A water treatment system

Abstract

The utility model discloses a water treatment system in the field of water treatment, aims at solving the technical problem of reverse osmosis membrane scale, block, system cannot stable operation. The system includes: primary pretreatment unit, primary ultrafiltration device, primary reverse osmosis device, secondary pretreatment unit, secondary ultrafiltration device, secondary reverse osmosis device and tertiary reverse osmosis device, the primary pretreatment unit water connection primary ultrafiltration device water intake, primary ultrafiltration device water access primary reverse osmosis device, primary reverse osmosis device concentrated water end connects secondary pretreatment unit, and the secondary pretreatment unit water is through secondary ultrafiltration device, and the secondary ultrafiltration water end access secondary reverse osmosis device, and its concentrated water finally enters tertiary reverse osmosis device. The utility model can combine and handle the circulating water drainage and the sewage collected in factory area, to realize water resource recovery and minimum wastewater discharge.

Description

Technical Field

[0001] This utility model relates to a water treatment system and belongs to the field of wastewater treatment technology. Background Technology

[0002] In industrial production processes, circulating water is often used to cool materials through heat exchangers or coolers. To prevent scaling on heat exchange equipment, the concentration ratio of the circulating water needs to be controlled. This means that a portion of the circulating water, which has higher salinity and hardness than fresh water, must be periodically discharged and replenished with fresh water. The circulating water wastewater generated in this process has high salt content, high hardness, high silicon content, and high COD (impurities and organic matter), and direct discharge would result in water waste. Currently, there is a lack of mature, reliable, and cost-effective solutions for achieving low discharge in circulating water systems within the industry. The main technical challenges lie in the efficient hardness and silicon removal process in the pretreatment stage, which requires precise control of pH value and chemical dosage. Simultaneously, the subsequent reverse osmosis system faces high-pressure operating conditions for treating high-salinity feed water, placing stringent requirements on membrane materials and chemical cleaning procedures. Therefore, there is an urgent need to develop an integrated water treatment system that can treat circulating water wastewater and collected wastewater from the plant simultaneously, achieving efficient water resource recovery and low wastewater discharge. Utility Model Content

[0003] The purpose of this invention is to provide a water treatment system that can treat wastewater and circulating water discharged from the production area in a unified manner, thereby improving the efficiency of water resource utilization.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution.

[0005] On the one hand, this utility model provides a water treatment system, including a primary pretreatment unit, a primary ultrafiltration membrane device, a primary reverse osmosis device, a secondary pretreatment unit, a secondary ultrafiltration membrane device, a secondary reverse osmosis device, and a tertiary reverse osmosis device; The secondary pretreatment unit includes a secondary high-efficiency sedimentation tank, a secondary multi-media filter, and a secondary self-cleaning filter; The outlet of the primary pretreatment unit is connected to the inlet of the primary ultrafiltration membrane device, and the outlet of the primary ultrafiltration device is connected to the inlet of the primary reverse osmosis device. The outlet of the first-stage reverse osmosis unit is connected to the second-stage high-efficiency sedimentation tank. The outlet of the second-stage high-efficiency sedimentation tank is connected to the inlet of the second-stage multi-media filter. The outlet of the second-stage multi-media filter is connected to the inlet of the second-stage self-cleaning filter. The outlet of the second-stage self-cleaning filter is connected to the inlet of the second-stage ultrafiltration unit. The outlet of the second-stage ultrafiltration unit is connected to the inlet of the second-stage reverse osmosis unit. The outlet of the second-stage reverse osmosis unit is connected to the inlet of the third-stage reverse osmosis unit.

[0006] Preferably, the primary pretreatment unit includes a wastewater tank, a circulating water drainage tank, a primary high-efficiency sedimentation tank, a pH adjustment tank, an ozone reaction tank, a primary multi-media filter, and a primary self-cleaning filter connected in sequence. Preferably, the outlet of the primary self-cleaning filter is connected to the inlet of the secondary high-efficiency sedimentation tank.

[0007] Preferably, the primary pretreatment unit further includes a sludge system and a sludge drying system, wherein the sludge system is connected to the primary high-efficiency sedimentation tank, and the sludge drying system is connected to the sludge system.

[0008] Preferably, the product water outlets of the first-stage reverse osmosis unit, the second-stage reverse osmosis unit, and the third-stage reverse osmosis unit are all connected to the recycled water tank.

[0009] Preferably, the primary multi-media filter, the primary self-cleaning filter, the secondary multi-media filter, and the secondary self-cleaning filter are backwashed using water from the recycled water tank, and the water in the recycled water tank originates from the product water of the primary reverse osmosis unit, the secondary reverse osmosis unit, and the tertiary reverse osmosis unit.

[0010] Preferably, the primary, secondary, and tertiary reverse osmosis units utilize water from the recycled water tank for backwashing and chemical cleaning, and the resulting wastewater is returned to the wastewater pool.

[0011] Preferably, both the primary high-efficiency sedimentation tank and the secondary high-efficiency sedimentation tank are provided with sludge discharge outlets at the bottom, and sludge pumps are provided at the sludge discharge outlets to transport the sludge collected at the bottom of the primary and secondary high-efficiency sedimentation tanks to the sludge system.

[0012] Preferably, the outlet of the three-stage reverse osmosis device is connected to the concentrate tank.

[0013] Compared with the prior art, the beneficial effects achieved by this utility model are as follows: This invention effectively reduces the treatment load and pollution risk of subsequent membrane systems by passing collected wastewater and circulating water through a primary and secondary pretreatment unit. Since the collected wastewater and circulating water discharge undergo no pretreatment, the primary pretreatment involves pH adjustment in a pH adjustment tank after a primary high-efficiency sedimentation tank, followed by ozonation sterilization and COD (impurities and organic matter) degradation in an ozone reaction tank. This is followed by a primary multi-media filtration system and a primary self-cleaning filtration system for guaranteed filtration. The effluent from the primary pretreatment then enters a primary ultrafiltration unit via a primary self-cleaning filter to further remove fine particles. The permeate then enters a primary reverse osmosis unit for deep desalination. Because the primary pretreatment performs pH adjustment and ozonation sterilization and COD degradation, the concentrate produced by the primary reverse osmosis unit does not require further pH adjustment and ozonation sterilization. The secondary pretreatment simplifies the pH adjustment and ozonation sterilization steps, thus optimizing the system. This integrated design, through process optimization, reduces costs while improving the efficiency of desalination, hardness removal, and silica removal, and enhances the system's anti-fouling capabilities. This significantly reduces the risk of reverse osmosis membrane scaling, decreases the frequency of chemical cleaning, and ultimately achieves stable operation with a system water recovery rate exceeding 95% and excellent product water quality. It provides a reliable solution for the utilization and low emission of water resources with high salinity, high hardness, high silica content, and high COD. Attached Figure Description

[0014] Figure 1 The diagram shown is a partial structural schematic of the primary preprocessing unit provided by this utility model. Figure 2 The diagram shown is a schematic diagram of the primary preprocessing unit structure provided by this utility model; Figure 3 The diagram shown is a structural schematic of a water treatment system provided by this utility model; Figure 4 The diagram shown is a schematic diagram of the two-stage preprocessing unit provided by this utility model; In the diagram, 1. Primary pretreatment unit; 101. Wastewater tank; 102. Circulating water drainage tank; 103. Primary high-efficiency sedimentation tank; 104. pH adjustment tank; 105. Ozone reaction tank; 106. Primary multi-media filter; 107. Primary self-cleaning filter; 2. Secondary pretreatment unit; 201. Secondary high-efficiency sedimentation tank; 202. Secondary multi-media filter; 203. Secondary self-cleaning filter; 3. Primary ultrafiltration membrane device; 4. Primary reverse osmosis device; 5. Secondary ultrafiltration membrane device; 6. Secondary reverse osmosis device; 7. Tertiary reverse osmosis device; 8. Reclaimed water tank; 9. Concentrate tank; 10. Sludge system; 11. Sludge drying treatment system. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0016] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example 1

[0018] See Figure 1 and Figure 3 This embodiment introduces a water treatment system that, through its primary pretreatment unit 1, primary ultrafiltration device 3, primary reverse osmosis device 4, secondary pretreatment unit 2, secondary ultrafiltration device 5, secondary reverse osmosis device 6, and tertiary reverse osmosis device 7, achieves efficient purification and resource utilization of circulating water and wastewater with high impurity content.

[0019] The system first performs advanced treatment on the collected wastewater through pretreatment unit 1. Specifically, the effluent of the first-stage pretreatment unit 1 is connected to the influent of the first-stage ultrafiltration membrane device 3, and the effluent of the first-stage ultrafiltration membrane device 3 is connected to the influent of the first-stage reverse osmosis device 4.

[0020] See Figure 4The secondary pretreatment unit 2 includes a secondary high-efficiency sedimentation tank 201, a secondary multi-media filter 202, and a secondary self-cleaning filter 203. The outlet of the primary reverse osmosis unit 4 is connected to the secondary high-efficiency sedimentation tank 201; the outlet of the secondary high-efficiency sedimentation tank 201 is connected to the inlet of the secondary multi-media filter 202; the outlet of the secondary multi-media filter 202 is connected to the inlet of the secondary self-cleaning filter 203; the outlet of the secondary self-cleaning filter 203 is connected to the inlet of the secondary ultrafiltration unit 5; the outlet of the secondary ultrafiltration unit 5 is connected to the inlet of the secondary reverse osmosis unit 6; the outlet of the secondary reverse osmosis unit 6 is connected to the inlet of the tertiary reverse osmosis unit 7; and the outlet of the tertiary reverse osmosis unit 7 is connected to the concentrate tank 9.

[0021] This second pretreatment process involves efficient sedimentation in the primary pretreatment unit 1, followed by pH adjustment and ozonation sterilization to degrade COD. This removes most of the hardness, silica, suspended solids, and some COD, providing qualified feed water for the subsequent primary ultrafiltration membrane unit 3 and primary reverse osmosis unit 4. Since the primary pretreatment unit 1 performs pH adjustment and ozonation sterilization to degrade COD, the concentrate produced by the primary reverse osmosis unit 4 does not require further pH adjustment or ozonation sterilization. The secondary pretreatment unit 2, after efficient sedimentation in the primary pretreatment unit 1, directly passes through the secondary multi-media filter 202 and the secondary self-cleaning filter 203 to remove fine particles, simplifying the pH adjustment and ozonation sterilization steps and optimizing the system.

[0022] Finally, the water then undergoes fine filtration through an ultrafiltration membrane device (secondary ultrafiltration membrane device 5) and efficient desalination through two reverse osmosis devices (secondary reverse osmosis device 6 and tertiary reverse osmosis device 7), further ensuring the long-term stable operation and high recovery rate of the system, and ultimately achieving efficient recycling of water resources. Example 2

[0023] See Figure 1 Starting from wastewater tank 101, a circulating water drainage tank 102, a primary high-efficiency sedimentation tank 103, a pH adjustment tank 104, an ozone reaction tank 105, a primary multi-media filter 106, and a primary self-cleaning filter 107 are connected in sequence, forming a complete first pretreatment process.

[0024] See Figure 2 The first pretreatment unit 1 also includes a sludge system 10 and a sludge drying treatment system 11. The sludge system 10 is connected to the primary high-efficiency sedimentation tank 103, and the sludge drying treatment system 11 is connected to the sludge system 10. It is used to treat the sludge generated during the sedimentation process in a timely manner and ensure the continuous and stable operation of the pretreatment process.

[0025] In this embodiment of the utility model, the reverse osmosis device adopts a multi-stage series design, including a first-stage reverse osmosis device 4, a second-stage reverse osmosis device 6, and a third-stage reverse osmosis device 7. The product water outlet of the first-stage ultrafiltration membrane device 3 is connected to the inlet of the first-stage reverse osmosis device 4, the outlet of the first-stage reverse osmosis device 4 is connected to the inlet of the second-stage reverse osmosis device 6, and the outlet of the second-stage reverse osmosis device 6 is connected to the inlet of the third-stage reverse osmosis device 7. Furthermore, the first-stage reverse osmosis device 4, the second-stage reverse osmosis device 6, and the third-stage reverse osmosis device 7 are all connected to a recycling tank 8 to collect and reuse the product water from each stage of the reverse osmosis device.

[0026] In the actual process of progressive concentration and deep desalination, the collected wastewater and circulating water drainage are treated by the primary pretreatment unit 1 and then sent to the primary ultrafiltration membrane device 3 for further treatment. The permeate then enters the primary reverse osmosis device 4 for preliminary desalination. At this stage, about 75% of the permeate can be recovered, and the remaining 25% becomes primary concentrate and enters the secondary pretreatment unit 2 for further treatment.

[0027] The secondary pretreatment unit 2 is located before the secondary ultrafiltration membrane device 5 and includes a secondary high-efficiency sedimentation tank 201, a secondary multi-media filter 202 and a secondary self-cleaning filter 203 connected in sequence. It is used to remove hardness, silica and filter the concentrated water and remove small particles.

[0028] The primary concentrate from the secondary pretreatment unit 2 enters the secondary ultrafiltration membrane unit 5 and the secondary reverse osmosis unit 6 for further treatment. After treatment in the secondary reverse osmosis unit, approximately 70% of the freshwater in the primary concentrate enters the reuse tank 8 for reuse, while approximately 30% becomes secondary concentrate and enters the tertiary reverse osmosis unit for treatment. In the tertiary reverse osmosis unit, approximately one-third of the secondary concentrate can be recovered, resulting in a final overall system recovery rate of 95% or higher. The tertiary concentrate produced by the tertiary reverse osmosis unit accounts for approximately two-thirds of the secondary concentrate (approximately 3-5% of the total influent of the water treatment system in this application). After being collected in a concentrate tank, the tertiary concentrate can be used for spray dust removal and impurity removal, achieving comprehensive utilization of wastewater throughout the entire process.

[0029] In addition, to improve the economic efficiency of system operation, the primary multi-media filter 106, the primary self-cleaning filter 107, the secondary multi-media filter 202 and the secondary self-cleaning filter 203 use water from the recycled water tank 8 for backwashing, thereby reducing the consumption of external clean water. The water in the recycled water tank 8 comes from the product water of the primary reverse osmosis device 4, the secondary reverse osmosis device 6 and the tertiary reverse osmosis device 7.

[0030] In a further embodiment of this invention, the primary reverse osmosis unit 4, the secondary reverse osmosis unit 6, and the tertiary reverse osmosis unit 7 utilize water from the return water tank 5 for backwashing and chemical cleaning, and return the generated wastewater to the wastewater pool 101, thereby achieving internal circulation of the cleaning wastewater. The final total system recovery rate can reach 95%-97%, while the tertiary concentrate produced by the tertiary reverse osmosis (accounting for approximately 3-5% of the total system feed water) can be used for spray dust removal and impurity removal.

[0031] In a further embodiment of this utility model, both the primary high-efficiency sedimentation tank 103 and the secondary high-efficiency sedimentation tank 201 are equipped with sludge discharge outlets at their bottoms. A sludge pump is installed at each sludge discharge outlet, and the sludge pump transports the sludge collected at the bottom of the primary high-efficiency sedimentation tank 103 and the secondary high-efficiency sedimentation tank 201 to the sludge system 10. Specifically, the secondary high-efficiency sedimentation tank 103 is equipped with a mechanical agitator and scraper at its bottom. This mechanical agitator and scraper collects the flocculated sludge at the bottom of the sedimentation tank and transports it to the sludge system 10 and the sludge drying treatment system 11 via the sludge pump, thereby achieving centralized sludge treatment. Finally, after deep treatment by this water treatment system, the water quality in the recycled water tank 8 can reach the following high standards: Chemical Oxygen Demand (CODCr) ≤ 10 mg / L, pH value stable between 7.0 and 8.0, total hardness ≤ 3 mmol / L, chloride ion (… Content ≤80mg / L.

[0032] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A water treatment system, characterized in that, It includes a primary pretreatment unit (1), a primary ultrafiltration membrane device (3), a primary reverse osmosis device (4), a secondary pretreatment unit (2), a secondary ultrafiltration membrane device (5), a secondary reverse osmosis device (6), and a tertiary reverse osmosis device (7). The outlet of the first-stage pretreatment unit (1) is connected to the inlet of the first-stage ultrafiltration membrane device (3), and the outlet of the first-stage ultrafiltration device (3) is connected to the inlet of the first-stage reverse osmosis device (4). The secondary pretreatment unit (2) includes: a secondary high-efficiency sedimentation tank (201), a secondary multi-media filter (202), and a secondary self-cleaning filter (203); The outlet of the primary reverse osmosis device (4) is connected to the secondary high-efficiency sedimentation tank (201). The outlet of the secondary high-efficiency sedimentation tank (201) is connected to the inlet of the secondary multi-media filter (202). The outlet of the secondary multi-media filter (202) is connected to the inlet of the secondary self-cleaning filter (203). The outlet of the secondary self-cleaning filter (203) is connected to the inlet of the secondary ultrafiltration device (5). The outlet of the secondary ultrafiltration device (5) is connected to the inlet of the secondary reverse osmosis device (6). The outlet of the secondary reverse osmosis device (6) is connected to the inlet of the tertiary reverse osmosis device (7).

2. The water treatment system according to claim 1, characterized in that, The primary pretreatment unit (1) includes a wastewater tank (101), a circulating water drainage tank (102), a primary high-efficiency sedimentation tank (103), a pH adjustment tank (104), an ozone reaction tank (105), a primary multi-media filter (106), and a primary self-cleaning filter (107) connected in sequence.

3. The water treatment system according to claim 2, characterized in that, The outlet of the primary self-cleaning filter (107) is connected to the inlet of the secondary high-efficiency sedimentation tank (201).

4. The water treatment system according to claim 2, characterized in that, The primary pretreatment unit (1) further includes a sludge system (10) and a sludge drying treatment system (11). The sludge system (10) is connected to the primary high-efficiency sedimentation tank (103), and the sludge drying treatment system (11) is connected to the sludge system (10).

5. The water treatment system according to claim 2, characterized in that, The product water outlets of the first-stage reverse osmosis unit (4), the second-stage reverse osmosis unit (6), and the third-stage reverse osmosis unit (7) are all connected to the recycled water tank (8).

6. The water treatment system according to claim 5, characterized in that, The primary multi-media filter (106), the primary self-cleaning filter (107), the secondary multi-media filter (202), and the secondary self-cleaning filter (203) use water from the recycled water tank (8) for backwashing, and the water in the recycled water tank (8) comes from the product water of the primary reverse osmosis device (4), the secondary reverse osmosis device (6), and the tertiary reverse osmosis device (7).

7. The water treatment system according to claim 6, characterized in that, The primary reverse osmosis unit (4), the secondary reverse osmosis unit (6) and the tertiary reverse osmosis unit (7) use water in the recycled water tank (8) for backwashing and chemical cleaning, and the wastewater generated is returned to the wastewater pool (101).

8. The water treatment system according to claim 4, characterized in that, Both the primary high-efficiency sedimentation tank (103) and the secondary high-efficiency sedimentation tank (201) are equipped with sludge discharge outlets at the bottom. A sludge pump is installed at the sludge discharge outlets, and the sludge pump transports the sludge collected at the bottom of the primary high-efficiency sedimentation tank (103) and the secondary high-efficiency sedimentation tank (201) to the sludge system (10).

9. The water treatment system according to claim 1, characterized in that, The outlet of the three-stage reverse osmosis device (7) is connected to the concentrate tank (9).

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