Ultrafiltration device for treating raw water in combination with synchronous flocculation

Abstract

The utility model relates to the technical field of water treatment, in particular to an ultrafiltration device for treating raw water by combining synchronous flocculation. Comprising an ultrafiltration unit and a synchronous flocculation unit, the ultrafiltration unit comprises an ultrafiltration membrane tank, an ultrafiltration membrane assembly, a micro-vortex fluidized filler and an aeration unit; raw water to be treated is injected into the ultrafiltration membrane tank, and an adsorbent is added to adsorb the raw water to be treated; a PVDF (Polyvinylidene Fluoride) ultrafiltration membrane assembly or a plate-type and tubular ceramic ultrafiltration membrane is arranged in the ultrafiltration membrane pool, the water outlet end of the ultrafiltration membrane assembly is connected with a water producing pump through a pipeline, the water outlet end of the water producing pump is connected with a backwashing water tank and produced water, and a certain amount of produced water is stored for backwashing during operation; during backwashing, ultrafiltration produced water in a backwashing water tank is used and is pumped back to the membrane assembly through a backwashing pump; the aeration unit is connected with the ultrafiltration membrane tank and is used for aeration cleaning during physical backwashing; the synchronous flocculation unit comprises a flocculant metering pump and a mechanical stirrer. According to the device, the service life of the membrane can be prolonged, the filtering effect is improved, and meanwhile, the follow-up maintenance frequency and cost are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment, in particular to an ultrafiltration device for synchronous flocculation combined with raw water treatment. Background Art

[0002] Compared with conventional civil engineering water plants, integrated water treatment equipment has the advantages of small footprint, less impact from topography, low investment price, simple operation and management, low operating cost and stable effect. In addition, ultrafiltration technology has been widely used due to its excellent turbidity removal effect and biosafety control effect.

[0003] Currently, water treatment generally relies on conventional integrated coagulation-sedimentation-filtration processes, such as those used in SDJ, LEJI, and LEGS water purifiers. Some equipment has optimized the process through enhanced coagulation and other methods. However, due to the relatively small scale of these integrated systems and the limited time required for the water purification process, their ability to remove turbidity, microbial contaminants, and other contaminants is limited. Consequently, these short-process integrated systems generally exhibit poor water treatment efficiency. Consequently, there is an urgent need for equipment that can improve water purification efficiency while shortening the overall process. Utility Model Content

[0004] The purpose of this utility model is to improve the water treatment efficiency of short-process integrated equipment and provide an ultrafiltration device for treating raw water with synchronous flocculation. It adopts hollow fiber membrane or ceramic membrane as the core, and simultaneously sets online flocculation in the submerged membrane pool to reduce the pollution of the incoming water to the membrane and improve the water purification efficiency, while shortening the length of the overall process flow to achieve the goal of meeting the raw water treatment and water supply requirements.

[0005] The purpose of the utility model is achieved through the following technical solutions:

[0006] A device for treating raw water by combining simultaneous flocculation and ultrafiltration, characterized in that it comprises an ultrafiltration unit and a simultaneous flocculation unit; the ultrafiltration unit comprises an ultrafiltration membrane pool, an ultrafiltration membrane assembly, a micro-vortex fluidized filler and an aeration unit; raw water to be treated is injected into the ultrafiltration membrane pool, and an adsorbent is added to adsorb the raw water to be treated; a PVDF or ceramic ultrafiltration membrane assembly is provided in the ultrafiltration membrane pool, the outlet end of the ultrafiltration membrane assembly is connected to a water production pump via a pipeline, the outlet end of the water production pump is connected to a backwash water tank and produced water, and a certain amount of produced water is stored during operation for backwashing; the backwash water tank is connected to the backwash pump, and the ultrafiltration produced water in the backwash water tank is used during backwashing, which is returned to the membrane assembly pool body by the backwash pump and then enters the ultrafiltration membrane pool for cleaning; the aeration unit is connected to the ultrafiltration membrane pool and performs aeration cleaning during physical backwashing; the simultaneous flocculation unit comprises a flocculant metering pump and a mechanical agitator; water is introduced into the ultrafiltration membrane pool via the raw water pump, and a mechanical agitator is provided at the bottom of the ultrafiltration membrane pool.

[0007] Furthermore, the flocculant is basic aluminum chloride PAC, the molecular formula of which is [Al2(OH)nCl 6-n ]m, where m≤10, n=3~5; the addition concentration is 5mg / L or other addition amount.

[0008] Furthermore, a micro-vortex fluidized filler with a certain filling density is provided in the pool body. The filler size is not limited to 2-20 cm. A vortex form combining hollowness and flow channels is provided inside. The filler can be suspended or floated and fluidized in the ultrafiltration membrane pool 1 under the action of water flow to promote the flocculation of the turbidity in the pool body, which is conducive to the precipitation and scrubbing of pollutants attached to the ultrafiltration surface, forming surface vibration and shear force.

[0009] Furthermore, the ultrafiltration membrane assembly is a hollow fiber membrane or a ceramic ultrafiltration membrane with an average pore size of 0.05 μm and is made of PVDF or ceramic.

[0010] Furthermore, the aeration unit includes an aeration pump, which passes gas into the ultrafiltration membrane pool through one or more pipelines, and the total aeration typical intensity is 10L / min / m 2 ; The aeration effect promotes the movement of suspended vortex packing, increases the chance of collision with the ultrafiltration membrane, and reduces the formation of mud cake layer on the membrane surface.

[0011] Furthermore, the ultrafiltration membrane assembly is fixed about 5-10 cm below the liquid surface of the ultrafiltration membrane pool, and adopts an outside-to-inside filtration mode.

[0012] Furthermore, a water production pump and a backwash pump are respectively provided for the operation process of the ultrafiltration system, for the water production process and the backwash process respectively. The backwash has the backwash functions of high-speed flash flushing and surface scrubbing effect produced by the fluidization of suspended fillers.

[0013] Furthermore, the water treatment device performs air-water coordinated backwashing every time it operates for a period of time, and the backwash flux is 40 to 60 LMH.

[0014] Furthermore, after each cycle is completed, a concentration discharge step is performed to discharge 1 / 3 to 1 / 5 of the raw water in the ultrafiltration membrane pool; after several cycles of operation, the ultrafiltration membrane pool is completely emptied to control the concentration of raw water pollutants in the ultrafiltration membrane pool.

[0015] Furthermore, the device is connected to a data recording and automatic control unit and is controlled by a PLC system; the data recording and automatic control unit includes a liquid level control system for detecting the liquid level height in the ultrafiltration membrane pool, the liquid level control system is connected to the raw water pump, and a pressure sensor is provided on the pipe at the water outlet of the membrane assembly. The pressure sensor is connected to the computer through a communication controller, and the system automatically controls the switch and start and stop status of each valve and water pump in the device according to feedback.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This solution employs micro-vortex fluidized packing with a specific packing density within the ultrafiltration membrane tank. Its internal structure allows the packing to suspend, float, and fluidize within the tank under the influence of water flow. This design promotes flocculation and scrubs the surface of the ultrafiltration membrane, effectively reducing contaminant deposition on the membrane surface. An aeration unit introduces air into the ultrafiltration membrane tank via an aeration pump, increasing the dissolution of gas in the water. This promotes the movement of the suspended vortex packing, increases the chance of collision with the ultrafiltration membrane, and reduces the formation of a cake layer on the membrane surface. This physical backwashing also helps maintain the permeability of the ultrafiltration membrane. The coordinated air-water backwash effectively cleans the ultrafiltration membrane surface, reduces the accumulation of membrane contaminants, and improves water purification efficiency. The concentration discharge step helps control the contaminant concentration within the ultrafiltration membrane tank and reduce contaminant accumulation. The automated control system is connected to the data recording and automatic control unit and is controlled by a PLC system. Devices such as the liquid level control system and pressure sensors monitor and control the operating status of the ultrafiltration membrane tank in real time. This automated control system precisely controls the operation of the system, ensuring the accuracy and effectiveness of each operation.

[0018] This new water treatment device uses simultaneous flocculation to reduce membrane contamination by incoming water and improve water purification efficiency. Compared to conventional coagulation-sedimentation-filtration water purification processes, simultaneous flocculation-ultrafiltration shortens the overall process flow while ensuring effective removal of turbidity and microbial contaminants. The device boasts a simple structure, is less susceptible to membrane fouling, occupies a small footprint, and is less affected by topography. For low-turbidity and low-organic contamination in raw water, simultaneous flocculation-ultrafiltration can effectively control effluent quality and exhibits excellent response characteristics to extreme water quality conditions. It features a small investment, easy production and installation, low operating and maintenance costs, automated control, and ease of retrofit and upgrade. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a specific embodiment of the utility model;

[0020] Figure 2 This is a diagram of the effluent turbidity of certain embodiments of the present utility model;

[0021] Figure 3 UV in different types of water 254 and COD Mn Content diagram;

[0022] Figure 4 This is a graph showing changes in TMP during direct ultrafiltration and simultaneous flocculation ultrafiltration.

[0023] The numbers in the figure are: 1. Membrane tank; 2. Flocculant metering pump; 3. Water production pump; 4. Backwash water tank; 5. Aeration pump; 6. Mechanical agitator; 7. Raw water pump; 8. Liquid level control system; 9. Valve; 10. Data recording and automatic control unit; 11. Pressure sensor; 12. Communication controller; 13. Backwash pump. DETAILED DESCRIPTION

[0024] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.

[0025] like Figure 1 An ultrafiltration device that uses synchronous flocculation to treat raw water consists of an ultrafiltration unit, a synchronous flocculation unit, and a data recording and automatic control unit. The ultrafiltration unit includes a membrane pool 1. The raw water to be treated is injected into the membrane pool 1. The flocculant is pumped in synchronously with the water intake through the flocculant metering pump 2. An ultrafiltration membrane assembly is provided in the membrane pool 1. The outlet end of the membrane assembly is connected to the water production pump 3 through a pipeline. The outlet end of the water production pump 3 is connected to the backwash tank 4 and the produced water. After the water production cycle is completed, the backwash pump uses the produced water in the backwash tank 4 for physical backwashing. At the same time, the aeration pump 5 starts working and passes gas into the membrane pool 1 through one or more pipelines. The total aeration intensity is 10L / min / m 2 , and perform coordinated backwashing of air and water. The synchronous flocculation unit is connected to the membrane pool 1. In addition to the flocculant metering pump 2, it also includes a mechanical agitator 6. During the water production process, the mechanical agitator 6 continues to operate to improve the flocculation effect. The raw water is introduced into the membrane pool 1 through the raw water pump 7. During the filtration process, the start and stop and the opening and closing of the corresponding valves are controlled by the feedback of the liquid level control system 8. After each cycle, the pus drainage process is controlled by the emptying pipe and valve 9. The data recording and automatic control unit 10 controls the start and stop and opening and closing of each water pump and the corresponding valve, and is respectively connected to the liquid level control system 8 and the pressure sensor 11 on the inlet and outlet pipes. The pressure sensor 11 is connected to the computer through the communication controller 12.

[0026] The flocculant used was basic aluminum chloride (PAC) at a concentration of 5 mg / L. Aeration was continued during the physical backwash process at an intensity of 10 L / min.

[0027] The ultrafiltration membrane assembly was fixed 6 cm below the liquid level in membrane tank 1. Filtration was performed from the outside in, with the membrane outlet connected to a production water pump via a pipe. The production water pump provided filtration power. A separate backwash pump drew water from the backwash tank for the backwash step. During the experiment, the constant flow filtration flux was 40 LMH. A 90-second air-water backwash was performed every 150 minutes of operation, with a backwash intensity of 40 LMH.

[0028] Figure 2 The figure shows the turbidity of the effluent of the embodiment. It can be seen from the figure that the turbidity of the effluent of the device can be stabilized below 0.05, and the turbidity removal rate reaches 98.8%. Figure 3 This is the organic matter index diagram. The device has a UV 254 The removal rates of chlorine and permanganate index reached 14.84% and 21.91%, respectively. Figure 4 The graphs of the transmembrane pressure difference during direct ultrafiltration and simultaneous flocculation ultrafiltration are shown in Figure 2. The experimental results show that simultaneous flocculation can effectively improve the operating stability of the ultrafiltration device.

[0029] In summary, this solution improves membrane fouling control by injecting raw water to be treated into the membrane tank and simultaneously adding a quantitative flocculant and suspended vortex sphere filler to the tank for micro-flocculation. The membrane tank is equipped with an organic ultrafiltration membrane assembly, which filters the raw water and is connected to the outlet system via a pipe to achieve water purification. The filtration process is completed by suction filtration using a centrifugal pump. The membrane assembly is also connected to a backwash centrifugal pump for physical backwashing. The aeration unit is connected to air pressure and aeration is carried out through aeration holes located at the bottom of the membrane assembly to clean the ultrafiltration membrane. To address the low turbidity and stable temperature characteristics of certain raw water, the device uses a PVDF organic ultrafiltration membrane as the core, and adopts a flocculant for simultaneous flocculation and suspended vortex sphere filler. This not only promotes flocculation, but also impacts the ultrafiltration membrane surface, reducing contamination of the membrane by the incoming water and improving water purification efficiency. This also shortens the overall process flow to meet water purification goals.

[0030] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of protection of the present invention.

Claims

1. A simultaneous flocculation combined with ultrafiltration device for treating raw water, characterized in that: The invention comprises an ultrafiltration unit and a synchronous flocculation unit; the ultrafiltration unit comprises an ultrafiltration membrane pool (1), an ultrafiltration membrane assembly, a micro-vortex hollow fluidized filler with a diameter of 2 to 20 cm, and an aeration unit; the ultrafiltration membrane pool (1) is provided with an ultrafiltration membrane assembly, the water outlet end of the ultrafiltration membrane assembly is connected to a water production pump (3) through a pipeline, the water outlet end of the water production pump (3) is connected to a backwash water tank (4) and produced water, and a certain amount of produced water is stored during operation for backwashing; the backwash water tank (4) is connected to the backwash pump (13), the aeration unit is connected to the ultrafiltration membrane pool (1), and aeration cleaning is performed during physical backwashing; the synchronous flocculation unit comprises a flocculant metering pump (2) and a mechanical stirrer (6); water is introduced into the ultrafiltration membrane pool (1) through a raw water pump (7), and a mechanical stirrer (6) is provided at the bottom of the ultrafiltration membrane pool (1).

2. The simultaneous flocculation combined with ultrafiltration device for treating raw water according to claim 1, characterized in that: A micro-vortex hollow fluidized filler with a certain filling density is provided in the pool body. The filler size is not limited to 2-20 cm. A vortex form combining a hollow and a flow channel is provided inside. The filler can be suspended or floated and fluidized in the ultrafiltration membrane pool (1) under the action of water flow to promote flocculation and scrub pollutants attached to the ultrafiltration surface, thereby forming surface vibration and shear force.

3. The simultaneous flocculation combined with ultrafiltration device for treating raw water according to claim 1, characterized in that: The ultrafiltration membrane component is a hollow fiber membrane or a ceramic ultrafiltration membrane, and its average pore size is 0.05 μm.

4. The simultaneous flocculation combined with ultrafiltration device for treating raw water according to claim 1, characterized in that: The aeration unit includes an aeration pump (5) that passes gas into the ultrafiltration membrane pool (1) through one or more pipelines. The total aeration typical intensity is 10L / min / m 2 , which can achieve 10s ultra-high intensity instantaneous flash aeration for vibration.

5. The simultaneous flocculation combined with ultrafiltration device for treating raw water according to claim 1, characterized in that: The ultrafiltration membrane assembly is fixed 5-10 cm below the liquid level of the ultrafiltration membrane pool (1).

6. The simultaneous flocculation combined with ultrafiltration device for treating raw water according to claim 1, characterized in that: A water production pump (3) and a backwash pump (13) are respectively provided for the operation process of the ultrafiltration system, and are used for the water production process and the backwash process respectively. The backwash has the backwash function of high-speed flash flushing and surface scrubbing effect generated by the fluidization of suspended fillers.

7. The simultaneous flocculation combined with ultrafiltration device for treating raw water according to claim 1, characterized in that: The device is connected to a data recording and automatic control unit (10) and is controlled by a PLC system; the data recording and automatic control unit (10) includes a liquid level control system (8) for detecting the liquid level height in the ultrafiltration membrane pool (1); the liquid level control system (8) is connected to a raw water pump (7); a pressure sensor (11) is provided on the pipe at the outlet end of the membrane assembly; the pressure sensor (11) is connected to a computer via a communication controller (12); and the system automatically controls the switch and start / stop status of each valve (9) and the water pump in the device according to feedback.

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