Dye vat waste liquid treatment and utilization method and system

Abstract

The dye vat waste liquid treatment and utilization method comprises the following steps that waste water in a dye vat is conveyed to a connecting pipe set, dye liquor in the connecting pipe set is detected through a spectrophotometer, the conveyed dye liquor is distinguished to be light-color dye liquor or dark-color dye liquor through the spectrophotometer, if the dye liquor is the light-color dye liquor, the dye liquor is conveyed to a water storage tank, and if the dye liquor is the dark-color dye liquor, the dye liquor is conveyed to the water storage tank; if the dye liquor is dark dye liquor and sent to the waste water tank, the dye liquor in the water storage tank is subjected to color measurement recording through a spectrophotometer, the needed standard color is compared with the color of the dye liquor in the water storage tank, and the dye liquor closest to the dye liquor in the water storage tank is selected and sent to the water mixing tank to be mixed with the needed dye liquor. The light-color dye liquor with better water quality is independently recycled to the water storage tank for later use, water resource waste caused by mixed discharge of the light-color dye liquor and dark-color dye liquor is avoided, and practical application verifies that the wastewater recycling rate of the dye vat is improved, the fresh water consumption is remarkably reduced, the dye adding amount during preparation of new dye liquor can also be reduced, and the production raw material cost can be reduced.

Description

Technical Field

[0001] This invention relates to the field of dyeing and printing water treatment technology, and more specifically, to a method and system for treating and utilizing dyeing vat wastewater. Background Technology

[0002] In existing technologies, the textile printing and dyeing industry, as a high water-consuming industry, sees wastewater discharge from dyeing vats as a major source of water waste. Currently, the industry generally mixes and discharges wastewater from dyeing vats of different shades without targeted treatment or recycling. Dark-colored wastewater, due to its high dye concentration, requires a large amount of reagents for treatment, while light-colored wastewater has a lower concentration and has the potential for direct recycling. Mixing the two not only increases the overall treatment difficulty and cost but also leads to the waste of water resources in the light-colored wastewater. Direct discharge not only increases the cost per ton of water but also increases the load on the wastewater treatment system, which is inconsistent with current environmental protection policies and sustainable development requirements. Therefore, a technical solution is needed to address these issues. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art, enabling the differentiation between dark and light-colored wastewater, and allowing the light-colored wastewater to be reused, thereby providing a method and system for treating and utilizing dyeing vat wastewater.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention discloses a method for treating and utilizing dyeing vat wastewater, comprising the following steps:

[0006] S1. Send the wastewater in the dyeing vat to the connecting pipe assembly, and use a spectrophotometer to detect the dyeing solution in the connecting pipe assembly;

[0007] S2. The dispensing dye solution is distinguished as light-colored or dark-colored by a spectrophotometer. If the dye solution is light-colored, it is sent to the water storage tank; if the dye solution is dark-colored, it is sent to the wastewater tank.

[0008] S3. The color of the dye solution in the water tank is measured and recorded using a spectrophotometer;

[0009] S4. Compare the required standard color with the color of the dye solution in the water tank, and select the closest dye solution from the water tank to send to the mixing tank to prepare the required dye solution.

[0010] Furthermore, in step S1, a connecting pipe assembly is installed on the drain pipes of multiple dyeing vats, and multiple connecting pipe assemblies are arranged side by side. Each connecting pipe assembly includes a section of transparent pipe, and the spectrophotometer detects the transparent pipe accordingly.

[0011] Furthermore, the connecting pipe assembly includes a main pipe, two tee joints, and a detection pipe. The two tee joints are connected to both ends of the main pipe, and each tee joint includes a branch pipe. Both ends of the detection pipe are connected to the branch pipe, and the detection pipe is a transparent pipe.

[0012] Furthermore, the main pipe and the detection pipe are arranged in parallel, the branch pipe is arranged at an angle to the horizontal line, and the branch pipe is located below the main pipe.

[0013] Furthermore, in step S2, the brightness value L and full-spectrum transmittance T_avg data of the waste liquid in the connecting tube group are collected by a spectrophotometer. It is preset that when the brightness value L≥35 and the full-spectrum average transmittance T_avg≥45% are simultaneously satisfied, it is determined to be a light-colored dye liquid; when the brightness value L<35 or T_avg<45% are satisfied, it is determined to be a dark-colored dye liquid.

[0014] Furthermore, in step S2, the equation for calculating the brightness value L is:

[0015]

[0016] Where Y is the tristimulation value of the dye solution to be tested. The tristimulus values ​​of a perfectly reflective diffuser under standard conditions. .

[0017] Furthermore, in step S2, the equation for calculating the full-spectrum average transmittance T_avg is: the arithmetic mean of the transmittance data within the range of 380nm-780nm is:

[0018]

[0019] in, This represents the full-spectral transmittance of the dye solution at a specific wavelength. It is the differential of the wavelength.

[0020] Furthermore, in step S3, after the light-colored dye solution in the water tank is allowed to stand for 20-30 minutes to remove air bubbles, it is transported to the detection branch of the water tank by a circulation pump. The colorimeter with the same parameters as in S1 is used to measure the color again, and its complete CIE Lab parameters (L, a, b) and full-spectrum transmittance curve are recorded.

[0021] Furthermore, in step S4, the standard color parameters of the dye liquor required for production are compared with the dye liquor data in the storage tanks, and the color difference between the dye liquor in each storage tank and the standard color is calculated using the following color difference equation. :

[0022]

[0023] in, , , , , , Let be the color parameter of the dye solution in the i-th water tank. , , These are the standard color parameters for the dye solution required for production.

[0024] This invention also discloses a dyeing vat wastewater treatment and utilization system, including multiple dyeing vats, multiple connecting pipe assemblies, a transfer pump, multiple water storage tanks, a wastewater tank, a water conditioning tank, and a spectrophotometer. The outlet pipes of the dyeing vats are connected to the connecting pipe assemblies. The spectrophotometer can detect the dye liquid in the connecting pipe assemblies online. The connecting pipe assemblies are connected to the transfer pumps. The transfer pumps are connected to each water storage tank and the wastewater tank. Each water storage tank is equipped with a corresponding detection pool. The spectrophotometer can detect the dye liquid in the detection pool. The water storage tanks are connected to the water conditioning tank, which can be used to prepare the dye liquid required for production.

[0025] The beneficial effects of this invention are:

[0026] 1. This invention enables differentiated classification and recycling of dyeing vat wastewater, significantly improving water resource utilization. By using a spectrophotometer to accurately distinguish between light and dark dye liquors, the lighter dye liquor with better water quality is separately recycled to a storage tank for later use, avoiding water waste caused by mixing it with highly polluted dark dye liquor. Practical application has verified that this invention improves the reuse rate of dyeing vat wastewater and significantly reduces the consumption of fresh water.

[0027] 2. This invention utilizes light-colored dye liquor, which does not require complex deep treatment like dark-colored dye liquor. It can be directly recycled and reused after simple preparation, reducing the consumption of treatment agents. The reused light-colored dye liquor itself contains a certain amount of dye, which can reduce the amount of dye added when preparing new dye liquor and reduce the cost of raw materials for production. Attached Figure Description

[0028] Figure 1 This is a flowchart of one embodiment.

[0029] Figure 2 This is a system diagram of this embodiment.

[0030] Figure 3 This is a schematic diagram of a connecting pipe assembly in this embodiment.

[0031] Figure 4 This is a side view of the connecting pipe assembly in this embodiment.

[0032] Attached reference numerals: 1. Dyeing vat; 2. Connecting pipe assembly; 21. Main pipe; 22. Tee joint; 221. Branch pipe; 23. Detection pipe; 24. Elbow; 3. Transfer pump; 4. Water storage tank; 41. Detection pool; 5. Wastewater tank; 6. Water conditioning tank; 7. Spectrophotometer. Detailed Implementation

[0033] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figures 1-4 As shown in the figure, this embodiment discloses a method for treating and utilizing dyeing vat wastewater, including the following steps:

[0035] S1. Send the wastewater in dyeing vat 1 to connecting pipe assembly 2, and use spectrophotometer 7 to detect the dye solution in connecting pipe assembly 2;

[0036] Multiple dyeing vats 1 are installed in the production workshop. Electromagnetic valves are installed at the drain pipes of dyeing vats 1 to control the drainage of dyeing vats 1. Each drain pipe is connected to a connecting pipe assembly 2. The connecting pipe assembly 2 includes a transparent pipe. A spectrophotometer 7 is used to detect the dye liquor in the transparent pipe. Multiple connecting pipe assemblies 2 are arranged side by side. All dyeing vats 1 are connected to the connecting pipe assemblies 2 and arranged horizontally. The spectrophotometer 7 can move online to detect the dye liquor in different connecting pipe assemblies 2 through a device that can move horizontally and vertically.

[0037] Each connecting pipe assembly 2 includes a main pipe 21, two tee joints 22, and a detection pipe 23, which are fixedly connected to each other by flanges. The two tee joints 22 are connected to both ends of the main pipe 21. Each tee joint 22 includes a branch pipe 221. The two ends of the detection pipe 23 are connected to the branch pipe 221. The detection pipe 23 is a transparent pipe, made of quartz or high borosilicate glass. The two ends of the detection pipe 23 are connected to the two tee joints 22 by elbows 24. The main pipe 21 and the detection pipe 23 are arranged in parallel and horizontally. The branch pipe 221 is set at an angle to the horizontal line and is located below the main pipe 21. When the dyeing vat 1 is drained, the solenoid valve of the drain outlet of the dyeing vat 1 is opened, allowing the dye liquid in the dyeing vat 1 to enter the connecting pipe assembly 2. Because the detection pipe 23 is positioned low, when the dye liquid enters the connecting pipe assembly 2, it will fill the detection pipe 23 first, ensuring that there is no air interference in the detection of the detection pipe 23, making the detection more stable.

[0038] S2. The dispensing dye solution is distinguished as light-colored or dark-colored by the spectrophotometer 7. If the dye solution is light-colored, it is sent to the water storage tank 4. If the dye solution is dark-colored, it is sent to the wastewater tank 5.

[0039] The equation for calculating the brightness value L is:

[0040]

[0041] Where Y is the tristimulation value of the dye solution to be tested. The tristimulus values ​​of a perfectly reflective diffuser under standard conditions. .

[0042] The equation for calculating the full-spectrum average transmittance T_avg is: The transmittance data in the range of 380nm-780nm are arithmetically averaged, i.e.:

[0043]

[0044] in, This represents the full-spectral transmittance of the dye solution at a specific wavelength. It is the differential of the wavelength.

[0045] The spectrophotometer 7 collects the brightness value L and full-spectrum transmittance T_avg data of the waste liquid in the connecting pipe assembly. A light-colored dye solution is defined as one that simultaneously meets the criteria of brightness value L≥35 and full-spectrum average transmittance T_avg≥45%. A dark-colored dye solution is defined as one that meets the criteria of brightness value L<35 or T_avg<45%. Based on the determination results, the central control system controls the electromagnetic three-way valve at the outlet of the connecting pipe assembly 2 to switch the path: if it is a light-colored dye solution, it switches to the water storage tank 4 path, transporting it to the corresponding numbered water storage tank 4; if it is a dark-colored dye solution, it switches to the wastewater tank 5 path, transporting it to the wastewater tank 5 for subsequent deep processing.

[0046] S3. The color of the dye solution in the water storage tank 4 is measured and recorded by a spectrophotometer 7.

[0047] The water tank 4 has a built-in constant temperature stirring device. After the light-colored dye solution in the water tank 4 is allowed to stand for 25 minutes to remove residual air bubbles, it is transported to the detection branch of the water tank 4 by a circulation pump. The colorimeter 7 with the same parameters as S1 is used to measure the color again and record its complete CIE Lab parameters. , , The system displays the full-spectrum transmittance curve, where i is the serial number of the water tank 4. This allows for further confirmation of the color of the dye solution in the water tank 4, and these data are recorded into the color database of the central control system in sync with the dye solution storage time.

[0048] S4. Compare the required standard color with the color of the dye solution in the water storage tank 4, and select the closest dye solution from the water storage tank 4 to send to the water mixing tank 6 to prepare the required dye solution.

[0049] By comparing the standard color parameters of the dye liquor required for production with the dye liquor data in storage tank 4, the color difference between the dye liquor in each storage tank 4 and the standard color is calculated using the following color difference equation. :

[0050]

[0051] in, , , , , , Let be the color parameter of the dye solution in the i-th water tank 4. , , These are the standard color parameters for the dye solution required for production.

[0052] For example, in step S3, the water tank 4 is marked "L=42, a=15, b=20". The color difference between this marking and the standard color is obtained by substituting the parameters of the standard color into the formula. =1.2, this dye solution has the smallest color difference among all the water storage tanks 4. The dye solution in this water storage tank 4 is selected as the base mixing solution. It is delivered to the mixing tank 6 by a metering pump according to the preset ratio (dye solution: fresh water = 4:1). The mixing tank 6 has a built-in stirring device. A small amount of blue dye auxiliary agent is added according to the color difference value and then stirred and mixed. After mixing, the color parameters of the mixed dye solution are re-examined by a spectrophotometer 7. The color parameters of the mixed dye solution are L=45, a=12, b=22, and the color difference with the standard color is... =0.3, and the fluctuation of the result for three consecutive tests is ≤0.1, which is considered qualified and can be sent to dyeing vat 1 for subsequent dyeing production.

[0053] This embodiment can also detect dark-colored dye solutions, thereby achieving preliminary dyeing of a standard color by mixing dark-colored and light-colored dye solutions. The color parameters of the light-colored dye solution are preset as follows: , , The color parameters of the pretreated dark dye solution are ( , , The standard dye solution color parameters are ( , , The color parameters of the mixed dye solutions conform to the linear superposition law (based on the additivity characteristics of the CIE Lab color space). Let the mixing ratio of the light-colored dye solution be k (0 < k < 1), then the mixing ratio of the dark-colored dye solution is 1-k. Based on the principle of linear superposition of color parameters, the following system of equations is established:

[0054]

[0055] Because the actual color parameters of the dye solution may have slight deviations, the equations may not have an exact solution. In this case, the least squares method is used to find the optimal value of k, so that the color difference between the mixed dye solution and the standard color is minimized. Minimum, that is:

[0056]

[0057] Based on the calculated optimal ratio k, take the corresponding amounts of light-colored dye solution and dark-colored dye solution and mix them. Detect the color parameters of the mixed dye solution using a spectrophotometer, and add dyeing auxiliaries according to the detected color difference.

[0058] This embodiment also discloses a dyeing vat waste liquid treatment and utilization system, including multiple dyeing vats 1, multiple connecting pipe groups 2, a transfer pump 3, multiple water storage tanks 4, a wastewater tank 5, a water conditioning tank 6, and a spectrophotometer 7. The outlet pipe of the dyeing vat 1 is connected to the connecting pipe group 2. Each dyeing vat 1 has a solenoid valve installed in both its inlet and outlet pipes. The dye liquid from the dyeing vat 1 needs to undergo preliminary filtration before being discharged to the connecting pipe group 2. The solenoid valve of the outlet pipe is located between the dyeing vat 1 and the connecting pipe group 2. The spectrophotometer 7 can detect the dye liquid in the connecting pipe group 2 online. The connecting pipe group 2 is connected to the transfer pump 3. A solenoid valve is installed between the connecting pipe group 2 and the transfer pump 3. When the dyeing vat 1 drains water, the solenoid valve between the dyeing vat 1 and the connecting pipe group 2 opens, while the solenoid valve between the connecting pipe group 2 and the transfer pump 3 is closed. The dye liquid enters the connecting pipe group 2 and fills the detection tube 23 of the connecting pipe group. The spectrophotometer 7 moves and approaches the detection tube 23 for detection.

[0059] The transfer pump 3 is connected to each water storage tank 4 and wastewater tank 5. The transfer pump 3, water storage tank 4 and wastewater tank 5 are controlled by a three-way solenoid valve. If it is a light-colored dye solution, the flow is switched to the water storage tank 4 channel to deliver it to the corresponding numbered water storage tank 4. If it is a dark-colored dye solution, the flow is switched to the wastewater tank 5 channel to deliver it to the wastewater tank 5. Each water storage tank 4 is equipped with a solenoid valve in its inlet pipe. The color is determined and analyzed by a spectrophotometer 7 and compared with the existing dye solution color recorded in the water storage tank 4. If the color difference is less than 1, the dye solution is added to the corresponding water storage tank 4 and thoroughly stirred and mixed. Then, the color is detected and recorded by the spectrophotometer 7.

[0060] If the dye solution in each water tank 4 is not similar in color to the dye solution in the connecting pipe group 2, then the dye solution is added to an empty water tank 4. Each water tank 4 is equipped with a detection pool 41. The water tank 4 is equipped with a circulation pump, which can pass the dye solution in the water tank 4 through the detection pool 41. The spectrophotometer 7 can detect the dye solution in the detection pool 41.

[0061] Water storage tank 4 is connected to water mixing tank 6. Water mixing tank 6 can mix the dye liquor required for production. When the color of the dye liquor required for production is determined, it is compared with the color data in each water storage tank 4. The dye liquor in the water storage tank 4 with the smallest color difference is selected. The dye liquor is taken out by water pump and mixed with fresh water. After mixing, the color difference is determined by spectrophotometer 7. Dye auxiliaries are added according to the color difference value and stirred and mixed. The color difference is confirmed multiple times until the color difference is less than or equal to 0.1.

[0062] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for treating and utilizing dyeing vat wastewater, characterized in that, Includes the following steps: S1. Send the wastewater in the dyeing vat (1) to the connecting pipe assembly (2) and use a spectrophotometer (7) to detect the dyeing solution in the connecting pipe assembly (2); S2. The dispensing dye solution is distinguished as light-colored or dark-colored by a spectrophotometer (7). If the dye solution is light-colored, it is sent to the water storage tank (4). If the dye solution is dark-colored, it is sent to the wastewater tank (5). S3. The color of the dye solution in the water tank (4) is measured and recorded by a spectrophotometer (7); S4. Compare the required standard color with the color of the dye solution in the water tank (4), and select the closest dye solution in the water tank (4) to be sent to the water mixing tank (6) to prepare the required dye solution.

2. The method for treating and utilizing dyeing vat wastewater according to claim 1, characterized in that, In step S1, a connecting pipe group (2) is installed on the drain pipe of each of the multiple dyeing vats (1). The multiple connecting pipe groups (2) are arranged side by side. The connecting pipe group (2) includes a transparent pipe. The spectrophotometer (7) detects the transparent pipe.

3. The method for treating and utilizing dyeing vat wastewater according to claim 2, characterized in that, The connecting pipe assembly (2) includes a main pipe (21), two tee joints (22), and a detection pipe (23). The two tee joints (22) are connected to both ends of the main pipe (21). Each tee joint (22) includes a branch pipe (221). Both ends of the detection pipe (23) are connected to the branch pipe (221). The detection pipe (23) is a transparent pipe.

4. The method for treating and utilizing dyeing vat wastewater according to claim 3, characterized in that, The main pipe (21) and the detection pipe (23) are arranged in parallel, and the branch pipe (221) is arranged at an angle to the horizontal line. The branch pipe (221) is located below the main pipe (21).

5. The method for treating and utilizing dyeing vat wastewater according to claim 1, characterized in that, In step S2, the brightness value L and full-spectrum transmittance T_avg of the waste liquid in the connecting tube group are collected by a spectrophotometer. It is preset that when the brightness value L≥35 and the full-spectrum average transmittance T_avg≥45% are simultaneously satisfied, it is determined to be a light-colored dye liquid; when the brightness value L<35 or T_avg<45% are satisfied, it is determined to be a dark-colored dye liquid.

6. The method for treating and utilizing dyeing vat wastewater according to claim 5, characterized in that, In step S2, the equation for calculating the brightness value L is: Where Y is the tristimulation value of the dye solution to be tested. The tristimulus values ​​of a perfectly reflective diffuser under standard conditions. .

7. The method for treating and utilizing dyeing vat wastewater according to claim 5, characterized in that, In step S2, the equation for calculating the full-spectrum average transmittance T_avg is: The transmittance data in the range of 380nm-780nm are calculated using an arithmetic mean, i.e.: in, This represents the full-spectral transmittance of the dye solution at a specific wavelength. It is the differential of the wavelength.

8. The method for treating and utilizing dyeing vat wastewater according to claim 1, characterized in that, In step S3, after the light-colored dye solution in the water tank (4) is left to stand for 20-30 minutes to remove air bubbles, it is transported to the detection branch of the water tank (4) by a circulation pump. The colorimeter with the same parameters as in S1 is used to measure the color again and record its complete CIE Lab parameters and full-spectrum transmittance curve.

9. The method for treating and utilizing dyeing vat wastewater according to claim 1, characterized in that, In step S4, the standard color parameters of the dye liquor required for production are compared with the dye liquor data in the storage tank. The color difference between the dye liquor in each storage tank and the standard color is calculated using the following color difference equation. : in, , , , , , Let be the color parameter of the dye solution in the i-th water tank. , , These are the standard color parameters for the dye solution required for production.

10. A dyeing vat wastewater treatment and utilization system, used for carrying out the dyeing vat wastewater treatment and utilization method according to any one of claims 1-9, characterized in that, The system includes multiple dyeing vats (1), multiple connecting pipe assemblies (2), a transfer pump (3), multiple water storage tanks (4), a wastewater tank (5), a water conditioning tank (6), and a spectrophotometer (7). The outlet pipe of the dyeing vat (1) is connected to the connecting pipe assembly (2). The spectrophotometer (7) can detect the dye liquor in the connecting pipe assembly (2) online. The connecting pipe assembly (2) is connected to the transfer pump (3). The transfer pump (3) is connected to each water storage tank (4) and the wastewater tank (5). Each water storage tank (4) is equipped with a detection pool (41). The spectrophotometer (7) can detect the dye liquor in the detection pool (41). The water storage tank (4) is connected to the water conditioning tank (6). The water conditioning tank (6) can be used to prepare the dye liquor required for production.

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