A multifunctional composite artificial wetland sewage treatment system

Abstract

The present invention proposes a multifunctional composite artificial wetland sewage treatment system, including an artificial wetland pool body and a water collection channel arranged adjacently, a water distribution weir is arranged along the inner wall of the surrounding masonry of the artificial wetland pool body, a packing layer is arranged inside, a shallow water layer is formed on the packing layer through a water level regulating device, wetland plants are introduced into the water distribution weir, emergent plants are planted on the top of the packing layer, the top surface of the water distribution weir is higher than the top surface of the packing layer, a cover plate is arranged on the top of the water collection channel, a drainage pipe is arranged at the bottom, a water collection pipe is arranged horizontally at the bottom of the artificial wetland pool packing layer, one end of the water collection pipe is connected to a vertically arranged vent pipe, and the other end passes through the masonry and is connected to a water outlet pipe arranged vertically in the water collection channel, and water collection holes are evenly spaced on the water collection pipe, and the top of the vent pipe is higher than the top surface of the packing layer and communicates with the atmosphere. The present invention integrates the advantages of shallow flow wetlands and subsurface flow wetlands, combines slow filtration with biological purification technology, has a high pollutant area load, occupies a small area, has low cost, and has more stable water output.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a multifunctional composite artificial wetland sewage treatment system. Background Art

[0002] In the field of purification of slightly polluted water and upgrading of tailwater discharged from sewage treatment plants, artificial wetland sewage treatment technology is favored and used more and more widely due to its low operating cost, simple maintenance and management, good purification effect and closer to ecology and nature. At present, the application scope of surface flow artificial wetlands is greatly limited due to low pollutant area load, large land area and difficulty in operation and maintenance, and needs to be selected according to local conditions; compared with surface flow wetlands, subsurface flow wetlands have a larger pollutant area, small land area and simple maintenance and management, so they are widely used, but there are also large amounts of wetland fillers, high investment costs and limited construction scale. At the same time, subsurface flow wetlands have the defects of reduced purification efficiency and unstable water output after the wetland plants are harvested in winter.

[0003] Therefore, in the field of applying artificial wetland sewage treatment technology to treat slightly polluted natural water bodies or to deeply purify the tail water discharged from sewage treatment plants, there is a need for the birth of a new artificial wetland sewage treatment technology with a high pollutant area load, a small footprint, and more stable effluent. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a multifunctional composite artificial wetland sewage treatment system for the above-mentioned problems, which utilizes the advantages of shallow flow and vertical subsurface flow wetlands to treat polluted river water, black and smelly water and tail water from sewage treatment plants.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a multifunctional composite artificial wetland sewage treatment system, characterized in that it includes adjacently arranged artificial wetland pool bodies and water collection channels, the artificial wetland pool bodies are provided with water distribution weirs along the inner walls of the surrounding masonry, a filler layer is provided inside the artificial wetland pool bodies, a shallow water layer is formed on the filler layer by a water level regulating device, wetland plants are introduced into the shallow water layer, emergent plants are planted on the top of the filler layer, the top surface of the water distribution weir is higher than the top surface of the shallow water layer, a cover plate is provided on the top of the water collection channel, a drainage pipe is provided at the bottom, a water collection pipe is horizontally provided at the bottom of the filler layer of the artificial wetland pool, one end of the water collection pipe is connected to a vertically arranged ventilation pipe, and the other end passes through the masonry and is connected to a water outlet pipe vertically arranged in the water collection channel, water collection holes are evenly spaced on the water collection pipe, and the top of the ventilation pipe is higher than the top surface of the filler layer and communicates with the atmosphere.

[0006] According to the above scheme, the water collecting pipes are arranged in blocks along the bottom of the artificial wetland pool, and each block has an area of ​​less than 800m 2A plurality of water collecting pipes are evenly spaced horizontally on each block, and the ports at both ends of the plurality of water collecting pipes are connected through connecting pipes respectively, and the centers of the connecting pipes at both ends are respectively connected to the bottom of the ventilation pipe and the water outlet pipe.

[0007] According to the above scheme, the water level regulating device is a rotating elbow, the two ends of the rotating elbow are respectively connected to the connecting pipe and the water outlet pipe, and the top of the water outlet pipe is a bell mouth.

[0008] According to the above scheme, the packing layer is divided into three layers from top to bottom, namely, a fine particle size filtration layer, a medium particle size adsorption reaction layer, and a coarse particle size water collection layer, and the thickness of each layer is 0.3m to 0.5m.

[0009] According to the above scheme, the filler is one or more combinations of crushed stone, gravel, stone chips, coarse sand, coal slag, industrial waste residue or artificial synthetic filler.

[0010] According to the above scheme, the particle sizes of each layer of the filler layer from top to bottom are 8-15 mm, 15-25 mm, and 30-60 mm respectively.

[0011] According to the above solution, the water distribution weir is a steel-concrete structure or a stainless steel structure.

[0012] According to the above scheme, the height difference between the top surface of the water distribution weir and the top surface of the shallow water layer is 20cm to 30cm.

[0013] According to the above scheme, the wetland plants are filamentous algae and / or shallow water floating leaf plants.

[0014] According to the above scheme, the ventilation pipe, water collecting pipe, connecting pipe and water outlet pipe are all UPVC pipes.

[0015] The beneficial effects of the present invention are as follows: 1. It provides a multifunctional composite artificial wetland sewage treatment system. The combination of shallow flow wetland and vertical flow wetland improves the oxygen enrichment capacity and pollutant area load of the wetland, saves the wetland area and reduces investment; 2. It combines slow filtration with biological purification technology and utilizes the self-purification ability of the water ecosystem to make up for the disadvantage of low TN removal rate of subsurface flow artificial wetland in treating low C / N ratio sewage types, thereby improving the purification efficiency of the wetland; 3. It utilizes the shallow water layer for water distribution, with small head loss, uniform water distribution and high wetland area utilization rate. At the same time, the sewage penetrates the wetland bed layer by slow filtration, which makes the pollutant interception more thorough, the effluent SS concentration is low and the water purification effect is good; 4. A rotating elbow is used to adjust the height of the outlet bell mouth of the outlet pipe to realize flexible adjustment of the water level of the shallow water layer, making the wetland operation more flexible, simple to operate and low in operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0018] like Figure 1 As shown, a multifunctional composite artificial wetland sewage treatment system comprises an artificial wetland pool body 1 and a water collection channel 2 which are adjacently arranged. The artificial wetland pool body and the water collection channel are both composed of a base and surrounding masonry edges. A water distribution weir 3 is arranged along the inner wall of the surrounding masonry of the artificial wetland pool body. A filler layer is arranged inside the artificial wetland pool. After the water distribution weir distributes water, a shallow water layer 4 is formed on the filler layer through a water level regulating device. Wetland plants 5 are introduced into the shallow water layer. Emergent plants 6 are planted on the top of the filler layer. The top surface of the water distribution weir is higher than the top surface of the shallow water layer. A cover plate 7 is arranged on the top of the water collection channel, and a drainage pipe 8 is arranged at the bottom. A water collection pipe 9 is horizontally arranged at the bottom of the filler layer of the artificial wetland pool. One end of the water collection pipe is connected to a vertically arranged ventilation pipe 10, and the other end passes through the masonry and is connected to a water outlet pipe 11 vertically arranged in the water collection channel. Water collection holes 12 are evenly spaced on the water collection pipe, and the top of the ventilation pipe is higher than the top surface of the filler layer and communicates with the atmosphere.

[0019] When the sewage treatment system is in operation, water first enters the water distribution weir and evenly distributes water to the artificial wetland pool, forming a shallow water layer on the top of the filler layer. After passing through each layer of filler from top to bottom, water enters the water collection pipe through the water collection hole, and then flows into the water collection channel through the trumpet at the top of the outlet pipe.

[0020] The water distribution weir adopts steel-concrete structure to be constructed together with the pool wall, or is installed with stainless steel integral weir trough. The water distribution weir distributes water evenly on all sides at the same time. The height difference between the weir top and the shallow water layer is controlled at 20 to 30 cm. The water from the weir top forms a waterfall to realize the waterfall oxygenation process.

[0021] The water collection pipes are laid out in blocks along the bottom of the artificial wetland pool, with each block less than 800m 2 Multiple water collecting pipes are evenly spaced horizontally in each block. The ends of the multiple water collecting pipes are connected through connecting pipes. The centers of the connecting pipes at both ends are connected to the bottom of the vent pipe and the outlet pipe. The vent pipe, water collecting pipe, connecting pipe and outlet pipe are all UPVC pipes.

[0022] The bottom end of the outlet pipe is connected to the connecting pipe through a rotating elbow 13, and a bell mouth 14 is provided at the top of the outlet pipe. The rotation of the rotating elbow drives the outlet pipe to rotate from a horizontal position to a vertical position. The height of the outlet bell mouth is changed by adjusting the angle of the outlet pipe, thereby realizing the adjustment of the water level of the shallow water layer to adapt to different operating conditions of the wetland. In winter, the depth of the shallow water layer can be appropriately increased to play a role in heat preservation; during the plant harvesting season, the water level can be temporarily lowered to below the filler layer to facilitate the harvesting and maintenance of wetland plants; the setting of the bell mouth makes the outlet water fall in an umbrella shape, making full use of the head loss of the wetland to oxygenate the water body.

[0023] The water level of the shallow water layer is adjusted to control the water depth at 20-30cm. After the waterfalls on the surrounding weirs, the water flow resistance of the shallow water layer in the horizontal direction is much smaller than the flow resistance of the water in the filler layer and is almost zero. The head loss of the surface water passing through the wetland filler layer mainly comes from the flow resistance in the vertical direction of the filler layer. The resistances in the vertical direction are basically equal, which can ensure the uniformity of water distribution in the wetland unit and improve the utilization efficiency of the wetland unit area.

[0024] Plant filamentous algae and shallow-water floating-leaf plants in the shallow water layer. After a period of operation, floating algae, attached algae and other micro-animals can grow on their own. The photosynthesis of algae provides food and dissolved oxygen for animals. Aquatic animals feed on floating algae, and the two form a benign water ecosystem. At the same time, the growth of aquatic animals can attract a large number of birds to inhabit. After the emergence of plants, they can provide a hidden habitat for birds. The entire wetland ecosystem is born naturally and complements each other. Using the principle of slow filtration biological purification, various algae, protozoa, metazoa and other microorganisms are cultivated in the shallow water layer to form a stable ecosystem to adsorb and degrade SS and pollutants in the influent water. At the same time, the photosynthesis of algae releases microbubbles of O2 that are easily soluble in water, creating a good oxygen-rich environment for the water body and promoting the oxidation of ammonia nitrogen and organic matter (relevant research data show that the dissolved oxygen in the water of cyanobacteria can reach a supersaturated state in summer). Algae and dead microorganisms in the shallow water layer sink to the upper part of the wetland bed and are intercepted by the fine fillers on the surface. When they reach a certain thickness, they become anaerobic and are converted into soluble organic matter, which can provide a carbon source for denitrifying bacteria in the wetland bed, solve the problem of low C / N in similar water bodies such as slightly polluted natural water bodies and sewage plant tail water, create denitrification conditions for denitrifying bacteria, and improve the TN removal effect of artificial wetlands.

[0025] Emergent plants are planted on the top of the filler layer. Their well-developed root systems can transport oxygen to the deep wetland bed for use by the biofilm on the filler. At the same time, the plants absorb a large amount of N, P and other elements during their growth. In addition, in the high temperature season in summer, the stems and leaves of the plants can block sunlight and lower the water temperature, which can inhibit the massive reproduction of algae in the shallow water layer in summer and improve the wetland environment.

[0026] From late spring to early autumn, the rapid growth of emergent plants can not only absorb a large amount of N, P and other elements in the water, but the developed root system can also provide a place for microorganisms to attach and transport oxygen. At the same time, the tall stems and leaves can block the sunlight and reduce the surface water temperature, which can avoid the massive reproduction and death of algae in the high temperature season, affecting the treatment effect and wetland environment. After the emergent plants are harvested in autumn, the shallow water ecosystem gradually plays a leading role. The growth of algae provides a good attachment environment and dissolved oxygen conditions for the growth of microorganisms, and purifies the water quality in a water ecological way. In addition, the shallow water layer water slowly penetrates the wetland bed and flows out from the evenly perforated water collection pipe at the bottom. When passing through the wetland bed, the pollutants are intercepted, adsorbed and degraded by the wetland filler and microorganisms, combining the advantages of shallow flow and vertical flow wetlands, improving the purification effect of artificial wetlands in winter.

[0027] The filler layer is divided into three layers from top to bottom, which are a fine-particle filtration layer 15, a medium-particle adsorption reaction layer 16, and a coarse-particle water collection layer 17. The total thickness of the filler layer is 0.8m to 1.2m. The filler can be crushed stone, gravel, stone chips, coarse sand, coal slag, other industrial waste residues and artificial synthetic fillers. When the sewage slowly passes through the wetland bed vertically, the pollutants are effectively removed under the multiple effects of filler adsorption, microbial degradation and plant root absorption.

[0028] The present invention integrates the advantages of shallow surface flow wetlands and subsurface flow wetlands through technological innovation, and combines slow filtration with biological purification technology. It not only has the dual functions of waterfall oxygenation and algae photosynthesis oxygen release, creating an oxygen-rich environment for wetland water inlet and increasing the pollutant area load of the wetland; at the same time, the photosynthesis of algae in the shallow water layer can produce organic matter by itself, providing a carbon source for denitrifying bacteria in the wetland bed, solving the problem of low TN removal rate caused by imbalance of carbon-nitrogen ratio in micro-polluted water bodies; in addition, the shallow water layer has the performance of low resistance water distribution and uniform water distribution, avoiding the formation of dead water areas and improving the utilization rate of the wetland area. Its unique water level regulation function can adapt to the demand for wetland water level in different seasons, and the effluent water quality is more stable.

Claims

1. A multifunctional composite artificial wetland sewage treatment system, characterized in that: It comprises an artificial wetland pool body and a water collection channel arranged adjacent to each other, wherein the artificial wetland pool body is provided with a water distribution weir along the inner wall of the surrounding masonry, a packing layer is arranged inside the artificial wetland pool body, a shallow water layer is formed on the packing layer through a water level regulating device, wetland plants are introduced into the shallow water layer, and emergent plants are planted on the top of the packing layer. The top surface of the water distribution weir is higher than the top surface of the shallow water layer, a cover plate is arranged on the top of the water collection channel, a drainage pipe is arranged at the bottom, a water collection pipe is arranged horizontally at the bottom of the packing layer of the artificial wetland pool, one end of the water collection pipe is connected to a vertically arranged ventilation pipe, and the other end passes through the masonry and is connected to a water outlet pipe arranged vertically in the water collection channel, water collection holes are evenly spaced on the water collection pipe, and the top end of the ventilation pipe is higher than the top surface of the packing layer and communicates with the atmosphere; the water collection pipe is arranged in blocks along the bottom of the artificial wetland pool, and the area of ​​each block is less than 800m 2 A plurality of water collecting pipes are evenly spaced horizontally on each block, and the ports at both ends of the plurality of water collecting pipes are connected through connecting pipes respectively, and the centers of the connecting pipes at both ends are respectively connected with the ventilation pipe and the bottom of the water outlet pipe; the water level regulating device is a rotating elbow, and the two ends of the rotating elbow are respectively connected with the connecting pipe and the water outlet pipe, and the top of the water outlet pipe is a bell mouth; the packing layer is divided into three layers from top to bottom, which are a fine particle size filtration layer, a medium particle size adsorption reaction layer, and a coarse particle size water collecting layer, and the thickness of each layer is 0.3m to 0.5m.

2. A multifunctional composite artificial wetland sewage treatment system according to claim 1, characterized in that: The filler is one or more combinations of crushed stone, gravel, stone chips, coarse sand, coal slag, industrial waste residue or artificial synthetic filler.

3. A multifunctional composite artificial wetland sewage treatment system according to claim 1 or 2, characterized in that: The particle sizes of each layer of the filler layer from top to bottom are 8-15 mm, 15-25 mm, and 30-60 mm respectively.

4. A multifunctional composite artificial wetland sewage treatment system according to claim 1, characterized in that: The water distribution weir is a steel-concrete structure or a stainless steel structure.

5. A multifunctional composite artificial wetland sewage treatment system according to claim 1 or 4, characterized in that: The height difference between the top surface of the water distribution weir and the top surface of the shallow water layer is 20 cm to 30 cm.

6. The multifunctional composite artificial wetland sewage treatment system according to claim 1 is characterized in that: The wetland plants are filamentous algae and / or shallow water floating leaf plants.

7. The multifunctional composite artificial wetland sewage treatment system according to claim 1 is characterized in that: The ventilation pipe, water collecting pipe, connecting pipe and water outlet pipe are all UPVC pipes.

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