Electroplating wastewater zero discharge process based on roll-type packaged RO (Reverse Osmosis) membrane

Abstract

The invention discloses an electroplating wastewater zero-discharge process based on a roll-type packaged RO membrane, and relates to the field of wastewater discharge, and the electroplating wastewater zero-discharge process comprises the following steps: S1, micro-electrolysis treatment; s2, advanced oxidation treatment; s3, ultrafiltration treatment: the electroplating wastewater subjected to advanced oxidation treatment enters a first-stage RO device, effluent of the first-stage RO device enters a second-stage RO device and then enters a concentrated water RO membrane device, effluent of a concentrated water RO membrane is recycled, concentrated water enters the concentrated water RO membrane device to be filtered again, produced water generated by the concentrated water RO device is recycled for production, and the concentrated water enters an ultrahigh-pressure RO device to be concentrated again; and S4, evaporation treatment. According to the electroplating wastewater zero-discharge process based on the roll-type packaged RO membrane, when the electroplating wastewater is discharged, the dosage of chemicals can be effectively reduced, and organic matters in the electroplating wastewater can be removed by utilizing a chemical oxidation method, so that the whole process is more stable and simpler, and the process is high in water recovery rate, stable in water quality and low in cost. And the generation amount of concentrated water is less.

Description

Technical Field

[0001] The present invention relates to the field of wastewater discharge, and in particular to a zero-discharge process for electroplating wastewater based on a roll-to-roll packaged RO membrane. Background Art

[0002] The sources of electroplating wastewater are generally plated cleaning water, waste plating solution, and other wastewater, including water used to wash the workshop floor, plate washing water, condensed water from ventilation equipment, and various tank liquids and drainage caused by "running, bubbling, dripping, and leaking" due to leakage of the plating tank or improper operation and management; equipment cooling water. The cooling water is not polluted except for the increase in temperature during use. The water quality and water volume of electroplating wastewater are related to factors such as the process conditions, production load, operation management and water use methods of electroplating production. The water quality of electroplating wastewater is complex and its composition is difficult to control. It contains heavy metal ions and cyanide such as chromium, cadmium, nickel, copper, zinc, gold, silver, etc. Some of them are highly toxic substances that are carcinogenic, teratogenic, and mutagenic.

[0003] In the existing technology, the treatment and reuse process of electroplating wastewater mostly uses coagulation and sedimentation to remove metal ions and biochemical processes to remove organic matter, but it cannot remove the salt in the wastewater and cannot completely remove the organic matter in the wastewater.

[0004] Therefore, it is necessary to propose a zero-discharge process for electroplating wastewater based on roll-to-roll RO membrane to solve the above problems. Summary of the Invention

[0005] The main purpose of the present invention is to provide a zero-discharge process for electroplating wastewater based on a roll-to-roll packaged RO membrane, which can effectively solve the problems in the background technology.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane includes the following steps:

[0008] S1: Micro-electrolysis treatment: electroplating wastewater is transported by a lift pump through a micro-electrolysis reactor equipped with an aeration and mixing device. The electroplating wastewater enters a water pool filled with micro-electrolysis fillers under acidic conditions. The micro-electrolysis fillers undergo redox reactions under acidic conditions, generating highly oxidizing free radicals that break down large organic molecules in the water into small organic molecules. This is used to remove COD, reduce color, and improve biodegradability in electroplating wastewater.

[0009] S2: Advanced oxidation treatment, adding hydrogen peroxide to the water for reaction. The ferrous sulfate produced by the micro-electrolysis reaction reacts with the added hydrogen peroxide under acidic pH conditions to generate highly oxidizing OH- ions, which are used to interrupt the chemical chain of organic matter in the water, turning large organic matter into small molecular organic matter, and reducing the organic matter content of the wastewater. After the advanced oxidation, the effluent enters the quartz sand filtration, activated carbon filtration and ultrafiltration device for filtration in turn to further remove impurities and colloids in the water;

[0010] S3: Ultrafiltration treatment, the electroplating wastewater after advanced oxidation treatment enters the primary RO device, and the effluent of the primary RO device enters the secondary RO device, where organic matter and salt are removed, and the effluent of the secondary RO device is reused for production. The salt and organic solution retained by the primary RO membrane is discharged as the membrane concentrate and enters the concentrate RO membrane device, where it is further filtered. The effluent of the concentrate RO membrane is reused, and the concentrate enters the concentrated concentrate RO membrane device for further filtration. The produced water produced by the concentrated concentrate RO device is reused for production, and the concentrate enters the ultra-high pressure RO device for further concentration.

[0011] S4: Evaporation treatment: the electroplating wastewater is input into the evaporation device, the electroplating wastewater in the evaporation device is heated to 100°C, and circulated continuously in the evaporation chamber of the equipment through a circulation pump. The water in the wastewater evaporates and separates from the pollutants, and the organic matter and salt form solids. The water vapor is condensed and reused as water.

[0012] Preferably, the first-stage RO device uses a Hyde Energy low-pressure anti-pollution reverse osmosis membrane, model number PRO-XR1 or PROC30, with a filtration pressure of 1.5-3.0 MPA and a recovery rate of 70-75%.

[0013] Preferably, the secondary RO device uses a Hyde Energy low-pressure anti-pollution reverse osmosis membrane, model PROC10, with a filtration pressure of 1.5-1.8 MPA and a recovery rate of 75-80%.

[0014] Preferably, the concentrated water RO membrane adopts one of Hyde Energy's medium-pressure and high-pressure anti-pollution reverse osmosis membranes, wherein the high-pressure anti-pollution reverse osmosis membrane is one of PRO-XR1 and PRO-LF1, the filtration pressure is 2.5-4.0 MPA, and the recovery rate is 65-70%.

[0015] Preferably, the concentrated water RO membrane adopts Hyde Energy high-pressure anti-pollution reverse osmosis membrane, model PRO-LF1, with a filtration pressure of 3.5-5.0 MPA and a recovery rate of 50-55%.

[0016] Preferably, the ultra-high pressure RO membrane in the ultra-high pressure RO device adopts Hyde Energy ultra-high pressure anti-pollution reverse osmosis membrane, model PRO-XP1, with a filtration pressure of 7.5 MPA or more and a recovery rate of 30-35%.

[0017] Preferably, the RO membrane needs to be cleaned with hydrochloric acid and sodium hydroxide after one and a half years of use. The ultra-high pressure RO device is equipped with a high-pressure pump, a membrane assembly, and a pressure control instrument.

[0018] Compared with the existing technology, the present invention provides a zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane, which has the following beneficial effects:

[0019] 1. The zero-discharge process for electroplating wastewater based on roll-type encapsulated RO membrane can effectively reduce the dosage of reagents when discharging electroplating wastewater, and can use chemical oxidation methods to remove organic matter in electroplating wastewater, making the overall process more stable and simpler. In addition, this process has a high water recovery rate, stable water quality, and less concentrated water production.

[0020] 2. The zero-discharge process for electroplating wastewater based on roll-type encapsulated RO membrane adopts a primary RO device, a secondary RO device, a concentrated water RO device and an ultra-high-pressure RO device. It can be used for the treatment and reuse of high-concentration wastewater, zero discharge and process treatment, and can be effectively applied to liquid desalination / concentration. It can also operate stably and economically for a long time under high salinity and high COD conditions. It can be widely used in the treatment and reuse of steel industry wastewater, electroplating wastewater treatment and reuse, material concentration, and brackish water desalination. At the same time, since membrane separation is a physical filtration method, it is less affected by external factors and has a very high retention rate for inorganic salts and most COD, which can effectively ensure the water quality of the effluent. The membrane component has a design operating pressure of up to 120 bar, which can achieve high-fold concentration of the liquid to reduce the amount of concentrated liquid processed and reduce the investment cost and operating cost of subsequent treatment equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0023] like Figure 1 As shown, a zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane includes the following steps:

[0024] S1: Micro-electrolysis treatment: electroplating wastewater is transported by a lift pump through a micro-electrolysis reactor equipped with an aeration and mixing device. The electroplating wastewater enters a water pool filled with micro-electrolysis fillers under acidic conditions. The micro-electrolysis fillers undergo redox reactions under acidic conditions, generating highly oxidizing free radicals that break down large organic molecules in the water into small organic molecules. This is used to remove COD, reduce color, and improve biodegradability in electroplating wastewater.

[0025] S2: Advanced oxidation treatment, adding hydrogen peroxide to the water for reaction. The ferrous sulfate produced by the micro-electrolysis reaction reacts with the added hydrogen peroxide under acidic pH conditions to generate highly oxidizing OH- ions, which are used to interrupt the chemical chain of organic matter in the water, turning large organic matter into small molecular organic matter, and reducing the organic matter content of the wastewater. After the advanced oxidation, the effluent enters the quartz sand filtration, activated carbon filtration and ultrafiltration device for filtration in turn to further remove impurities and colloids in the water;

[0026] S3: Ultrafiltration treatment, the electroplating wastewater after advanced oxidation treatment enters the primary RO device, and the effluent of the primary RO device enters the secondary RO device, where organic matter and salt are removed, and the effluent of the secondary RO device is reused for production. The salt and organic solution retained by the primary RO membrane is discharged as the membrane concentrate and enters the concentrate RO membrane device, where it is further filtered. The effluent of the concentrate RO membrane is reused, and the concentrate enters the concentrated concentrate RO membrane device for further filtration. The produced water produced by the concentrated concentrate RO device is reused for production, and the concentrate enters the ultra-high pressure RO device for further concentration.

[0027] The first-stage RO device adopts Hyde's low-pressure anti-pollution reverse osmosis membrane, model PRO-XR1 and PROC30, with a filtration pressure of 1.5-3.0MPA and a recovery rate of 70-75%; the second-stage RO device adopts Hyde's low-pressure anti-pollution reverse osmosis membrane, model PROC10, with a filtration pressure of 1.5-1.8MPA and a recovery rate of 75-80%; the concentrated water RO membrane adopts Hyde's medium-pressure and high-pressure anti-pollution reverse osmosis membrane, of which the high-pressure anti-pollution reverse osmosis membrane adopts one of PRO-XR1 and PRO-LF1, with a filtration pressure of 2.5-4.0MPA, with a recovery rate of 65-70%; the concentrated water RO membrane uses Hyde Energy's high-pressure anti-pollution reverse osmosis membrane, model PRO-LF1, with a filtration pressure of 3.5-5.0MPA and a recovery rate of 50-55%; the ultra-high-pressure RO membrane in the ultra-high-pressure RO device uses Hyde Energy's ultra-high-pressure anti-pollution reverse osmosis membrane, model PRO-XP1, with a filtration pressure of more than 7.5MPA and a recovery rate of 30-35%; the RO membrane needs to be cleaned with hydrochloric acid and sodium hydroxide after one and a half years of use. The ultra-high-pressure RO device is equipped with a high-pressure pump, membrane assembly, and pressure control instrument;

[0028] S4: Evaporation treatment: the electroplating wastewater is input into the evaporation device, the electroplating wastewater in the evaporation device is heated to 100°C, and circulated continuously in the evaporation chamber of the equipment through a circulation pump. The water in the wastewater evaporates and separates from the pollutants, and the organic matter and salt form solids. The water vapor is condensed and reused as water.

[0029] The performance of this process is compared with that of the existing process, wherein this process is recorded as an embodiment and the existing process is recorded as a comparative example. The following is a comparison table:

[0030] Overall process investment (%) Operating costs (%) Recovery rate (%) Example 60-65 55-60 80 Comparative Example 1 90-95 90-95 60 Comparative Example 2 95-100 95-100 55

[0031] This shows that this process is superior in both cost and performance.

[0032] This method can effectively reduce the dosage of reagents when discharging electroplating wastewater, and can use chemical oxidation to remove organic matter in the electroplating wastewater, making the overall process more stable and simpler. In addition, this process has a high water recovery rate, stable water quality, and a small amount of concentrated water. By adopting a primary RO device, a secondary RO device, a concentrated water RO device and an ultra-high pressure RO device, it can be used for high-concentration wastewater treatment and reuse, zero emission and process treatment, and can be effectively applied to liquid desalination / concentration. It can also operate stably and economically for a long time under high salinity and high COD conditions. It can be widely used in the fields of steel industry wastewater treatment and reuse, electroplating wastewater treatment and reuse, material concentration, and brackish water desalination. At the same time, since membrane separation is a physical filtration method, it is less affected by external factors and has an extremely high retention rate for inorganic salts and most COD, which can effectively ensure the water quality of the effluent; the membrane component has a design operating pressure of up to 120 bar, which can achieve high-fold concentration of the liquid, thereby reducing the concentrate treatment volume and reducing the investment cost and operating cost of subsequent treatment equipment.

[0033] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane, characterized by: The following steps are included: S1: Micro-electrolysis treatment: electroplating wastewater is transported by a lift pump through a micro-electrolysis reactor equipped with an aeration and mixing device. The electroplating wastewater enters a water pool filled with micro-electrolysis fillers under acidic conditions. The micro-electrolysis fillers undergo redox reactions under acidic conditions, generating highly oxidizing free radicals that break down large organic molecules in the water into small organic molecules. This is used to remove COD, reduce color, and improve biodegradability in electroplating wastewater. S2: Advanced oxidation treatment, adding hydrogen peroxide to the water for reaction. The ferrous sulfate produced by the micro-electrolysis reaction reacts with the added hydrogen peroxide under acidic pH conditions to generate highly oxidizing OH- ions, which are used to interrupt the chemical chain of organic matter in the water, turning large organic matter into small molecular organic matter, and reducing the organic matter content of the wastewater. After the advanced oxidation, the effluent enters the quartz sand filtration, activated carbon filtration and ultrafiltration device for filtration in turn to further remove impurities and colloids in the water; S3: Ultrafiltration treatment, the electroplating wastewater after advanced oxidation treatment enters the primary RO device, and the effluent of the primary RO device enters the secondary RO device, where organic matter and salt are removed, and the effluent of the secondary RO device is reused for production. The salt and organic solution retained by the primary RO membrane is discharged as the membrane concentrate and enters the concentrate RO membrane device, where it is further filtered. The effluent of the concentrate RO membrane is reused, and the concentrate enters the concentrated concentrate RO membrane device for further filtration. The produced water produced by the concentrated concentrate RO device is reused for production, and the concentrate enters the ultra-high pressure RO device for further concentration. S4: Evaporation treatment: the electroplating wastewater is input into the evaporation device, the electroplating wastewater in the evaporation device is heated to 100°C, and circulated continuously in the evaporation chamber of the equipment through a circulation pump. The water in the wastewater evaporates and separates from the pollutants, and the organic matter and salt form solids. The water vapor is condensed and reused as water.

2. The zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane according to claim 1, characterized in that: The first-stage RO device uses a Hyde Energy low-pressure anti-pollution reverse osmosis membrane, model number PRO-XR1 or PROC30, with a filtration pressure of 1.5-3.0 MPA and a recovery rate of 70-75%.

3. The zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane according to claim 1, characterized in that: The secondary RO device adopts Hyde Energy low-pressure anti-pollution reverse osmosis membrane, model PROC10, with a filtration pressure of 1.5-1.8 MPA and a recovery rate of 75-80%.

4. The zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane according to claim 1, characterized in that: The concentrated water RO membrane adopts one of Hyde Energy's medium-pressure and high-pressure anti-pollution reverse osmosis membranes, wherein the high-pressure anti-pollution reverse osmosis membrane adopts one of PRO-XR1 and PRO-LF1, the filtration pressure is 2.5-4.0MPA, and the recovery rate is 65-70%.

5. The zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane according to claim 1, characterized in that: The concentrated water RO membrane adopts Hyde Energy high-pressure anti-pollution reverse osmosis membrane, model PRO-LF1, with a filtration pressure of 3.5-5.0 MPA and a recovery rate of 50-55%.

6. The zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane according to claim 1, characterized in that: The ultra-high pressure RO membrane in the ultra-high pressure RO device adopts Hyde Energy ultra-high pressure anti-pollution reverse osmosis membrane, model PRO-XP1, with a filtration pressure of more than 7.5 MPA and a recovery rate of 30-35%.

7. The zero-discharge process for electroplating wastewater based on a roll-to-roll RO membrane according to claim 6, characterized in that: The RO membrane needs to be cleaned with hydrochloric acid and sodium hydroxide after one and a half years of use. The ultra-high pressure RO device is equipped with a high-pressure pump, a membrane assembly, and a pressure control instrument.

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