Graded coagulation water purification treatment system

Abstract

The utility model discloses a graded coagulation water purification treatment system which comprises a raw water inlet and a dosing device, and further comprises a primary mixing area, a primary flocculation area, a secondary mixing area and a secondary flocculation area which are communicated in sequence, the dosing device is respectively connected with the first-stage mixing area and the second-stage mixing area, the first-stage mixing area and the second-stage mixing area are internally provided with stirring machines, and the first-stage flocculation area and the second-stage flocculation area are internally provided with flocculation reactors. In the graded coagulation water purification treatment system provided by the utility model, the chemical dosing device respectively feeds chemicals into the primary mixing area and the secondary mixing area, water enters from the raw water inlet, realizes primary mixing with the chemicals in the primary mixing area, then realizes primary flocculation in the primary flocculation area, and then enters the secondary mixing area; the coagulant and chemicals are secondarily mixed in the secondary mixing area, and then secondary flocculation is realized in the secondary flocculation area, so that the effluent turbidity is reduced, the coagulation effect is good, the dosage of the coagulant is reduced, and the content of residual aluminum in the effluent is reduced.

Description

Technical Field

[0001] The utility model relates to the field of water treatment, in particular to a graded coagulation water purification system. Background Art

[0002] Coagulation refers to the process of destabilizing and agglomerating small suspended particles and colloids in water by adding chemical agents such as coagulants. In the conventional water treatment process of water treatment plants, coagulation is a conventional process at the front end, and the quality of coagulation directly affects the normal operation of subsequent sedimentation and filtration processes. At present, the coagulation process of conventional treatment in water treatment plants mainly adopts the process form of "front-end dosing and mixing, back-end flocculation tank flocculation" of one-time dosing and one-time flocculation. One-time dosing and mixing refers to the addition of flocculants such as PAC to the raw water before it enters the flocculation tank, and one-time flocculation refers to the process of forming flocs in the flocculation tank by gentle turning and stirring of water flow. The front-end mixing methods include mixing tank mixing, mechanical stirring mixing, water pump mixing and tubular mixing, and the back-end flocculation tank process methods include folded plates, grids, bars, etc.

[0003] If the dosage of coagulant is too low during the coagulation process, the coagulation between the coagulant and the colloidal particles cannot effectively polymerize the coagulant and the colloidal particles in the water to produce floccules of sufficient specific gravity, and the removal effect cannot meet the requirements. If the dosage of coagulant is increased, a sufficient amount of coagulant can compress the hydration shell of organic matter, and the cations produced by the hydrolysis of the coagulant are electrically neutralized with the organic molecules with anions, eliminating the hindering effect of organic matter on the aggregation of inorganic colloidal particles. However, excessive addition of coagulant is not conducive to the coagulation effect and will lead to the phenomenon of "colloid protection", that is, too much coagulant polymer completely covers the surface of the colloidal particles in the water, and the new particles formed repel each other, which has a negative effect on the formation of floccules. Moreover, the high dosage of coagulant also brings the problem of increased operating costs and reduced economic efficiency. Especially for low-temperature and low-turbidity water with a water temperature below 10°C and a turbidity below 30NTU, the colloidal particles are evenly dispersed and highly stable, and the hydrolysis of the coagulant is difficult, which brings certain difficulties to the water purification process. Water plants generally increase the amount of coagulants added, but this method not only fails to achieve good treatment results, but also increases treatment costs and water production costs. When PAC and other coagulants are added in excess, the residual aluminum ions in the water will cause certain health risks to the human nervous, digestive and immune systems. In severe cases, it will cause symptoms such as memory loss, intestinal obstruction, decreased immunity and osteoporosis.

[0004] A Chinese invention patent application (publication number CN108083399A) discloses a method of graded enhanced coagulation. Through the graded enhanced coagulation method based on polyaluminium chloride and zirconium tetrachloride, the residual aluminium content in the effluent can be reduced and the sedimentation performance is good, but the corresponding graded coagulation structure is not disclosed. Utility Model Content

[0005] In order to solve the problems of high effluent turbidity and high aluminum content caused by one-time addition of coagulant in conventional coagulation, the utility model provides a graded coagulation water purification system.

[0006] The utility model is realized through the following technical solutions.

[0007] A graded coagulation water purification system comprises a raw water inlet and a dosing device, and also comprises a primary mixing zone, a primary flocculation zone, a secondary mixing zone and a secondary flocculation zone. The raw water inlet, the primary mixing zone, the primary flocculation zone, the secondary mixing zone and the secondary flocculation zone are connected in sequence. The dosing device is connected to the primary mixing zone and the secondary mixing zone respectively. Agitators are arranged in the primary mixing zone and the secondary mixing zone. Flocculation reactors are arranged in the primary flocculation zone and the secondary flocculation zone.

[0008] Furthermore, the primary mixing zone and the secondary mixing zone are in the form of pipeline mixers or tank bodies.

[0009] Furthermore, the primary flocculation zone and the secondary flocculation zone are in the form of pipes or tanks.

[0010] Furthermore, the mixer is a mechanical mixer.

[0011] Furthermore, a turbidity detector and a flow meter are arranged on the pipeline between the raw water inlet and the primary mixing zone.

[0012] Furthermore, the dosing device comprises two sets, one set is connected to the primary mixing zone, and the other set is connected to the secondary mixing zone.

[0013] Furthermore, the drug administration device comprises a drug storage room, a drug dosing metering pump and a drug dosing flow meter, and the drug storage room, the drug dosing metering pump, the drug dosing flow meter, the primary mixing zone or the secondary mixing zone are connected in sequence.

[0014] The beneficial effects of the utility model are:

[0015] 1. In the graded coagulation water purification system provided by the utility model, during the graded coagulation process, the first-stage flocculation can ensure that the colloidal particles can undergo sufficient electrical neutralization and destabilization, and mainly micro-flocs are formed. The second-stage flocculation can enable the micro-flocs to form large flocs through adsorption bridging and net capture and sweeping, thereby reducing the turbidity of the effluent, achieving good coagulation effect, reducing the amount of coagulant added, and reducing the residual aluminum content in the effluent.

[0016] 2. The graded coagulation water purification system provided by the utility model more effectively separates the coagulation process, relatively clearly separates the mixed coagulation process from the flocculation process, and is more conducive to the efficient implementation and process control of the coagulation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a process flow chart of the utility model;

[0018] Figure 2-8 They are system diagrams showing the connection of different forms of the primary mixing zone, the primary flocculation zone, the secondary mixing zone and the secondary flocculation zone of the utility model.

[0019] In the figure: raw water inlet 1, turbidity detector 2, flow meter 3, primary mixing zone 4, primary flocculation zone 5, secondary mixing zone 6, secondary flocculation zone 7, mixer 8, flocculation reactor 9, drug storage rooms 111, 121, drug dosing metering pumps 112, 122, and drug dosing flow meters 113, 123. DETAILED DESCRIPTION

[0020] The following is a further description of the structures involved in the present invention or the technical terms used. These descriptions are merely examples of how the present invention is implemented and do not constitute any limitation to the present invention.

[0021] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left" and "right" indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the positions or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, unless otherwise clearly specified and limited, "connection", "fixation" and the like should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1-8 As shown, a graded coagulation water purification system includes a raw water inlet 1 and a dosing device, and also includes a primary mixing zone 4, a primary flocculation zone 5, a secondary mixing zone 6 and a secondary flocculation zone 7. The raw water inlet 1, the primary mixing zone 4, the primary flocculation zone 5, the secondary mixing zone 6 and the secondary flocculation zone 7 are connected in sequence, the dosing device is connected to the primary mixing zone 4 and the secondary mixing zone 6 respectively, a stirrer 8 is arranged in the primary mixing zone 4 and the secondary mixing zone 6, and a flocculation reactor 9 is arranged in the primary flocculation zone and the secondary flocculation zone.

[0024] The dosing device adds chemicals to the primary mixing zone 4 and the secondary mixing zone 6 respectively. Water enters from the raw water inlet 1 and achieves primary mixing with the chemicals in the primary mixing zone 4, and then achieves primary flocculation in the primary flocculation zone 5. Then the water enters the secondary mixing zone 6, and achieves secondary mixing with the chemicals in the secondary mixing zone 6, and then achieves secondary flocculation in the secondary flocculation zone 7.

[0025] The first-level flocculation can ensure that the colloidal particles can undergo sufficient electrical neutralization and destabilization, and mainly form micro-flocs. The second-level flocculation can enable the micro-flocs to form large flocs through adsorption bridging and net capture and sweeping. The turbidity of the effluent is reduced, the coagulation effect is good, the amount of mixed agent added is reduced, and the residual aluminum content in the effluent is reduced.

[0026] The utility model separates the coagulation process more effectively, performs relatively clear separation of the mixed coagulation process and the flocculation process, and is more conducive to the efficient conduct and process control of the coagulation process.

[0027] The forms of the primary mixing zone 4 and the secondary mixing zone 6 include but are not limited to: various forms of pipeline mixers, tanks, etc. The pipeline mixer has a stirrer that can stir the water body to achieve mixing of the medicine and the water body, which belongs to the prior art.

[0028] The forms of the primary flocculation zone 5 and the secondary flocculation zone 7 include but are not limited to: various forms of pipes, tanks, etc. The flocculation reactor aggregates and enlarges the suspended particles in the water to form flocs, thereby accelerating the coagulation of particles and achieving the purpose of solid-liquid separation, and is an existing device.

[0029] Specifically, the primary mixing zone 4 adopts a pipeline mixer, the primary flocculation zone 5 adopts a pipeline, the secondary mixing zone 6 adopts a tank body, the secondary flocculation zone 7 adopts a tank body, and the secondary mixing zone 6 and the secondary flocculation zone 7 share a tank body, see Figure 2 .

[0030] Alternatively, the primary mixing zone 4 and the secondary mixing zone 6 both use a tank body, the primary flocculation zone 5 uses a pipeline, and the secondary mixing zone 6 and the secondary flocculation zone 7 share a tank body, see Figure 3 .

[0031] Alternatively, both the primary mixing zone 4 and the secondary mixing zone 6 use pipeline mixers, the primary flocculation zone 5 uses pipelines, and the secondary flocculation zone 7 uses a tank body, see Figure 4 .

[0032] Alternatively, the primary mixing zone 4 adopts a tank, the primary flocculation zone 5 adopts a pipeline, the secondary mixing zone 6 adopts a pipeline mixer, and the secondary flocculation zone 7 adopts a tank, see Figure 5 .

[0033] Alternatively, the primary mixing zone 4 adopts a pipeline mixer, the primary flocculation zone 5 adopts a tank body, the secondary mixing zone 6 and the secondary flocculation zone 7 both adopt a tank body, and the primary flocculation zone 5, the secondary mixing zone 6 and the secondary flocculation zone 7 share a tank body, see Figure 6 .

[0034] Alternatively, the primary mixing zone 4, the primary flocculation zone 5, the secondary mixing zone 6 and the secondary flocculation zone 7 all use a tank body, and the primary mixing zone 4, the primary flocculation zone 5, the secondary mixing zone 6 and the secondary flocculation zone 7 share a tank body, see Figure 7 .

[0035] Alternatively, the primary mixing zone 4 uses a tank body, the primary flocculation zone 5 uses a tank body, the secondary mixing zone 6 uses a pipeline mixer, the secondary flocculation zone 7 uses a tank body, and the primary mixing zone 4 and the primary flocculation zone 5 share a tank body, see Figure 8 .

[0036] Among them, the drugs for primary administration include but are not limited to different types of coagulants, such as PAC, etc., and the drugs for secondary administration include but are not limited to different types of coagulants and coagulants.

[0037] As an optional embodiment, a turbidity detector 2 and a flow meter 3 are arranged on the pipeline between the raw water inlet 1 and the primary mixing zone 4 to monitor the turbidity and flow of the water body.

[0038] As an optional embodiment, the dosing device includes two sets, one set is connected to the primary mixing zone 4, and the other set is connected to the secondary mixing zone 5. The separate dosing is beneficial to control the dosing time and dosage.

[0039] As an optional embodiment, the dosing device includes a drug storage room, a drug dosing metering pump and a drug dosing flow meter. Specifically, the drug storage room 111, the drug dosing metering pump 112, the drug dosing flow meter 113, and the primary mixing area 4 are connected in sequence, and the drug storage room 121, the drug dosing metering pump 122, the drug dosing flow meter 123, and the secondary mixing area 6 are connected in sequence.

[0040] The installation distance between the pipe and the tank is determined by the inlet flow rate and the interval between the two-stage dosing. The effluent from the secondary flocculation zone continues to flow into the sedimentation tank, filter tank and other conventional treatment process sections of the water treatment plant for further treatment.

[0041] A small-scale experiment of graded coagulation was conducted using the source water of a water plant. The turbidity of the raw water was between 4.02NTU and 8.02NTU, and PAC was used as the coagulant. The turbidity of the effluent from conventional coagulation was 0.310NTU, while the turbidities of the effluents from graded coagulation with three dosing ratios of 1:9, 2:8 and 3:7 were 0.086NTU, 0.023NTU and 0.120NTU respectively. When the same dosage of coagulant was used, the turbidities of the effluents from graded coagulation with three dosing ratios of 1:9, 2:8 and 3:7 were all lower than those from conventional coagulation, and the lowest turbidity of the effluent from graded coagulation was only 7.4% of that from conventional coagulation.

[0042] The production verification of graded coagulation was carried out in a water plant in Zhengzhou City, Henan Province. The turbidity of the raw water was 2.61NTU~5.15NTU, and PAC was used as the coagulant. The turbidity of the conventional coagulation effluent was 0.175NTU, and the turbidity of the effluents of the three dosing ratios of graded coagulation 6:4, 7:3, and 8:2 were 0.156NTU, 0.153NTU, and 0.154NTU, respectively. The lowest effluent turbidity of graded coagulation was 87.4% of that of conventional coagulation.

[0043] It can be seen that when the same dosage of coagulant is used, the effluent turbidity of the graded coagulation using this system is lower than that of the conventional coagulation.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A graded coagulation water treatment system, comprising a raw water inlet and a dosing device, characterized in that: It also includes a primary mixing zone, a primary flocculation zone, a secondary mixing zone and a secondary flocculation zone. The raw water inlet, the primary mixing zone, the primary flocculation zone, the secondary mixing zone and the secondary flocculation zone are connected in sequence. The dosing device is connected to the primary mixing zone and the secondary mixing zone respectively. Agitators are arranged in the primary mixing zone and the secondary mixing zone. Flocculation reactors are arranged in the primary flocculation zone and the secondary flocculation zone.

2. A graded coagulation water purification system according to claim 1, characterized in that: The primary mixing zone and the secondary mixing zone are in the form of pipeline mixers or tank bodies.

3. A graded coagulation water purification system according to claim 1, characterized in that: The primary flocculation zone and the secondary flocculation zone are in the form of pipelines or tanks.

4. A graded coagulation water purification system according to claim 1, characterized in that: The mixer is a mechanical mixer.

5. A graded coagulation water purification system according to claim 1, characterized in that: A turbidity detector and a flow meter are arranged on the pipeline between the raw water inlet and the primary mixing zone.

6. A graded coagulation water purification system according to claim 1, characterized in that: The dosing device comprises two sets, one set is connected to the primary mixing zone, and the other set is connected to the secondary mixing zone.

7. A graded coagulation water purification system according to claim 6, characterized in that: The drug dosing device comprises a drug storage room, a drug dosing metering pump and a drug dosing flow meter, and the drug storage room, the drug dosing metering pump, the drug dosing flow meter, and a primary mixing area or a secondary mixing area are connected in sequence.

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