Overlapped efficient water purification method based on semi-flocculation

Abstract

The invention discloses an overlapped efficient water purification method and system based on semi-flocculation. The method comprises the following steps: adding a set amount of flocculant into a water body to be treated to form semi-flocculation flocs in the water body to be treated; introducing the water body in which the semi-flocculation flocs are formed into a filter tank provided with an air flotation facility, a surface sweeping and washing device and a filter layer; introducing bubbles into the water body in which the semi-flocculation floc is formed by adopting an air floatation facility in the filter tank, so that the semi-flocculation floc floats upwards; floating semi-flocculation flocs are removed through a surface sweeping and washing device in the filter tank; and filtering the water body in which the floating semi-flocculation flocs are removed through a filter layer in the filter tank. By utilizing the scheme of the invention, light semi-flocculation flocs can be formed, so that the light semi-flocculation flocs are brought to the surface of the filter tank through the air flotation facility, and the rest of suspended matters are removed through filtration, thereby achieving the effect of dual turbidity removal.

Description

Technical Field

[0001] The present application generally relates to the technical field of water pollutant treatment, and more specifically, to a superimposed high-efficiency water purification method based on semi-flocculation. Background Art

[0002] In the prior art, flocculation, sedimentation and filtration are usually used to remove pollutants from water. Flocculation is a key step in the process of removing pollutants from water. Flocculation refers to the process of adding flocculants to the raw water to make the suspended particles and colloidal impurities in the water collide and aggregate with each other to form larger floc particles.

[0003] However, due to the changes in the raw water quality, the addition of flocculants is not easy to control. Adding too much or too little will have adverse consequences on the formation of flocs. Usually, dense flocs are easy to precipitate, while loose ones are difficult to precipitate, which increases the pressure of the filter tank treatment and affects the effluent quality.

[0004] In view of this, there is an urgent need to provide a superimposed and efficient water purification solution based on semi-flocculation to form longer chain, more fluffy and easy-to-float flocs to effectively remove pollutants in water. Summary of the invention

[0005] In order to at least solve one or more of the technical problems mentioned above, the present application proposes a stacked high-efficiency water purification solution based on semi-flocculation in multiple aspects.

[0006] In the first aspect, the present application provides a superimposed high-efficiency water purification method based on semi-flocculation, comprising: adding a set amount of flocculant to the water body to be treated to form semi-flocculated flocs in the water body to be treated; passing the water body in which the semi-flocculated flocs are formed into a filter tank provided with an air flotation facility, a surface sweeping device and a filter layer; using the air flotation facility in the filter tank to pass bubbles into the water body in which the semi-flocculated flocs are formed to make the semi-flocculated flocs float; removing the floating semi-flocculated flocs by the surface sweeping device in the filter tank; filtering the water body from which the floating semi-flocculated flocs are removed by the filter layer in the filter tank.

[0007] In some embodiments, the set amount is the product of the optimal flocculant dosage and a set coefficient, wherein the set coefficient is greater than 1, and the optimal flocculant dosage is less than the flocculant dosage corresponding to the minimum turbidity of the water body after adding the flocculant.

[0008] In some embodiments, the difference between the optimal amount of flocculant added and the amount of flocculant added corresponding to the minimum turbidity of the water body after the flocculant is added is equal to a preset difference.

[0009] In some embodiments, the flocculant is polyaluminium chloride.

[0010] In some embodiments, a pretreatment agent is added to the water to be treated before adding a set amount of flocculant to the water to be treated.

[0011] In some embodiments, a pH adjuster is added to the water to be treated while adding a set amount of flocculant to the water to be treated.

[0012] In some embodiments, a water inlet valve, a drain valve and a backwash valve are also provided in the filter pool; in the process of removing the floating semi-flocculated flocs through the surface sweeping device in the filter pool, the water inlet valve is closed, the surface sweeping device is opened, and the drain valve is opened to discharge the floating semi-flocculated flocs.

[0013] In some embodiments, during the process of filtering the water body from which the floating semi-flocculated flocs are removed through the filter layer in the filter pool, when the filtration head loss reaches the preset filtration head value, the following steps are performed: close the drain valve, keep the surface sweeping device turned on, open the backwash air valve, and backwash the filtered water body with a water flush of a first intensity and a first duration; backwash the filtered water body with a water flush of a second intensity and a second duration, wherein the second intensity is greater than the first intensity; backwash the filtered water body with a water flush of a third intensity and a third duration, so that the water level in the filter pool is the highest water level during filtration, wherein the third intensity is greater than the second intensity; let it stand for a set time, open the drain valve, and discharge the backwash water and floating objects currently on the surface of the filter pool.

[0014] In the second aspect, the present application provides a stacked high-efficiency water purification system based on semi-flocculation, which uses the stacked high-efficiency water purification method based on semi-flocculation as described in any embodiment of the first aspect to perform high-efficiency water purification, and the system includes: a water distribution well, which is used to distribute and adjust the water volume to be treated; a reaction tank, which is used to mix and react the water output from the water distribution well with the added drugs including flocculants to form semi-flocculated flocs; a filtration tank, which is used to introduce bubbles into the water body in which the semi-flocculated flocs are formed through a flotation facility to make the semi-flocculated flocs float, and remove the floating semi-flocculated flocs through a surface sweeping device, and filter the water body from which the floating semi-flocculated flocs are removed through a filtration layer; a clear water tank, which is used to store water that has been treated by the filtration tank and disinfected.

[0015] In some embodiments, the system further includes a sedimentation tank, which is used to perform sedimentation treatment on the water output from the reaction tank when the turbidity of the water output from the reaction tank is greater than a preset turbidity value, and input the sedimentation treated water into the filtration tank.

[0016] Through the superimposed high-efficiency water purification scheme based on semi-flocculation as provided above, the embodiment of the present application passes the water body in which semi-flocculated flocs are formed into a filter pool equipped with an air flotation facility, a surface sweeping device and a filter layer, and successively passes bubbles into the filter pool to make the semi-flocculated flocs float, remove the floating semi-flocculated flocs, and filter the water body from which the floating semi-flocculated flocs are removed, so that lighter semi-flocculated flocs can be formed, so that the lighter semi-flocculated flocs are brought to the surface of the filter pool through the air flotation facility, and the remaining suspended matter is removed by filtration, achieving a double turbidity removal effect. At the same time, the bubbles injected into the filter pool can provide oxygen to the microorganisms in the filter material, and the oxygen supply to the microorganisms can better remove heavy metals, organic matter and odorous substances in the water, thereby improving the efficiency of water treatment. In addition, the reflux ratio of the flotation process can be reduced, the energy consumption of the flotation facility can be greatly reduced, and the cost involved in removing pollutants in the water can be reduced.

[0017] Furthermore, in some embodiments, during the filtering process of the water body from which the floating semi-flocculated flocs have been removed, when the filtration head loss reaches a preset filtration head value, continuously backwashing the filtered water body with different intensities and durations can restore the permeability and filtration capacity of the filter layer, and can more flexibly respond to different states of the filter layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become easy to understand. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 An exemplary flow chart of a superimposed high-efficiency water purification method based on semi-flocculation according to an embodiment of the present application is shown; Figure 2 A curve schematic diagram of obtaining the optimal dosing point according to an embodiment of the present application is shown; Figure 3 An exemplary flow chart of backwashing of a filter tank according to an embodiment of the present application is shown; Figure 4 An exemplary structural block diagram of a stacked high-efficiency water purification system based on semi-flocculation in some embodiments of the present application is shown; Figure 5 An exemplary structural block diagram of a stacked high-efficiency water purification system based on semi-flocculation according to other embodiments of the present application is shown. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0020] It should be understood that the terms "include" and "comprising" used in the specification and claims of the present application indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0021] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this application specification and claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms. It should also be further understood that the term "and / or" used in this application specification and claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0022] The specific implementation of the present application is described in detail below with reference to the accompanying drawings.

[0023] In the prior art, during the high-efficiency water purification process, after the raw water enters the water distribution well, a flocculant is added to the water distribution well, and then the water body with the flocculant is passed into the flocculation tank, where the water body and the flocculant are mixed and reacted to form large-particle coagulants. Next, the water body with large-particle coagulants is passed into the sedimentation tank, where the large-particle coagulants are removed by a sedimentation process. Then, the unprecipitated part is passed into the filtration tank, where the unprecipitated part is filtered and treated to remove the micro-polluting small molecular organic matter in the water body. Finally, the filtered water body is treated, and the disinfected water body is passed into the clear water tank.

[0024] However, due to the changes in the raw water quality, the addition of flocculants is not easy to control. Adding too much or too little will have adverse consequences on the formation of flocs. Usually, dense flocs are easy to precipitate, while loose ones are difficult to precipitate, which increases the pressure of the filter tank treatment and affects the effluent quality.

[0025] In view of this, the embodiment of the present application provides a stacked high-efficiency water purification solution based on semi-flocculation, which can form longer chain, more fluffy and easy-to-float flocs, and remove the easy-to-float flocs through flotation process, thereby effectively removing pollutants in the water.

[0026] Figure 1 An exemplary flow chart of a superimposed high-efficiency water purification method 100 based on semi-flocculation according to an embodiment of the present application is shown.

[0027] like Figure 1 As shown, in step S110, a set amount of flocculant is added to the water body to be treated to form semi-flocculated flocs in the water body to be treated.

[0028] In some embodiments of the present application, the water to be treated is first distributed and adjusted in the water distribution well, and then introduced into the reaction tank to mix and react with the added drugs including flocculants to form semi-flocculated flocs. When the turbidity of the water output from the reaction tank is greater than the preset turbidity value, the water output from the reaction tank is introduced into the sedimentation tank for sedimentation treatment, and then subsequent treatment is performed, thereby further improving the treatment effect.

[0029] In other embodiments of the present application, the water to be treated is first distributed and adjusted in the water distribution well, and then introduced into the reaction tank to mix and react with the added drugs including flocculants to form semi-flocculated flocs. When the turbidity of the water output from the reaction tank is less than or equal to the preset turbidity, subsequent treatment is performed without sedimentation treatment, thereby improving the treatment efficiency.

[0030] In the aforementioned embodiment, a stirring device may be provided in the reaction tank to stir the added medicine including flocculant and the water to be treated, so that the water to be treated and the medicine including flocculant can fully react.

[0031] In the aforementioned embodiments, a set amount of flocculant may be added to the water distribution well or the reaction tank.

[0032] In the aforementioned embodiments, the preset turbidity value may be set according to actual needs and historical experience, and the present application does not impose any limitation thereto.

[0033] In the embodiments of the present application, the aforementioned flocculant is polyaluminium chloride.

[0034] In the embodiment of the present application, the set amount is the product of the optimal dosage of the flocculant and the set coefficient.

[0035] Specifically, the aforementioned setting coefficient is greater than 1.

[0036] In the embodiments of the present application, the setting coefficient is set according to actual needs and historical experience, and the present application does not limit the specific value corresponding to it. For example, in some embodiments of the present application, the setting coefficient is set to 1.2, and the setting amount is 1.2×the optimal flocculant dosage.

[0037] Specifically, the aforementioned optimal flocculant dosage is less than the flocculant dosage corresponding to the minimum turbidity of the water body after adding the flocculant, and the difference between the optimal flocculant dosage and the flocculant dosage corresponding to the minimum turbidity of the water body after adding the flocculant is equal to the preset difference.

[0038] In the embodiments of the present application, the amount of flocculant added corresponding to when the turbidity of the water body is the smallest after the flocculant is added is the optimal dosing point, and the optimal dosing point can be determined through a beaker experiment.

[0039] In some embodiments of the present application, a curve between flocculant dosage and effluent turbidity is constructed through a beaker experiment to determine the optimal dosing point.

[0040] Figure 2 A schematic diagram of the curve of effluent turbidity-flocculant dosage in an embodiment of the present application is shown.

[0041] like Figure 2 As shown, when the flocculant dosage is 1.3 mg / L, the effluent turbidity is the smallest, that is, the optimal dosage point is 1.3 mg / L.

[0042] In the embodiments of the present application, the aforementioned preset difference can be set according to actual needs and historical experience, but at least the set amount must be greater than the corresponding amount of flocculant added when the turbidity of the water body is the minimum after the addition of the flocculant, so that an excess of flocculant is added to the water body to be treated, thereby forming semi-flocculated flocs.

[0043] Specifically, semi-flocculated flocs are an intermediate state between complete flocculation and micro-flocculation. They are fluffy multi-nuclear flocs that are easy to float and remove by adding excess flocculants. Their size is relatively small, generally between a few microns and tens of microns. Compared with the traditional flocculation process, its flocculation reaction is lighter and will not form large and dense flocs like conventional flocculation. Since semi-flocculated flocs are lighter than flocculants, they can be quickly removed by flotation.

[0044] In the embodiment of the present application, before adding a set amount of flocculant to the water body to be treated, a pretreatment agent is added to the water body to be treated. Specifically, the pretreatment agent includes permanganate, powdered activated carbon (PAC) and the like.

[0045] Specifically, the aforementioned permanganate includes lithium permanganate, sodium permanganate, potassium permanganate, ammonium permanganate, calcium permanganate, barium permanganate, zinc permanganate, magnesium permanganate and the like.

[0046] As a strong oxidant, permanganate is mainly used to remove organic pollutants, color and odor substances in water through oxidation. It can effectively destroy or change the structure of some organic matter, making it easier to be removed by subsequent treatment steps.

[0047] Powdered activated carbon (PAC) has a very large specific surface area and a well-developed pore structure, which enables it to efficiently adsorb trace organic pollutants, pesticide residues, industrial chemicals and other difficult-to-degrade organic compounds in water.

[0048] By adding pretreatment agents such as permanganate and powdered carbon to the water to be treated, permanganate can decompose large molecular organic matter into small molecules through oxidation, which are then adsorbed by powdered carbon. This not only improves the removal efficiency, but also reduces the dosage required for using any one agent alone. This combination is particularly suitable for treating water bodies with complex components or affected by multiple types of pollution sources, which can reduce the workload of subsequent treatment stages and ultimately achieve higher purification standards.

[0049] In the embodiment of the present application, a pH regulator is added to the water body to be treated while adding a set amount of flocculant to the water body to be treated. Specifically, the pH regulator includes lime, carbon dioxide, and the like.

[0050] In the embodiments of the present application, the amount and type of pH regulator added can be controlled according to the types of pollutants in the water body to be treated, so that the pH of the water body to be treated satisfies the formation of the largest number of semi-flocculated flocs and / or the fastest speed of forming semi-flocculated flocs, thereby effectively removing turbidity, algae, and some volatile small molecular organic matter, thereby improving the treatment efficiency of pollutants in the water.

[0051] After executing step S110, in step S120, the water body in which the semi-flocculated flocs are formed is introduced into a filter tank provided with an air flotation facility, a surface sweeping device and a filter layer.

[0052] In an embodiment of the present application, an inlet valve, a drain valve, a backwash air valve, an outlet valve, etc. are also provided in the filter tank. The inlet valve is used for the entry of water in which semi-flocculated flocs are formed, the drain valve is used for the discharge of scum including semi-flocculated flocs and backwash water, the backwash air valve is used for the entry of backwash water, and the outlet valve is used for outputting the obtained water to the clean water tank after all the work in the filter tank is completed.

[0053] In an embodiment of the present application, the flotation facility includes an air compressor, an air dissolving tank and an air release device. The air dissolving tank is connected to the air compressor and connected to the clean water tank through a reflux pump and a valve. The air release device is connected to the air dissolving tank. The air compressor inputs compressed air into the air dissolving tank. When the pressure in the air dissolving tank reaches a preset value, the reflux pump is started, and the valve is slowly opened to input clean water into the air dissolving tank to dissolve the compressed air. Then, the water dissolved with air passes through the air release device, and the pressure is instantly reduced to release a large number of fine bubbles.

[0054] In an embodiment of the present application, the filter tank is further provided with two surface sweeping holes, which are respectively arranged on two opposite side walls of the filter tank and have the same height. The surface sweeping device is arranged at the water inlet position of the filter tank, which may include a V-shaped plate and a water sweeping guide structure. The V-shaped plate is fixed on the side wall of the filter tank, and the water sweeping guide structure is located on the V-shaped plate. The water sweeping guide structure includes a guide plate and a drainage tube. The plate surface of the guide plate is at the same height as the liquid level in the filter tank and is located in the same plane. The cross-section of the drainage tube is trapezoidal, with the small radius end facing the liquid level in the filter tank, and the water inlet of the drainage tube is directly opposite to the position of the two surface sweeping holes on the filter tank. A fan-shaped water outlet area is provided on the guide plate, which is located between the two surface sweeping holes. The size of the surface sweeping hole is larger than the area occupied by the two drainage tubes, so that the water flow area rushing toward the liquid surface in the filter tank can be expanded while accelerating. The guide plate is provided with guide grooves, which are distributed in a fan shape from the surface sweeping holes toward the drainage tube, which can guide the water flow to form a fan-shaped outflow, and make part of the water flow converge and flow to the water inlet on the drainage tube, and finally flow into the filter pool.

[0055] Through the above structure, when the water to be filtered passes through the surface sweeping holes of the filter tank, the sweeping water guide structure will accelerate the water flowing out of the surface sweeping holes and make it form a fan-shaped water flow to the liquid surface position in the filter tank. This design can change the direction and shape of the water flow, so that the sweeping water can enter the liquid surface angle of the filter tank more effectively, thereby fully sweeping the scum on the liquid surface to the drainage tank.

[0056] In an embodiment of the present application, the filter layer includes a carbon layer.

[0057] Specifically, the thickness of the carbon layer is 1.5m-2.0m.

[0058] Specifically, the carbon layer uses activated carbon, and the activated carbon is selected as crushed briquette carbon (or raw coal crushed carbon), the activated carbon strength is greater than 95%, and the carbon layer selects customized filter material, and the particle size of the customized filter material is 16×30 mesh. By selecting the grading of the customized filter material and the activated carbon strength of more than 95%, it can be similar to the filter material particle size of the sand filter pool, which can improve the turbidity removal efficiency, increase the service life of the activated carbon, and effectively remove odors and organic matter. In addition, the semi-flocculated flocs in the water body are removed by the aforementioned flotation facilities. When filtering, the surface load of the filter pool can be reduced and the service life of the activated carbon can be increased.

[0059] In the embodiment of the present application, the flotation facility and the filter layer are combined in the same tank body, and air bubbles are injected into the filter tank through the flotation facility, so that the semi-flocculated flocs in the water body adhere to the air bubbles and float to the water surface with the air bubbles, and the remaining suspended matter is processed by filtration to achieve a double turbidity removal effect. At the same time, the air bubbles injected into the filter tank can provide oxygen to the microorganisms in the filter material, and the microbial nutrition can better remove heavy metals such as iron and manganese, organic matter and odor substances in the water, thereby improving the efficiency of water treatment.

[0060] In an embodiment of the present application, a surface sweeping device is provided at the water inlet of the filter tank, so that scum including semi-flocculated flocs are removed together when the filter tank is backwashed, and the backwash water of the filter tank directly enters the drain tank. Compared with the prior art that requires special scum removal equipment for scum treatment in the flotation tank, the embodiment of the present application can reduce equipment and save energy consumption of the flotation process.

[0061] After step S120 is performed, in step S130, air bubbles are introduced into the water body in which the semi-flocculated flocs are formed by using the air flotation facility in the filtration tank, so that the semi-flocculated flocs float.

[0062] In the embodiments of the present application, by adding an excessive amount of flocculation flocs, the collision chance of particles is increased, and a semi-flocculation floc with multiple coagulation cores is formed. The adsorption and bridging capacity of the semi-flocculation floc is increased, and the overgrowth has the characteristics of longer chains, more fluffy, easier to float and easy to break, and it is easy to float to the upper layer. After air bubbles are introduced into the water body in which the semi-flocculation floc is formed using the flotation facility in the filtration tank, the semi-flocculation floc adheres to the air bubbles and easily floats to the water surface with the air bubbles. Therefore, a shallower effective water depth and a smaller reflux ratio can be used in the flotation process.

[0063] Compared with the flotation process in the prior art which requires a water depth of 2m-7m, in the embodiment of the present application, it is only necessary to set the effective water depth corresponding to the flotation facility in the flotation process to be greater than or equal to 1m and less than 2m, thereby effectively reducing the construction cost.

[0064] Compared with the prior art, the flotation process requires a 5%-10% reflux ratio to ensure that there are enough bubbles in the water to react with the pollutants in the water and ensure a good removal effect. In the embodiment of the present application, the reflux ratio of the flotation facility only needs to be set to 1%-5%, thereby greatly reducing the energy consumption of the flotation facility.

[0065] After step S130 is performed, in step S140, the floating semi-flocculated flocs are removed by a surface sweeping device in the filter tank.

[0066] In the embodiment of the present application, in the process of removing the floating semi-flocculated flocs by the surface sweeping device in the filter tank, the water inlet valve is closed, the surface sweeping device is opened, and the drain valve is opened to discharge the floating semi-flocculated flocs.

[0067] After step S140 is performed, in step S150, the water body from which the floating semi-flocculated flocs are removed is filtered through a filter layer in the filter pool.

[0068] In the embodiment of the present application, during the filtering process of the water body from which the floating semi-flocculated flocs are removed, the filtering rate can be 10m / h-15m / h, and the filtering period can be 24h-48h. Compared with the normal filtering rate of the filtering pool in the prior art, which is preferably 8-10m / h, the forced filtering rate is preferably 10-13m / h. Since the present application integrates the flotation facility and the filtering layer in the same pool body, and filtering is performed after the floating semi-flocculated flocs are removed, the filtering pressure is small, thereby accelerating the filtering rate, thereby improving the removal efficiency of pollutants in the water.

[0069] In an embodiment of the present application, in the process of filtering the water body from which the floating semi-flocculated flocs are removed through the filter layer in the filter pool, when the filtration head loss reaches the filtration head preset value, the filter pool is backwashed, and when the filtration head loss does not reach the filtration head preset value, the filtration treatment steps are continued.

[0070] Filtration head loss refers to the energy loss when water flows through the filter medium and the filter equipment pipeline. During the filtration process, as the filtration time increases, the pollutants trapped in the filter medium increase, which increases the pressure energy or potential energy loss of the water that promotes the filtration process, that is, the filtration head loss increases. When it reaches a certain value, the filter tank should be backwashed, otherwise the head loss will increase sharply, even causing negative pressure, or the water quality will deteriorate sharply. Therefore, when the filtration head loss reaches the preset value of the filtration head, the filter tank should be backwashed.

[0071] In the embodiments of the present application, the preset value of the filtration head is set according to actual needs and historical experience, and the present application does not limit this.

[0072] In the embodiments of the present application, the specific process of backwashing the filter tank can be found in Figure 3 .

[0073] Figure 3 An exemplary flow chart of backwashing of a filter tank according to an embodiment of the present application is shown.

[0074] like Figure 3 As shown, in step S310, the drain valve is closed, the surface sweeping device is kept turned on, the backwashing valve is opened, and the filter pool is backwashed with water of a first intensity and a first duration. In step S320, the filter pool is backwashed with water of a second intensity and a second duration, wherein the second intensity is greater than the first intensity. In step S330, the filter pool is backwashed with water of a third intensity and a third duration, so that the water level in the filter pool is the highest water level during filtration, wherein the third intensity is greater than the second intensity. In step S340, the filter pool is left to stand for a set time, and the drain valve is opened to discharge the backwashing water and the floating objects on the current filter pool surface.

[0075] Specifically, the backwash water and the floating objects currently on the surface of the filter tank are discharged into the drainage tank.

[0076] In the embodiments of the present application, the first intensity, the first duration, the second intensity, the second duration, the third intensity and the third duration can be set according to actual needs and historical experience. The present application does not limit the scope involved here, but it is necessary to ensure that the second intensity is greater than the first intensity, the third intensity is greater than the second intensity, the second duration is greater than the first duration, and the third duration is less than the first duration, and it is necessary to ensure that after the filter pool is backwashed with water of the third intensity and the third duration, the water level in the filter pool is the highest water level during filtration.

[0077] In some embodiments of the present application, the first intensity is 15L / (sm 2 ), the first duration is 3min, the second intensity is 2L / (sm 2 )-3L / (sm 2 ), the second duration is 4min-5min, and the third intensity is 15 (sm 2 )-16(sm 2 ), the third duration is 1min.

[0078] In the embodiment of the present application, during the backwashing process of the filter pool, by setting the first intensity, the first duration, the second intensity, the second duration, the third intensity and the third duration, a lower intensity but longer duration is used in the initial stage of backwashing to help loosen the mild blockage; then gradually increasing the intensity and completing high-intensity flushing in a short time is conducive to removing more stubborn sediments. Thus, the sludge on the surface of the filter material can be removed, and the rearrangement of the internal structure of the filter layer can be promoted, so that the porosity is increased, thereby reducing the head loss and improving the filtration efficiency.

[0079] In an embodiment of the present application, after the water body from which the floating semi-flocculated flocs have been removed has been filtered, a disinfectant is added to the filtered water body, and after the water body has been disinfected by the disinfectant, the obtained water body is passed into a clean water tank.

[0080] In summary, through the superimposed high-efficiency water purification scheme based on semi-flocculation as provided above, the embodiment of the present application passes the water body in which semi-flocculated flocs are formed into a filter pool equipped with a flotation facility, a surface sweeping device and a filter layer, and successively passes bubbles into the filter pool to make the semi-flocculated flocs float, remove the floating semi-flocculated flocs, and filter the water body from which the floating semi-flocculated flocs are removed, so that lighter semi-flocculated flocs can be formed, so that the lighter semi-flocculated flocs are brought to the surface of the filter pool through the flotation facility, and the remaining suspended matter is removed by filtration, achieving a double turbidity removal effect. At the same time, the bubbles injected into the filter pool can provide oxygen to the microorganisms in the filter material, and the oxygen supply to the microorganisms can better remove heavy metals, organic matter and odorous substances in the water, thereby improving the efficiency of water treatment. In addition, the reflux ratio of the flotation process can be reduced, the energy consumption of the flotation facility can be greatly reduced, and the cost involved in removing pollutants in the water can be reduced.

[0081] Furthermore, in some embodiments, during the filtering process of the water body from which the floating semi-flocculated flocs have been removed, when the filtration head loss reaches a preset filtration head value, continuously backwashing the filtered water body with different intensities and durations can restore the permeability and filtration capacity of the filter layer, and can more flexibly respond to different states of the filter layer.

[0082] The embodiment of the present application also provides a stacked high-efficiency water purification system based on semi-flocculation, which can use the aforementioned stacked high-efficiency water purification method 100 based on semi-flocculation for high-efficiency water purification, or can use other methods for high-efficiency water purification, which is not limited in the present application.

[0083] Figure 4 An exemplary structural block diagram of a stacked high-efficiency water purification system 400 based on semi-flocculation according to some embodiments of the present application is shown.

[0084] like Figure 4 As shown, the system 400 includes a water distribution well 410 , a reaction tank 420 , a filtration tank 430 and a clean water tank 440 .

[0085] Specifically, the water distribution well 410 is used to distribute and regulate the amount of water to be treated.

[0086] Specifically, the reaction tank 420 is used to mix and react the water output from the water distribution well with the added medicine including flocculants to form semi-flocculated flocs.

[0087] Specifically, a set amount of flocculant is added to the water distribution well 410 or the reaction tank 420 .

[0088] Specifically, the filter tank 430 is used to introduce bubbles into the water body in which semi-flocculated flocs are formed through the flotation facility to make the semi-flocculated flocs float, and remove the floating semi-flocculated flocs through the surface sweeping device, and filter the water body from which the floating semi-flocculated flocs are removed through the filter layer.

[0089] Specifically, the clean water tank 440 is used to store the water that has been processed and disinfected by the filter tank 430.

[0090] When the system 400 uses the aforementioned semi-flocculation-based superimposed efficient water purification method 100 for efficient water purification, the aforementioned step S110 is performed in the reaction tank 420, or the aforementioned step S110 is performed in the water distribution well 410 and the reaction tank 420, and the aforementioned steps S120 to S150 are performed in the filter tank 430. The specific execution process can be referred to above, and will not be repeated here.

[0091] Figure 5 An exemplary structural block diagram of a stacked high-efficiency water purification system 500 based on semi-flocculation according to some other embodiments of the present application is shown.

[0092] like Figure 5 As shown, the system 500 includes a water distribution well 510 , a reaction tank 520 , a sedimentation tank 530 , a filtration tank 540 and a clean water tank 550 .

[0093] Specifically, the water distribution well 510 is used to distribute and regulate the amount of water to be treated.

[0094] Specifically, the reaction tank 520 is used to mix and react the water output from the water distribution well with the added medicine including flocculants to form semi-flocculated flocs.

[0095] Specifically, a set amount of flocculant is added to the water distribution well 510 or the reaction tank 520 .

[0096] Specifically, the sedimentation tank 530 is used to perform sedimentation treatment on the water output from the reaction tank 520 when the turbidity of the water output from the reaction tank 520 is greater than a preset turbidity value, and input the sedimentation treated water into the filter tank 540 .

[0097] Specifically, the filter tank 540 is used to introduce bubbles into the water body in which semi-flocculated flocs are formed output from the sedimentation tank 530 through an air flotation facility to make the semi-flocculated flocs float, and remove the floating semi-flocculated flocs through a surface sweeping device, and filter the water body from which the floating semi-flocculated flocs are removed through a filter layer.

[0098] The clean water tank is used to store water that has been treated in the filter tank and disinfected.

[0099] When the system 500 uses the aforementioned superimposed high-efficiency water purification method 100 based on semi-flocculation for high-efficiency water purification, the aforementioned step S110 is performed in the reaction tank 520, or the aforementioned step S110 is performed in the aforementioned water distribution well 510 and the reaction tank 520, the aforementioned steps S120 to S150 are performed in the filter tank 540, and the relevant steps of the sedimentation treatment are performed in the sedimentation tank 530. The specific execution process can be referred to the above, and will not be repeated here.

[0100] Although multiple embodiments of the present application have been shown and described herein, it is obvious to those skilled in the art that such embodiments are provided only by way of example. Those skilled in the art can think of many changes, modifications and alternatives without departing from the thought and spirit of the present application. It should be understood that in the process of practicing the present application, various alternatives to the embodiments of the present application described herein can be adopted. The attached claims are intended to limit the scope of protection of the present application, and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A superimposed high-efficiency water purification method based on semi-flocculation, characterized in that: include: adding a set amount of flocculant to the water to be treated to form semi-flocculated flocs in the water to be treated; The water body in which the semi-flocculated flocs are formed is passed into a filter tank provided with an air flotation facility, a surface sweeping and washing device and a filter layer; Using an air flotation facility in a filter tank to introduce air bubbles into a water body in which semi-flocculated flocs are formed, so that the semi-flocculated flocs float; The floating semi-flocculated flocs are removed by a surface sweeping device in the filter tank; The water body from which the floating semi-flocculated flocs are removed is filtered through a filter layer in a filter tank.

2. The superimposed high-efficiency water purification method based on semi-flocculation according to claim 1, characterized in that: The set amount is the product of the optimal amount of flocculant added and a set coefficient, wherein the set coefficient is greater than 1, and the optimal amount of flocculant added is less than the amount of flocculant added corresponding to the minimum turbidity of the water body after the flocculant is added.

3. The superimposed high-efficiency water purification method based on semi-flocculation according to claim 2, characterized in that: The difference between the optimal amount of flocculant added and the amount of flocculant added corresponding to the minimum turbidity of the water body after the flocculant is added is equal to the preset difference.

4. The superimposed high-efficiency water purification method based on semi-flocculation according to claim 1, characterized in that: The flocculant is polyaluminium chloride.

5. The superimposed high-efficiency water purification method based on semi-flocculation according to claim 1, characterized in that: Before adding a set amount of flocculant to the water body to be treated, a pretreatment agent is added to the water body to be treated.

6. The superimposed high-efficiency water purification method based on semi-flocculation according to claim 5, characterized in that: While adding a set amount of flocculant to the water body to be treated, a pH regulator is added to the water body to be treated.

7. The superimposed high-efficiency water purification method based on semi-flocculation according to claim 1, characterized in that: The filter tank is also provided with a water inlet valve, a drain valve and a recoil valve; In the process of removing the floating semi-flocculated flocs by the surface sweeping and washing device in the filter tank, the water inlet valve is closed, the surface sweeping and washing device is opened, and the drain valve is opened to discharge the floating semi-flocculated flocs.

8. The superimposed high-efficiency water purification method based on semi-flocculation according to claim 7, characterized in that: In the process of filtering the water body from which the floating semi-flocculated flocs are removed through the filter layer in the filter tank, when the filter head loss reaches the filter head preset value, the following steps are performed: closing the drain valve, keeping the surface sweeping device turned on, opening the backwashing air valve, and backwashing the filtered water body with a water flushing of a first intensity and a first duration; Backwashing the filtered water body with a water flushing of a second intensity and a second duration, wherein the second intensity is greater than the first intensity; Backwashing the filtered water body with a third intensity and a third duration so that the water level in the filter pool is the highest water level during filtration, wherein the third intensity is greater than the second intensity; After standing for a set time, the drain valve is opened to discharge the backwash water and floating objects currently on the surface of the filter tank.

9. A superimposed high-efficiency water purification system based on semi-flocculation, characterized in that: The method for high-efficiency water purification based on semi-flocculation is used to purify water efficiently, and the system comprises: Water distribution wells, used to distribute and regulate the amount of water to be treated; A reaction tank, used for mixing and reacting the water outputted from the water distribution well with the added medicine including flocculant to form semi-flocculated flocs; A filtration tank, for introducing air bubbles into a water body in which semi-flocculated flocs are formed through an air flotation device to make the semi-flocculated flocs float, removing the floating semi-flocculated flocs through a surface sweeping device, and filtering the water body from which the floating semi-flocculated flocs are removed through a filtration layer; The clean water tank is used to store water that has been treated in the filter tank and disinfected.

10. The semi-flocculation-based superimposed high-efficiency water purification system according to claim 9, characterized in that: The system further comprises a sedimentation tank, which is used to perform sedimentation treatment on the water output from the reaction tank when the turbidity of the water output from the reaction tank is greater than a preset turbidity value, and input the sedimentation treated water into the filtration tank.

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