when dealing with large particle impurities such as paper hair in paint wastewater. Large particle impurities such as paper hair are irregular in shape and flexible in texture. During the filtration process of the circular screen, they are easily entangled in the gaps of the screen and cannot be smoothly intercepted and discharged. As the treatment process continues, a large amount of large particle impurities such as paper hair continue to accumulate, but they cannot be effectively removed, which causes the circular screen's purification efficiency for wastewater to drop sharply. The equipment that should have been able to remove impurities efficiently has greatly increased the difficulty of the subsequent wastewater purification process due to its insufficient processing capacity for large particle impurities such as paper hair, and the working efficiency of the entire wastewater treatment system has been greatly reduced.

[0030] Secondly, the maintenance condition of the circular screen is worrying. Since the circular screen is a closed device with only narrow observation holes, it makes cleaning the screen very difficult. During the wastewater treatment process, various impurities will continue to adhere to the surface of the screen, but the limited space makes it difficult for cleaning tools to reach every corner of the screen for effective cleaning. Over time, the impurities on the surface of the screen will accumulate more and more, which will not only seriously affect the filtering performance of the screen, but also aggravate the wear of the screen, causing the screen to be easily damaged. Once the screen is damaged, the replacement process is extremely cumbersome. Professional technicians are required to disassemble the circular screen first, remove a series of complex components before accessing the screen, and then perform the replacement operation. After the replacement is completed, the equipment needs to be reassembled and debugged. This series of operations not only consumes a lot of time and labor costs, but also causes long-term production stagnation.

[0031] More critically, the enclosed structure of the circular screen makes it difficult to detect damaged screens in a timely manner. During actual production, workers struggle to fully and carefully inspect the screen's condition through the narrow inspection aperture. If screen damage is not detected promptly, large particles like paper fluff can pass unimpeded through the damaged screen and enter the advanced treatment process. Once these large impurities enter the membrane separation equipment, they can severely damage the delicate components within. Membrane separation technology relies on its high-precision filter membranes to achieve deep purification of wastewater. The ingress of large particles like paper fluff can scratch or clog the membranes, significantly reducing the equipment's processing capacity and directly impacting the amount of paint wastewater it can treat. Furthermore, damaged membrane separation equipment is unable to effectively remove impurities from the wastewater, resulting in a decline in the quality of the treated concentrate, which in turn affects the quality of the finished paper, leading to numerous customer complaints and severely damaging the company's market reputation. Furthermore, the discharge of substandard wastewater pollutes the surrounding environment, posing potential environmental risks and exposing the company to severe consequences such as environmental penalties.

[0032] In today's era of environmental protection and sustainable development, wastewater treatment in the papermaking industry has become a key issue. This invention deeply addresses the crucial technical field of papermaking coating wastewater treatment, precisely targeting and meticulously developing a highly efficient purification process specifically for coating wastewater generated during the white cardboard production process. During the white cardboard production process, coating wastewater has a complex composition and contains large particles such as paper fibers, which poses a significant challenge to wastewater treatment. The treatment process provided by this invention offers unique advantages for treating this type of wastewater.

[0033] In view of this, the embodiment of the present application first provides a structure of an open planar rectangular structure screen, please refer to Figures 1 to 3 , Figure 1 This is a schematic diagram of the overall structure of an embodiment of a filter screen for papermaking wastewater treatment in this application. Figure 2 yes Figure 1 A schematic side view of the filter screen in the embodiment, Figure 3 yes Figure 1 Schematic diagram of the top structure of the filter screen in the embodiment; the filter screen in this embodiment includes but is not limited to the following structures: a base 110, a screen slot 120, a screen 130, a vibration unit 140 and a buffer unit 150.

[0034] Specifically, the sieve slot 120 is connected to the base 110 through the buffer unit 150. The top of the sieve slot 120 is an open structure and the whole can be rectangular. A sieve 130 is set at the bottom of the sieve slot 120. The vibration unit 140 is fixedly connected to the sieve slot 120 and is used to drive the sieve slot 120 to vibrate. A slurry inlet 121 is provided at one end of the sieve slot 120, and a slag discharge port 122 is provided at the other opposite end. The base 110 is located at the bottom of the sieve slot 120 and is provided with a slurry discharge port 111. The slurry discharge port 111 is used to discharge the slurry filtered by the sieve 130.

[0035] The papermaking wastewater (slurry) to be filtered enters the filter screen through the slurry inlet 121. After the slurry is filtered through the screen 130, the large particles of slag are discharged through the slag discharge port 122. The filtered liquid is discharged through the slurry discharge port 111 at the bottom of the screen slot 120 of the base 110 and enters the subsequent filtration process.

[0036] Optionally, the buffer unit 150 in this embodiment is a compression spring, and there are multiple of them, which are evenly arranged along the four sides of the sieve slot 120 .

[0037] Optionally, the vibration unit 140 in this embodiment includes a first vibration motor 141 and a second vibration motor 142, wherein the vibration direction of the first vibration motor 141 is the direction from the pulp inlet 121 of the screen slot 120 to the slag discharge port 122 (X direction in the figure), and the vibration direction of the second vibration motor 142 is perpendicular to the vibration direction of the first vibration motor 141 (Y direction in the figure). The power of the first vibration motor 141 is greater than the power of the second vibration motor 142, and the screen slot 120 has an elliptical vibration trajectory. In addition, the first vibration motor 141 and the second vibration motor 142 are both set at an angle to the horizontal plane, for example, an angle of 45 degrees.

[0038] The configuration of the vibration unit 140 in this embodiment facilitates the flow of slurry toward the slag discharge port 122 (vertically, in the X direction), while also enabling lateral vibration (in the Y direction), thereby improving vibration efficiency. The first vibration motor 141 may be two 1.2 kW vibration motors, and the second vibration motor 142 may be a single 0.4 kW vibration motor.

[0039] See also Figure 4 , Figure 4 This is a schematic diagram of the stacked structure of one embodiment of the screen of the present application. The screen 130 in this embodiment is multi-layered, staggered, and the arrow X in the figure indicates the direction of slurry flow and slag discharge. The multi-layered screen 130 facilitates removal and replacement, and the staggered stacking reduces slurry leakage.

[0040] Optionally, see Figures 1 to 3 The filter screen in this embodiment further includes a spray device 160, which is connected to the base 110 via a bracket 170. The spray device 160 is used to spray high-pressure water onto the screen 130. The spray device 160 includes a connecting beam 161 and a plurality of spray heads 162 disposed on the connecting beam 161. The spray heads 162 are respectively connected to water pipes (not shown) to spray high-pressure water onto the screen 130.

[0041] Optionally, the spray device 160 in this embodiment includes a drive motor 163 and a transmission member (not shown). The transmission member is connected to the drive motor 163 and the connecting beam 161, respectively. The drive motor 163 is used to drive the connecting beam 161 to move via the transmission member. The direction of movement of the connecting beam 161 is from the slurry inlet 121 of the screen slot 120 to the slag discharge port 122, that is, the X direction in the figure. The transmission member may include a gear rack or other structure, which is within the scope of understanding of those skilled in the art and will not be further described here.

[0042] In the complex challenges of coating wastewater treatment, traditional treatment methods are unable to effectively deal with the many problems caused by large particulate matter such as paper fibers. To overcome this dilemma, we innovatively introduced rectangular screen pretreatment equipment, combined with circular screen pretreatment equipment and membrane separation technology treatment equipment to construct a set of advanced multi-stage collaborative purification methods for coating wastewater treatment (the specific treatment method will be described in detail in subsequent embodiments). In the past, pretreatment relied solely on a single circular screen, and when faced with coating wastewater with complex components, the treatment effect was difficult to meet standards. This solution organically combines the two screen devices to achieve graded filtration of wastewater.

[0043] Rectangular screen (the filter screen structure in this example): Among the various pretreatment equipment, the rectangular screen is the key to this innovation. It boasts a unique design with a maximum processing capacity of 500 GPM (gallons per minute, 113.5 m³ / hour). Equipment dimensions: See the data in the figure below. Screen: Four 23-inch x 43-inch (584 mm x 1092 mm) pre-tensioned screens with a 200-mesh opening. Screening area: A total of 29.4 square feet (approximately 1.9 m²). Screen angle: Adjustable from +3° to -3°. Standard vibrators: Two 1.9 HP (approximately 1.42 kW) vibrators; one 0.7 HP (approximately 0.52 kW) vibrator.

[0044] The rectangular screen, with its unique structure and reasonable mesh size, can be the first to intercept large particles of impurities. For large particles such as paper fibers with a length of 5 to 20 mm and a diameter of 1 to 5 mm, the interception efficiency can reach over 90%, effectively reducing the processing pressure of the subsequent circular screen. The circular screen uses slightly smaller meshes to perform a secondary fine filtration on the wastewater after the initial treatment of the rectangular screen, further removing particles with a particle size of 0.15 to 5 mm. The two work together to increase the overall efficiency of wastewater pretreatment by 30% to 50%. This combination of large-sized screen surface and reasonable mesh size greatly increases the contact area between the wastewater and the screen surface, and can quickly and efficiently intercept large particles such as paper fibers at a rate of 20 to 40 cubic meters of wastewater per hour (concentration of 2% to 15%). Moreover, the mesh of the rectangular screen is made of 316L stainless steel, which has high strength and corrosion resistance. It can operate continuously and stably for 720 hours without frequent replacement, greatly reducing maintenance costs.

[0045] In addition, the filter screen in this embodiment is equipped with an automatic water spraying system, which has the following features. Anti-caking design: The automatic water spraying system added to the rectangular screen is a major innovative highlight. Large particles in the paint wastewater are very likely to form lumps after contact with air, which brings many problems to wastewater treatment. The automatic water spraying system uses 12 high-pressure nozzles arranged in a line with an installation height of 9 cm. The working pressure is set at 2-5 MPa. It automatically starts every 5-10 minutes, and each spraying lasts for 30-60 seconds. The high-pressure water flow covers the screen in a fan-shaped or cone-shaped spray pattern, ensuring that large particles of impurities are always wet, effectively avoiding the occurrence of caking. This not only ensures the smooth flow of the wastewater outlet and maintains a stable flow rate for wastewater treatment, but also extends the service life of the screen, extending the screen replacement cycle by 2-3 times, and significantly reducing equipment maintenance costs. The spraying water comes from ultrafiltration permeate water (the permeate water is clear and can be discharged directly), without the need for additional clean water and energy consumption and without incurring additional production costs.

[0046] The filter screen in this embodiment adopts an open screen plate design, which has the characteristics of convenient maintenance: the rectangular screen adopts an open screen slot, which is completely different from the closed structure of the traditional circular screen. The open screen slot allows staff to directly access various parts of the screen, which is convenient for regular manual cleaning. When cleaning, use an ordinary water gun or brush to complete a comprehensive cleaning within 30 to 60 minutes. Moreover, when the screen needs to be replaced, due to the open design, there is no need for a complicated disassembly process. With the help of simple tools, a single person can complete the disassembly and replacement of the screen plate within 1 to 2 hours, which greatly saves maintenance time and labor costs.

[0047] The filter screen for papermaking wastewater treatment provided in the embodiment of the present application is extremely convenient in terms of operational convenience, and the process of installing and disassembling the screen is extremely convenient, which greatly saves time and labor costs for equipment maintenance. During actual operation, the filter screen exhibits excellent anti-blocking performance, effectively avoiding production stagnation and efficiency reduction caused by blockage. When it is necessary to stop the machine to clean the outlet, the operation is simple and convenient, and ordinary staff can complete it quickly without complex tools and professional skills. These advantages not only ensure the efficient and stable operation of the wastewater treatment process, but also fundamentally achieve the goal of reducing pollutant emissions. Through the efficient purification of paint wastewater, the surrounding environmental quality is significantly improved, contributing to the construction of a green ecological environment. At the same time, it also strongly promotes the papermaking industry to stride forward in the direction of clean production, which meets the urgent needs of the industry's sustainable development. The present invention aims to fundamentally solve the above-mentioned problems of circular screens through innovative design and technology, achieve efficient treatment of paint wastewater, ensure paper quality, reduce environmental risks, and promote the sustainable development of the papermaking industry.

[0048] In addition, the present invention also provides a method for treating papermaking wastewater. Figure 5 , Figure 5 1 is a flow chart of an embodiment of a method for treating papermaking wastewater of the present application, wherein the treatment method includes but is not limited to the following steps.

[0049] Step S100: Filter the wastewater for the first time using a first filter screen.

[0050] The first filter screen is the filter screen in the aforementioned embodiment.

[0051] In step S200 , the wastewater that has been filtered for the first time is filtered for the second time using a second filter screen; wherein the size of the impurity particles in the first filtration is larger than the size of the impurity particles in the second filtration.

[0052] In step S200, the second filter is a circular centrifugal filter, also known as a round screen. The round screen pretreatment equipment operates at a steady speed of 1000-1500 RPM, using centrifugal force to fling large particles in the wastewater toward the screen, achieving separation from the wastewater. Working in conjunction with the rectangular screen, it further removes remaining large particles in the wastewater, improving the pretreatment effect.

[0053] Step S300: Using a membrane separation device to filter the wastewater after the second filtration for a third time.

[0054] In this step, the membrane separation equipment uses an ultra-fine filtration membrane with a pore size of 0.01 to 0.1 microns, which can accurately separate substances of different particle sizes in the wastewater, effectively improving the accuracy and quality of paint wastewater treatment, deep purification and resource recovery.

[0055] See also Figure 6 , Figure 6 It is a process flow node diagram in a specific embodiment of the papermaking wastewater treatment method of the present application, which includes paint workstation wastewater 601, first filter screen filtration 602, wastewater tank 603, second filter screen filtration 604, feeding tank 605, wastewater feeding filter 606, membrane separation equipment 607, water ring secondary treatment 608, concentrate tank 609 and primer coating 610.

[0056] Through this comprehensive multi-stage coordinated purification process, an efficient, economical, and environmentally friendly paint wastewater purification solution has been developed. The membrane separation technology treatment equipment utilizes ultrafiltration or reverse osmosis membranes with pore sizes ranging from 0.01 to 0.1 microns. This technology has an extremely high removal rate for tiny particles, colloids, and organic matter in the wastewater, ensuring that the wastewater meets discharge standards. Chemical oxygen demand (COD) removal rates can reach 80% to 90%, and suspended solids (SS) removal rates exceed 95%. Furthermore, the treatment process recovers 70% to 80% of useful resources in the wastewater, such as fillers like kaolin and calcium carbonate, avoiding unnecessary raw material waste and reducing production costs. The efficient operation of the entire treatment process increases production efficiency by 20% to 30%, giving the company a cost advantage in market competition and achieving a win-win situation in both economic and environmental benefits.

[0057] Before this invention was adopted, large particles like paper fluff severely impacted wastewater treatment efficiency, reducing the flow rate of treatment equipment by 20%, increasing equipment failure rates by 15%, and severely shortening the lifespan of ultrafiltration membranes. Furthermore, it reduced the amount of coating wastewater treated by approximately 30%, impacting the quality of the treated concentrate, leading to customer complaints about paper quality and environmental risks.

[0058] After the multi-stage coordinated purification treatment in the embodiment of the present application, the solid content of the ultrafiltration concentrate is stably maintained in the range of 28% to 32%, and the ultrafiltration concentrate residue is controlled at a level of ≦1500ppm. All indicators meet the production requirements, effectively ensuring the smooth progress of subsequent production processes, improving product quality, and reducing environmental risks.

[0059] The above descriptions are only some embodiments of the present application and do not limit the scope of protection of the present application. Any equivalent device or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of this application.

Claims

1. A filter screen for papermaking wastewater treatment, characterized in that: The filter screen includes: a base, a screen slot, a screen, a vibration unit and a buffer unit; the screen slot is connected to the base through the buffer unit, the top of the screen slot is an open structure, and the screen is arranged at the bottom, the vibration unit is fixedly connected to the screen slot, and is used to drive the screen slot to vibrate, one end of the screen slot is provided with a slurry inlet, and the other end is provided with a slag discharge port, the base is located at the bottom of the screen slot and is provided with a slurry discharge port, and the slurry discharge port is used to discharge the slurry filtered by the screen.

2. The filter screen according to claim 1, characterized in that The filter screen further comprises a spray device, which is connected to the base via a bracket.

3. The filter screen according to claim 2, characterized in that The spraying device includes a connecting beam and a plurality of spray heads arranged on the connecting beam. The spray heads are respectively connected to water pipes and are used to spray high-pressure water onto the screen.

4. The filter screen according to claim 3, characterized in that The spray device includes a driving motor and a transmission member, wherein the transmission member is connected to the driving motor and the connecting beam respectively, and the driving motor is used to drive the connecting beam to move through the transmission member.

5. The filter screen according to claim 4, characterized in that The direction in which the connecting beam moves is the direction from the pulp inlet of the screen slot toward the slag discharge outlet.

6. The filter screen according to claim 1, characterized in that The screen is multi-layered and the multi-layer screens are stacked and staggered.

7. The filter screen according to claim 1, characterized in that The buffer unit is a compression spring, and there are multiple of them, which are evenly arranged along the four sides of the sieve slot.

8. The filter screen according to claim 1, characterized in that The vibration unit includes a first vibration motor and a second vibration motor, wherein the vibration direction of the first vibration motor is the direction from the pulp inlet of the screen slot to the slag discharge port, the vibration direction of the second vibration motor is perpendicular to the vibration direction of the first vibration motor, the power of the first vibration motor is greater than the power of the second vibration motor, and thus the screen slot has an elliptical vibration trajectory.

9. A method for treating papermaking wastewater, characterized in that: The processing method comprises: Performing a first filtration on the wastewater using a first filter screen; wherein the first filter screen is the filter screen according to any one of claims 1 to 8; Using a second filter screen to filter the wastewater after the first filtration for a second time; wherein the size of the impurity particles in the first filtration is larger than the size of the impurity particles in the second filtration; The wastewater that has been filtered for the second time is filtered for the third time using membrane separation equipment.

10. The processing method according to claim 9, characterized in that: The second filter screen is a centrifugal filter screen.

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