CN105923891A - Multistage vertical current constructed wetland system-based sewage treatment method - Google Patents

Abstract

The invention discloses a sewage treatment method based on a multi-stage vertical flow artificial wetland system. The artificial wetland system is set up as five compartments, and a sewage allocation pool is arranged at the water inlet of the first compartment, and then the sewage is adsorbed by an external pump to the diversion chamber, and enter the sewage adjustment pool through the water inlet pipe. After the sewage is settled in the sewage allocation pool, the sludge and the primary sewage are separated, and then the primary sewage is introduced into the above-mentioned 5 compartments respectively. The 5 compartments are respectively equipped with water quality Pollutant concentration detector and water level gauge, the sewage treated by the above five chambers enters the detection station, and the water that does not meet the standard is flowed into the upward pool of the first chamber through the underground pipeline to continue to circulate until it meets the standard and then discharged. The present invention has simple structure, remarkable treatment effect on sewage, not only occupies a small area, but also has low operation cost and input cost, and is suitable for large-scale application. The sewage can be recycled and the occurrence of "eutrophication" pollution and other problems can be reduced. .

Description

A sewage treatment method based on a multi-stage vertical flow constructed wetland system

technical field

The invention relates to a sewage treatment method based on a multi-stage vertical flow artificial wetland system.

Background technique

Water resources are basic natural resources and one of the controlling factors of the ecological environment. With the development of the global economy and society and the rapid growth of population, the shortage of water resources has become the focus of the world's attention. Coupled with the destructive exploitation of water areas, irrational use and the discharge of a large number of pollutants, the water quality continues to deteriorate, and many places have Crisis of severe water shortage.

In recent years, various water treatment technologies have achieved continuous development in practical applications, especially the activated sludge process for secondary treatment. The process is relatively mature, but the operating cost is high, and the main purpose is to remove carbon source pollutants. The removal of nutrients such as nitrogen and phosphorus is negligible, and the treated water will still cause environmental problems such as "eutrophication" after being discharged into the water body. Although the three-stage treatment can solve the above problems, it is expensive due to investment and operation costs Difficult to promote on a large scale.

Contents of the invention

The purpose of the present invention is to provide a technical scheme of a sewage treatment method based on a multi-stage vertical flow artificial wetland system in view of the deficiencies in the prior art. Low cost, suitable for large-scale application, the sewage is recycled to make it finally meet the output standard, reducing the occurrence of "eutrophication" pollution and other problems.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

A sewage treatment method based on a multi-stage vertical flow artificial wetland system, characterized in that it comprises the following steps:

1) First, select the location of the multi-level vertical flow constructed wetland system according to the design requirements. The constructed wetland system is set up with 5 compartments, the first compartment is the ascending pool, the second compartment is the descending pool, the third compartment is the ascending pool, and the third compartment is the ascending pool. The fourth grid is the descending pool, the fifth grid is the ascending pool, and a sewage mixing pool is set at the water inlet of the first grid. The sewage mixing pool is filled with inchstones to ensure uniform water distribution in the wetland. There is an upward guide in the wetland. Adjacent compartments are separated by the upper and lower diversion partition walls, the upper and lower pools are equipped with water intakes, and the fifth compartment is equipped with outlets. The water outlet, the water outlet is 10cm away from the ground, and the water outlet is connected to the detection station;

2) Then the sewage is adsorbed to the shunt chamber by the external pump, and is input into the sewage mixing tank through the water inlet pipe. After the sewage is settled in the sewage mixing tank, the sludge and the primary sewage are separated. The filter screen separates the sludge on the upper layer, and passes through The first suction pipe is drawn back to the purification tank for purification, so that the pollutant content in the sludge reaches the standard, and the treated sludge is input into 5 compartments through the second suction pipe;

3) Next, the primary sewage is introduced into the above-mentioned 5 compartments respectively. The 5 compartments are respectively equipped with water quality pollutant concentration detectors and water level gauges. The internal water pollutant concentration detector performs the first detection. At the same time, the primary sewage flows upward into the microbial layer of the grassroots. The microbial layer degrades and transforms the organic matter in the primary sewage, decomposes the pollutants, and the vegetation will precipitate suspended particles. Adsorbed on the root system, it provides a habitat for the growth of microorganisms, and at the same time transports oxygen to the root zone to improve the conduction of water in the soil. After being treated in the upper tank of the first grid, it enters the lower tank of the second grid for purification treatment. The final sewage continues to enter the ascending pool of the third compartment, repeat the process of the ascending pool of the first compartment, and enter the descending pool of the fourth compartment after purification treatment, and finally enter the ascending pool of the fifth compartment for treatment. The water pollutant concentration detector will record a value and feed back the value to the detection station. At the same time, the water level gauge can monitor the water level of each compartment in real time. When the water level in any of the compartments drops, the sewage treatment will automatically stop. At the same time, the pumping The water delivery efficiency of the water pump is improved, so that the sewage continues to flow;

4) When the treated sewage enters the ascending pool of the fifth cell, the aeration device will be automatically opened according to the speed of the water flow, and the air above the soil will pass through the aeration device to form liquid oxygen dissolved in the water, and pass through the above five cells. The treated sewage enters the testing station, and the water that passes the test flows out through the drainage ditch, and the water that does not meet the standard is reflowed into the upward pool of the first cell through the underground pipeline to continue to circulate until it meets the standard and then discharged;

5) The staff regularly cleans the sludge in the purification tank and the sludge in the suction pipe, and checks the pore size of the filter in the sewage mixing tank to ensure that the sludge is filtered.

Furthermore, the length, width, and height of the multi-stage vertical flow constructed wetland system in step 1) are 200cm, 80cm, and 50cm respectively, which not only occupies a small area, but also greatly reduces investment and operation costs.

Further, the lower part of the inner filler in the ascending pool and the descending pool in step 1) is an inchstone with a particle size of 3 to 8 cm, the middle is a volcanic rock with a particle size of 1 cm, the upper part is quartz sand with a particle size of 0.3 to 0.5 cm, and the bottom of the inchstone is An anti-seepage layer is provided, and the anti-seepage layer is a synthetic material partition, and mesh cloth is arranged between the volcanic rock and the inchstone, and between the quartz sand and the volcanic rock, so as to prevent the mixing of fillers in each layer.

Further, the lower diversion partition wall in step 1) is buried 10 cm below the ground surface, and the upper diversion partition wall is 10 cm higher than the surface of the wetland.

Further, the water inlet pipe in step 1) includes a connecting pipe and a horizontal distribution pipe. The horizontal distribution pipe is fixedly connected to the shunt chamber through the connecting pipe. The horizontal distribution pipe is provided with leaking holes with a diameter of 10-15mm. The distance between the leaking holes is from the horizontal distribution The center of the pipe gradually decreases to both sides to ensure uniform water distribution and improve the settlement efficiency of sewage.

Further, the aeration device in step 4) includes a box body, a solar panel and an air intake cover are arranged on the top surface of the box body, the air intake cover is fixedly connected to the box body through an air intake pipe, an air compressor is arranged inside the box body, and the box body The bottom of the body is connected with a fixed pipe, and the fixed pipe is connected with an L-shaped pipe through a telescopic pipe. The L-shaped pipe is evenly equipped with an aeration pipe, and the solar panel can realize its own power supply without external power supply, so as to ensure the long-term operation of the air compressor. In operation, the air enters the aeration device from the air inlet hood and the air inlet pipe, and is pressed into the L-shaped pipe under the action of the air compressor, and aeration is realized under the action of the aeration pipe, and the L-shaped pipe can pass through according to the actual depth of the wetland. The telescopic tube is adjusted to improve the aeration effect of the aeration device.

Further, the air intake cover is provided with a dust-proof net, which can effectively prevent impurities such as leaves from clogging the air intake cover, thereby affecting the normal operation of the aeration device.

Furthermore, a water flow detection device is installed on the side of the L-shaped pipe, through which the upstream tank can be monitored in real time, and when the flow rate of the water is lower than the water flow detection device, the aeration device will automatically start, and the air compressor will be used for aeration The operation increases the water flow rate and increases the oxygen content in the water at the same time.

The present invention has the following beneficial effects due to the adoption of the above technical solution:

1. Compared with the constructed wetland system in the prior art, it can not only degrade and transform the organic matter and harmful substances in the sewage, but also separate the sludge in the sewage, and re-act on the vegetation in the wetland after treatment On, improve the survival rate of vegetation;

2. After cyclic treatment in five compartments, the organic matter and harmful substances in the sewage are effectively reduced, so that the final output water meets the standards. The water quality pollutant concentration detectors in each compartment monitor the corresponding compartments in real time to improve improved the treatment effect of sewage;

3. The aeration device can aerate the treated sewage to increase the dissolved oxygen content in the water and improve the survival rate of plants in the wetland.

The invention has simple structure, remarkable treatment effect on sewage, not only occupies a small area, but also has low operation cost and input cost, and is suitable for large-scale application. The emergence of problems such as nutrient pollution.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing:

Fig. 1 is a structural schematic diagram of a constructed wetland system in a sewage treatment method based on a multi-stage vertical flow constructed wetland system of the present invention;

Fig. 2 is the structural representation of water inlet pipe among the present invention;

Fig. 3 is the structural representation of aeration device among the present invention;

Fig. 4 is the effect figure of COD removal rate of each compartment of wetland among the present invention;

Fig. 5 is the effect diagram of each cell of the wetland to the COD concentration change in the present invention;

Fig. 6 is an effect diagram of the NH ₃ -N removal rate of each cell in the wetland in the present invention;

Fig. 7 is an effect diagram of the change of NH ₃ -N concentration in each cell of the wetland in the present invention;

Fig. 8 is an effect diagram of the removal rate of TN by each cell in the wetland in the present invention;

Fig. 9 is an effect diagram of the change of TN concentration in each cell of the wetland in the present invention;

Fig. 10 is the effect diagram of the removal rate of TP by each cell in the wetland in the present invention;

Fig. 11 is a diagram showing the effect of each cell in the wetland on the change of TP concentration in the present invention.

In the figure: 1-sewage pool; 2-first grid; 3-second grid; 4-third grid; 5-fourth grid; 6-fifth grid; 7-water pump; 8-diversion chamber; 9 -Inlet pipe; 10-filter; 11-purification tank; 12-first suction pipe; 13-second suction pipe; 14-water pollutant concentration detector; 15-water level gauge; 16-aeration device; 17-testing station; 18-underground pipeline; 19-upper diversion partition wall; 20-lower diversion partition wall; 21-connection pipe; 22-horizontal distribution pipe; 23-leakage hole; Compressor; 26-solar panel; 27-intake cover; 28-intake pipe; 29-dust screen; 30-fixed pipe; 31-telescopic pipe; 32-L-shaped pipe; trachea.

detailed description

As shown in Figures 1 to 3, it is a sewage treatment method based on a multi-stage vertical flow constructed wetland system of the present invention, comprising the following steps:

1) First, select the location of the multi-stage vertical flow constructed wetland system according to the design requirements. The length, width, and height of the multi-stage vertical flow constructed wetland system are 200cm, 80cm, and 50cm respectively. Not only does it occupy a small area, but also the input and operating costs Greatly reduced, the constructed wetland system is set to 5 compartments, the first compartment 2 is the ascending pool, the second compartment 3 is the descending pool, the third compartment 4 is the ascending pool, the fourth compartment 5 is the descending pool, and the fifth compartment 6 is the Ascend the pool, and set a sewage allocation pool 1 at the water inlet of the first grid 2. The sewage allocation pool 1 is filled with inchstones to ensure uniform water distribution in the wetland. The wetland is equipped with an upper diversion partition wall 19 and a lower The diversion partition wall 20 is separated by the upper diversion partition wall 19 and the lower diversion partition wall 20 between adjacent compartments, the lower diversion partition wall 20 is buried 10 cm below the ground surface, and the upper diversion partition wall 19 is higher than The surface of the wetland is 10 cm, and the upper pool and the lower pool are equipped with water intakes, and the fifth grid 6 is provided with a water outlet, and the water outlet is 10 cm away from the ground, and the water outlet is connected to the detection station 17. ~8cm inch stone, the middle is volcanic rock with a particle size of 1cm, and the upper part is quartz sand with a particle size of 0.3~0.5cm. The bottom of the inchstone is equipped with an anti-seepage layer, which is a synthetic material partition. Mesh cloth is set between the space, between the quartz sand and the volcanic rock, to prevent the confusion of the fillers in each layer;

The surface area of the wetland in the vertical flow constructed wetland is

A _S ＝[Q(lnC ₀ -lnC _e )]/(K _T Dn)

In the formula: C ₀ - effluent COD (mg/L);

C _e —— COD of entering water (mg/L);

K _T ——reaction rate constant related to temperature (d ^-1 );

Q——the average flow rate of the system (m ³ /d);

D——cell depth (m);

n—cell porosity;

A _S —— system surface area (m ² )

2) Then the sewage is adsorbed to the diversion chamber 8 through the external pump 7, and then input into the sewage pool 1 through the water inlet pipe 9. The water inlet pipe 9 includes a connecting pipe 21 and a horizontal distribution pipe 22, and the horizontal distribution pipe 22 is fixedly connected through the connecting pipe 21 In the diversion chamber 8, the horizontal distribution pipe 22 is provided with leakage holes 23 with a diameter of 10-15mm, and the distance between the leakage holes 23 gradually decreases from the center of the horizontal distribution pipe 22 to both sides, so as to ensure uniform water distribution and improve the settlement of sewage Efficiency, after the sewage is settled in the sewage adjustment tank 1, the sludge and the primary sewage are separated. The filter screen 10 separates the sludge on the upper layer, and is drawn back to the purification tank 11 through the first mud suction pipe 12 for purification, so that the sludge in the sludge The pollutant content of the sludge reaches the standard, and the treated sludge is input into 5 compartments through the second suction pipe 13;

3) Next, the primary sewage is introduced into the above-mentioned 5 compartments, and the 5 compartments are respectively equipped with water quality pollutant concentration detectors 14 and water level gauges 15, and the primary sewage enters the upstream pool of the first compartment 2 through the sewage deployment pool 1 , the water pollutant concentration detector 14 in the first grid 2 performs the first detection, and at the same time, the primary sewage flows upwards into the microbial layer of the grassroots, and the microbial layer degrades and transforms the organic matter in the primary sewage, and decomposes the pollutants , the vegetation will adsorb the sediment suspended particles on the root system, provide a habitat for the growth of microorganisms, and at the same time transport oxygen to the root zone, improve the conduction of water in the soil, and enter the second grid 3 after being treated by the ascending pool of the first grid 2 Purification treatment is carried out in the descending pool of the third grid, and the treated sewage continues to enter the ascending pool of the third grid 4, repeat the process of the ascending pool of the first grid 2, and enter the descending pool of the fourth grid 5 after purification treatment, and finally enter the fifth grid 6 Processing is carried out in the upstream pool, and the water quality pollutant concentration detector 14 will record a value when entering each compartment, and the value will be fed back to the detection station 17. At the same time, the water level gauge 15 can monitor the water level of each compartment in real time. When the water level in one compartment drops, the sewage treatment will automatically stop, and at the same time, the water delivery efficiency of the water pump 7 will be improved, so that the sewage will continue to flow;

The oxygen demand R ₀ of sewage and the oxygen supply P ₀ of plants are respectively

R ₀ =1.5Q(C ₀ -C _e )

P ₀ ＝A _S T ₀ /1000

4) When the treated sewage enters the ascending tank of the fifth grid 6, the aeration device 16 is automatically opened according to the speed of the water flow, and the air above the soil passes through the aeration device to form liquid oxygen dissolved in the water, and after the above five The sewage treated in the cell enters the testing station 17, and the water that passes the test flows out through the drainage ditch, and the water that does not meet the standard passes through the underground pipeline 18 and reflows into the upward pool of the first cell 2 to continue circulating until it meets the standard and then discharged;

The aeration device 16 includes a box body 24, a solar panel 26 and an air intake cover 27 are arranged on the top surface of the box body 24, the air intake cover 27 is fixedly connected to the box body 24 through an air intake pipe 28, and an air compressor is arranged inside the box body 24 25. A fixed pipe 30 is connected to the bottom of the box body 24. The fixed pipe 30 is connected to an L-shaped pipe 32 through a telescopic pipe 31. The L-shaped pipe 32 is evenly provided with an aeration pipe 34. The solar panel 26 can realize its own power supply without Connect the external power supply to ensure the long-term operation of the air compressor 25. The air enters the aeration device 16 from the air intake cover 27 and the air intake pipe 28, and is pressed into the L-shaped pipe 32 under the action of the air compressor 25. The aeration is realized under the action of the tube 34. The L-shaped tube 32 can be adjusted according to the depth of the actual wetland through the telescopic tube 31 to improve the aeration effect of the aeration device 16. The air intake cover 27 is provided with a dust-proof net 29 to prevent The dust net 29 can effectively prevent impurities such as leaves from clogging the intake cover 27, and then affect the normal operation of the aeration device 16. A water flow detection device 33 is arranged on the side of the L-shaped pipe 32, and the upstream pool can be monitored in real time by the water flow detection device 33. Monitoring, when the flow velocity of water is lower than the water flow detection device 33, the aeration device 16 is automatically started, and the aeration operation is performed by the air compressor 25, which improves the water flow velocity and simultaneously increases the oxygen content in the water.

5) The staff regularly cleans the sludge in the purification tank 11 and the sludge in the suction pipe, and checks the aperture of the filter screen 10 in the sewage mixing tank 1 to ensure that the sludge is filtered.

Reeds are planted in the wetland to treat the organic matter in the upstream and downstream ponds. As shown in Figure 4 and Figure 5, the multi-stage vertical flow artificial wetland treatment system has a high removal rate of COD in sewage, and the average COD of the wetland final effluent The removal rate was 92.0%. In May, the removal rate of COD in each cell and the final effluent in the wetland increased significantly compared with April, especially in the first three cells of the wetland. This is because at the initial stage of operation, the microorganisms in the wetland are in the cultivation stage, and the reeds are not yet mature. At this time, the removal of COD is mainly the interception and adsorption of the wetland matrix. After May, a large number of microorganisms were cultivated on the wetland substrate, and the reeds resumed growth, and the removal rate of COD in the wetland increased significantly, indicating that the wetland was successfully activated. The COD removal rate of the multi-stage vertical flow constructed wetland in winter is between 70.7% and 83.1%, and the concentration of COD in the final effluent is 27.83mg/L to 59.81mg/L, while in summer, the average COD removal rate of the wetland is The rate is between 87.3% and 96.1%, and the average concentration of COD in the final effluent is between 7.36mg/L and 22.96mg/L, which can reach the first-class B standard of GB18918-2002 throughout the year, except for December, January and February All of them can meet the first-class A standard of GB18918-2002.

The wetland started in April (as shown in Figure 6 to Figure 9), and the removal rates of NH ₃ -N and TN in sewage in each cell were between 30.1%-78.2% and 29.2%-91.2%, and the effluent NH ₃ - The average concentrations of N and TN are 5.87mg/L and 8.445.87mg/L, respectively, and the average removal rates of NH ₃ -N and TN in the final effluent of the wetland are 85.6% and 88.07%, respectively. At this time, the removal of nitrogen is mainly due to the adsorption of fillers. effect. The nitrogen removal capacity of the wetland system increases with the increase of reeds. At the same time, the types and numbers of microorganisms in the system also gradually increase, and the conditions for the nitrification-denitrification process of biological denitrification are met, that is, the nitrogen content in domestic sewage The organic matter is decomposed through the ammonification process, and the NH ₃ -N produced is converted into nitrite nitrogen under the action of nitrifying bacteria, and then further converted into nitrate nitrogen, and then the nitrate nitrogen is converted into nitrogen gas by the nitrifying bacteria to complete denitrification. The removal rates of NH ₃ -N and TN in winter wetlands are between 53.6%-75.3% and 72.5%-84.9%, respectively, and the average concentrations of NH ₃ -N and TN in the effluent are 5.87mg/L-24.16mg/L and 4.13mg respectively /L～23.13mg/L, from April to September can reach the first-class B standard of GB18918-2002, and can reach the first-class A standard of GB18918-2002 in July and August.

The removal effect of each cell in the wetland on TP in sewage is shown in Figure 10 and Figure 11. In April, the average removal rate of TP in each cell in the wetland was between 17.7% and 90.7%, and the average concentration of TP in the final effluent was After October, the removal rate of TP in the wetland gradually decreased, while the average concentration of TP in the effluent rose from 1.81mg/L to 3.45mg/L. This is because the adsorption of phosphorus by soil and fillers gradually reached saturation. , the adsorption weakens or disappears, and the wetland enters winter, and the reeds wither can no longer absorb phosphorus. The outlet water TP of the multi-stage vertical flow constructed wetland system can reach the first-class B standard of GB18918-2002 from April to September.

To sum up, the water output of the multi-stage vertical flow constructed wetland system can reach the first-level B standard of GB18918-2002 from April to September, and due to the influence of low ambient temperature and wetland plant harvesting from October to March, the water output from the system, nitrogen, and Phosphorus exceeds the first-class B standard of GB18918-2002.

The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications based on the present invention to achieve substantially the same technical effect are covered by the protection scope of the present invention.

Claims (8)

1. A sewage treatment method based on a multi-stage vertical flow artificial wetland system, characterized in that it comprises the steps: 1) First, select the location of the multi-level vertical flow constructed wetland system according to the design requirements. The constructed wetland system is set up with 5 compartments, the first compartment is the ascending pool, the second compartment is the descending pool, the third compartment is the ascending pool, and the third compartment is the ascending pool. The fourth grid is the descending pool, the fifth grid is the ascending pool, and a sewage mixing pool is set at the water inlet of the first grid. The sewage mixing pool is filled with inchstones, and an upper diversion wall and a lower A diversion partition wall, adjacent compartments are separated by the upper diversion partition wall and the lower diversion partition wall, the upper pool and the lower pool are provided with water intakes, the fifth There is a water outlet on the grid, the water outlet is 10cm away from the ground, and the water outlet is connected to the detection station; 2) Then the sewage is adsorbed to the shunt chamber by the external pump, and is input into the sewage mixing pool through the water inlet pipe. After the sewage is settled in the sewage mixing pool, the sludge and the primary sewage are separated, and the filter screen separates the sludge on the upper layer. And it is pumped back to the purification tank through the first suction pipe for purification, so that the pollutant content in the sludge reaches the standard, and the treated sludge is input into 5 compartments through the second suction pipe; 3) Then, the primary sewage is introduced into the above-mentioned 5 compartments respectively, and water quality pollutant concentration detectors and water level gauges are respectively arranged in the 5 compartments. The water quality pollutant concentration detector within one grid conducts the first detection, and at the same time, the primary sewage flows upwards into the microbial layer of the grassroots. The microbial layer degrades and transforms the organic matter in the primary sewage, decomposes the pollutants, and the vegetation will settle. Suspended particles are adsorbed on the root system, and the sewage is treated in the ascending pool of the first compartment and then enters the descending pool of the second compartment for purification treatment, and the treated sewage continues to enter the ascending pool of the third compartment, repeating the process of the ascending pool of the first compartment, After purification treatment, it enters the descending pool of the fourth compartment, and finally enters the ascending pool of the fifth compartment for treatment. When entering each compartment, the water quality pollutant concentration detector will record a value and feed back the value to the detection station. At the same time, the water level The meter can monitor the water level of each compartment in real time. When the water level in any of the compartments drops, the sewage treatment will automatically stop, and at the same time, the water delivery efficiency of the pump will be improved, so that the sewage will continue to flow; 4) When the treated sewage enters the ascending pool of the fifth cell, the aeration device will be automatically opened according to the speed of the water flow, and the air above the soil will pass through the aeration device to form liquid oxygen dissolved in the water, and pass through the above five cells. The treated sewage enters the testing station, and the water that passes the test flows out through the drainage ditch, and the water that does not meet the standard is reflowed into the upward pool of the first cell through the underground pipeline to continue to circulate until it meets the standard and then discharged; 5) The staff regularly cleans the sludge in the purification tank and the sludge in the suction pipe, and checks the pore size of the filter in the sewage mixing tank to ensure that the sludge is filtered. 2. A kind of sewage treatment method based on multi-stage vertical flow constructed wetland system according to claim 1, characterized in that: the length, width and height of the multi-stage vertical flow constructed wetland system in step 1) are respectively 200cm, 80cm, 50cm. 3. A kind of sewage treatment method based on the multi-stage vertical flow constructed wetland system according to claim 1, characterized in that: the lower part of the inner filler in the upward tank and the downward tank in step 1) has a particle size of 3 ~8cm inch stone, the middle is volcanic rock with a particle size of 1cm, and the upper part is quartz sand with a particle size of 0.3~0.5cm. The bottom of the inchstone is provided with an anti-seepage layer, and the anti-seepage layer is a synthetic material partition. Mesh cloth is arranged between the volcanic rock and the inchstone, and between the quartz sand and the volcanic rock. 4. A kind of sewage treatment method based on multi-stage vertical flow constructed wetland system according to claim 1, characterized in that: said lower diversion partition wall in step 1) is buried 10 cm below the surface, and said upper diversion wall The flow partition wall is 10cm higher than the wetland surface. 5. A sewage treatment method based on a multi-stage vertical flow constructed wetland system according to claim 1, characterized in that: the water inlet pipe in step 2) includes a connecting pipe and a horizontal distribution pipe, and the horizontal distribution pipe The connecting pipe is fixedly connected to the distribution chamber, and the horizontal distribution pipe is provided with leakage holes with a diameter of 10-15 mm, and the distance between the leakage holes gradually decreases from the center of the horizontal distribution pipe to both sides. 6. A sewage treatment method based on a multi-stage vertical flow constructed wetland system according to claim 1, characterized in that: the aeration device in step 4) comprises a box, and the top surface of the box is A solar panel and an air intake cover are arranged, and the air intake cover is fixedly connected to the box body through an air intake pipe, an air compressor is arranged inside the box body, and a fixed pipe is connected to the bottom of the box body, and the fixed pipe body L-shaped pipes are connected through telescopic pipes, and aeration pipes are uniformly arranged on the L-shaped pipes. 7. A sewage treatment method based on a multi-stage vertical flow constructed wetland system according to claim 6, characterized in that: a dust-proof net is arranged inside the air inlet cover. 8. A sewage treatment method based on a multi-stage vertical flow constructed wetland system according to claim 6, characterized in that: a water flow detection device is provided on the side of the L-shaped pipe.