A wastewater classification and separation system based on industrial wastewater recycling

Abstract

This invention discloses a wastewater classification and separation system based on industrial wastewater recycling. The invention relates to the field of industrial wastewater treatment and resource recycling technology. The system includes a wastewater acquisition and pretreatment module, a multi-parameter real-time water quality detection module, a comprehensive pollution classification and determination module, a separation and control module, a classification storage and buffer module, a classification treatment module, a recycling intelligent scheduling module, and a data acquisition and intelligent management module. This invention utilizes a collaborative working mechanism of multi-parameter real-time water quality detection and comprehensive pollution classification and determination. It employs a piecewise linear dimensionless scoring function to uniformly map five water quality indicators to a scoring range of 0–10 and then performs a weighted summation. This achieves multi-dimensional, accurate, and real-time determination of the pollution level of industrial wastewater, overcoming the shortcomings of existing technologies where single-indicator judgments are inaccurate and multi-indicator dimension inconsistencies prevent comprehensive evaluation. The targetedness and effectiveness of wastewater classification and treatment are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of industrial wastewater treatment and resource recycling technology, specifically a wastewater classification and separation system based on industrial wastewater recycling. Background Technology

[0002] The treatment and resource utilization of industrial wastewater is an important research direction in the fields of water resource management and environmental protection. In the process of industrial production, the wastewater generated by different production processes varies significantly in terms of pollutant types, concentration distribution, and water quality characteristics. The production wastewater from industries such as manufacturing, chemical industry, metallurgy, and textile industry often contains a variety of pollutants, including organic pollutants, heavy metal ions, suspended solids, and strong acid and alkaline substances. The degree of pollution of wastewater from each process varies significantly. Existing industrial wastewater treatment systems usually adopt a unified collection and mixed treatment model, which indiscriminately merges wastewater from different production processes into the same treatment process for overall disposal. This treatment method has obvious technical defects. Existing technologies treat wastewater sequentially by using a series of processes such as coarse filtration, chemical precipitation, and biochemical treatment. However, this system has the following shortcomings: First, it lacks the ability to determine the comprehensive pollution level of wastewater in real time based on multi-parameter detection. Lightly polluted wastewater is mixed with heavily polluted wastewater in the same treatment unit, causing secondary pollution of lightly polluted water bodies by the heavily polluted wastewater, unnecessarily increasing the difficulty of subsequent treatment and the consumption of chemical reagents. Second, the system lacks the function of physically separating and storing wastewater according to its pollution level. Wastewater from different sources and with different pollution levels is difficult to treat separately with targeted differentiated processes after mixing, resulting in low overall treatment efficiency and serious resource waste. Third, the system lacks the ability to monitor the treated wastewater... The intelligent scheduling function for targeted allocation of reclaimed water based on actual water quality conditions fails to allocate reclaimed water to suitable production processes according to water quality levels, resulting in poor cascade utilization of water resources. Fourth, the system relies on a single water quality indicator for judgment, making it difficult to comprehensively and accurately reflect the overall pollution status of wastewater. Due to the different dimensions and large differences in magnitude of various pollution indicators in industrial wastewater (e.g., pH range of 0-14, while COD can reach thousands of mg / L), existing technologies cannot unify multi-indicator data to the same scoring scale for comprehensive evaluation. The industry generally believes that the implementation of multi-indicator weighted comprehensive scoring is too complex and has abandoned its adoption. This invention overcomes the above-mentioned technical biases by using a piecewise linear dimensionless scoring function to achieve multi-parameter comprehensive classification judgment. Summary of the Invention

[0003] To address the shortcomings of the existing technologies, the technical problem this invention aims to solve is: how to achieve real-time and accurate determination of the comprehensive pollution level of industrial wastewater based on multi-parameter water quality detection, and on the basis of determination, to implement complete physical separation, storage and differentiated treatment of wastewater of different levels, while realizing intelligent scheduling of quality-oriented allocation of treated reclaimed water, thereby improving the accuracy of graded treatment of industrial wastewater, the reliability of separation management and the efficiency of water resource recycling.

[0004] To address the aforementioned technical problems, this invention provides a wastewater classification and separation system based on industrial wastewater recycling. The system includes a wastewater acquisition and pretreatment module, a multi-parameter real-time water quality detection module, a comprehensive pollution classification and determination module, a separation control module, a classification storage and buffer module, a classification treatment module, a recycling intelligent scheduling module, and a data acquisition and intelligent management module.

[0005] The wastewater collection and pretreatment module is responsible for the preliminary collection and summarization of wastewater generated from various processes in industrial production. It removes large suspended solids and floating impurities with a particle size greater than 5mm from the wastewater through a bar screen filter. After the preliminary pretreatment is completed, the wastewater is transported to the multi-parameter water quality real-time monitoring module.

[0006] The multi-parameter real-time water quality monitoring module measures the pH value, chemical oxygen demand (COD), suspended solids (SS), and ammonia nitrogen concentration of wastewater. The system performs real-time online monitoring of five key water quality indicators, including total heavy metal ions, and transmits the monitoring data to the comprehensive pollution classification and judgment module in real time.

[0007] The comprehensive pollution classification and determination module calculates a weighted comprehensive score based on the built-in classification threshold system for multi-parameter detection data, classifying wastewater into three levels: lightly polluted wastewater, moderately polluted wastewater, and heavily polluted wastewater, and sends the classification result instructions to the separation control module in real time.

[0008] Based on the received wastewater grade instructions, the separation control module drives the electric regulating valve and pipeline switching device to precisely guide wastewater of different grades to their corresponding independent storage areas, achieving complete physical separation between the three grades of wastewater and preventing cross-mixing and pollution of wastewater with different pollution levels.

[0009] The graded storage and buffer module includes independent storage tanks corresponding to three pollution levels. Each storage tank is equipped with a liquid level sensor to monitor the storage status in real time and feed the liquid level data back to the data acquisition and intelligent management module, providing data support for the orderly scheduling of the graded processing module.

[0010] The graded treatment module adopts differentiated treatment processes for different levels of wastewater: lightly polluted wastewater is treated by precision filtration and ultraviolet disinfection before entering the lightly polluted reclaimed water storage tank. The moderately polluted wastewater undergoes coagulation sedimentation and aeration biochemical treatment in sequence. After meeting the reclaimed water quality standards, it enters the moderately reclaimed water storage tank. Heavily polluted wastewater undergoes four processes in sequence: chemical precipitation, advanced oxidation, aeration and biochemical treatment, and deep filtration, to ensure that the treated water quality meets the standards for reuse or meets the discharge requirements.

[0011] The intelligent scheduling module for recycling dynamically formulates a recycling water allocation plan based on the actual water quality of each level of recycled water and the real-time water demand of each production process. It prioritizes the allocation of lightly treated recycled water to processes with relatively low water quality requirements, such as cooling circulation and site washing, while allocating deeply treated recycled water to production processes with higher water quality requirements, such as product cleaning and process cooling, thereby realizing the tiered utilization of water resources.

[0012] The data acquisition and intelligent control module summarizes the operational status data of each module in real time, monitors the overall system operation, provides early warning of anomalies and remote management, and supports the storage and statistical analysis of historical data, providing decision support for optimizing system operating parameters.

[0013] Compared with the prior art, the beneficial effects of the present invention by adopting the above technical solution are as follows: (1) This invention uses a collaborative working mechanism of real-time multi-parameter water quality detection and comprehensive pollution classification judgment. It adopts a piecewise linear dimensionless scoring function to uniformly map five water quality indicators to the 0-10 scoring range and perform weighted summation, thereby realizing multi-dimensional accurate and real-time judgment of the pollution level of industrial wastewater. This overcomes the shortcomings of existing technologies, such as inaccurate judgment of single detection indicators and the inconsistency of multiple indicators' dimensions, which leads to the inability to conduct comprehensive evaluation. The pertinence and effectiveness of wastewater classification treatment are significantly improved.

[0014] (2) By closely cooperating with the separation control module and the hierarchical storage module, the present invention achieves complete physical separation and storage of wastewater of different grades, thereby avoiding the problem of secondary pollution of lightly polluted wastewater by heavily polluted wastewater from the source, effectively reducing the overall treatment cost and improving the rational allocation efficiency of treatment resources.

[0015] (3) The present invention implements differentiated treatment processes for wastewater of different grades through a graded treatment module, avoiding unnecessary over-treatment of lightly polluted wastewater, and saving treatment agents and energy consumption while ensuring treatment effect, thus significantly improving overall treatment efficiency.

[0016] (4) The present invention realizes the graded and targeted allocation of treated recycled water by means of a recycling intelligent scheduling module, so that the quality of recycled water is accurately matched with the water demand of each production process, effectively improving the resource recycling rate of industrial wastewater and promoting the recycling and conservation of industrial water. Attached Figure Description

[0017] Figure 1 This is a diagram showing the overall architecture of the wastewater classification and separation system of the present invention. Figure 2 This is a flow chart of the wastewater graded treatment process of the present invention. Figure 3 This is a flowchart of the intelligent scheduling process for recycling according to the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following description is provided in conjunction with the appendix. Figure 1-3 The present invention will be further described in detail with reference to specific embodiments.

[0019] Example 1: A wastewater classification, separation, and recycling system for a single workshop in a chemical enterprise This embodiment takes the industrial wastewater generated by the organic synthesis workshop of a chemical enterprise as the treatment object, and provides a detailed description of a specific implementation method of a wastewater classification and separation system based on industrial wastewater recycling.

[0020] The organic synthesis workshop generates approximately 500 cubic meters of wastewater daily. The wastewater sources include three categories: reactor condensate, equipment cleaning wastewater, and floor washing wastewater. The pollution levels of each type of wastewater vary significantly: reactor condensate contains a certain amount of residual organic solvents, with COD values ​​ranging from 200 to 800 mg / L. The equipment cleaning wastewater contains a high concentration of organic matter and a small amount of catalyst residue, with a COD value between 800 and 3000 mg / L; The wastewater from the ground washing is relatively lightly polluted, with a COD value between 100 and 200 mg / L and a pH value close to neutral.

[0021] Working process of wastewater collection and pretreatment module The wastewater collection and pretreatment module guides the three types of wastewater into the main inlet channel through the manifold pipes set at each water production point in the workshop. At the end of the main inlet channel, a bar screen with an effective aperture of 5mm is installed. The bar screen intercepts and removes fibrous impurities, solid particles, and floating matter from the wastewater. The wastewater filtered by the bar screen is then pumped by a booster pump at a flow rate not exceeding 60 cubic meters per hour to the buffer equalization tank at the inlet of the multi-parameter real-time water quality monitoring module. The buffer equalization tank has a volume of 30 cubic meters to balance the fluctuation of the wastewater inflow and ensure the stable operation of the subsequent monitoring module. The equalization tank is equipped with a stirring device with a rotation speed of 20 revolutions per minute to prevent the sedimentation of suspended solids in the wastewater, ensure the uniformity of the inflow water quality, and avoid excessively high local wastewater concentrations that could affect the accuracy of subsequent monitoring.

[0022] Working process of multi-parameter real-time water quality monitoring module The multi-parameter real-time water quality monitoring module is equipped with an online water quality sensor group on the effluent pipeline of the equalization tank to continuously monitor the following five key water quality indicators of the wastewater in real time: The first indicator is pH value, which is detected using an electrode-type pH sensor. The detection range is 0 to 14, with an accuracy of ±0.05. The data acquisition frequency is once every 10 seconds. It is used to determine the acid-base characteristics of wastewater. The pH value of lightly polluted wastewater is usually between 6.5 and 8.5, the pH value of moderately polluted wastewater may deviate to between 5.0 and 6.5 or between 8.5 and 9.5, and the pH value of heavily polluted wastewater may be lower than 5.0 or higher than 9.5.

[0023] The second indicator is Chemical Oxygen Demand (COD), which is detected using an online COD sensor based on ultraviolet spectrophotometry. The detection range is 0 to 5000 mg / L, with an accuracy of ±5%. Data is collected every 2 minutes. COD is a core indicator reflecting the degree of organic pollution in wastewater. The COD classification thresholds set for this system are: lightly polluted wastewater COD ≤ 300 mg / L, moderately polluted wastewater 300 mg / L < COD ≤ 1500 mg / L, and heavily polluted wastewater COD > 1500 mg / L.

[0024] The third indicator is suspended solids concentration (SS), which is indirectly detected and converted using an optical scattering turbidity sensor. The detection range is 0 to 2000 mg / L, with an accuracy of ±10%. The data acquisition frequency is once every 30 seconds. The SS classification thresholds set in this system are: lightly polluted wastewater SS≤100 mg / L, moderately polluted wastewater 100 mg / L<SS≤500 mg / L, and heavily polluted wastewater SS>500 mg / L.

[0025] The fourth indicator is ammonia nitrogen concentration ( The system employs an online ammonia nitrogen sensor using an ion-selective electrode method. The detection range is 0 to 100 mg / L, with an accuracy of ±5%. Data acquisition is performed every 5 minutes. The classification threshold is: slightly polluted wastewater ≤5mg / L, moderately polluted wastewater ≤5mg / L ≤25mg / L, heavily polluted wastewater >25mg / L.

[0026] The fifth indicator is the total amount of heavy metal ions, which is detected using an online sensor based on X-ray fluorescence spectroscopy. The detection targets include common industrial heavy metal ions such as copper, zinc, chromium, and nickel. The detection range is 0 to 50 mg / L, with an accuracy of ±10%. The data acquisition frequency is once every 10 minutes. The system sets the following thresholds for the total amount of heavy metal ions: lightly polluted wastewater with a total amount of heavy metal ions not exceeding 0.5 mg / L; moderately polluted wastewater with a total amount of heavy metal ions between 0.5 mg / L and 5 mg / L; and heavily polluted wastewater with a total amount of heavy metal ions exceeding 5 mg / L.

[0027] The detection data from each sensor is transmitted in real time to the comprehensive pollution classification judgment module via a 4-20mA standard current signal or an RS485 communication interface, with a transmission delay of no more than 1 second, ensuring the real-time acquisition of data by the judgment module.

[0028] Working process of the comprehensive pollution classification and determination module The comprehensive pollution grading module uses a weighted comprehensive scoring algorithm to comprehensively evaluate the detection data of five water quality indicators and calculate the comprehensive pollution index P. The formula for calculating the comprehensive pollution index P is as follows: ; The meanings of each parameter are as follows: , , , , These are pH value, COD, SS, The weighting coefficients corresponding to the total amount of heavy metal ions all range from 0 to 1 and satisfy the normalization condition: + + + + =1, based on the main pollution characteristics of chemical enterprise wastewater, the weight coefficients in this embodiment are taken as follows: =0.10, =0.40, =0.15, =0.20, =0.15, where the weighting coefficient of COD is... The highest value is 0.40, because organic pollution is the most important type of pollution in organic chemical wastewater, and COD can most directly reflect the degree of organic pollution. Weighting coefficients Secondly, the value is 0.20, which reflects the characteristics of nitrogen-containing organic matter decomposition in organic synthesis wastewater. The weighting coefficient is selected based on the historical water quality monitoring data of the enterprise's wastewater and the analysis conclusions of the main controlling factors of the environmental impact of this type of wastewater.

[0029] , , , , These are dimensionless scoring functions for each indicator, mapping the measured values ​​of each indicator to a scoring range of 0 to 10. This eliminates the dimensions of the five indicators, facilitating weighted summation. For example, its piecewise linear mapping rule is: when the measured COD value C satisfies C≤300mg / L, =C / 300×3, which means the maximum score is 3 points; When 300 mg / L < C ≤ 1500 mg / L, =3+(C-300) / 1200×4, meaning the score is between 3 and 7 points; When C > 1500 mg / L, =7+(C-1500) / 3500×3, but the maximum score is no more than 10 points. The scoring functions of the other indicators are similarly piecewise linearly mapped according to the corresponding threshold partitions. The specific parameters are determined according to the grading threshold of each indicator.

[0030] The classification rules for the comprehensive pollution index P are as follows: If P≤3, it is determined to be slightly polluted wastewater; If 3 < P ≤ 6, then it is determined to be moderately polluted wastewater; If P > 6, it is determined to be heavily polluted wastewater.

[0031] The above-mentioned classification thresholds are determined based on the provisions of the national industrial wastewater discharge standards for the treatment targets of wastewater of different pollution levels, as well as the tolerance range of the treatment process for the influent water quality. The calculation cycle for classification is 10 minutes, that is, every 10 minutes, a comprehensive score is calculated based on the average detection value within that time period and the judgment result is output, so as to reduce frequent switching caused by short-term water quality fluctuations.

[0032] After completing a comprehensive scoring calculation, the comprehensive pollution classification judgment module outputs the pollution level judgment result (light / moderate / severe) of the current wastewater batch as a digital signal to the separation control module, and simultaneously uploads the judgment result and the original detection data to the data acquisition and intelligent management module for recording and storage.

[0033] Working process of the separation control module The separation control module consists of a programmable logic controller (PLC) and three sets of electric butterfly valve control devices. The PLC receives the wastewater level instruction from the comprehensive pollution classification judgment module and drives the electric butterfly valve on the corresponding pipeline to act according to the preset valve control logic: if the judgment result is lightly polluted wastewater, the PLC instructs electric butterfly valve A to open and electric butterfly valves B and C to close, and the wastewater is introduced into the lightly polluted wastewater storage tank. If the determination result is moderately polluted wastewater, the PLC command B electric butterfly valve to open and A and C electric butterfly valves to close, and the wastewater is introduced into the moderately polluted wastewater storage tank. If the determination result is that the wastewater is heavily polluted, the PLC commands electric butterfly valve C to open and electric butterfly valves A and B to close, and the wastewater is introduced into the heavily polluted wastewater storage tank.

[0034] To prevent temporary cross-contamination during wastewater grade switching, the separation control module is equipped with a valve switching buffer delay mechanism: upon receiving a new grade switching command, the currently open valve is closed, and the target valve is opened after a 3-second delay. During this period, the influent booster pump is reduced to a minimum delivery flow of 5 cubic meters per hour to ensure that the residual wastewater in the pipeline is completely pushed to the corresponding storage tank before the valve switching is completed. The on / off feedback signal of the electric butterfly valve is transmitted back to the PLC in real time. The PLC can only resume normal flow operation after receiving the valve on / off confirmation signal. This closed-loop feedback mechanism ensures the reliability of the valve switching action.

[0035] Working process of hierarchical storage and buffer module The graded storage and buffer module is equipped with three independent and physically isolated storage tanks: a lightly polluted wastewater storage tank (100 cubic meters), a moderately polluted wastewater storage tank (150 cubic meters), and a heavily polluted wastewater storage tank (200 cubic meters). The heavily polluted wastewater storage tank has the largest volume. The design is based on the fact that the treatment cycle of heavily polluted wastewater is relatively long, and a larger buffer capacity is required to balance the flow difference between the influent and the treatment flow, and to prevent the tank from overflowing due to the treatment rate not being as fast as the influent rate.

[0036] Each storage tank is equipped with an ultrasonic level gauge to continuously monitor the liquid level within the tank with an accuracy of ±5mm. Data is uploaded to the data acquisition and intelligent control module every 30 seconds. When the liquid level in any storage tank reaches 90% of its design volume, the data acquisition and intelligent control module automatically triggers a high-level warning, notifying maintenance personnel to promptly initiate the corresponding treatment process to accelerate emptying. At the same time, the inflow rate of the corresponding wastewater is reduced to prevent the storage tank from overflowing. Each storage tank is separated by a seepage-proof partition wall made of reinforced concrete with an epoxy resin anti-corrosion coating on the inner wall to prevent cross-contamination of wastewater of different grades due to leakage from the tank body, ensuring the reliability of physical separation.

[0037] The working process of the hierarchical processing module For the three levels of wastewater, the graded treatment module adopts the following differentiated treatment processes: For lightly polluted wastewater, a two-step treatment process of "precision filtration + ultraviolet disinfection" is adopted. The precision filtration unit uses an ultrafiltration membrane module with a pore size of 0.1μm, an operating pressure of 0.1 to 0.3MPa, an operating temperature range of 5 to 40℃, and a single treatment capacity of 50 cubic meters per hour. The ultrafiltration membrane module is cleaned periodically by backwashing, with a backwash cycle of once every 30 minutes of operation and a backwash duration of 60 seconds. The backwash pressure is 1.5 times the normal operating pressure to maintain the stability of membrane flux. After filtration, the wastewater enters the ultraviolet disinfection unit, which uses a low-pressure ultraviolet lamp array with an ultraviolet irradiation dose of not less than 40mJ / cm². 2 The wastewater contact time in the disinfection unit is no less than 30 seconds. After the above two steps of treatment, the effluent quality can meet the reuse requirements of industrial cooling water and site flushing water. The specific effluent indicators are COD≤50mg / L, SS≤10mg / L, and pH value between 6.5 and 8.5.

[0038] For moderately polluted wastewater, a two-step treatment process of "coagulation sedimentation + aeration biochemical treatment" is adopted. In the coagulation sedimentation unit, polyaluminum chloride (PAC) is added to the wastewater as a coagulant at a dosage of 100 to 300 mg / L. The specific dosage is dynamically adjusted according to the measured turbidity of the batch of wastewater. Simultaneously, polyacrylamide (PAM) is added as a coagulant aid at a dosage of 1 to 3 mg / L. The order of addition of coagulant and coagulant aid is as follows: first, add PAC and mix rapidly at a stirring speed of 100 rpm for 2 minutes; then add PAM and stir slowly at a stirring speed of 30 rpm for 5 minutes. After that, the mixture is transferred to a sedimentation tank for settling for 2 hours. The surface hydraulic load of the sedimentation tank should not exceed 1.5 m. 3 / (m 2 (h) The effluent from coagulation and sedimentation enters the aeration biological treatment unit, where the activated sludge process is used. The hydraulic retention time (HRT) in the aeration tank is 8 to 12 hours, the dissolved oxygen (DO) concentration is maintained at 2 to 4 mg / L, the sludge return ratio is 50% to 100%, and the mixed liquor suspended solids (MLSS) concentration is 2000 to 4000 mg / L. After the above two steps of treatment, the effluent COD is ≤100 mg / L. ≤10mg / L, SS≤20mg / L, meeting the water quality requirements for recycled water in production processes such as product cleaning and process cooling.

[0039] For heavily polluted wastewater, a four-step treatment process of "chemical precipitation + advanced oxidation + aeration and biochemical treatment + deep filtration" is adopted. In the chemical precipitation unit, lime milk (Ca(OH)2 aqueous solution with an effective concentration of 5%) is added to the wastewater to adjust the pH value of the wastewater to 10.5 to 11.5, so that the heavy metal ions (copper, zinc, chromium, nickel, etc.) in the wastewater precipitate out in the form of corresponding hydroxides. The precipitation time is 2 to 3 hours. After chemical precipitation, the supernatant undergoes a pH adjustment unit to bring the pH back to 6.5-7.5 before entering the advanced oxidation unit. This unit employs an ozone / hydrogen peroxide (O3 / H2O2) combined advanced oxidation process. The ozone dosage is 20-50 mg / L (based on liquid phase concentration), and the hydrogen peroxide (30% concentration) dosage is 5-15 mL / L, with a molar ratio maintained at O3:H2O2 = 1:0.5. The ozone contact time is 15-30 minutes. Throughout the advanced oxidation stage, the pH is maintained between 6.0 and 7.0. The advanced oxidation process utilizes the strong oxidizing effect of hydroxyl radicals (·OH) to oxidize and decompose the recalcitrant organic pollutants in the wastewater, increasing the BOD5 / COD ratio from 0.1-0.2 before treatment to over 0.3, thereby significantly improving the biodegradability of the wastewater. The advanced oxidation process creates favorable conditions for subsequent aeration and biological treatment. Wastewater treated with advanced oxidation enters the aeration and biological treatment unit. The process parameters are basically the same as those for moderately polluted wastewater, but the hydraulic retention time is extended to 16 to 24 hours to ensure sufficient biochemical degradation time for recalcitrant organic matter. The effluent from the biological treatment is finally treated by a deep filtration unit. This unit consists of a quartz sand filter layer (thickness 0.8 to 1.2 m, effective particle size 0.5 to 1.0 mm, filtration rate 8 to 10 m / h) and an activated carbon adsorption layer (effective particle size 1.0 to 2.0 mm, empty bed contact time EBCT 10 to 15 minutes) stacked on top of each other. Sand filtration removes residual suspended solids, and activated carbon adsorption removes residual trace organic matter and color. After these four steps, the effluent COD ≤ 50 mg / L and the total heavy metal ion concentration ≤ 0.5 mg / L. ≤5mg / L, meeting the higher requirements for reuse standards in production processes or compliance with discharge standards.

[0040] The working process of recycling intelligent scheduling module The intelligent scheduling module for recycling receives real-time water quality data from online sensors at each outlet of the tiered treatment module, as well as real-time water demand data from the water application management system for each production process. Based on the following scheduling logic, it dynamically formulates a recycled water allocation plan: The scheduling module pre-establishes water quality requirement files for each production process. The files clearly record the allowable upper limits for five indicators: COD, SS, pH value, total heavy metal ions, and ammonia nitrogen concentration for each process. The scheduling module compares the measured water quality data of each grade of recycled water with the water quality requirement files of each process item by item, and selects a list of target processes that meet the water quality requirements. Under the premise of meeting the water quality requirements, the scheduling module generates the optimal allocation plan based on the scheduling principle of "prioritizing allocation to processes with high demand and tight water use cycles" and the current storage data of the recycled water storage tank. By controlling the opening of the electric regulating valve on the recycled water distribution pipeline, the corresponding grade of recycled water is directed to the target process.

[0041] Taking the specific operating data of this embodiment as an example: the lightly treated recycled water (COD≤50mg / L, SS≤10mg / L) is preferentially allocated to the cooling tower circulating cooling water replenishment in the plant area (daily water demand of about 100 cubic meters) and the washing of the plant area roads and ground (daily water demand of about 30 cubic meters). Moderately treated reclaimed water (COD ≤ 100 mg / L) ≤10mg / L) is allocated to the equipment outer surface cleaning process (daily water requirement is approximately 50 cubic meters); The heavily polluted wastewater that has undergone deep treatment (COD≤50mg / L, total heavy metals≤0.5mg / L) is recycled and allocated to the intermediate cleaning process of the product with high water quality requirements (the daily water demand is about 80 cubic meters). Through the above-mentioned tiered and targeted allocation, the industrial wastewater recycling rate of this chemical enterprise can reach about 72% of the daily wastewater production in this embodiment, which significantly reduces the consumption of fresh water and the amount of wastewater discharged.

[0042] Working process of data acquisition and intelligent control module The data acquisition and intelligent control module consists of an industrial-grade data acquisition server, a human-machine interface (HMI), and an industrial Ethernet communication network. The data acquisition server is interconnected with the PLCs and sensors of each functional module through the industrial Ethernet. The data acquisition cycle is set according to the update frequency of different types of data. The acquisition cycle of real-time sensor data is 10 seconds to 5 minutes, and the acquisition cycle of equipment status data is 30 seconds.

[0043] The main functions of the data acquisition and intelligent management module include the following aspects: In terms of real-time monitoring, the HMI displays the liquid level of each storage tank, the readings of each water quality detection sensor, the status of each electric valve, the operating parameters of each treatment unit, and the current wastewater classification and treatment statistics in real time through a graphical interface, so that operation and maintenance personnel can intuitively grasp the overall operating status of the system. Regarding the abnormal warning function, the module presets the normal operating range of each sensor's detection value. When any detection value exceeds the preset range, the system automatically triggers an audible and visual alarm and sends a warning notification to the designated maintenance personnel's mobile phone via SMS or push notification to ensure that abnormal situations are responded to in a timely manner. In terms of historical data management, the system automatically stores the operation data records of each module, and the historical data is kept for no less than 3 years. It supports querying and retrieving by time period and by indicator type, and automatically generates daily, weekly and monthly statistical reports to provide data support for the supervision and auditing of enterprise wastewater treatment. In terms of parameter optimization, the data acquisition and intelligent management module regularly performs statistical analysis on historical operating data, automatically compares the correlation between each treatment process parameter and the effluent water quality compliance status, and provides operation and maintenance personnel with suggestions for adjusting operating parameters in order to continuously optimize the system's treatment efficiency and reduce operating energy consumption and reagent costs.

[0044] Example 2: A multi-workshop integrated wastewater classification, separation, and recycling system for a metallurgical enterprise This embodiment takes the combined wastewater from three workshops—rolling mill, pickling workshop, and electroplating workshop—of a metallurgical enterprise as the treatment object, and describes the specific implementation of a wastewater classification and separation system based on industrial wastewater recycling in a complex wastewater scenario involving multiple workshops.

[0045] The metallurgical enterprise generates a total of about 1,200 cubic meters of wastewater per day from its three workshops. The characteristics of the wastewater are as follows: the cooling wastewater from the steel rolling workshop is slightly polluted, with the main pollutants being emulsified oil and suspended iron filings. The COD value is between 150 and 400 mg / L, and the SS value is between 50 and 200 mg / L. The pickling workshop wastewater is moderately to heavily polluted wastewater, containing hydrochloric acid and sulfuric acid residues and iron ions, with a pH value between 1.5 and 3.5 and a COD value between 500 and 2000 mg / L; The wastewater from the electroplating workshop is heavily polluted, containing heavy metal ions such as chromium, nickel, and copper, with a total heavy metal concentration between 10 and 80 mg / L. It also contains a certain amount of cyanide residue, making it a complex wastewater with a high degree of hazard.

[0046] In view of the special pollution characteristics of the wastewater mentioned above, the wastewater classification and separation system in this embodiment, while maintaining the same basic architecture as Embodiment 1, has been specifically adjusted in the following aspects: In the multi-parameter real-time water quality monitoring module, an online total cyanide detection sensor has been added. The detection principle is flow injection colorimetry, the detection range is 0 to 10 mg / L, the detection accuracy is ±10%, and the data acquisition frequency is once every 5 minutes. It is used to identify cyanide-containing electroplating wastewater. At the same time, the detection threshold for total heavy metal ions has been increased from 50 mg / L to 100 mg / L to adapt to the actual situation of high heavy metal concentration in electroplating wastewater.

[0047] In the comprehensive pollution classification module, the weighting coefficients of each indicator have been adjusted, with the weighting coefficient for total heavy metal ions increased to [value missing]. =0.25, and added the total cyanide detection index f(CN) - ) and their corresponding weights =0.10, the sum of all weight coefficients still satisfies the normalization condition ( + + + + + =1), and adjust the remaining weight coefficients accordingly. =0.05, =0.35, =0.10, =0.15, to reflect the actual situation that heavy metals and cyanide are the main pollution control factors in metallurgical wastewater. In addition, a mandatory judgment rule is set for cyanide-containing wastewater: when the total cyanide concentration is detected to exceed 0.5 mg / L, regardless of the calculated value of the comprehensive pollution index P, the batch of wastewater is forcibly judged as heavily polluted wastewater. This is to prevent the comprehensive score result from misjudging cyanide-containing wastewater as moderately or lightly polluted wastewater when the cyanide concentration is relatively low and other indicators are also low, thus ensuring the safe disposal of cyanide-containing wastewater.

[0048] In the graded treatment module, for heavily polluted wastewater containing cyanide, an alkaline chlorination pretreatment unit is added before the chemical precipitation process. The specific process parameters for the cyanide pretreatment are as follows: sodium hypochlorite (NaClO, with an effective chlorine concentration of not less than 10%) is added to the wastewater at a mass ratio of effective chlorine to cyanide of not less than 3:1. An oxidation process is carried out under alkaline conditions with a pH of 10 to 11 for 15 to 20 minutes to remove the cyanide (CN). - ) is oxidized to cyanate (CNO) - ), to achieve a stage of cyanide breaking; The wastewater pH was then adjusted to 7-8, and sodium hypochlorite was added to ensure the available chlorine to cyanate mass ratio was not less than 4:1. A second-stage oxidation process was then carried out under neutral to weakly alkaline conditions for 30-45 minutes to remove the cyanate (CNO3). -The cyanide is further oxidized and decomposed into carbon dioxide (CO2) and nitrogen (N2) to achieve complete harmless treatment of cyanide-containing wastewater. After the cyanide destruction treatment, the total cyanide concentration in the wastewater should be less than 0.2 mg / L. Only after confirming that the safe concentration has been reached can the wastewater enter the subsequent chemical precipitation unit for further treatment.

[0049] Through the above-mentioned targeted adjustments, the wastewater classification and separation system of this embodiment can effectively meet the classification and separation treatment needs of complex wastewater from multiple workshops in metallurgical enterprises. In terms of intelligent scheduling for recycling and utilization, the lightly treated cooling wastewater from the rolling mill workshop is reused as direct cooling water for the rolling process (approximately 300 cubic meters per day). After being neutralized and meeting standards, the moderately treated pickling wastewater is reused for irrigation of green areas and dust suppression on roads within the factory area (approximately 200 cubic meters per day). The deeply treated electroplating wastewater is reused for rinsing workpieces in the pre-plating process (approximately 150 cubic meters per day). In this embodiment, the comprehensive wastewater recycling rate of the metallurgical enterprise can reach approximately 65% ​​of the daily wastewater production, realizing the efficient resource utilization of complex industrial wastewater in a tiered manner.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wastewater classification and separation system based on industrial wastewater recycling, characterized in that, The system includes a wastewater collection and pretreatment module, a multi-parameter water quality real-time detection module, a comprehensive pollution classification and judgment module, a separation control module, a graded storage and buffer module, a graded treatment module, a recycling intelligent scheduling module, and a data collection and intelligent management and control module. The wastewater collection and pretreatment module removes suspended solids and floating impurities with a particle size greater than 5mm from the wastewater through a bar screen filter. After completing the preliminary pretreatment, the wastewater is transported to the multi-parameter water quality real-time detection module. The multi-parameter real-time water quality detection module performs real-time online detection of five water quality indicators of wastewater: pH value, chemical oxygen demand, suspended solids concentration, ammonia nitrogen concentration, and total heavy metal ions, and transmits the detection data to the comprehensive pollution classification and judgment module in real time. The comprehensive pollution classification judgment module, based on the built-in classification threshold system, maps the measured values ​​of the five water quality indicators to a unified scoring range of 0 to 10 through a piecewise linear dimensionless scoring function. After eliminating the difference in dimensions, it performs weighted summation to calculate the comprehensive pollution index, classifies the wastewater into three levels: lightly polluted wastewater, moderately polluted wastewater, and heavily polluted wastewater, and sends the classification result instruction to the separation control module in real time. The separation control module drives the electric regulating valve and pipeline switching device to operate according to the received wastewater level instructions, so as to accurately guide wastewater of different levels to the corresponding independent storage areas, thereby achieving complete physical separation between the three levels of wastewater. The graded storage and buffer module includes independent storage tanks corresponding to three pollution levels. Each storage tank is equipped with a liquid level sensor to monitor the storage status in real time and feed the liquid level data back to the data acquisition and intelligent control module. The graded treatment module adopts differentiated treatment processes for different levels of wastewater. Lightly polluted wastewater enters the lightly polluted reclaimed water storage tank after being treated by precision filtration and ultraviolet disinfection. Moderately polluted wastewater enters the moderately polluted reclaimed water storage tank after being treated by coagulation sedimentation and aeration biochemical treatment. Heavyly polluted wastewater enters the heavyly polluted reclaimed water storage tank after being treated by four processes: chemical precipitation, advanced oxidation, aeration biochemical treatment and deep filtration. The intelligent scheduling module for recycling dynamically formulates a recycling water allocation plan based on the actual water quality of each level of recycled water and the real-time water demand of each production process, and directs the recycled water of each level to the production process that matches the water quality demand. The data acquisition and intelligent management module summarizes the operating status data of each module in real time, monitors the overall operation of the system, provides early warning of anomalies and remote management, and supports the storage and statistical analysis of historical data.

2. The wastewater classification and separation system according to claim 1, characterized in that, The multi-parameter real-time water quality detection module sets the following thresholds for pH values: slightly polluted wastewater has a pH value between 6.5 and 8.5; moderately polluted wastewater has a pH value between 5.0 and 6.5 / 8.5 and 9.5; and heavily polluted wastewater has a pH value below 5.0 / above 9.

5. The threshold values ​​for chemical oxygen demand (COD) classification are as follows: COD of lightly polluted wastewater is no higher than 300 mg / L; COD of moderately polluted wastewater is higher than 300 mg / L but no higher than 1500 mg / L; and COD of heavily polluted wastewater is higher than 1500 mg / L. The classification thresholds for suspended solids concentration are as follows: suspended solids concentration in lightly polluted wastewater is not higher than 100 mg / L; suspended solids concentration in moderately polluted wastewater is higher than 100 mg / L but not higher than 500 mg / L; and suspended solids concentration in heavily polluted wastewater is higher than 500 mg / L. The threshold values ​​for ammonia nitrogen concentration are as follows: ammonia nitrogen concentration in lightly polluted wastewater is no higher than 5 mg / L; ammonia nitrogen concentration in moderately polluted wastewater is higher than 5 mg / L but no higher than 25 mg / L; and ammonia nitrogen concentration in heavily polluted wastewater is higher than 25 mg / L. The thresholds for classifying the total amount of heavy metal ions are as follows: the total amount of heavy metal ions in lightly polluted wastewater is no higher than 0.5 mg / L; the total amount of heavy metal ions in moderately polluted wastewater is higher than 0.5 mg / L but no higher than 5 mg / L; and the total amount of heavy metal ions in heavily polluted wastewater is higher than 5 mg / L.

3. The wastewater classification and separation system according to claim 1, characterized in that, The comprehensive pollution classification and judgment module uses a weighted comprehensive scoring algorithm to calculate the comprehensive pollution index. Each water quality indicator is mapped to the scoring range of 0 to 10 through the corresponding piecewise linear dimensionless scoring function and then weighted and summed. The sum of the weight coefficients of each indicator satisfies the normalization condition. The classification rules for the comprehensive pollution index are as follows: when the comprehensive pollution index is not higher than 3, it is classified as lightly polluted wastewater; when the comprehensive pollution index is higher than 3 but not higher than 6, it is classified as moderately polluted wastewater; and when the comprehensive pollution index is higher than 6, it is classified as heavily polluted wastewater. The calculation cycle is 10 minutes. Each time, the comprehensive score is calculated based on the average detection value within this time period, and the judgment result is output.

4. The wastewater classification and separation system according to claim 1, characterized in that, The separation control module consists of a programmable logic controller and three sets of electric butterfly valve control devices. The programmable logic controller drives the electric butterfly valves on the corresponding pipelines to operate according to the wastewater level instructions. Each time, only one set of electric butterfly valves corresponding to the current wastewater level is opened, while the other two sets remain closed. The separation control module is equipped with a valve switching buffer delay mechanism. After receiving a new level switching command, it first closes the currently open valve, delays for 3 seconds, and then opens the target valve. During this period, the water inlet booster pump is reduced to a delivery flow rate of 5 cubic meters per hour. The on / off feedback signal of the electric butterfly valve is transmitted back to the programmable logic controller in real time. The programmable logic controller can only resume normal flow operation after receiving the valve on / off confirmation signal.

5. The wastewater classification and separation system according to claim 1, characterized in that, In the graded storage and buffer module, a seepage-proof partition wall is set between the three independent storage pools. The wall is made of reinforced concrete and the inner wall is coated with an epoxy resin anti-corrosion coating. Each storage tank is equipped with an ultrasonic level gauge to continuously monitor the liquid level in the tank. When the liquid level in any storage tank reaches 90% of the designed volume, the data acquisition and intelligent control module automatically triggers a high liquid level warning and simultaneously reduces the influent flow rate of the corresponding level of wastewater.

6. The wastewater classification and separation system according to claim 1, characterized in that, In the graded treatment module, the precision filtration unit for lightly polluted wastewater uses an ultrafiltration membrane module with a pore size of 0.1 μm, and the ultraviolet disinfection unit has an ultraviolet irradiation dose of not less than 40 mJ / cm². 2 The contact time of wastewater in the disinfection unit shall not be less than 30 seconds; The coagulation and sedimentation unit for moderately polluted wastewater uses polyaluminum chloride as a coagulant and polyacrylamide as a coagulant aid. The effluent from the coagulation and sedimentation enters the aeration and biological treatment unit using the activated sludge process, with a hydraulic retention time of 8 to 12 hours. The advanced oxidation unit for heavily polluted wastewater adopts a combination of ozone and hydrogen peroxide advanced oxidation process. The deep filtration unit consists of a quartz sand filter layer and an activated carbon adsorption layer stacked together. After four treatment processes, the chemical oxygen demand of the effluent is no higher than 50 mg / L and the total amount of heavy metal ions is no higher than 0.5 mg / L.

7. The wastewater classification and separation system according to claim 1, characterized in that, The intelligent scheduling module for recycling pre-establishes water quality requirements files for each production process. The files record the allowable upper limits for five indicators for each process: chemical oxygen demand, suspended solids concentration, pH value, total heavy metal ions, and ammonia nitrogen concentration. The intelligent scheduling module for recycling compares the measured water quality data of each level of recycled water with the water quality demand files of each process item by item, selects the target processes that meet the water quality requirements, and generates an allocation plan based on the scheduling principle of prioritizing allocation to processes with insufficient current water application reserves and high single water demand. It also generates an allocation plan by combining the current storage data of the recycled water storage tank and directs the corresponding level of recycled water to the target production process by controlling the opening of the electric regulating valve on the recycled water allocation pipeline.

8. The wastewater classification and separation system according to claim 1, characterized in that, The multi-parameter real-time water quality detection module also includes an online total cyanide detection sensor; The comprehensive pollution classification and judgment module sets a mandatory judgment rule for cyanide-containing wastewater: when the total cyanide concentration is detected to exceed 0.5 mg / L, regardless of the calculated value of the comprehensive pollution index, the batch of wastewater is forcibly judged as heavily polluted wastewater. For cyanide-containing wastewater identified as heavily polluted, the graded treatment module adds an alkaline chlorination pretreatment unit before the chemical precipitation process. Sodium hypochlorite is added to the wastewater, and a first-stage oxidation is carried out under alkaline conditions with a pH of 10 to 11 to oxidize cyanide into cyanate. Then, the pH of the wastewater is adjusted to 7 to 8, and sodium hypochlorite is added again for a second-stage oxidation to further oxidize and decompose the cyanate into carbon dioxide and nitrogen. Only when the total cyanide concentration in the wastewater is below 0.2 mg / L after the cyanide-breaking treatment can it enter the subsequent chemical precipitation unit.

9. The wastewater classification and separation system according to claim 1, characterized in that, The data acquisition and intelligent control module consists of an industrial-grade data acquisition server, a human-machine interface, and an industrial Ethernet communication network. The data acquisition server is interconnected with the programmable logic controllers and sensors of each functional module through the industrial Ethernet. The data acquisition and intelligent management module has four functions: real-time monitoring, anomaly warning, historical data management and parameter optimization. The historical data is stored for no less than 3 years. When any detection value exceeds the preset range, the system automatically triggers an audible and visual alarm and sends a warning notification to the designated maintenance personnel.

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