Stainless steel pickling horizontal flow tank wastewater reverse osmosis treatment process

Abstract

The application discloses a stainless steel pickling horizontal flow pool wastewater reverse osmosis treatment process, which comprises the following specific steps: S1: after the stainless steel pickling wastewater is subjected to neutralization and clarification treatment in a horizontal flow sedimentation tank, the wastewater is pumped into a filter by a water pump for pretreatment, and particulate matters with a diameter greater than 1 mu m are filtered out; S2: the filtered water is pumped into a reverse osmosis membrane system one by a high-pressure pump A, and first-stage concentrated water generated is introduced into a concentrated water concentration system; the first-stage water is introduced into a reverse osmosis membrane system two under the action of a high-pressure pump B; S3: second-stage water generated after passing through the reverse osmosis membrane system two is discharged through a second-stage water drainage port A and a second-stage water drainage port B respectively. The stainless steel pickling horizontal flow pool wastewater reverse osmosis treatment process disclosed by the application has the effects of reducing the water quantity of concentrated water, reducing the energy consumption of a later-stage evaporation process, reducing the operation cost of a user, avoiding damage to a reverse osmosis membrane system and guaranteeing the maintenance cost of the reverse osmosis membrane system.

Description

Technical Field

[0001] This invention relates to the field of reverse osmosis treatment technology, and in particular to a reverse osmosis treatment process for wastewater from stainless steel pickling horizontal flow tanks. Background Technology

[0002] The treatment of stainless steel pickling wastewater requires primary lime neutralization followed by filtration or precipitation clarification. Currently, this project faces two main problems: the salinity of the aqueous solution entering the evaporation system is too low, resulting in a large volume of water evaporated and high energy consumption.

[0003] Given that the salt content of the clarified water from the first-stage reaction is about 2%, which is close to the salt content of seawater, and based on the existing reverse osmosis membrane desalination efficiency (99%), a second-stage reverse osmosis system must be used to ensure that its effluent indicators can meet the standards for direct discharge.

[0004] Generally, there are two options for the concentrate produced after reverse osmosis treatment: direct discharge and concentrate concentration. The latter can reduce the amount of concentrate, reduce the energy consumption of the downstream evaporation process, and reduce the user's operating costs. However, the concentrate concentration process will greatly aggravate the damage to the reverse osmosis membrane system and may lead to greater cost expenditures. Summary of the Invention

[0005] This invention discloses a reverse osmosis treatment process for wastewater from stainless steel pickling horizontal flow tanks, aiming to solve the technical problem that the concentrated water process can greatly aggravate the damage to the reverse osmosis membrane system, which may lead to greater cost expenditures.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The reverse osmosis treatment process for stainless steel pickling wastewater from a horizontal flow sedimentation tank includes the following specific steps: S1: After reaction neutralization and clarification in a horizontal flow sedimentation tank, the stainless steel pickling wastewater is pumped into a filter for pretreatment to remove particulate matter with a diameter >1μm; S2: The permeate after filtration is pumped into reverse osmosis membrane system one by high-pressure pump A. The resulting primary concentrate enters the concentrate concentration system, and the primary permeate enters reverse osmosis membrane system two under the action of high-pressure pump B; S3: The secondary permeate produced after passing through reverse osmosis membrane system two is discharged from secondary permeate outlet A and secondary permeate outlet B respectively. The resulting secondary concentrate is divided into two parts: one part is recycled and mixed with the pretreated water, continuing step S1, and the other part enters the concentrate concentration system; S4: The phases in reverse osmosis membrane system one, reverse osmosis membrane system two, and concentrate concentration system are periodically... The filtration equipment is shut off and emptied, and an alkaline cleaning system is used to remove calcium sulfate scale, organic matter, and oil clogging. In step S2, the concentrated water system's processing flow includes the following specific steps: S21: Primary concentrate enters a concentrated water storage tank for temporary storage; S22: The flow rate of secondary concentrate entering the concentrated water system is measured and monitored by a flow meter, and the flow rate in the concentrated water storage tank is controlled by a high-pressure pump F, pumping it into the reverse osmosis membrane system three, which has the same specifications as reverse osmosis membrane system one; S23: The tertiary concentrate produced by reverse osmosis membrane system three repeats step S22 again, and the resulting tertiary permeate is recycled and mixed with the pretreated water, continuing step S1; S24: In S23, after the tertiary concentrate is recycled twice, the resulting concentrated concentrate is directly discharged; S25: The concentrated water in the concentrated water storage tank is again drawn from the tank by the high-pressure pump F for compression.

[0008] The reverse osmosis membrane system two and reverse osmosis membrane system three are connected by a first water pipe. A filter chamber is provided in the middle section of the first water pipe. A second water pipe is tightly connected to the inner wall of the other side of the filter chamber. The second water pipe is used to establish a connection with the pre-treated water channel. A high-pressure pump G is provided in the middle section of the first water pipe. A high-pressure pump H is provided in the middle section of the second water pipe. The power of the high-pressure pump G is greater than the power of the high-pressure pump H. A filter membrane assembly is provided in the middle section of the filter chamber. The second water pipe is located at the bottom end of the filter membrane assembly.

[0009] The filter uses a combination of sand filtration and ultrafiltration membrane system to pretreat the incoming water;

[0010] In S3, after passing through the reverse osmosis membrane system two, particulate matter with a diameter of <0.02μm can be filtered out;

[0011] In S3, the secondary product water discharged from the secondary product water outlet A is directly discharged into the product water tank for reuse or mixed with the distilled water of the evaporation system before being discharged in compliance with standards.

[0012] By incorporating a concentrate concentration system, there are generally two options for handling the concentrate produced after reverse osmosis treatment: direct discharge and concentrate concentration. The latter reduces the volume of concentrate, lowers the energy consumption of the downstream evaporation process, and reduces user operating costs. However, concentrate concentration significantly increases damage to the reverse osmosis membrane system, potentially leading to higher costs. In this concentrate concentration system, a third reverse osmosis membrane system is incorporated. This third system has the same specifications as the first system but can be of lower quality, lower cost, or even a used reverse osmosis membrane system. This reduces the consumption cost of the reverse osmosis membrane system. Simultaneously, by mixing the secondary and tertiary concentrates to dilute the tertiary concentrate, the secondary concentrate is fully utilized while reducing the damage to the third reverse osmosis membrane system caused by direct concentration of the tertiary concentrate. With this concentrate treatment structure, the volume of concentrate is reduced, the energy consumption of the downstream evaporation process is lowered, and the cost of direct discharge is reduced. While reducing user operating costs, this design also avoids damage to the reverse osmosis membrane system, ensuring its maintenance costs. Furthermore, through the filter chamber setup, when the secondary concentrate is discharged through the first water pipe, it is diverted through the second water pipe. Part of it mixes with the primary concentrate and the returned tertiary concentrate before entering the reverse osmosis membrane system. The other part mixes with the pretreated water. During this process, the filter membranes separate the secondary concentrate, allowing the higher concentration concentrate to mix with the pretreated water, while the lower concentration concentrate dilutes the tertiary concentrate. Therefore, since the quality of the secondary concentrate is significantly better than the pretreated water, even after filtration by the filter membranes, its quality remains superior. The lower concentration concentrate after filtration by the filter modules, when mixed with the tertiary concentrate, effectively enhances the dilution of the tertiary concentrate, thus better protecting the lifespan of the reverse osmosis membrane system and better achieving the fusion and utilization of concentrates from each stage.

[0013] In a preferred embodiment, the chemical cleaning system in step S4 includes the following specific steps: S41: The secondary permeate discharged from the secondary permeate outlet B is quantitatively fed into the cleaning solution mixing tank for later use, controlled by a flow meter; S42: The cleaning agent is added to the cleaning solution mixing tank and mixed evenly with the secondary permeate, and then pumped into reverse osmosis membrane system one, reverse osmosis membrane system two, and reverse osmosis membrane system three respectively through high-pressure pump C to perform alkaline cleaning on the calcium sulfate scale, organic matter, and oil blockage; S43: The waste cleaning solution after cleaning and filtration by the chemical cleaning system is mixed with the pretreated incoming water, and step S1 continues.

[0014] The cleaning solution is a mixture of alkaline solution and citric acid.

[0015] By installing a chemical cleaning system that is directly connected to the secondary permeable water system, the preparation of cleaning solution is facilitated, avoiding the need to re-introduce tap water. At the same time, the water quality of the secondary permeable water fully meets the cleaning requirements. Through water recycling, the consumption of tap water can be avoided, reducing costs. Furthermore, by filtering the cleaning solution and mixing the filtered waste cleaning solution with the pretreated water for permeation filtration, water waste is further avoided, thus implementing the concept of environmental protection.

[0016] In a preferred embodiment, step S42 specifically includes the following steps: S421: Under the action of high-pressure pump C, reverse osmosis membrane system one, reverse osmosis membrane system two, and reverse osmosis membrane system three are cleaned. The cleaned solution enters the three-way separation filter tank A for filtration, and the filtered cleaned solution is extracted by high-pressure pump D; S422: During the second clean, the cleaned solution filtered in the three-way separation filter tank A is used for pre-cleaning. Then, the cleaned solution mixing tank is regulated by switching valve B to introduce fresh cleaned solution into the three-way separation filter tank B, and the cleaned solution in the three-way separation filter tank B is switched by switching valve C. Perform a second round of cleaning; S423: Store the cleaning solution generated after each round of cleaning in batches. The cleaning solution is filtered in the three-stage separation filter tank B and then extracted by the high-pressure pump E; S424: Control the use of cleaning solution in three-stage separation filter tanks A and B through switching valve A, ensuring that the cleaning solution in each three-stage separation filter tank is recycled three times. When three-stage separation filter tanks A and B are used together, the cleaning solution with the worse cleaning effect is used for pre-cleaning; S425: The cleaning solution after being recycled three times is the waste cleaning solution, which is mixed with the pre-treated water;

[0017] The three-stage separation filtration tank filters by sedimentation, causing calcium sulfate scale and organic matter to precipitate, while oil floats to the top, and the cleaning solution located in the middle is extracted.

[0018] By incorporating a three-stage filtration system, which filters out large particles and oil through sedimentation, the cleaning solution can be reused while also meeting the requirement of mixing with pretreated water. Furthermore, by alternating between three-stage filtration tanks A and B, a low-cleaning-power cleaning solution is used for pre-washing, followed by a high-cleaning-power cleaning solution for secondary rinsing. This fully utilizes the cleaning solution while reducing the difficulty of secondary rinsing, thereby ensuring the quality of the cleaning solution for multiple uses and reducing the cleaning cost of the reverse osmosis membrane system.

[0019] As shown above, the reverse osmosis treatment process for stainless steel pickling wastewater from the horizontal flow sedimentation tank includes the following specific steps: S1: After reaction neutralization and clarification in the horizontal flow sedimentation tank, the stainless steel pickling wastewater is pumped into a filter for pretreatment to remove particulate matter with a diameter >1μm; S2: The permeate after filtration is pumped into reverse osmosis membrane system one by high-pressure pump A, and the resulting primary concentrate enters the concentrate concentration system. The primary permeate then enters reverse osmosis membrane system two under the action of high-pressure pump B; S3: The secondary permeate produced after passing through reverse osmosis membrane system two... The secondary product water is discharged from the secondary product water outlets A and B, and the generated secondary concentrate is divided into two parts. One part is returned and mixed with the pretreated water, continuing in step S1, and the other part enters the concentrate concentration system; S4: The relevant filtration equipment in reverse osmosis membrane system one, reverse osmosis membrane system two, and concentrate concentration system are emptied periodically, and alkaline cleaning is performed on the calcium sulfate scale, organic matter, and oil clogging by the chemical cleaning system; In S2, the treatment process of the concentrate concentration system includes the following specific steps: S21: Primary concentrate enters the concentrate system. S22: The flow rate of the secondary concentrate entering the concentrate concentration system is measured and monitored by a flow meter, and the flow rate of the concentrate in the concentrate storage tank is controlled by a high-pressure pump F, which pumps it into the reverse osmosis membrane system three, where the reverse osmosis membrane system three has the same specifications as the reverse osmosis membrane system one; S23: The tertiary concentrate produced by the reverse osmosis membrane system three repeats S22 again, and the resulting tertiary permeate is mixed with the pretreated water and continues in step S1; S24: In S23, after the tertiary concentrate is repeatedly refluxed twice, the resulting concentrated concentrate is directly discharged; S25: Again through High-pressure pump F draws concentrated water from the concentrated water storage tank for compression. Reverse osmosis membrane system two and reverse osmosis membrane system three are connected via a first water pipe. A filter chamber is located in the middle section of the first water pipe. A second water pipe is tightly connected to the inner wall of the other side of the filter chamber, and this second water pipe establishes communication with the pretreated water channel. A high-pressure pump G is located in the middle section of the first water pipe, and a high-pressure pump H is located in the middle section of the second water pipe. The power of high-pressure pump G is greater than that of high-pressure pump H. A filter membrane assembly is located in the middle section of the filter chamber, and the second water pipe is located at the bottom of the filter membrane assembly. The stainless steel pickling horizontal flow tank wastewater reverse osmosis treatment process provided by this invention has the technical effect of reducing the volume of concentrated water, reducing the energy consumption of the downstream evaporation process, and reducing user operating costs, while also avoiding damage to the reverse osmosis membrane system and ensuring low maintenance costs for the reverse osmosis membrane system. Attached Figure Description

[0020] Figure 1 This is an overall flow chart of the reverse osmosis treatment process for wastewater from a stainless steel pickling horizontal flow tank proposed in this invention.

[0021] Figure 2 This is a flow chart of the concentrated water system for the reverse osmosis treatment process of stainless steel pickling horizontal flow tank wastewater proposed in this invention.

[0022] Figure 3 This is a schematic diagram of the connection structure of reverse osmosis membrane system two and reverse osmosis membrane system three in the reverse osmosis treatment process of stainless steel pickling horizontal flow tank wastewater proposed in this invention.

[0023] Figure 4 This is a schematic diagram of the filtration structure at the connection point of reverse osmosis membrane system two and reverse osmosis membrane system three in the reverse osmosis treatment process for stainless steel pickling horizontal flow tank wastewater proposed in this invention.

[0024] Figure 5 This is a flow chart of the chemical cleaning system for the reverse osmosis treatment process of stainless steel pickling wastewater from a horizontal flow tank, as proposed in this invention.

[0025] In the diagram: 1. Reverse osmosis membrane system one; 2. Reverse osmosis membrane system two; 3. Reverse osmosis membrane system three; 4. Filter chamber; 5. High-pressure pump G; 6. First water pipe; 7. Second water pipe; 8. High-pressure pump H; 9. Filter membrane assembly. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] The reverse osmosis treatment process for stainless steel pickling horizontal flow tank wastewater disclosed in this invention is mainly applied to the treatment of stainless steel pickling horizontal flow tank wastewater.

[0028] Reference Figures 1-4The reverse osmosis treatment process for stainless steel pickling wastewater from a horizontal flow sedimentation tank includes the following specific steps: S1: After reaction neutralization and clarification in a horizontal flow sedimentation tank, the stainless steel pickling wastewater is pumped into a filter for pretreatment to remove particulate matter with a diameter >1μm; S2: The permeate after filtration is pumped into reverse osmosis membrane system 1 by high-pressure pump A. The resulting primary concentrate enters the concentrate concentration system, and the primary permeate enters reverse osmosis membrane system 2 under the action of high-pressure pump B; S3: The secondary permeate produced after passing through reverse osmosis membrane system 2 is discharged from secondary permeate outlets A and B, respectively. The resulting secondary concentrate is divided into two parts: one part is recycled and mixed with the pretreated water, continuing step S1, and the other part enters the concentrate concentration system; S4: The reverse osmosis membrane system 1 and reverse osmosis membrane system 2 are periodically emptied. Membrane system 2 and related filtration equipment in the concentrate system are emptied, and alkaline cleaning is performed on the calcium sulfate scale, organic matter, and oil clogging by the chemical cleaning system. In S2, the treatment process of the concentrate system includes the following specific steps: S21: Primary concentrate enters the concentrate storage tank for temporary storage; S22: The flow rate of secondary concentrate entering the concentrate system is measured and monitored by a flow meter, and the flow rate of concentrate in the concentrate storage tank is controlled by a high-pressure pump F, which pumps it into reverse osmosis membrane system 3, wherein reverse osmosis membrane system 3 has the same specifications as reverse osmosis membrane system 1; S23: The tertiary concentrate produced by reverse osmosis membrane system 3 is repeated in S22, and the resulting tertiary permeate is mixed with the pretreated water and continues in step S1; S24: In S23, after the tertiary concentrate is repeatedly refluxed twice, the resulting concentrated concentrate is directly discharged.S25: High-pressure pump F is used again to extract concentrated water from the concentrated water storage tank for compression. Reverse osmosis membrane system 2 and reverse osmosis membrane system 3 are connected via a first water pipe 6. A filter chamber 4 is installed in the middle section of the first water pipe 6. A second water pipe 7 is tightly connected to the inner wall of the other side of the filter chamber 4, and the second water pipe 7 is used to establish communication with the pretreated water channel. A high-pressure pump G5 is installed in the middle section of the first water pipe 6, and a high-pressure pump H8 is installed in the middle section of the second water pipe 7. The power of high-pressure pump G5 is greater than that of high-pressure pump H8. A filter chamber 4 is installed in the middle section... The filter membrane group 9 has a second water pipe 7 located at the bottom. In the concentrate system, a reverse osmosis membrane system 3 is installed. This reverse osmosis membrane system 3 has the same specifications as the reverse osmosis membrane system 1, but can be of lower quality, lower cost, or even a used reverse osmosis membrane system. This reduces the consumption cost of the reverse osmosis membrane system. Furthermore, since the quality of the secondary concentrate produced is significantly better than that of the pretreated water, the secondary concentrate is mixed with the tertiary concentrate to dilute the tertiary concentrate. This fully utilizes the secondary concentrate while also reducing costs. This design avoids the damage to the reverse osmosis membrane system caused by direct concentration of tertiary concentrate. Under this concentrate treatment structure, while reducing the volume of concentrate, lowering the energy consumption of the downstream evaporation process, and reducing user operating costs, it also avoids damage to the reverse osmosis membrane system, ensuring low maintenance costs. Furthermore, through the filter chamber 4, when the secondary concentrate is discharged through the first water pipe 6, it is diverted through the second water pipe 7. Part of it mixes with the primary concentrate and the returned tertiary concentrate before entering the reverse osmosis membrane system; the other part mixes with the pretreated water. During the process, the secondary concentrate is separated by the filter membrane module 9, and the higher concentration concentrate is mixed with the pretreated water. The lower concentration concentrate dilutes the tertiary concentrate. Therefore, since the quality of the secondary concentrate is significantly better than that of the pretreated water, even after filtration by the filter membrane module 9, its quality remains superior. Furthermore, the lower concentration concentrate after filtration by the filter module 9, when mixed with the tertiary concentrate, effectively enhances the dilution of the tertiary concentrate, thus better ensuring the service life of the reverse osmosis membrane system and better achieving the fusion and utilization of the concentrates from each stage.

[0029] Reference Figure 1 and Figure 2 In a preferred embodiment, the filter is a combination of sand filtration and ultrafiltration membrane system to pretreat the influent.

[0030] Reference Figure 1 and Figure 2 In a preferred embodiment, in S3, after passing through the reverse osmosis membrane system 2, particulate matter with a diameter <0.02μm can be filtered out.

[0031] Reference Figure 1 and Figure 2In a preferred embodiment, in S3, the secondary permeate discharged from the secondary permeate outlet A is directly discharged into the permeate tank for reuse or mixed with distilled water from the evaporation system before being discharged in compliance with standards.

[0032] Reference Figure 1 and Figure 3 In a preferred embodiment, in step S4, the chemical cleaning system process includes the following specific steps: S41: The secondary permeate discharged from the secondary permeate outlet B is quantitatively fed into the cleaning solution mixing tank for later use, controlled by a flow meter; S42: The cleaning agent is placed in the cleaning solution mixing tank and mixed evenly with the secondary permeate, and then pumped into the reverse osmosis membrane system 1, reverse osmosis membrane system 2, and reverse osmosis membrane system 3 respectively through the high-pressure pump C to perform alkaline cleaning on the existing calcium sulfate scale, organic matter, and oil blockage; S43: The waste cleaning solution cleaned and filtered by the chemical cleaning system is mixed with the pretreated incoming water, and step S1 continues.

[0033] Reference Figure 1 and Figure 3 In a preferred embodiment, the cleaning solution is a mixture of alkaline solution and citric acid. The chemical cleaning system is directly connected to the secondary water production system, which facilitates the preparation of the cleaning solution and avoids the need to reintroduce tap water. At the same time, the water quality of the secondary water production system fully meets the cleaning requirements. By recycling the water, the consumption of tap water can be avoided, reducing costs. Furthermore, by filtering the cleaning solution and mixing the filtered waste cleaning solution with the pretreated water for permeation filtration, water waste is further avoided, thus implementing the concept of environmental protection.

[0034] Reference Figure 1 and Figure 3In a preferred embodiment, in step S42, the specific cleaning method includes the following steps: S421: Under the action of high-pressure pump C, reverse osmosis membrane system 1, reverse osmosis membrane system 2, and reverse osmosis membrane system 3 are cleaned. The cleaning solution after cleaning enters the three-way separation filter tank A for filtration, and the filtered cleaning solution is extracted by high-pressure pump D; S422: During the second cleaning, the cleaning solution filtered in the three-way separation filter tank A is used for pre-cleaning. Then, the cleaning solution mixing tank is regulated by switching valve B to introduce fresh cleaning solution into the three-way separation filter tank B, and the cleaning solution in the three-way separation filter tank B is switched by switching valve C. The washing solution undergoes a second round of cleaning; S423: The washing solution generated after each round of cleaning is stored in batches, with the cleaning solution filtered in the three-stage separation filter B and then extracted by the high-pressure pump E; S424: The use of the cleaning solution in the three-stage separation filter A and the three-stage separation filter B is controlled by the switching valve A, ensuring that the cleaning solution in each three-stage separation filter is recycled three times, and when the three-stage separation filter A and the three-stage separation filter B are used together, the cleaning solution with the worse cleaning effect is used for pre-cleaning; S425: The cleaning solution after being recycled three times is the waste cleaning solution, which is mixed with the pre-treated water.

[0035] Reference Figure 1 and Figure 3 In a preferred embodiment, the three-stage separation filter uses sedimentation to precipitate calcium sulfate scale and organic matter, while oil floats to the top. The cleaning solution in the middle is then extracted. The three-stage separation filter removes large particles and oil through sedimentation, facilitating the reuse of the cleaning solution and meeting the requirement of mixing with pretreated water. Furthermore, by alternating between three-stage separation filter A and three-stage separation filter B, a low-cleaning-power cleaning solution is used for pre-washing, and a high-cleaning-power cleaning solution is used for secondary rinsing. This fully utilizes the cleaning solution while reducing the cleaning difficulty of the secondary rinsing solution. As a result, the quality of the cleaning solution can be guaranteed for multiple uses, and the cleaning cost of the reverse osmosis membrane system can be reduced.

[0036] Working Principle: In the concentrate concentration system, a reverse osmosis membrane system (system 3) is installed. This system has the same specifications as reverse osmosis membrane system (system 1), but can be of lower quality, lower cost, or even a used reverse osmosis membrane system. This reduces the operating costs of the reverse osmosis membrane system. Simultaneously, since the quality of the secondary concentrate produced is significantly better than that of the pretreated water, the secondary concentrate is mixed with the tertiary concentrate to dilute the tertiary concentrate. This fully utilizes the secondary concentrate while reducing the damage to the reverse osmosis membrane system (system 3) caused by direct concentration of the tertiary concentrate. Under this concentrate treatment structure, the amount of concentrate is reduced, and the cost is lowered. The energy consumption of the downstream evaporation process reduces user operating costs while avoiding damage to the reverse osmosis membrane system, thus ensuring low maintenance costs. Furthermore, through the filter chamber 4, when the secondary concentrate is discharged through the first water pipe 6, it is diverted through the second water pipe 7. Part of it mixes with the primary concentrate and the returned tertiary concentrate before entering the reverse osmosis membrane system; the other part mixes with the pretreated water. During this process, the filter membrane group 9 separates the secondary concentrate, allowing the higher concentration concentrate to mix with the pretreated water, while the lower concentration concentrate dilutes the tertiary concentrate. Therefore, the quality of the secondary concentrate is significantly better than that of the pretreated water, even... After filtration by membrane module 9, the quality of the treated water remains superior to that of the pretreated water. The lower concentration of the concentrate filtered by module 9, when mixed with the tertiary concentrate, effectively enhances the dilution of the tertiary concentrate, thus better ensuring the lifespan of the reverse osmosis membrane system and better achieving the fusion and utilization of concentrates from each stage. Simultaneously, since the chemical cleaning system is directly connected to the secondary permeate, the preparation of the cleaning solution is convenient, avoiding the need to reintroduce tap water. Furthermore, the water quality of the secondary permeate fully meets the cleaning requirements. Through water recycling, the consumption of tap water can be avoided, reducing costs. Additionally, by filtering the cleaning solution and... The filtered waste cleaning solution is mixed with pretreated water for percolation filtration, further avoiding water waste and implementing the concept of environmental protection. The three-stage separation filter tank filters out large particles and oil through sedimentation filtration, which facilitates the reuse of the cleaning solution and meets the requirement of mixing with pretreated water. In addition, by using three-stage separation filter tank A and three-stage separation filter tank B alternately, a cleaning solution with low cleaning power is used for pre-washing, and a cleaning solution with high cleaning power is used for secondary rinsing. This makes full use of the cleaning solution and reduces the cleaning difficulty of the secondary rinsing solution. As a result, the quality of the cleaning solution can be guaranteed for multiple uses, and the cleaning cost of the reverse osmosis membrane system can be reduced.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A wastewater reverse osmosis treatment process for stainless steel pickling stilling basin, characterized in that, The method comprises the following specific steps: S1: the stainless steel pickling wastewater is pumped into a filter by a water pump for pretreatment after reaction and neutralization and clarification treatment in a horizontal sedimentation tank, so as to filter out particles with a diameter greater than 1 μm; S2: the filtered water is pumped into a reverse osmosis membrane system 1 (1) by a high-pressure pump A, the first concentrated water is introduced into a concentrated water concentration system, and the first product water is introduced into a reverse osmosis membrane system 2 (2) under the action of a high-pressure pump B; S3: the second product water generated after the reverse osmosis membrane system 2 (2) is discharged from a second product water discharge port A and a second product water discharge port B, and the second concentrated water is divided into two parts, one part is returned and mixed with the pretreatment water to continue the step S1, and the other part is introduced into the concentrated water concentration system; S4: the reverse osmosis membrane system 1 (1), the reverse osmosis membrane system 2 (2) and the concentrated water concentration system are emptied at irregular intervals, and the chemical cleaning system is used for alkaline cleaning of the existing calcium sulfate scale and organic matter and oil blockage; In the S2, the treatment process of the concentrated water concentration system comprises the following specific steps: S21: the first concentrated water is temporarily stored in a concentrated water temporary storage tank; S22: the flow of the second concentrated water introduced into the concentrated water concentration system is measured and monitored by a flow meter, and the flow of the concentrated water in the concentrated water temporary storage tank is controlled by a high-pressure pump F and pumped into a reverse osmosis membrane system 3 (3), wherein the reverse osmosis membrane system 3 (3) is consistent with the reverse osmosis membrane system 1 (1) in specification; S23: the third concentrated water generated by the reverse osmosis membrane system 3 (3) is repeatedly S22, and the third product water is returned and mixed with the pretreatment water to continue the step S1; S24: in the S23, after the third concentrated water is repeatedly returned twice, the concentrated concentrated water is directly discharged; S25: the concentrated water in the concentrated water temporary storage tank is extracted again by the high-pressure pump F for compression; The reverse osmosis membrane system 2 (2) and the reverse osmosis membrane system 3 (3) are connected by a first water pipe (6), a filter bin (4) is arranged in the middle section of the first water pipe (6), a second water pipe (7) is tightly connected to the other side inner wall of the filter bin (4), the second water pipe (7) is used for establishing communication with the pretreatment water channel, a high-pressure pump G (5) is arranged in the middle section of the first water pipe (6), a high-pressure pump H (8) is arranged in the middle section of the second water pipe (7), the power of the high-pressure pump G (5) is greater than the power of the high-pressure pump H (8), a filter membrane group (9) is arranged in the middle section of the filter bin (4), and the second water pipe (7) is located at the bottom end of the filter membrane group (9); In the S4, the treatment process of the chemical cleaning system comprises the following specific steps: S41: the second product water discharged from the second product water discharge port B is controlled by a flow meter and quantitatively introduced into a cleaning liquid preparation tank for standby; S42: the cleaning agent is placed in the cleaning liquid preparation tank and uniformly mixed with the second product water, and is pumped into the reverse osmosis membrane system 1 (1), the reverse osmosis membrane system 2 (2) and the reverse osmosis membrane system 3 (3) by a high-pressure pump C, so as to perform alkaline cleaning on the existing calcium sulfate scale and organic matter and oil blockage. S43: the waste cleaning liquid filtered through the chemical cleaning system is mixed with the pretreated incoming water, and the process continues at S1; the cleaning liquid is a mixture of alkali and citric acid; the specific cleaning method in S42 includes the following steps: S421: the reverse osmosis membrane system 1, the reverse osmosis membrane system 2 and the reverse osmosis membrane system 3 are cleaned under the action of the high-pressure pump C, the cleaned cleaning liquid is filtered into the three-separation filter tank A, and the filtered cleaning liquid is extracted by the high-pressure pump D; S422: during the second cleaning, the filtered cleaning liquid in the three-separation filter tank A is used for pre-cleaning, the post-cleaning liquid preparation tank is connected to the three-separation filter tank B through the switch valve B to introduce fresh cleaning liquid, and the switch valve C is switched to perform two rounds of cleaning; S423: the cleaning liquid produced after each round of cleaning is stored in batches, and the cleaning liquid in the three-separation filter tank B is extracted by the high-pressure pump E after being filtered; S424: the use of the cleaning liquid in the three-separation filter tank A and the three-separation filter tank B is controlled by the switch valve A, so that the cleaning liquid in each three-separation filter tank is used three times, and when the three-separation filter tank A and the three-separation filter tank B are used together, the cleaning liquid with poor cleaning effect is used for pre-cleaning; S425: the cleaning liquid used three times is waste cleaning liquid, which is mixed with the pretreated incoming water. The three-separation filter tank filters by sedimentation, so that calcium sulfate scale and organic matter are precipitated, and oil floats, and the cleaning liquid in the middle is extracted.

2. The process for treating wastewater from reverse osmosis of stainless steel pickling stilling basin according to claim 1, characterized in that, The filter is a combination of sand filtration and ultrafiltration membrane system for pretreatment of incoming water.

3. The process for treating wastewater from reverse osmosis of stainless steel pickling stilling basin according to claim 1, characterized in that, In S3, particles with a diameter <0.02 μm can be filtered out after the reverse osmosis membrane system 2.

4. The process for treating wastewater from reverse osmosis of stainless steel pickling stilling basin according to claim 1, characterized in that, In S3, the secondary produced water discharged from the secondary produced water discharge port A is directly discharged into the produced water tank for reuse or mixed with distilled water of the evaporation system for discharge after reaching the standard.

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