Underground water treatment system

Abstract

Belonging to the technical field of underground water treatment, the invention provides an underground water treatment system, which comprises a raw water tank, a security filter, an ultrafiltration membrane assembly, an intermediate water tank, an ozone treatment device and a water production tank. An outlet of the raw water tank is communicated with an inlet of the main pipeline, and an outlet end of the main pipeline is communicated with the water producing tank; a security filter, an ultrafiltration membrane assembly, a middle water tank and an ozone treatment device are sequentially communicated from the inlet end to the outlet end of the main pipeline. Polluted groundwater is fed into the security filter through the high-pressure pump, suspended particles in the water are preliminarily removed, then the water enters the ultrafiltration membrane assembly for secondary filtration, macromolecular organic pollutants such as petroleum are further removed, the chemical oxygen demand of the polluted groundwater is greatly reduced, and the water subjected to secondary filtration flows into the middle water tank to be recycled. And further removing soluble organic matters in subsequent oxidation treatment.

Description

Technical Field

[0001] This invention belongs to the field of groundwater treatment technology, and specifically relates to a groundwater treatment system. Background Technology

[0002] With the development of the petrochemical industry, toxic and harmful substances such as petroleum hydrocarbons, benzene compounds, polycyclic aromatic hydrocarbons, and halogenated hydrocarbons in refining waste dumps and oil depots can easily cause groundwater pollution, posing a significant threat to groundwater safety and ecological health. Given that groundwater pollution at these types of sites is usually quite severe, in-situ remediation technologies cannot achieve ideal treatment results, necessitating the extraction and subsequent treatment of the contaminated groundwater.

[0003] Due to the unstable volume of groundwater at contaminated sites, the complex composition of pollutants, and their high toxicity, bioremediation faces significant challenges, inhibiting microbial activity and making stable operation of biological treatment technologies difficult. Current physical adsorption remediation technologies suffer from limitations such as limited adsorption capacity, high operating costs, complex adsorbent regeneration processes, and secondary pollution from discarded adsorbents. Fenton chemical oxidation remediation technology generates large amounts of harmful sludge, significantly increasing treatment costs and also causing secondary pollution. In summary, current biological treatment technologies struggle to achieve stable and efficient treatment of contaminated groundwater; the applied physicochemical technologies generally cause secondary pollution and have high treatment costs. Therefore, innovative upgrades to groundwater extraction and treatment technologies for contaminated sites are urgently needed to address these issues. Summary of the Invention

[0004] To address the above problems, this invention proposes a groundwater treatment system, comprising a raw water tank, a security filter, an ultrafiltration membrane module, an intermediate water tank, an ozone treatment device, and a product water tank.

[0005] The outlet of the raw water tank is connected to the inlet of the main pipeline, and the outlet of the main pipeline is connected to the product water tank; from the inlet to the outlet of the main pipeline, a security filter, an ultrafiltration membrane module, an intermediate water tank, and an ozone treatment device are connected in sequence.

[0006] Furthermore, the ultrafiltration membrane module includes a first check valve, an inlet water flow sensor, an inlet water pressure sensor, a product water flow sensor, a product water pressure sensor, and a membrane product water control valve;

[0007] A first check valve, an inlet flow sensor, and an inlet pressure sensor are sequentially installed on the main pipeline between the security filter and the ultrafiltration membrane assembly.

[0008] A product water flow sensor, a product water pressure sensor, and a membrane product water control valve are sequentially installed on the main pipeline between the product water outlet and the intermediate water tank of the ultrafiltration membrane module.

[0009] The first outlet of the ultrafiltration membrane module is connected to the inlet of the circulation pipe, and the outlet of the circulation pipe is connected to the main pipeline between the first check valve and the inlet flow sensor.

[0010] Furthermore, a reflux control valve, a first flow sensor, a circulation pump, and a second check valve are sequentially connected to the circulation pipeline.

[0011] Furthermore, the ultrafiltration membrane assembly employs multiple sets of ceramic membranes arranged in parallel.

[0012] Furthermore, the ozone treatment device includes an ozone catalytic device;

[0013] The ozone catalytic device is provided with an inlet end and an outlet end, which are connected to the main pipeline.

[0014] An ozone aeration device is installed at the bottom of the ozone catalytic device, and the inlet of the ozone aeration device passes through the ozone catalytic device and is connected to the outlet end of the ozone delivery pipeline; an ozone catalyst is installed inside the ozone catalytic device.

[0015] Furthermore, the ozone catalyst is an aluminum-based or iron-based supported solid catalyst.

[0016] Furthermore, the inlet end of the ozone delivery pipeline is connected to an oxygen cylinder, and an ozone generator, an ozone detector, and a fourth check valve are sequentially installed on the ozone delivery pipeline.

[0017] Furthermore, the ozone treatment device also includes an exhaust gas discharge pipe and a tail gas treatment device, wherein the tail gas treatment device is connected to the exhaust gas outlet of the ozone catalytic device through the exhaust gas discharge pipe.

[0018] Furthermore, the system also includes an ultrafiltration membrane cleaning system, which includes a cleaning water tank;

[0019] A heater is provided on the bottom surface inside the cleaning water tank; the first outlet of the cleaning water tank is connected to the inlet end of the second cleaning pipe, and the outlet end of the second cleaning pipe is connected to the main pipeline between the first check valve and the inlet flow sensor; a cleaning valve, a cleaning pump and a third check valve are sequentially arranged on the second cleaning pipe.

[0020] The first inlet of the cleaning water tank is connected to the cleaning fluid return pipe, and the inlet end of the cleaning fluid return pipe is connected to the main pipeline between the permeate pressure sensor and the membrane permeate control valve.

[0021] Furthermore, the ultrafiltration membrane cleaning system also includes a cleaning liquid discharge pipe, a cleaning water tank discharge valve, and a discharge pump. The cleaning liquid discharge pipe is connected to the second outlet of the cleaning water tank, and the outlet of the cleaning liquid discharge pipe is connected to the raw water tank. The cleaning water tank discharge valve and the discharge pump are sequentially installed on the cleaning liquid discharge pipe.

[0022] Furthermore, the ultrafiltration membrane cleaning system also includes a dosing tank, which is connected to the cleaning water tank via a dosing pipe, and a metering pump and a flow control valve are sequentially installed on the dosing pipe.

[0023] Furthermore, the ultrafiltration membrane cleaning system also includes a cleaning water supply valve and a cleaning water supply pump.

[0024] The cleaning water supply valve and the cleaning water supply pump are connected in sequence to the first cleaning pipe. The inlet end of the first cleaning pipe is connected to the product water tank, and the outlet end of the first cleaning pipe is connected to the second injection port of the cleaning water tank.

[0025] Furthermore, an electrically controlled valve and a high-pressure pump are sequentially connected on the main pipeline between the raw water tank and the security filter.

[0026] Furthermore, the system also includes an inlet regulating valve and a first inlet pump; the inlet regulating valve and the first inlet pump are sequentially connected to the main pipeline between the intermediate water tank and the ozone catalytic device.

[0027] Beneficial effects:

[0028] 1. In this invention, polluted groundwater is pumped into a security filter via a high-pressure pump to initially remove suspended particles from the water. Then, it enters an ultrafiltration membrane module for secondary filtration to further remove large molecular organic pollutants such as petroleum, significantly reducing the chemical oxygen demand (COD) of the polluted groundwater. The water after secondary filtration flows into an intermediate water tank for subsequent oxidation treatment to further remove dissolved organic matter.

[0029] 2. This invention includes an ultrafiltration membrane cleaning system. When the ultrafiltration membrane module intercepts a large amount of particulate matter and organic pollutants, its filtration performance will decrease. At this time, the ultrafiltration membrane cleaning system is turned on, and the cleaning pump is used to pump water from the cleaning tank into the cleaning pipeline. After cleaning the ultrafiltration membrane, the water is returned to the cleaning tank through the cleaning return pipeline. This process is repeated to clean the ultrafiltration membrane module, preventing blockage inside the ultrafiltration membrane module and affecting the permeability of polluted groundwater.

[0030] 3. The ultrafiltration membrane module of the present invention adopts multiple sets of parallel-connected polyceramic membranes. Polyceramic membranes have the characteristics of super-hydrophilic and oleophobic surface, fouling resistance, and easy cleaning. They also have the advantages of low pressure drop in the direct current channel, tolerance to high suspended solids and high oil content wastewater, high filtration accuracy, concentrated pore size distribution, and low tendency to cause deep fouling. The ultrafiltration membrane module can be cleaned efficiently and quickly using either permeate water or chemical cleaning agents.

[0031] 4. The ozone catalytic device of the present invention is filled with an aluminum-based or iron-based supported solid catalyst, which has the advantages of high stability, strong ozone mass transfer capacity and high hydroxyl radical yield.

[0032] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of a groundwater treatment system according to an embodiment of the present invention is shown.

[0035] Figure 2 A partial schematic diagram of the groundwater treatment system in an embodiment of the present invention is shown.

[0036] In the diagram, 1. Inlet valve; 2. Raw water tank; 3. Electrically controlled valve; 4. High-pressure pump; 5. Security filter; 6. Ultrafiltration membrane module; 7. Circulation pump; 8. Cleaning pump; 9. Cleaning valve; 10. Cleaning water tank; 11. Flow control valve; 12. Metering pump; 13. Chemical dosing tank; 14. Discharge pump; 15. Oxygen cylinder; 16. Ozone generator; 17. Intermediate water tank; 18. Ozone detector; 19. Inlet regulating valve; 20. Fourth check valve; 21. First inlet pump; 22. Ozone aeration device; 23. Ozone catalytic device; 24. Ozone catalyst; 25. 26. Cleaning water supply pump; 27. Cleaning water supply valve; 28. Product water tank; 29. ​​Tail gas treatment device; 30. Product water discharge valve; 31. External discharge pump; 32. Third check valve; 33. First check valve; 34. Inlet water flow sensor; 35. Inlet water pressure sensor; 36. Second check valve; 37. First flow sensor; 38. Recirculation control valve; 39. Product water flow sensor; 40. Product water pressure sensor; 41. Cleaning recirculation valve; 42. Membrane product water control valve; 43. Agitator; 44. Heater; 45. Cleaning water tank discharge valve; 46. Liquid level sensor;

[0037] 100. Main pipeline; 110. Circulation pipeline; 121. Ozone delivery pipeline; 122. Exhaust gas discharge pipeline;

[0038] 131. First cleaning pipeline; 132. Cleaning fluid return pipeline; 133. Second cleaning pipeline; 134. Cleaning fluid discharge pipeline; 135. Chemical dosing pipeline. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] refer to Figure 1 , Figure 1 A schematic diagram of a groundwater treatment system according to an embodiment of the present invention is shown. Figure 1 As shown, a groundwater treatment system includes a raw water tank 2, a security filter 5, an ultrafiltration membrane module 6, an intermediate water tank 17, an ozone treatment device, a product water tank 27, and a main pipeline 100. The inlet end of the main pipeline 100 is connected to the raw water tank 2, and the outlet end of the main pipeline 100 is connected to the product water tank 27. The security filter 5, the ultrafiltration membrane module 6, the intermediate water tank 17, and the ozone treatment device are sequentially connected from the inlet end to the outlet end of the main pipeline 100. The security filter 5 is used to remove suspended particulate matter in polluted groundwater to protect the ultrafiltration membrane module 6. The ultrafiltration membrane module 6 is used to remove petroleum-based substances and large molecular organic matter from the water. The ultrafiltration membrane module 6 has a product water outlet and a concentrate outlet at its rear end. The product water outlet is connected to the intermediate water tank 17 via a main pipeline 100. A membrane product water control valve 41 is installed on the main pipeline 100 connecting the product water outlet and the intermediate water tank 17. The effluent from the product water side of the ultrafiltration membrane module 6 enters the intermediate water tank 17 for further treatment. The first outlet is the concentrate outlet, which is connected to the inlet of the ultrafiltration membrane module 6 via a circulation pipeline 110. The ozone treatment device is used to reduce the content of organic pollutants in polluted groundwater. An electrically controlled valve 3 and a high-pressure pump 4 are sequentially installed on the main pipeline 100 between the raw water tank 2 and the security filter 5. The electrically controlled valve 3 is located closer to the raw water tank 2. The high-pressure pump 4 pumps the wastewater from the raw water tank 2 into the security filter 5. A product water discharge valve 29 and an external discharge pump 30 are installed on the discharge pipeline of the product water tank 27; the product water discharge valve 29 is located near the product water tank 27. The product water tank 27 discharges or reuses the treated groundwater through the discharge pipeline.

[0041] Raw water tank 2 is used to receive polluted groundwater to be treated. The inlet pipe of raw water tank 2 is connected to the extraction system through inlet valve 1.

[0042] Specifically, a liquid level sensor 45 is installed in the intermediate water tank 17. The liquid level sensor 45 is used to monitor the liquid level in the intermediate water tank 17. The liquid level sensor 45 is linked with the high pressure pump 4 and the inlet water control valve 3. When the liquid level sensor 45 detects that the water level is higher than a certain value, it controls the inlet water control valve 3 to close and the high pressure pump 4 to automatically shut down. When the liquid level sensor 45 detects that the water level is lower than a certain value, it controls the inlet water control valve 3 to open and the high pressure pump 4 to start inputting raw water.

[0043] In the above embodiments, another optional implementation is as follows: a first check valve 32, an inlet flow sensor 33, and an inlet pressure sensor 34 are sequentially installed on the main pipeline 100 between the security filter 5 and the ultrafiltration membrane module 6. The first check valve 32 is located near the security filter 5; the inlet flow sensor 33 is used to monitor the inlet flow rate; and the inlet pressure sensor 34 is used to monitor the inlet pressure. A permeate flow sensor 38, a permeate pressure sensor 39, and a membrane permeate control valve 41 are sequentially installed on the main pipeline 100 between the ultrafiltration membrane module 6 and the intermediate water tank 17. The permeate flow sensor 38 is located near the ultrafiltration membrane module 6; the permeate flow sensor 38 is used to monitor the permeate flow rate of the ultrafiltration membrane module 6; and the permeate pressure sensor 39 is used to monitor the permeate pressure of the ultrafiltration membrane module 6. The inlet end of the circulation pipeline 110 is connected to the concentrate outlet of the ultrafiltration membrane module 6, and the outlet end of the circulation pipeline 110 is connected to the main pipeline 100 between the first check valve 32 and the inlet flow sensor 33. A reflux control valve 37, a first flow sensor 36, a circulation pump 7, and a second check valve 35 are sequentially connected to the circulation pipeline 110. The reflux control valve 37 is located near the concentrate outlet of the ultrafiltration membrane module 6.

[0044] Specifically, the value of the permeate flow sensor 38 can reflect the flux change of the ultrafiltration membrane module 6, and the value of the permeate pressure sensor 39 can reflect the fouling status of the ultrafiltration membrane module 6. When the permeate flow or pressure is low, the circulation pump 7 stops running, the cleaning pump 8 starts, and the ultrafiltration membrane cleaning system is started. When the fouling is severe, the metering pump 12 is turned on to pump the chemical cleaning agent in the dosing tank 13 into the cleaning water tank 10, and the heater 43 and the agitator 42 are turned on to heat and stir the cleaning solution, so that the cleaning solution chemically cleans the ultrafiltration membrane module 6 to restore its flux.

[0045] The ultrafiltration membrane module 6 employs multiple sets of parallel-connected polyceramic membranes. Specifically, the ultrafiltration membrane module 6 of the present invention employs two sets of parallel-connected polyceramic membranes or four sets of parallel-connected polyceramic membranes. The main component of the polyceramic membrane is an organometallic material. The polyceramic membrane has the characteristics of superhydrophilic and oleophobic surface, fouling resistance, and easy cleaning. It also has the advantages of low pressure drop in the direct current channel, tolerance to high suspended solids and high oil content wastewater, high filtration accuracy, concentrated pore size distribution, and resistance to deep fouling. The ultrafiltration membrane module can be cleaned efficiently and quickly using either permeate or chemical cleaning agents.

[0046] In the above embodiments, another optional implementation is as follows: an ozone aeration device 22 is provided inside the ozone catalytic device 23, and the inlet end of the ozone aeration device 22 is connected to the outlet end of the ozone delivery pipeline 121; an ozone catalyst 24 is provided near the bottom inside the ozone catalytic device 23, and the ozone catalyst 24 is located at the end of the ozone aeration device 22 away from the inlet of the ozone aeration device 22; the ozone catalytic device 23 is provided with an inlet end and an outlet end, the inlet end being located between the ozone aeration device 22 and the ozone catalyst 24; the outlet end being located on the side of the ozone catalyst 24 away from the ozone aeration device 22; the inlet end and the outlet end are connected to the main pipeline 100. Preferably, the ozone catalyst 24 is an aluminum-based or iron-based supported solid catalyst. This type of catalyst has the advantages of high stability, strong ozone mass transfer capacity, and high hydroxyl radical yield.

[0047] The inlet end of the ozone delivery pipeline 121 is connected to the oxygen cylinder 15. An ozone generator 16, an ozone detector 18, and a fourth check valve 20 are sequentially installed on the ozone delivery pipeline 121; the ozone generator 16 is located close to the oxygen cylinder 15. The exhaust gas treatment device 28 is connected to the exhaust outlet of the ozone catalytic device 23 through the exhaust gas discharge pipeline 122. The exhaust outlet is located at the end of the ozone catalytic device 23 furthest from the ozone aeration device 22.

[0048] The system also includes an inlet regulating valve 19 and a first inlet pump 21; the inlet regulating valve 19 and the first inlet pump 21 are sequentially arranged on the main pipeline 100 between the intermediate water tank 17 and the ozone catalytic device 23, and the first inlet pump 21 is closer to the intermediate water tank 17.

[0049] In this embodiment, the intermediate water tank 17 is also equipped with a liquid level sensor 45. The liquid level sensor 45 is linked with the high pressure pump 4 and the water inlet electric control valve 3. When the liquid level in the intermediate water tank 17 reaches a certain height, the high pressure pump 4 and the electric control valve 3 automatically shut down to ensure the dynamic and stable operation of the system.

[0050] In this invention, the system further includes an ultrafiltration membrane cleaning system, which includes a cleaning water tank 10. The first outlet of the cleaning water tank 10 is connected to the inlet of the second cleaning pipe 133, and the outlet of the second cleaning pipe 133 is connected to the main pipeline 100 between the first check valve 32 and the inlet flow sensor 33. A third check valve 31, a cleaning pump 8, and a cleaning valve 9 are sequentially arranged on the second cleaning pipe 133, with the cleaning valve 9 located on the side closer to the cleaning water tank 10. A heater 43 is provided in the cleaning water tank 10, located at the bottom of the cleaning water tank 10. The cleaning liquid return pipe 132 is connected to the first injection port of the cleaning water tank 10, and the inlet of the cleaning liquid return pipe 132 is connected to the main pipeline 100 between the permeate pressure sensor 39 and the membrane permeate control valve 41. A cleaning return valve 40 is provided on the cleaning liquid return pipe 132. The first injection port is located at the end of the first outlet away from the heater 43. The cleaning water tank 10 is equipped with a level gauge and an agitator 42, which are used to measure the water volume in the cleaning water tank 10 and to agitate the water with the agitator 42.

[0051] When the ultrafiltration membrane module 6 intercepts a large amount of particulate matter and organic pollutants, its filtration performance will decrease. At this time, the ultrafiltration membrane cleaning system is turned on, and the cleaning pump 8 is used to pump the water in the cleaning water tank 10 into the second cleaning pipe 133. After cleaning the ultrafiltration membrane module 6, it is returned to the cleaning water tank 10 through the cleaning liquid return pipe 132. This process is repeated to clean the ultrafiltration membrane module 6, so as to avoid the blockage inside the ultrafiltration membrane module 6 and affect the permeability of polluted groundwater.

[0052] In the above embodiment, another optional implementation is that the cleaning liquid discharge pipe 134 is connected to the second outlet of the cleaning water tank 10, and the outlet of the cleaning liquid discharge pipe 134 is connected to the top of the raw water tank 2; a cleaning water tank discharge valve 44 and a discharge pump 14 are provided on the cleaning liquid discharge pipe 134, with the cleaning water tank discharge valve 44 located on the side close to the cleaning water tank 10. After the ultrafiltration membrane module 6 is cleaned, by opening the cleaning water tank discharge valve 44 and the discharge pump 14, the cleaning liquid is mixed into the raw water tank 2 through the cleaning liquid discharge pipe 134, mixed with the raw water, and disposed of together, so that the entire system does not produce waste liquid.

[0053] The ultrafiltration membrane cleaning system also includes a dosing pipeline 135. The dosing tank 13 is connected to the top of the cleaning water tank 10 via the dosing pipeline 135. A flow control valve 11 and a metering pump 12 are sequentially installed on the dosing pipeline 135, with the metering pump 12 located near the dosing tank 13. The ultrafiltration membrane cleaning system also includes a first cleaning pipeline 131. The inlet end of the first cleaning pipeline 131 is connected to the product water tank 27, and the outlet end of the first cleaning pipeline 131 is connected to the second inlet of the cleaning water tank 10. The second inlet is located between the cleaning liquid discharge pipeline 134 and the dosing pipeline 135. A cleaning water replenishment pump 25 and a cleaning water replenishment valve 26 are installed on the first cleaning pipeline 131, with the cleaning water replenishment pump 25 located near the cleaning water tank 10. When the cleaning water tank 10 needs replenishment, the cleaning water replenishment pump 25 and the cleaning water replenishment valve 26 are opened, allowing water from the product water tank 27 to be pumped into the cleaning water tank 10 for replenishment.

[0054] Working principle:

[0055] The inlet pipe of raw water tank 2 is connected to the extraction system via inlet valve 1. The extraction system pumps the water to be treated into raw water tank 2. The water in raw water tank 2 is then opened via the electric control valve 3 and the high-pressure pump 4, allowing the water to enter the security filter 5 through the main pipeline 100. The security filter 5 is used to remove suspended particulate matter from the polluted groundwater to protect the ultrafiltration membrane module 6. The water then enters the ultrafiltration membrane module 6, which removes petroleum-like substances and large molecular organic matter from the water. The product water outlet is connected to the intermediate water tank 17 via the main pipeline 100 for further treatment. The concentrate water outlet is connected to the inlet of the ultrafiltration membrane module 6 via the circulation pipeline 110 for circulation treatment.

[0056] A liquid level sensor 45 is installed in the intermediate water tank 17. The liquid level sensor 45 is used to monitor the liquid level in the intermediate water tank 17. The liquid level sensor 45 is linked with the high pressure pump 4 and the inlet water control valve 3. When the liquid level sensor 45 detects that the water level is higher than a certain value, it controls the inlet water control valve 3 to close and the high pressure pump 4 to automatically shut down. When the liquid level sensor 45 detects that the water level is lower than a certain value, it controls the inlet water control valve 3 to open and the high pressure pump 4 to start to input raw water.

[0057] Water from intermediate water tank 17 is pumped into ozone catalytic device 23 via first inlet pump 21, and the inlet flow rate is regulated by inlet regulating valve 19 to control the hydraulic residence time. Simultaneously, ozone generator 16 is activated, using pure oxygen to produce ozone. The ozone gas enters the reactor through inlet pipe and ozone aeration device 22, where it reacts fully with the membrane-filtered permeate under the action of ozone catalyst 24, further reducing the content of organic pollutants in the polluted groundwater. After treatment by the ozone catalytic oxidation process, the final permeate enters permeate tank 27.

[0058] When the ultrafiltration membrane module 6 intercepts a large amount of particulate matter and organic pollutants, its filtration performance will decrease. At this time, the ultrafiltration membrane cleaning system is turned on, and the cleaning pump 8 is used to pump the water in the cleaning water tank 10 into the second cleaning pipe 133. After cleaning the ultrafiltration membrane module 6, it is returned to the cleaning water tank 10 through the cleaning liquid return pipe 132. This process is repeated to clean the ultrafiltration membrane module 6, so as to avoid the blockage inside the ultrafiltration membrane module 6 and affect the permeability of polluted groundwater.

[0059] In this embodiment, groundwater contaminated by a petrochemical waste disposal site was treated. The extracted groundwater had a chemical oxygen demand (COD) content of 2000 mg / L. After being treated by the ultrafiltration membrane filtration system 6, the COD was reduced to below 1000 mg / L. After being treated by the ozone catalytic device 23, the COD of the produced water was reduced to below 200 mg / L, thus achieving the effect of pollutant emission reduction.

[0060] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A groundwater treatment system, characterized in that, It includes a raw water tank (2), a security filter (5), an ultrafiltration membrane module (6), an intermediate water tank (17), an ozone treatment device, and a product water tank (27); The outlet of the raw water tank (2) is connected to the inlet of the main pipeline (100), and the outlet of the main pipeline (100) is connected to the product water tank (27). From the inlet to the outlet of the main pipeline (100), a security filter (5), an ultrafiltration membrane module (6), an intermediate water tank (17), and an ozone treatment device are connected in sequence.

2. The groundwater treatment system according to claim 1, characterized in that, The ultrafiltration membrane module (6) includes a first check valve (32), an inlet water flow sensor (33), an inlet water pressure sensor (34), a product water flow sensor (38), a product water pressure sensor (39), and a membrane product water control valve (41); A first check valve (32), an inlet flow sensor (33), and an inlet pressure sensor (34) are sequentially installed on the main pipeline (100) between the security filter (5) and the ultrafiltration membrane module (6); A permeate flow sensor (38), a permeate pressure sensor (39), and a membrane permeate control valve (41) are sequentially installed on the main pipeline (100) between the permeate outlet and the intermediate water tank (17) of the ultrafiltration membrane module (6). The first outlet of the ultrafiltration membrane module (6) is connected to the inlet end of the circulation pipe (110), and the outlet end of the circulation pipe (110) is connected to the main pipeline (100) between the first check valve (32) and the inlet flow sensor (33).

3. The groundwater treatment system according to claim 2, characterized in that, A reflux control valve (37), a first flow sensor (36), a circulation pump (7), and a second check valve (35) are sequentially connected to the circulation pipeline (110).

4. A groundwater treatment system according to claim 2, characterized in that, The ultrafiltration membrane module (6) uses multiple sets of ceramic membranes arranged in parallel.

5. A groundwater treatment system according to claim 1, characterized in that, The ozone treatment device includes an ozone catalytic device (23); The ozone catalytic device (23) is provided with an inlet end and an outlet end, which are connected to the main pipeline (100); An ozone aeration device (22) is provided at the bottom of the ozone catalytic device (23). The inlet of the ozone aeration device (22) passes through the ozone catalytic device (23) and is connected to the outlet end of the ozone delivery pipeline (121). An ozone catalyst (24) is provided inside the ozone catalytic device (23).

6. A groundwater treatment system according to claim 5, characterized in that, The ozone catalyst (24) is an aluminum-based or iron-based supported solid catalyst.

7. A groundwater treatment system according to claim 5, characterized in that, The inlet end of the ozone delivery pipeline (121) is connected to the oxygen cylinder (15). An ozone generator (16), an ozone detector (18), and a fourth check valve (20) are sequentially installed on the ozone delivery pipeline (121).

8. A groundwater treatment system according to claim 5, characterized in that, The ozone treatment device also includes an exhaust gas discharge pipe (122) and a tail gas treatment device (28), wherein the tail gas treatment device (28) is connected to the exhaust gas outlet of the ozone catalytic device (23) through the exhaust gas discharge pipe (122).

9. A groundwater treatment system according to claim 1, characterized in that, The system also includes an ultrafiltration membrane cleaning system, which includes a cleaning water tank (10); The first outlet of the cleaning water tank (10) is connected to the inlet end of the second cleaning pipe (133), and the outlet end of the second cleaning pipe (133) is connected to the main pipeline (100) between the first check valve (32) and the inlet flow sensor (33); a cleaning valve (9), a cleaning pump (8) and a third check valve (31) are sequentially installed on the second cleaning pipe (133); The first injection port of the cleaning water tank (10) is connected to the cleaning fluid return pipe (132), and the inlet end of the cleaning fluid return pipe (132) is connected to the main pipeline (100) between the product water pressure sensor (39) and the membrane product water control valve (41).

10. A groundwater treatment system according to claim 9, characterized in that, The ultrafiltration membrane cleaning system also includes a cleaning liquid discharge pipe (134), a cleaning water tank discharge valve (44), and a discharge pump (14). The cleaning liquid discharge pipe (134) is connected to the second outlet of the cleaning water tank (10), and the outlet of the cleaning liquid discharge pipe (134) is connected to the raw water tank (2). The cleaning water tank discharge valve (44) and the discharge pump (14) are sequentially installed on the cleaning liquid discharge pipe (134).

11. A groundwater treatment system according to claim 9, characterized in that, The ultrafiltration membrane cleaning system also includes a dosing tank (13), which is connected to the cleaning water tank (10) through a dosing pipe (135), and a metering pump (12) and a flow control valve (11) are sequentially installed on the dosing pipe (135).

12. A groundwater treatment system according to claim 9, characterized in that, The ultrafiltration membrane cleaning system also includes a cleaning water supply valve (26) and a cleaning water supply pump (25). The cleaning water supply valve (26) and the cleaning water supply pump (25) are connected in sequence to the first cleaning pipe (131). The inlet end of the first cleaning pipe (131) is connected to the water production tank (27), and the outlet end of the first cleaning pipe (131) is connected to the second injection port of the cleaning water tank (10).

13. A groundwater treatment system according to claim 1, characterized in that, An electric control valve (3) and a high-pressure pump (4) are connected in sequence on the main pipeline (100) between the raw water tank (2) and the security filter (5).

14. A groundwater treatment system according to claim 1, characterized in that, The groundwater treatment system also includes an inlet regulating valve (19) and a first inlet pump (21); the inlet regulating valve (19) and the first inlet pump (21) are connected in sequence to the main pipeline (100) between the intermediate water tank (17) and the ozone catalytic device (23).

Images