Fine quality-divided recycling system and method for tail water in tap water production

Abstract

The invention discloses a fine quality-divided recycling system and method for tail water in tap water production, and the system comprises a front-end tail water monitoring subsystem which is used for carrying out the online monitoring of water quality indexes of the tail water of a sedimentation tank, the tail water of a sand filter, the tail water of an activated carbon filter and the tail water of a filter membrane through a sensor; and the tail water quality calculation subsystem is connected with the front-end tail water monitoring subsystem and is configured to perform water quality prediction and segmented calculation on the monitoring data based on a machine learning algorithm and output optimal reuse parameters. According to the method, fine quality-divided collection, mixing and recycling of the tail water are carried out by utilizing the instantaneous calling optimal maximum grid number in real time, the recyclable maximum flow is obtained under the condition that the water quality guarantee rate of the water production line is 90%, the tail water saving efficiency can be improved by 94% or above, the recycling water saving amount can be optimally achieved by 10.2 times or above under the same tail water quality background, and the method is suitable for industrial production. Potential risks are reduced through a self-adaptive method, and meanwhile the purposes of saving water resources and guaranteeing that the water quality reaches the standard are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of fine quality separation of tap water production tail water, and particularly relates to a fine quality separation and reuse system and method for tap water production tail water. Background Art

[0002] The conservation and recycling of water have become one of the hot topics continuously concerned in the fields of water resources and water security. There is recyclable water resource in the process of drinking water treatment, but it has not attracted enough attention and there is also a lack of corresponding reuse technical means.

[0003] Specifically, during the production process of a waterworks, sludge water is generated in the sedimentation tank, and the sand filter and activated carbon filter need to be periodically backwashed, generating backwash water. Waterworks adopting membrane treatment process also have membrane cleaning wastewater. These are all the production tail water of the waterworks. Its water volume usually accounts for 2%-8% of the total water production of the waterworks. If reasonably reused, a huge amount of water resources will be saved. Taking a waterworks with a production scale of 500,000 m 3 / d as an example, assuming that the proportion of production tail water is 3%, if all of it is reused, 15,000 m 3 of water can be saved every day. The effective reuse of the above-mentioned tail water can meet the basic water use needs of 140,000 people every day.

[0004] However, there will be risks if these production tail waters are directly reused, and the risk characteristics of the tail water quality between different process units or different process stages of the same process unit are also different. The main components of the sedimentation tank tail water are the floc particles formed in the coagulation process, which include suspended particles, colloids, algae, microorganisms and some organic matters, etc., and its water quality is usually poor. During the operation of the sand filter and activated carbon filter, as the filter media become blocked, periodic backwashing needs to be carried out using the clear water before disinfection treated by the waterworks. The backwash water of the sand filter mainly includes small particle flocs, microorganisms and some organic matters that were not removed during the sedimentation process; the backwash water of the activated carbon filter mainly has a certain microbial risk, which mainly comes from the shedding of the biofilm on the surface of the activated carbon particles. Compared with the sludge water, the water quality of the backwash water of the two filters is relatively better, and the possibility of its direct reuse is correspondingly greater. In addition, due to the obvious water quality change during the backwashing process itself, the water quality of the end-stage backwash water is significantly better than that of the initial-stage backwash water. Therefore, by carrying out staged and quality-separated collection and reuse of the tail water, it will be a potential direction for the refined reuse of the production tail water of the waterworks. At the same time, affected by factors such as water source water quality in different regions, different waterworks processes and operating parameters, etc., the water quality of the production tail water of each process unit varies greatly in actual projects. For the tail water with these differences, there is also a lack of criteria for judging whether the production tail water can be reused, the reuse method, and the risk assessment and control standards after reuse.

[0005] Generally speaking, the main difficulties in the reuse of the tail water from water treatment plants come from the differences in the risk characteristics of the tail water quality between different process units or different process stages of the same process unit, as well as the lack of risk assessment and control standards caused by factors such as the water quality of water sources in different regions, the processes of different water treatment plants, and operating parameters. However, there is currently no technology that can achieve the fine-quality and efficient reuse of the tail water produced by water treatment plants.

[0006] As described above, for this reason, we have designed a fine-quality and fractionated reuse system and method for the tail water of tap water production to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to solve the deficiencies existing in the prior art, and a fine-quality and fractionated reuse system and method for the tail water of tap water production are proposed.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A fine-quality and fractionated reuse system for the tail water of tap water production, comprising:

[0010] A front-end tail water monitoring subsystem, configured to perform on-line monitoring of water quality indicators for the tail water of sedimentation tanks, sand filtration tanks, activated carbon filtration tanks, and membrane filtration tanks through sensors;

[0011] A tail water fractionation calculation subsystem, connected to the front-end tail water monitoring subsystem, configured to perform water quality prediction and segmented calculation on the monitoring data based on machine learning algorithms, and output optimal reuse parameters;

[0012] A pump-valve intelligent control subsystem, connected to the fractionation calculation subsystem, configured to execute fractionation adjustment instructions;

[0013] A tail water fractionation adjustment and transportation subsystem, including a grid adjustment tank and transportation equipment, controlled by the pump-valve intelligent control subsystem to achieve the fractionated storage and directional reuse of tail water.

[0014] Preferably, the water quality indicators monitored by the front-end tail water monitoring subsystem are selected from S items among the 97 items specified in GB 5749-2022 "Hygienic Standards for Drinking Water", where S≥1, and at least include one of turbidity, permanganate index, total colony count, and aluminum.

[0015] Preferably, the tail water fractionation calculation subsystem includes:

[0016] An adaptive boundary calculation module, configured to determine the boundary values of each water quality indicator based on the Pearson type III skewed distribution fitting of historical influent water quality data;

[0017] A fine-quality fractionation combination calculation module, configured to generate a tail water fractionation strategy by combining pre-compilation and real-time operation.

[0018] Preferably, the method for selecting the boundary value of the adaptive boundary calculation module is as follows:

[0019] When using the pre-compilation method, select the quantile of 90% and above of the historical water quality data distribution as the boundary value;

[0020] When using the real-time training method, calculate the dynamic boundary value through the raw water quality monitoring data of 1 - 12 months.

[0021] Preferably, when the fine fractionated combination calculation module runs:

[0022] Establish a policy set A = {a 1 , a 2 ,..., a_p}, where a is a separable mass combination scheme, each scheme contains parameter combinations such as time parameters, flow parameters, and reuse ratios, and p is the total number of separable mass combination schemes;

[0023] Taking the maximization of the water saving amount by reuse as the objective function, solve the optimal combination scheme through the objective convergence method and the exhaustive method.

[0024] Preferably, the grid adjustment tank satisfies:

[0025] The total volume is 85% - 100% of the single-day tail water discharge amount;

[0026] The number of grids is 3 - 10 times the number of tail water discharge structures;

[0027] It is configured to achieve fine fractionated storage of 1 / 3 - 1 / 10 flow segments according to the division of discharge time and space.

[0028] Preferably, the out-of-tank control of the grid adjustment tank satisfies:

[0029] The out-of-tank flow rate , where k is the spatial division of the structure, j is the division of discharge time, and T is the out-of-tank duration;

[0030] The water quality concentration after reuse: , where , are the original flow rate and concentration of the water production line respectively.

[0031] Preferably, the pump-valve intelligent control subsystem is configured to:

[0032] Dynamically control the opening and closing combination of the lift pump and the valve;

[0033] Implement tail water isolation or homogeneous mixing operations according to the results of fractionated calculation.

[0034] A method for fine fractionated reuse of tap water production tail water includes the steps:

[0035] Step S1: Collect multi-dimensional water quality data of the tail water in each process section in real time;

[0036] Step S2: Predict the water quality change trend through a machine learning model and divide the water quality sections;

[0037] Step S3: Calculate the optimal reuse parameter combination;

[0038] Step S4: Control the grid adjustment tank to store and discharge the tail water according to the water quality separation strategy;

[0039] Step S5: Reuse the separated tail water to the water production line according to the calculated ratio.

[0040] Preferably, the determination of the reuse parameter combination includes:

[0041] Calculate the boundary values of water quality indicators based on the Pearson type III distribution;

[0042] Select the water quality separation combination scheme that maximizes the objective function V_max in the strategy set A through the target convergence method and the exhaustive method.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows: Due to the innovative proposal of the efficient reuse concept of "fine water quality separation" and the specific technical method, the present invention can effectively utilize the newly added reasonable structures and equipment to achieve the refined water quality separation and collection of the tail water of different tail water discharge process units, including sedimentation tanks, sand filters, activated carbon filters, and filter membranes, as well as the tail water at different discharge stages of the same tail water discharge process unit. Even under the most extreme adverse working conditions, the tail water can still be stored in a refined water quality flow section of every 1 / 3 - 1 / 10 to achieve the maximum reuse water volume. At the same time, the present invention compiles the optimization program of the fine water quality separation combination calculation module, and uses the optimal maximum number of grids that can be called instantaneously in real time to collect or mix the tail water with fine water quality separation, so as to obtain the maximum reusable flow rate under the water quality guarantee rate of the vast majority of water production lines, which can improve the tail water saving efficiency by more than 94%. Under the same tail water quality background, the optimal water saving volume for reuse can reach more than 10.2 times. The potential risks are reduced through the adaptive method, and at the same time, the purpose of saving water resources and ensuring the water quality compliance is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the fine water quality separation and efficient reuse system for the production tail water of the waterworks of the present invention.

[0045] Figure 2 It is a schematic diagram of the method for efficient reuse of refined water quality separation of the production tail water of the waterworks of the present invention.

[0046] Figure 3The figure shows the adaptive boundary calculation results of the adaptive boundary calculation module of the fine-quality and highly efficient reuse system for the tail water produced by the waterworks in the present invention for the actual background of a certain waterworks.

[0047] Figure 4 The figure shows the calculation process diagram of the fine-quality combination calculation module of the fine-quality and highly efficient reuse system for the tail water produced by the waterworks in the present invention for the actual tail water of a certain waterworks.

[0048] Figure 5 The figure shows the comparison of the reusable water volume results of the present invention and the comparative example without using the present invention for the actual tail water of a certain waterworks during reuse.

[0049] Figure 6 The figure shows the comparison of the reuse rate results of the present invention and the comparative example without using the present invention for the actual tail water of a certain waterworks during reuse. Specific embodiments

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0051] Refer to Figures 1 - 6 , a fine-quality reuse system and method for the tail water produced by tap water production, including subsystems such as front-end tail water monitoring, tail water quality calculation, intelligent control of pumps and valves, tail water quality adjustment, and conveying system; the front-end monitoring system monitors the water quality of the tail water of the waterworks, such as the tail water of the sedimentation tank, sand filter tank, activated carbon filter tank, and membrane filter, through sensors, and transmits the key controlled water quality index data to the tail water quality calculation system; the tail water quality calculation system uses the tail water monitoring data for machine learning and tail water quality prediction, performs refined segmentation on the water quality of different process tail waters, solves the optimal extreme value according to the intelligent algorithm, and transmits the optimal reuse parameters to the intelligent control system of pumps and valves; after the intelligent control system of pumps and valves finely manipulates the tail water quality adjustment and conveying system, the fine-quality and highly efficient reuse of the production tail water can be realized.

[0052] Specifically, the front-end monitoring system online monitors the water quality indexes of the tail water from the process structures that produce tail water, such as sedimentation tanks, sand filter tanks, activated carbon filter tanks, and membranes. The specific structures to be accessed can be selected according to the actual process and engineering planning of the waterworks, and can be selected according to the actual sensitive indexes of the waterworks. Its horizontal random variable is (L = 1, 2, 3,..., S, where S is the total number of selected water quality indexes). The specific water quality indexes are selected from the 97 water quality indexes specified in the "Hygienic Standards for Drinking Water" (GB 5749). The online monitoring index range preferably includes key water quality indexes such as turbidity, permanganate index, total coliforms, and aluminum.

[0053] Among them, the internal calculation module of the tail water quality separation calculation system consists of an adaptive boundary calculation module and a fine quality separation combination calculation module.

[0054] More specifically, if the writing of the adaptive boundary calculation module inside the tail water quality separation calculation system adopts the pre-compilation method, historical data of the raw water inlet water quality needs to be input, and the probability distribution of the raw water quality parameters is statistically analyzed and fitted, preferably with a Pearson type III skewed distribution; the selection range of water quality indicators includes key water quality indicators such as turbidity, permanganate index, total colony count, and aluminum. Other specific water quality indicators that can be selected are selected from the 97 water quality indicators specified in the "Sanitary Standards for Drinking Water" (GB 5749), and can be selected according to the actual sensitive indicators of the water supply plant and kept consistent with other component systems; according to the fitting result of the inlet water quality indicators, the quantile above 90% (including) is selected as the limit of the Lth single water quality indicator among the selected water quality indicators (L = 1, 2, 3, …, S, where S is the total number of selected water quality indicators), preferably the 90% quantile, that is If the writing of the adaptive boundary calculation module does not adopt the pre-compilation method, the above steps are realized through real-time monitoring records of the raw water quality, and a training period of 1 to 12 months is carried out, preferably 12 months as the training period.

[0055] Among them, the writing of the fine quality separation combination calculation module inside the tail water quality separation calculation system runs in the way of pre-compilation + online real-time operation.

[0056] More specifically, the tail water quality separation regulation and conveying system consists of structures and equipment with quality separation regulation functions and conveying functions; the structure with quality separation regulation function is the grid regulation tank, and the total volume of the grid regulation tank is 85% to 100% of the daily total tail water drainage (mud) volume, preferably 85% of the regulation volume to save land; the structures and equipment with conveying functions consist of several lift pumps, valves (gates), pipes (channels), and the designed size and discharge capacity of the pipes (channels) meet the requirement of conveying the tail water with a flow rate of within the tail water discharge time of (k = 1, 2, 3, …, m, which is the spatial division of the structure where the tail water is discharged; j = 1, 2, 3, …, n, which is the discharge time division of the discharged tail water), and its designed size and discharge capacity can meet the instantaneous transient cumulative flow rate when multiple structures discharge tail water simultaneously ; the connection method between the tail water quality separation regulation and conveying system and the structures of the water production line is: structures of the water production line (tail water pipeline) → conveying system → quality separation regulation system → conveying system → structures of the water production line (reclaimed water pipeline).

[0057] Among them, the divided regulating tank with the function of separate quality regulation has the number of grids being 3 to 10 times the sum of the tail water discharge structures. Under the extreme condition of discharging tail water from all structures, it can still complete the demarcation of the tail water of each stage of each process unit according to the start, initial stage, until the end stage, and end of the discharge time, store the separated quality of each 1 / 3 to 1 / 10 fine separated quality flow section of the tail water, and can use the idle tank grids to achieve more refined separated quality storage under normal conditions. Therefore, the flow rate of the tail water to be recycled out of the regulating tank (k = 1, 2, 3, …, m, which is the spatial division of the structures discharging the tail water; j = 1, 2, 3, …, n, which is the discharge time division of the discharged tail water; T is the length of the time for continuous discharge out of the tank), the outlet concentration of the Lth water quality index when discharging evenly out of the tank (k = 1, 2, 3, …, m, which is the spatial division of the structures discharging the tail water; j = 1, 2, 3, …, n, which is the discharge time division of the discharged tail water; L = 1, 2, 3, …, S, where S is the total number of selected water quality indicators; is the concentration value of the Lth water quality index in the kth spatial division and the jth time division). Therefore, when the tail water is recycled out of the tank and returned to the water production line, the concentration after recycling of the Lth water quality index ( , are the original flow rate of the water production line and the concentration value of the Lth water quality index respectively).

[0058] More specifically, the pump-valve intelligent control system controls the opening and closing states, opening durations, and opening and closing combinations of the structures and equipment (lifting pumps, valves (gate valves)) with conveying functions in the tail water separate quality regulation and conveying system, realizes the fine separate quality collection of the tail water, and realizes the necessary tail water isolation or homogeneous mixing according to the feedback of the calculated data.

[0059] Furthermore, the present invention provides a fine separate quality and high-efficiency reuse method for the fine separate quality reuse system of the tap water production tail water. The program pre-compiled by the fine separate quality combination calculation module performs online calculation on the real-time value, determines and controls the tail water combination method in real time to ensure , and is composed of the reuse ratio n% and the corresponding total discharge volume ; uses the optimal maximum number of grids that can be called instantaneously in real time for fine separate quality collection or mixing of the tail water. For the combination discharge schemes that can meet , the combination schemes of all tank grids are optimized by the target convergence method and the exhaustive method, that is, there is a strategy set A = {a 1 , a 2 ,..., a_ p}, where a is a separable quality combination scheme, each scheme contains parameter combinations such as time parameter, flow parameter, reuse ratio, etc., p is the total number of separable quality combination schemes, and the fine separable quality combination calculation module calculates the optimal solution as the objective function to obtain the maximum water saving by reuse.

[0060] Example 1

[0061] This example discloses a fine separable quality high - efficiency reuse method in a method and system for fine separable quality reuse of tap water production tail water. A water supply plant in East China is selected as the implementation object. Its sand filter and activated carbon filter both produce production tail water during operation, and the pump - valve intelligent control system and tail water separable quality regulation and transportation system carry out fine separable quality high - efficiency reuse on it. The specific implementation method is as Figure 1 and Figure 2 shown. Among them, for the physical space of the sand filter and activated carbon filter of the water supply plant, it is divided into m = 2 tail water discharge spaces, that is, k = 1 and k = 2; for the tail water discharge flow of each pool body, it is evenly divided into n = 3 tail water discharge time stages, that is, j = 1, j = 2, and j = 3. At this time, the total tail water discharge is: (1)

[0062] Among them, and are the tail water discharge flow and tail water discharge time under the k - th space division and the j - th time division respectively.

[0063] So far, the present invention has completed the example of fine separable quality of production tail water.

[0064] Example 2

[0065] This example discloses an adaptive boundary calculation example in a method and system for fine separable quality reuse of tap water production tail water. A water supply plant in East China is selected as the implementation object. The total number of colonies in the raw water quality index is selected as a monitoring index, and its adaptive boundary calculation is carried out. The specific calculation results are as Figure 3 shown. For a set of measured value random variables X = (1000, 88, 1500, 74, 620, 640, 76000, 2400) of the selected index of the raw water quality T Pearson type III fitting is selected, and the calculated index level at a 90% quantile guarantee rate is 1263 CFU / mL. Then, the water quality index boundary after adapting to the raw water quality is:

[0066] (2)

[0067] So far, the present invention has completed the example of adaptive boundary calculation of production tail water.

[0068] Example 3

[0069] This example discloses a fine-quality combined calculation example in a method and system for the fine-quality reuse of tap water production tail water. A water supply plant in East China is selected as the implementation object. The calculation results are as shown in Figure 4 , Figure 5 , Figure 6 . The single-round tail water discharge of its sand filter is 3060 m 3 , and the single-round tail water discharge of the activated carbon filter is 1257 m 3 . Then, the discharge flow rate adjusted within a cycle with a discharge duration of T is: (3)

[0070] For the total number of colonies in the selected water quality indicators, considering the reuse ratio under the constraint of this single factor Then there is a corresponding reuse flow rate: (4)

[0071] Correspondingly, for the discharged tail water and the reused tail water, there are their water quality indicator levels: (5)

[0072] In this example, the case of reusing the tail water to the raw water end of the water supply plant is considered. After the tail water is connected to the raw water through the tail water quality regulation and transportation system, the water quality indicators after complete mixing are: (6)

[0073] Among them, , are the original flow rate of the water production line and the concentration value of the Lth water quality indicator respectively;

[0074] Taking the mixing link as the constraint step for water quality risk control, and predicting and controlling the water quality indicator level after mixing in real time to strictly meet the established adaptive boundary, that is: (7)

[0075] For all feasible solutions that meet the single-factor constraints, a feasible region in this example is formed: (8)

[0076] According to the specific fine-quality reuse method of this example, it is easy to obtain the total number of reuse scheme solutions formed in this example by the enumeration method as: (9)

[0077] The results of its iterative calculation are as shown in Figure 4As shown in the figure. First, the solution set that meets the boundary condition (7) is screened to form the feasible region (8), and then, according to the principle of optimal solution selection, the fine-quality combination calculation module calculates the optimal solution with as the objective function to obtain the maximum water saving by reuse, as Figure 5 , Figure 6 shown. At this time, there is a fine-quality reuse scheme: (10 - 1) (10 - 2)

[0078] The composition of the optimal solution indicates the tail water in two stages when k = 1 and j = 1 and j = 2, that is, the initial first-stage and second-stage tail water of the sand filter. Since the pollutants filtered out are highly concentrated in it, it is advisable to discard it without reuse. At this time, collecting the tail water in these two stages will instead reduce the final reusable water volume; at the same time, there are the maximum reuse rate and the final reusable water volume: (11) (12)

[0079] So far, the present invention has completed an example of fine-quality combination calculation, optimal reuse scheme calculation, and optimal solution solving calculation.

[0080] Comparative Example 1

[0081] Taking the non-fine-quality reuse method that does not use the present invention as a comparative example, the results are as Figure 5 , Figure 6 shown. Select a water treatment plant in East China as the comparison background, keep the tail water discharge conditions of the tested sand filter and activated carbon filter the same as those in the example, inject all the complete tail water of the sand filter and activated carbon filter into the same regulating structure, the single-round tail water discharge volume of the sand filter is 3060 m 3 , and the single-round tail water discharge volume of the activated carbon filter is 1257 m 3 . Based on the principle of water quality safety guarantee, set the same boundary conditions as (7), and at this time, there are: (13 - 1) (13 - 2) (14) (15)

[0082] is the flow rate of the tail water to be reused and discharged from the regulating pool in the example;

[0083] is the flow rate of the tail water to be reused and discharged from the regulating pool in the comparative example;

[0084] is the reuse ratio under the single-factor constraint for the L-th water quality index;

[0085] is the reuse flow rate under the single-factor constraint for the L-th water quality index.

[0086] This indicates that without using the present invention, due to the relatively large pollution of the initial tail water in the sand filter, the total amount of untreated tail water without fine quality separation is significantly polluted by the initial tail water, resulting in only 222.7 m 3 available for reuse, and the saved reused tail water only accounts for 5.16% of the total collected tail water. Taking the reuse ratio n L % as the evaluation index, the reuse rate of the present invention after fine quality separation can reach 100% for all reuse, while the comparative example is only 5.16%. The present invention can improve the tail water saving efficiency by more than 94%. Taking the final reused water volume as the evaluation index, the available reused water volume after fine quality separation of the present invention is 2277 m 3 , while the comparative example is only 222.7 m 3 , and the present invention can achieve more than 10.2 times the amount of saved reused water under the same tail water quality background. This indicates that under such conditions, the present invention is superior to the reuse technology of the comparative example without using the present invention.

[0087] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope claimed by the present invention. The scope claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A system for fine separation and reuse of tap water production tail water, characterized in that: include: The front-end tailwater monitoring subsystem is configured to conduct online monitoring of water quality indicators of sedimentation tank tailwater, sand filter tank tailwater, activated carbon filter tank tailwater and membrane filter tailwater through sensors; A tailwater quality calculation subsystem, connected to the front-end tailwater monitoring subsystem, configured to perform water quality prediction and segmented calculation on the monitoring data based on a machine learning algorithm, and output optimal reuse parameters; A pump and valve intelligent control subsystem, connected to the quality-based calculation subsystem, configured to execute quality-based adjustment instructions; The tail water quality control and transportation subsystem includes a grid regulating tank and transportation equipment, which is controlled by the pump and valve intelligent control subsystem to achieve quality-based storage and directional reuse of tail water.

2. A tap water production tail water fine separation and reuse system according to claim 1, characterized in that: The water quality indicators monitored by the front-end tailwater monitoring subsystem are selected from S items of the 97 indicators specified in GB 5749-2022 "Sanitary Standards for Drinking Water", where S≥1, and include at least one of turbidity, permanganate index, total colony count and aluminum.

3. A tap water production tail water fine separation and reuse system according to claim 1, characterized in that: The tail water quality calculation subsystem includes: An adaptive boundary calculation module, configured to determine the boundary values ​​of each water quality index based on the Pearson III skewed distribution fitting of historical influent water quality data; The fine quality combination calculation module is configured to generate tail water quality strategy by combining pre-compilation with real-time calculation.

4. A tap water production tail water fine separation and reuse system according to claim 3, characterized in that: The method for selecting the limit value of the adaptive boundary calculation module is: When the pre-compilation method is used, the 90th percentile and above of the historical water quality data distribution is selected as the boundary value; When the real-time training method is adopted, the dynamic limit value calculation is performed through 1-12 months of raw water quality monitoring data.

5. A tap water production tail water fine separation and reuse system according to claim 3, characterized in that: When the fine quality combination calculation module is running: Establish a strategy set A={a1,a2,...,ap}, where p is the total number of separable quality combination schemes; Taking maximizing the amount of water saved by reuse as the objective function, the optimal combination solution is solved through the target convergence method and the exhaustive method.

6. A tap water production tail water fine separation and reuse system according to claim 1, characterized in that: The grid regulating pool meets the following requirements: The total volume is 85%-100% of the daily tailwater discharge; The number of compartments is 3-10 times the number of tailwater discharge structures; It is configured to achieve fine quality-differentiated storage of 1 / 3-1 / 10 flow segments according to discharge time and space.

7. A tap water production tail water fine separation and reuse system according to claim 6, characterized in that: The outbound control of the grid regulating pool meets the following requirements: Outbound flow , where k is the spatial division of the structure, j is the time division of the discharge, and T is the duration of the discharge; Water concentration after reuse: ,in , are the original flow rate and concentration of the water production line respectively.

8. A tap water production tail water fine separation and reuse system according to claim 1, characterized in that: The pump and valve intelligent control subsystem is configured as follows: Dynamically control the opening and closing combination of lift pumps and valves; Tail water isolation or homogenous mixing operations are carried out according to the results of quality separation calculation.

9. A method for fine separation and reuse of tap water production tail water based on any one of claims 1 to 8, characterized in that: Includes steps: Step S1, real-time collection of multi-dimensional water quality data of tail water from each process section; Step S2: predicting the water quality change trend and dividing the water quality into different sections through machine learning model; Step S3, calculating the optimal reuse parameter combination; Step S4, controlling the grid regulating tank to store and discharge tail water according to the quality strategy; Step S5: Reuse the separated tail water to the water production line according to the calculated ratio.

10. The method according to claim 9, characterized in that The determination of the reuse parameter combination includes: Calculate water quality index boundary values ​​based on Pearson III distribution; Through the target convergence method and exhaustive method, the qualitative combination scheme that maximizes the objective function V_max is selected from the strategy set A.

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