Efficient recycling and cyclic extraction device for inorganic salt in cotton dyeing residual liquid

Abstract

The utility model innovatively provides a high-efficiency recycling and cyclic extraction device for inorganic salt in cotton dyeing residual liquid and an operation process of the high-efficiency recycling and cyclic extraction device for the inorganic salt in the cotton dyeing residual liquid aiming at treatment of the cotton dyeing residual liquid. According to the device, residual liquid is concentrated through pretreatment, dye and inorganic salt are separated through a complexing extraction technology, and then residual dye and impurities are thoroughly removed through oil phase regeneration and ceramic membrane oil removal. The process not only realizes the efficient separation of the dye (the chroma removal rate exceeds 99.8%), but also ensures the recycling of the inorganic salt, and the inorganic salt can be directly recycled for cotton dyeing production, so that the waste of water resources and the inorganic salt is greatly reduced. The method has the innovation points that the method is efficient, environment-friendly, low in cost and simple and convenient to operate, a new scheme for recycling resources is provided for the cotton dyeing industry, and sustainable development of the industry is promoted. The research of the utility model is supported by a national key research and development plan (No.2023YFC3207003).

Description

Technical Field

[0001] This invention relates to the field of dyeing and printing wastewater treatment and dye and salt separation and recovery technology, specifically to a high-efficiency cotton dyeing residue inorganic salt recovery and recycling extraction device. Background Technology

[0002] As a key industry for my country's social progress, the textile sector plays an indispensable role in supporting national economic growth. However, the booming development of this industry is accompanied by a large amount of wastewater discharge from dyeing and printing. In the dyeing and printing sector, cotton dyeing residue accounts for about 35% of the industry's total wastewater discharge. Data shows that producing one ton of cotton textiles requires an average of 80 to 120 tons of water. After multiple processing stages, this water is transformed into dyeing wastewater containing high concentrations of organic pollutants. Reactive dyeing highlights environmental problems during the dyeing process. Reactive dyes are the core dyes in cotton dyeing, accounting for over 37% of all dye consumption. In the typical treatment process of reactive dyes, a large amount of inorganic minerals must be introduced to enhance their adsorption capacity. However, afterwards, as much as 30% to 50% of the dye is lost in the hydrolysis reaction, resulting in an inability to stably adhere to the material. Cotton dyeing residue is characterized by containing a large amount of hydrolyzed dye components and various inorganic salts.

[0003] Currently, the treatment process for cotton textile dyeing wastewater involves collecting wastewater from each process, performing preliminary treatment using standard wastewater treatment methods, and then further purifying it using reverse osmosis membrane technology. However, due to the high salt content in the wastewater, the treatment efficiency of the reverse osmosis membrane is limited, requiring frequent cleaning and replacement of membrane elements, which leads to low water production efficiency and increased treatment costs. Furthermore, even after reverse osmosis treatment, the concentrated solution still has a high salt content, making further effective treatment difficult.

[0004] The device described in this patent has a unique design that combines complexation extraction with oil phase regeneration technology to achieve efficient recovery of inorganic salts from cotton dyeing residue. This not only significantly reduces the cost of treating these waste liquids, but also brings significant economic and environmental benefits. Utility Model Content

[0005] The purpose of this invention is to overcome the limitations of existing technologies and provide a highly efficient inorganic salt recovery and recycling extraction device for cotton dyeing residue.

[0006] This application provides a high-efficiency inorganic salt recovery and recycling extraction device for cotton dyeing residue, which includes: a pretreatment device, a complexation extraction device, an oil phase regeneration device, a ceramic membrane oil removal device, and a recycled water tank, wherein:

[0007] The pretreatment device includes a purification device and a concentration device. The purification device uses a multi-stage membrane to pre-treat the cotton dyeing residue to remove particulate matter and suspended matter, thereby obtaining a decolorizing salt solution and a concentrated cotton dyeing residue. The volume of the concentrated cotton dyeing residue is no more than 10% of the total cotton dyeing residue.

[0008] The complexation extraction device, connected to the pretreatment device, is used to receive the concentrate, and to perform extraction by adjusting the pH and adding a complexation extractant to separate the inorganic salts from the dye, thereby obtaining the extracted oil phase and the extracted aqueous phase.

[0009] An oil phase regeneration device, connected to a complexation extraction device, is used to receive the extracted oil phase. By adjusting the pH of the extracted oil phase, back-extraction is performed to back-extract the dye in the extracted oil phase into the aqueous phase, resulting in a back-extracted oil phase and a back-extracted aqueous phase.

[0010] The resource utilization device is connected to the oil phase regeneration device and is used to receive the back-extracted aqueous phase for resource utilization.

[0011] The ceramic membrane oil removal device is connected to the complexation extraction device to receive the extraction aqueous phase. After oil removal by the ceramic membrane, the ceramic membrane permeate enters the recycled water tank, and the concentrated water enters the oil phase regeneration device.

[0012] The recycled water tank is connected to the pretreatment unit's permeate water and the ceramic membrane permeate water, and is used to receive the extraction and decolorization brine.

[0013] Optionally, the pretreatment device includes a dissolved air flotation device, an immersed microfiltration membrane, a column ultrafiltration membrane, and a nanofiltration membrane, used to remove suspended solids and particulate matter from the cotton dyeing residue, and to concentrate the cotton dyeing residue to obtain a concentrated residue with a concentration factor greater than 10.

[0014] Optionally, the complexation extraction apparatus includes an extraction mixing tower and an extraction centrifuge, for achieving thorough mixing and reaction of the complexation extractant and the concentrate.

[0015] Optionally, the oil phase regeneration device includes a back-extraction mixing tower and a back-extraction centrifuge for achieving thorough mixing of the alkaline aqueous solution and the extract and oil phase regeneration.

[0016] Optionally, the resource utilization device can utilize the recycled cotton dyeing residue for resource utilization, such as in the preparation of battery electrodes, turning the concentrated cotton dyeing residue into valuable industrial raw materials or products.

[0017] Optionally, the ceramic membrane oil removal device includes a hollow flat ceramic membrane and a circulation pump, used to achieve efficient oil removal and recycling of brine.

[0018] Optionally, the color of the cotton dyeing residue is >3000, and the inorganic salt concentration is >1.0%.

[0019] Optionally, the inorganic salt is one or a mixture of sodium sulfate, sodium chloride, and sodium carbonate.

[0020] Optionally, the complexation extraction and oil phase regeneration combination unit can remove more than 99.8% of oil contaminants.

[0021] The technical solution of this utility model is summarized as follows:

[0022] First, the cotton dyeing residue is pretreated using a pretreatment device (such as nanofiltration, electrodialysis, ion exchange, etc.) to concentrate it to more than 10 times the original residue concentration, resulting in the concentrated cotton dyeing residue. This concentrated residue (hereinafter referred to as the concentrate) is then introduced into a complexation extraction device, where an extractant (preferably a tertiary amine compound, such as trioctylamine or trioctyldecyl tertiary amine) is used for extraction, forming an extract (i.e., the extraction oil phase described above) and a raffinate (i.e., the extraction aqueous phase described above). The extract further enters an oil phase regeneration device, where it is back-extracted using an alkaline aqueous solution (20%-80% sodium hydroxide aqueous solution by mass), generating a back-extracted oil phase (i.e., the back-extracted oil phase described above) and a back-extracted aqueous phase. The cotton dye enters the back-extracted aqueous phase, achieving cotton dye separation. The back-extracted oil phase returns to the extraction device for reuse. The back-extracted aqueous phase enters a resource utilization device.

[0023] Although the extraction process absorbs a large amount of cotton dyeing dye, a small amount of dye still remains in the extraction aqueous phase. To address this issue, this application employs a ceramic membrane oil removal device for further oil removal, eliminating residual cotton dyeing dye and impurities. The brine treated by the ceramic membrane oil removal device (i.e., the ceramic membrane permeate described above) is introduced into a recycled water tank, where it can be reused in the cotton dyeing production line, achieving the recycling of inorganic salts. This application achieves dye-salt separation through the coupling of membrane separation and extraction-back-extraction devices, significantly reducing the waste rate of water resources and inorganic salts in traditional processes, thereby ensuring a highly efficient treatment process and a stable resource recovery rate.

[0024] The cotton dyeing residue used in this application has a color value >2000 and an inorganic salt content >2%.

[0025] The inorganic salt is at least one of sodium sulfate, sodium chloride, and sodium carbonate.

[0026] The decolorization treatment used in this application is resin decolorization or activated carbon decolorization.

[0027] This application provides a high-efficiency inorganic salt recovery and recycling extraction device for cotton dyeing waste liquor, which can achieve efficient separation of dyes with a color removal rate of over 99.8%. The brine produced by this device will not have any adverse effects on the original dyeing process, realizing the recycling of salt in the cotton dyeing process. Inorganic salts are almost not lost in the entire recovery process, reducing the impact of inorganic salts on the salinity of dyeing and printing wastewater. In addition, the device provided by this application generates almost no additional waste in the process of recovering cotton and its product dyeing waste liquor (i.e., cotton dyeing waste liquor). The extraction process can greatly reduce the treatment cost and improve the treatment efficiency of the concentrate. At the same time, the obtained inorganic salts can be directly reused in the cotton dyeing process. The regenerated cotton dyeing waste liquor (i.e., the liquid in the resource utilization device, i.e., the back-extraction aqueous phase) can be directly used to produce lithium battery electrode materials. Furthermore, the operating conditions of the high-efficiency inorganic salt recovery and recycling extraction device for cotton dyeing waste liquor provided by this application are easy to control, with high water recovery rate and inorganic salt reuse rate, and low treatment cost, providing a new solution for the treatment of cotton dyeing waste liquor. Attached Figure Description

[0028] Figure 1 This is a schematic block diagram of a highly efficient inorganic salt recovery and recycling extraction device for cotton dyeing residue. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments.

[0030] Example 1

[0031] An efficient inorganic salt recovery, extraction, and regeneration device for cotton dyeing residue includes the following steps: After pretreatment, the cotton dyeing residue (color 5980, sodium chloride content 3.12%) is fed into an extraction device and extracted with an extractant (trioctylamine) to obtain an extract and a raffinate solution. The extract is then passed into an oil phase regeneration device and back-extracted with an alkaline aqueous solution (50% sodium hydroxide solution) to obtain an oil phase and concentrated cotton dyeing residue. The oil phase is returned to the extraction device as an extractant (the oil phase can be reused as an extractant in the extraction device), and the concentrated cotton dyeing residue is collected. The raffinate solution is then passed into an extractant separation device, and after settling and separation, an extractant and a salt solution are obtained. The extractant is reused in the extraction device. At this point, the liquid has a color of 119.6 and a sodium chloride content of 8.4%. The back-extracted aqueous phase is ultimately utilized as a resource.

[0032] Example 2

[0033] An efficient inorganic salt recovery, extraction, and regeneration device for cotton dyeing residue includes the following steps: After pretreatment, the cotton dyeing residue (color 7530, sodium sulfate content 2.57%) is fed into an extraction device and extracted with an extractant (trioctyldecyl tertiary amine) to obtain an extract and a raffinate solution. The extract is then passed into an oil phase regeneration device and back-extracted with an alkaline aqueous solution (80% sodium hydroxide solution) to obtain an oil phase and concentrated cotton dyeing residue. The oil phase is returned to the extraction device as an extractant (the oil phase can be reused as an extractant in the extraction device), and the concentrated cotton dyeing residue is collected. The raffinate solution is then passed into an extractant separation device, and after settling and separation, an extractant and a salt solution are obtained. The extractant is reused in the extraction device; at this point, the liquid has a color of 153 and a sodium sulfate content of 5.9%. The back-extracted aqueous phase is ultimately utilized as a resource.

[0034] Example 3

[0035] An efficient inorganic salt recovery, extraction, and regeneration device for cotton dyeing residue includes the following steps: After pretreatment, the cotton dyeing residue (color 3880, sodium carbonate content 2.13%) is fed into an extraction device and extracted with an extractant (trioctylamine) to obtain an extract and a residual salt solution. The extract is then passed into an oil phase regeneration device and back-extracted with an alkaline aqueous solution (20% sodium hydroxide aqueous solution) to obtain an oil phase and concentrated cotton dyeing residue. The oil phase is returned to the extraction device as an extractant (the oil phase can be reused as an extractant in the extraction device), and the concentrated cotton dyeing residue is collected. The residual salt solution is then passed into an extractant separation device, and after settling and separation, an extractant and a salt solution are obtained. The extractant is reused in the extraction device. At this point, the liquid fed into the salt adjustment tank has a color of 78 and a sodium carbonate content of 11.3%. The back-extracted aqueous phase is ultimately utilized as a resource.

Claims

1. A high-efficiency inorganic salt recovery and recycling extraction device for cotton dyeing residue, characterized in that, include: The system includes a pretreatment unit, a complexation extraction unit, an oil phase regeneration unit, a resource utilization unit, a ceramic membrane oil removal unit, and a recycled water tank, wherein: The pretreatment device includes a purification device and a concentration device. The purification device uses a multi-stage membrane to pre-treat the cotton dyeing residue, removing particulate matter and suspended matter to obtain a decolorizing salt solution and a concentrated cotton dyeing residue. The volume of the concentrated cotton dyeing residue is no more than 10% of the total volume of the cotton dyeing residue. The complexation extraction device is connected to the pretreatment device and is used to receive the concentrated cotton dyeing residue. Extraction is carried out by adjusting the pH and adding a complexation extractant to separate the inorganic salts from the dye, and to obtain an extraction oil phase and an extraction aqueous phase. The oil phase regeneration device is connected to the complexation extraction device and is used to receive the extracted oil phase. By adjusting the pH of the extracted oil phase, back-extraction is performed to back-extract the dye in the extracted oil phase into the aqueous phase, resulting in a back-extracted oil phase and a back-extracted aqueous phase. The resource utilization device is connected to the oil phase regeneration device and is used to receive the back-extracted aqueous phase for resource utilization. The ceramic membrane oil removal device is connected to the complexation extraction device and is used to receive the extraction aqueous phase. After oil removal by the ceramic membrane, the ceramic membrane permeate enters the recycled water tank, and the concentrated water enters the oil phase regeneration device. The recycled water tank is connected to the pretreatment device to receive the decolorized brine, and is also connected to the ceramic membrane oil removal device to receive the ceramic membrane permeate.

2. The apparatus according to claim 1, characterized in that, The impurity removal device and the concentration device in the pretreatment device include a dissolved air flotation device, an immersed microfiltration membrane, a column ultrafiltration membrane, and a nanofiltration membrane, which are used to remove suspended solids and particulate matter from cotton dyeing residue, and at the same time concentrate the cotton dyeing residue to obtain a concentrated cotton dyeing residue with a concentration ratio of >10.

3. The apparatus according to claim 1, characterized in that, The complexation extraction device includes an extraction mixing tower and an extraction centrifuge, which are used to achieve thorough mixing and reaction of the complexation extractant and the concentrate.

4. The apparatus according to claim 1, characterized in that, The oil phase regeneration device includes a back-extraction mixing tower and a back-extraction centrifuge, used to achieve thorough mixing of the alkaline aqueous solution and the extract and regeneration of the oil phase.

5. The apparatus according to claim 1, characterized in that, The ceramic membrane oil removal device includes a ceramic membrane and a circulation pump, which is used to achieve efficient oil removal and recycling of brine. The ceramic membrane is a hollow flat ceramic membrane.

6. The apparatus according to claim 1, characterized in that, The residual cotton dye liquor has a color value >3000 and an inorganic salt concentration >1.0%.

7. The apparatus according to claim 6, characterized in that, The inorganic salt is one or a mixture of sodium sulfate, sodium chloride, and sodium carbonate.

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