A circulating water treatment and purification system based on turbidity monitoring

Abstract

This invention relates to the field of industrial water treatment and intelligent control technology, specifically to a circulating water treatment and purification system based on turbidity monitoring and linkage. The system includes: a data acquisition module, a parameter calculation module, a linkage control module, a cross-section adaptive module, and a closed-loop feedback module. It collects influent flow rate, influent turbidity, vertical depth turbidity at at least two preset water depths in the sedimentation unit, and influent pressure data from the downstream deep filtration unit. It calculates the basic chemical dosage, vertical turbidity settling gradient, and cross-section load transfer index. Based on this, it controls chemical dosing and sludge discharge, and lowers the target effluent turbidity setpoint when the turbidity continuously exceeds the warning level. It dynamically corrects the preset settling threshold based on the deviation between the sedimentation unit effluent turbidity and the target. This invention achieves linkage control between the pretreatment section and the downstream deep filtration section, reducing reliance on manual experience and improving the overall stability of the system.

Description

Technical Field

[0001] This invention relates to the field of industrial water treatment and intelligent control technology, specifically to a circulating water treatment and purification system based on turbidity monitoring linkage. Background Technology

[0002] Mine water recycling treatment technology is a common method for water resource reuse and emission reduction control in mining areas. It typically removes suspended solids and fine coal slurry from mixed mine water in goaf areas through processes such as chemical coagulation, sedimentation separation, and subsequent deep filtration. It can also monitor influent flow rate, influent turbidity, or effluent indicators online, and has a certain continuous treatment capacity and engineering applicability. With the increasing disturbance of mine production and the application of downstream membrane concentration and other advanced treatment units, the shortcomings of traditional circulating water treatment methods have gradually become apparent. When the turbidity of the incoming water fluctuates rapidly and the proportion of fine particles changes significantly, the existing control methods still rely on fixed proportion of chemical addition, single effluent index control, or manual timed sludge removal. These methods are difficult to reflect the actual settling state in the sedimentation unit in a timely manner, and are also difficult to take into account the clogging load of the downstream filtration unit. This results in low effluent stability, high chemical consumption, and a tendency to cause subsequent filtration performance degradation. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a circulating water treatment and purification system based on turbidity monitoring linkage. Specifically, the technical solution of this invention includes: The system includes a dosing actuator and a sludge discharge actuator. The dosing actuator includes a variable frequency metering pump and a dosing pipeline, the variable frequency metering pump being connected to the circulating water treatment unit via the dosing pipeline. The sludge discharge actuator includes a sludge discharge pipeline located at the bottom of the sedimentation unit and a pneumatic sludge discharge valve installed on the sludge discharge pipeline. It also includes: The data acquisition module is used to collect influent flow rate and turbidity, collect vertical depth turbidity at at least two preset water depths in the sedimentation unit, and collect influent pressure data of the downstream depth filtration unit. The parameter calculation module is used to obtain the preset initial reagent ratio coefficient and target effluent turbidity setpoint; calculate the basic dosage by multiplying the influent flow rate and influent turbidity with the preset unit turbidity dosage; calculate the vertical turbidity sedimentation gradient based on vertical depth turbidity; and calculate the cross-section load transfer index based on influent pressure data. The linkage control module is configured as follows: if the settling gradient is less than the preset settling threshold, the reagent ratio coefficient is increased to generate a dosing control command, which is combined with the basic dosing amount to control the dosing actuator; otherwise, the current ratio coefficient is maintained; if the vertical depth turbidity of the bottom water is greater than the preset sludge concentration threshold, the sludge discharge actuator is controlled to start sludge discharge; otherwise, sludge discharge is turned off. The cross-section adaptive module is configured as follows: if the load transfer index is greater than the preset warning value and continues to exceed the preset warning time, the target effluent turbidity setting value is reduced according to the preset attenuation coefficient; otherwise, the setting value is maintained. The closed-loop feedback module is used to dynamically correct the preset sedimentation threshold based on the deviation between the effluent turbidity and the set value.

[0004] Preferably, the parameter calculation module includes a gradient calculation unit and a load calculation unit. The gradient calculation unit is used to obtain the vertical depth turbidity at the first preset water depth and the vertical depth turbidity at the second preset water depth within the sedimentation unit, calculate the difference between the vertical depth turbidity at the first preset water depth and the vertical depth turbidity at the second preset water depth, and after determining that the absolute value of the height difference between the first preset water depth and the second preset water depth is greater than or equal to a preset effective difference, divide the difference by the absolute value of the height difference to generate a vertical turbidity sedimentation gradient. The load calculation unit is used to extract the time partial derivative of the continuous influent pressure data obtained based on a preset sampling time interval to generate a cross-section load transfer index.

[0005] Preferably, the parameter calculation module is also used to extract the time partial derivative of the influent turbidity to calculate the influent turbidity change rate; the linkage control module is also used to generate a feedforward dosing compensation instruction and superimpose it on the dosing control instruction when the influent turbidity change rate is greater than the preset mutation threshold, and not generate a feedforward dosing compensation instruction when the influent turbidity change rate is not greater than the preset mutation threshold.

[0006] Preferably, the closed-loop feedback module is used to calculate the difference between the effluent turbidity and the target effluent turbidity set value as the turbidity deviation value. The turbidity deviation value is input into a preset proportional-integral-derivative (PID) controller. The PID controller outputs the sum of the proportional term, integral term, and derivative term, and adds it to the set reference coefficient constant to generate a floating correction coefficient. The correction coefficient is then multiplied by a preset settling threshold to generate an updated preset settling threshold.

[0007] Preferably, the system also includes a degradation protection module; when the vertical turbidity sedimentation gradient is less than the preset failure threshold and the duration exceeds the preset failure duration, the suspended solids sedimentation characteristics are determined to be faulty, triggering the degradation protection mechanism, switching the dosing control command to the preset fixed ratio dosing mode, and outputting a manual intervention alarm signal; when the failure determination conditions are not met, the current control logic of the linkage control module is maintained.

[0008] Preferably, the linkage control module further includes a signal conversion unit, which converts the dosing control command into an analog signal to control the motor speed of the dosing actuator; and converts the sludge discharge start command or sludge discharge stop command into a digital signal to control the valve opening degree and opening duration of the sludge discharge actuator.

[0009] Preferably, the data acquisition module collects the influent flow rate and influent turbidity through an electromagnetic flow meter and an online turbidity meter installed in the influent pipe of the circulating water treatment unit; collects the vertical depth turbidity through an array of submerged turbidity sensors deployed on the inner wall of the sedimentation unit; and reads the influent pressure data from the programmable logic controller of the downstream depth filtration unit through a communication protocol.

[0010] Preferably, the system is applied to a mine water treatment scenario; the circulating water in the circulating water treatment unit includes mixed mine water from the goaf; the downstream deep filtration unit includes a membrane concentration system; and the reagent ratio coefficient is used to adjust the dosage of polyacrylamide.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention can incorporate influent load, sedimentation state in the pool, downstream filtration load and final effluent quality into the same control closed loop, which has the advantages of reducing the lag of fixed-ratio dosing and manual timed sludge removal, improving effluent stability and reducing the risk of downstream filtration performance degradation. 2. The present invention can convert whether effective stratified sedimentation has formed in the sedimentation unit and whether the downstream filtration unit is clogging rapidly into engineering parameters that can be continuously monitored, which has the advantages of improving the accuracy of sedimentation state identification and the ability to judge the precursors of downstream clogging. 3. This invention can enhance the dosing of chemicals in advance by taking advantage of the early signs of sudden changes in upstream water flow before the feedback from the sedimentation tank has appeared. It has the advantages of shortening the process response time, reducing the control lag of the large lag sedimentation process, and reducing the impact of sudden high turbidity on subsequent processes. 4. This invention enables the settling threshold to be dynamically adjusted according to the actual effluent effect, rather than relying on a fixed empirical value in the long term. It has the advantages of continuously adapting to changes in water temperature, coal slime properties and reagent batches, and improving long-term operational stability. 5. This invention can provide a clear safety exit path for the system when the key settlement criteria lose their representativeness, and has the advantage of avoiding continuous adjustment of the erroneous closed loop that leads to sludge runaway, uncontrolled effluent discharge and damage to the downstream membrane system; 6. This invention can establish a complete data acquisition link covering the water inlet, the stratified end in the pool and the downstream filtration end. It has the advantages of ensuring continuous availability of multi-source monitoring data, reducing the difficulty of implementing new independent acquisition links, and providing a reliable information foundation for cross-section linkage control. Attached Figure Description

[0012] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of a circulating water treatment and purification system based on turbidity monitoring linkage provided in an embodiment of this application. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0014] A circulating water treatment and purification system based on turbidity monitoring linkage includes a dosing actuator and a sludge discharge actuator. The dosing actuator includes a variable frequency metering pump and a dosing pipeline, the variable frequency metering pump being connected to a circulating water treatment unit via the dosing pipeline. The sludge discharge actuator includes a sludge discharge pipeline located at the bottom of the sedimentation unit and a pneumatic sludge discharge valve installed on the sludge discharge pipeline. The system also includes: The data acquisition module is used to collect influent flow rate and turbidity, collect vertical depth turbidity at at least two preset water depths in the sedimentation unit, and collect influent pressure data of the downstream depth filtration unit. The parameter calculation module is used to obtain the preset initial reagent ratio coefficient and target effluent turbidity setpoint; calculate the basic dosage by multiplying the influent flow rate and influent turbidity with the preset unit turbidity dosage; calculate the vertical turbidity sedimentation gradient based on vertical depth turbidity; and calculate the cross-section load transfer index based on influent pressure data. The linkage control module is configured as follows: if the settling gradient is less than the preset settling threshold, the reagent ratio coefficient is increased to generate a dosing control command, which is combined with the basic dosing amount to control the dosing actuator; otherwise, the current ratio coefficient is maintained; if the vertical depth turbidity of the bottom water is greater than the preset sludge concentration threshold, the sludge discharge actuator is controlled to start sludge discharge; otherwise, sludge discharge is turned off. The cross-section adaptive module is configured as follows: if the load transfer index is greater than the preset warning value and continues to exceed the preset warning time, the target effluent turbidity setting value is reduced according to the preset attenuation coefficient; otherwise, the setting value is maintained. The closed-loop feedback module is used to dynamically correct the preset sedimentation threshold based on the deviation between the effluent turbidity and the set value.

[0015] This embodiment provides a circulating water treatment and purification mechanism based on turbidity monitoring linkage, such as... Figure 1 As shown; specifically, this mechanism is deployed in the first phase of the renovation line of the mine water treatment plant in the Burtai mining area, and the treatment target is mixed mine water in the goaf area. The process flow includes a circulating water pretreatment unit, a sedimentation unit, a downstream deep filtration unit, and a subsequent reuse stage. The main scenario is set during the night shift of mine production. The turbidity of the water coming down from the mine fluctuates beyond the preset allowable range due to mining disturbances. The plant requires that the pre-treated water not only meet the suspended solids control requirements of this section, but also not bring continuous clogging load to the subsequent filtration and membrane concentration units. Specifically, the data acquisition module does not only collect single-point data from the inlet, but simultaneously acquires three data sources with different physical meanings. First, the inlet flow rate and inlet turbidity reflect the total load of suspended solids entering the system per unit time, which is the direct basis for basic dosing. Second, the turbidity at different water depths in the sedimentation unit reflects the vertical distribution of flocs, which can characterize whether the flocs have formed sufficient particle size and settled downwards. Third, the inlet pressure data of the downstream deep filtration unit reflects whether the subsequent filtration resistance is increasing, which can indirectly reveal whether fine suspended solids in the pretreated effluent are being transferred across sections and causing blockages. In engineering, the parameter calculation module is responsible for converting dispersed monitoring data into quantitative process state parameters that drive control. The basic dosage is determined by the influent flow rate, influent turbidity, and preset unit turbidity dosage. Essentially, it provides an initial dosing level based on the instantaneous influent load. The preset unit turbidity dosage represents the standard reagent mass required to treat a unit volume and a unit turbidity of water. The vertical turbidity settling gradient is used to describe the degree of turbidity stratification between the upper and middle clear zones and the lower mud-water mixing zone within a sedimentation unit. If the gradient is greater than the preset settling threshold, it usually means that flocs have formed and continue to settle, and the upper water tends to become clear. If the gradient is less than the preset settling threshold, it means that a large number of fine particles are still suspended between the layers, and the coagulation or flocculation effect is insufficient. The cross-section load transfer index does not directly assess the internal state of the sedimentation unit, but rather observes whether the downstream pressure change is accelerating. A continuous increase in pressure indicates that the filtration unit is trapping fine particles more quickly. Although these particles may not have caused the current effluent index to exceed the limit immediately, they have already begun to consume the downstream filtration capacity. The linkage control module forms a dual-channel control based on this; one channel is the dosing linkage: when the settling gradient is lower than the preset settling threshold, it indicates that the floc settling performance is insufficient. The system increases the ratio based on the existing reagent ratio coefficient to allow the flocculant to bridge and adsorb more fully, thereby promoting the aggregation of fine particles and improving the settling effect; if the settling gradient is maintained within a reasonable range, the current reagent ratio is maintained to avoid excessive dosing. Another channel is sludge discharge linkage: when the turbidity at the bottom water depth rises above the sludge concentration threshold, it indicates that the sludge layer at the bottom of the sedimentation unit has accumulated to a state greater than the preset sludge concentration threshold. If it continues to stagnate, it may re-enter the supernatant zone due to local disturbance, air bubble entrainment, or sludge floating. At this time, the sludge discharge actuator is activated; if the bottom concentration is still low, the sludge discharge is turned off to reduce effective water loss. The cross-section adaptive module addresses the issue that while the water quality indicators of the current section meet the standards, the performance of downstream filtration components continues to decline due to the accumulation of fine particles. In mine water treatment, relying solely on the single turbidity limit of the pretreated effluent can easily overlook the fact that downstream filtration units are particularly sensitive to fine particles. Therefore, when the cross-section load transfer index continuously exceeds the warning condition, the system actively lowers the target effluent turbidity setpoint. This action is equivalent to raising the operating requirements of the pretreatment section, so that fine particles are intercepted upstream earlier and downstream blockage is reduced; if the load transfer index does not continue to exceed the limit, the original target is maintained to avoid excessive pursuit of low turbidity, which may lead to overload of the dosing system or cause process disturbance. The closed-loop feedback module makes the whole mechanism independent of fixed empirical values; the turbidity of the sedimentation unit effluent is the final test of the current control results; if the effluent turbidity is higher than the target for a long time, it indicates that the original sedimentation threshold is too lenient, and the system can gradually increase its sensitivity to insufficient sedimentation; if the effluent turbidity is stable and better than the target for a long time, the threshold can be set too harshly; thus, the sedimentation threshold is dynamically corrected according to the operating status, rather than being fixed to a manual empirical value for a long time. It should be noted that the preset settling threshold, preset sludge concentration threshold, preset warning value, preset warning duration, preset attenuation coefficient, preset initial reagent ratio coefficient, and preset mutation threshold involved in this system are all initialized by the system based on historical mine water operation data or empirical values ​​from on-site sampling tests, and are pre-stored in the storage module of the control system. In response to abnormal system conditions, if a water depth sensor goes offline for a short period of time, the system can temporarily use the remaining effective water depth combinations to maintain the settlement trend judgment and issue maintenance prompts for the missing measuring points; if the inlet pressure data communication of the downstream filter unit is interrupted, cross-section adaptive control will be suspended, and only the local linkage of chemical dosing and sludge discharge will be retained; if the inlet flow meter fluctuates abnormally and its fluctuation range exceeds the process allowable range, the basic chemical dosing will not be updated in this cycle, and the control output of the previous stable cycle will be maintained first to avoid system disturbance caused by accidental chemical dosing; Specifically, during a certain period of the night shift in the Burtai mining area, the turbidity of the mixed mine water in the goaf increased rapidly due to local coal slime disturbance. The system increased the basic dosing level based on the influent flow rate and turbidity. At the same time, it was detected that the turbidity stratification between the middle and lower layers in the sedimentation unit was not obvious, indicating that the formed flocs were too fine and the sedimentation was insufficient. Therefore, the flocculant ratio was further increased. After a period of hydraulic retention, the turbidity of the upper effluent gradually decreases. At the same time, if the inlet pressure of the downstream deep filtration unit continues to rise, the system will further tighten the pretreatment target effluent turbidity from the normal control level to force the front end to remove fine suspended solids more fully. If the vertical depth turbidity of the water at the bottom of the sedimentation unit is close to the upper limit of sludge accumulation, the system will simultaneously open the sludge discharge valve to release high-concentration sludge. The purpose of this step is to incorporate the influent load, sedimentation status in the pool, downstream blockage trend, and final effluent quality into the same control closed loop, thereby achieving linkage control between the pretreatment section and the downstream deep filtration section, reducing reliance on manual experience, and improving the overall stability of the mine water system.

[0016] Furthermore, the parameter calculation module includes: The gradient calculation unit is used to obtain the vertical depth turbidity of the first preset water depth and the vertical depth turbidity of the second preset water depth in the sedimentation unit, calculate the difference between the vertical depth turbidity of the first preset water depth and the vertical depth turbidity of the second preset water depth, and after determining that the absolute value of the height difference between the first preset water depth and the second preset water depth is greater than or equal to the preset effective difference, divide the difference by the absolute value of the height difference to generate the vertical turbidity sedimentation gradient. The load calculation unit is used to extract the time partial derivative of continuous inlet pressure data obtained based on a preset sampling time interval, so as to generate the cross-section load transfer index.

[0017] This embodiment provides a parameter refinement calculation mechanism. Specifically, in the aforementioned main scenario, knowing only that the sedimentation unit has high or low turbidity is insufficient to determine whether the flocs are effectively settling or finely suspended throughout the entire pool. Similarly, knowing only that the current value of the influent pressure data is high or low is insufficient to determine whether the blockage is worsening. Therefore, this embodiment further decomposes the turbidity stratification in the pool and the downstream pressure change into two state variables with greater process discriminative power. Specifically, the gradient calculation unit selects the first and second preset water depths in the sedimentation unit. These two depths can be located at the lower edge of the upper clear zone and the transition zone between the middle and lower layers, or near the mud-water interface between the middle and bottom layers, respectively. This unit does not focus on the absolute turbidity at a single point, but rather on the correspondence between the turbidity drop and the height difference between different water layers. Its physical meaning is as follows: if the flocs form and settle smoothly, the upper layer will become clearer first and the lower layer will retain more particles, so there will be obvious stratification between water layers; if the particles are suspended for a long time or are stirred and mixed, the turbidity at different water depths will be similar and the gradient will tend to weaken; taking the absolute value of the difference is to be compatible with the order of sensors under different installation positions and different pool types, so that the system always extracts the core state of the strength of stratification, and is not affected by the direction of the measuring point number; The load calculation unit extracts the time-varying trend from the downstream inlet pressure data. Its engineering significance is that the clogging of the filter unit often manifests first as an increase in the rate of pressure rise, rather than an immediate exceedance of the absolute pressure value at a certain moment. In other words, the pressure change rate is more suitable than the instantaneous pressure value for identifying the process of clogging. If the change rate is consistently large, it indicates that more fine particles that are difficult to settle are penetrating the pretreatment upstream and being intercepted downstream. If the pressure is generally stable, it indicates that the pretreatment's particle burden on the downstream is at an acceptable level. In practical engineering implementation, extracting the time partial derivative does not involve solving the analytical derivative of a continuous function, but rather performing differential processing on the discrete pressure data acquired periodically by the system. Specifically, the system acquires the inlet pressure data at the current sampling time and the inlet pressure data at the previous sampling time, calculates the difference between the two, and then divides it by the system's preset sampling time interval to obtain the single-step rate of change. Since field pressure sensors are often affected by transient water hammer or water pressure fluctuations caused by the start and stop of pumps and valves, a moving average filter can be applied to multiple consecutive single-step change rates. The smoothed result is used as the cross-section load transfer index. Through this data flow rule, the abstract time partial derivative is transformed into a stable process monitoring parameter with strong anti-interference ability. To facilitate understanding, a simplified explanation can be provided: Assuming the turbidity difference between the measuring points corresponding to the first and second preset water depths is greater than a preset difference threshold, and the installation height distance between the two is fixed, the system will determine that the stratification is clear; assuming the readings of the two measuring points are close for a long period, even if the absolute values ​​do not reach the over-limit warning value, it indicates that the flocs have not formed an effective settling zone; furthermore, if the influent pressure data rises slowly over multiple consecutive sampling cycles, the system can consider it as normal filter layer load accumulation; if it rises continuously in a short period of time, it is closer to an abnormal blockage precursor. As a backup protection mechanism, if the difference between the two selected water depths is less than the preset effective difference, it is easy to amplify local disturbances and measurement noise. In this case, it is advisable to set the measurement point for calculation at a representative interlayer distance. If the pressure data shows a spike at a certain moment due to the start-up and shutdown of the pump or the switching of the valve position, obvious non-process-related sudden changes can be eliminated or the confirmation can be delayed to prevent the equipment operation disturbance from being misjudged as a continuous blockage trend. Specifically, two submerged turbidity sensors, one meter and two meters below the water surface, were installed on the inner wall of the sedimentation unit in the Burtai mining area, and another bottom sensor was installed near the mud-water interface at the bottom of the pool. During operation, the turbidity difference between the upper and middle layers suddenly decreased, indicating that the flocs failed to settle quickly. At the same time, the influent pressure data obtained from the cross-section showed a monotonically increasing trend over several consecutive sampling periods, indicating that fine particles had begun to move downstream. Based on this, the system could identify both the deterioration of sedimentation inside the sedimentation unit and the amplification of the load in the cross-section. The purpose of this step is to transform the effectiveness of settlement and the acceleration of blockage, which were originally difficult to observe directly, into engineering parameters that can be continuously monitored, thereby enabling more targeted chemical dosing adjustments and cross-section collaborative scheduling.

[0018] Furthermore, the parameter calculation module is also used to extract the time partial derivative of the influent turbidity to calculate the influent turbidity change rate; the linkage control module is also configured to: if the influent turbidity change rate is greater than the preset mutation threshold, generate a feedforward dosing compensation instruction and superimpose it on the dosing control instruction; otherwise, do not generate a feedforward dosing compensation instruction.

[0019] This embodiment provides a feedforward dosing compensation mechanism. Specifically, in the aforementioned linkage mechanism, the settling gradient can reflect the settling state of flocs in the pool, but the sedimentation pool itself has a hydraulic residence time. When there is a violent fluctuation at the inlet, relying solely on the feedback within the pool may be too late in time. Especially in the mine water scenario, the turbidity of the incoming water may suddenly increase in a short period of time due to fault penetration, mining disturbance, or local drainage switching at the coal face. To cope with this upstream change, this embodiment adds feedforward compensation in addition to the original feedback control. Specifically, the rate of change of influent turbidity does not describe the absolute level of the raw water suspended solids concentration, but rather the instantaneous rate at which the raw water suspended solids concentration increases. When this rate of change is large, it usually means that the suspended particulate load is increasing rapidly, but this change has not yet been transmitted to each layer of the sedimentation tank and the effluent end. If the chemical is adjusted only after the settling gradient deteriorates or the effluent deteriorates, it is often too late. Therefore, after the system detects that the sudden change in influent turbidity exceeds the preset sudden change threshold, it adds a portion of feedforward chemical compensation in advance, so that the coagulation and flocculation reactions have a higher chemical preparation degree from the influent end, thereby shortening the process response time. To clearly define the acquisition logic of this feedforward parameter, the time partial derivative of the influent turbidity is extracted and converted into discrete differential operation within the industrial controller. The specific process is as follows: continuously cache the influent turbidity data of historical periods, subtract the influent turbidity of the previous historical time before the set time window from the influent turbidity at the current time, and divide by the span of the time window. Based on this, if there is numerical distortion caused by the automatic cleaning action of the turbidity meter, it will be removed when calculating the time partial derivative and the partial derivative value of the previous effective cycle will be maintained. For example, when the turbidity of the influent surges from 100 NTU to 300 NTU in 5 minutes, the calculated time partial derivative is 40 NTU per minute. If this value exceeds the mutation threshold, such as 20 NTU per minute, the mutation is determined to have occurred, and a feedforward dosing compensation command will be output. This compensation is superimposed on the original dosing control command, rather than replacing the basic dosing and gradient feedback. The reason for this design is that the fluctuations in the influent water in mine water treatment include both changes in total volume and rapid changes in water quality characteristics. The basic dosing is responsible for matching the overall load, the gradient feedback is responsible for correcting the settling state, and the feedforward compensation is specifically designed to deal with rapid disturbances. The superposition of the three can take into account both normal operating conditions and minimize the fluctuations in effluent water under abnormal operating conditions. As a response mechanism to local faults, if the influent turbidity is high but changes gradually, the system does not need to activate feedforward compensation to avoid mistaking stable high turbidity for a sudden anomaly. If the influent turbidity meter produces a short-term spike due to cleaning cycle, bubble interference, or sampling head contamination, the feedforward output should be suppressed when the spike is identified as not being persistent, and only normal control should be maintained. If influent turbidity data is missing, the system should suspend feedforward compensation to avoid blindly adding reagents based on unreliable input. Specifically, during the night shift operation in the Burtai mining area, local underground mining caused the incoming water to jump from a normal turbidity state to a high turbidity state in a short period of time; at this time, the water layers in the sedimentation tank did not immediately show obvious changes, but the rate of change of the turbidity of the influent had already exceeded the abrupt change criterion. The system then superimposed feedforward compensation on the existing dosing instructions, which enhanced the dosing of coagulants and flocculants in advance. After a settling and retention cycle, although the influent water had deteriorated significantly, the fluctuation range of effluent turbidity was controlled within a small range, and no synchronous impact occurred in the downstream filtration unit. The purpose of this mechanism is to intervene and control the situation in advance by utilizing the early warning information of upstream disturbances, thereby achieving a pre-response to the large-delay sedimentation process and reducing the impact of sudden changes in mine water on subsequent work sections.

[0020] Furthermore, the closed-loop feedback module is specifically used for: calculating the difference between the effluent turbidity and the target effluent turbidity setpoint as the turbidity deviation value; inputting the turbidity deviation value into a preset proportional-integral-derivative (PID) controller; calculating the sum of the proportional, integral, and derivative terms through the output of the PID controller, adding it to the set reference coefficient constant to generate a floating correction coefficient, and multiplying the correction coefficient by the preset settling threshold to generate an updated preset settling threshold.

[0021] This embodiment provides a self-correcting mechanism for the settling threshold. Specifically, in the aforementioned scheme, the settling threshold is used to determine the degree to which stratification in the pool can be considered effective. If this threshold is fixed for a long time, it is easily affected by seasonal changes, water temperature changes, changes in coal slime properties, and changes in reagent batches, resulting in the same threshold no longer being suitable under different operating conditions. Therefore, this embodiment uses the final result of effluent turbidity to perform closed-loop tuning of the settling threshold. Specifically, the deviation between the effluent turbidity and the target effluent turbidity setpoint represents the distance between the current control effect and the process target; this deviation is input into the proportional-integral-derivative controller to take into account three different types of process phenomena: the proportional action reflects the immediacy of the current deviation and is suitable for rapid response to current effluent deterioration; The integral action reflects the cumulative deviation and is suitable for correcting long-term, slight deviations that persist; the derivative action reflects the trend of deviation changes and is suitable for suppressing the deviation before the effluent deteriorates; the correction coefficient output by the regulator is then applied to the settling threshold, giving the threshold an adaptive capability. To ensure the feasibility of the above adjustment process, the process of the regulator outputting the correction coefficient is broken down in detail: the system uses the turbidity deviation value of the current cycle to participate in proportional calculation, error accumulation integral calculation, and differential calculation of the difference between adjacent deviations; the above calculations are based on the proportional coefficient, integral coefficient, and differential coefficient preset by the system; the sum of the proportional term, integral term, and differential term is added to the reference coefficient constant set to 1.0, thereby generating a floating correction coefficient centered at 1.0; at the same time, to prevent threshold loss of control due to extreme abnormalities in effluent turbidity, the system sets upper and lower limit ranges for the correction coefficient, for example, from 0.8 to 1.2; For example, if the turbidity of the effluent exceeds the set value for a long period of time due to water quality changes, but remains within the preset slight deviation range, since the deviation value is always positive, it will continuously accumulate through integral action. The total adjustment output of the regulator is assumed to be 0.05, which is added to the reference coefficient of 1.0 to obtain the correction coefficient of 1.05. Specifically, the system will multiply the original preset sedimentation threshold of, for example, 10.0 by 1.05 and update it to 10.5. Because the sedimentation threshold is increased, the linkage control module will be more likely to determine that the current gradient is lower than the threshold, and thus execute the action of increasing the dosage ratio earlier, thereby realizing closed-loop dynamic control. The purpose of this design is that the sedimentation threshold is no longer an empirical value that remains unchanged for a long time after being set manually once, but rather a criterion that is more suitable for the current water quality, the current batch of chemicals, and the current pool type as the actual effluent performance gradually approaches it. For example, if the effluent turbidity is consistently higher than the target, it means that the system may not be sensitive enough to the identification of insufficient sedimentation. After correction, the threshold can be adjusted to a more stringent direction. Conversely, if the effluent is consistently better than the target and the system dosage is too high, the threshold can be appropriately returned to a more balanced control range to avoid excessive intervention. As an abnormal handling logic, if the effluent turbidity meter is in backwashing or maintenance mode, the threshold will not be updated temporarily and the threshold of the previous cycle will be maintained; if the effluent turbidity rises abnormally for a short time but is accompanied by downstream valve switching, sludge discharge action or sampling head disturbance, the threshold can be corrected after confirmation to avoid the control parameters being introduced into the error by occasional noise; if the regulator output exceeds the process allowable boundary, the correction coefficient will be limited to a safe range to prevent the threshold from being distorted and drifting. Specifically, after several days of continuous operation in the Burtai mining area, the proportion of fine coal slime in the mine water increased. Although the total turbidity of the influent did not increase significantly, the floc formation rate slowed down, resulting in the effluent turbidity deviating from the target value. The system identified this deviation through closed-loop feedback and gradually tightened the settling threshold, enabling the linkage control module to identify insufficient settling earlier and increase the ratio correction. The effluent turbidity returned to near the target, instead of relying on repeated manual adjustments by operators for a long time. The purpose of this mechanism is to allow the settlement criterion to be automatically corrected according to the actual operating effect, thereby achieving continuous adaptation to the complex fluctuations of mine water and improving long-term operational stability.

[0022] Furthermore, the system also includes a degradation protection module, configured as follows: if the vertical turbidity sedimentation gradient is less than the preset failure threshold and the duration exceeds the preset failure duration, the suspended solids sedimentation characteristics are determined to be faulty, triggering the degradation protection mechanism, switching the dosing control command to the preset fixed ratio dosing mode, and outputting a manual intervention alarm signal; otherwise, the current control logic of the linkage control module is maintained.

[0023] This embodiment provides a degradation protection mechanism. Specifically, the aforementioned linkage scheme is based on an important premise, namely, that identifiable turbidity stratification can be formed between different water layers in the sedimentation tank, thereby inferring the floc settling status. However, under extreme conditions, this premise may not hold. For example, when a large amount of ultrafine colloidal coal slime is mixed into mine water, the particle size is extremely small, the specific gravity difference is weak, and the electrical properties are stable, making it easy to remain uniformly suspended in the water for a long time. Even if the dosing system is continuously adjusted, the turbidity gradient between different water layers may still approach zero for a long time. Continuing to rely on this parameter may lead to miscontrol. Therefore, this embodiment is equipped with failure identification and degradation protection. Specifically, when the vertical turbidity settling gradient is lower than the preset failure threshold and this state continues for more than the preset failure duration, the system determines that it is not a temporary lack of flocculation, but that the current suspended solids settling mechanism has deviated from the conventional process assumptions. The duration condition is very critical here, because a short-term low gradient may only be caused by influent disturbance, backmixing in the pool, or sludge discharge. Only when effective stratification cannot be formed for a long time is it closer to the failure of settling characteristics. Upon triggering, the system will switch the dosing control to the preset fixed ratio dosing mode and issue a manual intervention alarm, prompting the operator to check the water composition, chemical type, dosing point, stirring conditions, and whether temporary emergency measures such as bypassing or enhanced pre-oxidation are needed. The significance of a fixed-ratio dosing mode is not optimal control, but rather a safety net. When key parameters are distorted, retaining a conservative dosing scheme that has been validated by historical operating conditions is usually more effective than continuing to rely on erroneous feedback in preventing sludge overflow, uncontrolled effluent, and sudden damage to downstream membrane systems. Alarm signals promptly transmit process anomalies from the automation layer to the management layer, preventing the system from operating without intervention for extended periods under failure conditions. As an anomaly handling logic, if the low gradient is only caused by sludge adhering to the surface of a certain turbidity sensor, resulting in distorted readings, the system can combine data from other layers and sensor self-diagnostic information to first determine whether it is a measurement fault; if there is only a short-term anomaly and the duration condition is not met, the system will not enter the degradation mode to avoid frequent switching of control strategies; in the degradation mode, if the subsequent water layer stratification recovers and is confirmed after a period of observation, the system can be manually confirmed or return to the linkage control mode according to the preset recovery logic. Specifically, during the mining of a specific coal seam in the Burtai mining area, a large amount of ultrafine colloidal coal slime was carried in the mixed mine water in the goaf. The system continuously monitored that the turbidity difference between the water layers in the sedimentation tank was extremely small, and this state continued, and the turbidity of the effluent began to show signs of instability. At this time, the system stopped further fine-tuning the ratio according to the sedimentation gradient and switched to the preset high-ratio fixed dosing mode, and sent a manual intervention alarm to the central control room. After the operators arrived, they found that the original flocculant had decreased compatibility with this batch of incoming water. The system was restored to normal by manually changing the reagent combination and cleaning the sampling points. The purpose of this mechanism is to provide a clear safety net for the system when key criteria lose their representativeness, thereby avoiding process loss of control caused by error loops and ensuring the continuous operation of the mine water treatment line.

[0024] Furthermore, the linkage control module also includes a signal conversion unit, used to: convert the dosing control command into an analog signal to control the motor speed of the dosing actuator; and convert the sludge discharge start command or sludge discharge stop command into a digital signal to control the valve opening degree and opening duration of the sludge discharge actuator.

[0025] This embodiment provides a control command execution mechanism; specifically, if the dosing control command and sludge discharge control command in the aforementioned scheme only remain at the logic layer, they still cannot directly act on the field equipment; therefore, this embodiment adds a signal conversion unit so that the process decision can be accurately received by the actuators such as the frequency conversion metering pump and the pneumatic sludge discharge valve. Specifically, dosing control typically corresponds to continuously adjustable output requirements. Different influent loads, floc formation states, and downstream protection requirements necessitate that metering pumps have smooth speed regulation capabilities, rather than simply starting and stopping. Therefore, the signal conversion unit converts dosing control commands into analog signals, enabling continuous changes in the metering pump motor speed, stroke frequency, or inverter output. Its physical meaning lies in converting the required increase or decrease in chemical dosing flow rate into changes in pump speed, thereby achieving fine adjustment of chemical flow rate and avoiding overshoot caused by step-like dosing. Digital logic is more suitable for sludge discharge control. The key points of the sludge discharge valve's operation are whether it is opened, to what degree it is opened, and for how long it is held. Sludge discharge from sedimentation tanks has obvious intermittent and event-triggered characteristics: after the sludge layer accumulates to a certain extent, it needs to be released. If the release is insufficient, the sludge layer will continue to rise. If the release is excessive, the effective water volume will be lost. Therefore, the signal conversion unit converts the sludge discharge opening or closing command into a digital output and combines it with preset logic to control the valve's operation duration and opening degree, so that the sludge discharge operation matches the state of sludge accumulation at the bottom. In terms of system integration, analog outputs are more suitable for connecting continuous execution components such as variable frequency metering pumps and speed control drives; digital outputs are more suitable for connecting solenoid valves, pneumatic valve actuators and their interlocking circuits. Through this one-to-one correspondence, the mapping relationship between control logic and field execution hardware is clear, which facilitates the implementation of programmable logic controllers or distributed control systems, and also makes it easier for maintenance personnel to troubleshoot. As an anomaly protection mechanism, if the analog output has reached its limit but the effluent still deteriorates, the system can issue an alarm for insufficient dosing capacity, prompting the system to check the tank level, pump blockage, or chemical failure; if the sludge discharge valve does not respond properly after receiving the opening command, it can trigger a valve position anomaly alarm and prohibit repeated high-frequency switching to prevent actuator damage; if a communication or output module failure causes the execution command to fail to be implemented, the system can maintain the equipment in the most recent safe state and notify manual takeover. Specifically, during a nighttime high turbidity fluctuation in the Burtai mining area, the system determined that the flocculant ratio needed to be increased and the basic dosage appropriately increased. The signal conversion unit then output the corresponding analog quantity to the polyacrylamide metering pump frequency converter, so that the pump speed was smoothly increased. At the same time, when the turbidity of the bottom sludge layer rose above the sludge discharge criterion, the system issued a digital opening command to control the pneumatic sludge discharge valve to discharge sludge at a predetermined opening for a short time, and then automatically closed after discharging the high-concentration sludge. Throughout the entire process, the dosing and sludge discharge were executed in the most suitable signal form, without mutual interference. The purpose of this mechanism is to reliably convert the results of upper-level linkage control into physical actions that can be executed by field equipment, thereby achieving a reliable connection between the control algorithm and the industrial actuator.

[0026] Furthermore, the data acquisition module collects the influent flow rate and turbidity through an electromagnetic flow meter and an online turbidity meter installed in the influent pipe of the circulating water treatment unit; it collects the vertical depth turbidity through an array of submerged turbidity sensors deployed on the inner wall of the sedimentation unit; and it reads the influent pressure data from the programmable logic controller of the downstream depth filtration unit through a communication protocol.

[0027] This embodiment provides a field measurement point and communication deployment mechanism. Specifically, the aforementioned linkage control relies on the synchronization of multi-source data. If the measurement point layout is unreasonable or the data link is unstable, even if the control logic is complete, it is difficult to form reliable operation. Therefore, this embodiment provides suitable hardware acquisition methods for the water inlet, the stratification end in the pool and the downstream filtration end. Specifically, the inlet pipe uses an electromagnetic flowmeter to acquire flow data, which is suitable for conductive media such as mine water and has good continuous measurement capability for inlet water containing suspended particles; the online turbidity meter is installed in the inlet pipe or bypass sampling loop to reflect changes in the particle load of the inlet water; the combination of the two can simultaneously identify the instantaneous flow rate and the turbidity of the suspended solids in the inlet water, meeting the requirements for the formation of basic dosing dosage. The inner wall of the sedimentation unit is equipped with an array of submerged turbidity sensors. The focus of their arrangement is not to pursue the more sensors the better, but to cover representative water layer locations; for example, the upper layer is used to observe the formation of the clarification zone, the middle layer is used to observe the floc settling transition zone, and the bottom layer is used to observe the accumulation of sludge and the tendency of backmixing. The reason for using an array-style deployment is that sedimentation is not a uniform static process, but rather evolves layer by layer along the vertical direction. A single measuring point cannot effectively reflect the sedimentation structure. Fixing the sensor to the pool wall can reduce measurement instability caused by swaying with the flow, and also facilitates maintenance and regular cleaning. The inlet pressure data of the downstream deep filtration unit is read from its programmable logic controller via a communication protocol, instead of adding a separate pressure acquisition link. This approach is beneficial for achieving cross-section linkage based on the existing plant automation, reducing on-site hardware changes and engineering implementation difficulties. The data read can be existing process variables such as membrane pre-pressure or filter inlet pressure. After accessing the system via communication, the pretreatment control system can incorporate the downstream operating status into local decision-making, eliminating data fragmentation between sections. To address potential anomalies in on-site equipment and communication, and considering that submerged turbidity sensors may experience sludge buildup, scaling, or bubble interference during long-term operation, it is advisable to implement automatic cleaning or periodic maintenance strategies. If the communication protocol is interrupted and downstream pressure data becomes temporarily unavailable, the system can revert to local control based solely on data from this section. If the online turbidity meter for influent is shut down for maintenance, it can temporarily maintain operation based on influent flow rate and gradient within the tank, and the missing measurement status should be marked to avoid mistakenly using estimated values ​​as true values ​​in critical judgments. Specifically, at the Burtai mining area renovation site, electromagnetic flow meters and online turbidity meters are installed on the main inlet pipe. Submerged turbidity probes are installed on the sedimentation tank walls near the mud-water interface in the upper, middle and bottom layers, respectively. The downstream membrane concentration workshop programmable logic controller provides membrane inlet pressure signals to the pretreatment programmable logic controller through a communication network. During night shift operation, the influent turbidity meter first detects the deterioration of the incoming water, the middle and bottom probes reflect changes in the settling zone, and the pressure data in front of the membrane further reflects the degree of impact on the downstream. The three types of data are aggregated within the same control cycle, enabling the system to make coordinated decisions. The purpose of this mechanism is to establish a complete, continuous, and engineerable data acquisition link to ensure that the linkage control has a reliable information foundation.

[0028] Furthermore, the system is applied to mine water treatment scenarios; the circulating water in the circulating water treatment unit includes mixed mine water from the goaf; the downstream deep filtration unit includes a membrane concentration system; and the reagent ratio coefficient is used to adjust the dosage of polyacrylamide.

[0029] This embodiment provides a specific application mechanism for mine water treatment scenarios. Specifically, the entire system is preferably applied to the mixed mine water treatment scenario in the goaf of the Burtai mining area. This type of water body has large fluctuations in suspended solids concentration, and the proportion of fine coal slime, inorganic particle composition, and water inflow rhythm are significantly affected by underground production disturbances. Therefore, it is particularly suitable to adopt the aforementioned linkage control method. Specifically, mixed mine water in goaf areas typically exhibits both high volatility and strong time-varying characteristics; during some periods, it is dominated by coarse-grained coal slime and rock powder, which easily form flocs and settle rapidly; during other periods, the proportion of fine particles increases, making it easier to penetrate pretreatment and contaminate downstream deep filtration units, including membrane thickening systems. Traditional practices often use whether the pretreated effluent meets a certain suspended solids standard as the process endpoint. However, in actual production, downstream deep filtration units, including membrane concentration systems, are more sensitive to fine particles and colloidal impurities. Therefore, if the upstream control does not take the downstream load into account, it can easily lead to an increase in the frequency of chemical cleaning and a decrease in membrane life. In this application scenario, the reagent ratio coefficient is preferably used to adjust the dosage of polyacrylamide; the reason is that polyacrylamide acts more directly on floc bridging and particle aggregation, and is more sensitive to the improvement of the vertical turbidity sedimentation gradient. By dynamically adjusting the dosage of polyacrylamide based on the stratification state in the pool and the influent pressure data of the downstream membrane concentration system, the sedimentation effect can be guaranteed while avoiding problems such as increased viscous sludge and aggravated membrane fouling caused by excessive dosage. Of course, in specific projects, this ratio coefficient can also be synergistically controlled with other coagulants, but the core is still to improve the overall separation effect through fine adjustment of the flocculation process. As a mechanism to cope with extreme working conditions, when the composition of the mixed mine water in the goaf is abnormally complex and the proportion of ultrafine colloids is too high, the adjustment of polyacrylamide alone may not be enough to restore the ideal sedimentation. In this case, the aforementioned downgrade protection can be combined to switch to a conservative mode and the reagent system can be manually readjusted. If the downstream deep filtration unit, which includes a membrane concentration system, is in a shutdown, cleaning or low-load state, the sensitivity of cross-section adaptive control can be appropriately reduced to avoid making excessive control requirements on the upstream under abnormal downstream working conditions. Specifically, during the 30-day comparative operation of the first phase of the Burtai mining area treatment line, under the original flow rate ratio dosing + manual timed sludge discharge mode, although the pretreatment could meet the basic effluent requirements for most periods, the daily average influent pressure data of the membrane concentration system rose rapidly, and the dosing status of the reagents was not optimal. After switching to this system, the system dynamically corrects the dosage of polyacrylamide based on the influent turbidity, stratification state in the pool, and changes in influent pressure data of the mixed mine water in the goaf. When necessary, it also adjusts the sludge discharge rhythm and target effluent turbidity simultaneously. The operating results show that the dosage is accurately controlled by feedback, the clogging rate represented by the influent pressure data is reduced, and the stability of the effluent is improved. The purpose of this mechanism is to implement the aforementioned linkage control scheme in the real industrial scenario of mine water, which is highly volatile and strongly coupled, so as to achieve synergistic optimization between the pretreatment section and the membrane concentration section. It should be noted that the effectiveness of the linkage control strategy based on the vertical turbidity sedimentation gradient depends on the sedimentation differences of suspended solids that can form stratification. When the mining area enters a specific coal seam mining stage, a large amount of ultrafine colloidal coal slurry is mixed into the mine water, and the turbidity of each water layer may be similar for a long time, and the representativeness of the sedimentation gradient parameter will decrease. In this case, the system should trigger the degradation protection, degrade to a fixed proportion of dosing and output a manual intervention alarm to avoid the risk of sludge loss and ensure the safe operation of the downstream deep filtration unit, including the membrane thickening system.

[0030] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A circulating water treatment and purification system based on turbidity monitoring linkage, comprising a dosing actuator and a sludge discharge actuator, wherein the dosing actuator includes a variable frequency metering pump and a dosing pipeline, the variable frequency metering pump being connected to a circulating water treatment unit via the dosing pipeline; the sludge discharge actuator includes a sludge discharge pipeline disposed at the bottom of a sedimentation unit and a pneumatic sludge discharge valve installed on the sludge discharge pipeline, characterized in that, Also includes: The data acquisition module is used to collect influent flow rate and influent turbidity, collect vertical depth turbidity at at least two preset water depths within the sedimentation unit, and collect influent pressure data of the downstream depth filtration unit. Influent flow rate and influent turbidity reflect the total load of suspended solids entering the system per unit time and are the direct basis for basic dosing. The data acquisition module collects influent flow rate and influent turbidity through an electromagnetic flow meter and an online turbidity meter installed in the influent pipe of the circulating water treatment unit. The parameter calculation module is used to obtain the preset initial reagent ratio coefficient and target effluent turbidity setpoint; calculate the basic dosage by multiplying the influent flow rate and influent turbidity with the preset unit turbidity dosage; calculate the vertical turbidity sedimentation gradient based on vertical depth turbidity; and calculate the cross-section load transfer index based on influent pressure data. The preset dosage per unit turbidity is characterized as the mass of standard reagent required to treat a unit volume and a unit turbidity of water. The linkage control module is configured as follows: if the sedimentation gradient is less than the preset sedimentation threshold, the reagent ratio coefficient is increased to generate a dosing control command, which is combined with the basic dosing amount to control the dosing actuator. Otherwise, maintain the current ratio. If the vertical depth turbidity of the bottom water is greater than the preset sludge concentration threshold, the sludge discharge actuator will be activated to discharge sludge; otherwise, sludge discharge will be deactivated. The cross-section adaptive module is configured as follows: if the load transfer index is greater than the preset warning value and continues to exceed the preset warning time, the target effluent turbidity setting value is reduced according to the preset attenuation coefficient; otherwise, the setting value is maintained. The closed-loop feedback module is used to dynamically correct the preset sedimentation threshold based on the deviation between the effluent turbidity and the set value; specifically, the closed-loop feedback module is used for: The difference between the effluent turbidity and the target effluent turbidity setting value is calculated as the turbidity deviation value; Input the turbidity deviation value into a preset proportional-integral-derivative controller; The sum of the proportional, integral, and derivative terms is calculated by outputting the proportional-integral-derivative regulator, and added to the set reference constant to generate a floating correction coefficient. The correction coefficient is then multiplied by the preset settlement threshold to generate an updated preset settlement threshold. The turbidity of the effluent from the sedimentation unit is the final test of the current control results. If the effluent turbidity is higher than the target effluent turbidity for a long period of time, the system will gradually increase its sensitivity to insufficient sedimentation. The parameter calculation module includes: The gradient calculation unit is used to obtain the vertical depth turbidity at the first preset water depth and the vertical depth turbidity at the second preset water depth within the sedimentation unit, calculate the difference between the vertical depth turbidity at the first preset water depth and the vertical depth turbidity at the second preset water depth, and after determining that the absolute value of the height difference between the first preset water depth and the second preset water depth is greater than or equal to a preset effective difference, divide the difference between the vertical depth turbidity at the first preset water depth and the vertical depth turbidity at the second preset water depth by the absolute value of the height difference to generate the vertical turbidity sedimentation gradient. The load calculation unit is used to extract the time partial derivative of the continuous inlet pressure data obtained based on a preset sampling time interval, so as to generate the cross-section load transfer index.

2. The circulating water treatment and purification system based on turbidity monitoring linkage according to claim 1, characterized in that, The parameter calculation module is also used to extract the time partial derivative of the influent turbidity to calculate the influent turbidity change rate. The linkage control module is further configured to: if the rate of change of influent turbidity is greater than a preset abrupt change threshold, generate a feedforward dosing compensation instruction and superimpose it on the dosing control instruction; otherwise, do not generate the feedforward dosing compensation instruction.

3. The circulating water treatment and purification system based on turbidity monitoring linkage according to claim 1, characterized in that, The system also includes a degradation protection module, configured as follows: If the vertical turbidity sedimentation gradient is less than the preset failure threshold and the duration exceeds the preset failure duration, the suspended solids sedimentation characteristics are determined to be faulty, triggering a degradation protection mechanism. The dosing control command is switched to a preset fixed ratio dosing mode, and a manual intervention alarm signal is output. Otherwise, the current control logic of the linkage control module is maintained.

4. The circulating water treatment and purification system based on turbidity monitoring linkage according to claim 1, characterized in that, The linkage control module also includes a signal conversion unit for: The dosing control command is converted into an analog signal to control the motor speed of the dosing actuator; The sludge discharge start command or sludge discharge stop command is converted into a digital signal to control the valve opening degree and opening duration of the sludge discharge actuator.

5. A circulating water treatment and purification system based on turbidity monitoring linkage according to claim 1, characterized in that, The vertical depth turbidity is collected by an array of submerged turbidity sensors deployed on the inner wall of the sedimentation unit; the inlet pressure data is read from the programmable logic controller of the downstream depth filtration unit via a communication protocol.

6. A circulating water treatment and purification system based on turbidity monitoring linkage according to any one of claims 1 to 5, characterized in that, The system is applied to mine water treatment scenarios; the circulating water in the circulating water treatment unit contains mixed mine water from the goaf; the downstream deep filtration unit includes a membrane concentration system; and the reagent ratio coefficient is used to adjust the dosage of polyacrylamide.

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