Reverse osmosis (RO) concentrated water resource utilization system for printing and dyeing wastewater

Abstract

The utility model relates to the field of printing and dyeing wastewater treatment equipment, in particular to a printing and dyeing wastewater RO (Reverse Osmosis) concentrated water resource utilization system. The utility model relates to a printing and dyeing wastewater RO concentrated water resource utilization system which comprises a first RO device, a first roll type ultrafiltration device, a first ozone oxidation device, a second roll type ultrafiltration device, a second ozone oxidation device, a second ozone oxidation device water producing pool, a nanofiltration device, a nanofiltration water producing pool and a resin device which are sequentially arranged.

Description

Technical Field

[0001] The utility model relates to the field of printing and dyeing wastewater treatment equipment, and particularly relates to a system for recycling RO concentrated water of printing and dyeing wastewater. Background Art

[0002] In the industry, in order to meet the need of water reuse, the membrane method is often used for the advanced treatment of printing and dyeing wastewater. After the printing and dyeing wastewater is pretreated and biologically treated, the first-stage membrane process treatment is carried out by using the UF or MBR process, and finally the RO membrane is used for advanced treatment. The RO-produced water is directly recycled, and the concentrated water is directly discharged to the next-level sewage treatment plant after simple treatment to meet the standards. At present, this set of process has been mature, but the water recovery rate can no longer keep up with the internal water use demand of enterprises. At the same time, according to the characteristics of printing and dyeing wastewater, the RO concentrated water contains a large amount of inorganic salts. Direct discharge causes waste of inorganic salt resources, and the high salt concentration of the wastewater also increases the biochemical burden of the backend sewage treatment plant. The RO concentrated water of printing and dyeing wastewater has the characteristics of high concentration multiple, high salt content, high organic matter concentration, high chroma, low BOD / COD, etc. Conventional biochemical and physical-chemical methods cannot effectively treat the RO concentrated water, so a suitable process system needs to be selected to treat it. At present, the treatment methods for RO concentrated water in the industry are not yet mature, and the resource recycling of inorganic salts in RO concentrated water is still in the development stage. Therefore, a resource utilization system for RO concentrated water of printing and dyeing wastewater is designed, which can improve the water reuse rate while treating the wastewater and bring many benefits.

[0003] The conventional treatment scheme for RO concentrated water of printing and dyeing wastewater generally adopts the process of "multi-stage membrane concentration + MVR evaporation". The operation energy consumption of the process is huge, and the purity of the recycled solid salt cannot be guaranteed; the existing salt recycling process for RO concentrated water of printing and dyeing wastewater generally only recovers sodium sulfate with a relatively high concentration. To ensure the purity of sodium sulfate, carbonate ions are generally removed by stripping, resulting in waste of more valuable sodium carbonate salt.

[0004] The existing patent CN115448477A proposes a method for advanced treatment and reclamation of intermediate water from printing and dyeing wastewater. The printing and dyeing wastewater is pretreated by sand filtration and fine filtration, and then ultrafiltration, adsorption and first-stage reverse osmosis treatment are carried out. The first-stage reverse osmosis concentrated water is subjected to second-stage reverse osmosis treatment. The produced water is collected for reclamation as intermediate water, and the RO concentrated water is further subjected to advanced treatment to remove organic impurities and then evaporation treatment. Although this method uses the RO process to greatly improve the water reuse rate, the treatment of RO concentrated water is not clear, and the final recycled salt process is not clear. No special separation and impurity removal are carried out on the recycled salt, and it is difficult to guarantee the purity of the recycled salt. Summary of the Invention

[0005] The utility model hopes to provide a system for recycling RO concentrated water of printing and dyeing wastewater, and the specific scheme is as follows:

[0006] A system for the resource utilization of RO concentrate from printing and dyeing wastewater, comprising a first RO device, a first spiral ultrafiltration device, a first ozone oxidation device, a second spiral ultrafiltration device, a second ozone oxidation device, a production water tank of the second ozone oxidation device, a nanofiltration device, a nanofiltration production water tank and a resin device, which are arranged in sequence.

[0007] The first RO device is connected to a production water tank of the first RO device.

[0008] The resin device is connected to a second RO device.

[0009] The nanofiltration device is connected to a third RO device.

[0010] The second RO device is connected to a concentrated water tank of the second RO device, and the third RO device is connected to a concentrated water tank of the third RO device.

[0011] The second RO device and the third RO device are commonly connected to a production water tank of the RO device.

[0012] The second spiral ultrafiltration device is connected to an evaporation device, and the evaporation device is connected to a solid waste storage device.

[0013] The utility model has the following advantages:

[0014] 1. Aiming at the characteristics of high pollution and high salt content of RO concentrate from printing and dyeing wastewater, a set of resource utilization system is designed, which avoids the waste of inorganic salt resources and water resources in the wastewater, reduces the biochemical treatment burden caused by direct discharge to the lower-level sewage treatment plant, and reduces the environmental pollution risk;

[0015] 2. The system for the resource utilization of RO concentrate from printing and dyeing wastewater can separate sodium sulfate and sodium carbonate and recycle them respectively, avoiding the waste of sodium carbonate and improving the economic benefits of the printing and dyeing factory;

[0016] 3. Both sodium carbonate and sodium sulfate are recycled in the form of solutions, avoiding the huge energy consumption required by the solid recycling evaporation process and reducing the operation cost of the process;

[0017] 4. The system adopts two-stage spiral ultrafiltration devices and cooperates with the MVR device to evaporate the small amount of concentrated water after spiral ultrafiltration, greatly improving the recycling rates of water and salt and realizing the zero-discharge treatment of RO concentrate;

[0018] 5. By treating the RO concentrate of printing and dyeing wastewater with this system, the problem of high pollution of RO concentrate is solved, the reuse of wastewater resources is realized, and at the same time, the integration of devices in each stage makes the wastewater treatment system operate stably and efficiently. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of a system for the resource utilization of RO concentrate from printing and dyeing wastewater of the utility model;

[0020] Among them, the labels are as follows: 1. First RO device; 2. Product water tank of the first RO device; 3. First spiral ultrafiltration device; 4. First ozone oxidation device; 5. Second spiral ultrafiltration device; 6. Second ozone oxidation device; 7. Product water tank of the second ozone oxidation device; 8. Nanofiltration device; 9. Product water tank of nanofiltration; 10. Resin device; 11. Second RO device; 12. Concentrate water tank of the second RO device; 13. Third RO device; 14. Concentrate water tank of the third RO device; 15. Product water tank of the RO device; 16. Evaporation device; 17. Solid waste storage device. Specific embodiments

[0021] The following will be further described in conjunction with Figure 1 for further illustration:

[0022] A system for recycling RO concentrate resources of printing and dyeing wastewater includes a first RO device 1, a first spiral ultrafiltration device 3, a first ozone oxidation device 4, a second spiral ultrafiltration device 5, a second ozone oxidation device 6, a product water tank 7 of the second ozone oxidation device, a nanofiltration device 8, a product water tank 9 of nanofiltration, and a resin device 10 arranged in sequence.

[0023] The first RO device 1 is connected to a product water tank 2 of the first RO device.

[0024] The resin device 10 is connected to a second RO device 11, and the nanofiltration device 8 is connected to a third RO device 13.

[0025] The second RO device 11 is connected to a concentrate water tank 12 of the second RO device, and the third RO device 13 is connected to a concentrate water tank 14 of the third RO device.

[0026] The second RO device 11 and the third RO device 13 are commonly connected to a product water tank 15 of the RO device.

[0027] The second spiral ultrafiltration device 5 is connected to an evaporation device 16, and the evaporation device 16 is connected to a solid waste storage device 17.

[0028] The present invention proposes a system for recycling RO concentrate resources of printing and dyeing wastewater, which is designed based on the RO concentrate of the conventional membrane method for advanced treatment of printing and dyeing wastewater. The RO concentrate is rich in a large amount of inorganic salt resources. By combining devices such as spiral ultrafiltration, ozone oxidation, nanofiltration, resin, and reverse osmosis, the effective separation and separate reuse of sodium carbonate inorganic salt and sodium sulfate inorganic salt in the RO concentrate of printing and dyeing wastewater can be realized, and the wastewater resource utilization and zero discharge can be achieved.

[0029] See Figure 1 , a schematic diagram of the system for recycling RO concentrate resources of printing and dyeing wastewater.

[0030] Step 1: The pretreated printing and dyeing wastewater enters the first RO device 1, which is the last step in the advanced treatment stage of conventional printing and dyeing wastewater. The water produced after passing through the first RO system 1 enters the product water tank 2 of the first RO device for storage and reuse, and the concentrated water flows into the first spiral ultrafiltration device 3.

[0031] Step 2: The concentrated water end of the first RO device 1 is connected to the first spiral ultrafiltration device 3. After being treated by the first spiral ultrafiltration device 3, the organic matter and color in the produced water are significantly reduced, and the inorganic salt concentration is only slightly reduced, with a water production rate of 80%; after being treated by the first spiral ultrafiltration device 3, the pollutants and inorganic salt concentration in the concentrated water are concentrated, with a concentrated water rate of 20%.

[0032] Step 3: The concentrated water end of the first spiral ultrafiltration device 3 is connected to the first ozone oxidation device 4. After being treated by the first ozone oxidation device 4, the organic matter and color in the produced water are significantly removed.

[0033] Step 4: The product water end of the first ozone oxidation device 4 is connected to the second spiral ultrafiltration device 5. After being treated by the second spiral ultrafiltration device 5, the organic matter and color in the produced water are significantly reduced, and the inorganic salt concentration is only slightly reduced, with a water production rate of 80%; after being treated by the second spiral ultrafiltration device 5, the pollutants and inorganic salt concentration in the concentrated water are concentrated, with a concentrated water rate of 20%.

[0034] Step 5: The product water ends of the first spiral ultrafiltration device 3 and the second spiral ultrafiltration device 5 are connected to the second ozone oxidation device 6. After being treated by the second ozone oxidation device 6, the organic matter and color in the produced water are significantly removed.

[0035] Step 6: The product water end of the second ozone oxidation device 6 is connected to the product water tank 7 of the second ozone oxidation device, where pH adjustment can be carried out. After adjusting the pH to 8.0 - 8.5, the carbonate in the wastewater is converted into bicarbonate, and the inorganic salts exist in the form of sodium bicarbonate and sodium sulfate.

[0036] Step 7: The product water end of the product water tank 7 of the second ozone oxidation device is connected to the nanofiltration device 8. After being treated by the nanofiltration device 8, the inorganic salts in the produced water basically exist in the form of sodium bicarbonate; the inorganic salts in the concentrated water basically exist in the form of sodium sulfate. This step utilizes the characteristics of the nanofiltration device 8 to separate monovalent sodium bicarbonate salts and divalent sodium sulfate salts.

[0037] Step 8: The product water end of the nanofiltration device 8 is connected to the nanofiltration product water tank 9, where pH adjustment can be carried out. After adjusting the pH to above 10, the bicarbonate in the produced water is converted into carbonate, and the inorganic salts exist in the form of sodium carbonate.

[0038] Step 9: The water production end of the nanofiltration water production pool 9 is connected to the resin device 10. After being treated by the resin device 10, almost all calcium and magnesium ions in the produced water are removed, reducing the risk of carbonate structure in the subsequent devices.

[0039] Step 10: The water production end of the resin device 10 is connected to the second RO device 11. After being treated by the second RO device 11, the produced water has excellent quality and can be directly reused as pure water; the concentrated water concentrates a large amount of sodium carbonate inorganic salts and can be directly reused as concentrated sodium carbonate brine.

[0040] Step 11: The concentrated water end of the second RO device 11 is connected to the second RO device concentrated water pool 12, and the water production ends of the second RO device 11 and the third RO device 13 are both connected to the RO device water production pool 15. The second RO device concentrated water pool 12 serves as a storage pool for concentrated sodium carbonate inorganic salts brine, and the RO device water production pool 15 serves as a storage pool for pure water.

[0041] Step 12: The concentrated water end of the nanofiltration device 8 is connected to the third RO device 13. After being treated by the third RO device 13, the produced water has excellent quality and can be directly reused as pure water; the concentrated water concentrates a large amount of sulfuric acid inorganic salts and can be directly reused as concentrated sodium sulfate brine.

[0042] Step 13: The concentrated water end of the third RO device 13 is connected to the third RO device concentrated water pool 14, and the water production ends of the second RO device 11 and the third RO device 13 are both connected to the RO device water production pool 15. The third RO device concentrated water pool 14 serves as a storage pool for concentrated sodium sulfate inorganic salts brine, and the RO device water production pool 15 serves as a storage pool for pure water.

[0043] Step 14: The concentrated water end of the second spiral ultrafiltration device 5 is connected to the evaporation device 16. After being treated by the evaporation device 16, the waste liquid is evaporated to achieve zero discharge of the system wastewater, and the remaining dried solid substances are collected and processed.

[0044] Step 15: The discharged end of the dried solid substances of the evaporation device 16 is connected to the solid waste storage device 17, and the solid waste is collected and processed uniformly.

[0045] The utility model has the following advantages: 1. Aiming at the characteristics of high salt content in the RO concentrate of printing and dyeing wastewater, the direct external discharge causes problems of resource waste and environmental pollution. A treatment system for the RO concentrate of printing and dyeing wastewater is designed, which can recycle the water and inorganic salts in the RO concentrate and achieve zero discharge of printing and dyeing wastewater; 2. Aiming at the problem of a large amount of energy consumption caused by using the MVR evaporation process for end treatment in the existing salt recycling process of RO concentrate of printing and dyeing wastewater, the inorganic salts are concentrated by two sets of reverse osmosis devices in the system, so that the inorganic salts are directly recycled in the form of a concentrated brine solution, replacing the MVR evaporation device to recycle solid salts and reducing energy consumption. 3. Aiming at the problem of waste of sodium carbonate resources in the RO concentrate of printing and dyeing wastewater caused by the existing technology, the two inorganic salts can be separated by the nanofiltration device in the system to achieve the purpose of recovering sodium carbonate salts.

[0046] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A system for the resource utilization of RO concentrate from printing and dyeing wastewater, characterized in that: It includes a first RO device, a first spiral ultrafiltration device, a first ozone oxidation device, a second spiral ultrafiltration device, a second ozone oxidation device, a water production pool of the second ozone oxidation device, a nanofiltration device, a nanofiltration water production pool, and a resin device that are arranged in sequence.

2. The RO concentrated water resource utilization system for printing and dyeing wastewater according to claim 1, characterized in that: The first RO device is connected to a water production pool of the first RO device.

3. The RO concentrated water resource utilization system for printing and dyeing wastewater according to claim 1, characterized in that: The resin device is connected to a second RO device.

4. The resource utilization system for RO concentrate of printing and dyeing wastewater according to claim 3, characterized in that: The nanofiltration device is connected to a third RO device.

5. The resource utilization system for RO concentrate of printing and dyeing wastewater according to claim 4, characterized in that: The second RO device is connected to a concentrated water pool of the second RO device, and the third RO device is connected to a concentrated water pool of the third RO device.

6. The resource utilization system for RO concentrate of printing and dyeing wastewater according to claim 5, characterized in that: The second RO device and the third RO device are commonly connected to a water production pool of the RO device.

7. The RO concentrate water resource utilization system for printing and dyeing wastewater according to claim 1, characterized in that: The second spiral ultrafiltration device is connected to an evaporation device, and the evaporation device is connected to a solid waste storage device.

Images