阅读说明：本技术 一种防堵塞和强化厌氧氨氧化脱氮的人工湿地系统和技术 (Anti-blocking and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system and technology ) 是由 申彪 张彪 刘垚 杨轲 皮志勇 乔丽丽 于 2020-06-06 设计创作，主要内容包括：本发明公开了一种防堵塞和强化厌氧氨氧化脱氮的人工湿地系统和技术,它涉及水环境治理技术领域。它通过前置塘沉淀可沉降悬浮物,通过纳米气浮滤池去除难沉降的悬浮物,通过仿生水草-植物湿地去除水体中悬浮物,并结合投加微生物去除水体中的SS、COD、氨氮、总磷和总氮,然后通过潜流湿地去除水体中的COD、氨氮、总磷和总氮,同时控制潜流湿地水位进行高水位-低水位-高水位周期性运行,扩大水陆交错区,强化人工湿地厌氧氨氧化脱氮,最后受污染水体经过表流湿再次进行脱氮、除磷,实现整个系统进水悬含量逐渐削减,强化人工湿地脱氮除磷效果的目的,本发明显著提高出水水质,防止人工湿地堵塞,延长人工湿地运行寿命,应用前景广阔。(The invention discloses an anti-clogging and anaerobic ammonia oxidation denitrification enhancing constructed wetland system and technology, and relates to the technical field of water environment treatment. The invention deposits settleable suspended matters through a preposed pond, removes suspended matters difficult to settle through a nano air flotation filter tank, removes suspended matters in a water body through a bionic aquatic plant-plant wetland, removes SS, COD, ammonia nitrogen, total phosphorus and total nitrogen in the water body by combining with the addition of microorganisms, then removes the COD, the ammonia nitrogen, the total phosphorus and the total nitrogen in the water body through an underflow wetland, controls the water level of the underflow wetland to periodically operate at a high water level, a low water level and a high water level, enlarges an amphibious staggered area, strengthens the anaerobic ammonia oxidation denitrification of the artificial wetland, and finally carries out denitrification and dephosphorization again through surface flow moisture, thereby realizing the purposes of gradually reducing the inflow suspended content of the whole system and strengthening the denitrification and dephosphorization effects of the artificial wetland.)

1. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system is characterized by comprising a water inlet system (1), a pretreatment system and an constructed wetland system, wherein the water inlet system (1), the pretreatment system and the constructed wetland system are sequentially connected; the water inlet system (1) comprises a filter grid (1-1), a water inlet lift pump (1-2), a water inlet valve (1-3) and a first flowmeter (1-4), the pretreatment system comprises a pre-pond system (2) and a nano air-flotation filter pond system (4), the artificial wetland system comprises a microbial agent dosing system (6), a bionic aquatic plant-plant wetland system (7), a horizontal subsurface flow artificial wetland system (9), a subsurface flow wetland PLC (programmable logic controller) water level automatic control system (10), a vertical subsurface flow artificial wetland system (11) and a surface flow artificial wetland system (12), the filter grid (1-1) is placed in a polluted water body, an outlet of the water inlet lift pump (1-2) is connected with a water inlet of the pre-pond system (2) to pump the polluted water body into the pretreatment system, a water inlet valve (1-3) and a first flow meter (1-4) are arranged on a pipeline connected with a water inlet lift pump (1-2) and a preposed pond system (2), the water inlet flow is controlled through the water inlet valve (1-3) and the first flow meter (1-4), the preposed pond system (2) is communicated with a nano air-flotation filter system (4), a first control valve (3) is arranged in the middle, the preposed pond system (2) is used for precipitating settleable suspended matters in a water body, the nano air-flotation filter system (4) is used for separating difficultly-settled suspended matters in the water body and aerating the polluted water body to improve dissolved oxygen in the water body, the nano air-flotation filter system (4) is communicated with a bionic aquatic weed-plant wetland system (7), a second control valve (5) is arranged between the bionic aquatic weed-plant system and the microbial agent feeding system (6), the microbial agent is pumped into a bionic aquatic weed-plant wetland system (7) by a microbial agent dosing system (6), the water outlet of the bionic aquatic weed-plant wetland system (7) is connected with the water inlet of the horizontal subsurface flow constructed wetland system (9) through a pipeline, the pipeline is provided with a third control valve (8), the water outlet of the horizontal subsurface flow constructed wetland system (9) is connected with the water inlet of the vertical subsurface flow constructed wetland system (11), the water outlet of the vertical subsurface flow constructed wetland system (11) is connected with the water inlet of the surface flow constructed wetland system (12), the horizontal subsurface flow constructed wetland system (9) and the vertical subsurface flow constructed wetland system (11) are both provided with water outlets with different heights, is connected with the PLC water level automatic control system (10) of the subsurface flow wetland in a control way, and the water body is discharged outside after passing through the surface flow artificial wetland system (12).

2. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system according to claim 1, characterized in that the pre-pond system (2) consists of a pre-pond (2-1), and a water lifting aeration device (2-3) and a push flow aeration device (2-4) which are arranged at the rear section of the pre-pond (2-1), wherein the water lifting aeration device (2-3) and the push flow aeration device (2-4) are both connected with an aeration device PLC control cabinet (2-2), the pre-pond (2-1) is used for precipitating suspended matters which can be precipitated in a water body, and the water lifting aeration device (2-3) and the push flow aeration device (2-4) are used for forming a fountain landscape and simultaneously improving the dissolved oxygen and the fluidity of the water body;

the water lifting aeration system consisting of the water lifting aeration device (2-3) and the PLC automatic timing control system of the aeration device PLC control cabinet (2-2) can automatically lift water and aerate at regular time to form a fountain landscape, enhance the dissolved oxygen of the water body, strengthen the effect of aerobic microorganisms of the water body and have certain removal effect on COD and ammonia nitrogen;

the plug-flow aeration device (2-4) is arranged at the rear section of the front pond (2-1), can effectively enhance the water fluidity of the front pond and increase the dissolved oxygen content of the water body while not interfering the sedimentation of the settleable suspended matters, avoids the polluted water body from causing a large amount of growth of algae due to the limitation of the structure of the front pond and even generating a black and odorous phenomenon, and effectively improves the micro-ecological environment of the water body.

3. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system according to claim 1, characterized in that the nano air flotation filter system (4) comprises an air flotation tank and a nano aeration device, the polluted water enters the air flotation filter to remove suspended matters which are difficult to settle in the water, the concentration of the suspended matters in the water is further reduced, the nano aeration device improves the dissolved oxygen in the water in a short time, the dissolved oxygen level of the inlet water of the constructed wetland system is ensured, and the removal of ammonia nitrogen and COD pollutants by nitrifying bacteria is enhanced; the air floatation tank consists of a nano aeration tank (4-1), a solid-liquid separation tank (4-2), a clean water tank (4-3) and a scum collection tank (4-7), a nano aeration device consists of a water replenishing pump (4-4), an aeration head assembly (4-5) and a host (4-6), the water replenishing pump (4-4) and the aeration head assembly (4-5) are arranged in the nano aeration tank (4-1), the water replenishing pump (4-4) and the aeration head assembly (4-5) are connected to the host (4-6), a polluted water body enters the nano aeration tank (4-1) from a front pond to be fully mixed with steam and water, then enters the solid-liquid separation tank (4-2) to be subjected to solid-liquid separation, and suspended matters are positioned on the upper layer after being combined with nano bubbles, the floating slag enters a floating slag collecting pool (4-7), clear water with suspended matters removed enters a clear water pool (4-3) outside a discharge system, and then enters an artificial wetland system.

4. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system according to claim 1, characterized in that the microbial agent dosing system (6) comprises a ton barrel (6-1), a stirrer (6-2), a dosing valve (6-3), a dosing pump (6-4) and a second flowmeter (6-5), wherein the stirrer (6-2) is installed in the ton barrel (6-1), the outlet of the ton barrel (6-1) is connected to the bionic aquatic weed-plant wetland system (7) through the dosing pump (6-4), the dosing valve (6-3) is installed at the outlet of the ton barrel (6-1), the second flowmeter (6-5) is installed on a pipeline connecting the dosing pump (6-4) and the bionic aquatic weed-plant wetland system (7), the microbial agent dosing system (6) adds the screened microbial agent to the constructed wetland system in the starting period of the constructed wetland, so that the speed of film formation of the bionic aquatic weeds and plant roots in the bionic aquatic weeds-plant wetland can be increased, the construction of the subsurface flow wetland microbial system is accelerated, and the water quality purification effect of the constructed wetland is enhanced.

5. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system according to claim 1, characterized in that the bionic aquatic weed-plant wetland system (7) comprises a bionic aquatic weed-plant wetland (7-1) and a bionic aquatic weed-plant floating island, the bionic aquatic weed-plant floating island comprises aquatic plants (7-2), floating bodies (7-3) and bionic aquatic weeds (7-4), the polluted water body passes through the bionic aquatic weed-plant wetland system (7), the aquatic plants (7-2) and the bionic aquatic weeds (7-4) adsorb residual suspended matters in the water body, and microbial films are gradually formed on the surfaces of the polluted water body, COD, ammonia nitrogen, SS, total nitrogen and total phosphorus pollutants in the water body are removed, and the concentration of the suspended matters in the inlet water of the constructed wetland is reduced.

6. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system according to claim 1, characterized in that the horizontal subsurface flow constructed wetland system (9) is composed of horizontal subsurface flow constructed wetland aquatic plants (9-1) and horizontal subsurface flow constructed wetland substrates (9-2), the horizontal subsurface flow constructed wetland aquatic plants (9-1) are aquatic plant communities composed of various aquatic plants according to growth characteristics and functions, the horizontal subsurface flow constructed wetland substrates (9-2) are growth substrates of the horizontal subsurface flow constructed wetland aquatic plants (9-1) composed of various functional fillers according to constructed wetland design standards, and the water distribution of the horizontal subsurface flow constructed wetland system (9) is in the horizontal direction;

the vertical subsurface flow constructed wetland system (11) is composed of vertical subsurface flow constructed wetland aquatic plants (11-1) and a vertical subsurface flow constructed wetland substrate (11-2), the vertical subsurface flow constructed wetland aquatic plants (11-1) are aquatic plant communities formed by various aquatic plants according to growth characteristics and functions of the aquatic plants, the vertical subsurface flow constructed wetland substrate (11-2) is a growth substrate of the vertical subsurface flow constructed wetland aquatic plants (11-1) formed by various functional fillers according to constructed wetland design standards, and the water distribution of the vertical subsurface flow constructed wetland system (11) is in a vertical direction.

7. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system according to claim 1, characterized in that the PLC water level automatic control system (10) of the subsurface flow wetland consists of a PLC main control cabinet (10-1), a first electromagnetic valve (10-2), a second electromagnetic valve (10-3), a third electromagnetic valve (10-4) and a fourth electromagnetic valve (10-5), wherein the first electromagnetic valve (10-2), the second electromagnetic valve (10-3), the third electromagnetic valve (10-4) and the fourth electromagnetic valve (10-5) are all connected to the PLC main control cabinet (10-1); the horizontal subsurface flow constructed wetland system (9) is provided with water outlets with different heights, and a first electromagnetic valve (10-2) and a second electromagnetic valve (10-3) which are controlled by a PLC main control cabinet (10-1) are arranged on the water outlets; the vertical subsurface flow constructed wetland system (11) is provided with water outlets with different heights, a third electromagnetic valve (10-4) and a fourth electromagnetic valve (10-5) which are controlled by a PLC main control cabinet (10-1) are arranged on the water outlets, and the horizontal subsurface flow constructed wetland system (9) and the vertical subsurface flow constructed wetland system (11) are controlled by the subsurface flow PLC water level automatic control system (10) to alternately operate according to the periodicity of high water level, low water level and high water level, so that a land and water staggered zone with a fixed period is formed.

8. The anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system according to claim 1, characterized in that the surface flow constructed wetland system (12) comprises surface flow constructed wetland aquatic plants (12-1), the surface flow constructed wetland aquatic plants (12-1) are aquatic plant communities formed by a plurality of aquatic plants according to growth characteristics and functions thereof, the polluted water body enters the surface flow constructed wetland system (12) through the vertical subsurface flow constructed wetland system (11), and is subjected to interception and absorption by the surface flow constructed wetland aquatic plants (12-1), microbial degradation and removal of pollutants in the water body.

9. An anti-clogging and anaerobic ammonia oxidation denitrification enhancing constructed wetland method is characterized by comprising the following steps:

(1) impurities and larger suspended matters in the polluted water body are removed through a filtering grid (1-1), then enters a pretreatment system consisting of a preposed pond system (2) and a nano air-flotation filter system (4), firstly removes settleable suspended matters and COD in the polluted water body through the sedimentation of the preposed pond (2-1), and the rear end in the front pond is provided with a water lifting aeration system and a plug flow aeration system for increasing oxygen and improving water body fluidity, so that the water quality deterioration caused by low dissolved oxygen content or poor fluidity of the water body of the front pond is avoided, then the polluted water body enters a nano aeration filter tank after passing through a preposed pond, suspended matters which are difficult to remove through sedimentation in the water body are removed through the nano air flotation filter tank, the concentration of the suspended matters in the water body is further reduced, meanwhile, the polluted water body is aerated, and the dissolved oxygen level of the inlet water of the artificial wetland system is improved;

(2) the polluted water enters the artificial wetland system after passing through the pretreatment system, firstly, the plant root system of the bionic aquatic weed-plant wetland system (7) and the bionic aquatic weed in the water further adsorb the residual suspension in the water, the soluble organic matters in the water are removed, microorganisms are added by combining the microbial agent adding system (6), a microbial film is formed on the surfaces of the plant root system and the bionic aquatic weed, SS, COD, ammonia nitrogen, total phosphorus and total nitrogen in the water are removed, and the ammonia nitrogen is converted into nitrate nitrogen or nitrite nitrogen to provide a substrate for anaerobic ammonia oxidation of the subsurface wetland; then the sewage enters a multi-stage subsurface flow wetland consisting of a horizontal subsurface flow constructed wetland system (9) and a vertical subsurface flow constructed wetland system (11), and SS, COD, ammonia nitrogen, total phosphorus and total nitrogen pollutants in a water body are removed through the processes of sedimentation, filtration, adsorption, microbial degradation and plant absorption; finally, the polluted water-free body enters a surface flow artificial wetland system (12) to further remove nitrogen and phosphorus pollutants in the water body for discharge;

(3) in the operation process of the artificial wetland system, the water level of the subsurface flow artificial wetland ecosystem is periodically regulated through the subsurface flow wetland PLC water level automatic control system (10), so that the water level of the artificial wetland ecosystem is kept in a high-water-level-low-water-level-high-water-level operation mode, a controllable periodic land and water staggered belt is formed, the abundance of anaerobic ammonia oxidizing bacteria can be effectively improved through the periodic land and water staggered belt, the denitrification efficiency of the anaerobic ammonia oxidizing bacteria is further enhanced, the denitrification capability of the artificial wetland is enhanced, ammonia nitrogen, nitrate nitrogen and total nitrogen in a water body are removed, the thorough denitrification of the polluted water body is realized, and the water quality is purified.

10. The anti-clogging and enhanced anaerobic ammonia oxidation and denitrification constructed wetland method according to claim 9, characterized in that the pretreatment system in step (1) adopts a mode of precipitating settleable suspended matters in the water body at the front section of the pre-pond, and adopts a mode of water lifting aeration and plug flow aeration at the rear section of the pre-pond to enhance the dissolved oxygen and the fluidity of the water body, so as to avoid the water quality deterioration of the water body of the pre-pond and cause secondary pollution; the nano air-flotation filter tank is adopted to remove suspended matters which are difficult to settle in the water body, the concentration of the suspended matters in the water body is further reduced, the level of dissolved oxygen of the inlet water of the bionic aquatic plant-plant wetland in the polluted water body can be effectively improved after passing through the nano air-flotation filter tank, an aeration system does not need to be arranged on the bionic aquatic plant-plant wetland system, the construction and operation cost is saved, and the treatment effect is improved;

in the step (2), the bionic aquatic weed-plant wetland is adopted to further adsorb suspended matters in the water body, the concentration of the suspended matters in the inflow water of the subsurface flow wetland is reduced, and ammonia nitrogen, COD, total phosphorus and total nitrogen in the water body are removed through a microbial film formed by a plant root system and the bionic aquatic weed; removing pollutants in the water body and purifying the water by adopting a mode of connecting a bionic aquatic plant-plant wetland → a horizontal subsurface flow wetland → a vertical subsurface flow wetland → a multi-stage artificial wetland of a surface flow wetland in series;

and (3) forming a controllable periodic land and water staggered belt for the artificial wetland ecosystem by the PLC water level automatic control system, wherein the land and water staggered belt is a 'hot zone' for anaerobic ammonia oxidation and denitrification, and the controllable periodic land and water staggered belt can effectively improve the abundance of anaerobic ammonia oxidation bacteria, strengthen the anaerobic ammonia oxidation and denitrification process and realize efficient denitrification.

Technical Field

The invention relates to the technical field of water environment treatment, in particular to an anti-clogging and anaerobic ammonia oxidation denitrification enhanced constructed wetland system and technology.

Background

Along with the rapid development of economy in China, urban construction is accelerated continuously, the urban water environment is destroyed due to the disordered discharge of water, and the ecological water environment in China is further deteriorated due to the imperfect matched sewage treatment facility, so that the water pollution is increasingly serious, wherein the water environment problems such as water eutrophication, black and odorous water seriously affect the urban image and the living level of surrounding residents, and the construction of an ecological civilization-type society in which people and nature are harmonious in China is restricted. As an environment-friendly technology, the constructed wetland has the advantages of low operating cost, simplicity in maintenance, load impact resistance and the like, and has important significance for water environment treatment and ecological civilized construction in China, but because the popularization of the constructed wetland is restricted by some defects of the constructed wetland, such as constructed wetland blockage, poor denitrification effect and the like, the design of an artificial wetland system and technology for preventing blockage and strengthening anammox denitrification is particularly necessary.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an anti-clogging and anaerobic ammonia oxidation denitrification enhancing constructed wetland system and technology, which can prolong the operation time of the constructed wetland, enhance the denitrification effect of the constructed wetland, have good denitrification and dephosphorization effects, reduce the operation load and the clogging risk of the constructed wetland, facilitate the popularization and application of the constructed wetland technology, accelerate the recovery of the water environment and the water ecosystem, promote the construction of an ecological civilized society in which people and nature are harmonious in China, and are easy to popularize and use.

In order to achieve the purpose, the invention is realized by the following technical scheme: an anti-clogging and anaerobic ammonia oxidation and denitrification enhancing constructed wetland system comprises a water inlet system, a pretreatment system and an constructed wetland system, wherein the water inlet system, the pretreatment system and the constructed wetland system are sequentially connected; the water inlet system comprises a filter grid, a water inlet lift pump, a water inlet valve and a first flow meter, the pretreatment system comprises a pre-pond system and a nano air-flotation filter system, the artificial wetland system comprises a microbial agent dosing system, a bionic aquatic weed-plant wetland system, a horizontal subsurface flow artificial wetland system, a subsurface flow wetland PLC water level automatic control system, a vertical subsurface flow artificial wetland system and a surface flow artificial wetland system, the filter grid is placed in a polluted water body, the outlet of the water inlet lift pump is connected with the water inlet of the pre-pond system, the water body is pumped into the pretreatment system, the water inlet lift pump is provided with the water inlet valve and the first flow meter on a pipeline connected with the pre-pond system, the water inlet flow is controlled by the water inlet valve and the first flow meter, the pre-pond system is communicated with the nano air-flotation filter system, the middle of the pre-pond system is provided with the first control valve, the pre-pond system is used for precipitating settleable suspended matters in a water body, the nano air-flotation filter system is used for separating difficultly-settled suspended matters in the water body and aerating the polluted water body to improve the dissolved oxygen of the water body, the nano air-flotation filter system is communicated with the bionic aquatic weed-plant wetland system, a second control valve is arranged between the nano air-flotation filter system and the bionic aquatic weed-plant wetland system, the bionic aquatic weed-plant wetland system is communicated with a dosing port of a microbial agent dosing system, a microbial agent is pumped into the bionic aquatic weed-plant wetland system by the microbial agent dosing system, a water outlet of the bionic aquatic weed-plant wetland system is connected with a water inlet of the horizontal subsurface flow artificial wetland system through a pipeline, a third control valve is arranged on the pipeline, a water outlet of the horizontal subsurface flow artificial wetland system is connected with a water inlet of the vertical subsurface flow artificial wetland system, and a water outlet of the vertical subsurface flow artificial wetland system is connected with a water inlet of the surface flow artificial wetland system, the horizontal subsurface flow constructed wetland system and the vertical subsurface flow constructed wetland system are respectively provided with water outlets with different heights, and are connected with the PLC water level automatic control system of the subsurface flow wetland in a control way, and water is discharged after passing through the surface flow constructed wetland system.

Preferably, the preposed pond system consists of a preposed pond, and a water lifting aeration device and a push flow aeration device which are arranged at the rear section of the preposed pond, wherein the water lifting aeration device and the push flow aeration device are both connected with a PLC control cabinet of the aeration device, the preposed pond is used for precipitating suspended matters capable of settling in a water body, and the water lifting aeration device and the push flow aeration device are used for forming a fountain landscape and simultaneously improving the dissolved oxygen and the mobility of the water body. The water lifting aeration system consisting of the water lifting aeration device and the PLC automatic timing control system of the PLC control cabinet of the aeration device can automatically lift water and aerate water at regular time to form a fountain landscape, enhance the dissolved oxygen of the water body, strengthen the effect of aerobic microorganisms of the water body and have certain removal effect on COD and ammonia nitrogen; the plug-flow aeration device is arranged at the rear section of the front pond, can effectively enhance the water body fluidity of the front pond while not interfering the sedimentation of suspended matters, increases the dissolved oxygen content of the water body, avoids the phenomenon that a large amount of algae grows and even generates black and odorous substances due to the limitation of the structure of the front pond in the polluted water body, and effectively improves the micro-ecological environment of the water body.

Preferably, the nano air-flotation filter tank system comprises an air-flotation tank and a nano aeration device, a polluted water body enters the air-flotation filter tank to remove suspended matters which are difficult to settle in the water body, the concentration of the suspended matters in the water body is further reduced, the dissolved oxygen of the water body is improved by the nano aeration device in a short time, the dissolved oxygen level of inlet water of the artificial wetland system is ensured, the removal effect of aerobic bacteria such as nitrobacteria on pollutants such as ammonia nitrogen, COD (chemical oxygen demand) and the like is enhanced, so that the bionic aquatic plant-plant wetland is not required to be provided with the aeration device, and the investment is reduced; the air supporting pond is by nanometer aeration tank, the solid-liquid separation pond, clean water basin and dross collecting pit constitute, nanometer aeration equipment is by the moisturizing pump, aeration head subassembly and host computer are constituteed, install the moisturizing pump in the nanometer aeration tank, the aeration head subassembly, the moisturizing pump, the aeration head subassembly all is connected to the host computer, receive the contaminated water body and get into at first entering nanometer aeration tank and carry out abundant steam-water mixture after getting into nanometer air supporting system from leading pond, then get into the solid-liquid separation pond and carry out solid-liquid separation, be in the upper strata behind the suspended solid combination nanometer bubble, get into the dross collecting pit, get rid of outside the system, the clear water that gets rid of the suspended solid gets into the clean water basin, get into constructed wetland system afterwards.

Preferably, the microbial agent dosing system comprises a ton barrel, a stirrer, a dosing valve, a dosing pump and a second flowmeter, wherein the stirrer is installed in the ton barrel, an outlet of the ton barrel is connected to the bionic aquatic weed-plant wetland system through the dosing pump, the dosing valve is installed at the outlet of the ton barrel, the second flowmeter is installed on a pipeline, connected with the bionic aquatic weed-plant wetland system, of the dosing pump, and the dosing amount is controlled through the dosing valve and the second flowmeter; the microbial agent dosing system adds the screened microbial agent to the artificial wetland system in the starting period of the artificial wetland, so that the speed of film formation of the bionic aquatic weeds and the plant roots in the bionic aquatic weeds-plant wetland can be increased, the construction of the subsurface flow wetland microbial system is accelerated, and the water quality purification effect of the artificial wetland is enhanced.

Preferably, the bionic aquatic plant-plant wetland system comprises a bionic aquatic plant-plant wetland and a bionic aquatic plant-plant floating island, wherein the bionic aquatic plant-plant floating island comprises aquatic plants, floating bodies and bionic aquatic plants, the polluted water body passes through the bionic aquatic plant-plant wetland system, the aquatic plants and the bionic aquatic plants adsorb residual suspended matters in the water body, a microbial film is gradually formed on the surface of the polluted water body, COD, ammonia nitrogen, SS, total nitrogen and total phosphorus pollutants in the water body are removed, and the concentration of the suspended matters in the inlet water of the artificial wetland is reduced.

Preferably, the horizontal subsurface flow constructed wetland system consists of horizontal subsurface flow constructed wetland aquatic plants and a horizontal subsurface flow constructed wetland matrix, the horizontal subsurface flow constructed wetland aquatic plants are aquatic plant communities formed by various aquatic plants according to growth characteristics and functions, the horizontal subsurface flow constructed wetland matrix is a growth matrix of the horizontal subsurface flow constructed wetland aquatic plants formed by various functional fillers according to constructed wetland design standards, and the water distribution of the horizontal subsurface flow constructed wetland system is in the horizontal direction.

Preferably, the vertical subsurface flow constructed wetland system consists of vertical subsurface flow constructed wetland aquatic plants and a vertical subsurface flow constructed wetland substrate, the vertical subsurface flow constructed wetland aquatic plants are aquatic plant communities formed by various aquatic plants according to the growth characteristics and the functions of the aquatic plants, the vertical subsurface flow constructed wetland substrate is a growth substrate of the vertical subsurface flow constructed wetland aquatic plants formed by various functional fillers according to the constructed wetland design standard, and the water distribution of the vertical subsurface flow constructed wetland system is in the vertical direction.

Preferably, the PLC water level automatic control system for the subsurface flow wetland consists of a PLC main control cabinet, a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve and a fourth electromagnetic valve, wherein the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve are all connected to the PLC main control cabinet; the subsurface flow wetland comprises a horizontal subsurface flow wetland and a vertical subsurface flow wetland, and is provided with water outlets with different heights, and the water outlets are provided with electromagnetic valves controlled by a PLC automatic control system, specifically: the horizontal subsurface flow constructed wetland system is provided with water outlets with different heights, and a first electromagnetic valve and a second electromagnetic valve which are controlled by a PLC main control cabinet are arranged on the water outlets; the vertical subsurface flow constructed wetland system is provided with water outlets with different heights, and a third electromagnetic valve and a fourth electromagnetic valve which are controlled by a PLC main control cabinet are arranged on the water outlets; the water outlets with different heights are opened at regular time by the PLC water level automatic control system of the subsurface flow wetland, so that the water levels of the horizontal subsurface flow artificial wetland system and the vertical subsurface flow artificial wetland system alternately operate according to the periodicity of high water level-low water level-high water level, water and land staggered zones with fixed periods are formed, anaerobic ammonia oxidation bacteria 'hot zones' are enlarged, the anaerobic ammonia oxidation denitrification process of the subsurface flow artificial wetland is strengthened, the denitrification effect of the artificial wetland is strengthened, ammonia nitrogen adsorbed in the filler is released, the service life of the artificial wetland filler is prolonged, and the service life of the artificial wetland is prolonged.

Preferably, the subsurface flow wetland is not limited to the type or combination of the subsurface flow wetland, the subsurface flow wetland is not limited to the type, function and combination of the filler, the aquatic plants planted in the subsurface flow wetland are not limited to the type and reasonable density of the aquatic plants capable of normally growing under proper climatic conditions, and the main functions of the plants are to absorb nutrient elements such as nitrogen and phosphorus in water, purify water, dredge wetland pores and prevent blockage.

Preferably, the surface flow artificial wetland system comprises surface flow artificial wetland aquatic plants, the surface flow artificial wetland aquatic plants are aquatic plant communities formed by a plurality of aquatic plants according to growth characteristics and functions of the aquatic plants, the polluted water body enters the surface flow artificial wetland system through the vertical subsurface flow artificial wetland system, and the pollutants in the water body are removed through interception and absorption of the surface flow artificial wetland aquatic plants and degradation of microorganisms.

An anti-clogging and anaerobic ammonia oxidation denitrification enhancing constructed wetland technology comprises the following steps:

(1) impurities and larger suspended matters in the polluted water body are removed through a filter grid, then the polluted water body enters a pretreatment system consisting of a preposed pond system and a nano air-flotation filter system, firstly, settleable suspended matters and COD in the polluted water body are settled through the preposed pond, then suspended matters which are difficult to settle in the water body are removed through the nano air-flotation filter, the concentration of the suspended matters in the water body is further reduced, and meanwhile, aeration is carried out on the polluted water body, so that the dissolved oxygen level of the water body is improved;

(2) the method comprises the steps that polluted water enters an artificial wetland system after passing through a pretreatment system, firstly, residual suspension in the water is further adsorbed by a plant root system of a bionic aquatic weed-plant wetland system and bionic aquatic weeds in the water, and microorganisms are added by combining a microbial agent dosing system to form a microbial film, SS, COD, ammonia nitrogen, total phosphorus and total nitrogen in the water are removed, and meanwhile, the ammonia nitrogen is converted into nitrate nitrogen or nitrite nitrogen to provide a substrate for anaerobic ammonia oxidation of the subsurface wetland; then entering a multi-stage subsurface flow wetland consisting of a horizontal subsurface flow constructed wetland system and a vertical subsurface flow constructed wetland system, and removing pollutants such as SS, COD, ammonia nitrogen, total phosphorus, total nitrogen and the like in the water body through the processes of sedimentation, filtration, adsorption, microbial degradation, plant absorption and the like; finally, the polluted water-free body enters a surface flow constructed wetland system, and pollutants such as nitrogen, phosphorus and the like in the water body are further removed and discharged;

(3) in the operation process of the artificial wetland system, the water level of the subsurface flow artificial wetland ecosystem is periodically adjusted through the subsurface flow wetland PLC water level automatic control system, so that the water level of the artificial wetland ecosystem is kept in a high-water-level-low-water-level-high-water-level operation mode, a controllable periodic land and water staggered belt is formed, the abundance of anaerobic ammonia oxidizing bacteria can be effectively improved through the periodic land and water staggered belt, the denitrification efficiency of the anaerobic ammonia oxidizing bacteria is further enhanced, the denitrification capability of the artificial wetland is enhanced, ammonia nitrogen, nitrate nitrogen and total nitrogen in a water body are removed, the thorough denitrification of the polluted water body is realized, and the water quality is purified.

Preferably, the pretreatment system in the step (1) adopts the mode of precipitating settleable suspended matters in the water body at the front section of the preposed pond, and adopts the modes of water lifting aeration and plug flow aeration at the rear section of the preposed pond to enhance the dissolved oxygen and the mobility of the water body, so that the water quality deterioration of the preposed pond is avoided, and secondary pollution is caused; the nano air-flotation filter tank is adopted to remove suspended matters which are difficult to settle in the water body, the concentration of the suspended matters in the water body is further reduced, the level of dissolved oxygen in the water entering the bionic aquatic plant-plant wetland can be effectively improved when the polluted water body passes through the nano air-flotation filter tank, an aeration system does not need to be arranged on the bionic aquatic plant-plant wetland system, the construction and operation cost is saved, and the treatment effect is improved.

Preferably, the bionic aquatic weed-plant wetland is adopted in the step (2) to further adsorb suspended matters in the water body, the concentration of the suspended matters in the inflow water of the subsurface flow wetland is reduced, and ammonia nitrogen, COD, total phosphorus and total nitrogen in the water body are removed through a microbial film formed by a plant root system and the bionic aquatic weed; the water quality is purified by removing pollutants in the water body by adopting a mode of connecting the multi-stage artificial wetland of the bionic aquatic weed-plant wetland → the horizontal subsurface flow wetland → the vertical subsurface flow wetland → the surface flow wetland in series.

Preferably, in the step (3), the artificial wetland ecosystem is formed into a controllable periodic land-water interlaced belt through a PLC water level automatic control system, the land-water interlaced belt is a 'hot zone' of anammox denitrification, and the controllable periodic land-water interlaced belt can effectively improve the abundance of anammox bacteria, strengthen the anammox denitrification process and realize efficient denitrification.

The invention has the beneficial effects that: the system and the technology adopt the preposed pond, the nano air-flotation filter tank, the bionic aquatic plants and the plant root system, and gradually remove suspended matters in the water body through measures such as precipitation, air-flotation separation, adsorption and the like, reduce the concentration of the suspended matters entering the subsurface flow wetland, reduce the blocking risk of the artificial wetland and prolong the service life of the artificial wetland; can expand constructed wetland water and land staggered belt through forming controllable water and land staggered belt, strengthen anaerobic ammonia oxidation "hot area", realize the thorough denitrogenation of contaminated water body, improve nitrogen phosphorus in sewage treatment and get rid of the effect, get rid of pollutants such as COD, ammonia nitrogen, total nitrogen and total phosphorus in the water, purify water quality, improve water ecological environment, anaerobic ammonia oxidizing bacteria can effectively release constructed wetland filler and adsorb ammonia nitrogen in addition, extension constructed wetland filler change time, improve constructed wetland operating life.

Drawings

The invention is described in detail below with reference to the drawings and the detailed description;

FIG. 1 is a plan view of the system of the present invention;

FIG. 2 is a process flow diagram of the present invention;

FIG. 3 is a schematic structural diagram of a bionic aquatic weed-plant floating island in the bionic aquatic weed-plant wetland system of the present invention;

FIG. 4 is a schematic structural diagram of an air flotation tank in the nano air flotation filter system of the invention.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

Referring to fig. 1 to 4, the following technical solutions are adopted in the present embodiment: the system comprises a water inlet system 1, a pretreatment system and an artificial wetland system, wherein the water inlet system 1, the pretreatment system and the artificial wetland system are sequentially connected; the water inlet system 1 comprises a filter grid 1-1, a water inlet lift pump 1-2, a water inlet valve 1-3 and a first flow meter 1-4, the pretreatment system comprises a pre-pond system 2 and a nano air-flotation filter tank system 4, and the artificial wetland system comprises a microbial agent dosing system 6, a bionic aquatic plant-plant wetland system 7, a horizontal subsurface flow artificial wetland system 9, a subsurface flow wetland PLC water level automatic control system 10, a vertical subsurface flow artificial wetland system 11 and a surface flow artificial wetland system 12.

The filter grid 1-1 is placed in the polluted water body, the outlet of the intake lift pump 1-2 is connected with the water inlet of the preposed pond system 2, the polluted water body is pumped into the pretreatment system, the pipeline connecting the intake lift pump 1-2 with the preposed pond system 2 is provided with an intake valve 1-3 and a first flow meter 1-4, the water outlet of the preposed pond system 2 is communicated with the water inlet of the nano air-flotation filter system 4 through a pipeline, the pipeline is provided with a first control valve 3, the preposed pond system 2 is used for precipitating settleable suspended matters in the water body, the nano air-flotation filter system 4 is used for separating difficultly-settleable suspended matters in the water body, and aerating the polluted water body to improve the dissolved oxygen in the water body, wherein a water outlet of the nano air flotation filter tank system 4 is communicated with a bionic aquatic plant-plant wetland system 7, and a second control valve 5 is arranged between the nano air flotation filter tank system and the bionic aquatic plant-plant wetland system. After passing through the pretreatment system, the polluted water body firstly passes through the bionic aquatic weed-plant wetland system 7, the bionic aquatic weed-plant wetland system 7 is communicated with a dosing port of the microbial agent dosing system 6, when the system is started in the initial stage or the water outlet effect is reduced, the microbial agent dosing system 6 feeds the microbial agent into the bionic aquatic weed-plant wetland system 7, the microbial agent is pumped into the bionic aquatic weed-plant wetland system 7 by the microbial agent dosing system 6, the polluted water body passes through the bionic aquatic weed-plant wetland and then enters the horizontal subsurface flow artificial wetland system 9, a water inlet of the horizontal subsurface flow artificial wetland system 9 is connected with a water outlet of the bionic aquatic weed-plant wetland system 7 through a pipeline, a third control valve 8 is arranged on the pipeline, and the horizontal subsurface flow artificial wetland system 9 is provided with water outlets with different heights, the PLC water level automatic control system 10 of the subsurface flow wetland is used for controlling, so that the horizontal subsurface flow constructed wetland system 9 forms periodic water level change; the water outlet of the horizontal subsurface flow constructed wetland system 9 is connected with the water inlet of the vertical subsurface flow constructed wetland system 11, the polluted water body enters the vertical subsurface flow constructed wetland system 11 after passing through the horizontal subsurface flow constructed wetland system 9, the vertical subsurface flow constructed wetland system 11 is provided with water outlets with different heights, and the vertical subsurface flow constructed wetland system 11 is controlled by the subsurface flow wetland PLC water level automatic control system 10 to form periodic water level change; the water outlet of the vertical subsurface flow constructed wetland system 11 is connected with the water inlet of the surface flow constructed wetland system 12, and the polluted water body is discharged after passing through the surface flow constructed wetland system 12.

It is worth noting that the filter grid 1-1 is arranged at a water inlet of the water inlet system 1 and used for removing impurities and larger suspended matters in the water body, the polluted water body is filtered by the filter grid 1-1 and then enters the pretreatment system through the water inlet lift pump 1-2, a water inlet valve 1-3 and a first flow meter 1-4 are arranged between the water inlet lift pump 1-2 and the pretreatment system, and the water inlet flow is controlled through the water inlet valve 1-3 and the first flow meter 1-4.

The pre-pond system 2 comprises a pre-pond 2-1, and a continuous water lifting aeration device 2-3 and a push flow aeration device 2-4 which are arranged at the rear section of the pre-pond 2-1 and are connected and controlled through an aeration device PLC control cabinet 2-2, wherein the water lifting aeration device 2-3 and the push flow aeration device 2-4 are connected, the pre-pond 2-1 is used for precipitating suspended matters capable of being precipitated in a water body, the water lifting aeration device 2-3 and the push flow aeration device 2-4 are used for forming a fountain landscape, the hydrodynamic force and dissolved oxygen of the water body in the pre-pond 2-1 are enhanced, and the water bloom caused by poor water body fluidity in the pre-pond 2-1 is prevented. The water lifting aeration system consisting of the water lifting aeration device 2-3 and the PLC automatic timing control system of the aeration device PLC control cabinet 2-2 can automatically lift water and aerate water at regular time to form a fountain landscape, simultaneously enhance the dissolved oxygen of the water body, strengthen the effect of aerobic microorganisms of the water body and have certain removal effect on COD and ammonia nitrogen; the plug-flow aeration device 2-4 is arranged at the rear section of the front pond 2-1, can effectively enhance the water body fluidity of the front pond, increase the dissolved oxygen content of the water body, avoid the polluted water body from causing a large amount of algae growth and even generating black and odorous phenomena due to the limitation of the structure of the front pond and effectively improve the micro-ecological environment of the water body while not interfering the sedimentation of settleable suspended matters.

The nano air-flotation filter tank system 4 comprises an air-flotation tank and a nano aeration device, a polluted water body enters the air-flotation filter tank to remove suspended matters which are difficult to settle in the water body, the concentration of the suspended matters in the water body is further reduced, the dissolved oxygen of the water body is improved by the nano aeration device in a short time, the dissolved oxygen level of inlet water of the artificial wetland system is ensured, the removal effect of aerobic bacteria such as nitrobacteria on pollutants such as ammonia nitrogen, COD (chemical oxygen demand) and the like is enhanced, so that the bionic aquatic plant-plant wetland is not required to be provided with the aeration device, and the investment is reduced; the air floatation tank consists of a nano aeration tank 4-1, a solid-liquid separation tank 4-2, a clean water tank 4-3 and a scum collection tank 4-7, a nano aeration device is used for aeration of the air floatation tank to perform sufficient steam-water mixing and realize solid-liquid separation and consists of a water replenishing pump 4-4, an aeration head assembly 4-5 and a host machine 4-6, the water replenishing pump 4-4 and the aeration head assembly 4-5 are arranged in the nano aeration tank 4-1, the water replenishing pump 4-4 and the aeration head assembly 4-5 are connected to the host machine 4-6, a polluted water body enters the nano aeration tank 4-1 from a front pond to perform sufficient steam-water mixing firstly after entering the nano aeration tank 4-1, then enters the solid-liquid separation tank 4-2 to perform solid-liquid separation, suspended matters are positioned at the upper layer after being combined with nano bubbles and enter the scum collection tank 4-7, and (4) outside the discharge system, the clear water from which the suspended matters are removed enters a clear water tank 4-3 and then enters an artificial wetland system.

The microbial agent dosing system 6 comprises a ton barrel 6-1, a stirrer 6-2, a dosing valve 6-3, a dosing pump 6-4 and a second flow meter 6-5, wherein the stirrer 6-2 is installed in the ton barrel 6-1, the outlet of the ton barrel 6-1 is connected to a bionic aquatic plant-plant wetland system 7 through the dosing pump 6-4, the dosing valve 6-3 is installed at the outlet of the ton barrel 6-1, the second flow meter 6-5 is installed on a pipeline connecting the dosing pump 6-4 and the bionic aquatic plant-plant wetland system 7, and the dosing amount is controlled through the dosing valve 6-3 and the second flow meter 6-5; the microbial agent dosing system 6 adds the screened microbial agent to the artificial wetland system in the artificial wetland starting period, so that the speed of film formation of the bionic aquatic weeds and plant roots in the bionic aquatic weeds-plant wetland can be increased, the construction of the subsurface flow wetland microbial system is accelerated, the condition of poor water quality purification effect caused by relatively low microbial content in the artificial wetland system during the starting period of the subsurface flow wetland and the surface flow wetland is improved, and the water quality purification effect of the artificial wetland is enhanced.

The bionic aquatic weed-plant wetland system 7 consists of a bionic aquatic weed-plant wetland 7-1 and a bionic aquatic weed-plant floating island, wherein the bionic aquatic weed-plant floating island consists of an aquatic plant 7-2, a floating body 7-3 and a bionic aquatic weed 7-4, and after the polluted water body pretreatment system enters the artificial wetland system, the polluted water body pretreatment system firstly passes through the bionic aquatic weed-plant wetland system 7, the aquatic plant 7-2 and the bionic aquatic weed 7-4 have a certain adsorption effect and can adsorb residual suspended matters in the water body and gradually form a microbial film on the surface, thereby removing COD, ammonia nitrogen, SS, total nitrogen and total phosphorus pollutants in the water body and further reducing the concentration of the suspended matters in the inlet water of the artificial wetland.

In addition, the horizontal subsurface flow constructed wetland system 9, the subsurface flow wetland PLC water level automatic control system 10 and the vertical subsurface flow constructed wetland system 11 form the subsurface flow constructed wetland system, wherein the horizontal subsurface flow constructed wetland system 9 consists of horizontal subsurface flow constructed wetland aquatic plants 9-1 and horizontal subsurface flow constructed wetland substrates 9-2, the horizontal subsurface flow constructed wetland aquatic plants 9-1 are aquatic plant communities formed by various aquatic plants according to growth characteristics and functions, the horizontal subsurface flow constructed wetland substrates 9-2 are growth substrates of the horizontal subsurface flow constructed wetland aquatic plants 9-1 formed by various functional fillers according to constructed wetland design standards, and the water distribution of the horizontal subsurface flow constructed wetland system 9 is in the horizontal direction. The vertical subsurface flow constructed wetland system 11 consists of vertical subsurface flow constructed wetland aquatic plants 11-1 and a vertical subsurface flow constructed wetland substrate 11-2, wherein the vertical subsurface flow constructed wetland aquatic plants 11-1 are aquatic plant communities formed by various aquatic plants according to growth characteristics and functions of the aquatic plants, the vertical subsurface flow constructed wetland substrate 11-2 is a growth substrate of the vertical subsurface flow constructed wetland aquatic plants 11-1 formed by various functional fillers according to constructed wetland design standards, and the water distribution of the vertical subsurface flow constructed wetland system 11 is in a vertical direction. The PLC water level automatic control system 10 of the subsurface flow wetland consists of a PLC main control cabinet 10-1, a first electromagnetic valve 10-2, a second electromagnetic valve 10-3, a third electromagnetic valve 10-4 and a fourth electromagnetic valve 10-5, wherein the first electromagnetic valve 10-2, the second electromagnetic valve 10-3, the third electromagnetic valve 10-4 and the fourth electromagnetic valve 10-5 are all connected to the PLC main control cabinet 10-1; the subsurface flow wetland all sets up the delivery port of co-altitude not, is equipped with the solenoid valve through PLC automatic control system control on the delivery port, specifically: the horizontal subsurface flow constructed wetland system 9 is provided with water outlets with different heights, and a first electromagnetic valve 10-2 and a second electromagnetic valve 10-3 which are controlled by a PLC main control cabinet 10-1 are arranged on the water outlets; the vertical subsurface flow constructed wetland system 11 is provided with water outlets with different heights, and a third electromagnetic valve 10-4 and a fourth electromagnetic valve 10-5 which are controlled by a PLC main control cabinet 10-1 are arranged on the water outlets; the water level of the horizontal subsurface flow artificial wetland system 9 and the water level of the vertical subsurface flow artificial wetland system 11 are alternately operated according to the periodicity of high water level-low water level-high water level by controlling the automatic water level control system 10 of the subsurface flow wetland PLC and opening the water outlets with different heights at regular time.

The polluted water body passes through the bionic aquatic weed-plant wetland system 7, then enters the horizontal subsurface flow constructed wetland system 9, then enters the vertical subsurface flow constructed wetland system 11, when the polluted water body passes through the horizontal subsurface flow constructed wetland system 9 and the vertical subsurface flow constructed wetland system 11, pollutants in the water body are removed through the functions of filtration, ion exchange, plant absorption, microbial degradation and the like, meanwhile, the automatic water level control system 10 of the subsurface flow wetland PLC can automatically control the water levels of the horizontal subsurface flow constructed wetland system 9 and the vertical subsurface flow constructed wetland system 11 to be in periodic alternate operation of high level, low level and high level, so that land and water staggered zones with fixed periods are formed, anaerobic ammonia oxidation bacteria 'hot zones' are enlarged, anaerobic ammonia oxidation bacteria communities are enhanced, the anaerobic ammonia oxidation and denitrification processes of the subsurface flow constructed wetland are enhanced, and the denitrification effect of the constructed wetland is enhanced, the method realizes the complete denitrification of the polluted water body, can effectively release the ammonia nitrogen adsorbed in the filler, prolongs the service life of the filler of the artificial wetland and prolongs the service life of the artificial wetland.

It should be noted that the subsurface flow wetland is not limited to the type or combination of the subsurface flow wetland, the subsurface flow wetland is not limited to the type, function and combination of the filler, the aquatic plants planted in the subsurface flow wetland are not limited to the type and reasonable density of the aquatic plants which can normally grow under the proper climatic conditions, and the main functions of the plants are to absorb the nutrient elements such as nitrogen and phosphorus in the water body, purify the water quality, dredge the pores of the wetland and prevent blockage.

In addition, the surface flow artificial wetland system 12 comprises surface flow artificial wetland aquatic plants 12-1, the surface flow artificial wetland aquatic plants 12-1 are aquatic plant communities formed by various aquatic plants according to growth characteristics and functions thereof, the polluted water body enters the surface flow artificial wetland system 12 through the vertical subsurface flow artificial wetland system 11, and is intercepted and absorbed by the surface flow artificial wetland aquatic plants 12-1, and pollutants such as COD, total nitrogen, total phosphorus and the like in the water body are removed through degradation of microorganisms and finally discharged.

An anti-clogging and anaerobic ammonia oxidation denitrification enhancing constructed wetland technology comprises the following steps:

(1) the polluted water body is intercepted and removed with impurities and larger suspended matters through a filter grid 1-1, and then enters a pretreatment system consisting of a preposed pond system 2 and a nano air-flotation filter system 4, the settled suspended matters and COD in the polluted water body are removed through sedimentation of the preposed pond 2-1, a water lifting aeration system and a plug flow aeration system are arranged at the rear end of the preposed pond for increasing oxygen and improving the water body fluidity, the water quality deterioration caused by low dissolved oxygen content or poor fluidity of the preposed pond water body is avoided, then the polluted water body enters the nano aeration filter after passing through the preposed pond, the suspended matters which are difficult to be removed through sedimentation in the water body are removed through the nano air-flotation filter, the water body suspended matter concentration is further reduced, meanwhile, aeration is carried out on the polluted water body, and the inlet dissolved oxygen level of the artificial wetland system is improved;

(2) the polluted water enters an artificial wetland system after passing through a pretreatment system, firstly enters a bionic aquatic weed-plant wetland 7-1, further adsorbs residual suspension in the water through plant roots and bionic aquatic weeds in the water, removes soluble organic matters in the water, and is added with microorganisms by combining a microbial agent dosing system 6 to form a microbial film on the surfaces of the plant roots and the bionic aquatic weeds, remove pollutants such as SS, COD, ammonia nitrogen, total phosphorus, total nitrogen and the like in the water, simultaneously convert the ammonia nitrogen into nitrate nitrogen or nitrite nitrogen, and provide substrates for anaerobic ammonia oxidation of the subsurface wetland; then entering a multi-stage subsurface flow wetland consisting of a horizontal subsurface flow constructed wetland system 9 and a vertical subsurface flow constructed wetland system 11, and removing pollutants such as SS, COD, ammonia nitrogen, total phosphorus, total nitrogen and the like in the water body through the processes of sedimentation, filtration, adsorption, microbial degradation, plant absorption and the like; finally, the polluted water-free body enters the surface flow artificial wetland system 12, and pollutants such as nitrogen, phosphorus and the like in the water body are further removed and discharged;

(3) in the operation process of the artificial wetland system, the water level of the subsurface flow artificial wetland ecosystem is periodically adjusted through the subsurface flow wetland PLC water level automatic control system 10, the artificial wetland is controlled to keep the alternate operation mode of high water level, low water level and high water level, the artificial wetland ecosystem forms a controllable periodic land and water interlaced belt which can effectively improve the abundance of anaerobic ammonia oxidizing bacteria, further strengthening the denitrification efficiency of the anaerobic ammonia oxidizing bacteria, strengthening the anaerobic ammonia oxidizing bacteria community of the artificial wetland, strengthening the denitrification capability of the artificial wetland, removing ammonia nitrogen, nitrate nitrogen and total nitrogen content in the water body, realizing the thorough denitrification of the polluted water body, purifying the water quality, and the saturation time of the filler with the ammonia nitrogen adsorption effect in the filler of the artificial wetland can be effectively relieved, and the service life of the artificial wetland is prolonged.

It is worth noting that in the pretreatment system in the step (1), settleable suspended matters in the water body are precipitated at the front section of the preposed pond, and dissolved oxygen and mobility of the water body are enhanced at the rear section of the preposed pond by adopting a water lifting aeration and plug flow aeration mode, so that the water quality deterioration of the preposed pond water body is avoided, and secondary pollution is caused; the nano air-flotation filter tank is adopted to remove suspended matters which are difficult to settle in the water body, the concentration of the suspended matters in the water body is further reduced, the level of dissolved oxygen in the water entering the bionic aquatic plant-plant wetland can be effectively improved when the polluted water body passes through the nano air-flotation filter tank, an aeration system does not need to be arranged on the bionic aquatic plant-plant wetland system, the construction and operation cost is saved, and the treatment effect is improved.

In the step (2), the bionic aquatic weed-plant wetland is adopted to further adsorb suspended matters in the water body, the concentration of the suspended matters in the inflow water of the subsurface flow wetland is reduced, and ammonia nitrogen, COD, total phosphorus and total nitrogen in the water body are removed through a microbial film formed by a plant root system and the bionic aquatic weed; the water quality is purified by removing pollutants in the water body by adopting a mode of connecting the multi-stage artificial wetland of the bionic aquatic weed-plant wetland → the horizontal subsurface flow wetland → the vertical subsurface flow wetland → the surface flow wetland in series.

And (3) forming a controllable periodic land and water staggered belt for the artificial wetland ecosystem by the PLC water level automatic control system, wherein the land and water staggered belt is a 'hot zone' for anaerobic ammonia oxidation and denitrification, and the controllable periodic land and water staggered belt can effectively improve the abundance of anaerobic ammonia oxidation bacteria, strengthen the anaerobic ammonia oxidation and denitrification process and realize efficient denitrification.

When the embodiment works, the polluted water body is removed impurities and larger suspended matters in the water body through the filter grating 1-1, the polluted water body enters the pretreatment system through the water inlet lift pump 1-2, the polluted water body firstly passes through the preposed pond system 2 after entering the pretreatment system, the suspended matters which can be settled in the water body gradually precipitate at the front section of the preposed pond system 2, the water lifting aeration device 2-3 and the flow pushing aeration device 2-4 at the rear section of the preposed pond system 2 enhance the water power and dissolved oxygen of the preposed pond system 2-1, the water quality deterioration of the preposed pond 2-1 caused by poor water body fluidity and dissolved oxygen reduction is prevented, the polluted water body firstly enters the nano aeration tank 4-1 after entering the nano air flotation filter tank system 4 through the preposed pond treatment system 2, and is fully mixed with steam and water through the nano aeration device, part of polluted water enters a host machine 4-6 from a water replenishing pump 4-4, and is subjected to steam-water mixing → pressurized gas dissolving → gas-liquid separation → gas-liquid fluid acceleration → high-speed impact bubble crushing of enterprise fluid → secondary acceleration → release to finally form nano bubbles with negative charges on the surface, suspended particles can be effectively adsorbed and condensed, then solid-liquid separation is realized in a solid-liquid separation tank 4-2, upper-layer scum enters a scum collection tank 4-7, lower-layer clear water enters a clear water tank 4-3 and then enters a bionic aquatic plant-plant wetland system 7, the polluted water is contacted with the root system of an aquatic plant 7-2 and the bionic aquatic plant 7-4, the residual suspended substances in the water can be adsorbed on the surface by the root system of the aquatic plant 7-2 and the bionic aquatic plant 7-4 and gradually form a microbial film, and the microbial film is formed by the absorption of microbes, Degrading and removing pollutants such as SS, COD, ammonia nitrogen, total phosphorus, total nitrogen and the like in the water body; in order to accelerate the growth of microbial membranes of the bionic aquatic weed-plant wetland system 7, microbial agents are added into the bionic aquatic weed-plant wetland system 7 through a microbial agent dosing system 6, the microbial agents are added into a ton bucket 6-1 for stirring and diluting, then the microbial agents are added into the bionic aquatic weed-plant wetland system 7 through a dosing pump 6-4, the adding amount of the microbial agent dosing system is controlled through a dosing valve 6-3 and a second flowmeter 6-5, after polluted water is discharged from the bionic aquatic weed-plant wetland system 7, the polluted water firstly enters a horizontal subsurface flow artificial wetland system 9 and then enters a vertical subsurface flow artificial wetland system 11, and when the subsurface flow artificial wetland system operates, the horizontal subsurface flow artificial wetland system 9 and the vertical subsurface flow artificial wetland system 11 are automatically controlled in water level through an subsurface flow wetland PLC (programmable logic controller) water level automatic control system 10, the PLC water level automatic control system 10 of the subsurface flow wetland controls the first electromagnetic valve 10-2 and the second electromagnetic valve 10-3 of water outlets with different heights of a horizontal subsurface flow constructed wetland system 9 to be opened and closed periodically by a PLC control cabinet 10-1, and controls the third electromagnetic valve 10-4 and the fourth electromagnetic valve 10-5 of the water outlets with different heights of a vertical subsurface flow constructed wetland system 11 to be opened and closed periodically to ensure that the water level of the system is in periodic operation of high water level, low water level and high water level, strengthen the amphibious cross-over zones of the constructed wetland, enrich anaerobic ammonia oxidation bacterial communities, strengthen the denitrification capability of the constructed wetland, and remove SS, ammonia nitrogen, COD, total phosphorus, total nitrogen and other pollutants in a polluted water body through a series of actions of filtration, adsorption, plant absorption, microbial degradation, oxidation reduction and the like in the subsurface flow constructed wetland system, then enters the surface flow artificial wetland system 12, and is subjected to interception and absorption of plants and degradation of microorganisms again to remove pollutants such as COD, total nitrogen, total phosphorus and the like in the water body, purify the water quality and improve the water ecological environment.

The technical advantages of this embodiment are: the denitrification and dephosphorization effect is good: an ecological floating island is arranged in a plant filter tank in the system, and aquatic plants with high-efficiency nitrogen and phosphorus removal are planted, so that the nutrient elements such as nitrogen and phosphorus in the water body can be effectively removed, and in addition, artificial water plants, plant root systems and microorganisms form a microbial film to further remove the nutrient elements such as nitrogen and phosphorus in the water body; in addition, the subsurface flow wetland is provided with water outlets with different heights, the operating water level of the artificial wetland is controlled, a controllable land and water staggered zone is formed, anaerobic ammonium oxidation bacteria communities are enhanced, and thorough denitrification of the polluted water body is realized.

Preventing the constructed wetland from being blocked: the pretreatment of the artificial wetland adopts nano aeration, the diameter of bubbles is small, the retention time is long, the air floatation effect is good, and suspended matters in a water body can be effectively removed after artificial salvage; in addition, an ecological floating island is arranged in the ecological filter tank, aquatic plants with developed root systems are planted, artificial aquatic plants are arranged below the ecological floating island, the developed plant root systems and the artificial aquatic plants can effectively adsorb suspended matters in water, and a microbial film is formed by combining microorganisms, so that the concentration of the suspended matters entering the artificial wetland is further reduced, the blockage of the artificial wetland is prevented, and the service life of the artificial wetland is prolonged.

The specific implementation mode effectively solves the defects that the existing artificial wetland technology is relatively poor in denitrification effect, the artificial wetland filler adsorbs ammonia nitrogen to reach a saturated state, the removal effect on the ammonia nitrogen in the hand-polluted water body is poor, the content of suspended matters in the polluted water body is high, the artificial wetland is blocked and the like, the current situation of the polluted water body can be improved through the technology, pollutants such as suspended matters, organic matters, nitrogen, phosphorus and the like in the water body are effectively removed, especially, a periodic land-water staggered zone is formed by automatically controlling the water level, an anaerobic ammonia oxidation 'hot zone' is formed, the anaerobic ammonia oxidation effect is strengthened, the anaerobic ammonia oxidation denitrification of the artificial wetland is strengthened, the ammonia nitrogen adsorbed by the filler is released, and the service life of the filler is prolonged; meanwhile, the system and the technology can gradually remove the inflow suspended matters of the subsurface flow wetland in the modes of precipitation, air flotation, adsorption and the like, effectively reduce the operation load and the blocking risk of the artificial wetland, accelerate the starting speed of the artificial wetland and prolong the operation life of the artificial wetland, are mainly used for the comprehensive treatment of the watershed water environment, the landscape, the river eutrophication and the treatment of black and odorous water, and have wide market application prospect.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.