CN117776436A - Reverse osmosis composite membrane rinsing liquid acid recovery system and recovery method thereof - Google Patents

Abstract

The invention discloses a reverse osmosis composite membrane rinse liquid acid recovery system and a recovery method thereof, comprising a rinse tank, a precision filter, a primary acid-resistant nanofiltration membrane system, a secondary acid-resistant nanofiltration membrane system and a dosing box, a rinse liquid delivery pipe is connected between the rinse tank and the precision filter, a filtrate pipe is connected between the precision filter and the primary acid-resistant nanofiltration membrane system, a primary water production pipe is connected between the primary acid-resistant nanofiltration membrane system and the secondary acid-resistant nanofiltration membrane system, a secondary concentrated water pipe is connected between the secondary acid-resistant nanofiltration membrane system and the filtrate pipe, and a secondary water production pipe is connected between the secondary acid-resistant nanofiltration membrane system and the dosing box. The reverse osmosis composite membrane rinse liquid acid recovery system and a recovery method thereof of the invention separates acidic wastewater in advance with an acid-resistant membrane, and reuses it after separation and purification, which not only reduces production costs, but also reduces the load of sewage treatment, acid resource utilization, reduces pollution, and improves the processing capacity of the biochemical system.

Description

A reverse osmosis composite membrane rinse liquid acid recovery system and its recovery method

Technical field

The invention relates to the technical field of wastewater recovery after treatment with a reverse osmosis composite membrane, and in particular to a reverse osmosis composite membrane rinsing liquid acid recovery system and a recovery method thereof.

Background technique

The acid recovery system for rinsing liquid of reverse osmosis composite membrane is a key equipment for wastewater recovery of reverse osmosis composite membrane treatment. In the production process of reverse osmosis composite membrane, since the composite membrane will have incompletely reacted monomers and decomposition products during the reaction process, in order to ensure the performance and stability of the composite membrane, the composite membrane will be rinsed through a series of rinsing tanks at the end of the reaction. Acid rinsing is an indispensable process in most reverse osmosis membrane production processes. The treatment of acidic wastewater after rinsing requires a large amount of chemical agents and has an impact on biochemical treatment. With the rapid development of global urbanization and industrialization, the existing freshwater resources can no longer meet the needs of social and economic development. The global water shortage problem has attracted much attention. Compared with traditional methods, reverse osmosis has irreplaceable advantages such as no phase change, small footprint, low cost, and no secondary pollution. It has been widely used in pharmaceuticals, food, beverages, alcohol, chemicals, electronics, semiconductors, environmental protection and other fields.

At present, most of the reverse osmosis membranes on the market are aromatic polyamide structure composite membranes. The functional layer is obtained on the surface of the polysulfone-based membrane through the interfacial condensation reaction of m-phenylenediamine and trimesoyl chloride. In the reaction process, there will be residual monomers that have not reacted completely and their decomposition products that need to be removed after the completion of the interfacial polymerization reaction. At the same time, due to the regulation of membrane performance, a series of rinsing with chemicals is required, among which acid rinsing is one of the important processes, thus generating a large amount of acidic wastewater. Since the acidic wastewater is highly acidic with a pH between 1-1.5 and contains organic solvents and aromatic amine compounds, it not only requires a large amount of reagents to neutralize the acid, but also requires a large amount of reagents to neutralize the acid. and acidity, and will also reduce the biological activity of the biochemical system, thereby reducing the ability of the biochemical system to degrade organic matter, and the treatment efficiency is high and the cost is low; the existing technology directly discharges the rinse acid wastewater into the sewage treatment system for neutralization in the regulating tank and then performs biochemical treatment. Since there are a large number of acidic substances in the waste liquid that need to be neutralized by alkaline agents, and it also contains organic solvents and aromatic amine compounds, it will reduce biological activity, thereby reducing the ability of the biochemical system to degrade organic matter. It must be diluted to a certain concentration before biochemical treatment can be carried out. For this reason, we propose a reverse osmosis composite membrane rinse liquid acid recovery system and its recovery method.

Contents of the invention

Technical problem solved: In view of the shortcomings of the existing technology, the present invention provides a reverse osmosis composite membrane rinse liquid acid recovery system and its recovery method. The acidic wastewater is pre-separated with an acid-resistant membrane and reused after separation and purification, which not only reduces It reduces the production cost, reduces the load of sewage treatment, utilizes acid resources, reduces pollution, improves the processing capacity of the biochemical system, and can effectively solve the problems in the background technology.

Technical solution: In order to achieve the above purpose, the technical solution adopted by the present invention is: a reverse osmosis composite membrane rinse liquid acid recovery system, including a rinse tank, a precision filter, a first-level acid-resistant nanofiltration membrane system, and a second-level acid-resistant nanofiltration membrane. System and dosing box, a rinsing liquid delivery pipe is connected between the rinsing tank and the precision filter, a filtrate pipe is connected between the precision filter and the first-level acid-resistant nanofiltration membrane system, and the first-level acid-resistant nanofiltration membrane system A primary water production pipe is connected between the membrane system and the secondary acid-resistant nanofiltration membrane system. A secondary concentrated water pipe is connected between the secondary acid-resistant nanofiltration membrane system and the filtrate pipe. The secondary acid-resistant nanofiltration membrane system is connected to the adding water pipe. A secondary water production pipe is connected between the medicine boxes, the medicine adding box is connected to the position of the rinsing tank, the precision filter outputs impurities to an impurity collection box, and an organic matter buffer tank is connected to the first-level acid-resistant nanofiltration membrane system.

As a preferred technical solution of the present application, the output end of the rinsing tank is connected to the input end of the precision filter through a rinsing liquid delivery pipe, and the output end of the precision filter is connected to the first-level acid-resistant nanofiltration membrane through a filtrate pipe. The input end of the system is connected through, the output end of the first-level acid-resistant nanofiltration membrane system is connected through the first-level water production pipe and the input end of the second-level acid-resistant nanofiltration membrane system, and the output end of the second-level acid-resistant nanofiltration membrane system The secondary water production pipe is connected to the input end of the dosing box, and the output end of the dosing box is connected to the input end of the rinsing tank.

As a preferred technical solution of the present application, several sets of lower film feeding rollers and upper film feeding rollers are respectively installed at the upper and lower positions inside the rinsing tank. The upper film feeding roller is located above the lower film feeding roller. The rinsing tank The upper feeding part is provided with a film feeding roller, and a composite film moves between the film feeding roller, the lower film feeding roller and the upper film feeding roller.

As a preferred technical solution of the present application, the composite film enters from the position of the film feeding roller and performs transportation activities between several sets of lower film feeding rollers and upper film feeding rollers.

As a preferred technical solution of the present application, an upper liquid level monitor, a middle liquid level monitor and a lower liquid level monitor are installed in sequence from top to bottom on the inner wall of the rinsing tank.

As a preferred technical solution of the present application, a driving machine is installed on the top of the dosing box, a stirring shaft is movably arranged at the bottom of the driving machine, a connector is positioned on the stirring shaft, an agitator is positioned on the connector, a connecting frame is positioned on the middle outer wall of the stirring shaft, a cleaning frame is installed on the end of the connecting frame, a cleaning brush is installed on the outer side of the cleaning frame, and a liquid level sensor is installed on the inner wall of the dosing box.

As a preferred technical solution of the present application, the driving machine drives the stirring shaft and drives the connecting frame and the stirrer to rotate, and the connecting frame drives the cleaning frame and the cleaning brush to move, and the cleaning brush contacts the inner wall of the medicine adding box.

A reverse osmosis composite membrane rinse liquid acid recovery method includes the following steps:

S1: Pass the acidic rinse solution of the composite membrane rinse tank through a 5-10um precision filter for primary filtration to remove some mechanical impurities such as debris and particulate matter generated during the membrane production process;

S2: The filtered acidic wastewater enters the first-level acid-resistant nanofiltration membrane system to remove most organic matter;

S3: The first-level produced water enters the second-level acid-resistant nanofiltration membrane system to remove organic matter for a second time, and the second-level concentrated water returns to the first-level;

S4: The secondary produced water enters the dosing box for concentration adjustment;

S5: The concentration is adjusted to the use concentration and enters the composite membrane rinsing tank for recycling.

Beneficial effects: Compared with the prior art, the present invention provides a reverse osmosis composite membrane rinse liquid acid recovery system and its recovery method, which has the following beneficial effects: This reverse osmosis composite membrane rinse liquid acid recovery system and its recovery The method is to pre-separate acidic wastewater with an acid-resistant membrane and reuse it after separation and purification. This not only reduces production costs, but also reduces the load of sewage treatment, utilizes acid resources, reduces pollution, improves the processing capacity of the biochemical system, and rinses the composite membrane. The acidic rinse liquid of the tank is initially filtered through a 5-10um precision filter to remove some mechanical impurities such as debris and particulate matter produced during the membrane production process; the filtered acidic wastewater enters the first-level acid-resistant nanofiltration membrane system to remove most organic matter; the first-level The produced water enters the secondary acid-resistant nanofiltration membrane system for secondary organic matter removal, and the secondary concentrated water returns to the primary level; the secondary produced water enters the dosing tank for concentration adjustment; the concentration is adjusted to the use concentration and enters the composite membrane rinse tank for recycling. The reverse osmosis composite membrane rinse liquid acid recovery system has a simple structure, is easy to operate, and has better results than traditional methods.

Description of the drawings

FIG. 1 is a schematic diagram of the overall structure of a reverse osmosis composite membrane rinse liquid acid recovery system and a recovery method thereof according to the present invention.

FIG. 2 is a schematic structural diagram of an acid-resistant nanofiltration membrane system in a reverse osmosis composite membrane rinse liquid acid recovery system and a recovery method thereof according to the present invention.

Figure 3 is a schematic structural diagram of a rinse tank in a reverse osmosis composite membrane rinse liquid acid recovery system and its recovery method according to the present invention.

Figure 4 is a schematic structural diagram of a chemical dosing box in a reverse osmosis composite membrane rinse liquid acid recovery system and its recovery method according to the present invention.

In the figure: 1. rinsing tank; 2. composite membrane; 3. membrane feed roller; 4. rinsing liquid delivery pipe; 5. impurity collection box; 6. precision filter; 7. filtrate tube; 8. organic matter buffer tank; 9. primary acid-resistant nanofiltration membrane system; 10. primary water production pipe; 11. secondary concentrated water pipe; 12. secondary acid-resistant nanofiltration membrane system; 13. secondary water production pipe; 14. dosing box; 15. upper liquid level monitor; 16. middle liquid level monitor; 17. lower liquid level monitor; 18. stirring shaft; 19. lower film transport roller; 20. stirrer; 21. connector; 22. cleaning rack; 23. upper film transport roller; 24. driving machine; 25. liquid level sensor; 26. cleaning brush; 27. connecting rack.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation modes. However, those skilled in the art will understand that the following described embodiments are some of the embodiments of the present invention, rather than all of them. They are only used to illustrate the invention and should not be construed as limiting the scope of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. If the specific conditions are not specified in the examples, the conditions should be carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional products that can be purchased commercially.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

As shown in Figure 1-4, a reverse osmosis composite membrane rinse liquid acid recovery system includes a rinse tank 1, a precision filter 6, a first-level acid-resistant nanofiltration membrane system 9, a second-level acid-resistant nanofiltration membrane system 12 and dosing Box 14, a rinse liquid delivery pipe 4 is connected between the rinsing tank 1 and the precision filter 6, a filtrate pipe 7 is connected between the precision filter 6 and the first-level acid-resistant nanofiltration membrane system 9, and the first-level acid-resistant nanofiltration membrane system 9 A primary water production pipe 10 is connected to the secondary acid-resistant nanofiltration membrane system 12. A secondary concentrated water pipe 11 is connected between the secondary acid-resistant nanofiltration membrane system 12 and the filtrate pipe 7. The secondary acid-resistant nanofiltration membrane system 12 is connected to the processing A secondary water production pipe 13 is connected between the medicine boxes 14. The medicine dosing box 14 is connected to the position of the rinsing tank 1. The precision filter 6 outputs impurities to the impurity collection box 5. The first-level acid-resistant nanofiltration membrane system 9 is connected to an organic matter buffer tank. 8. Separate the acidic wastewater in advance with an acid-resistant membrane, and reuse it after separation and purification. This not only reduces production costs, but also reduces the load of sewage treatment, utilizes acid resources, reduces pollution, and improves the processing capacity of the biochemical system.

Furthermore, the output end of the rinsing tank 1 is connected to the input end of the precision filter 6 through the rinsing liquid delivery pipe 4, the output end of the precision filter 6 is connected to the input end of the first-level acid-resistant nanofiltration membrane system 9 through the filtrate pipe 7, the output end of the first-level acid-resistant nanofiltration membrane system 9 is connected to the input end of the second-level acid-resistant nanofiltration membrane system 12 through the first-level water production pipe 10, the output end of the second-level acid-resistant nanofiltration membrane system 12 is connected to the input end of the drug dosing box 14 through the second-level water production pipe 13, and the output end of the drug dosing box 14 is connected to the input end of the rinsing tank 1.

Furthermore, several groups of lower film transport rollers 19 and upper film transport rollers 23 are respectively installed at the upper and lower positions inside the rinsing tank 1. The upper film transport roller 23 is located above the lower film transport roller 19. The upper end feeding part of the rinsing tank 1 is provided with a film feed roller 3. A composite film 2 moves between the film feed roller 3, the lower film transport roller 19 and the upper film transport roller 23.

Furthermore, the composite film 2 enters from the film feed roller 3 and is transported between several groups of lower film transport rollers 19 and upper film transport rollers 23 .

Furthermore, an upper liquid level monitor 15 , a middle liquid level monitor 16 and a lower liquid level monitor 17 are installed in sequence from top to bottom on the inner wall of the rinsing tank 1 .

Further, a driver 24 is installed on the top of the dosing box 14, and a stirring shaft 18 is movable at the bottom of the driver 24. A connector 21 is positioned on the stirring shaft 18, and a stirrer 20 is positioned on the connector 21. The stirring shaft 18 A connecting frame 27 is positioned on the middle outer wall. A cleaning frame 22 is installed at the end of the connecting frame 27. A cleaning brush 26 is installed on the outside of the cleaning frame 22. A liquid level sensor 25 is installed on the inner wall of the dosing box 14.

Further, the driver 24 drives the stirring shaft 18 and drives the connecting frame 27 and the agitator 20 to rotate. The connecting frame 27 drives the cleaning frame 22 and the cleaning brush 26 to move. The cleaning brush 26 contacts the inner wall of the dosing box 14 .

A method for recovering acid from a reverse osmosis composite membrane rinse solution comprises the following steps:

S1: Pass the acidic rinse solution of the composite membrane rinse tank through a 5-10um precision filter for primary filtration to remove some mechanical impurities such as debris and particulate matter generated during the membrane production process;

S2: The filtered acidic wastewater enters the first-level acid-resistant nanofiltration membrane system to remove most organic matter;

S3: The first-level produced water enters the second-level acid-resistant nanofiltration membrane system to remove organic matter for a second time, and the second-level concentrated water returns to the first-level;

S4: The secondary produced water enters the dosing box for concentration adjustment;

S5: Adjust the concentration to the usage concentration and enter the composite membrane rinse tank for recycling.

Embodiment 1:

1. The acidic rinse solution in the composite membrane rinse tank has a pH of 1.37, a conductivity of 40500 us/cm, and an organic matter content of 655 mg/l. It is initially filtered through a 5um precision filter to remove some debris, particles and other mechanical impurities generated during the membrane production process;

2. The filtered acidic wastewater enters the first-level acid-resistant nanofiltration membrane system, operating pressure is 15 bar, temperature is 25.9°C, and is subjected to first-level separation. The organic matter content of the first-level concentrated water is 741mg/l, the conductivity is 42700us/cm, and the pH=1.42. The product The water organic matter content is 83mg/L, the conductivity is 34800us/cm, and PH=1.3. From the above data, it can be obtained that the first-level organic matter removal rate is 87.33%;

3. The primary produced water is used as the influent water to enter the secondary acid-resistant nanofiltration membrane system for secondary organic removal. The secondary concentrated water returns to the primary. The secondary influent water quality is much cleaner than the primary influent water. Therefore, under the same conditions, the organic removal rate is higher than that of the primary. The organic permeability of the primary produced water is 12.67%. After the secondary treatment, the organic matter in the produced water is calculated at a removal rate of 87.33%, and the organic matter content is still 1.6%. The organic content is very low and can be directly reused;

4. The secondary produced water enters the dosing box for concentration adjustment;

5. Adjust the concentration to the usage concentration and enter the composite membrane rinse tank for recycling.

Working principle: The invention includes a rinsing tank 1, a composite membrane 2, a film feed roller 3, a rinsing liquid delivery pipe 4, an impurity collection box 5, a precision filter 6, a filtrate pipe 7, an organic matter buffer tank 8, and a first-level acid-resistant nanofiltration membrane. System 9, primary water production pipe 10, secondary concentrated water pipe 11, secondary acid-resistant nanofiltration membrane system 12, secondary water production pipe 13, dosing box 14, upper liquid level monitor 15, middle liquid level monitor 16, lower Liquid level monitor 17, stirring shaft 18, lower film conveying roller 19, agitator 20, connector 21, cleaning frame 22, upper film conveying roller 23, driver 24, liquid level sensor 25, cleaning brush 26 and connecting frame 27 , the acidic wastewater is pre-separated with an acid-resistant membrane, and reused after separation and purification, which not only reduces production costs, but also reduces the load of sewage treatment, utilizes acid resources, reduces pollution, improves the processing capacity of the biochemical system, and uses the composite membrane rinse tank The acidic rinse liquid is initially filtered through a 5-10um precision filter to remove some mechanical impurities such as debris and particulate matter produced during the membrane production process; the filtered acidic wastewater enters the first-level acid-resistant nanofiltration membrane system to remove most organic matter; the first-level product The water enters the secondary acid-resistant nanofiltration membrane system to remove organic matter for a second time, and the secondary concentrated water returns to the primary level; the secondary produced water enters the dosing tank for concentration adjustment; the concentration is adjusted to the use concentration and enters the composite membrane rinse tank for recycling.

It should be noted that in this article, relational terms such as first and second (No. 1, No. 2), etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or sequence between such entities or operations. Furthermore, the terms "comprises," "comprises," or any other variation thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also those not expressly listed other elements, or elements inherent to the process, method, article or equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article, or apparatus that includes the stated element.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions only illustrate the principles of the present invention. The present invention will also have other aspects without departing from the spirit and scope of the present invention. Various changes and modifications are possible, which fall within the scope of the claimed invention.

Claims (8)

1. A reverse osmosis composite membrane rinse liquid acid recovery system, including a rinse tank (1), a precision filter (6), a first-level acid-resistant nanofiltration membrane system (9), a second-level acid-resistant nanofiltration membrane system (12) and Dosing box (14), characterized in that: a rinsing liquid delivery pipe (4) is connected between the rinsing tank (1) and a precision filter (6), and the precision filter (6) is connected to a first-level acid-resistant sodium A filtrate pipe (7) is connected between the filter membrane system (9), and a first-level water production pipe (10) is connected between the first-level acid-resistant nanofiltration membrane system (9) and the second-level acid-resistant nanofiltration membrane system (12). A secondary concentrated water pipe (11) is connected between the secondary acid-resistant nanofiltration membrane system (12) and the filtrate pipe (7), and between the secondary acid-resistant nanofiltration membrane system (12) and the dosing tank (14) There is a secondary water production pipe (13) connected in between, the dosing box (14) is connected to the position of the rinsing tank (1), the precision filter (6) outputs impurities to the impurity collection box (5), the first-level The acid-resistant nanofiltration membrane system (9) is connected with an organic matter buffer tank (8). 2. A reverse osmosis composite membrane rinse liquid acid recovery system according to claim 1, characterized in that: the output end of the rinse tank (1) passes through a rinse liquid delivery pipe (4) and a precision filter (6) The input end of the precision filter (6) is connected through the filtrate pipe (7) with the input end of the first-level acid-resistant nanofiltration membrane system (9). The first-level acid-resistant nanofiltration membrane system (9) The output end of 9) is connected through the primary water production pipe (10) to the input end of the secondary acid-resistant nanofiltration membrane system (12), and the output end of the secondary acid-resistant nanofiltration membrane system (12) passes through the secondary water production pipe. (13) is connected throughly with the input end of the chemical dosing box (14), and the output end of the chemical dosing box (14) is connected throughly with the input end of the rinsing tank (1). 3. A reverse osmosis composite membrane rinsing liquid acid recovery system according to claim 1, characterized in that: a plurality of groups of lower membrane transport rollers (19) and upper membrane transport rollers (23) are respectively installed at upper and lower positions inside the rinsing tank (1), and the upper membrane transport roller (23) is located above the lower membrane transport roller (19); a membrane feed roller (3) is provided at the upper feeding part of the rinsing tank (1), and a composite membrane (2) is movable between the membrane feed roller (3), the lower membrane transport roller (19) and the upper membrane transport roller (23). 4. A reverse osmosis composite membrane rinse liquid acid recovery system according to claim 3, characterized in that: the composite membrane (2) enters from the position of the film feeding roller (3) and is transported under several groups of film feeding rollers. The conveying activity is carried out between (19) and the upper film conveying roller (23). 5. A reverse osmosis composite membrane rinse liquid acid recovery system according to claim 1, characterized in that: upper liquid level monitors (15) are installed on the inner wall of the rinse tank (1) from top to bottom. ), middle liquid level monitor (16) and lower liquid level monitor (17). 6. A reverse osmosis composite membrane rinse liquid acid recovery system according to claim 1, characterized in that: a driver (24) is installed on the top of the dosing box (14), and the driver (24) A stirring shaft (18) is movable at the bottom of the stirring shaft (18). A connector (21) is positioned on the stirring shaft (18). A stirrer (20) is positioned on the connector (21). The stirring shaft (18) A connecting frame (27) is positioned on the outer wall of the middle part. A cleaning frame (22) is installed at the end of the connecting frame (27). A cleaning brush (26) is installed on the outside of the cleaning frame (22). The dosing box A liquid level sensor (25) is installed on the inner wall of (14). 7. A reverse osmosis composite membrane rinse liquid acid recovery system according to claim 6, characterized in that: the driver (24) drives the stirring shaft (18) and drives the connecting frame (27) and the stirrer (20) ) rotates, and the connecting frame (27) drives the cleaning frame (22) and the cleaning brush (26) to move, and the cleaning brush (26) contacts the inner wall of the dosing box (14). 8. A reverse osmosis composite membrane rinse liquid acid recovery method, characterized by: including the following steps: S1: Pass the acidic rinse solution of the composite membrane rinse tank through a 5-10um precision filter for primary filtration to remove some mechanical impurities such as debris and particulate matter generated during the membrane production process; S2: The filtered acidic wastewater enters the first-level acid-resistant nanofiltration membrane system to remove most organic matter; S3: The primary produced water enters the secondary acid-resistant nanofiltration membrane system for secondary organic removal, and the secondary concentrated water returns to the primary; S4: The secondary produced water enters the dosing box for concentration adjustment; S5: Adjust the concentration to the usage concentration and enter the composite membrane rinse tank for recycling.