CN111333268B

CN111333268B - Efficient purification system and purification method for domestic sewage

Info

Publication number: CN111333268B
Application number: CN202010166636.9A
Authority: CN
Inventors: 景江; 彭靖; 范天斌; 张欣; 马海曲干; 潘祖浩; 牟潇丽; 袁壮; 吴柟岚; 卜昕宇; 王路阳; 火补此聪
Original assignee: Chengdu Univeristy of Technology
Current assignee: Chengdu Univeristy of Technology
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2021-03-16
Anticipated expiration: 2040-03-11
Also published as: CN111333268A

Abstract

The invention discloses a high-efficiency purification system and purification method for domestic sewage. The purification device comprises a filter tank, an ecological tank, an electrolysis tank, an anaerobic tank and a retention tank which are connected in sequence from left to right, and a water inlet pipe is arranged at the bottom of the filter tank , the filter tank is provided with a filter device, the ecological tank is provided with a gravel layer, a grass residue layer, a broken wood layer, a volcanic stone layer and a zeolite layer in sequence from top to bottom, and duckweed is planted in the gravel layer; A soil layer 1, a carbon residue layer, a soil layer 2 and a steel wire mesh layer are arranged. The interception pond is provided with a soil layer 3, an interception layer and an activated carbon layer in sequence from top to bottom. There are drainage pipes, the filter tank and the ecological tank are at the same level, and the electrolytic tank, the anaerobic tank and the retention tank are at the same level and lower than the filter tank. The purification device and method can effectively remove the pollutants in the domestic sewage and realize the effect of water purification.

Description

Efficient purification system and purification method for domestic sewage

Technical Field

The invention belongs to the technical field of domestic sewage purification, and particularly relates to a high-efficiency domestic sewage purification system and a purification method

Background

With the national emphasis on point-source pollution caused by industrial sewage discharge, agricultural sewage pollution and rural domestic sewage pollution have gradually become the main sources of river water eutrophication. The nitrogen and phosphorus content of the water body is higher, which causes massive growth of algae and death of a large amount of aquatic plants and fishes. The rural domestic sewage is sewage generated by washing, bathing, kitchen cooking, excrement and urine, flushing and the like in households in villages and towns. Rural domestic sewage has the characteristics of wide spread, multiple sources, quick growth, complex sewage components and large change of water quality and water quantity, is difficult to collect and manage, and causes a plurality of ecological environment problems. Therefore, the strengthening of the collection, treatment and resource utilization of the rural domestic sewage is an irreparable task in building new socialist rural areas.

At present, a plurality of domestic sewage purification devices are provided, and a common purification device can effectively remove COD (chemical oxygen demand), BOD (biochemical oxygen demand) and the like in sewage to meet the standard requirements, but the removal efficiency of the existing device is lower for total nitrogen and total phosphorus, and the total nitrogen and total phosphorus content in the purified water body cannot meet the national standard requirements.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a high-efficiency purification method and a purification device for domestic sewage, and the purification method can effectively solve the problem of poor nitrogen and phosphorus removal effect in the existing purification method.

In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows:

a high-efficiency purification system for domestic sewage comprises a filter tank, an ecological tank, an electrolytic tank, an anaerobic tank and a retention tank which are sequentially communicated from left to right, wherein a water inlet pipe is arranged at the bottom of the filter tank, a filter device is arranged in the filter tank, a gravel layer, a grass residue layer, a crushed wood layer, a volcanic stone layer and a zeolite layer are sequentially arranged in the ecological tank from top to bottom, and duckweeds are planted in the gravel layer;

the electrolytic cell has the advantages that the first soil layer, the carbon slag layer, the second soil layer and the steel wire mesh layer are sequentially arranged in the electrolytic cell from top to bottom, the third soil layer, the interception layer and the activated carbon layer are sequentially arranged in the interception cell from top to bottom, aquatic plants are planted in the third soil layer, the interception cell bottom is provided with the drain pipe, the filtering cell and the ecological cell are at the same level, and the electrolytic cell, the anaerobic cell and the interception cell are at the same level and are lower than the filtering cell.

The beneficial effects produced by adopting the scheme are as follows: after the sewage enters the filtering tank, large-particle pollutants in the sewage are filtered under the filtering action of the filtering device, the water level in the filtering tank gradually rises and flows into the ecological tank, a large number of anaerobic-facultative anaerobic microorganisms are attached to the surfaces of grass residues and broken wood in the ecological tank, a large number of aerobic microorganisms are also attached to the root system of duckweed, the root system of the duckweed extends into a grass residue layer and a broken wood layer, a nitrogen and phosphorus removal system is formed among the grass residue layer, the broken wood layer and the root system of the duckweed, partial nitrogen and phosphorus elements are removed by the decomposition action of the anaerobic-alkaline anaerobic microorganisms in the system, and a part of nitrogen and phosphorus elements are removed by the absorption and adsorption action of the duckweed, and a gravel layer is arranged on the upper part of the grass residue layer, so that the compression and fixation effect on the grass residues can be achieved, the grass residues are prevented from floating on the water surface, and a certain filtering effect;

the sewage further falls into the volcanic rock layer and the zeolite layer, the volcanic rock has the advantages of rough surface and large porosity, the volcanic rock can absorb nitrogen and phosphorus, and has good film-forming performance, microorganisms formed in the grass residue layer and the broken wood layer flow into the volcanic rock layer under the action of water flow, stay in gaps of the volcanic rock under the absorption action of the volcanic rock, and form a layer of biomembrane on the surface of the volcanic rock after certain time accumulation, and when the water flow passes through, the biomembrane can digest and decompose organic substances in the water body, so that the purpose of purifying the water body is achieved; meanwhile, the volcanic rock surface has positive charges, so that metal ions in the sewage can be adsorbed through the adsorption effect of the charges, and the sewage purification effect is further improved.

The sewage continuously flows into the electrolytic cell, the soil layer I at the upper part of the electrolytic cell is used for planting aquatic plants, and pollutants such as nitrogen, phosphorus and the like in the water body are adsorbed by the aquatic plants; after the water flowed into the carbon residue layer, carried the intraformational carbon element of carbon residue and continued the circulation downwards through soil horizon two and wire net layer, when sewage and the intraformational wire net contact of wire net, carbon element in the water and the iron element in the wire net take place the little electrolysis of iron carbon for form 1.2 v's potential difference between carbon residue layer, soil horizon two and the wire net layer, utilize the little electrolysis of iron carbon to carry out electrolytic treatment to the pollutant in the sewage, reach the purpose of degradation pollutant.

The water body continues to flow into the anaerobic tank, under the anaerobic condition, nitrate nitrogen elements in the sewage are reduced into nitrogen, the nitrogen is dissipated into the atmosphere, the purpose of removing the nitrogen elements is achieved, finally, the sewage enters the interception tank, the interception layer is made of dried sludge obtained after sewage purification by a sludge treatment plant is dried and treated, a large amount of flocculation active ingredients are contained, after the water body passes through the interception tank, most nitrogen and phosphorus elements in the sewage can be intercepted by utilizing the adsorption electric neutralization effect, the adsorption bridging effect, the compression electric double layer effect and the like of the dried sludge, then under the interception and adsorption effects of the active carbon, nitrogen and phosphorus elements in the sewage are further adsorbed, elements such as nitrogen and phosphorus adsorbed in the interception layer can be fully absorbed and utilized by aquatic plants in the soil layer III, and the finally discharged water body is enabled to have the nitrogen and phosphorus element content compounded national sewage discharge standard.

Further, the filter device is a polyester fiber filter screen, and the polyester fiber filter screen is at least provided with 3 layers.

The beneficial effects produced by adopting the scheme are as follows: the edge of polyester fiber filter screen is connected with the filtering ponds through the frame, improves the convenience of use, sets up the polyester fiber filter screen into 3 layers at least, can improve filterable effect, effectively holds back the large granule pollutant in the water.

Furthermore, the thickness of the gravel layer, the straw slag layer and the crushed wood layer in the ecological pool is 10-20 cm, and the thickness of the volcanic stone layer and the zeolite layer is 20-40 cm.

The beneficial effects produced by adopting the scheme are as follows: the height can improve the degradation effect of a microbial ecosystem formed among the rice straw layer, the crushed wood layer and the volcanic stone layer and promote the decomposition and removal efficiency of pollutants in the water body; the thickness of the volcanic stone layer is set to be larger, so that the area of a biological film formed in the volcanic stone layer can be effectively increased, and the pollutant removal effect is further improved.

Furthermore, the duckweed in the ecological pond is duckweed.

The beneficial effects produced by adopting the scheme are as follows: the root system of the spirodela polyrhiza can effectively absorb nitrogen and phosphorus elements of nutrient substances in the water body, the dissolved oxygen amount in the water body can be effectively increased, the pH value of the water body is stabilized, a large number of microorganisms are attached to the root system, and the microorganisms are more favorable for removing the nitrogen elements in the water body in a nitrification and denitrification mode so as to improve the water body purification effect.

Furthermore, the thickness of the first soil layer and the carbon residue layer in the electrolytic cell is 20-30 cm, aquatic plants are planted in the first soil layer, and the thickness of the second soil layer is 10-20 cm.

The beneficial effects produced by adopting the scheme are as follows: the thickness of the carbon slag layer is set to be 20-30 cm, and after the water flows through, the carrying amount of carbon elements in the water can be fully increased, so that iron-carbon micro-electrolysis is generated between the carbon elements and the steel wire mesh, the electrolysis effect of organic matters is improved, and the purification effect of the water is improved.

Furthermore, a quartz sand layer is arranged in the electrolysis area, the quartz sand layer is arranged on the lower portion of the steel wire mesh layer, and the thickness of the quartz sand layer is 15-30 cm.

The beneficial effects produced by adopting the scheme are as follows: the quartz sand layer can further filter pollutants in the water body, and the clarity of the effluent in the electrolytic cell is improved.

Further, an anaerobic activated granular sludge layer is arranged in the anaerobic tank.

The beneficial effects produced by adopting the scheme are as follows: the anaerobic activated granular sludge layer contains a large amount of facultative anaerobes, so that the sewage entering the anaerobic tank can be subjected to denitrification rapidly under the action of the facultative anaerobes, nitrate nitrogen is reduced into nitrogen and is dissipated into the atmosphere, and the nitrogen element is further removed.

Furthermore, the thickness of the soil layer III in the interception tank is 10-15 cm, the thickness of the interception layer is 20-40 cm, and the thickness of the activated carbon layer is 20-30 cm.

The beneficial effects produced by adopting the scheme are as follows: it has aquatic plant to plant in soil horizon three, soil horizon three plays fixed effect to the plant, the plant is at the growth in-process, the root system constantly deepens deeply and holds back the in situ, adsorb and hold back intraformational nitrogen phosphorus element, the thickness that will hold back the layer sets up to 20-40 centimetres, the nitrogen phosphorus element that this thickness was held back can fully satisfy the absorption utilization of plant, moreover, this thickness also is moderate with the length of plant root system, do benefit to the extension of root system, the thickness on activated carbon layer sets up to 20-30 centimetres, can effectively absorb remaining nitrogen phosphorus element in the sewage, improve the quality of drainage, make it accord with national emission standard.

Furthermore, the aquatic plants in the interception tank are allium mongolicum regel, reed, juncus effuses or canna indica.

The beneficial effects produced by adopting the scheme are as follows: the aquatic plant has strong absorption and adsorption performance on nitrogen and phosphorus elements, and can improve the purification effect of sewage.

A high-efficiency purification method of rural domestic sewage comprises the following steps:

(1) planting duckweed in the ecological pond, and planting aquatic plants in the interception pond;

(2) discharging domestic sewage into a filtering tank through a water inlet pipe, and enabling the sewage to flow into an ecological tank through the upper part of the filtering tank after the water level reaches a certain height;

(3) sewage in the ecological pool sequentially passes through a gravel layer, a grass residue layer, a crushed wood layer, a volcanic stone layer and a zeolite layer from top to bottom and then enters the electrolytic pool from the bottom of the ecological pool;

(4) sewage in the electrolytic tank sequentially passes through a soil layer I, a carbon residue layer, a soil layer II and a steel wire mesh layer from top to bottom and then enters the anaerobic tank from the bottom of the electrolytic tank;

(5) the sewage level in the anaerobic tank gradually rises and then enters the interception tank from the upper part of the anaerobic tank;

(6) sewage in the interception tank sequentially passes through the soil layer III, the interception layer and the activated carbon layer from top to bottom and is finally discharged through a drain pipe at the bottom of the interception tank, so that purification is realized.

The invention has the following beneficial effects:

1. the invention is provided with a filter tank, large-particle pollutants in sewage are preliminarily filtered under the filtering action of the filter tank, the ecological tank is arranged, duckweed is planted at the upper part of the ecological tank, the ecological tank also comprises a grass residue layer and a crushed wood layer, a large number of anaerobic-facultative anaerobic microorganisms are attached to the surfaces of the root system of the duckweed, the grass residue layer and the crushed wood layer, a volcanic layer arranged at the lower part of the crushed wood layer adsorbs microorganisms brought down by water flow, biological membranes are formed on the surface and in gaps of volcanic rocks, various microorganism systems are formed in the surfaces of the duckweed, the grass residue layer, the crushed wood layer and the volcanic rock layer, and after water flows through the microorganism systems, a large number of pollutants such as nitrogen and phosphorus, BOD, COD (chemical oxygen demand), heavy metal and the like in water are quickly removed through the degradation action of the microorganisms in the microorganism systems and.

2. After the water body enters the electrolytic cell, under the action of iron-carbon micro-electrolysis in the electrolytic cell, organic pollutants in the water body can be degraded in a micro-electrolysis mode, aquatic plants are planted in the electrolytic cell, and the water body can be further purified by utilizing the absorption and adsorption effects of the aquatic plants. The water body enters the anaerobic tank, and the residual nitrate nitrogen in the water body is converted into nitrogen to be dissipated through the denitrification of anaerobic bacteria in the anaerobic activated sludge particles in the anaerobic tank, so that the nitrogen element is further removed.

3. Contain a large amount of effective components of flocculation in the entrapment layer in the entrapment pond, through the absorption electricity neutralization effect of entrapment layer, adsorption bridging effect and compression electric double layer effect etc. intercept most nitrogen phosphorus element in the sewage to by aquatic plant absorption utilization, through the plant of reaping of periodicity, reach the purpose of cutting down nitrogen phosphorus pollutant in the sewage, finally, adsorption of the residual pollutant in with the water through the adsorption of active carbon for the water of emission accords with national standard.

4. According to the invention, the filtering tank, the ecological tank, the electrolytic tank, the anaerobic tank and the interception tank are used in a combined manner, and pollutants in the wastewater are sufficiently removed through the processes of multi-stage filtration, adsorption, degradation, plant absorption and the like, so that the purification effect of the wastewater is improved.

5. The purification system has the advantages of low energy consumption, low maintenance cost and simple operation, and can be used as a landscape to beautify the environment.

Drawings

FIG. 1 is a schematic diagram of the system;

reference numerals: 1. a filtration tank; 2. an ecological pool; 3. an electrolytic cell; 4. an anaerobic tank; 5. an interception pool; 6. a water inlet pipe; 7. a filtration device; 8. a gravel layer; 9. a grass residue layer; 10. a layer of shredded wood; 11. a volcanic rock layer; 12. a zeolite layer; 13. a first soil layer; 14. a carbon slag layer; 15. a second soil layer; 16. a steel wire mesh layer; 17. a soil layer III; 18. a trapping layer; 19. an activated carbon layer; 20. a drain pipe; 21. a quartz sand layer; 22. anaerobic activated granular sludge blanket.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

Example 1

As shown in figure 1, the high-efficiency purification system for domestic sewage is provided, and comprises a filter tank 1, an ecological tank 2, an electrolytic tank 3, an anaerobic tank 4 and a retention tank 5 which are sequentially communicated from left to right, wherein a water inlet pipe 6 is arranged at the bottom of the filter tank 1, a filter device 7 is arranged in the filter tank 1, and optimally, the filter device 7 is a polyester fiber filter screen, and the polyester fiber filter screen is at least provided with 3 layers. A gravel layer 8, a grass residue layer 9, a crushed wood layer 10, a volcanic rock layer 11 and a zeolite layer 12 are sequentially arranged in the ecological pool 2 from top to bottom, and duckweeds are planted in the gravel layer 8; optimally, the thickness of the gravel layer 8, the grass residue layer 9, the crushed wood layer 10 and the volcanic stone layer 11 in the ecological pool 2 is 10 cm, and the thickness of the zeolite layer 12 is 20 cm. Optimally, the duckweed in the ecological pool 2 is the duckweed.

The electrolytic cell 3 is internally provided with a soil layer I13, a carbon residue layer 14, a soil layer II 15 and a steel wire mesh layer 16 from top to bottom in sequence, the thickness of the soil layer I13 and the carbon residue layer 14 in the electrolytic cell 3 is 20 cm, aquatic plants are planted in the soil layer I13, and the thickness of the soil layer II 15 is 10 cm. Optimally, a quartz sand layer 21 is further arranged in the electrolytic cell 3, the quartz sand layer 21 is arranged at the lower part of the steel wire mesh layer 16, and the thickness of the quartz sand layer 21 is 15 cm.

Optimally, an anaerobic activated granular sludge blanket 22 is disposed within the anaerobic tank 4. The intercepting tank 5 is internally provided with a soil layer III 17, an intercepting layer 18 and an activated carbon layer 19 from top to bottom in sequence, aquatic plants are planted in the soil layer III 17, the bottom of the intercepting tank 5 is provided with a drain pipe 20, the filtering tank 1 and the ecological tank 2 are at the same horizontal height, and the electrolytic tank 3, the anaerobic tank 4 and the intercepting tank 5 are at the same horizontal height and are lower than the filtering tank 1. Optimally, the thickness of the soil layer III 17 in the interception pool 5 is 10 cm, the thickness of the interception layer 18 is 20 cm, and the thickness of the activated carbon layer 19 is 20 cm. Optimally, the aquatic plant in the interception tank 5 is canna.

Example 2

As shown in figure 1, the high-efficiency purification system for domestic sewage is provided, and comprises a filter tank 1, an ecological tank 2, an electrolytic tank 3, an anaerobic tank 4 and a retention tank 5 which are sequentially communicated from left to right, wherein a water inlet pipe 6 is arranged at the bottom of the filter tank 1, a filter device 7 is arranged in the filter tank 1, and optimally, the filter device 7 is a polyester fiber filter screen, and the polyester fiber filter screen is provided with at least 3 layers. A gravel layer 8, a grass residue layer 9, a crushed wood layer 10, a volcanic rock layer 11 and a zeolite layer 12 are sequentially arranged in the ecological pool 2 from top to bottom, and duckweeds are planted in the gravel layer 8; optimally, the thickness of the gravel layer 8, the grass residue layer 9, the crushed wood layer 10 and the volcanic stone layer 11 in the ecological pool 2 is 15 cm, and the thickness of the zeolite layer 12 is 30 cm. Optimally, the duckweed in the ecological pool 2 is the duckweed.

The electrolytic cell 3 is internally provided with a soil layer I13, a carbon residue layer 14, a soil layer II 15 and a steel wire mesh layer 16 from top to bottom in sequence, the thickness of the soil layer I13 and the carbon residue layer 14 in the electrolytic cell 3 is 25 cm, aquatic plants are planted in the soil layer I13, and the thickness of the soil layer II 15 is 15 cm. Optimally, a quartz sand layer 21 is further arranged in the electrolytic cell 3, the quartz sand layer 21 is arranged at the lower part of the steel wire mesh layer 16, and the thickness of the quartz sand layer 21 is 20 cm.

Optimally, an anaerobic activated granular sludge blanket 22 is disposed within the anaerobic tank 4. The intercepting tank 5 is internally provided with a soil layer III 17, an intercepting layer 18 and an activated carbon layer 19 from top to bottom in sequence, aquatic plants are planted in the soil layer III 17, the bottom of the intercepting tank 5 is provided with a drain pipe 20, the filtering tank 1 and the ecological tank 2 are at the same horizontal height, and the electrolytic tank 3, the anaerobic tank 4 and the intercepting tank 5 are at the same horizontal height and are lower than the filtering tank 1. Optimally, the thickness of the soil layer III 17 in the interception pool 5 is 15 cm, the thickness of the interception layer 18 is 30 cm, and the thickness of the activated carbon layer 19 is 25 cm. Optimally, the aquatic plant in the interception pool 5 is the allium fistulosum.

Example 3

As shown in figure 1, the high-efficiency purification system for domestic sewage is provided, and comprises a filter tank 1, an ecological tank 2, an electrolytic tank 3, an anaerobic tank 4 and a retention tank 5 which are sequentially communicated from left to right, wherein a water inlet pipe 6 is arranged at the bottom of the filter tank 1, a filter device 7 is arranged in the filter tank 1, and optimally, the filter device 7 is a polyester fiber filter screen, and the polyester fiber filter screen is provided with at least 3 layers. A gravel layer 8, a grass residue layer 9, a crushed wood layer 10, a volcanic rock layer 11 and a zeolite layer 12 are sequentially arranged in the ecological pool 2 from top to bottom, and duckweeds are planted in the gravel layer 8; optimally, the thickness of the gravel layer 8, the grass residue layer 9, the crushed wood layer 10 and the volcanic stone layer 11 in the ecological pool 2 is 20 cm, and the thickness of the zeolite layer 12 is 40 cm. Optimally, the duckweed in the ecological pool 2 is the duckweed.

The electrolytic cell 3 is internally provided with a soil layer I13, a carbon residue layer 14, a soil layer II 15 and a steel wire mesh layer 16 from top to bottom in sequence, the thickness of the soil layer I13 and the carbon residue layer 14 in the electrolytic cell 3 is 30 cm, aquatic plants are planted in the soil layer I13, and the thickness of the soil layer II 15 is 20 cm. Optimally, a quartz sand layer 21 is further arranged in the electrolytic cell 3, the quartz sand layer 21 is arranged at the lower part of the steel wire mesh layer 16, and the thickness of the quartz sand layer 21 is 30 cm.

Optimally, an anaerobic activated granular sludge blanket 22 is disposed within the anaerobic tank 4. The intercepting tank 5 is internally provided with a soil layer III 17, an intercepting layer 18 and an activated carbon layer 19 from top to bottom in sequence, aquatic plants are planted in the soil layer III 17, the bottom of the intercepting tank 5 is provided with a drain pipe 20, the filtering tank 1 and the ecological tank 2 are at the same horizontal height, and the electrolytic tank 3, the anaerobic tank 4 and the intercepting tank 5 are at the same horizontal height and are lower than the filtering tank 1. Optimally, the thickness of the soil layer III 17 in the interception pool 5 is 15 cm, the thickness of the interception layer 18 is 40 cm, and the thickness of the activated carbon layer 19 is 30 cm. Optimally, the aquatic plants in the interception tank 5 are rush.

Test examples

The domestic sewage in the same area is purified by adopting the water purification system and the method which are operated for half a year in the examples 1-3 respectively, the pollutant content in the sewage before and after purification is measured respectively, and the specific measurement result is shown in the table 1.

Table 1: pollutant content meter in sewage

According to the above table, the pollutants in the domestic sewage purified by the system and the method of the invention can be effectively removed, and the purified water body can reach the discharge standard.

The purification system has the advantages of low maintenance cost, low power consumption, simple and convenient operation and management and the like, and plants are planted in the ecological tank, the electrolytic tank and the interception tank, so that the sewage purification effect can be realized, the ecological tank can be used as a landscape, and the attractiveness of the environment is improved.

Claims

1. a high-efficiency purification system for domestic sewage, is characterized in that, comprises filter tank (1), ecological tank (2), electrolytic tank (3), anaerobic tank (4) and interception tank that are communicated successively from left to right (5), the bottom of the filter tank (1) is provided with a water inlet pipe (6), the filter tank (1) is provided with a filter device (7), and the ecological tank (2) is sequentially arranged from top to bottom There are a gravel layer (8), a grass residue layer (9), a broken wood layer (10), a volcanic stone layer (11) and a zeolite layer (12), and duckweed is planted in the gravel layer (8);

The electrolytic cell (3) is provided with a soil layer (13), a carbon residue layer (14), a soil layer two (15) and a steel mesh layer (16) in sequence from top to bottom, and the electrolytic cell (3) The thickness of the soil layer one (13) and the carbon residue layer (14) is 20-30 cm, aquatic plants are planted in the soil layer one (13), and the thickness of the soil layer two (15) is 10 cm. -20 cm;

The interception pond (5) is provided with soil layer three (17), interception layer (18) and activated carbon layer (19) in sequence from top to bottom, and aquatic plants are planted in the soil layer three (17). A drain pipe (20) is provided at the bottom of the retention pond (5), the filter pond (1) and the ecological pond (2) are at the same level, and the electrolytic pond (3), the anaerobic pond (4) and the retention pond ( 5) At the same level and below the filter tank (1).

2 . The high-efficiency purification system for domestic sewage according to claim 1 , wherein the filter device ( 7 ) is a polyester fiber filter screen, and the polyester fiber filter screen is provided with at least three layers. 3 .

3 . The high-efficiency purification system for domestic sewage according to claim 1 , wherein the thickness of the gravel layer ( 8 ), the grass residue layer ( 9 ) and the broken wood layer ( 10 ) in the ecological pool ( 2 ) Both are 10-20 cm, and the thicknesses of the volcanic stone layer (11) and the zeolite layer (12) are both 20-40 cm.

4. The high-efficiency purification system for domestic sewage according to claim 1, characterized in that, the duckweed in the ecological pool (2) is Z. chinensis.

5 . The high-efficiency purification system for domestic sewage according to claim 4 , wherein a quartz sand layer ( 21 ) is also arranged in the electrolytic cell ( 3 ), and the quartz sand layer ( 21 ) is arranged on the steel wire. 6 . In the lower part of the mesh layer (16), the thickness of the quartz sand layer (21) is 15-30 cm.

6 . The high-efficiency purification system for domestic sewage according to claim 1 , wherein an anaerobic activated granular sludge layer ( 22 ) is arranged in the anaerobic tank ( 4 ). 7 .

7. The high-efficiency purification system for domestic sewage according to claim 1, wherein the thickness of the soil layer three (17) in the retention tank (5) is 10-15 cm, and the retention layer (18) has a thickness of 10-15 cm. The thickness of the activated carbon layer (19) is 20-40 cm, and the thickness of the activated carbon layer (19) is 20-30 cm.

8 . The high-efficiency purification system for domestic sewage according to claim 7 , wherein the aquatic plants in the retention pond ( 5 ) are shallots, reeds, rushes or canna. 9 .

9. A method for efficient purification of rural domestic sewage, characterized in that, comprising the following steps:

(1) Planting Radix chinensis in the ecological pond, and planting aquatic plants in the retention pond;

(2) Discharge the domestic sewage into the filter tank through the water inlet pipe, and after the water level reaches a certain height, the sewage flows into the ecological tank through the upper part of the filter tank;

(3) The sewage in the ecological pool enters the electrolytic cell from the bottom of the ecological pool after passing through the gravel layer, the grass residue layer, the broken wood layer, the volcanic stone layer and the zeolite layer in sequence from top to bottom;

(4) The sewage in the electrolytic cell enters the anaerobic tank from the bottom of the electrolytic cell after passing through the soil layer one, the carbon residue layer, the soil layer two and the steel mesh layer in sequence from top to bottom;

(5) The sewage water level in the anaerobic tank gradually rises and enters the retention tank from the upper part of the anaerobic tank;

(6) The sewage in the interception tank passes through the soil layer three, the interception layer and the activated carbon layer in sequence from top to bottom, and finally is discharged through the drainage pipe at the bottom of the interception tank to achieve purification.