Artificial rapid infiltration water purification device

Abstract

The invention discloses an artificial rapid infiltration water purification device, which belongs to the technical field of sewage treatment and comprises an infiltration tank body. The upper part of the infiltration tank body is provided with a water distribution area, a gravel area, an aerobic zone one, an aerobic zone two and an aerobic zone three in sequence from top to bottom. The lower part of the infiltration tank body comprises an anoxic zone one, anoxic zone two and ceramsite zone one. The top of the anoxic zone one is connected with the bottom of the aerobic zone three. The anoxic zone one is connected with the anoxic zone two through the ceramsite zone one located at the bottom. A drainage outlet is arranged on one side of the anoxic zone two. The device has the characteristics of high reoxygenation efficiency, good denitrification and phosphorus removal effect and stable operation.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to an artificial rapid infiltration water purification device. Background Art

[0002] With the improvement of living standards in villages and towns, flush toilets have become popular among farmers, washing water has increased significantly, the amount of domestic water used in communities and the rate of centralized water supply have increased year by year, and the amount of domestic sewage discharged in rural areas has increased year by year. A large amount of domestic sewage is discharged without strict treatment, which has become one of the main causes of environmental pollution problems such as rural environmental pollution, eutrophication of lakes and rivers. Unlike cities, rural areas have relatively scattered populations and large differences in geographical factors, making sewage collection more difficult. Therefore, the methods for rural sewage treatment at home and abroad are more decentralized. However, the more decentralized the treatment, the more treatment facilities need to be built, and the greater the cost, which has led to the economic cost becoming a constraint on the development of rural sewage treatment projects. Therefore, it is particularly important to choose suitable process equipment in rural sewage treatment.

[0003] Land treatment technology is the first sewage treatment method used in rural areas. It is to directly discharge sewage and then diffuse it into the soil through infiltration, and use the microorganisms in the soil and the hierarchical structure of the soil to treat it by physical and biological methods. Artificial rapid infiltration technology, which is developed based on traditional soil infiltration technology, has attracted increasing attention in recent years due to its advantages such as high hydraulic load, low infrastructure cost, and simple operation and maintenance. It is particularly suitable for the treatment of rural decentralized sewage. Artificial rapid infiltration technology usually adopts the method of alternating flooding and drying to achieve natural reoxygenation, and realizes the zoning of oxygen environment by regulating the depth of the filter material. However, due to the relatively low reoxygenation efficiency, relatively short hydraulic retention time, and large fluctuations in water quality and water quantity, the traditional artificial rapid infiltration technology has the disadvantages of low denitrification and phosphorus removal efficiency and unstable operation, which seriously affects the promotion and application of this technology in rural areas. In view of this, the development of an artificial rapid infiltration water purification device with high reoxygenation efficiency, good denitrification and phosphorus removal effect, and stable operation is of great practical significance for the treatment of rural decentralized sewage. Summary of the invention

[0004] In view of the above-mentioned deficiencies or defects, the purpose of the present invention is to provide an artificial rapid infiltration water purification device, which can effectively solve the problems of low reoxygenation efficiency, poor denitrification and phosphorus removal effects and unstable operation in traditional artificial rapid infiltration technology.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention provides an artificial rapid infiltration water purification device, comprising an infiltration tank body, wherein a water distribution area, a gravel area, an aerobic zone one, an aerobic zone two and an aerobic zone three are sequentially arranged on the upper part of the infiltration tank body from top to bottom, and an anoxic zone one, anoxic zone two and ceramsite zone one are arranged on the lower part of the infiltration tank body, the top of the anoxic zone one is connected with the bottom of the aerobic zone three, the anoxic zone one is connected with the anoxic zone two through the ceramsite zone one located at the bottom, and a drainage outlet is arranged on one side of the anoxic zone two.

[0007] Furthermore, the height of the water distribution area is 10 to 20 cm, preferably 15 cm.

[0008] Furthermore, the filler in the gravel area is gravel with a particle size of 0.5 to 1.5 cm and a height of 3 to 10 cm, preferably 5 cm.

[0009] Furthermore, the height of the aerobic zone 1 is 15 to 35 cm, preferably 25 cm.

[0010] Furthermore, the height ratio of the aerobic zone 1, the aerobic zone 2, the aerobic zone 3, the anoxic zone 1 and the anoxic zone 2 is 1-3:1-2:1-2:2-8:2-8, preferably 1:1:1:2:2.

[0011] Furthermore, the filter material of the aerobic zone 1 is natural river sand with a particle size of 0.5 to 1.0 mm.

[0012] Furthermore, the filter material of the aerobic zone 2 is oxygen-releasing particles with a particle size of 1 to 5 mm.

[0013] Furthermore, oxygen-releasing particles are prepared by the following method: magnesium peroxide, cement, natural river sand, bentonite, yellow dextrin, potassium dihydrogen phosphate and citric acid are evenly mixed, water is added at room temperature and stirred until it becomes a paste, and the mixture is poured into a mold and air-dried to obtain oxygen-releasing particles; wherein the mass ratio of magnesium peroxide, cement, natural river sand, bentonite, yellow dextrin, potassium dihydrogen phosphate and citric acid is 6-9:3-6:3-6:1-2:1:1:1, and preferably is 6:5:4:2:1:1:1.

[0014] Furthermore, the filter material of the aerobic zone three is natural river sand with a particle size of 0.3 to 0.8 mm.

[0015] Furthermore, the filter material of the anoxic zone 1 is a uniform mixture of natural river sand and micron zero-valent iron powder in a mass ratio of 7 to 10:1; wherein the mass ratio of natural river sand to micron zero-valent iron powder is preferably 9:1.

[0016] Furthermore, the filter material of the anoxic zone 2 is natural river sand with a particle size of 0.3 to 0.8 mm.

[0017] Furthermore, the filler of the first ceramsite zone is ceramsite with a particle size of 2 to 5 mm and a height of 3 to 10 cm, preferably 5 cm.

[0018] Furthermore, a second ceramsite zone is arranged on the top of the second anoxic zone.

[0019] Furthermore, the filler of the second ceramsite zone is ceramsite with a particle size of 5 to 10 mm, and a height of 3 to 10 cm, preferably 5 cm.

[0020] The present invention has the following advantages:

[0021] 1. High reoxygenation efficiency: Multi-layer composite aerobic zones are used to achieve efficient reoxygenation and promote the occurrence of aerobic reactions. Among them, aerobic zone 1 relies on alternating operation of solid and dry to achieve natural reoxygenation, aerobic zone 2 relies on oxygen-releasing particles to release oxygen to achieve reoxygenation, and aerobic zone 3 relies on the dissolved oxygen carried by sewage flowing through aerobic zone 2 for aerobic reactions;

[0022] 2. Good denitrification and phosphorus removal effects: Ammonia nitrogen in sewage undergoes efficient nitrification in aerobic zone 1, aerobic zone 2 and aerobic zone 3. After entering anoxic zone 1 and anoxic zone 2, not only traditional denitrification but also iron autotrophic denitrification (NO3 - +5Fe 2+ +6H + →0.5N2+5Fe 3+ +3H2O and hydrogen autotrophic denitrification (2NO3 - +5H2+2H + →N2+6H2O), the denitrification efficiency is greatly improved; the phosphorus pollutants in the sewage can be efficiently removed through the adsorption of various filter materials and the transformation of microorganisms on the surface of the filter materials;

[0023] 3. Stable operation: Aerobic zone 1, aerobic zone 2 and aerobic zone 3 are jointly responsible for aerobic biological treatment, and anoxic zone 1 and anoxic zone 2 are jointly responsible for anoxic biological treatment. Multiple guarantees make it highly adaptable to fluctuations in water quality and quantity, and the operation effect is stable;

[0024] 4. In the oxygen-releasing particles of the present invention, magnesium peroxide acts as an oxygen-releasing agent, which can release oxygen after contacting with water; natural river sand acts as a pore-forming agent, increasing the internal voids of the oxygen-releasing particles and further increasing the dissolved oxygen content in the water; cement acts as a plasticizer, bentonite acts as an embedding agent, and yellow dextrin acts as an adhesive. The combination of the three can effectively prevent the integrity of the overall structure of the oxygen-releasing particles, prolong the oxygen release time, and effectively solve the problem of failure of the oxygen-releasing particles caused by the impact of sewage on the overall structure of the oxygen-releasing particles; potassium dihydrogen phosphate and citric acid act as pH buffers. Through the synergistic effect of each component, when the oxygen-releasing particles come into contact with sewage, magnesium peroxide can release oxygen, and the oxygen dissolves in the sewage, which can provide aerobic microorganisms with the dissolved oxygen required to degrade or transform pollutants for a long time and efficiently, thereby improving the reoxygenation efficiency and pollutant removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic structural diagram of an artificial rapid diafiltration water purification device in Example 1 of the present invention;

[0026] Among them, 1. water distribution area; 2. gravel area; 3. aerobic zone 1; 4. aerobic zone 2; 5. aerobic zone 3; 6. anoxic zone 1; 7. anoxic zone 2; 8. expanded clay zone 1; 9. expanded clay zone 2; 10. drainage outlet; 11. infiltration tank body. DETAILED DESCRIPTION

[0027] Example 1

[0028] The present embodiment 1 provides an artificial rapid infiltration water purification device, including an infiltration tank body 11, the upper part of the infiltration tank body 11 is provided with a water distribution area 1, a gravel area 2, an aerobic area 1 3, an aerobic area 2 4 and an aerobic area 3 5 in sequence from top to bottom, the lower part of the infiltration tank body 11 includes an anoxic area 1 6, an anoxic area 2 7 and a ceramsite area 1 8, the top of the anoxic area 1 6 is connected to the bottom of the aerobic area 3 5, the anoxic area 1 6 is connected to the anoxic area 2 7 through the ceramsite area 1 8 located at the bottom, and a drain port 10 is provided on one side of the anoxic area 2 7;

[0029] Among them, the height of water distribution area 1 is 15cm;

[0030] The filler in gravel area 2 is gravel with a particle size of 0.5 to 1.5 cm and a height of 5 cm;

[0031] The height of aerobic zone 3 is 25 cm;

[0032] The height ratio of aerobic zone 1 3, aerobic zone 2 4, aerobic zone 3 5, anoxic zone 1 6 and anoxic zone 2 7 is 1:1:1:2:2;

[0033] The filter material of aerobic zone 3 is natural river sand with a particle size of 0.5 to 1.0 mm;

[0034] The filter material of aerobic zone 2 4 is oxygen-releasing particles with a particle size of 1 to 5 mm;

[0035] The oxygen-releasing particles are prepared by the following method: magnesium peroxide, cement, natural river sand, bentonite, yellow dextrin, potassium dihydrogen phosphate and citric acid are uniformly mixed, water is added at room temperature and stirred until a paste is formed, and the mixture is poured into a mold and air-dried for 24 hours to obtain the oxygen-releasing particles; wherein the mass ratio of magnesium peroxide, cement, natural river sand, bentonite, yellow dextrin, potassium dihydrogen phosphate and citric acid is 6:5:4:2:1:1:1;

[0036] The filter material of aerobic zone 35 is natural river sand with a particle size of 0.3-0.8 mm;

[0037] The filter material of the anoxic zone 6 is a uniform mixture of natural river sand and micron zero-valent iron powder in a mass ratio of 9:1;

[0038] The filter material of the anoxic zone 27 is natural river sand with a particle size of 0.3 to 0.8 mm;

[0039] The filler of the ceramsite zone 8 is ceramsite with a particle size of 2 to 5 mm and a height of 5 cm;

[0040] A ceramsite zone 2 9 is provided on the top of the anoxic zone 2 7;

[0041] The filler of the ceramsite zone 2 9 is ceramsite with a particle size of 5 to 10 mm and a height of 5 cm.

[0042] Example 2

[0043] This embodiment 2 provides an artificial rapid infiltration water purification device, which differs from the embodiment 1 only in that the height ratio of aerobic zone 1 3, aerobic zone 2 4, aerobic zone 3 5, anoxic zone 1 6 and anoxic zone 2 7 is 2:2:2:5:5, and the other parameters are the same.

[0044] Example 3

[0045] This embodiment 3 provides an artificial rapid infiltration water purification device, which is different from the embodiment 1 only in that the height ratio of aerobic zone 1 3, aerobic zone 2 4, aerobic zone 3 5, anoxic zone 1 6 and anoxic zone 2 7 is 3:2:2:8:8, and the other parameters are the same.

[0046] Example 4

[0047] This embodiment 4 provides an artificial rapid infiltration water purification device, which is different from the embodiment 1 only in that the height of the water distribution area 1 is 10 cm, the height of the gravel area 2 is 10 cm, and the other parameters are the same.

[0048] Comparative Example 1

[0049] This comparative example 1 provides an artificial rapid diafiltration water purification device, which differs from Example 1 only in that: the filter material oxygen-releasing particles in the aerobic zone 2 4 are prepared by the following method: calcium peroxide, diatomaceous earth, yellow dextrin, potassium persulfate and citric acid are mixed evenly, water is added at room temperature and stirred until it becomes a paste, and the mixture is poured into a mold and air-dried for 24 hours to obtain oxygen-releasing particles; wherein the mass ratio of calcium peroxide, cement, natural river sand, diatomaceous earth, yellow dextrin, potassium persulfate and citric acid is 6:5:4:2:1:1:1; and the other parameters are the same.

[0050] Comparative Example 2

[0051] This comparative example 2 provides an artificial rapid infiltration water purification device, which is different from the embodiment 1 only in that the height ratio of aerobic zone 1 3, aerobic zone 2 4, aerobic zone 3 5, anoxic zone 1 6 and anoxic zone 2 7 is 5:1:7:11:10, and the other parameters are the same.

[0052] Experimental Example 1

[0053] The domestic sewage of a rural area in Chengdu was taken as the treatment object, and the influent water quality was as follows: ρ(COD)=283~319mg / L, ρ(BOD5)=204~258mg / L, ρ(NH4 + -N)=47~59mg / L, ρ(TN)=52~65mg / L, ρ(TP)=3.6~4.9mg / L, pH=6~9. The sewage entered the artificial rapid diafiltration water purification device obtained in Example 1 and Comparative Examples 1-2 and operated for 90 days respectively. The operating conditions were: wet-to-dry ratio 1:3, hydraulic load 0.8~1.5m / d, and ambient temperature 18~35℃. The 90-day operation results showed that the artificial rapid diafiltration water purification device obtained in Example 1: effluent ρ(COD)≤50mg / L, ρ(BOD5)≤10mg / L, ρ(NH4 + -N)≤5mg / L, ρ(TN)≤15mg / L, ρ(TP)≤0.5mg / L, pH=6~9, the effluent water quality indicators all meet the Class A standard of "Pollutant Discharge Standard for Urban Sewage Treatment Plants" (GB 18918-2002), the operation is stable, and the effluent effect is good; while the effluent water quality indicators of the artificial rapid diafiltration water purification devices obtained in Comparative Examples 1 and 2 do not meet the Class A standard of "Pollutant Discharge Standard for Urban Sewage Treatment Plants" (GB 18918-2002). Among them, the artificial rapid diafiltration water purification device obtained in Comparative Example 1: effluent ρ(COD)=114mg / L, ρ(BOD5)=98mg / L, ρ(NH4 + -N)=25mg / L、ρ(TN)=35mg / L、ρ(TP)=2.5mg / L、pH=6~9; The oxygen-releasing particles in Comparative Example 1 lack natural river sand as a pore-forming agent, which greatly reduces the internal pores and reduces the reoxygenation efficiency. The impact resistance of the overall structure of the oxygen-releasing particles in sewage is also greatly weakened, resulting in a decrease in the sewage treatment effect; The artificial rapid infiltration water purification device in Comparative Example 2: the effluent ρ(COD)=95mg / L、ρ(BOD5)=95mg / L、ρ(NH4 + -N)=18mg / L, ρ(TN)=21mg / L, ρ(TP)=2.0mg / L, pH=6~9; Since the aerobic zone 1 is close to the water inlet, it relies on the air entering the filter material during the drying period to achieve reoxygenation. If the height of this area is too large or too small, the reoxygenation efficiency will be reduced; The aerobic zone 2 uses oxygen-releasing particles as filter material, and relies on the oxygen-releasing particles to release oxygen to achieve reoxygenation. The oxygen concentration in this area is the largest. If the height is too small or too large, the dissolved oxygen content in the entire aerobic zone will be too high or too low. When it is too low, it will affect the nitrification process of ammonia nitrogen in the sewage. When it is too high, it will affect the denitrification process of the subsequent anaerobic zone; The aerobic zone 3 uses natural river sand as filter material, and relies on the dissolved oxygen from the aerobic zone 2 carried by the sewage to achieve reoxygenation. When the height of this area is too large, the nitrification process of ammonia nitrogen in this area will occur due to the low dissolved oxygen content.

[0054] The above contents are merely examples and explanations of the structure of the present invention. Any modification or supplement made to the described specific embodiments or replacement by similar methods by technicians in the relevant field without creative work still falls within the scope of protection of this patent.

Claims

1. An artificial rapid filtration water purification device, characterized in that: The invention comprises a percolation pond body (11), wherein the upper part of the percolation pond body (11) is provided with a water distribution area (1), a gravel area (2), an aerobic area 1 (3), an aerobic area 2 (4) and an aerobic area 3 (5) in order from top to bottom, and the lower part of the percolation pond body (11) comprises an anoxic area 1 (6), anoxic area 2 (7) and a ceramsite area 1 (8), wherein the top of the anoxic area 1 (6) is connected to the bottom of the aerobic area 3 (5), the anoxic area 1 (6) is connected to the anoxic area 2 (7) via the ceramsite area 1 (8) located at the bottom, and a drainage port (10) is provided on one side of the anoxic area 2 (7); Wherein, the height of the aerobic zone 1 (3) is 15-35 cm; The height ratio of the aerobic zone 1 (3), the aerobic zone 2 (4), the aerobic zone 3 (5), the anoxic zone 1 (6) and the anoxic zone 2 (7) is 1-3:1-2:1-2:2-8:2-8; The filter material of the aerobic zone 1 (3) is natural river sand with a particle size of 0.5-1.0 mm; The filter material of the aerobic zone 2 (4) is oxygen-releasing particles with a particle size of 1 to 5 mm, and the filter material of the aerobic zone 3 (5) is natural river sand with a particle size of 0.3 to 0.8 mm; The oxygen-releasing particles are prepared by the following method: magnesium peroxide, cement, natural river sand, bentonite, yellow dextrin, potassium dihydrogen phosphate and citric acid are uniformly mixed, water is added at room temperature and stirred until the mixture is in a paste state, and the mixture is poured into a mold and air-dried to obtain oxygen-releasing particles; wherein the mass ratio of magnesium peroxide, cement, natural river sand, bentonite, yellow dextrin, potassium dihydrogen phosphate and citric acid is 6-9:3-6:3-6:1-2:1:1:1; The filter material of the anoxic zone one (6) is a mixture of natural river sand and micron-grade zero-valent iron powder in a mass ratio of 7 to 10:1, and the filter material of the anoxic zone two (7) is natural river sand with a particle size of 0.3 to 0.8 mm.

2. The artificial rapid infiltration water purification device according to claim 1, characterized in that: The height of the water distribution area (1) is 10-20 cm.

3. The artificial rapid infiltration water purification device according to claim 1, characterized in that: The filler of the gravel area (2) is gravel with a particle size of 0.5 to 1.5 cm and a height of 3 to 10 cm.

4. The artificial rapid infiltration water purification device according to claim 1, characterized in that: The filler of the ceramsite zone 1 (8) is ceramsite with a particle size of 2 to 5 mm and a height of 3 to 10 cm; a ceramsite zone 2 (9) is arranged on the top of the anoxic zone 2 (7).

5. The artificial rapid infiltration water purification device according to claim 4, characterized in that: The filler of the expanded clay zone 2 (9) is expanded clay with a particle size of 5 to 10 mm and a height of 3 to 10 cm.

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