CN111977813A - Constructed wetland sewage treatment system - Google Patents

Abstract

The invention discloses a sewage treatment system of an artificial wetland, which is divided into a positive treatment mode and a back flush mode, wherein the positive treatment mode comprises the steps of feeding water through a water inlet, primarily precipitating the sewage through a precipitation tank, then feeding the sewage into a horizontal subsurface flow wetland I to remove impurities and large-particle suspended matters, then feeding the sewage into a vertical subsurface flow wetland I, completing primary treatment of the sewage through the adsorption and filtration action of a substrate and the ingestion action of a plant root system, feeding the sewage into a mixed wetland through a guide pipe to prolong the flowing time of an anoxic zone, then lifting the sewage through a reservoir and a water pump, dispersing the sewage through a spray pipe, oxygenating the water, then feeding the sewage into an aquatic plant zone through a laminated horizontal subsurface flow wetland to finally adsorb and treat the sewage, and finally discharging the sewage through a water outlet pipe. The normal service time of the wetland is prolonged, and the treatment efficiency is ensured.

Description

Constructed wetland sewage treatment system

Technical Field

The invention relates to the technical field of environmental protection, in particular to an artificial wetland sewage treatment system.

Background

The artificial wetland is a sewage treatment technology developed in the late 70 s of the 20 th century, and realizes the purification of sewage by utilizing the physical, chemical and biological synergistic action in a natural ecosystem. The artificial wetland sewage treatment technology has the main characteristics of good treatment effect, strong nitrogen and phosphorus removal capacity, convenient operation, maintenance and management, low engineering capital construction and operation and maintenance cost, strong adaptability to load change and the like, so the artificial wetland sewage treatment technology is widely used for treating domestic sewage, industrial wastewater, mine and oil exploitation wastewater, agricultural point source pollution, surface source pollution and water eutrophication problems.

The existing artificial wetland sewage treatment technology can be divided into: surface flow artificial wetland, horizontal subsurface flow artificial wetland and vertical subsurface flow artificial wetland. The sewage in the surface flow artificial wetland flows horizontally in the wetland, and the decontamination capability is limited due to the defects of large floor area, small hydraulic load rate, high dissolved oxygen requirement and the like; the sewage in the horizontal subsurface flow artificial wetland flows horizontally under the ground surface, and can remove SS (suspended solids) and part of BOD (biochemical oxygen demand) well, but the effect of removing ammonia nitrogen is poor, the nitrification process of most of the wastewater cannot be completed, the nitrification and denitrification processes of the wastewater cannot be completed independently, and the total nitrogen cannot be removed well; the sewage in the vertical subsurface flow constructed wetland is vertically percolated from the surface layer downwards, the processing capacity and the nitrification capacity of the sewage on aerobic organic matters are stronger, but the denitrification capacity is poorer, so that the two processing processes of nitrification and denitrification of the sewage cannot be independently completed, and the total nitrogen cannot be well removed.

In recent years, a combined artificial wetland sewage treatment method has been proposed. For example, chinese patent specification No. ZL03157161.1 describes a system and method for combined artificial wetland treatment of sewage, which is characterized in that: the sewage is firstly treated by a pretreatment unit, then flows into the vertical subsurface flow artificial wetland for preliminary degradation, and finally flows into the horizontal subsurface flow artificial wetland bed to further remove pollutants.

The method can integrate the advantages of the surface flow artificial wetland, the horizontal subsurface flow artificial wetland and the vertical subsurface flow artificial wetland, has certain treatment effect, but has the defects of incomplete sewage treatment, insufficient space utilization of the wetland, and influence on treatment time because all the artificial wetland sewage treatment methods need to be closed during cleaning, so that the treatment effect of the artificial wetland sewage treatment methods is limited. Therefore, the invention provides an artificial wetland sewage treatment system to solve the problems in the background art.

Disclosure of Invention

The invention aims to provide an artificial wetland sewage treatment system to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

an artificial wetland sewage treatment system comprises a plurality of peripheral ponds, a first inner pond and a second inner pond, wherein the peripheral ponds are distributed in a net shape, the first inner pond and the second inner pond which are shaped like a Chinese character 'hui' are arranged in the peripheral ponds, the left side of the peripheral ponds is connected with a water inlet, the right end of the water inlet is communicated with a sedimentation pond, the upper end of the right side of the sedimentation pond is provided with a water pipe, the water pipe is positioned at the left end of a first horizontal subsurface flow wetland between the first inner pond and the peripheral ponds, the right end of the first horizontal subsurface flow wetland is provided with a first vertical subsurface flow wetland, the left end of the lower side of the first vertical subsurface flow wetland is communicated with the lower side of the right end of the first inner pond through a guide pipe, the first inner pond is internally provided with a mixed wetland, the upper end of the left side of the mixed wetland is connected with a water storage pond, the water storage pond is, the right side of the stacked horizontal subsurface flow wetland is provided with an aquatic plant area, the lower end of the left side of the inner layer pool II is connected with a water outlet pipe,

the process of treating sewage by the artificial wetland sewage treatment method comprises the following steps:

the sewage treatment method comprises a positive treatment mode and a back flush mode, wherein water enters from a water inlet in the positive treatment mode, enters into a horizontal subsurface flow wetland I after being preliminarily precipitated by a precipitation tank, is used for removing impurities and large-particle suspended matters, then enters into a vertical subsurface flow wetland I, completes the primary treatment of the sewage by the adsorption and filtration action of a matrix and the ingestion action of a plant root system, enters into a mixed wetland through a guide pipe, prolongs the flowing time of an anoxic zone, then passes through a reservoir and a water pump for lifting, is dispersed through a spray pipe, is used for oxygenating water, then enters into an aquatic plant zone through a laminated horizontal subsurface flow wetland, is finally adsorbed and treated, and finally is discharged through a water outlet pipe.

And the back washing mode enters water through the reservoir, sequentially passes through the mixed wetland, the vertical subsurface flow wetland I and the horizontal subsurface flow wetland I, enters the sedimentation tank, and is finally discharged through the water inlet to wash the inside.

As a further aspect of the invention, the forward and backwash modes are alternated with a run time of 4: 1.

As a further scheme of the invention, the lower side of the inner-layer pool I is superposed with the lower side of the peripheral pool, the lower side of the inner-layer pool II is suspended in the inner-layer pool I through a plurality of stand columns, the laminated horizontal subsurface flow wetland is suspended in the inner-layer pool II through a plurality of stand columns, and the water outlet pipe is positioned below the laminated horizontal subsurface flow wetland.

As a further scheme of the invention, the mixed wetland comprises plant areas on the left side and the right side and a filler area on the lower side of the inner-layer pool, the filler area is filled with an adsorbent, and the adsorbent is formed by mixing coal cinder and zeolite according to the volume ratio of 1: 1.

As a further scheme of the invention, the stacked horizontal subsurface flow wetland is composed of a plurality of terraces with trapezoidal spans, the highest terrace is higher than the upper end of the mixed wetland, and the lowest terrace is flush with the aquatic plant area to form gradient water flow, so that the flow of the water flow is accelerated.

In a still further aspect of the present invention, submerged plants and floating plants are planted in the aquatic plant area, the submerged plants are at least one of eel grass, watermifoil, hydrilla verticillata, goldfish algae, goldfish grass, potamogeton malaianus and hypsizygus marmoreus, and the floating plants are at least one of submerged plants such as water hyacinth, water lily, and Japanese pagodatree.

As a further scheme of the invention, the horizontal subsurface flow wetland I, the vertical subsurface flow wetland I, the mixed wetland and the laminated horizontal subsurface flow wetland are divided into a plurality of layers, a fine sand combination layer, a coarse sand combination layer and a gravel layer are sequentially arranged from top to bottom, and each layer is primarily isolated through a planting net, so that later-stage cleaning is facilitated.

As a further scheme of the invention, an inclined filter screen is arranged in the sedimentation tank to primarily filter sewage, and the water pump is suspended in the water storage tank to leave a space for sedimentation.

Compared with the prior art, the invention has the beneficial effects that:

the invention carries out back flush on the peripheral tank through a positive treatment mode and a back flush mode, prolongs the normal service time of the wetland and ensures the treatment efficiency.

The constructed wetland sewage treatment system obviously and effectively improves the biological diversity and the ecological diversity, forms spatial three-dimensional distribution and time continuous distribution, has fixed local water body service area and is full in overall space.

The invention can perform partition cleaning according to a plan during cleaning through the mesh distribution, and can still perform a treatment process in the cleaning process.

According to the invention, by prolonging the flow path of water flow and decomposing the microorganisms, organic matters, nitrogen and phosphorus in the sewage are removed through oxidative decomposition, nitrification and denitrification, so that the purification effect of the water body is greatly improved.

The invention has certain landscape function.

Drawings

Fig. 1 is a schematic top view of an artificial wetland sewage treatment system.

Fig. 2 is a schematic sectional structure view of an artificial wetland sewage treatment system.

Fig. 3 is a schematic view of a positive treatment mode in the constructed wetland sewage treatment system.

Fig. 4 is a schematic diagram of a backwashing mode in the artificial wetland sewage treatment system.

Fig. 5 is a schematic structural diagram of a horizontal subsurface flow wetland I, a vertical subsurface flow wetland I, a mixed wetland and the upper layer and the lower layer in a laminated horizontal subsurface flow wetland in an artificial wetland sewage treatment system.

In the figure: 1. a peripheral pool; 2. an inner layer pool I; 3. a second inner layer pool; 4. a water inlet; 5. a sedimentation tank; 6. a filter screen; 7. horizontal subsurface flow wetland I; 8. vertical subsurface flow wetland I; 9. a flow guide pipe; 10. mixing the wet land; 11. a reservoir; 12. a water pump; 13. a nozzle; 14. stacking the horizontal subsurface flow wetland; 15. an aquatic plant area; 16. a water outlet pipe; 17. planting a net; 18. a fine sand composite layer; 19. a coarse sand composite layer; 20. a gravel layer.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 5, in the embodiment of the invention, an artificial wetland sewage treatment system comprises aperipheral tank 1, aninner layer tank 2 and aninner layer tank 3, wherein the lower side of theinner layer tank 2 coincides with the lower side of theperipheral tank 1, the lower side of theinner layer tank 3 is suspended in theinner layer tank 2 through a plurality of stand columns, a laminated horizontalsubsurface flow wetland 14 is suspended in theinner layer tank 3 through a plurality of stand columns, a plurality of theperipheral tanks 1 are distributed in a net shape, theperipheral tank 1 is internally provided with theinner layer tank 2 and theinner layer tank 3 in a shape of a Chinese character 'hui', the left side of theperipheral tank 1 is connected with awater inlet 4, the right end of thewater inlet 4 is communicated with asedimentation tank 5, the right upper end of thesedimentation tank 5 is provided with a water pipe, the water pipe is positioned at the left end of the horizontal subsurface flow wetland 7 between theinner layer tank 2 and theperipheral tank 1, the right end of the horizontal subsurface flow wetland 7 is provided with a verticalsubsurface flow wetland 8, the left end of the lower side of, themixed wetland 10 is arranged in the inner layer pool I2, the upper end of the left side of themixed wetland 10 is connected with areservoir 11 through a water pipe, thereservoir 11 is positioned at the left side of the inner layer pool II 3, awater pump 12 is arranged in thereservoir 11, thewater pump 12 is connected with aspray pipe 13 through a water pipe, thespray pipe 13 is positioned at the upper side of the left end of the laminated horizontalsubsurface flow wetland 14, the right side of the laminated horizontalsubsurface flow wetland 14 is provided with anaquatic plant area 15, the lower end of the left side of the inner layer pool,

the process of treating sewage by the artificial wetland sewage treatment method comprises the following steps:

the sewage treatment method comprises a positive treatment mode and a back flush mode, wherein water is fed through awater inlet 4 in the positive treatment mode, the sewage enters a horizontal subsurface flow wetland I7 after being primarily precipitated through aprecipitation tank 5, impurities and large-particle suspended matters are removed, the sewage enters a vertical subsurface flow wetland I8, the primary treatment of the sewage is completed through the adsorption and filtration action of a matrix and the ingestion action of a plant root system, the sewage enters amixed wetland 10 through aguide pipe 9, the flowing time of an anoxic zone is prolonged, the sewage enters areservoir 11 and awater pump 12 for lifting, is dispersed through aspray pipe 13, the water is oxygenated, then enters anaquatic plant zone 15 through a laminated horizontalsubsurface flow wetland 14, is finally adsorbed and treated, and is finally discharged through awater outlet pipe 16.

And the back flushing mode is that water enters through areservoir 11, sequentially passes through amixed wetland 10, a vertical subsurface flow wetland I8 and a horizontal subsurface flow wetland I7, enters asedimentation tank 5, and is finally discharged through awater inlet 4 to flush the inside.

The positive treatment mode and the back flush mode are alternately carried out, and the running time is 4: 1.

The mixed wetland 10 comprises plant areas on the left side and the right side and a filler area on the lower side of the inner-layer pool II 3, the filler area is filled with an adsorbent, and the adsorbent is prepared from coal cinder and zeolite according to a volume ratio of 1:1, the stacked horizontal subsurface flow wetland 14 is formed by a plurality of terraces with trapezoidal spans, the highest terrace is higher than the upper end of the mixed wetland 10, the lowest terrace is flush with the aquatic plant area 15 to form gradient water flow and accelerate the flow of the water flow, submerged plants and floating plants are planted in the aquatic plant area 15, and the submerged plants are at least one of tape grass, watermifoil, hydrilla verticillata, goldfish algae, goldfish grass, potamogeton malaianus and seaweed flowers; the floating plants are at least one of the submerged plants such as the aeolian crassipes, the water lily, the duckweed and the like, the horizontal subsurface flow wetland 7, the vertical subsurface flow wetland 8, the mixed wetland 10 and the laminated horizontal subsurface flow wetland 14 are equally divided into a plurality of layers, the fine sand combined layer 18, the coarse sand combined layer 19 and the gravel layer 20 are sequentially arranged from top to bottom, preliminary separation is carried out between each layer through the planting net 17, later-period cleaning is facilitated, the inclined filter screen 6 is arranged in the sedimentation tank 5, sewage is preliminarily filtered, and the water pump 12 is installed in the reservoir 11 in a suspended mode and leaves a space for sedimentation.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims (7)

1. An artificial wetland sewage treatment system comprises a peripheral tank (1), a first inner-layer tank (2) and a second inner-layer tank (3), and is characterized in that a plurality of the peripheral tanks (1) are distributed in a net shape, the first inner-layer tank (2) and the second inner-layer tank (3) are arranged in the peripheral tank (1), the left side of the peripheral tank (1) is connected with a water inlet (4), the right end of the water inlet (4) is communicated with a sedimentation tank (5), the right upper end of the sedimentation tank (5) is provided with a water pipe, the water pipe is positioned at the left end of a horizontal undercurrent wetland (7) between the first inner-layer tank (2) and the peripheral tank (1), the right end of the horizontal undercurrent wetland (7) is provided with a first vertical undercurrent wetland (8), the left end of the lower side of the vertical undercurrent wetland (8) is communicated with the lower side of the right end of the first inner-layer tank (2) through a guide pipe, the upper end of the left side of the mixed wetland (10) is connected with a reservoir (11) through a water pipe, the reservoir (11) is positioned on the left side of the inner layer pool II (3), a water pump (12) is arranged in the reservoir (11), the water pump (12) is connected with a spray pipe (13) through a water pipe, the spray pipe (13) is positioned on the upper side of the left end of the stacked horizontal subsurface flow wetland (14), an aquatic plant area (15) is arranged on the right side of the stacked horizontal subsurface flow wetland (14), and the lower end of the left side of the inner layer pool II (3) is connected.

2. The constructed wetland sewage treatment system according to claim 1, wherein the lower side of the first inner layer tank (2) coincides with the lower side of the peripheral tank (1), the lower side of the second inner layer tank (3) is suspended in the first inner layer tank (2) through a plurality of columns, the stacked horizontal subsurface flow wetland (14) is suspended in the second inner layer tank (3) through a plurality of columns, and the water outlet pipe (16) is positioned below the stacked horizontal subsurface flow wetland (14).

3. The artificial wetland sewage treatment system according to claim 1, wherein the mixed wetland (10) comprises plant areas on the left and right sides and a filler area on the lower side of the inner pond II (3), the filler area is filled with an adsorbent, and the adsorbent is prepared from coal slag and zeolite in a volume ratio of 1:1 are mixed.

4. The constructed wetland sewage treatment system according to claim 1, characterized in that the stacked horizontal subsurface wetland (14) is composed of terraces with trapezoidal spans, the highest terrace being higher than the upper end of the mixed wetland (10), and the lowest terrace being level with the aquatic plant area (15).

5. The constructed wetland sewage treatment system according to claim 1, wherein the aquatic plant area (15) is planted with submerged plants and floating plants, the submerged plants are at least one of eel grass, watermifoil, hydrilla verticillata, goldfish algae, goldfish grass, potamogeton malaianus and hypnea flower, and the floating plants are at least one of water hyacinth and water lily and sophora alopecuroides submerged plants.

6. The constructed wetland sewage treatment system according to claim 1, wherein the horizontal subsurface flow wetland I (7), the vertical subsurface flow wetland I (8), the mixed wetland (10) and the laminated horizontal subsurface flow wetland I (14) are divided into a plurality of layers, namely a fine sand combined layer (18), a coarse sand combined layer (19) and a gravel layer (20) from top to bottom, and each layer is primarily blocked by a planting net (17).

7. The artificial wetland sewage treatment system according to claim 1, wherein an inclined filter screen (6) is arranged in the sedimentation tank (5), and the water pump (12) is suspended in the reservoir (11).

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