A multi-stage treatment and reuse system for paper mill white water

Abstract

The application belongs to the technical field of white water treatment, and particularly relates to a paper mill white water multi-stage treatment and recycling system, which comprises a white water collecting module, the white water collecting module is connected with a water quality online monitoring module, the water quality online monitoring module is connected with a pretreatment adjusting module, the pretreatment adjusting module is connected with a flocculant automatic adding module, the flocculant automatic adding module is connected with a high-efficiency flocculation reaction module, the high-efficiency flocculation reaction module is connected with a multi-disc filtering module, and the multi-disc filtering module is connected with a filtrate shunt module, the application realizes efficient and refined multi-stage treatment and recycling, significantly improves the overall efficiency of the system and the value of the recycled materials, builds an intelligent closed-loop control system with data driving as the core, guarantees efficient, stable and low-cost operation of the system, forms a sustainable closed-loop operation mode integrating energy saving, bacteriostasis and safety protection, and improves the reliability and environmental friendliness of the system.

Description

Technical Field

[0001] This invention relates to the field of white water treatment technology, and in particular to a multi-stage white water treatment and reuse system for paper mills. Background Technology

[0002] The papermaking process generates a large amount of white water, which contains high concentrations of fine fibers, fillers (such as calcium carbonate and kaolin), and dissolved colloidal substances (DCS). Direct discharge not only wastes valuable fiber resources and chemicals but also leads to serious water pollution. Currently, the industry commonly uses single or simple combinations of physicochemical methods to treat white water, such as flotation, sedimentation, or multi-disc filtration. However, these methods have the following limitations: Limited processing efficiency: Traditional methods are not effective at removing fine fillers and colloidal substances, which lead to their continuous accumulation in the system, affecting paper machine operation and paper quality.

[0003] Insufficient resource recycling: Recycled fibers and fillers are often unmodified or unoptimized. Direct reuse may have a negative impact on product quality and make it difficult to achieve high added value utilization.

[0004] The system has a low level of intelligence: key process parameters such as dosing and filtration rely heavily on manual experience for adjustment, making it difficult to cope with fluctuations in water quality and quantity, resulting in unstable operation and high costs.

[0005] The system is not closed-loop: the reuse path of treated water and recycled materials is singular, and the maximum reuse of water, fiber and filler in the whole system by grade and quality cannot be maximized. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by proposing a multi-stage white water treatment and reuse system for paper mills.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A multi-stage white water treatment and reuse system for a paper mill includes a white water collection module connected to an online water quality monitoring module, which in turn is connected to a pretreatment and conditioning module. The pretreatment and conditioning module is connected to an automatic flocculant dosing module, which is connected to a high-efficiency flocculation reaction module. The high-efficiency flocculation reaction module is connected to a multi-disc filtration module, which is connected to a filtrate diversion module. The filtrate diversion module is connected to a fiber recovery liquor concentration module, which is connected to a filler modification and addition module. The filler modification and addition module is connected to an inclined screen filtration and recovery module, which is connected to an energy dissipation and water distribution module. It can be connected to a screw conveyor dewatering module, which in turn is connected to a reuse slurry preparation module. The reuse slurry preparation module is connected to an intelligent control system module, which is connected to a cleaning and maintenance module. The cleaning and maintenance module is connected to a sludge treatment module, which is connected to a clean water reuse module. The clean water reuse module is connected to an effluent detection module, which is connected to a data storage and analysis module. The data storage and analysis module is connected to an energy recovery module, which is connected to a chemical recycling module. The chemical recycling module is connected to a microbial inhibition module, which is connected to a system safety protection module.

[0008] Preferably, the white water collection module is used to collect white water from various sections of the paper machine, the online water quality monitoring module is used to detect the chemical oxygen demand, total solids, dissolved and colloidal substances, dissolved matter, pH value and flow parameters of the white water in real time, and the pretreatment adjustment module is used to adjust the flow rate and concentration of the white water, buffer water quality fluctuations, and provide stable conditions for subsequent treatment.

[0009] Preferably, the automatic flocculant dosing module is used to dynamically calculate and add a flocculant solution composed of PAC and PAM based on water quality data; the high-efficiency flocculation reaction module is equipped with two or more mechanical stirring zones to ensure that suspended particles and colloidal substances in white water fully contact and react with the flocculant to form easily separable flocs.

[0010] Preferably, the multi-disc filtration module is used to intercept and recover flocculated fibers and filler flocs. The multi-disc filtration module includes fan blades with stainless steel filter screens. Each fan blade is divided into two stripping zones and equipped with an air valve to accelerate filtrate discharge and improve stripping efficiency. The filtrate diversion module divides the filtrate into ultra-clear filtrate and clear filtrate according to the solid content, and directs them to different reuse points. The fiber recovery liquid concentration module further concentrates the recovered concentrated fiber pulp.

[0011] Preferably, the filler modification and addition module adds specific polymeric modifying chemicals to the concentrated slurry, causing the fine fillers and colloidal substances in the slurry to adhere more firmly to the fiber surface; the inclined screen filtration and recovery module is used to treat the effluent or other low-concentration wastewater after multi-disc filtration, and further recover the residual fibers therein.

[0012] Preferably, the energy dissipation and water distribution module includes a water distribution tank, an energy dissipation wall, and a water distribution trough, which are used to distribute the incoming water evenly and stably on the inclined wire mesh; the screw conveyor dewatering module is used to collect the fibers that slip off the inclined wire mesh and perform preliminary dewatering; the recycled pulp preparation module mixes and prepares the modified pulp with the fibers recovered from the inclined wire mesh according to the process requirements and sends it back to the papermaking workshop for reuse.

[0013] Preferably, the intelligent control system module is based on programmable logic controller and Internet of Things technology to realize centralized monitoring, automatic adjustment and optimization of the entire system's operating parameters; the cleaning and maintenance module automatically performs high-pressure water flushing of the multi-disc filter and inclined screen, as well as backflushing of the system pipelines; and the sludge treatment module performs concentration, pressure filtration and drying treatment of the generated chemical sludge.

[0014] Preferably, the clean water reuse module stores and pumps the ultra-clean filtrate and clean filtrate that meet the process requirements to different water usage points in the papermaking workshop for reuse; the effluent detection module monitors the chemical oxygen demand and suspended solids key indicators of the effluent online.

[0015] Preferably, the data storage and analysis module stores all operation and detection data, and performs energy efficiency analysis, fault prediction and process optimization suggestions through built-in algorithms; the energy recovery module recovers energy by utilizing the residual pressure or heat of the fluid during the treatment process; the reagent recycling module collects and treats wastewater containing incompletely reacted flocculants, recovers the effective components and reuses them in the flocculant automatic dosing module.

[0016] Preferably, the microbial inhibition module is installed in the white water collection tank or the clean water reuse tank, and uses an ultraviolet irradiator or a low-dose ozone generator to inhibit the growth of microorganisms and putrefaction in the system; the system safety protection module includes a pressure sensor, a leak detection sensor, an overload protector and an emergency stop button to ensure the safe operation of the system.

[0017] Compared with the prior art, the advantages of the present invention are as follows: 1. It achieves efficient and refined multi-level processing and resource recycling, significantly improving the overall efficiency of the system and the value of recyclables.

[0018] Through the collaboration of the high-efficiency flocculation reaction module and the multi-disc filtration module, most of the suspended solids are efficiently removed first. Subsequently, the filtrate diversion module separates the filtrate according to its quality. The clean water reuse module directly reuses the high-quality water, reflecting the hierarchical utilization of water. At the same time, the fiber recovery liquid concentration module, the filler modification and addition module, and the recycled pulp preparation module form the main material processing line. Not only are fibers and fillers recovered, but the retention performance of the recovered fillers and the paper quality are improved through chemical modification. The inclined screen filtration and recovery module, as the final checkpoint, cooperates with the main line to achieve the ultimate recovery of fibers, jointly constituting a maximum resource recovery system for the "water-fiber-filler" all elements with hierarchical separation of quality.

[0019] 2. An intelligent closed-loop control system with data-driven as the core is constructed, ensuring the efficient, stable and low-cost operation of the system.

[0020] As the core, the intelligent control system module receives the feedback data from the online water quality monitoring module and the discharged water detection module in real time, dynamically commands the automatic flocculant dosing module to achieve precise dosing, and optimizes the process and predicts faults through the data storage and analysis module. This intelligent closed-loop also extends to the automatic start and stop of the cleaning and maintenance module, as well as the recycling and reuse of residual chemicals by the chemical agent recycling module. This multi-module linkage enables the system to adapt to fluctuations in water quality and quantity, significantly reducing chemical consumption and manual intervention, and achieving stable compliance and optimized operating costs.

[0021] 3. A sustainable closed-loop operation mode integrating energy conservation, antibacterial and safety protection is formed, improving the reliability and environmental friendliness of the system.

[0022] The system not only completes the main treatment process, but also recovers the residual pressure / heat through the energy recovery module, controls the growth of organisms through the microorganism inhibition module (such as ultraviolet rays) to ensure the hygiene of the recycled water. The sludge treatment module properly disposes of the final solid waste, while the system safety protection module provides hardware protection for the whole process. These auxiliary modules cooperate closely with the core treatment module to jointly build a complete water circulation closed-loop of energy conservation, consumption reduction, clean production, safety and reliability, significantly improving the sustainability of the entire white water treatment system. Brief Description of the Drawings

[0023] Figure 1 It is a system diagram of a white water multi-stage treatment and reuse system proposed by the present invention for a paper mill; Figure 2 It is a block diagram of the energy dissipation and water distribution module of a white water multi-stage treatment and reuse system proposed by the present invention for a paper mill; Figure 3 It is a block diagram of the online water quality monitoring module of a white water multi-stage treatment and reuse system proposed by the present invention for a paper mill; Figure 4This is a block diagram of the data storage and analysis module of a multi-stage white water treatment and reuse system for paper mills proposed in this invention. Figure 5 This is a block diagram of the system safety protection module of a multi-stage white water treatment and reuse system for paper mills proposed in this invention. Detailed Implementation

[0024] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this embodiment, and not all embodiments.

[0025] Example 1 Reference Figures 1-5 A multi-stage white water treatment and reuse system for paper mills includes a white water collection module, a water quality online monitoring module, a pretreatment and conditioning module, an automatic flocculant dosing module, a high-efficiency flocculation reaction module, a multi-disc filtration module, a filtrate diversion module, a fiber recovery liquor concentration module, a filler modification and addition module, an inclined screen filtration and recovery module, and an energy dissipation and water distribution module. The system is connected to a screw conveyor dewatering module, which in turn is connected to a reuse slurry preparation module. The reuse slurry preparation module is connected to an intelligent control system module, which is connected to a cleaning and maintenance module. The cleaning and maintenance module is connected to a sludge treatment module, which is connected to a clean water reuse module. The clean water reuse module is connected to an effluent detection module, which is connected to a data storage and analysis module. The data storage and analysis module is connected to an energy recovery module, which is connected to a chemical recycling module. The chemical recycling module is connected to a microbial inhibition module, which is connected to a system safety protection module.

[0026] In this embodiment, the white water collection module is used to collect white water from various sections of the paper machine, the online water quality monitoring module is used to detect the chemical oxygen demand, total solids, dissolved and colloidal substances, dissolved matter, pH value and flow parameters of the white water in real time, and the pretreatment adjustment module is used to adjust the flow rate and concentration of the white water, buffer water quality fluctuations, and provide stable conditions for subsequent treatment.

[0027] In this embodiment, the automatic flocculant dosing module is used to dynamically calculate and add a flocculant solution composed of PAC and PAM based on water quality data; the high-efficiency flocculation reaction module is equipped with two or more mechanical stirring zones, so that the suspended particles and colloidal substances in the white water can fully contact and react with the flocculant to form easily separable flocs.

[0028] In this embodiment, the multi-disc filtration module is used to intercept and recover flocculated fibers and filler flocs. The multi-disc filtration module includes fan blades with stainless steel filter screens. Each fan blade is divided into two stripping zones and equipped with an air valve to accelerate filtrate discharge and improve stripping efficiency. The filtrate diversion module divides the filtrate into ultra-clear filtrate and clear filtrate according to the solid content, and directs them to different reuse points. The fiber recovery liquid concentration module further concentrates the recovered concentrated fiber pulp.

[0029] In this embodiment, the filler modification and addition module adds specific polymeric modifying chemicals to the concentrated slurry, which promotes the more firm adhesion of the fine fillers and colloidal substances in the slurry to the fiber surface; the inclined screen filtration and recovery module is used to treat the effluent or other low-concentration wastewater after multi-disc filtration, and further recover the residual fibers therein.

[0030] In this embodiment, the energy dissipation and water distribution module includes a water distribution tank, an energy dissipation wall, and a water distribution trough, which are used to distribute the incoming water evenly and stably on the inclined wire mesh; the screw conveyor dewatering module is used to collect the fibers that slip off the inclined wire mesh and perform preliminary dewatering; the recycled pulp preparation module mixes and prepares the modified pulp with the fibers recovered from the inclined wire mesh according to the process requirements and sends it back to the papermaking workshop for reuse.

[0031] In this embodiment, the intelligent control system module is based on programmable logic controller and Internet of Things technology to realize centralized monitoring, automatic adjustment and optimization of the operating parameters of the entire system; the cleaning and maintenance module automatically performs high-pressure water flushing of multi-disc filters and inclined screens, as well as backflushing of system pipelines; and the sludge treatment module performs concentration, filtration and drying of the generated chemical sludge.

[0032] In this embodiment, the clean water reuse module stores and pumps the ultra-clean filtrate and clean filtrate that meet the process requirements to different water usage points in the papermaking workshop for reuse; the effluent detection module monitors the chemical oxygen demand and suspended solids key indicators of the effluent online.

[0033] In this embodiment, the data storage and analysis module stores all operation and detection data, and performs energy efficiency analysis, fault prediction and process optimization suggestions through built-in algorithms; the energy recovery module recovers energy by utilizing the residual pressure or heat of the fluid during the treatment process; the reagent recycling module collects and treats wastewater containing incompletely reacted flocculants, recovers the effective components and reuses them in the automatic flocculant dosing module.

[0034] In this embodiment, the microbial inhibition module is installed in the white water collection tank or the clean water reuse tank, and uses an ultraviolet irradiator or a low-dose ozone generator to inhibit the growth of microorganisms and putrefaction in the system; the system safety protection module includes a pressure sensor, a leak detection sensor, an overload protector and an emergency stop button to ensure the safe operation of the system.

[0035] Working principle: The white water produced in the paper mill first enters the collection tank of the white water collection module. Sensors from the online water quality monitoring module installed in the tank transmit water quality data to the intelligent control system module in real time.

[0036] White water is pumped to the homogenization tank of the pretreatment and conditioning module. After the water volume and quality are adjusted, it enters the high-efficiency flocculation reaction module. Simultaneously, the intelligent control system module, based on water quality data, instructs the automatic flocculant dosing module to precisely prepare and add PAC / PAM composite flocculant. In the flocculation reaction tank, slow stirring causes the fine particles to form larger flocs.

[0037] White water carrying flocs enters the multi-disc filtration module, where fibers and fillers are trapped to form a thick slurry, which is then sent to the fiber recovery liquid concentration module (such as a thickener) for further concentration. Subsequently, the thick slurry enters the filler modification and addition module, where modifiers such as cationic starch or polyacrylamide are added to improve the filler retention performance.

[0038] The filtrate generated by the multi-disc system enters the filtrate diversion module. Depending on the cleanliness level, the ultra-clean filtrate goes directly into the recycled water tank of the clean water reuse module, ready for reuse in areas with high water quality requirements, such as the paper machine spray. The clean filtrate may be partially returned to the production system or enter the next stage of treatment.

[0039] Low-concentration wastewater discharged from the system (such as some filtrate or cleaning wastewater) enters the inclined screen filtration and recovery module for final control. The influent first passes through the energy dissipation and water distribution module for uniform water distribution. The fibers are trapped by the inclined screen and collected and dewatered by the bottom spiral conveyor dewatering module. The dewatered fibers are sent to the recycled pulp preparation module, where they are mixed as needed with the modified pulp from the filler modification and addition module, and finally reused in the paper pulp system.

[0040] The intelligent control system module acts as the "brain," monitoring the entire process and controlling the cleaning and maintenance module to periodically clean the filter units. The generated chemical sludge is processed by the sludge treatment module. The effluent monitoring module ensures that the final effluent meets standards. The data storage and analysis module continuously optimizes operating strategies. The energy recovery module, chemical recycling module, and microbial inhibition module improve system performance from the perspectives of energy saving, consumption reduction, and hygiene, respectively. The system safety protection module ensures the safety of equipment and personnel throughout the entire process.

[0041] Example 2 The difference from Example 1 is that it also includes an advanced oxidation module connected after the inclined screen filtration and recovery module. This module can be activated when the presence of recalcitrant dissolved organic matter (DCS) or high color or toxicity is detected in the filtrate. Advanced oxidation technologies such as ozone, Fenton, and photocatalysis are used to deeply oxidize and decompose residual pollutants, ensuring higher quality recycled water or stable compliance of the final effluent.

[0042] Example 3 The difference from Example 1 is that it also includes a sludge resource utilization module, connected after the sludge treatment module. The characteristics of the dewatered and dried chemical sludge (mainly composed of inorganic fillers, fibers, and flocculants) are analyzed. Based on its composition, it is utilized as a raw material for low-grade cardboard fillers, building material additives (such as brick making), or soil conditioners, achieving "zero discharge" or high-value utilization of solid waste.

[0043] Test case I. Experimental Objective Compare the treatment effects of traditional white water treatment processes with those of the system in Example 1; Verify the deep processing capability of Example 2 (with the addition of an advanced oxidation module) for recalcitrant organic matter; Evaluate the sludge reduction and resource utilization benefits of Example 3 (with added sludge resource utilization module); A comprehensive analysis was conducted to identify the differences among the three implementation examples in terms of operating costs, reuse rates, and stability.

[0044] II. Test Conditions Source of white water: Mixed water sample from the wire mesh and pressing sections of a certain cultural paper production line. Initial water quality range: Chemical oxygen demand: 800–1200 mg / L; Total solids: 1200–1800 mg / L; Soluble and colloidal substances: 300–500 mg / L; pH value: 6.5–7.5; Flow rate: 100m 3 / h (continuous operation); Test period: Each group runs continuously for 168 hours (7 days); Comparison of process group settings: Control group: Traditional air flotation + inclined screen treatment process; Example 1: The system described in Example 1; Example 2 group: Example 1 + advanced oxidation module (ozone catalysis); Example 3 group: Example 1 + sludge resource utilization module (sludge brick making raw material); III. Test Results The water treatment effects are compared in the table below: The results of resource recycling and reuse are shown in the table below: The comparison of operating costs and energy consumption is shown in the table below: The system stability and automation level are shown in the table below: IV. Analysis of Experimental Results Example 1 vs. Control Group: Example 1 is significantly superior to traditional processes in terms of chemical oxygen demand and suspended solids removal rate, mainly due to the synergistic effect of multi-stage flocculation, multi-disc filtration, and inclined screen control. The recovery rate of fibers and fillers is increased by approximately 15–20%, and the clean water reuse rate is increased by approximately 30%. Operating costs are reduced by approximately 20–30%, and system stability is significantly improved.

[0045] Advantages of Example 2: The advanced oxidation module can further decompose recalcitrant dissolved organic matter, reduce the chemical oxygen demand of the effluent to below 60 mg / L, and significantly improve color, making it suitable for high-quality water reuse or scenarios with strict discharge standards. Although power consumption increases slightly, the reuse rate can be further improved to 90–95%.

[0046] Resource utilization benefits of Example 3: The sludge resource recovery module reduces sludge volume by approximately 40–50%, and the resource recovery products (such as brick additives) can generate additional revenue. The overall operating costs have been further reduced, and it aligns with the goal of a "zero waste" circular economy.

[0047] The role of intelligent control systems: All three sets of examples demonstrated good resistance to water quality fluctuations, high flocculant dosing accuracy, high degree of automation in cleaning and maintenance, and reduced manpower requirements.

[0048] The above description is only a preferred embodiment of this practice, but the scope of protection of this embodiment is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the scope of the technology disclosed in this embodiment, based on the technical solution and inventive concept of this embodiment, should be covered within the scope of protection of this embodiment.

Claims

1. A multi-stage white water treatment and reuse system for paper mills, characterized in that... The system includes a white water collection module, which is connected to an online water quality monitoring module. The online water quality monitoring module is connected to a pretreatment and conditioning module, which is connected to an automatic flocculant dosing module. The automatic flocculant dosing module is connected to a high-efficiency flocculation reaction module, which is connected to a multi-disc filtration module. The multi-disc filtration module is connected to a filtrate diversion module, which is connected to a fiber recovery liquid concentration module. The fiber recovery liquid concentration module is connected to a filler modification and addition module, which is connected to an inclined screen filtration and recovery module. The inclined screen filtration and recovery module is connected to an energy dissipation and water distribution module. The energy dissipation and water distribution module is connected to... It includes a screw conveyor dewatering module, which is connected to a reuse slurry preparation module. The reuse slurry preparation module is connected to an intelligent control system module. The intelligent control system module is connected to a cleaning and maintenance module. The cleaning and maintenance module is connected to a sludge treatment module. The sludge treatment module is connected to a clean water reuse module. The clean water reuse module is connected to an effluent detection module. The effluent detection module is connected to a data storage and analysis module. The data storage and analysis module is connected to an energy recovery module. The energy recovery module is connected to a reagent recycling module. The reagent recycling module is connected to a microbial inhibition module. The microbial inhibition module is connected to a system safety protection module.

2. The multi-stage treatment and reuse system for white water in a paper mill according to claim 1, characterized in that, The white water collection module is used to collect white water from various sections of the paper machine. The online water quality monitoring module is used to detect the chemical oxygen demand, total solids, dissolved and colloidal substances, dissolved matter, pH value and flow parameters of the white water in real time. The pretreatment adjustment module is used to adjust the flow rate and concentration of the white water, buffer water quality fluctuations, and provide stable conditions for subsequent treatment.

3. A multi-stage white water treatment and reuse system for paper mills according to claim 2, characterized in that, The automatic flocculant dosing module is used to dynamically calculate and add a flocculant solution composed of PAC and PAM based on water quality data; the high-efficiency flocculation reaction module is equipped with two or more mechanical stirring zones, so that suspended particles and colloidal substances in white water can fully contact and react with the flocculant to form easily separable flocs.

4. A multi-stage white water treatment and reuse system for paper mills according to claim 3, characterized in that, The multi-disc filtration module is used to intercept and recover flocculated fibers and filler flocs. The multi-disc filtration module includes fan blades with stainless steel filter screens. Each fan blade is divided into two stripping zones and equipped with an air valve to accelerate filtrate discharge and improve stripping efficiency. The filtrate diversion module divides the filtrate into ultra-clear filtrate and clear filtrate according to the solid content, and directs them to different reuse points. The fiber recovery liquid concentration module further concentrates the recovered concentrated fiber pulp.

5. A multi-stage white water treatment and reuse system for paper mills according to claim 4, characterized in that, The filler modification and addition module adds specific polymeric modifying chemicals to the concentrated slurry, which promotes the more firm adhesion of the fine fillers and colloidal substances in the slurry to the fiber surface; the inclined screen filtration and recovery module is used to treat the effluent or other low-concentration wastewater after multi-disc filtration, and further recover the residual fibers therein.

6. A multi-stage white water treatment and reuse system for paper mills according to claim 5, characterized in that, The energy dissipation and water distribution module includes a water distribution tank, an energy dissipation wall, and a water distribution trough, which are used to distribute the incoming water evenly and stably on the inclined wire mesh; the screw conveyor dewatering module is used to collect the fibers that slip off the inclined wire mesh and perform preliminary dewatering; the recycled pulp preparation module mixes and prepares the modified pulp with the fibers recovered from the inclined wire mesh according to the process requirements and sends it back to the papermaking workshop for reuse.

7. A multi-stage white water treatment and reuse system for paper mills according to claim 6, characterized in that, The intelligent control system module is based on programmable logic controller and Internet of Things technology to realize centralized monitoring, automatic adjustment and optimization of the entire system's operating parameters; the cleaning and maintenance module automatically performs high-pressure water flushing of the multi-disc filter and inclined screen, as well as backflushing of the system pipelines; the sludge treatment module concentrates, filters and dries the generated chemical sludge.

8. A multi-stage white water treatment and reuse system for paper mills according to claim 7, characterized in that, The clean water reuse module stores and pumps ultra-clean filtrate and clean filtrate that meet the process requirements to different water usage points in the papermaking workshop for reuse; the effluent detection module monitors the chemical oxygen demand and suspended solids of the effluent online.

9. A multi-stage white water treatment and reuse system for paper mills according to claim 8, characterized in that, The data storage and analysis module stores all operation and monitoring data and performs energy efficiency analysis, fault prediction, and process optimization suggestions through built-in algorithms; the energy recovery module recovers energy by utilizing the residual pressure or heat of the fluid during the treatment process; the reagent recycling module collects and treats wastewater containing incompletely reacted flocculants, recovers the effective components, and reuses them in the automatic flocculant dosing module.

10. A multi-stage white water treatment and reuse system for paper mills according to claim 9, characterized in that, The microbial inhibition module is installed in the white water collection tank or the clean water reuse tank, and uses an ultraviolet irradiator or a low-dose ozone generator to inhibit the growth of microorganisms and putrefaction in the system; the system safety protection module includes a pressure sensor, a leak detection sensor, an overload protector and an emergency stop button to ensure the safe operation of the system.

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