Intelligent processing system and method for electroplating chromium-containing wastewater

Abstract

The application discloses an intelligent treatment system and method for electroplating chromium-containing wastewater, which comprises a sensor module, an image acquisition module, an intelligent control center and a controlled module; the sensor module is used for collecting operation data; the operation data comprises pH data and ORP data; the image acquisition module is used for collecting supernatant image data of a sedimentation tank; the controlled module is used for carrying out frequency conversion control of a dosing pump when adding chemicals to a chromium-breaking tank and / or when adding acid or alkali to a pH adjusting tank; and the intelligent control center is used for analyzing the received operation data and image data, and sending control signals to the controlled module to realize frequency conversion control of the controlled module. The application can accurately control the amount of reducing agent, thereby saving the amount of reducing agent and reducing the subsequent treatment load.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and specifically to an intelligent treatment system and method for chromium-containing wastewater from electroplating. Background Technology

[0002] The current treatment method for chromium-containing wastewater from electroplating generally involves a two-stage reduction-precipitation-filtration-deep treatment approach. The chromium-containing wastewater enters a primary pH adjustment tank after collection. Once the pH is adjusted to acidity, it continuously enters a two-stage chromium-breaking tank for reduction, converting highly toxic hexavalent chromium into less toxic trivalent chromium. After reduction, the wastewater passes through a secondary pH adjustment tank to adjust the pH to 7.5–8, causing the reduced trivalent chromium to precipitate as chromium hydroxide. This precipitate is then removed by a coagulation sedimentation tank. The resulting less toxic Cr(OH)3 precipitate is dehydrated, dried, and then utilized. The remaining chromium ions in the supernatant are filtered through an intermediate water tank and then undergo deep treatment before being discharged in compliance with standards.

[0003] In the above process, it is necessary to ensure that sufficient reducing agent is added to reduce hexavalent chromium to trivalent chromium (the content of hexavalent chromium should be ≤0.05mg / L). However, adding too much reducing agent will lead to poor precipitation of trivalent chromium, forming a stable colloid that is difficult to precipitate, increasing the total chromium content in the supernatant, and putting greater pressure on subsequent advanced treatment.

[0004] In summary, the current control method does not monitor the effluent from the coagulation sedimentation tank, and the method of controlling the dosing is also relatively crude. It relies on PLC automatic triggering control by monitoring the online ORP value of the two-stage chromium breaking tank within a certain range. This often leads to the problem of excessive dosage, resulting in poor sedimentation effect in the sedimentation tank, high color of the supernatant, high total chromium concentration, high load on subsequent processes, and excessive waste of chemicals.

[0005] Therefore, to solve the above problems, a new intelligent treatment system and method for chromium-containing electroplating wastewater is needed, which can accurately control the dosage of reducing agent, thereby saving the dosage of reducing agent and reducing the load on subsequent treatment. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to overcome the defects in the prior art and provide an intelligent treatment system and method for electroplating chromium-containing wastewater, which can accurately control the dosage of reducing agent, thereby saving the dosage of reducing agent and reducing the load on subsequent treatment.

[0007] The intelligent treatment system for chromium-containing electroplating wastewater of the present invention includes a sensor module, an image acquisition module, an intelligent control center, and a module to be controlled.

[0008] The sensor module is used to collect operational data, including pH data and ORP data.

[0009] The image acquisition module is used to acquire image data of the supernatant in the sedimentation tank;

[0010] The module to be controlled is used to perform frequency conversion control of the dosing pump when adding chemicals to the chromium breaking tank and / or adding acid or alkali to the pH adjustment tank;

[0011] The intelligent control center is used to analyze the received operating data and image data, and send control signals to the controlled module to realize the frequency conversion control of the controlled module.

[0012] Furthermore, the image acquisition module includes an underwater industrial camera, an augmenting light source, and a photoelectric signal transmission module;

[0013] The underwater industrial camera is installed at the top of the sedimentation tank to collect image data of the supernatant in the sedimentation tank. The image signal is transmitted to the intelligent control center through a photoelectric signal transmission module.

[0014] Furthermore, the sensor module includes a first pH sensor disposed in the primary pH adjustment tank, a second pH sensor disposed in the secondary pH adjustment tank, a first ORP sensor disposed in the primary pH adjustment tank, a second ORP sensor disposed in the primary chromium removal tank, and a third ORP sensor disposed in the secondary chromium removal tank.

[0015] Furthermore, the controllable module includes a first dosing pump frequency converter installed in the primary chromium breaking tank, a second dosing pump frequency converter installed in the secondary chromium breaking tank, a first acid-base dosing pump frequency converter installed in the primary pH adjustment tank, and a second acid-base dosing pump frequency converter installed in the secondary pH adjustment tank.

[0016] A smart treatment method for chromium-containing electroplating wastewater, utilizing a smart treatment system for chromium-containing electroplating wastewater, includes the following steps:

[0017] S1. Using total chromium concentration and hexavalent chromium concentration as target values, and three-stage ORP data and two-stage reducing agent dosage as inputs, a prediction model is constructed to predict whether the total chromium concentration and hexavalent chromium concentration in the supernatant of the sedimentation tank meet the standards under changes in ORP data and reducing agent dosage.

[0018] S2. Input the real-time collected three-stage ORP data and the dosage of the two-stage reducing agent into the prediction model. Take the group that predicts the lowest total dosage of hexavalent chromium concentration and the lowest dosage in the prediction model as the optimal dosage group. Adjust the dosage of the two-stage reducing agent so that the total dosage is equal to the total dosage in the optimal dosage group.

[0019] S3. Collect image data of the supernatant in the sedimentation tank. Determine whether the water in the sedimentation tank is turbid based on the image data. If so, the dosage of the drug predicted by the prediction model is inappropriate. Return to step S2 until the image data shows that the supernatant in the sedimentation tank is clear. If not, wait to enter the next prediction interval.

[0020] Furthermore, it also includes: step a. Before step S1, adjusting the pH value of the two-stage pH adjustment tanks, specifically including:

[0021] The pH adjustment range for the primary pH adjustment tank is set to 2.8–3.1, and the pH adjustment range for the secondary pH adjustment tank is set to 7.5–8.5.

[0022] Furthermore, feedback adjustments are made every t minutes. When the pH value of the water does not reach the set range, the frequency of the acid-base dosing pump is adjusted down or up by one frequency until the pH value reaches the set range.

[0023] Furthermore, the hexavalent chromium concentration in the target value is encoded in one-hot format.

[0024] Furthermore, the concentration of hexavalent chromium and the total chromium concentration were determined by titration and atomic absorption spectrometry, respectively.

[0025] Furthermore, the determination of whether the water in the sedimentation tank is turbid based on image data includes:

[0026] Convert the image to grayscale to obtain a grayscale image;

[0027] Edge enhancement processing is performed on the grayscale image, the variance value of the Laplacian operator filter is calculated, a fast Fourier transform is performed on the grayscale image, and the average value of the fast Fourier transform amplitude is calculated.

[0028] If the variance of the Laplace operator filter and the average amplitude of the fast Fourier transform do not exceed their respective set thresholds, the water in the sedimentation tank is determined to be blurry; otherwise, the water in the sedimentation tank is considered clear.

[0029] The beneficial effects of this invention are as follows: The intelligent treatment system and method for chromium-containing electroplating wastewater disclosed in this invention achieves optimized control of the chemical reduction precipitation treatment process of electroplating wastewater by establishing a predictive model and image feedback control. It accurately controls the dosage of reducing agent, resulting in good sedimentation effect in the coagulation sedimentation tank, clearer supernatant with lower color and lower total chromium content. This reduces the load on subsequent filtration and deep treatment processes, extends the backwashing time of the filter and the regeneration time of the ion exchange resin, thereby reducing consumption and saving the dosage of reducing agent. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0031] Figure 1 This is a schematic diagram of the layout structure of the intelligent processing system of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings, as shown in the figures:

[0033] The intelligent treatment system for chromium-containing electroplating wastewater of the present invention includes: a sensor module, an image acquisition module, an intelligent control center, and a module to be controlled;

[0034] The sensor module is used to collect operational data, including pH data and ORP data.

[0035] The image acquisition module is used to acquire image data of the supernatant in the sedimentation tank;

[0036] The module to be controlled is used to perform frequency conversion control of the dosing pump when adding chemicals to the chromium breaking tank and / or adding acid or alkali to the pH adjustment tank;

[0037] The intelligent control center analyzes the received operational and image data and sends control signals to the controlled modules to achieve frequency conversion control of the controlled modules. The intelligent control center includes a local storage device, a server, and a display screen. The local storage device is used to establish a data platform and form a historical database.

[0038] In this embodiment, the image acquisition module includes an underwater industrial camera, an augmenting light source, and a photoelectric signal transmission module; the image acquisition module is... Figure 1 The image acquisition device shown is used in underwater environments where light gradually diminishes, and deep water areas can be extremely dark. An augmented light source provides additional illumination to enhance the camera's visual capabilities, enabling it to acquire clearer images of the sedimentation tank under low-light conditions.

[0039] The underwater industrial camera is installed at the top of the sedimentation tank to collect image data of the supernatant in the sedimentation tank. The image signal is transmitted to the intelligent control center through a photoelectric signal transmission module.

[0040] In this embodiment, the sensor module includes a first pH sensor disposed in the primary pH adjustment tank, a second pH sensor disposed in the secondary pH adjustment tank, a first ORP sensor disposed in the primary pH adjustment tank, a second ORP sensor disposed in the primary chromium removal tank, and a third ORP sensor disposed in the secondary chromium removal tank. The ORP sensor (oxidation-reduction potential sensor) is a sensor used to measure the oxidation-reduction potential in a liquid; the potential change measured by the ORP sensor reflects the intensity of the oxidation-reduction reaction in the liquid.

[0041] With the above setup, pH sensor data from the two-stage pH adjustment tanks and ORP sensor data from the adjustment tanks and two-stage reduction tanks can be collected, providing a data foundation for subsequent data utilization and analysis.

[0042] In this embodiment, the controllable module includes a first dosing pump frequency converter located in the primary chromium breaking tank, a second dosing pump frequency converter located in the secondary chromium breaking tank, a first acid-base dosing pump frequency converter located in the primary pH adjustment tank, and a second acid-base dosing pump frequency converter located in the secondary pH adjustment tank. The dosing pump frequency converters and the acid-base dosing pump frequency converters both utilize existing pump frequency conversion control equipment, which will not be described in detail here.

[0043] The above settings enable efficient and effective adjustment of the pH value in the pH adjustment tank and the dosage of the reducing agent.

[0044] This invention also relates to an intelligent treatment method for chromium-containing electroplating wastewater. The method utilizes the intelligent treatment system for chromium-containing electroplating wastewater described in the above embodiments and includes the following steps:

[0045] S1. Using total chromium concentration and hexavalent chromium concentration as target values, and three-stage ORP data and two-stage reducing agent dosage as inputs, a predictive model is constructed to predict whether the total chromium concentration and hexavalent chromium concentration in the supernatant of the sedimentation tank will meet the standards under changes in ORP data and reducing agent dosage. The predictive model can use an existing neural network model, such as an LSTM model. The two-stage reducing agent dosages are the reducing agent dosages for the first-stage chromium breaking tank and the second-stage chromium breaking tank, respectively.

[0046] S2. Input the real-time collected three-stage ORP data and the dosage of the two-stage reducing agent into the prediction model. Take the group that predicts the lowest total dosage of hexavalent chromium concentration and the lowest dosage in the prediction model as the optimal dosage group. Adjust the dosage of the two-stage reducing agent so that the total dosage is equal to the total dosage in the optimal dosage group.

[0047] S3. Collect image data of the supernatant in the sedimentation tank. Based on the image data, determine whether the water in the sedimentation tank is turbid. If so, the dosage of the chemical predicted by the prediction model is inappropriate, and return to step S2 until the image data indicates that the supernatant in the sedimentation tank is clear. If not, wait to enter the next prediction interval. This forms an intelligent control system for real-time monitoring, optimization, and adjustment.

[0048] In this embodiment, the processing method further includes: step a. Before step S1, adjusting the pH value of the two-stage pH adjustment tanks, specifically including:

[0049] The primary pH adjustment tank is set with a pH range of 2.8–3.1, and the secondary pH adjustment tank is set with a pH range of 7.5–8.5. By adjusting the pH value, the chemical form of hexavalent chromium in the wastewater can be altered, thereby optimizing its solubility and toxicity.

[0050] In this embodiment, feedback adjustment is performed every 10 minutes. When the pH value of the water does not reach the set range, the frequency of the acid-base dosing pump is adjusted down or up by one frequency until the pH value reaches the set range.

[0051] In this embodiment, the hexavalent chromium concentration in the target value is represented using one-hot encoding. Specifically, the hexavalent chromium concentration is compared with the target value (0.05 mg / L), and the hexavalent chromium concentration is represented using one-hot encoding. One-hot encoding converts discrete data into a format that is better understood or recognized by neural network models.

[0052] In this embodiment, titration and atomic absorption spectrometry were used to determine the concentrations of hexavalent chromium and total chromium, respectively. Specifically, a sample of the supernatant from the sedimentation tank was manually collected, and then titration and atomic absorption spectrometry were used to determine the concentrations of hexavalent chromium and total chromium, respectively.

[0053] Titration can be performed under relatively simple laboratory conditions without requiring complex instruments and equipment. Atomic absorption spectrometry, on the other hand, typically offers high selectivity, enabling accurate determination of target elements in complex samples with reduced interference.

[0054] In this embodiment, determining whether the water in the sedimentation tank is turbid based on image data specifically includes:

[0055] An image is converted to grayscale to obtain a grayscale image. The original image may be in color. Grayscale conversion is the process of converting a color image into a grayscale image. A grayscale image is a single-channel image, and the value of each pixel represents its grayscale level. Grayscale conversion simplifies processing and reduces computational complexity.

[0056] Edge enhancement processing is performed on grayscale images by calculating the variance of the Laplacian operator filter. By applying the Laplacian operator to a grayscale image, high-frequency details can be highlighted. The variance of the image after Laplacian filtering represents the degree of grayscale variation in the image; a higher variance generally indicates a sharper image.

[0057] Perform a Fast Fourier Transform (FFT) on a grayscale image and calculate the average amplitude of the FFT. Calculate the amplitude spectrum of the image after the FFT and then calculate the average amplitude. This can be used to analyze the image's characteristics in the frequency domain and understand the main frequency components. A higher average amplitude value indicates a clearer image.

[0058] If the variance of the Laplace operator filter and the average amplitude of the Fast Fourier Transform do not exceed their respective set thresholds, the water in the sedimentation tank is considered blurry; otherwise, the water in the sedimentation tank is considered clear. These thresholds can be set based on work experience or specific application conditions.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A smart treatment method for chromium-containing electroplating wastewater, characterized in that: A smart treatment system for chromium-containing wastewater from electroplating; The intelligent treatment system for chromium-containing electroplating wastewater includes a sensor module, an image acquisition module, an intelligent control center, and a controllable module. The sensor module is used to collect operational data, including pH data and ORP data. The image acquisition module is used to acquire image data of the supernatant in the sedimentation tank; The module to be controlled is used to perform frequency conversion control of the dosing pump when adding chemicals to the chromium breaking tank and / or adding acid or alkali to the pH adjustment tank; The intelligent control center is used to analyze the received operating data and image data, and send control signals to the controlled module to realize the frequency conversion control of the controlled module; The sensor module includes a first pH sensor installed in the primary pH adjustment tank, a second pH sensor installed in the secondary pH adjustment tank, a first ORP sensor installed in the primary pH adjustment tank, a second ORP sensor installed in the primary chromium removal tank, and a third ORP sensor installed in the secondary chromium removal tank. The controllable module includes a first dosing pump frequency converter installed in the primary chromium breaking tank, a second dosing pump frequency converter installed in the secondary chromium breaking tank, a first acid-base dosing pump frequency converter installed in the primary pH adjustment tank, and a second acid-base dosing pump frequency converter installed in the secondary pH adjustment tank. The intelligent treatment method for chromium-containing electroplating wastewater includes the following steps: S1. Using total chromium concentration and hexavalent chromium concentration as target values, and three-stage ORP data and two-stage reducing agent dosage as inputs, a prediction model is constructed to predict whether the total chromium concentration and hexavalent chromium concentration in the supernatant of the sedimentation tank meet the standards under changes in ORP data and reducing agent dosage. S2. Input the real-time collected three-stage ORP data and the dosage of the two-stage reducing agent into the prediction model. Take the group that predicts the lowest total dosage of hexavalent chromium concentration and the lowest dosage in the prediction model as the optimal dosage group. Adjust the dosage of the two-stage reducing agent so that the total dosage is equal to the total dosage in the optimal dosage group. S3. Collect image data of the supernatant in the sedimentation tank. Determine whether the water in the sedimentation tank is turbid based on the image data. If so, the dosage of the drug predicted by the prediction model is inappropriate. Return to step S2 until the image data shows that the supernatant in the sedimentation tank is clear. If not, wait to enter the next prediction interval.

2. The intelligent treatment method for chromium-containing electroplating wastewater according to claim 1, characterized in that: The image acquisition module includes an underwater industrial camera, an augmenting light source, and a photoelectric signal transmission module; The underwater industrial camera is installed at the top of the sedimentation tank to collect image data of the supernatant in the sedimentation tank. The image signal is transmitted to the intelligent control center through a photoelectric signal transmission module.

3. The intelligent treatment method for chromium-containing electroplating wastewater according to claim 1, characterized in that: Also includes: Step a. Before step S1, adjust the pH value of the two-stage pH adjustment tanks, specifically including: The pH adjustment range for the primary pH adjustment tank is set to 2.8–3.1, and the pH adjustment range for the secondary pH adjustment tank is set to 7.5–8.

5.

4. The intelligent treatment method for chromium-containing electroplating wastewater according to claim 3, characterized in that: Every The system provides feedback and adjustments every few minutes. When the pH value of the water does not reach the set range, the frequency of the acid-base dosing pump is adjusted down or up by one frequency until the pH value reaches the set range.

5. The intelligent treatment method for chromium-containing electroplating wastewater according to claim 1, characterized in that: The hexavalent chromium concentration in the target value is encoded in one-hot format.

6. The intelligent treatment method for chromium-containing electroplating wastewater according to claim 1, characterized in that: The concentrations of hexavalent chromium and total chromium were determined by titration and atomic absorption spectrometry, respectively.

7. The intelligent treatment method for chromium-containing electroplating wastewater according to claim 1, characterized in that: Determining whether the water in the sedimentation tank is turbid based on image data specifically includes: Convert the image to grayscale to obtain a grayscale image; Edge enhancement processing is performed on the grayscale image, the variance value of the Laplacian operator filter is calculated, a fast Fourier transform is performed on the grayscale image, and the average value of the fast Fourier transform amplitude is calculated. If the variance of the Laplace operator filter and the average amplitude of the fast Fourier transform do not exceed their respective set thresholds, the water in the sedimentation tank is determined to be turbid; otherwise, the water in the sedimentation tank is considered clear.

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