Membrane process integrated water purification system

Abstract

The application discloses a membrane integrated water purification system, which combines filter tanks, breathing ceramic filter material tanks and MCR technology, can effectively remove pollutants in water bodies, can also adapt to water sources with high turbidity, has the advantages of improving impact resistance, reducing filter membrane blockage, reducing investment and energy consumption, reducing land occupation area and improving water quality, etc.

Description

Technical Field

[0001] This application belongs to the field of water treatment technology, and in particular relates to an integrated membrane water purification system. Background Technology

[0002] In rural areas, most surface and groundwater sources have low turbidity. The particulate matter in low-turbidity water is small and evenly dispersed, making it difficult for flocs to accumulate and form sediment. Furthermore, the low concentration of suspended solids in low-turbidity water results in low particle velocity and a low probability of particle collision, which is unfavorable for floc formation. Any flocs that do form are easily broken down by coagulation and agitation. When treating low-turbidity source water using conventional water treatment processes, it is usually necessary to add higher levels of flocculants and / or additional microparticle nuclei.

[0003] In existing technologies, column ultrafiltration can effectively remove bacteria, viruses, pathogenic protozoa and particulate pollutants from water and is used in stable low-turbidity water sources. However, when encountering water sources with high turbidity due to rain or other reasons, it is easy to cause ultrafiltration membrane fouling and a significant decrease in water flux. Summary of the Invention

[0004] The purpose of this application is to overcome the deficiencies of existing technologies and provide a water purification system and method that can adapt to water sources with high turbidity, thereby improving shock resistance, reducing investment and energy consumption, and improving the quality of produced water.

[0005] This application provides an integrated membrane water purification system, comprising an interconnected filtration system and a membrane system. The filtration system includes a filter tank and a respirable ceramsite filter media tank. The membrane system includes an MCR membrane tank, a product water tank, and a dosing device. The filter tank includes a first filtration structure, an inlet, an air inlet, and a first overflow outlet. The first filtration structure, inlet, and air inlet are located at the lower part of the filter tank, and the first overflow outlet is located at the upper part of the filter tank, communicating with the inlet of the respirable ceramsite filter media tank. The respirable ceramsite filter media tank includes a second filtration structure and a collection outlet. The collection outlet is located at the bottom of the second filtration structure and communicates with the inlet of the MCR membrane tank. The product water outlet of the MCR membrane tank is connected to the inlet of the product water tank, and the dosing device adds chemicals to the product water tank.

[0006] Preferably, the membrane-integrated water purification system includes at least two layers, with the filtration system layer located on top of the membrane system layer.

[0007] Preferably, the second filtration structure includes breathable ceramic filter media, which satisfies at least one of the following characteristics:

[0008] The filling degree of the breathable ceramic filter media in the second filter structure is 35-60%;

[0009] The porosity of the breathable ceramic filter media is 35-80%;

[0010] The particle size range of the breathable ceramic filter media is 5–30 mm; the density after water saturation is 1020–1100 kg / m³. 3 .

[0011] Preferably, the bottom of the first filter structure is provided with a support plate, and the height of the support plate near the breathing ceramic filter media pool is higher than the height away from the breathing ceramic filter media pool, and the angle formed by the height difference is 3 to 15°.

[0012] Preferably, the first filter structure comprises a filter media layer, an intermediate layer, and a support layer from top to bottom, the support layer being placed on the support plate, and the first filter structure satisfies at least one of the following characteristics:

[0013] The filter media layer includes quartz sand;

[0014] The intermediate layer comprises fine pebbles;

[0015] The diameter of the fine pebbles is 5-10 mm;

[0016] The support layer comprises coarse pebbles;

[0017] The coarse pebbles have a diameter of 20–30 mm.

[0018] Preferably, the bottom of the second filter structure is an inclined support with high ends and low middle, the inclined support is used to support the breathing ceramic filter media, the lowest point of the inclined support is connected to the water collection port, and the water collection port is connected to the water inlet of the MCR membrane tank.

[0019] Preferably, the water collection port is connected to the water inlet of the MCR membrane tank via a vertical pipe.

[0020] Preferably, the inlet of the breathing ceramsite filter tank is provided with a water distributor, which is composed of at least one inverted conical groove, and the bottom of the inverted conical groove has a drain hole.

[0021] Preferably, the MCR membrane tank includes a suction system, a pulse aeration device and at least one set of membrane modules, the pulse aeration device being disposed below the membrane modules, and the suction system being used to suction gas and / or water from the membrane modules (11).

[0022] Preferably, the MCR membrane pool satisfies at least one of the following characteristics:

[0023] The membrane module is installed in the MCR membrane tank in a detachable plug-in manner;

[0024] The membrane module includes hollow fiber membrane filaments, with the two ends of the hollow fiber membrane filaments being the upper and lower ends of the filtered water outlet, respectively. The upper and lower ends of the filtered water outlet are connected to a water collection device, and the outlet of the water collection device is the product water outlet of the MCR membrane tank.

[0025] Preferably, the water production tank is equipped with a testing instrument for monitoring the water quality of the water effluent from the water production tank.

[0026] Compared with existing technologies, this application has the following significant advantages:

[0027] 1. This application combines a filter bed, a breathing ceramic filter media tank and MCR technology, which can effectively remove pollutants from water bodies, while also being able to adapt to water sources with high turbidity, thereby improving the impact resistance, reducing filter membrane fouling, reducing investment and energy consumption, reducing the footprint, and improving the quality of produced water.

[0028] 2. The membrane integrated water purification system adopts an upper and lower layer structure, which reduces the floor space, utilizes the high water level difference to save energy, reduces water flow fluctuations, and improves the removal of suspended solids (SS).

[0029] 3. The filter adopts bottom side inlet, diagonally opposite the first overflow outlet, to increase the water flow distance and stability, and improve the SS removal efficiency. The first filtration structure of the filter has a filter media layer, an intermediate layer and a support layer. Due to the weight difference between the first filtration structures, a relatively uniform air cushion layer is formed. Combined with air-water flushing, it ensures uniform water and air distribution. The layers do not mix and allow for multi-layer filter media combinations, making flushing easy to achieve the best effect. The multi-layer filter media has a strong dirt holding capacity, stable effluent water quality, long flushing cycle and low energy consumption.

[0030] 4. The overflow water is introduced into the breathing ceramsite filter tank through the water distributor, which increases the contact between water and air, increases the dissolved oxygen in the water, and thus increases the oxygen absorption of the breathing ceramsite, improves the biochemical effect, and greatly improves the removal rate of organic pollutants.

[0031] 5. MCR membrane tanks have advantages such as simple structure, easy operation, easy expansion, addition of components, and lower energy consumption than traditional processes. MCR membranes remove almost all bacteria and suspended solids (SS) in the water, ensuring the quality of the produced water. In addition, the use of pulse aeration devices with large-pore pulse aeration provides large flushing and oscillation, resulting in high decontamination efficiency and energy savings. Attached Figure Description

[0032] Figure 1 This is a front view of an integrated membrane water purification system according to this application;

[0033] Figure 2 This is a rear view of an integrated membrane water purification system according to this application;

[0034] Figure 3This is a schematic diagram of the MCR membrane cell structure containing two sets of membrane modules according to this application;

[0035] Figure 4 This is a schematic diagram of the MCR membrane cell structure containing one set of membrane modules according to this application;

[0036] Figure 5 This is a floor plan of the layer where the filtering system of this application is located;

[0037] Figure 6 This is a plan view of the layer containing the membrane system of this application.

[0038] Figure label:

[0039] 1-First filtration structure, 2-Second filtration structure, 3-Air inlet, 4-Water inlet, 5-First overflow outlet, 6-Water distributor, 7-Water collection outlet, 8-Vertical pipe, 9-Water inlet of MCR membrane tank, 10-Discharge outlet, 11-Second overflow outlet, 12-Water outlet, 13-Third overflow outlet, 14-Discharge outlet, 15-Membrane module, 16-Pulse aeration device. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0041] As used herein, "an embodiment" or "an embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. The content of this application can be more readily understood by referring to the following detailed description of preferred embodiments and included examples. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of conflict, the definitions in this specification shall prevail.

[0042] For the purposes of the detailed description below, it should be understood that various alternative variations and sequences of steps may be employed in this application, unless expressly stated otherwise. Furthermore, except in any operational instance, or otherwise indicated, all figures representing the amounts of ingredients used, for example, in the specification and claims, should be understood to be modified in all cases by the term “about.” Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximate values ​​varying according to the desired performance to be obtained in this application. At least not in an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be interpreted at least according to the number of reported significant figures and by applying ordinary rounding techniques.

[0043] Although the numerical ranges and parameters described in this application are approximate, the values ​​listed in the specific examples are reported as precisely as possible. However, any numerical value inherently contains some error that is necessarily caused by the standard deviation found in their respective test measurements.

[0044] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. For example, a specified range from “1 to 10” should be considered to include any and all subranges between the minimum value 1 and the maximum value 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0045] Before providing a further detailed description of the embodiments of this application, the nouns and terms involved in the embodiments of this application will be explained, and the nouns and terms involved in the embodiments of this application shall be interpreted as follows.

[0046] MCR: Membrane Chemical Reactor or Membrane Coagulation Reactor.

[0047] This application provides an integrated membrane-based water purification system, referencing... Figure 1-2 As shown, the system includes an interconnected filtration system and a membrane system. The filtration system comprises a filter bed and a breathing ceramsite filter media tank. The membrane system includes an MCR membrane tank, a product water tank, and a dosing device. The product water inlet of the MCR membrane tank is connected to the inlet of the product water tank, and the dosing device is used to add chemicals to the product water tank. This application combines filter beds, breathing ceramsite filter media tanks, and MCR technology, which can effectively remove pollutants from water bodies. It can also adapt to water sources with high turbidity, achieving advantages such as improved shock resistance, reduced filter membrane fouling, lower investment and energy consumption, and improved product water quality. Furthermore, MCR can replace the traditional sand filtration + carbon filtration process, resulting in better effluent. It can filter out bacteria, viruses, colloids, and small molecular weight particles, can be used at room temperature, and offers reliable filtration performance, high precision, and can achieve separation, concentration, purification, and classification without the need for chemical dosing.

[0048] The filter includes a first filtration structure 1, a water inlet 4, an air inlet 3, and a first overflow outlet 5. The first filtration structure 1, the water inlet 4, and the air inlet 3 are located at the lower part of the filter, and the first overflow outlet 5 is located at the upper part of the filter. The first overflow outlet 5 is connected to the inlet of the breathing ceramic filter media tank. On the one hand, the water inlet 4 and the first overflow outlet 5 are arranged diagonally to increase the water flow distance and stability, thereby improving the SS removal efficiency. On the other hand, the water inlet 4 and the air inlet 3 at the lower part of the filter can form an air-water flushing method, increasing the contact and exchange time between water and air in the filtration structure 1.

[0049] Furthermore, the filter bed is also equipped with a discharge port 14 for discharging water from the filter bed.

[0050] The breathing ceramic filter media tank includes a second filtration structure 2 and a water collection port 7. The water collection port 7 is located at the bottom of the second filtration structure 2 and is connected to the water inlet 9 of the MCR membrane tank. When water flows through the second filtration structure 2, it can trap suspended solids with smaller particle sizes, providing better influent water quality for the membrane tank.

[0051] In some embodiments, the membrane integrated water purification system of this application includes at least two layers, with the filtration system layer located on top of the membrane system layer. This can further reduce the system's footprint, and can also utilize the high-level water flow to save energy, reduce water flow fluctuations, and improve the removal of suspended solids (SS).

[0052] Furthermore, the bottom of the first filter structure 1 is provided with a support plate. The height of the support plate near the breathing ceramic filter media pool is higher than the height away from the breathing ceramic filter media pool. The resulting height difference makes the support plate form a slope of 3 to 15° at the bottom of the first filter structure, which reduces the resistance when the water flows into the filter pool and increases the contact area between the water in the filter pool and the first filter structure 1.

[0053] Specifically, the slope of the support plate can be 3, 6, 7, 8, 9, 10, 12, 13, or 15°.

[0054] In some embodiments, the first filter structure 1 is placed on a support plate and consists of a filter media layer, an intermediate layer, and a support layer from top to bottom. The filter media layer includes quartz sand; the intermediate layer includes fine pebbles with a diameter of 5-10 mm; and the support layer includes coarse pebbles with a diameter of 20-30 mm. The weight difference between the layers forms a relatively uniform air cushion layer, ensuring more uniform water and air distribution. Furthermore, the multi-layer filter media combination allows for a longer rinsing cycle, making rinsing easier to achieve optimal results. Additionally, the multi-layer filter media has a strong dirt-holding capacity, resulting in stable effluent quality and lower energy consumption.

[0055] In some embodiments, the bottom of the second filter structure 2 is an inclined support that is higher at both ends and lower in the middle. The two ends of the inclined support are respectively set on the side walls on both sides of the breathing ceramic filter media tank. The lowest point of the inclined support is connected to the water collection port 7, and the water collection port 7 is connected to the water inlet 9 of the MCR membrane tank. The inclined support has a stronger load-bearing capacity and can also collect water flow. Specifically, the inclination angle from the end of the inclined support to the lowest point is in the range of 3 to 15°.

[0056] In some embodiments, the support plate and / or inclined support are provided with aeration holes to enhance the contact and exchange of water and air in the filter.

[0057] The second filtration structure 2 also includes breathable ceramic filter media placed on an inclined support. This breathable ceramic filter media features better permeability, higher hardness, rough surface, numerous micropores, high porosity, large specific surface area, low water flushing energy consumption, and low head loss, effectively trapping most suspended solids with smaller particle sizes. Specifically, the filling density of the breathable ceramic filter media in the second filtration structure is 35-60%, the porosity is 35-80%, the particle size range is 5-30 mm, and the density after water saturation is 1020-1100 kg / m³. 3 After absorbing water, the density of the breathing ceramic particles is slightly higher than that of water. This allows them to float to the surface during backwashing with low-pressure water, thus improving the exchange efficiency of water and air within the breathing ceramic particle filter media.

[0058] Furthermore, the bottom of the second filter structure 2, that is, above the inclined support, can also be supported by pebbles, which makes it easier for the second filter structure 2 to discharge water.

[0059] Furthermore, at the inlet of the breathing ceramsite filter tank, one end of a water distributor 6 is connected to the first overflow port 5, and overflow water flows from the first overflow port 5 into the water distributor 6. The overflow water enters the breathing ceramsite filter tank through the water distributor 6, increasing the contact between water and air, increasing the dissolved oxygen in the water to enhance oxygen absorption by the breathing ceramsite, improving the biochemical effect, and thus greatly improving the removal rate of organic pollutants. The water distributor 6 consists of at least one inverted conical groove, with a drain hole at the bottom of the inverted conical groove. Specifically, 2-5 inverted conical grooves can be set in the water distributor 6.

[0060] In some embodiments, the water collection port 7 is connected to the water inlet 9 of the MCR membrane tank via a vertical pipe 8. The MCR membrane tank includes a suction system, a pulse aeration device 16, and at least one set of membrane modules 15. The pulse aeration device 16 is located at the bottom of the membrane module 15, used to flush the surface of the membrane fibers, thereby cleaning the membrane by causing the membrane fibers to oscillate and the fouling particles to detach. A permeate port is located at the top of the membrane module 15, and the permeate port is connected to the permeate tank. The membrane module 15 is connected to the pulse aeration device 16 using a quick-connect installation method, which allows for easy disassembly, maintenance, and replacement. The suction system is connected to the membrane module 15 and is used to suction gas and / or water from the membrane module 15.

[0061] Specifically, the membrane module 15 includes hollow fiber membrane filaments and a water collection device. The hollow fiber membrane filaments can produce high-quality filtered water. The membrane module contains thousands of PVDF hollow fiber membrane filaments. The two ends of the membrane filaments are sealed with epoxy resin and polyurethane. The sealing openings at the top and bottom ends form the upper and lower ends of the filtered water from the membrane filaments. The upper and lower ends are respectively connected to the water collection device, or either the upper or lower end can be connected to the water collection device. This allows the inner cavity of the hollow structure of the membrane filaments to be connected to one end of the water collection device. The other end of the water collection device is also provided with a product water outlet, which is connected to the product water tank.

[0062] In some embodiments, reference Figure 3-4 As shown, one or more membrane modules 15 can be installed in the MCR membrane tank.

[0063] Furthermore, the MCR membrane tank is equipped with a suction system. This system causes the gas-water mixture to flow upwards within the membrane tank, creating cross-flow on the membrane surface. This cross-flow continuously washes the membrane surface, preventing the deposition of solid particles. The filtered permeate is pumped from inside the hollow fiber membrane to the collection pipe and then transported to the permeate tank. Impurities in the water are retained in the membrane tank, and the concentrated turbid liquid is continuously or periodically discharged from the membrane tank's discharge port 10. The entire treatment process can be controlled and operated automatically via PLC.

[0064] Furthermore, the MCR membrane tank is also equipped with a second overflow port 11.

[0065] In some embodiments, after the permeate enters the product water tank, it is sterilized by sodium hypochlorite solution in the dosing device to generate product water, which is then discharged from the outlet 12 at the bottom of the product water tank.

[0066] The dosing device for the product water tank and the aeration blower for the pulse aeration device 16 can be installed in the equipment room of the membrane system layer.

[0067] Furthermore, a third overflow outlet 13 is provided at the top of the product water tank to ensure that the liquid level in the product water tank is maintained within a suitable range.

[0068] The membrane-based integrated water purification system described in this application integrates and optimizes technologies such as overflow filter, breathing ceramic filter media for filtration and impurity removal, combined air-water flushing, and membrane water treatment. This significantly improves the water output capacity of the integrated water purification equipment, extends the water output cycle, enhances its resistance to shock, solves filter head clogging, reduces investment and energy consumption, minimizes floor space, and improves the quality of the produced water.

[0069] The preparation method of the respirable ceramsite filter media of this application includes the following steps:

[0070] S1: Provide raw materials and mix them to form a slurry, said raw materials including stone powder, quicklime powder, gypsum powder, foaming agent, ceramic reinforcing agent, cement and water;

[0071] S2: The slurry is foamed and shaped at a preset temperature to form a breathable ceramic material; specifically, the preset temperature is 135-145℃;

[0072] S3: The breathing ceramic material is crushed into granular filter material and then sieved to obtain the breathing ceramic granular filter material.

[0073] In some embodiments, the composition ratio of the slurry is: 25-45 parts stone powder, 15-35 parts quicklime powder, 5-15 parts gypsum powder, 0.5-15 parts foaming agent, 0.3-1 part ceramic reinforcing agent, 6-12 parts cement and 2-5 parts water.

[0074] In some embodiments, the porosity of the breathable ceramic filter media prepared in this application is 35-80%, the open porosity is 60-90%, and the particle size range of the breathable ceramic filter media is 5-30 mm.

[0075] The breathable ceramic filter media prepared in this application has a porous structure. After saturation with water, its density is slightly higher than that of water, allowing it to float to the surface during low-pressure backwashing, thus improving the exchange of water and air within the open pores. The porous structure consists of spherical or interconnected spherical particles formed by foaming with a foaming agent, distributed throughout the ceramic particles in a foaming manner. This makes the breathable ceramic particles resemble a semi-rigid foam sponge, enhancing their breathability.

[0076] The following preferred embodiments of this application are listed to further describe the method of using an integrated membrane water purification system of this application.

[0077] Example 1

[0078] S1: Filter bed filtration: Air enters through inlet 3 at a speed of 450m 3The water is purged into the filter tank at a flow rate of 62T / hour. The water flows into the bottom of the filter tank from the inlet 4 at a flow rate of 62T / hour. The water flows through the first filter structure 1 of the filter tank. The first filter structure 1 is provided with a quartz sand filter media layer, a fine pebble intermediate layer with a diameter of 5-7mm, and a coarse pebble support layer with a diameter of 20-25mm from top to bottom. The bottom surface of the coarse pebble support layer has a 10-degree support plate. The water flows from the bottom inlet 4 upward to form overflow water. The overflow water enters the breathing ceramic filter media tank from the first overflow outlet 5.

[0079] S2: Filtration in the Breathing Ceramsite Filter Tank: Overflow water enters the water distributor of the breathing ceramsite filter tank. The water distributor has 3 sets of inverted conical grooves, each with several drainage holes at the bottom. The overflow water exits through these drainage holes, passes through the second filter structure 2, and then exits through the water collection port 7 at the bottom of the second filter structure 2, flowing into the MCR membrane tank. The inclined support of the second filter structure 2 has an inclination angle of 6 degrees from its lowest point to both ends. Pebbles are placed on the inclined support as a support layer, and breathing ceramsite filter media is laid on top of the pebbles. The breathing ceramsite filter media has a pore size of 0.5-2mm to facilitate the exchange of water and air within the pores. The open porosity of the breathing ceramsite is 60-70%, the filling density is 50%, and the corresponding bulk density is 400-500 kg / m³. 3 The density after water absorption is 1020-1030 kg / m³. 3 After absorbing water, its density is slightly higher than that of water, allowing for backwashing with lower pressure water, resulting in low energy consumption. Furthermore, the ceramsite floats to the surface during backwashing, improving the exchange of water and air within the open pores.

[0080] S3: After being filtered through the breathing ceramic filter tank, the water enters the MCR membrane tank at a flow rate of 65T / hour. The MCR membrane tank is designed with a suction system to draw gas from the membrane module, causing the gas-water mixture in the membrane module to flow upward in the membrane tank and generate cross flow on the membrane surface. The cross flow continuously washes the membrane surface. The permeate generated by the water flow through the membrane is collected from the inside of the hollow fiber membrane to the water collection device through the suction system. It is then transported to the permeate tank through the permeate outlet at the end of the water collection device. When the MCR membrane tank is running, a pulse aeration device 16 is used for continuous aeration.

[0081] S4: The permeate is sterilized in the product water tank by adding sodium hypochlorite solution from a dosing device with a concentration of 10 kg / hour to generate product water. The sodium hypochlorite solution contains 9% sodium hypochlorite. The product water flows out from outlet 12 of the product water tank. The quality of the product water is as follows: turbidity is 0.1 NTU, COD is 1 mg / L, Escherichia coli is not detected, and total bacterial count is 5 MPN / ml.

[0082] Example 2

[0083] S1: Filter bed filtration: Air enters through inlet 3 at a speed of 650m 3The water is purged into the filter tank at a flow rate of 70T / hour. The water flows into the bottom of the filter tank from the inlet 4 at a flow rate of 70T / hour. The water flows through the first filter structure 1 of the filter tank. The first filter structure 1 is provided with a quartz sand filter media layer, a fine pebble intermediate layer with a diameter of 8-10mm, and a coarse pebble support layer with a diameter of 25-30mm from top to bottom. The bottom surface of the coarse pebble support layer has a 7-degree support plate. The water flows from the bottom inlet 4 upward to form overflow water. The overflow water enters the breathing ceramic filter media tank from the first overflow outlet 5.

[0084] S2: Filtration in the Breathing Ceramsite Filter Tank: Overflow water enters the water distributor of the breathing ceramsite filter tank. The water distributor has 3 sets of inverted conical grooves, each with several drainage holes at the bottom. The overflow water exits through these drainage holes, passes through the second filter structure 2, and then exits through the water collection port 7 at the bottom of the second filter structure 2, flowing into the MCR membrane tank. The inclined support of the second filter structure 2 has an inclination angle of 11 degrees from its lowest point to both ends. Pebbles are placed on the inclined support as a support layer, and breathing ceramsite filter media is laid on top of the pebbles. The breathing ceramsite filter media has a pore size of 0.5-2mm to facilitate the exchange of water and air within the pores. The open porosity of the breathing ceramsite is 70-75%, the filling density is 60%, and the corresponding bulk density is 500-600 kg / m³. 3 The density after water absorption is 1030-1050 kg / m³. 3 Slightly higher than water, it can be backwashed with lower pressure water, resulting in low energy consumption. Furthermore, the expanded clay particles will float to the surface during backwashing, improving the exchange of water and air in the pores.

[0085] S3: After being filtered through the breathing ceramic filter media tank, the water flows into the MCR membrane tank at an inflow rate of 70T / hour. The MCR membrane tank is designed with a suction system to draw gas from the membrane module, causing the gas-water mixture in the membrane module to flow upward in the membrane tank and generate cross flow on the membrane surface. The cross flow continuously washes the membrane surface. The permeate generated by the water flow through the membrane is collected from the inside of the hollow fiber membrane to the water collection device through the suction system. It is then transported to the permeate tank through the permeate outlet at the end of the water collection device. When the MCR membrane tank is running, a pulse aeration device 16 is used for continuous aeration.

[0086] S4: The permeate is sterilized in the product water tank by adding sodium hypochlorite solution from a dosing device with a concentration of 10 kg / hour to generate product water. The sodium hypochlorite solution contains 10% sodium hypochlorite. The product water flows out from outlet 12 of the product water tank. The quality of the product water is as follows: turbidity is 0.08 NTU, COD is 0.9 mg / L, Escherichia coli is not detected, and total bacterial count is 5 MPN / ml.

[0087] Example 3

[0088] S1: Filter bed filtration: Air enters through inlet 3 at a speed of 450m 3The water is purged into the filter tank at a flow rate of 62T / hour. The water flows into the bottom of the filter tank from the inlet 4 at a flow rate of 62T / hour. The water flows through the first filter structure 1 of the filter tank. The first filter structure 1 is provided with a quartz sand filter media layer, a fine pebble intermediate layer with a diameter of 5-7mm, and a coarse pebble support layer with a diameter of 20-25mm from top to bottom. The bottom surface of the coarse pebble support layer has a 10-degree support plate. The water flows from the bottom inlet 4 upward to form overflow water. The overflow water enters the breathing ceramic filter media tank from the first overflow outlet 5.

[0089] S2: Filtration in the Breathing Ceramsite Filter Tank: Overflow water enters the water distributor of the breathing ceramsite filter tank. The water distributor has 3 sets of inverted conical grooves, each with several drainage holes at the bottom. The overflow water exits through these drainage holes, passes through the second filter structure 2, and then exits through the water collection port 7 at the bottom of the second filter structure 2, flowing into the MCR membrane tank. The inclined support of the second filter structure 2 has an inclination angle of 15 degrees from its lowest point to both ends. Pebbles are placed on the inclined support as a support layer, and breathing ceramsite filter media is laid on top of the pebbles. The breathing ceramsite filter media has a pore size of 0.5-2mm to facilitate the exchange of water and air within the pores. The open porosity of the breathing ceramsite is 60-90%, the filling density is 50%, and the corresponding bulk density is 300-800 kg / m³. 3 The density after water absorption is 1020-1030 kg / m³. 3 After absorbing water, its density is slightly higher than that of water, allowing for backwashing with lower pressure water, resulting in low energy consumption. Furthermore, the ceramsite floats to the surface during backwashing, improving the exchange of water and air within the open pores.

[0090] S3: After being filtered through the breathing ceramic filter tank, the water enters the MCR membrane tank at a flow rate of 65T / hour. The MCR membrane tank is designed with a suction system to draw gas from the membrane module, causing the gas-water mixture in the membrane module to flow upward in the membrane tank and generate cross flow on the membrane surface. The cross flow continuously washes the membrane surface. The permeate generated by the water flow through the membrane is collected from the inside of the hollow fiber membrane to the water collection device through the suction system. It is then transported to the permeate tank through the permeate outlet at the end of the water collection device. When the MCR membrane tank is running, a pulse aeration device 16 is used for continuous aeration.

[0091] S4: The permeate is sterilized in the product water tank by adding sodium hypochlorite solution from a dosing device with a concentration of 10 kg / hour to generate product water. The sodium hypochlorite solution contains 9.5% sodium hypochlorite. The product water flows out from outlet 12 of the product water tank. The quality of the product water is as follows: turbidity is 0.1 NTU, COD is 1 mg / L, Escherichia coli is not detected, and total bacterial count is 5 MPN / ml.

[0092] The above are merely specific embodiments of this application, but the design concept of this application is not limited thereto. Any non-substantial modifications made to this application using this concept shall be considered as an infringement of the protection scope of this application.

Claims

1. A membrane-integrated water purification system, characterized in that, It includes an interconnected filtration system and a membrane system, wherein the filtration system includes a filter bed and a breathing ceramic filter media bed, and the membrane system includes an MCR membrane bed, a product water bed, and a dosing device; The filter includes a first filtration structure (1), a water inlet (4), an air inlet (3), and a first overflow outlet (5). The first filtration structure (1), the water inlet (4), and the air inlet (3) are located at the lower part of the filter, and the first overflow outlet (5) is located at the upper part of the filter. The first overflow outlet (5) is connected to the inlet of the breathing ceramsite filter media tank. The breathing ceramic filter tank includes a second filtration structure (2) and a water collection port (7). The water collection port (7) is located at the bottom of the second filtration structure (2) and is connected to the water inlet (9) of the MCR membrane tank. The permeate outlet of the MCR membrane tank is connected to the inlet of the permeate tank, and the dosing device is used to add chemicals to the permeate tank.

2. The membrane-based integrated water purification system according to claim 1, characterized in that, The membrane-integrated water purification system includes at least two layers, with the filtration system layer located on top of the membrane system layer.

3. The membrane-based integrated water purification system according to claim 1, characterized in that, The second filtration structure (2) includes breathable ceramic filter media, which satisfies at least one of the following characteristics: The filling degree of the breathable ceramic filter media in the second filter structure (2) is 35-60%; The porosity of the breathable ceramic filter media is 35-80%; The particle size range of the breathable ceramic filter media is 5–30 mm; The density of the breathable ceramic filter media after water saturation is 1020-1100 kg / m³. 3 .

4. The membrane-based integrated water purification system according to claim 1, characterized in that, The bottom of the first filter structure (1) is provided with a support plate. The height of the support plate near the breathing ceramic filter media pool is higher than the height away from the breathing ceramic filter media pool. The angle formed by the height difference is 3 to 15°.

5. The membrane-integrated water purification system according to claim 4, characterized in that, The first filter structure (1) is provided with a filter media layer, an intermediate layer and a support layer from top to bottom, and the support layer is placed on the support plate. The first filter structure (1) satisfies at least one of the following characteristics: The filter media layer includes quartz sand; The intermediate layer comprises fine pebbles; The diameter of the fine pebbles is 5-10 mm; The support layer comprises coarse pebbles; The coarse pebbles have a diameter of 20–30 mm.

6. The membrane-integrated water purification system according to claim 1, characterized in that, The bottom of the second filter structure (2) is an inclined support with high ends and low middle. The inclined support is used to support the breathing ceramic filter material. The lowest point of the inclined support is connected to the water collection port (7). The water collection port (7) is connected to the water inlet (9) of the MCR membrane tank.

7. The membrane-integrated water purification system according to claim 6, characterized in that, The water collection port (7) is connected to the water inlet (9) of the MCR membrane tank through a vertical pipe (8).

8. The membrane-based integrated water purification system according to claim 1, characterized in that, The inlet of the breathing ceramsite filter tank is provided with a water distributor (6), which is composed of at least one inverted conical groove, and the bottom of the inverted conical groove has a drain hole.

9. A membrane-based integrated water purification system according to any one of claims 1 to 8, characterized in that, The MCR membrane tank includes a suction system, a pulse aeration device (16) and at least one set of membrane modules (15). The pulse aeration device (16) is disposed below the membrane module (15). The suction system is used to suction gas and / or water from the membrane module (15).

10. The membrane-integrated water purification system according to claim 9, characterized in that, The MCR membrane pool satisfies at least one of the following characteristics: The membrane module (15) is installed in the MCR membrane tank in a detachable plug-in manner; The membrane module (15) includes hollow fiber membrane filaments, the two ends of which are the upper end and the lower end of the filtered water, respectively. At least one end of the upper end and the lower end of the filtered water is connected to a water collection device, and the water collection device is provided with the water outlet.

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