Low-drug coagulation-ultrafiltration device and secondary coagulation-ultrafiltration device for high turbidity

Abstract

A low-drug coagulation-ultrafiltration device and a secondary coagulation-ultrafiltration device for dealing with high turbidity belong to the field of water treatment technology. The present invention solves the problem of low water treatment efficiency and inability to deal with sudden high turbidity water treatment in existing water treatment equipment. It includes a low-drug coagulation-ultrafiltration device, an intermediate water tank and a second dosing assembly tank. The second dosing assembly tank is connected to the coagulation assembly tank through a pipeline. The water inlet and outlet of the intermediate water tank are connected to the upper part of the inclined tube sedimentation area and the upper part of the coagulation assembly tank through the fourth water inlet pipe and the fifth water inlet pipe respectively. The pipeline is controlled by setting valves on each pipeline. Adaptive treatment of high turbidity changes in raw water is achieved. In severe weather such as heavy rain, high turbidity water treatment is achieved by starting the intermediate water tank and adding potassium permanganate to strengthen secondary coagulation, thereby reducing the cost of chemicals and reducing the floor space. When the water quality conditions are normal, such as low turbidity, it can directly enter the membrane filtration assembly tank without passing through the intermediate water tank.

Description

Technical Field

[0001] The invention relates to a low-drug type coagulation-ultrafiltration device and a secondary coagulation-ultrafiltration device for coping with high turbidity, belonging to the technical field of water treatment. Background Art

[0002] In recent years, with the continuous increase in water demand in my country, the number of water plants and water supply have also increased accordingly. However, the traditional water supply plant often uses a simple treatment method of coagulation-sedimentation-filtration for the treatment of conventional surface water (i.e. low turbidity water). Its efficiency in removing suspended solids is poor, and the system structure is relatively complex, resulting in a large footprint, a time-consuming construction process and high costs.

[0003] In addition, conventional water treatment processes often cannot cope with sudden water quality problems, such as high turbidity water caused by heavy rain. Water plant design is often based on empirical data. Under normal circumstances, water treatment can often meet various water needs. However, heavy rain will bring a large amount of suspended matter including silt, soil, organic matter, etc. into the water source, causing high turbidity in the water source of the water supply plant. High turbidity water will cause difficulties in conventional treatment processes if it is not properly treated. Suspended matter will block pipes, sedimentation tanks, and membrane systems, reducing water treatment efficiency. In addition, suspended matter in highly turbid water adsorbs a large number of pathogenic microorganisms. If the water is not properly treated and drunk, it will cause waterborne diseases in the human body, such as diarrhea, dysentery, intestinal infections, etc. Therefore, in order to deal with the problem of high turbidity water, it is necessary to transform the traditional conventional treatment process.

[0004] When the water source has high turbidity due to heavy rain, traditional water plants often increase the dosage of the original water treatment system, which results in the disadvantages of large dosage of coagulants and high cost of chemicals. Traditional systems that treat high turbidity water alone often use the treatment measures of primary sedimentation-coagulation-secondary sedimentation-filtration, and the two-stage sedimentation method has the disadvantage of large land occupation. Therefore, traditional water plants use traditional methods of transforming water plants that treat high turbidity water sources to deal with sudden high turbidity water, which not only increases the cost of chemicals, but also causes construction difficulties and large land occupation.

[0005] Therefore, there is an urgent need for a water treatment device and a water treatment method that can not only efficiently treat conventional surface water, but also cope with sudden high-turbidity water treatment problems through simple modifications. Summary of the invention

[0006] The present invention aims to solve the problems of low water treatment efficiency and inability to cope with sudden high turbidity water in existing water treatment equipment, and further provides a low-drug type coagulation-ultrafiltration device and a secondary coagulation-ultrafiltration device for coping with high turbidity.

[0007] The technical solution adopted by the present invention to solve the above technical problems is:

[0008] Technical Solution 1: A low-drug coagulation-ultrafiltration device, comprising a coagulation assembly tank, a contact flocculation assembly tank, a membrane filtration assembly tank, a water outlet tank and a first drug dosing assembly tank, wherein the first drug dosing assembly tank is connected to the coagulation assembly tank through a pipeline, the coagulation assembly tank is connected to a first water inlet pipe, a flocculation zone and an inclined tube sedimentation zone are arranged in the contact flocculation assembly tank, the upper part of the flocculation zone is connected to the lower part of the inclined tube sedimentation zone, the flocculation zone is connected to the coagulation assembly tank through a second water inlet pipe, the membrane filtration assembly tank is connected to the upper part of the inclined tube sedimentation zone through a third water inlet pipe, a membrane aeration system is arranged in the membrane filtration assembly tank, and the outlet of the membrane filtration assembly tank is connected to the water outlet tank through an outlet pipe, and the pipeline is controlled to be on and off by arranging valves on each pipeline.

[0009] Furthermore, the contact flocculation assembly tank includes a main shell, a baffle and a partition, wherein the partition is offset from top to bottom and fixed in parallel in the main shell, a channel is formed between the baffle and the partition, the top end of the channel is connected to the flocculation area, and the bottom end of the channel is connected to the inclined tube sedimentation area.

[0010] Furthermore, a water inlet distributor, gravel and a self-cleaning component for washing gravel are provided in the flocculation area. The water inlet distributor is arranged in the middle of the flocculation area and is connected to the second water inlet pipe. The wastewater outlet of the self-cleaning component is connected to the coagulation assembly tank through the wastewater pipe.

[0011] Furthermore, stirring devices are respectively arranged inside the coagulation assembly tank and the first dosing assembly tank, and the bottoms of the coagulation assembly tank, the contact flocculation assembly tank, the membrane filtration assembly tank and the outlet tank are all connected with vent pipes. Perforated mud discharge pipes are also arranged at the bottoms of the contact flocculation assembly tank and the membrane filtration assembly tank, and the bottoms of the contact flocculation assembly tank and the membrane filtration assembly tank are both tapered structures.

[0012] Technical Solution 2: A method for using the above-mentioned low-drug coagulation-ultrafiltration device, comprising the following steps:

[0013] Step 1: determine the dosage of polyaluminium chloride through a small test, add the corresponding amount of polyaluminium chloride into the first dosing assembly tank, and after fully dissolving under the action of the first stirring device, add it to the coagulation assembly tank, open the first water inlet valve on the first water inlet pipe, and introduce the raw water to be treated, and at the same time open the third water inlet valve on the third water inlet pipe to form a continuous flow system;

[0014] Step 2: fully mix the polyaluminium chloride coagulant in the coagulation assembly tank, and flow it into the contact flocculation assembly tank through the second water inlet pipe. In the flocculation area, the gravel acts as a coagulant to adsorb and neutralize the charges on the surface of the suspended particles, and then the pollutants adsorbed on the surface of the gravel are washed by the self-cleaning component. The washed gravel falls back to the filter layer, and the washing wastewater generated by the self-washing component flows back into the coagulation assembly tank through the wastewater pipe. The water to be treated after adsorption in the flocculation area enters the inclined tube sedimentation area through the upper part of the flocculation area for sedimentation;

[0015] Step 3: The effluent from the contact flocculation assembly tank enters the membrane filtration assembly tank through the third water inlet pipe, and the effluent from the membrane filtration assembly tank enters the effluent tank by siphoning.

[0016] Technical Solution Three: A secondary coagulation-ultrafiltration device for dealing with high turbidity, comprising the low-drug type coagulation-ultrafiltration device in claim 1, an intermediate water tank and a second dosing assembly tank, wherein the second dosing assembly tank is connected to the coagulation assembly tank through a pipeline, and the water inlet and outlet of the intermediate water tank are connected to the upper part of the inclined tube sedimentation zone and the upper part of the coagulation assembly tank through a fourth water inlet pipe and a fifth water inlet pipe respectively, and the pipeline is opened and closed by setting valves on each pipeline.

[0017] Furthermore, the contact flocculation assembly tank includes a main shell, a baffle and a partition, wherein the partition is offset from top to bottom and fixed in parallel in the main shell, a channel is formed between the baffle and the partition, the top end of the channel is connected to the flocculation area, and the bottom end of the channel is connected to the inclined tube sedimentation area.

[0018] Furthermore, a water inlet distributor, gravel and a self-cleaning component for washing gravel are provided in the flocculation area. The water inlet distributor is arranged in the middle of the flocculation area and is connected to the second water inlet pipe. The wastewater outlet of the self-cleaning component is connected to the coagulation assembly tank through the wastewater pipe.

[0019] Furthermore, stirring devices are respectively arranged inside the coagulation assembly tank, the first dosing assembly tank and the second dosing assembly tank; the bottoms of the coagulation assembly tank, the contact flocculation assembly tank, the membrane filtration assembly tank, the outlet tank and the intermediate water tank are all connected with vent pipes; the bottoms of the contact flocculation assembly tank and the membrane filtration assembly tank are also provided with perforated mud discharge pipes; the bottoms of the contact flocculation assembly tank and the membrane filtration assembly tank are both tapered structures.

[0020] Technical Solution 4: A method for using the above-mentioned secondary coagulation-ultrafiltration device for dealing with high turbidity, comprising the following steps:

[0021] Step 1: Add a corresponding amount of polyaluminium chloride into the first dosing assembly tank, and add a corresponding amount of potassium permanganate-enhanced ferric chloride coagulant into the second dosing assembly tank;

[0022] Step 2: Open the first water inlet valve to pass the raw water to be treated, open the fourth water inlet valve, so that the coagulation assembly tank, the contact flocculation assembly tank and the intermediate water tank form a circulation system. When the first batch of water enters the intermediate water tank, close the first water inlet valve, fully mix the polyaluminum chloride coagulant in the coagulation assembly tank, enter the contact flocculation assembly tank to complete the first flocculation and the first precipitation, then enter the coagulation assembly tank after passing through the intermediate water tank, and then fully mix the potassium permanganate-enhanced ferric chloride coagulant in the coagulation assembly tank, and flow into the contact flocculation assembly tank to complete the secondary flocculation and the secondary precipitation;

[0023] Step 3: close the fourth water inlet valve, open the third water inlet valve, wait for the first batch of treated water in step 2 to enter the membrane filter assembly pool, close the third water inlet valve, open the fourth water inlet valve, and perform secondary coagulation treatment on the next batch of raw water to be treated;

[0024] Step 4: After the first batch of effluent enters the membrane filtration assembly pool, it enters the effluent pool through siphoning.

[0025] Compared with the prior art, the present invention has the following effects:

[0026] 1. By integrating the flocculation zone and the inclined tube sedimentation zone in the contact flocculation assembly tank, the sand and gravel in the flocculation zone enter the inclined tube sedimentation zone to be intercepted and recycled to the next process, thereby preventing the sand and gravel from directly entering the membrane filtration assembly tank and damaging the membrane system. At the same time, the integrated flocculation zone and inclined tube sedimentation zone can effectively aggregate suspended particles, thereby effectively improving the removal efficiency of suspended matter. Compared with the existing water treatment equipment, the water treatment efficiency is higher.

[0027] 2. The low-drug coagulation-ultrafiltration device of the present invention can effectively save operating costs and operating time when treating conventional water sources such as non-high turbidity water sources or low turbidity water sources; a continuous flow system is formed, the hydraulic load is higher, the process flow is simpler, and the operation management is more convenient.

[0028] 3. The secondary coagulation-ultrafiltration device for dealing with high turbidity in the present invention can further aggregate and condense suspended matter particles through secondary coagulation to form larger and heavier aggregates, thereby improving the removal efficiency of suspended matter.

[0029] The device of the present invention can realize adaptive treatment of high turbidity changes of raw water. For example, in severe weather such as heavy rain, high turbidity water treatment can be achieved by starting the intermediate water tank and adding potassium permanganate to strengthen secondary coagulation, thereby reducing the cost of reagents and the floor space. When the water quality is normal such as low turbidity, it can directly enter the membrane filtration assembly tank without passing through the intermediate water tank, so that the effluent can be stable and meet the standards.

[0030] Potassium permanganate reagent is added into the secondary coagulation to reduce the dosage of coagulant and achieve the treatment of organic matter in highly turbid water. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a low-drug type coagulation-ultrafiltration device according to a specific implementation mode 1;

[0032] Figure 2 It is a schematic structural diagram of a secondary coagulation-ultrafiltration device for coping with high turbidity according to a second specific implementation method.

[0033] In the figure: A, coagulation assembly tank; B, contact flocculation assembly tank; C, flocculation area; D, inclined tube sedimentation area; E, intermediate water tank; F, first dosing assembly tank; G, second dosing assembly tank; H, membrane filtration assembly tank; I, outlet tank;

[0034] 101. Main shell; 102. Baffle; 103. Partition; 32. Aeration device; 33. Hollow fiber membrane assembly; 5. Dosing pump; 2. First water inlet valve; 25. Third water inlet valve; 29. ​​Second air pump; 30. Second air valve; 31. Second gas flowmeter; 34. Liquid flowmeter; 35. Exhaust valve; 8. Inlet water distributor; 13. Gravel; 14. Air lift sand conveying pipe; 16. Filter sand cleaning pipe; 15. Wastewater output device; 12. Air distribution pipe; 9. First air pump; 10. First air valve; 11. First gas flowmeter; 3. Stirring device; 19. Perforated mud discharge pipe; 23. Fourth water inlet valve. DETAILED DESCRIPTION

[0035] Specific implementation method 1: Combination Figure 1 To illustrate the present embodiment, a low-drug coagulation-ultrafiltration device comprises a coagulation assembly tank A, a contact flocculation assembly tank B, a membrane filtration assembly tank H, a water outlet tank I and a first drug adding assembly tank F, wherein the first drug adding assembly tank F is connected to the coagulation assembly tank A through a pipeline, the coagulation assembly tank A is connected to a first water inlet pipe, a flocculation zone C and an inclined tube sedimentation zone D which are connected are arranged in the contact flocculation assembly tank B, the upper part of the flocculation zone C is connected to the lower part of the inclined tube sedimentation zone D, the flocculation zone C is connected to the coagulation assembly tank A through a second water inlet pipe, the membrane filtration assembly tank H is connected to the upper part of the inclined tube sedimentation zone D through a third water inlet pipe, a membrane aeration system is arranged in the membrane filtration assembly tank H, and the water outlet of the membrane filtration assembly tank H is connected to the water outlet tank I through a water outlet pipe, and the pipeline is controlled to be on and off by arranging valves on each pipeline.

[0036] The first dosing assembly tank F is a polyaluminium chloride coagulation dosing assembly tank. A dosing pump 5 is arranged on the connecting pipeline between the first dosing assembly tank F and the coagulation assembly tank A, so as to facilitate dosing of the agent into the coagulation assembly tank A.

[0037] By integrating the flocculation zone C and the inclined tube sedimentation zone D in the contact flocculation assembly tank B, the gravel 13 in the flocculation zone C enters the inclined tube sedimentation zone D for interception and is recycled to the next process, thereby preventing the gravel 13 from directly entering the membrane filtration assembly tank H and damaging the membrane system. At the same time, the integrated flocculation zone C and the inclined tube sedimentation zone D can effectively aggregate suspended matter particles, thereby effectively improving the removal efficiency of suspended matter. Compared with existing surface water treatment equipment, the water treatment efficiency is higher.

[0038] The low-drug coagulation-ultrafiltration device of the present invention can effectively save operating costs and operating time when treating conventional water supply such as non-high turbidity water sources or low turbidity water sources.

[0039] The low-drug coagulation-ultrafiltration device of the present invention forms a continuous flow system for the entire device by opening the first water inlet pipe, the second water inlet pipe, the third water inlet pipe and the water outlet pipe, with a higher hydraulic load, a simpler process flow and more convenient operation and management.

[0040] All pipelines in the present invention are made of polyethylene.

[0041] The first water inlet pipe is provided with a first water inlet valve 2, and the third water inlet pipe is provided with a third water inlet valve 25. An intelligent control system is adopted to realize automatic control of the system by controlling the opening and closing of each valve.

[0042] The coagulation assembly tank A, the contact flocculation assembly tank B, the membrane filtration assembly tank H, the effluent tank I and the first dosing assembly tank F all adopt assembly equipment, which are prefabricated and processed through plates. They occupy a small area and are convenient. They can not only greatly save the construction time when used in the process construction of new water plants, but also can be built on the basis of the original process when the old water plants are renovated, effectively saving the renovation time and cost.

[0043] An aeration device 32 and a plurality of hollow fiber membrane assemblies 33 arranged above the aeration device 32 are arranged in the membrane filtration assembly pool H, and the aeration device 32 adopts programmed aeration. With such a design, programmed aeration is adopted to form uniform microbubbles, and the membrane assembly is oxygenated and backwashed, and the membrane pollutants adsorbed on the hollow fiber membrane assembly 33 are backwashed. The hollow fiber membrane assembly 33 adopts an immersed membrane assembly, and the material is polyether cellulose acetate ester, cellulose acetate or polyamide; the hollow fiber membrane assembly 33 adopts a low-gravity siphon water outlet method, and there is no need to design a separate hydraulic cleaning and chemical cleaning device, and continuous water outlet can be achieved. The structure and working principle of the aeration device 32 and the hollow fiber membrane assembly 33 used in the present invention are all prior art, and will not be repeated here.

[0044] The membrane filter assembly pool H is externally connected to a second air pump 29, and a second air valve 30 and a second gas flow meter 31 are provided on the connecting pipeline between the second air pump 29 and the aeration device 32. A liquid flow meter 34 and an exhaust valve 35 are provided on the outlet pipe between the membrane filter assembly pool H and the outlet pool I.

[0045] The device of the present invention can adopt an integrated solar cell power supply system to provide the power required by the system, which is green and environmentally friendly. At the same time, a municipal power supply line is added as an emergency to avoid the equipment from not being able to operate normally due to insufficient power supply from solar cells in rainy weather.

[0046] The contact flocculation assembly tank B comprises a main shell 101, a baffle 102 and a partition 103, wherein the partition 103 is staggered with the baffle 102 and fixed in parallel in the main shell 101, and a channel is formed between the baffle 102 and the partition 103, the top end of the channel is connected to the flocculation zone C, and the bottom end of the channel is connected to the inclined tube sedimentation zone D. In this design, by setting the baffle 102 and the partition 103, a partition is formed in the main shell 101, the flocculation zone C is formed between the baffle 102 and the main shell 101 on the same side, and the inclined tube sedimentation zone D is formed between the baffle 103 and the main shell 101 on the same side. The partition 103 is arranged higher than the baffle 102 to separate the upper part of the flocculation zone C from the upper part of the inclined tube sedimentation zone D, so as to prevent the effluent of the flocculation zone C from directly entering the inclined tube sedimentation zone D through the upper part and affecting the sedimentation effect. By integrating the flocculation zone C with the inclined tube sedimentation zone D, the floor space of the contact flocculation assembly tank B is effectively reduced. At the same time, an assembly is formed to facilitate system assembly and application.

[0047] The flocculation zone C is provided with a water inlet distributor 8, gravel 13 and a self-cleaning assembly for washing the gravel 13. The water inlet distributor 8 is arranged in the middle of the flocculation zone C and is connected to the second water inlet pipe. The wastewater outlet of the self-cleaning assembly is connected to the coagulation assembly tank A through the wastewater pipe. With such a design, by setting the water inlet distributor 8, it is convenient to distribute water into the flocculation zone C. By setting the gravel 13 in the flocculation zone C, it can be used as a coagulant to adsorb and neutralize the charges on the surface of the suspended particles, promote the adsorption bridging effect between the particles, and the gaps between the gravel 13 particles can provide a bridging effect for connecting the particles to each other. When the gravel 13 particles come into contact with the suspended particles, the suspended particles can be deposited in the gaps between the gravel 13 particles and form aggregates. This bridging effect helps to increase the aggregate size and density of the suspended matter, promote the sedimentation of the suspended matter, and improve the removal efficiency of the suspended matter.

[0048] The gravel 13 inside the flocculation zone C forms dirty sand after adsorption. By setting a self-cleaning component inside the flocculation zone C, the dirty sand inside the flocculation zone C is cleaned, so that the gravel 13 inside the flocculation zone C can be recycled, effectively saving the operating cost of the device. The cleaning wastewater after cleaning the dirty sand flows back to the coagulation assembly tank A through the wastewater pipe. The self-cleaning component includes an air lift sand conveying pipe 14, a filter sand cleaning pipe 16 and a wastewater output device 15. The self-cleaning component used in the present invention is a prior art, such as a continuous flow sand filter, so the specific structural composition of the self-cleaning component is not repeated in this application. An air distribution pipe 12 is set at the lower part of the flocculation zone C, and the first air pump 9 distributes air to the flocculation zone C through the air distribution pipe 12. The air-water mixture below the air lift sand conveying pipe 14 is sucked into the air lift sand conveying pipe 14 under the pressure difference between the inside and outside of the pipe, and the gravel 13 is flushed under the shear force in the air lift sand conveying pipe 14. The first air valve 10 and the first gas flowmeter 11 are arranged on the connecting pipeline between the first air pump 9 and the air distribution pipe 12. With such a design, by distributing air at the lower part of the flocculation zone C, air and water form a gas-water mixture in the air lift sand conveying pipe 14. Since the density of the gas-water mixture is much smaller than that of water, the pressure difference between the inside and outside of the pipe drives the gas-water mixture to flow from bottom to top through the pipe at high speed, and forms a low pressure at the lower end of the pipe, sucking the surrounding water and sand into the air lift sand conveying pipe 14, and washing the pollutants on the surface of the gravel 13 under the shear force of the high-speed fluid in the pipe; the air, water and gravel 13 are separated at the outlet of the upper end of the air lift sand conveying pipe 14, and the gravel 13 falls back to the filter layer, and the washing wastewater is collected by the wastewater output device 15 and then flows back to the coagulation assembly tank A; since the filter material of the filter layer at the lower part of the flocculation zone C is continuously sucked away, the filter layer gradually moves downward, and the filter material in the filter layer can be circulated and washed once after a certain period of time, effectively saving the cost of washing the gravel 13.

[0049] A stirring device 3 is respectively arranged inside the coagulation assembly tank A and the first dosing assembly tank F. The bottoms of the coagulation assembly tank A, the contact flocculation assembly tank B, the membrane filtration assembly tank H and the outlet tank I are all connected with a vent pipe. The bottoms of the contact flocculation assembly tank B and the membrane filtration assembly tank H are also provided with a perforated mud discharge pipe 19. The bottoms of the contact flocculation assembly tank B and the membrane filtration assembly tank H are both tapered structures. With such a design, by adopting a mechanical stirring device 3, the rapid dissolution of the agent is promoted, the cost of the agent is reduced, and the water treatment efficiency is effectively improved. A vent valve is arranged on each vent pipe and the perforated mud discharge pipe 19. By arranging the perforated mud discharge pipe 19 at the bottom of the contact flocculation assembly tank B and the membrane filtration assembly tank H, it is convenient to discharge sand and mud from the inclined tube sedimentation area D of the contact flocculation assembly tank B and the membrane filtration assembly tank H. Specifically, the perforated mud discharge pipe 19 in the contact flocculation assembly tank B is used to discharge the sludge in the inclined tube sedimentation area D and the gravel 13 washed away by the flocculation area C. The leaked gravel 13 can be collected regularly and put into the flocculation area C to replenish the amount of gravel 13 in the flocculation area C; the empty hole mud discharge pipe in the membrane filtration assembly tank H is used to discharge the sludge in the membrane filtration assembly tank H. By setting the bottom of the contact flocculation assembly tank B and the bottom of the membrane filtration assembly tank H as a tapered structure, the bottom of the contact flocculation assembly tank B and the bottom of the membrane filtration assembly tank H form a large slope, which can effectively prevent the sludge from floating up, so that the sludge can gather at the bottom, achieve good sedimentation conditions, and facilitate sludge discharge.

[0050] A method for using the low-drug type coagulation-ultrafiltration device comprises the following steps:

[0051] Step 1: Determine the dosage of polyaluminium chloride through a small test, add the corresponding amount of polyaluminium chloride into the first dosing assembly tank F, and after it is fully dissolved under the action of the first stirring device 3, add it to the coagulation assembly tank A, open the first water inlet valve 2 on the first water inlet pipe, and introduce the raw water to be treated, and at the same time open the third water inlet valve 25 on the third water inlet pipe to form a continuous flow system;

[0052] Step 2: The polyaluminium chloride coagulant is fully mixed in the coagulation assembly tank A and flows into the contact flocculation assembly tank B through the second water inlet pipe. In the flocculation area C, the gravel 13 acts as a coagulant to adsorb and neutralize the charges on the surface of the suspended particles. Then, the pollutants adsorbed on the surface of the gravel 13 are washed by the self-cleaning component. The washed gravel 13 falls back to the filter layer. The flushing wastewater generated by the self-washing component flows back into the coagulation assembly tank A through the wastewater pipe. The water to be treated after adsorption in the flocculation area C enters the inclined tube sedimentation area D through the upper part of the flocculation area C for precipitation. In the flocculation area C, the first air pump 9 distributes air to the flocculation area C through the air distribution pipe 12. The gravel 13 acts as a coagulant to adsorb and neutralize the charges on the surface of the suspended particles, promoting the adsorption bridging effect between the particles. The gaps between the gravel 13 particles can provide a bridging effect for the particles to connect with each other. When the gravel 13 particles contact the suspended particles, the suspended particles can be deposited in the gaps between the gravel 13 particles and form aggregates. This bridging effect helps to increase the aggregate size and density of suspended matter, promotes the sedimentation of suspended matter, and improves the removal efficiency of suspended matter.

[0053] Air is distributed at the bottom, and air and water form an air-water mixture in the air lift sand conveying pipe 14. Since the density of the air-water mixture is much smaller than that of water, the pressure difference inside and outside the pipe drives the air-water mixture to flow from bottom to top through the pipeline at high speed, and forms a low pressure at the lower end of the pipe, sucking the surrounding water and sand into the air lift sand conveying pipe 14, and the pollutants on the surface of the gravel 13 are washed down under the shear force of the high-speed fluid in the pipe; air, water and gravel 13 are separated at the outlet of the upper end of the air lift sand conveying pipe 14, and the gravel 13 falls back to the filter layer, and the flushing wastewater is collected by the wastewater output device 15 and then returned to the coagulation assembly tank A; since the filter material of the filter layer at the bottom of the flocculation area C is continuously sucked away, the filter layer gradually moves downward, and the filter material in the filter layer can be circulated and washed once after a certain period of time.

[0054] Step 3: The effluent from the contact flocculation assembly tank B enters the membrane filtration assembly tank H through the third water inlet pipe, and the effluent from the membrane filtration assembly tank H enters the effluent tank I by siphoning. With this design, the water quality in the effluent tank I stably meets the "Sanitary Standard for Drinking Water" (GB5749-2022).

[0055] Specific implementation method 2: Combination Figure 2The present embodiment is described, and the secondary coagulation-ultrafiltration device for dealing with high turbidity includes a coagulation assembly tank A, a contact flocculation assembly tank B, a membrane filtration assembly tank H, a water outlet tank I, an intermediate water tank E, a first dosing assembly tank F and a second dosing assembly tank G, wherein the first dosing assembly tank F and the second dosing assembly tank G are connected to the coagulation assembly tank A through pipelines, the coagulation assembly tank A is connected to a first water inlet pipe, and a flocculation zone C and an inclined tube sedimentation zone D are arranged in the contact flocculation assembly tank B, and the upper part of the flocculation zone C is connected to the inclined tube sedimentation zone D. The lower part of the tube sedimentation zone D is connected, the flocculation zone C is connected to the coagulation assembly tank A through the second water inlet pipe, the membrane filtration assembly tank H is connected to the upper part of the inclined tube sedimentation zone D through the third water inlet pipe, a membrane aeration system is arranged in the membrane filtration assembly tank H, and the outlet of the membrane filtration assembly tank H is connected to the outlet tank I through the outlet pipe, the water inlet and outlet of the intermediate water tank E are connected to the upper part of the inclined tube sedimentation zone D and the upper part of the coagulation assembly tank A through the fourth water inlet pipe and the fifth water inlet pipe respectively, and the pipeline is opened and closed by arranging valves on each pipeline.

[0056] The first dosing assembly tank F is a polyaluminium chloride coagulation dosing assembly tank, and the second dosing assembly tank G is a potassium permanganate enhanced ferric chloride coagulation dosing assembly tank. Dosing pumps 5 are provided on the connecting pipelines between the first dosing assembly tank F and the second dosing assembly tank G and the coagulation assembly tank A, so as to facilitate the dosing of reagents into the coagulation assembly tank A.

[0057] The outlet of the inclined tube sedimentation zone D is arranged at the upper portion of the inclined tube sedimentation zone D.

[0058] Valves are respectively arranged on the first water inlet pipe, the third water inlet pipe, the fourth water inlet pipe and the water outlet pipe to control the on and off of the pipes. Among them, the first water inlet pipe is provided with a first water inlet valve 2, the third water inlet pipe is provided with a third water inlet valve 25, the fourth water inlet pipe is provided with a fourth water inlet valve 23, and the water outlet pipe is provided with a water outlet valve. An intelligent control system is adopted to realize automatic control of the device by controlling the opening and closing of each valve.

[0059] By integrating the flocculation zone C and the inclined tube sedimentation zone D in the contact flocculation assembly tank B, the gravel 13 in the flocculation zone C enters the inclined tube sedimentation zone D for interception and is recycled to the next process, thereby preventing the gravel 13 from directly entering the membrane filtration assembly tank H and damaging the membrane system. At the same time, the integrated flocculation zone C and the inclined tube sedimentation zone D can effectively aggregate suspended matter particles, thereby effectively improving the removal efficiency of suspended matter. Compared with the existing water treatment equipment, the water treatment efficiency is higher.

[0060] The opening and closing of the third water inlet valve 25 and the fourth water inlet valve 23 are controlled by an automatic control device to treat high turbidity water. The secondary coagulation-ultrafiltration device for coping with high turbidity of the present invention can be circulated in two sequential batch water inlet modes. Specifically, the first sequential batch: close the third water inlet valve 25, open the first water inlet valve 2 and the fourth water inlet valve 23, close the first water inlet valve 2 when the water enters the intermediate water tank E, and form an internal circulation through the intermediate water tank E; the second sequential batch: open the third water inlet valve 25, close the first water inlet valve 2 and the fourth water inlet valve 23, and realize secondary coagulation, secondary flocculation, and secondary sedimentation.

[0061] By adding a small amount of potassium permanganate to strengthen the coagulation method, the organic matter adsorbed on the suspended particles can be degraded and removed, so that the tiny suspended matter can be better exposed and interact with the coagulant, neutralizing the surface charge and destroying the electrical stability. While reducing the amount of coagulant, the organic matter treatment and removal of highly turbid water can be achieved, and the total drug consumption cost can be reduced by 30% compared with traditional methods.

[0062] In the prior art, primary coagulation has limited effect on fine and difficult-to-sediment suspended particles. In the present invention, secondary coagulation is used to further aggregate and condense suspended particles to form larger and heavier aggregates, thereby improving the removal efficiency of suspended matter.

[0063] The device of the present invention can achieve adaptive treatment of high turbidity changes in raw water. For example, in severe weather such as heavy rain, high turbidity water treatment can be achieved by starting the intermediate water tank E and adding potassium permanganate to strengthen secondary coagulation, thereby reducing the cost of chemicals and the floor space. The final effluent can stably meet the "Sanitary Standard for Drinking Water" (GB5749-2022). When it is normal water quality conditions such as low turbidity, it can directly enter the membrane filtration assembly tank H without passing through the intermediate water tank E, so that the effluent can stably meet the "Sanitary Standard for Drinking Water" (GB5749-2022).

[0064] Potassium permanganate reagent is added into the secondary coagulation to reduce the dosage of coagulant and achieve the treatment of organic matter in highly turbid water.

[0065] All pipelines in the present invention are made of polyethylene.

[0066] The coagulation assembly tank A, the contact flocculation assembly tank B, the membrane filtration assembly tank H, the effluent tank I, the intermediate water tank E, the first dosing assembly tank F and the second dosing assembly tank G all adopt assembly equipment, which are prefabricated and processed through plates. They occupy a small area and are convenient. They can not only greatly save the construction time when applied to the process construction of new water plants, but also can be built on the basis of the original process when the old water plants are renovated. By controlling the residence time of the intermediate water tank E, secondary coagulation is achieved. Compared with the traditional process, the floor space is greatly reduced, and the renovation time and cost are effectively saved.

[0067] An aeration device 32 and several hollow fiber membrane modules 33 arranged above the aeration device 32 are arranged in the membrane filtration assembly pool H, and the aeration device 32 adopts program aeration. Continuous, intermittent or pulsed aeration can effectively control membrane pollution while saving aeration energy consumption; and a microbubble aeration device 32 is used to obtain a higher cross-flow velocity and a lower rising resistance, which has a good cleaning effect on the membrane module but will not damage the membrane module. In this design, program aeration is used to form uniform microbubbles, and the membrane module is oxygenated and backwashed to backwash the membrane pollutants adsorbed on the hollow fiber membrane module 33. The hollow fiber membrane module 33 adopts an immersed membrane module, and the material is polyether cellulose acetate ester, cellulose acetate or polyamide; the hollow fiber membrane module 33 adopts a low-gravity siphon water outlet method, and no longer needs to design a separate hydraulic cleaning and chemical cleaning device, and continuous water outlet can be achieved. The water outlet power energy consumption cost is low, energy consumption is saved, and the requirements of equipment, pipelines and accessories for water inlet pressure are reduced. The structures and working principles of the aeration device 32 and the hollow fiber membrane assembly 33 used in the present invention are prior art and will not be described in detail here.

[0068] Based on the mathematical relationship between parameters such as membrane resistance and membrane flux, an intelligent membrane flux prediction aeration assembly module is formed, which shows stable membrane flux and stable effluent water quality.

[0069] The membrane filter assembly pool H is externally connected to a second air pump 29, and a second air valve 30 and a second gas flow meter 31 are provided on the connecting pipeline between the second air pump 29 and the aeration device 32. A liquid flow meter 34 and an exhaust valve 35 are provided on the outlet pipe between the membrane filter assembly pool H and the outlet pool I.

[0070] The processing system of the present invention can adopt an integrated solar cell power supply system to provide the power required by the system, which is green and environmentally friendly. At the same time, a municipal power supply line is added as an emergency to avoid the equipment from not being able to operate normally due to insufficient power supply from solar cells in rainy weather.

[0071] The contact flocculation assembly tank B comprises a main shell 101, a baffle 102 and a partition 103, wherein the partition 103 is staggered with the baffle 102 and fixed in parallel in the main shell 101, and a channel is formed between the baffle 102 and the partition 103, the top end of the channel is connected to the flocculation zone C, and the bottom end of the channel is connected to the inclined tube sedimentation zone D. In this design, by setting the baffle 102 and the partition 103, a partition is formed in the main shell 101, the flocculation zone C is formed between the baffle 102 and the main shell 101 on the same side, and the inclined tube sedimentation zone D is formed between the baffle 103 and the main shell 101 on the same side. The partition 103 is arranged higher than the baffle 102 to separate the upper part of the flocculation zone C from the upper part of the inclined tube sedimentation zone D, so as to prevent the effluent of the flocculation zone C from directly entering the inclined tube sedimentation zone D through the upper part and affecting the sedimentation effect. By integrating the flocculation zone C with the inclined tube sedimentation zone D, the floor space of the contact flocculation assembly tank B is effectively reduced. At the same time, an assembly is formed to facilitate system assembly and application.

[0072] The flocculation zone C is provided with a water inlet distributor 8, gravel 13 and a self-cleaning assembly for washing the gravel 13. The water inlet distributor 8 is arranged in the middle of the flocculation zone C and is connected to the second water inlet pipe. The wastewater outlet of the self-cleaning assembly is connected to the coagulation assembly tank A through the wastewater pipe. With such a design, by setting the water inlet distributor 8, it is convenient to distribute water into the flocculation zone C. By setting the gravel 13 in the flocculation zone C, it can be used as a coagulant to adsorb and neutralize the charges on the surface of the suspended particles, promote the adsorption bridging effect between the particles, and the gaps between the gravel 13 particles can provide a bridging effect for connecting the particles to each other. When the gravel 13 particles come into contact with the suspended particles, the suspended particles can be deposited in the gaps between the gravel 13 particles and form aggregates. This bridging effect helps to increase the aggregate size and density of the suspended matter, promote the sedimentation of the suspended matter, and improve the removal efficiency of the suspended matter.

[0073] The gravel 13 inside the flocculation zone C forms dirty sand after adsorption. By setting a self-cleaning component inside the flocculation zone C, the dirty sand inside the flocculation zone C is cleaned, so that the gravel 13 inside the flocculation zone C can be recycled, effectively saving the system operation cost. The cleaning wastewater after cleaning the dirty sand flows back to the coagulation assembly tank A through the wastewater pipe. The self-cleaning component includes an air lift sand conveying pipe 14, a filter sand cleaning pipe 16 and a wastewater output device 15. The self-cleaning component is a prior art, such as a continuous flow sand filter. Therefore, the specific structural composition of the self-cleaning component is not repeated in the present invention. An air distribution pipe 12 is set at the lower part of the flocculation zone C. The first air pump 9 distributes air to the flocculation zone C through the air distribution pipe 12. The air-water mixture below the air lift sand conveying pipe 14 is sucked into the air lift sand conveying pipe 14 under the pressure difference between the inside and outside of the pipe, and the gravel 13 is flushed under the shear force in the air lift sand conveying pipe 14. The first air valve 10 and the first gas flowmeter 11 are arranged on the connecting pipeline between the first air pump 9 and the air distribution pipe 12. With such a design, by distributing air at the lower part of the flocculation zone C, air and water form a gas-water mixture in the air lift sand conveying pipe 14. Since the density of the gas-water mixture is much smaller than that of water, the pressure difference inside and outside the pipe drives the gas-water mixture to flow from bottom to top through the pipe at high speed, and forms a low pressure at the lower end of the pipe, sucking the surrounding water and sand into the air lift sand conveying pipe 14, and washing the pollutants on the surface of the gravel 13 under the shear force of the high-speed fluid in the pipe; the air, water and gravel 13 are separated at the outlet of the upper end of the air lift sand conveying pipe 14, and the gravel 13 falls back to the filter layer, and the washing wastewater is collected by the wastewater output device 15 and then flows back to the coagulation assembly tank A; since the filter material of the filter layer at the lower part of the flocculation zone C is continuously sucked away, the filter layer gradually moves downward, and the filter material in the filter layer can be circulated and washed once after a certain period of time. By setting up a wastewater pipe, the flushing wastewater can be returned to the coagulation assembly tank A, effectively saving the cost of manual sand washing.

[0074] A stirring device 3 is respectively arranged inside the coagulation assembly tank A, the first dosing assembly tank F and the second dosing assembly tank G. The bottoms of the coagulation assembly tank A, the contact flocculation assembly tank B, the membrane filtration assembly tank H, the outlet tank I and the intermediate water tank E are all connected with a vent pipe. The bottoms of the contact flocculation assembly tank B and the membrane filtration assembly tank H are also provided with a perforated mud discharge pipe 19. The bottoms of the contact flocculation assembly tank B and the membrane filtration assembly tank H are both tapered structures. With such a design, by adopting a mechanical stirring device 3, the rapid dissolution of the agent is promoted, the cost of the agent is reduced, and the water treatment efficiency is effectively improved. A vent valve is arranged on each vent pipe and the perforated mud discharge pipe 19. By arranging the perforated mud discharge pipe 19 at the bottom of the contact flocculation assembly tank B and the membrane filtration assembly tank H, it is convenient to discharge sand and mud from the inclined tube sedimentation area D of the contact flocculation assembly tank B and the membrane filtration assembly tank H. Specifically, the perforated mud discharge pipe 19 in the contact flocculation assembly tank B is used to discharge the sludge in the inclined tube sedimentation area D and the gravel 13 washed away by the flocculation area C. The leaked gravel 13 can be collected regularly and put into the flocculation area C to replenish the amount of gravel 13 in the flocculation area C; the empty hole mud discharge pipe in the membrane filtration assembly tank H is used to discharge the sludge in the membrane filtration assembly tank H. By setting the bottom of the contact flocculation assembly tank B and the bottom of the membrane filtration assembly tank H as a tapered structure, the bottom of the contact flocculation assembly tank B and the bottom of the membrane filtration assembly tank H form a large slope, which can effectively prevent the sludge from floating up, so that the sludge can gather at the bottom, achieve good sedimentation conditions, and facilitate sludge discharge.

[0075] A method for using the secondary coagulation-ultrafiltration device for dealing with high turbidity comprises the following steps:

[0076] Step 1: Add a corresponding amount of polyaluminium chloride into the first dosing assembly tank F, and add a corresponding amount of potassium permanganate-enhanced ferric chloride coagulant into the second dosing assembly tank G; the dosage of polyaluminium chloride and potassium permanganate-enhanced ferric chloride coagulant in the secondary coagulation is determined by a small test.

[0077] Step 2: Open the first water inlet valve 2 to pass the raw water to be treated, open the fourth water inlet valve 23, so that the coagulation assembly tank A, the contact flocculation assembly tank B and the intermediate water tank E form a circulation system. When the first batch of water enters the intermediate water tank E, close the first water inlet valve 2, and after the polyaluminum chloride coagulant is fully mixed in the coagulation assembly tank A, enter the contact flocculation assembly tank B to complete the first flocculation and the first precipitation, and then enter the coagulation assembly tank A after passing through the intermediate water tank E, and then potassium permanganate reinforced ferric chloride coagulant is fully mixed in the coagulation assembly tank A, and then flow into the contact flocculation assembly tank B to complete the second flocculation and the second precipitation; in the flocculation area C, the gravel 13 acts as a coagulant to adsorb and neutralize the charges on the surface of the suspended particles, promote the adsorption bridging effect between the particles, and the gaps between the gravel 13 particles can provide a bridging effect for the particles to connect with each other. When the gravel 13 particles contact the suspended particles, the suspended particles can be deposited in the gaps between the gravel 13 particles and form aggregates. This bridging effect helps to increase the aggregate size and density of suspended matter, promotes the sedimentation of suspended matter, and improves the removal efficiency of suspended matter.

[0078] The first air pump 9 distributes air to the lower part of the flocculation area C through the air distribution pipe 12, and air and water form an air-water mixture in the air lift sand conveying pipe 14. Since the density of the air-water mixture is much smaller than that of water, the pressure difference inside and outside the pipe drives the air-water mixture to flow from bottom to top through the pipeline at high speed, and forms a low pressure at the lower end of the pipe, sucking the surrounding water and sand into the air lift sand conveying pipe 14, and the pollutants on the surface of the gravel 13 are washed down under the shear force of the high-speed fluid in the pipe; the air, water and gravel 13 are separated at the outlet of the upper end of the air lift sand conveying pipe 14, and the gravel 13 falls back to the filter layer, and the flushing wastewater is collected by the wastewater output device 15 and then returned to the coagulation assembly tank A; since the filter material of the filter layer at the lower part of the flocculation area C is continuously sucked away, the filter layer gradually moves downward, and the filter material in the filter layer can be circulated and washed once after a certain period of time.

[0079] Step three, close the fourth water inlet valve 23, open the third water inlet valve 25, wait for the first batch of treated water in step two to enter the membrane filter assembly tank H, close the third water inlet valve 25, open the fourth water inlet valve 23, and carry out secondary coagulation treatment of the next batch of raw water to be treated; whether the first batch of treated water in step two has basically or completely entered the membrane filter assembly tank H can be judged in two ways. The first way is to design a safety system 0.7 in advance according to the size of the contact flocculation assembly tank B. After opening the third water inlet valve 25 in step three, when the water in the intermediate water tank E is emptied, open the first water inlet valve 2. When 0.7 times the volume is discharged from the contact flocculation assembly tank B, it can be judged that the first batch of treated water has basically entered the membrane filter assembly tank H; the second way is to close the fourth water inlet valve 23 in step three, keep the first water inlet valve 2 closed, and after the water in the intermediate water tank E is completely discharged into the contact flocculation assembly tank B, it can be judged that the first batch of treated water has completely entered the membrane filter assembly tank H.

[0080] Step 4: After the first batch of effluent enters the membrane filtration assembly pool H, it is siphoned into the effluent pool I. The water quality in the effluent pool I stably meets the "Sanitary Standard for Drinking Water" (GB5749-2022).

Claims

1. A method for using a secondary coagulation-ultrafiltration device to deal with high turbidity, characterized in that: A secondary coagulation-ultrafiltration device for dealing with high turbidity is used, which includes a low-drug coagulation-ultrafiltration device, an intermediate water tank (E) and a second dosing assembly tank (G), wherein the low-drug coagulation-ultrafiltration device includes a coagulation assembly tank (A), a contact flocculation assembly tank (B), a membrane filtration assembly tank (H), an outlet tank (I) and a first dosing assembly tank (F), wherein the first dosing assembly tank (F) is connected to the coagulation assembly tank (A) through a pipeline, and the coagulation assembly tank (A) is connected to a first water inlet The contact flocculation assembly tank (B) is provided with a flocculation zone (C) and an inclined tube sedimentation zone (D) which are connected to each other. The upper part of the flocculation zone (C) is connected to the lower part of the inclined tube sedimentation zone (D). The flocculation zone (C) is connected to the coagulation assembly tank (A) through a second water inlet pipe. The membrane filtration assembly tank (H) is connected to the upper part of the inclined tube sedimentation zone (D) through a third water inlet pipe. A membrane aeration system is provided in the membrane filtration assembly tank (H). The outlet of the membrane filtration assembly tank (H) is connected to the outlet tank (I) through an outlet pipe. Valves are arranged on each pipeline to control the on-off of the pipeline; the second dosing assembly tank (G) is connected to the coagulation assembly tank (A) through a pipeline, and the water inlet and water outlet of the intermediate water tank (E) are connected to the upper part of the inclined tube sedimentation area (D) and the upper part of the coagulation assembly tank (A) through the fourth water inlet pipe and the fifth water inlet pipe respectively, and the on-off of the pipeline is controlled by arranging valves on each pipeline; a first water inlet valve (2) is arranged on the first water inlet pipe, a third water inlet valve (25) is arranged on the third water inlet pipe, and a fourth water inlet valve (26) is arranged on the fourth water inlet pipe. Four water inlet valves (23); the first dosing assembly tank (F) is a polyaluminium chloride coagulation dosing assembly tank, and the second dosing assembly tank (G) is a potassium permanganate enhanced ferric chloride coagulation dosing assembly tank; a water inlet distributor (8), gravel (13) and a self-cleaning component for washing the gravel (13) are arranged in the flocculation area (C), the water inlet distributor (8) is arranged in the middle of the flocculation area (C) and is connected to the second water inlet pipe, and the wastewater outlet of the self-cleaning component is connected to the coagulation assembly tank (A) through a wastewater pipe; When dealing with high turbidity water treatment, the following steps are included: Step 1: Add a corresponding amount of polyaluminium chloride into the first dosing assembly tank (F), and add a corresponding amount of potassium permanganate-enhanced ferric chloride coagulant into the second dosing assembly tank (G); Step 2: Open the first water inlet valve (2) to pass the raw water to be treated, open the fourth water inlet valve (23), so that the coagulation assembly tank (A), the contact flocculation assembly tank (B) and the intermediate water tank (E) form a circulation system. When the first batch of water enters the intermediate water tank (E), close the first water inlet valve (2), and after the polyaluminium chloride coagulant is fully mixed in the coagulation assembly tank (A), enter the contact flocculation assembly tank (B) to complete the first flocculation and the first sedimentation, then enter the coagulation assembly tank (A) after passing through the intermediate water tank (E), and then, in the coagulation assembly tank (A), the potassium permanganate-enhanced ferric chloride coagulant is fully mixed, and then flows into the contact flocculation assembly tank (B) to complete the second flocculation and the second sedimentation; Step 3: close the fourth water inlet valve (23), open the third water inlet valve (25), wait for the first batch of treated water in step 2 to enter the membrane filter assembly pool (H), close the third water inlet valve (25), open the fourth water inlet valve (23), and perform secondary coagulation treatment on the next batch of raw water to be treated; Step 4: After the first batch of effluent enters the membrane filtration assembly tank (H), it enters the effluent tank (I) through siphoning.

2. The method of use according to claim 1, characterized in that: The contact flocculation assembly tank (B) comprises a main shell (101), a baffle (102) and a partition (103), wherein the partition (103) and the baffle (102) are vertically offset and fixed in parallel in the main shell (101), a channel is formed between the baffle (102) and the partition (103), the top end of the channel is connected to the flocculation zone (C), and the bottom end of the channel is connected to the inclined tube sedimentation zone (D).

3. The method of use according to claim 1, characterized in that: A stirring device (3) is respectively arranged inside the coagulation assembly tank (A), the first dosing assembly tank (F) and the second dosing assembly tank (G); the bottoms of the coagulation assembly tank (A), the contact flocculation assembly tank (B), the membrane filtration assembly tank (H), the water outlet tank (I) and the intermediate water tank (E) are all connected with a vent pipe; the bottoms of the contact flocculation assembly tank (B) and the membrane filtration assembly tank (H) are also provided with a perforated mud discharge pipe (19); the bottoms of the contact flocculation assembly tank (B) and the membrane filtration assembly tank (H) are both of a tapered structure.

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