Surface flow constructed wetland device for efficiently purifying high-salt low-biodegradability micro-polluted water and operation method

Abstract

The invention discloses a surface flow constructed wetland device for efficiently purifying high-salt low-biodegradability micro-polluted water and an operation method, the surface flow constructed wetland device comprises a bent flow channel unit, the bent flow channel unit is composed of a plurality of stages of subunits which are connected in series through drop water stepping, each stage of subunit comprises a supporting layer, a deep pool and a shoal, and the deep pool and the shoal are arranged on one side of the top of the supporting layer; the bottoms of the deep pool and the shoal are paved with sintering material layers which have porous adsorption and can promote expression of microbial functional genes, a filtering wall is arranged at the position, corresponding to the groove, of the outer side of the drop water-filled step, and the filtering wall is made into a frame through iron wires and is filled with composite porous filler. According to the invention, the hydraulic mixing effect and the oxygen transfer efficiency are obviously improved by combining the multi-stage bent flow channel and the drop water heater step with the shoal-pool alternate layout; the sintering material layer is matched with the composite porous filler, so that pollutant adsorption is enhanced, and meanwhile, the treatment stability is guaranteed by promoting microbial gene function expression; therefore, compared with a conventional surface flow wetland, the removal rate of CODCr, nitrogen, phosphorus and other pollutants is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial wetlands, in particular to a surface flow artificial wetland device and an operating method for efficiently purifying high-salinity, low-biodegradability, slightly polluted water. Background Art

[0002] Constructed wetlands are comprehensive ecosystems that apply the principles of species symbiosis, material recycling, and the coordination of structure and function. While promoting the virtuous cycle of pollutants in wastewater, they fully utilize the productive potential of resources, prevent environmental re-pollution, and achieve optimal benefits from wastewater treatment and resource utilization. Constructed wetland plants also deliver oxygen to the water and increase its activity. Wetland plants also play a vital role in controlling water pollution and degrading harmful substances. Compared to subsurface constructed wetlands, surface constructed wetlands offer advantages such as lower construction costs, simpler operation and maintenance, and a lack of clogging. They are widely used in resource-rich regions such as Northwest my country.

[0003] However, surface flow artificial wetlands generally have the problem of low operating efficiency. For example, the patent with application number 202310661907.1 uses a multi-stage structure of ceramic block layer-activated carbon layer-stone layer to treat conventional sewage. Although it can improve the purification effect, when treating low biodegradable and low carbon source industrial tail water, COD Cr The removal rate of pollutants such as COD is significantly reduced, and COD Cr In addition, arid and semi-arid regions such as Northwest my country are affected by geological and climatic factors, which lead to increased salinity in surface flow constructed wetlands, further reducing the removal rate of pollutants. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above problems or at least partially solve the above problems, and to propose a surface flow artificial wetland device and operation method for efficiently purifying high-salinity, low-biodegradability, slightly polluted water.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a surface flow artificial wetland device for efficiently purifying high-salt, low-biodegradability, slightly polluted water, including a curved flow channel unit, which is composed of several levels of sub-units connected in series through waterfall stepping stones, each level of sub-units including a supporting layer, a deep pool and a shallow beach on one side of the top of the supporting layer, and artificial aquatic plants on the other side of the top thereof, wherein the deep pool is planted with salt-tolerant submerged plants, and the shallow beach is planted with salt-tolerant emergent plants, and the bottom of the deep pool and the shallow beach is paved with a sintered material layer with porous adsorption and capable of promoting the expression of microbial functional genes, the top of the waterfall stepping stone has a plurality of grooves, and aeration holes are provided in the grooves, and a filter wall is provided on the outer side of the waterfall stepping stone corresponding to the grooves, and the filter wall is made of an iron wire frame and filled with composite porous fillers.

[0006] In a preferred embodiment, the shallows and deep pools are arranged alternately.

[0007] In a preferred embodiment, the emergent plants are reeds, cattails or water plantains, with a planting density of 10-20 plants / m²; the submerged plants are water chestnuts or foxtail algae, with a planting density of 20-30 plants / m²; the artificial aquatic plants are made of polyester fiber, with a laying density of 3-5 plants / m², and the laying area is 20%-40% of the total area.

[0008] In a preferred embodiment, the sintered material layer is formed by mixing dehydrated aluminum sludge and reed straw and sintering them.

[0009] In a preferred embodiment, the composite porous filler of the filter wall is waste sponge iron and volcanic rock, and the ratio of the waste sponge iron to the volcanic rock is 1:1-1:2.

[0010] In a preferred embodiment, the interior of the stepping stone further comprises a channel connected to the aeration holes, and the channel is connected to an external aeration device.

[0011] A method for operating a surface flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water comprises the following steps: Influent regulation: high-salinity, low-biodegradability, slightly polluted water is introduced into the surface flow artificial wetland device to control the influent salinity below 3500 mg / L, BOD5 / COD Cr The hydraulic load is maintained at 0.1-0.3 m³ / (m²·d) and the number of operating sub-units is adjusted by pumping water according to the flow changes in the dry season to keep the hydraulic load at the optimal value of 0.2 m³ / (m²·d); In hierarchical treatment, sewage flows through the sub-units of the curved flow unit in sequence. Each sub-unit is connected in series by waterfall stepping stones. Shallows and deep pools are set alternately in the sub-units. Salt-tolerant emergent plants are planted in the shallows, and salt-tolerant submerged plants are planted in the deep pools to promote the degradation of pollutants. The system flow rate is maintained at 0.5m / s through hydraulic regulation. When the flow rate is insufficient, the water propeller is activated; Composite purification: when sewage flows through the waterfall stepping stone, it is naturally aerated and reoxygenated through the aeration holes in its grooves; the water flows through the filter wall, and the waste sponge iron and volcanic rock filled in the filter wall work together to release ferrous ions through micro-corrosion to promote denitrification, and at the same time adsorb pollutants. At the same time, the sintered material layer at the bottom enhances degradation through porous adsorption and microbial functional gene regulation.

[0012] Compared with the existing technology, the present invention provides a surface flow artificial wetland device and operation method for efficiently purifying high-salinity, low-biodegradability, slightly polluted water, which can stably treat the influent salinity below 3500 mg / L and the BOD5 / COD CrOnly 0.25 of low biodegradability of sewage treatment plant tail water, while compatible with lower salinity or BOD5 / COD Cr It effectively solves the technical difficulties of traditional surface wetlands in treating high-salinity and low-biodegradability sewage. By adopting a multi-stage curved flow channel and a waterfall stepping stone in series structure design, combined with a shallow-deep pool alternating layout, it significantly improves the hydraulic mixing effect and oxygen transfer efficiency, making COD Cr The removal rate is improved compared with conventional surface flow wetlands; the sintered material layer mixed with dehydrated aluminum sludge and reed straw is combined with the composite porous filler of sponge iron and volcanic stone to enhance the adsorption of pollutants while promoting the expression of microbial gene function to ensure the treatment stability and ensure the BOD5 / COD Cr It can still maintain stable processing effect when it is as low as 0.25. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a layout diagram of the surface flow artificial wetland of the present invention; Figure 2 This is a top view layout of the deep pool and shallow beach of the present invention; Figure 3 It is a schematic diagram of the three-dimensional structure of the waterfall stepping and filter wall in the present invention.

[0014] In the figure: 1. Support layer; 2. Sintered material layer; 3. Deep pool; 4. Shallow beach; 5. Emergent plants; 6. Submerged plants; 7. Artificial aquatic plants; 8. Waterfall stepping stone; 81. Aeration hole; 9. Filter wall. DETAILED DESCRIPTION

[0015] The present invention will be further described in detail below with reference to the accompanying drawings.

[0016] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this description, those skilled in the art may make creative modifications to the embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

[0017] The present invention provides a surface flow artificial wetland device and operation method for efficiently purifying high-salinity, low-biodegradability, slightly polluted water, which solves the technical problems in the prior art. The overall concept is as follows: Example 1:

[0018] See also Figure 1-Figure 3; A surface flow artificial wetland device for efficiently purifying high-salt, low-biodegradability, slightly polluted water, includes a curved flow channel unit, which is composed of several levels of sub-units connected in series through a waterfall step 8, with a curvature (actual length divided by straight line length) of 1.2~1.5, which can effectively eliminate dead water areas and promote the growth of microorganisms. Each sub-unit includes a supporting layer 1, a deep pool 3 and a shallow beach 4 on one side of the top of the supporting layer 1, and artificial aquatic plants 7 on the other side of the top thereof, wherein the deep pool 3 is planted with salt-tolerant submerged plants 6, and the shallow beach 4 is planted with salt-tolerant emergent plants 5, and the shallow beach 4 is arranged alternately with the deep pool 3. The bottom of the deep pool 3 and the shallow beach 4 is paved with a sintered material layer 2 with porous adsorption and capable of promoting the expression of microbial functional genes, the top of the waterfall step 8 has a plurality of grooves, and aeration holes 81 are provided in the grooves for improving the reoxygenation capacity of the water body, and a filter wall 9 is provided on the outer side of the waterfall step 8 corresponding to the groove, and the filter wall 9 is made of a wire frame and filled with composite porous fillers.

[0019] In specific implementation, the emergent plants 5 are reeds, cattails or water plantains, with a planting density of 10-20 plants / m²; the submerged plants 6 are water chestnuts or foxtail algae, with a planting density of 20-30 plants / m²; the artificial aquatic plants 7 are made of polyester fibers and are used to attach biofilms to improve the removal rate of pollutants in low temperature seasons. The laying density is 3-5 plants / m², and the laying area is 20%-40% of the total area.

[0020] During specific implementation, the sintered material layer 2 is formed by mixing and sintering dehydrated aluminum sludge and reed straw. The dehydrated aluminum sludge and reed straw are mixed in a ratio of 1:2 and sintered at 350°C for 2 hours. It has the ability to adsorb pollutants and can also increase the niche width of the microbial community, promote the expression of functional genes related to pollutant degradation and the formation of biofilms, thereby improving the purification effect of high-salt, low-biodegradability, and slightly polluted water.

[0021] In specific implementation, the composite porous filler of the filter wall 9 is waste sponge iron and volcanic rock, and the ratio of waste sponge iron to volcanic rock is 1:1-1:2. Sponge iron releases ferrous ions through micro-corrosion, which can act as an electron donor to alleviate the adverse effects of low-carbon sources in the influent on denitrification, and volcanic rock has the ability to adsorb pollutants.

[0022] In specific implementation, the interior of the waterfall step 8 also has a channel connected to the aeration hole 81, and the channel is connected to the external aeration equipment.

[0023] The detailed connection means are well known in the art. The following mainly introduces the operation process, which includes the following steps: Influent regulation: high-salinity, low-biodegradability, slightly polluted water is introduced into the surface flow artificial wetland device to control the influent salinity below 3500 mg / L, BOD5 / COD CrThe hydraulic load is maintained at 0.1-0.3 m³ / (m²·d) and the number of operating sub-units is adjusted by pumping water according to the flow changes in the dry season to keep the hydraulic load at the optimal value of 0.2 m³ / (m²·d); In hierarchical treatment, sewage flows through the subunits of the curved flow unit in sequence. Each subunit is connected in series by a waterfall stepping stone. The curvature of the curved flow channel is 1.2-1.5. Shallows and deep pools are set alternately in the subunits. The water depth of the shallows is controlled at 0.3-1m, and salt-tolerant emergent plants are planted. The water depth of the deep pool is controlled at 1-2m, and salt-tolerant submerged plants are planted to promote the degradation of pollutants. The system flow rate is maintained at 0.5m / s through hydraulic regulation, which can promote biofilm growth and microbial community diversity. When the flow rate is insufficient, the water propeller is activated; Composite purification: when sewage flows through the waterfall stepping stone, it is naturally aerated and reoxygenated through the aeration holes in its grooves; the water flows through the filter wall, and the waste sponge iron and volcanic rock filled in the filter wall work together to release ferrous ions through micro-corrosion to promote denitrification, and at the same time adsorb pollutants. At the same time, the sintered material layer at the bottom enhances degradation through porous adsorption and microbial functional gene regulation.

[0024] Serial number Name of artificial wetland B / C Salinity (mg / L) 1 Surface flow artificial wetland in a certain area of Northwest China 0.38 984-2965 2 The present invention 0.25 998-2998 Table 1 Water quality characteristics of surface flow constructed wetland inlet Serial number name Influent ammonia nitrogen concentration (mg / L) Ammonia nitrogen removal rate (%) Influent total phosphorus concentration (mg / L) Total phosphorus removal rate (%) <![CDATA[Influent COD Cr Concentration (mg / L)]]> <![CDATA[COD Cr Removal rate (%)]]> 1 Surface flow artificial wetland in a certain area of Northwest China 0.43 51.5 0.21 52.2 37.4 10.8% 2 The present invention 5.06 90.5 0.5 62.0 51.2 59.3 Table 2 Comparison of water purification effects of surface flow artificial wetlands As shown in Table 1 and Table 2, this embodiment has a higher pollutant removal rate than a surface flow artificial wetland in the northwest region, especially in terms of COD Cr The effluent can meet the surface water Class IV standard.

[0025] The above description of the embodiments is to facilitate ordinary technicians in this technical field to understand and use the present invention. It is obvious that those familiar with the technology in this field can easily make various modifications to the embodiments and apply the general principles described herein to other embodiments without having to engage in creative work. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A surface flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water, characterized by: The invention comprises a curved flow channel unit, which is composed of several subunits connected in series through a waterfall step (8), each subunit comprising a supporting layer (1), a deep pool (3) and a shallow beach (4) on one side of the top of the supporting layer (1), and artificial aquatic plants (7) on the other side of the top thereof, wherein the deep pool (3) is planted with salt-tolerant submerged plants (6), and the shallow beach (4) is planted with salt-tolerant emergent plants (5), and a sintered material layer (2) having porous adsorption and capable of promoting the expression of microbial functional genes is laid on the bottom of the deep pool (3) and the shallow beach (4), the top of the waterfall step (8) has a plurality of grooves, and aeration holes (81) are provided in the grooves, and a filter wall (9) is provided on the outer side of the waterfall step (8) at the corresponding grooves, and the filter wall (9) is made of a frame made of iron wire and filled with composite porous fillers.

2. The surface flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water according to claim 1, characterized in that: The shallows (4) and the deep pools (3) are arranged alternately.

3. The surface flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water according to claim 1, characterized in that: The emergent plants (5) are reeds, cattails or water plantains, with a planting density of 10-20 plants / m²; the submerged plants (6) are water chestnuts or foxtail algae, with a planting density of 20-30 plants / m²; the artificial aquatic plants (7) are made of polyester fibers, with a laying density of 3-5 plants / m², and a laying area of 20%-40% of the total area.

4. The surface flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water according to claim 1, characterized in that: The sintered material layer (2) is formed by mixing dehydrated aluminum sludge and reed straw and sintering them.

5. The surface flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water according to claim 1, characterized in that: The composite porous filler of the filter wall (9) is waste sponge iron and volcanic rock, and the ratio of the waste sponge iron to the volcanic rock is 1:1-1:

2.

6. The surface flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water according to claim 1, characterized in that: The waterfall step (8) further comprises a channel inside thereof which is connected to the aeration hole (81), and the channel is connected to an external aeration device.

7. A method for operating a surface-flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water, applied to the surface-flow artificial wetland device for efficiently purifying high-salinity, low-biodegradability, slightly polluted water according to any one of claims 1 to 6, characterized in that: The following steps are involved: Influent regulation: high-salinity, low-biodegradability, slightly polluted water is introduced into the surface flow artificial wetland device to control the influent salinity below 3500 mg / L, BOD5 / COD Cr The hydraulic load is maintained at 0.1-0.3 m³ / (m²·d) and the number of operating sub-units is adjusted by pumping water according to the flow changes in the dry season to keep the hydraulic load at the optimal value of 0.2 m³ / (m²·d); In hierarchical treatment, sewage flows through the sub-units of the curved flow unit in sequence. Each sub-unit is connected in series by waterfall stepping stones. Shallows and deep pools are set alternately in the sub-units. Salt-tolerant emergent plants are planted in the shallows, and salt-tolerant submerged plants are planted in the deep pools to promote the degradation of pollutants. The system flow rate is maintained at 0.5m / s through hydraulic regulation. When the flow rate is insufficient, the water propeller is activated; Composite purification: when sewage flows through the waterfall stepping stone, it is naturally aerated and reoxygenated through the aeration holes in its grooves; the water flows through the filter wall, and the waste sponge iron and volcanic rock filled in the filter wall work together to release ferrous ions through micro-corrosion to promote denitrification, and at the same time adsorb pollutants. At the same time, the sintered material layer at the bottom enhances degradation through porous adsorption and microbial functional gene regulation.

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