A method and system for treating electroplating wastewater

Abstract

The application provides a treatment method and system for electroplating wastewater, and relates to the technical field of wastewater treatment.The original absorbance data of a clean sample is collected, and after quantitative comparison, the net absorbance reflecting the true absorption of the complex on the characteristic wavelength is obtained, the influence degree of small particle suspensions on the signal is reduced, and a standard curve is calibrated.The net absorbance after double-beam correction is combined with the standard curve for joint analysis, and then the equivalent concentration of the complex is inversely calculated through the net absorbance, so that the accuracy and stability are improved.Multiple variables such as the equivalent concentration of the complex, the wastewater volume flow, the effective chlorine mass concentration and the temperature are coupled for feedforward dosing control, a dosing flow is generated by using a thermodynamic correction formula, dosing is changed from passive response to active prediction, the continuity and accuracy of the dosing amount can be maintained, the risk of excessive and waste of the medicament is reduced, and the stability of the effluent and the oxidation treatment efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a method and system for treating electroplating wastewater. Background Technology

[0002] Electroplating wastewater originates from the metal plating and cleaning processes. It contains a variety of pollutants, is highly concentrated, strongly ionic, and often contains complexes. Due to its high toxicity and recalcitrant nature, it must undergo multi-stage treatment before being discharged.

[0003] In the control of oxidation dosing in electroplating wastewater treatment, traditional methods often use single-band absorbance for quantitative analysis, which is easily affected by turbidity, baseline drift, and other factors. At the same time, they are mostly based on single-variable feedback control, which is difficult to effectively cope with the rapid fluctuations in wastewater influent load and the uncertainty brought about by temperature changes. This can easily lead to lag, under-dosing, or over-dosing, thus affecting stability and treatment effect.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for treating electroplating wastewater, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for treating electroplating wastewater, comprising the following steps: S1. Physically filter the electroplating wastewater to be treated and collect clean samples; S2. The clean sample is introduced into a quartz flow cell and subjected to dual-beam ultraviolet detection to collect raw absorbance data. The raw absorbance data includes characteristic wavelength absorbance and reference wavelength absorbance. The characteristic wavelength absorbance is used to reflect the mixed effect of chemical absorption and scattering, and the reference wavelength absorbance is used to reflect the scattering effect of suspended particles in the water. S3. Perform dual-wavelength scattering correction on the original absorbance data to generate net absorbance, which is used to reflect the true absorption of the complex at the characteristic wavelength. S4. Based on the standard curve, the net absorbance is inverted to generate the equivalent concentration of the complex. The standard curve is established in the following way: a standard solution with a known gradient is prepared by selecting a complexing agent, and the absorbance response of each standard solution is collected based on the same optical path of dual-beam ultraviolet detection. The standard curve is constructed by linear fitting with the concentration of the standard solution as the true value and the corresponding absorbance response as the dependent variable. S5. Based on the correlation analysis of the complex equivalent concentration, wastewater flow rate, available chlorine mass concentration and temperature data, generate the dosing flow rate; S6. Add oxidant based on the dosing flow rate and perform sedimentation separation to obtain supernatant and sludge.

[0007] Furthermore, the physical filtration is used to filter fiber fragments and suspended particles in electroplating wastewater, the characteristic wavelength is 254nm, and the reference wavelength is 700nm.

[0008] Furthermore, the raw absorbance data is subjected to dual-wavelength scattering correction to generate net absorbance. The formula used is: ; Absorbance at characteristic wavelength For characteristic wavelength, For the reference wavelength absorbance, For reference wavelength, The scattering ratio coefficient, The background intercept.

[0009] Furthermore, the linear fitting formula is as follows: ; in, The calibrated slope is used to reflect the light absorption capacity of a unit concentration of complex under a unit optical path length. To calibrate the intercept, used to correct the optical background of the flow cell; It is the optical path length; This represents the concentration of the standard solution.

[0010] Furthermore, the net absorbance is inverted based on the standard curve, and the inversion formula used is as follows: ; in, This is the equivalent concentration of the complex, used to characterize the total equivalent amount of complexes to be oxidized in the wastewater.

[0011] Furthermore, the feedforward control formula with fusion thermodynamic correction is used to calculate the dosing flow rate. Based on the correlation analysis of complex equivalent concentration, wastewater flow rate, available chlorine mass concentration, and temperature data, the dosing flow rate is generated. ; in, The dosage flow rate is used to control the output frequency of the metering pump. These are stoichiometric coefficients, used to determine the number of moles of chlorine required to oxidize a single complex. This is the wastewater volumetric flow rate, used to calculate the treatment load per unit time. β is the effective chlorine mass concentration, used to reflect the true effective component content of the oxidant; β is the apparent temperature sensitivity coefficient, used to quantify the degree of influence of temperature on the oxidation reaction rate. This is for real-time temperature monitoring of on-site operating conditions. To calibrate the reference temperature, used to characterize the base temperature. As a safety factor, a dosing margin is introduced to the feedforward reference dosage to compensate for the underdosing risk caused by fluctuations in influent concentration and flow rate, optical inversion errors, and non-uniform mixing in the reaction zone.

[0012] Furthermore, a redox potential safety threshold is set. When the redox potential is detected to be higher than the safety threshold, the dosing flow rate is attenuated and corrected, and the corrected dosing flow rate is limited to a preset upper limit value. The upper limit value is set based on the metering pump and the drug storage tank.

[0013] Furthermore, the dual-beam ultraviolet detection is performed in a self-cleaning flow cell. When the absorbance of the reference wavelength drifts relative to the zero-point reference by more than a preset threshold, self-cleaning is triggered. The self-cleaning includes high-pressure gas backflushing and acidic solution circulation cleaning.

[0014] Furthermore, the pH of the wastewater is adjusted to between 9.0 and 10.5, flocculants are added to generate flocs, and solid-liquid separation is performed.

[0015] This invention also discloses a treatment system for electroplating wastewater, used to perform a method for treating electroplating wastewater, comprising: The pretreatment module is used to physically filter the electroplating wastewater to be treated and to collect clean samples. The detection module is used to introduce clean samples into a quartz flow cell for dual-beam ultraviolet detection and to collect raw absorbance data. The raw absorbance data includes characteristic wavelength absorbance and reference wavelength absorbance. The characteristic wavelength absorbance is used to reflect the mixed effect of chemical absorption and scattering, and the reference wavelength absorbance is used to reflect the scattering effect of suspended particles in the water. The signal processing module is used to perform dual-wavelength scattering correction on the raw absorbance data to generate net absorbance, which reflects the true absorption of the complex to the characteristic wavelength. The complex determination module is used to invert the net absorbance based on the standard curve to generate the complex equivalent concentration. The standard curve is established by selecting a complexing agent to prepare a standard solution with a known gradient, collecting the absorbance response of each standard solution based on the same optical path of dual-beam ultraviolet detection, and performing linear fitting with the concentration of the standard solution as the true value and the corresponding absorbance response as the dependent variable to construct and obtain the standard curve. The dosing control module is used to perform correlation analysis based on the equivalent concentration of the complex, wastewater flow rate, available chlorine mass concentration and temperature data, and generate the dosing flow rate. The sedimentation treatment module is used to add oxidant based on the dosing flow rate and perform sedimentation separation to obtain supernatant and sludge.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention acquires the net absorbance, reflecting the true absorption of the complex at characteristic wavelengths, by collecting the raw absorbance data of clean samples and performing quantitative comparison. This reduces the influence of small particulate matter on the signal. Simultaneously, a standard curve is calibrated, and the net absorbance after dual-beam correction is analyzed in conjunction with the standard curve. The net absorbance is then used to invert the equivalent concentration of the complex, improving accuracy and stability. Furthermore, the acquired equivalent concentration of the complex, wastewater volumetric flow rate, available chlorine mass concentration, and temperature are coupled together for feedforward dosing control. A thermodynamic correction formula is used to generate the dosing flow rate, shifting dosing from a passive response to active prediction. This maintains the continuity and accuracy of dosing, reduces the risk of overdosing and waste, and improves effluent stability and oxidation treatment efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall method flow of the present invention; Figure 2 This is a schematic diagram of the system modules of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0020] Example: Please refer to Figure 1 The present invention provides a technical solution: A method for treating electroplating wastewater, comprising the following steps: Step 1: Physically filter the electroplating wastewater to be treated and collect a clean sample; Physical filtration is used to filter fiber fragments and suspended particles in electroplating wastewater. The electroplating rinsing and replacement wastewater in the equalization tank is passed through an 80μm grid to remove fiber fragments, and then through a 50μm security filter to remove most of the suspended particles. The particle load of the sample stream to be used for online detection is controlled at a low level, reducing the risk of interference from turbidity and particle scattering, improving the stability and accuracy of net absorbance calculation, and thus improving the reliability of complex equivalent concentration inversion. The sample stream is used for detection in step 2.

[0021] Step 2: The clean sample is introduced into a quartz flow cell and subjected to dual-beam ultraviolet detection to collect raw absorbance data. The raw absorbance data includes characteristic wavelength absorbance and reference wavelength absorbance. The characteristic wavelength absorbance is used to reflect the contribution of the clean sample to chemical absorption and the mixed effect of scattering, while the reference wavelength absorbance is used to reflect the scattering effect of suspended particles in the water. The characteristic wavelength is 254 nm, and the reference wavelength is 700 nm. The chemical absorption information of the complex in the near-ultraviolet region is obtained through the absorbance signal at 254 nm. At the same time, the reference absorbance signal at 700 nm is used to quantify particle scattering and turbidity, achieving a preliminary distinction between absorption and scattering, thereby improving the accuracy and stability of the inversion.

[0022] In electroplating wastewater, the target is not the heavy metal ions themselves, but the complexing agents that encapsulate the metals. These complexing agents possess conjugated systems composed of carbon-nitrogen and carbon-oxygen double bonds, exhibiting strong electron orbital transition absorption in the deep ultraviolet region (190 nm-280 nm). Below 220 nm, although absorption is stronger, it is easily intercepted by the electronic vibrations of dissolved inorganic salts and the solvent itself, leading to signal saturation or distortion. Above 300 nm, the electronic absorption of the complexing agents drops sharply, resulting in a weak signal that is easily drowned out by turbidity noise. The chemical absorption cross-section of the complexed pollutants reaches near its peak at 254 nm. At 700 nm, the complexing agents do not absorb light, and small suspended particles in the wastewater, such as colloids, micro-sludge, and oil droplets, do not absorb light, but they cause elastic scattering. In the visible-near-infrared region, the scattering effect changes relatively gently with wavelength. The absorbance signal at 700 nm is used to measure the scattering of suspended particles. Specifically, the complex exhibits significant electronic transition absorption at 254 nm, and the signal intensity varies with the complex concentration and the absorbing components in the optical path. At 700 nm, there is almost no absorption by the complex, but it is affected by scattering from suspended particles, and therefore can be used as a reference. Compared to single-wavelength online detection, dual-beam detection, by simultaneously acquiring absorption and scattering signals, can better distinguish between signals caused by chemical absorption and turbidity, reducing misjudgments due to turbidity fluctuations.

[0023] The optical path length of the quartz flow cell was initially set to 10 mm. A clean sample was flowed through the quartz flow cell at a constant flow rate. Dual-beam ultraviolet detection was used to collect the absorbance at the characteristic wavelength and the absorbance at the reference wavelength. When the value exceeds 0.95 AU, it is considered to be out of range. It is necessary to ensure the safety and controllability of subsequent measurements and chemical treatment by using high-concentration bypass dilution in the influent or low-load limited dosing of the metering pump. Bypass dilution is performed by using pure water without complexes to dilute the clean sample at a fixed ratio. After dilution, the sample is sent back to the quartz flow cell for dual-beam UV detection. The true net absorbance of the original water sample and the equivalent concentration of the complex are calculated in reverse based on the dilution ratio. Low-load limited dosing of the metering pump is performed by temporarily locking the upper limit of the dosing flow rate during the dilution detection. The temporary upper limit is 60% of the rated maximum dosing amount. After the dilution detection is completed and the equivalent concentration of the complex is calculated, the limit is released and the feedforward control formula is switched to calculate the dosing flow rate.

[0024] Dual-beam UV detection is performed in a self-cleaning flow cell. Self-cleaning is triggered when the absorbance at the reference wavelength drifts beyond a preset threshold relative to the zero-point reference. Self-cleaning includes high-pressure gas backflushing and acidic solution circulation cleaning. The absorbance at the reference wavelength, measured and recorded during pure water calibration, serves as the zero-point reference. If the absorbance at the reference wavelength consistently exceeds the zero-point reference value by 0.02 AU for one minute, it is considered that the optical window is dirty, triggering self-cleaning to remove colloidal dirt and metal deposits from the optical window and stabilize the baseline.

[0025] Step 3: Perform dual-wavelength scattering correction on the raw absorbance data to generate net absorbance. Net absorbance is used to reflect the true absorption of the complex at the characteristic wavelength. This separates the signal interference from particle scattering from the chemical absorption signal, thus more accurately reflecting the absorption of light by the complex. The raw absorbance data is subjected to dual-wavelength scattering correction to generate net absorbance. The formula used is: ; The net absorbance obtained after dual-wavelength correction reflects the true chemical absorption intensity of the complex at the characteristic wavelength, eliminating interference from scattering coupling and optical path baseline drift. This provides a more accurate and repeatable input for subsequent quantitative inversion, improving the reliability of online monitoring. Absorbance at characteristic wavelength For characteristic wavelength, For the reference wavelength absorbance, For reference wavelength, This is the scattering ratio coefficient, used to quantify the coupling ratio of the reference wavelength scattering to the absorbance of the characteristic wavelength. The background intercept is used to compensate for baseline drift in the optical path.

[0026] By setting a scattering ratio coefficient, the coupling component of the scattering at the reference wavelength to the characteristic wavelength is quantified and subtracted. Then, the optical path baseline drift is corrected using the background intercept. The scattering ratio coefficient and background intercept need to be obtained through on-site calibration or online calibration methods to ensure they are updated according to changes in turbidity, water quality, etc. When obtaining the scattering ratio coefficient and background intercept through on-site calibration, first, after self-cleaning, pure water is flowed through a quartz flow cell, and absorbance at the reference wavelength of 700 nm and the characteristic wavelength of 254 nm is collected. The average of multiple measurements is used as the zero-point reference, and the intercept at this point is defined as the background intercept. Subsequently, a standard turbidity solution with a known turbidity value is injected, keeping the optical path fixed at 10 mm. Absorbance data for both wavelengths are collected simultaneously under different turbidity gradients. Since the standard turbidity solution at 254 nm... There is no characteristic chemical absorption at nm, and the difference in absorbance is entirely due to the scattering effect. By performing linear regression analysis on multiple sets of data points, a straight line is fitted with the absorbance at the reference wavelength as the independent variable and the absorbance at the characteristic wavelength as the dependent variable. The slope is the scattering ratio coefficient. The above calibration process is repeated every preset period or after self-cleaning is triggered, and the newly acquired scattering ratio coefficient and background intercept are updated to ensure real-time correction with changes in water turbidity and ensure the accuracy of net absorbance calculation. The preset period is set manually according to the engineering situation. The shorter the period, the more frequent the calibration update and the more accurate the measurement inversion.

[0027] Step 4: Invert the net absorbance based on the standard curve to generate the complex equivalent concentration; The standard curve was established as follows: a standard solution with a known gradient was prepared using a complexing agent. The representative complexing agent was ethylenediaminetetraacetic acid (EDTA), and the corresponding complex was copper EDTA complex. The absorbance response of each standard solution was collected using the same optical path based on dual-beam ultraviolet detection. A linear fit was performed with the concentration of the standard solution as the true value and the corresponding absorbance response as the dependent variable to construct the standard curve and quantify the mapping between net absorbance and complex concentration.

[0028] Standard curve calibration steps: Preparation of calibration samples: Prepare a set of standard complexing agent solutions covering the target working range. The concentration gradient should cover the actual concentration range. The optical path conditions of the calibration solutions should be consistent, and the optical path length should be the actual optical path length of the flow cell. Record environmental parameters such as temperature and turbidity. Data acquisition and processing: Obtain the net absorbance of the standard solutions at the characteristic wavelength and reference wavelength using dual-beam ultraviolet detection. Use the concentration and corresponding net absorbance of each set of standard solutions as a pair of observation points. Calibration fitting: Use linear regression fitting. The linear fitting formula is: ; in, The calibrated slope is used to reflect the light absorption capacity of a unit concentration of complex under a unit optical path length. To calibrate the intercept, used to correct the optical background of the flow cell; It is the optical path length; The standard solution concentration is used to obtain the calibration slope and calibration intercept.

[0029] The net absorbance measured on-site was used to invert the equivalent concentration of the complex using the fitted calibration slope and calibration intercept, thereby obtaining the equivalent concentration of the target complex. The net absorbance was inverted based on the standard curve, and the inversion formula used was as follows: ; in, The concentration of the complex equivalent is used to characterize the total equivalent of complexes to be oxidized in wastewater. Traditional methods often use single-band absorbance for quantification, which is easily affected by turbidity, baseline drift, etc. This method improves accuracy and stability by combining the net absorbance after dual-beam correction with the standard curve.

[0030] Step 5: Based on the data of complex equivalent concentration, wastewater flow rate, available chlorine mass concentration and temperature, perform correlation analysis to generate the dosing flow rate; The feedforward control formula with fusion thermodynamic correction is used to calculate the dosing flow rate. Correlation analysis is performed based on the complex equivalent concentration, wastewater flow rate, available chlorine mass concentration, and temperature data to generate the dosing flow rate. ; in, This refers to the dosage flow rate, used to control the operating speed / stroke opening of the metering pump. A larger value indicates a larger operating speed / stroke opening. This is a stoichiometric coefficient used to determine the number of moles of chlorine required to oxidize a unit complex. Different oxidants correspond to fixed baseline values, which can be adjusted based on actual on-site reaction conditions. This is the wastewater volumetric flow rate, used to calculate the treatment load per unit time. β is the effective chlorine mass concentration, used to reflect the true effective component content of the oxidant. β is the apparent temperature sensitivity coefficient, used to quantify the influence of temperature on the oxidation reaction rate. The on-site gradient temperature calibration method is adopted, and the calibration process is as follows: keep the on-site operating parameters constant, maintaining the complex equivalent concentration, wastewater volumetric flow rate, oxidant effective chlorine mass concentration, stoichiometric coefficient, and safety factor constant. Simultaneously regulate the temperature of the water sample and the wastewater temperature in the oxidation reaction tank through the temperature control equipment. Use the equipment's factory calibration room temperature as the calibration reference temperature, covering the lowest to highest operating temperature range. Set multiple sets of gradient test temperature points. After adjusting the temperature to a certain set of gradient temperatures, maintain the temperature until the water sample temperature and oxidation reaction state are completely stable. Record the current real-time temperature and simultaneously collect the actual dosing flow rate that can completely oxidize the complex in the wastewater at this temperature. Switch all gradient temperature points sequentially and repeat the operation to obtain the corresponding data. Obtain the apparent temperature sensitivity coefficient through linear regression fitting. This is for real-time temperature monitoring of on-site operating conditions. To calibrate the reference temperature, used to characterize the base temperature. As a safety factor, a dosing margin is introduced to the feedforward reference dosage to compensate for the underdosing risk caused by fluctuations in influent concentration and flow rate, optical inversion errors, and non-uniform mixing in the reaction zone.

[0031] This reflects the load of wastewater entering the treatment area; the higher the load, the more chemicals are required per unit time. This is the thermodynamic amplification and attenuation factor of temperature on the reaction rate. As temperature increases, 1 / T decreases. When β > 0, this value decreases, thus reducing the dosage flow rate; conversely, decreasing temperature increases the dosage flow rate. It characterizes the amplification effect of temperature on the reaction rate and is used for the safety factor. A redundancy margin is introduced into the feedforward baseline to prevent underdosing risks caused by measurement errors, prediction uncertainties, or fluctuations. In the initial stage, a conservative baseline safety factor is set to ensure that no significant underdosing occurs under common fluctuations. This is suitable for scenarios with extremely high safety requirements and small fluctuations. When the real-time complex equivalent concentration is less than 30% of the daily average, the wastewater flow fluctuation is less than 5%, and the baseline drift of the reference wavelength absorbance is no greater than 0.01 AU, the safety factor is the baseline safety factor. When the real-time complex equivalent concentration is higher than 80% of the daily average, the wastewater flow fluctuation is between 5% and 15%, and the baseline drift of the reference wavelength absorbance is greater than 0.01 AU but not exceeding 0.02 AU, the safety factor is 110% of the baseline value. When the real-time complex equivalent concentration exceeds 100% of the daily average, the wastewater flow fluctuation is greater than or equal to 15%, and the baseline drift of the reference wavelength absorbance is greater than 0.02 AU, the safety factor is 120% of the baseline value.

[0032] A redox potential safety threshold is set. When the detected redox potential exceeds the safety threshold, the dosing flow rate is attenuated and corrected, and the corrected dosing flow rate is limited to a preset upper dosing limit, which is based on the metering pump and the reagent storage tank. After the redox potential warning is triggered, the dosing flow rate is attenuated and corrected and constrained by the upper dosing limit to ensure that overdosing does not occur under abnormal conditions.

[0033] Compared with traditional single or static dosing strategies, this application has real-time, multi-variable coupled feedforward control capabilities, which can dynamically adjust the dosing according to the current load, reaction rate and temperature conditions, thereby improving the utilization rate of the reagents and the stability of the treatment.

[0034] Step 6: Add oxidant based on the dosing flow rate and perform sedimentation separation to obtain supernatant and sludge.

[0035] The pH of the wastewater is adjusted to between 9.0 and 10.5, flocculants are added to generate flocs, and solid-liquid separation is performed. The supernatant is transported to the subsequent biological treatment unit, and the sludge is dewatered and recycled.

[0036] Reference Figure 2 The present invention also discloses a treatment system for electroplating wastewater, used to perform a treatment method for electroplating wastewater, comprising: The pretreatment module is used to physically filter the electroplating wastewater to be treated and to collect clean samples. The detection module is used to introduce clean samples into a quartz flow cell for dual-beam ultraviolet detection and to collect raw absorbance data. The raw absorbance data includes characteristic wavelength absorbance and reference wavelength absorbance. The characteristic wavelength absorbance is used to reflect the mixed effect of chemical absorption and scattering, and the reference wavelength absorbance is used to reflect the scattering effect of suspended particles in the water. The signal processing module is used to perform dual-wavelength scattering correction on the raw absorbance data to generate net absorbance, which reflects the true absorption of the complex to the characteristic wavelength. The complex determination module is used to invert the net absorbance based on the standard curve to generate the equivalent concentration of the complex. The standard curve is established by selecting a complexing agent to prepare a standard solution with a known gradient, collecting the absorbance response of each standard solution based on the same optical path of dual-beam ultraviolet detection, and performing linear fitting with the concentration of the standard solution as the true value and the corresponding absorbance response as the dependent variable to construct and obtain the standard curve. The dosing control module is used to perform correlation analysis based on the equivalent concentration of the complex, wastewater flow rate, available chlorine mass concentration and temperature data, and generate the dosing flow rate. The sedimentation treatment module is used to add oxidant based on the dosing flow rate and perform sedimentation separation to obtain supernatant and sludge.

[0037] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0038] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0039] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0040] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for treating electroplating wastewater, characterized in that, The specific steps include: S1. Physically filter the electroplating wastewater to be treated and collect clean samples; S2. The clean sample is introduced into a quartz flow cell and subjected to dual-beam ultraviolet detection to collect raw absorbance data. The raw absorbance data includes characteristic wavelength absorbance and reference wavelength absorbance. The characteristic wavelength absorbance is used to reflect the mixed effect of chemical absorption and scattering, and the reference wavelength absorbance is used to reflect the scattering effect of suspended particles in the water. S3. Perform dual-wavelength scattering correction on the original absorbance data to generate net absorbance, which is used to reflect the true absorption of the complex at the characteristic wavelength. S4. Based on the standard curve, the net absorbance is inverted to generate the equivalent concentration of the complex. The standard curve is established in the following way: a standard solution with a known gradient is prepared by selecting a complexing agent, and the absorbance response of each standard solution is collected based on the same optical path of dual-beam ultraviolet detection. The standard curve is constructed by linear fitting with the concentration of the standard solution as the true value and the corresponding absorbance response as the dependent variable. S5. Based on the correlation analysis of the complex equivalent concentration, wastewater flow rate, available chlorine mass concentration and temperature data, generate the dosing flow rate; S6. Add oxidant based on the dosing flow rate and perform sedimentation separation to obtain supernatant and sludge; The raw absorbance data is subjected to dual-wavelength scattering correction to generate net absorbance. The formula used is: ； Absorbance at characteristic wavelength For characteristic wavelength, For the reference wavelength absorbance, For reference wavelength, The scattering ratio coefficient, Background intercept; A safe threshold for oxidation-reduction potential is set. When the oxidation-reduction potential is detected to be higher than the safe threshold, the dosage flow rate is attenuated and corrected, and the corrected dosage flow rate is limited to a preset upper limit value. The upper limit value is set based on the metering pump and the drug storage tank. The dual-beam ultraviolet detection is performed in a self-cleaning flow cell. When the absorbance of the reference wavelength drifts relative to the zero-point reference by more than a preset threshold, self-cleaning is triggered. The self-cleaning includes high-pressure gas backflushing and acidic solution circulation cleaning.

2. The method for treating electroplating wastewater according to claim 1, characterized in that: The physical filtration is used to filter fiber fragments and suspended particles in electroplating wastewater. The characteristic wavelength is 254nm and the reference wavelength is 700nm.

3. The method for treating electroplating wastewater according to claim 1, characterized in that: The linear fitting formula is as follows: ； in, The calibrated slope is used to reflect the light absorption capacity of a unit concentration of complex under a unit optical path length. To calibrate the intercept, used to correct the optical background of the flow cell; It is the optical path length; This represents the concentration of the standard solution.

4. The method for treating electroplating wastewater according to claim 3, characterized in that: The net absorbance is inverted based on the standard curve, and the inversion formula used is as follows: ； in, This is the equivalent concentration of the complex, used to characterize the total equivalent amount of complexes to be oxidized in the wastewater.

5. The method for treating electroplating wastewater according to claim 4, characterized in that: The feedforward control formula with fusion thermodynamic correction is used to calculate the dosing flow rate. Correlation analysis is performed based on the complex equivalent concentration, wastewater flow rate, available chlorine mass concentration, and temperature data to generate the dosing flow rate. ； in, The dosage flow rate is used to control the output frequency of the metering pump. These are stoichiometric coefficients, used to determine the number of moles of chlorine required to oxidize a single complex. This is the wastewater volumetric flow rate, used to calculate the treatment load per unit time. β is the effective chlorine mass concentration, used to reflect the true effective component content of the oxidant; β is the apparent temperature sensitivity coefficient, used to quantify the degree of influence of temperature on the oxidation reaction rate. This is for real-time temperature monitoring of on-site operating conditions. To calibrate the reference temperature, used to characterize the base temperature. As a safety factor, a dosing margin is introduced to the feedforward reference dosage to compensate for the underdosing risk caused by fluctuations in influent concentration and flow rate, optical inversion errors, and non-uniform mixing in the reaction zone.

6. The method for treating electroplating wastewater according to claim 1, characterized in that: The sedimentation separation includes: adjusting the pH of the wastewater to between 9.0 and 10.5, adding flocculant to generate flocs, and performing solid-liquid separation.

7. A treatment system for electroplating wastewater, used to perform the treatment method for electroplating wastewater according to claim 1, characterized in that, include: The pretreatment module is used to physically filter the electroplating wastewater to be treated and to collect clean samples. The detection module is used to introduce clean samples into a quartz flow cell for dual-beam ultraviolet detection and to collect raw absorbance data. The raw absorbance data includes characteristic wavelength absorbance and reference wavelength absorbance. The characteristic wavelength absorbance is used to reflect the mixed effect of chemical absorption and scattering, and the reference wavelength absorbance is used to reflect the scattering effect of suspended particles in the water. The signal processing module is used to perform dual-wavelength scattering correction on the raw absorbance data to generate net absorbance, which reflects the true absorption of the complex to the characteristic wavelength. The complex determination module is used to invert the net absorbance based on the standard curve to generate the complex equivalent concentration. The standard curve is established by selecting a complexing agent to prepare a standard solution with a known gradient, collecting the absorbance response of each standard solution based on the same optical path of dual-beam ultraviolet detection, and performing linear fitting with the concentration of the standard solution as the true value and the corresponding absorbance response as the dependent variable to construct and obtain the standard curve. The dosing control module is used to perform correlation analysis based on the equivalent concentration of the complex, wastewater flow rate, available chlorine mass concentration and temperature data, and generate the dosing flow rate. The sedimentation treatment module is used to add oxidant based on the dosing flow rate and perform sedimentation separation to obtain supernatant and sludge.

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