Integrated ecological treatment device for soil remediation and sewage purification

Abstract

The invention discloses a soil remediation and sewage purification integrated ecological treatment device which comprises a vertical flow artificial wetland region, a horizontal subsurface flow artificial wetland region and an ecological purification region which are sequentially arranged in the water flow direction, so that soil remediation and sewage purification are organically integrated, sewage can be purified, heavy metal can be prevented from migrating to soil, and the soil remediation and sewage purification effects are improved. The composite filler in the vertical flow artificial wetland realizes resource utilization of the polluted soil, the composite filler in the horizontal subsurface flow artificial wetland removes multiple pollutants in a targeted manner, and intermittent aeration is matched to improve the microbial activity, so that efficient green treatment of sewage and soil is realized. Soil in-situ remediation and sewage pretreatment are achieved in the vertical flow artificial wetland, pollutants are deeply purified and prevented from leaking in the horizontal subsurface flow artificial wetland, deep nitrogen and phosphorus removal and heavy metal absorption are achieved at the tail end of the ecological purification area, the risk of secondary pollution can be effectively avoided, and it can be ensured that the effluent quality stably reaches the standard.

Description

Technical Field

[0001] This application relates to the technical field of ecological treatment, and in particular to an integrated ecological treatment device for soil remediation and wastewater purification. Background Technology

[0002] Currently, heavy metal pollution in soil and water bodies have become key issues restricting ecological and environmental governance. The two often influence each other and form a pollution chain. Soil contaminated with heavy metals is easily leached by rainwater, leading to water pollution. Polluted water bodies, in turn, further exacerbate the accumulation of heavy metals in the soil, posing a dual threat to the ecological environment and human health. Soil remediation and wastewater purification often adopt separate treatment models.

[0003] In the field of soil heavy metal remediation, current treatment methods mainly include three categories: physical remediation, chemical remediation, and bioremediation. Physical remediation, such as topsoil replacement, is costly, involves a large amount of engineering work, and is prone to damaging the soil structure; chemical remediation, such as chemical leaching, is fast-acting, but the use of chemical agents can easily cause secondary pollution and may also reduce soil fertility; bioremediation, such as phytoremediation, is environmentally friendly, but single bioremediation methods have long remediation cycles, relatively low efficiency, and limited effectiveness in remediating complex contaminated soils.

[0004] In the field of wastewater treatment, constructed wetlands are widely used due to their advantages such as being eco-friendly and having low operating costs. However, existing constructed wetlands mostly focus on a single wastewater treatment function. In addition, traditional constructed wetlands mostly use a single type of filler, which has a limited specific surface area and insufficient adsorption activity. It has a weak ability to adsorb and retain heavy metal ions in wastewater, making it difficult to achieve deep purification of pollutants.

[0005] Application content

[0006] This application aims to address, at least to some extent, the technical problems in the related art.

[0007] To achieve the above objectives, this application proposes an integrated ecological treatment device for soil remediation and wastewater purification, comprising a vertical flow constructed wetland, a horizontal subsurface flow constructed wetland, and an ecological purification zone arranged sequentially along the water flow direction. The vertical flow constructed wetland comprises, from bottom to top, a support layer, a first composite filler layer, and a first plant layer. The first composite filler layer comprises soil contaminated with heavy metals, zeolite, and biochar. A water collection pipe is located at the bottom of the vertical flow constructed wetland, and an aeration disc is located at the bottom of the first composite filler layer. The aeration disc is connected to an external aerator for supplying water to the first plant layer. Intermittent oxygen supply is provided at the bottom of the composite filler layer; the horizontal subsurface flow constructed wetland area is provided with an impermeable layer, a second composite filler layer and a second plant layer from bottom to top. The second composite filler layer includes limestone, slag and activated alumina. The water collection pipe is connected to the water outlet of the vertical flow constructed wetland area and the water inlet of the horizontal subsurface flow constructed wetland area respectively. The water flows horizontally through the second composite filler layer in a subsurface flow manner; the ecological purification area is an open water area. The ecological purification area is provided with a biological floating bed. The biological floating bed is planted with aquatic plants for deep nitrogen and phosphorus removal and absorption of heavy metals.

[0008] In addition, the application may also include the following additional technical features:

[0009] Specifically, the first plant layer is planted with one or more of reeds, cattails, and calamus, and the second plant layer is planted with one or more of canna lilies, irises, and rushes.

[0010] Specifically, in the vertical flow artificial wetland, the first composite filler layer is divided into three layers from top to bottom: the upper layer is a mixture of biochar and soil contaminated with heavy metals, the middle layer is a zeolite layer, and the lower layer is a mixture of zeolite and soil contaminated with heavy metals.

[0011] Specifically, the water collection pipe is equipped with a flow regulating valve, which is used to dynamically adjust the hydraulic residence time according to the water quality of the incoming water, so that the hydraulic residence time of the vertical flow artificial wetland is 6-12 hours and the hydraulic residence time of the horizontal subsurface flow artificial wetland is 12-24 hours.

[0012] Specifically, in the first composite filler layer, the volume mixing ratio of zeolite to biochar is 2:1, and in the second composite filler layer, the volume mixing ratio of limestone, slag, and activated alumina is 2:1:1.

[0013] Specifically, the bottom of the ecological purification zone is covered with artificial aquatic plants, which are made of biomimetic fiber material and are used to provide an attachment carrier for microorganisms in the water.

[0014] Specifically, the framework of the bio-floating bed is filled with a lightweight porous substrate, through which the roots of the aquatic plants grow and are suspended in the water.

[0015] Specifically, the supporting layer is laid in layers of pebbles and quartz sand, with the pebble layer at the bottom and the quartz sand layer at the top, and a geotextile isolation layer is provided between the pebble layer and the quartz sand layer.

[0016] Specifically, the impermeable layer is made of high-density polyethylene geomembrane, a bentonite waterproof layer is laid below the high-density polyethylene geomembrane, and a fine sand protective layer is laid on top of the high-density polyethylene geomembrane.

[0017] The beneficial effects of the integrated ecological treatment device for soil remediation and wastewater purification proposed in this application are as follows:

[0018] 1. Soil remediation and wastewater purification are organically integrated, which can not only purify wastewater and block the migration of heavy metals into the soil, but also remediate polluted soil in situ, forming an integrated governance system to curb the two-way pollution cycle from the source.

[0019] 2. Vertical flow constructed wetland composite fillers enable the resource utilization of contaminated soil, while horizontal subsurface flow constructed wetland composite fillers specifically remove multiple pollutants. Combined with intermittent aeration, they enhance microbial activity, solving the problem of low bioremediation efficiency and achieving efficient and green treatment of wastewater and soil.

[0020] 3. Vertical flow constructed wetlands enable in-situ soil remediation and wastewater pretreatment, while horizontal subsurface flow constructed wetlands deeply purify pollutants and prevent leakage. Ecological purification zones provide deep nitrogen and phosphorus removal and heavy metal absorption at the end of the process. Through multi-stage layer-by-layer control, the stability and reliability of the treatment are enhanced, effectively avoiding the risk of secondary pollution and ensuring that the effluent quality consistently meets standards. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0022] Figure 1 This is a schematic diagram of this application.

[0023] As shown in the figure: 1. Vertical flow artificial wetland area; 11. Support layer; 12. First composite packing layer; 13. First plant layer; 14. Water collection pipe; 15. Aeration disc; 16. Flow regulating valve; 2. Horizontal subsurface flow artificial wetland area; 21. Impermeable layer; 22. Second composite packing layer; 23. Second plant layer; 3. Ecological purification zone; 31. Aquatic plants; 32. Biological floating bed; 33. Artificial aquatic plants. Detailed Implementation

[0024] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "center", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation structure and operation. Therefore, they should not be construed as limitations on this application.

[0025] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "provided with," "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] The present application will now be described in further detail with reference to the accompanying drawings.

[0027] like Figure 1 As shown in the figure, an integrated ecological treatment device for soil remediation and wastewater purification according to an embodiment of this application includes a vertical flow constructed wetland 1, a horizontal subsurface flow constructed wetland 2 and an ecological purification zone 3 arranged sequentially along the water flow direction.

[0028] The vertical flow constructed wetland 1 is provided with a support layer 11, a first composite filler layer 12 and a first plant layer 13 from bottom to top. The first composite filler layer 12 includes soil contaminated with heavy metals, zeolite and biochar. A water collection pipe 14 is provided at the bottom of the vertical flow constructed wetland 1. An aeration disc 15 is provided at the bottom of the first composite filler layer 12. The aeration disc 15 is connected to an external aerator for intermittent oxygen supply to the bottom of the first composite filler layer 12.

[0029] It should be noted that the wastewater flows from top to bottom through the first plant layer 13, then permeates into the first composite filler layer 12, and finally undergoes pretreatment through the support layer 11. The vertical flow structure allows the water to permeate from top to bottom, achieving purification and soil remediation through the stratification of each layer of media. The support layer 11 provides stable support for the upper structure. The first plant layer 13 absorbs pollutants such as heavy metals, nitrogen, and phosphorus from the wastewater. The zeolite, with its numerous micropores and channels, provides ample adsorption sites, fixing free heavy metals in the zeolite lattice through ion exchange, thus reducing the heavy metal content in the soil. Biochar, through physical adsorption, quickly intercepts suspended organic matter and heavy metal particles in the soil, while also adsorbing odor substances in the soil.

[0030] The aeration disc 15 intermittently supplies oxygen to the bottom of the first composite packing layer 12. Through intermittent aeration and periodic oxygen supply, an alternating aerobic-anaerobic environment is formed in the packing layer. The aerobic stage promotes the degradation of organic matter and nitrification reaction, while the anaerobic stage is conducive to denitrification and nitrogen removal, thereby improving the overall treatment efficiency.

[0031] The horizontal subsurface flow constructed wetland area 2 is provided with an impermeable layer 21, a second composite filler layer 22 and a second plant layer 23 from bottom to top. The second composite filler layer 22 includes limestone, slag and activated alumina. The water collection pipe 14 is connected to the water outlet of the vertical flow constructed wetland area 1 and the water inlet of the horizontal subsurface flow constructed wetland area 2 respectively. The water flows horizontally through the second composite filler layer 22 in a subsurface flow manner.

[0032] It should be noted that the horizontal subsurface flow structure allows water to permeate horizontally within the packing layer, extending the hydraulic residence time and preventing surface evaporation and odor diffusion. The impermeable layer 21 prevents wastewater from seeping into and polluting groundwater during treatment. In the second composite packing layer 22, limestone can adjust the pH value of the influent and remove some phosphorus through calcium carbonate precipitation. Slag, with its porosity and surface activity, adsorbs heavy metals, suspended solids, and organic matter. Activated alumina has a strong selective adsorption capacity for phosphorus and can deeply remove phosphates from the water. The subsurface flow method allows the water to completely submerge the packing, forming a stable anaerobic-anoxic environment, which is conducive to the growth and reproduction of denitrifying bacteria and phosphorus-accumulating bacteria. The roots of the second plant layer 23 can penetrate deep into the second composite packing layer 22, forming a dense root network, further intercepting trace amounts of heavy metals, phosphorus, and organic matter remaining in the wastewater after treatment by the packing layer.

[0033] Ecological purification zone 3 is an open water area. A biological floating bed 32 is set up in ecological purification zone 3, and aquatic plants 31 for deep denitrification, phosphorus removal and heavy metal absorption are planted on the biological floating bed 32.

[0034] It should be noted that the water discharged from the second composite filler layer 22 enters the ecological purification zone 3. The open water area can increase the dissolved oxygen content of the water body through atmospheric reoxygenation, promote the aerobic metabolism of microorganisms in the water, and further purify the water quality through physical processes such as sedimentation and volatilization of the water body itself. The biological floating bed 32 fixes aquatic plants through floating carriers. The plant roots penetrate deep into the water and can directly absorb nutrients such as nitrogen and phosphorus in the water body. At the same time, the roots adsorb heavy metals and suspended solids, and the biofilm formed on the surface of the roots can degrade residual organic matter in the water. The photosynthesis of aquatic plants 31 can also increase the dissolved oxygen in the water body, inhibit the growth of harmful algae, and maintain the ecological balance of the water body.

[0035] Specifically, during actual operation, staff turn on the aerator to check the uniformity of aeration, adjust the flow regulating valve 16, set the hydraulic retention time of vertical flow artificial wetland 1 (6-12h) and horizontal subsurface flow artificial wetland 2 (12-24h), and introduce the sewage to be treated into vertical flow artificial wetland 1, where it undergoes preliminary pretreatment through the first plant layer 13, the first composite filler layer 12, and the support layer 11.

[0036] Water flows from top to bottom, the first plant layer 13 absorbs pollutants to assist in purification, the first composite filler layer 12 (zeolite, biochar, contaminated soil) adsorbs heavy metals and organic matter, and simultaneously repairs the soil, the aeration disc 15 intermittently supplies oxygen, forming an alternating aerobic-anaerobic environment, improving the pollutant degradation efficiency, and the treated wastewater is introduced into the horizontal subsurface flow artificial wetland 2 through the collection pipe 14.

[0037] Wastewater flows horizontally through the second composite filler layer 22. The impermeable layer 21 prevents wastewater from seeping down. The roots of the second plant layer 23 intercept trace pollutants, improving water purity. Wastewater overflows into the ecological purification zone 3. The biological floating bed 32 and the artificial aquatic plants at the bottom work together to degrade residual pollutants and promote the sedimentation of suspended solids. After ecological stabilization, the wastewater meets the discharge standards or is recycled.

[0038] In one embodiment of this application, as shown in the figure, the first plant layer 13 is planted with one or more of reeds, cattails, and calamus, and the second plant layer 23 is planted with one or more of canna lilies, irises, and rushes.

[0039] Specifically, the first plant layer 13 selects emergent plants with strong pollution tolerance and well-developed root systems, such as reeds, cattails, and calamus. Their roots can penetrate deep into the first composite filler layer, which can not only absorb pollutants such as heavy metals, nitrogen, and phosphorus in the soil and sewage, but also secrete root secretions to promote microbial activity. At the same time, the root penetration can enhance the permeability of the filler layer, which is conducive to water flow and gas diffusion.

[0040] The second plant layer 23 is designed for the anaerobic-anoxic environment and low-concentration pollutant residues of the horizontal subsurface flow artificial wetland 2. Emergent plants such as canna lilies, irises, and rushes are selected to be tolerant of subsurface flow and have high purification efficiency. Their roots can form a dense root network in the subsurface flow filler layer, which can enhance the interception and transformation of phosphorus, trace heavy metals and organic matter, while adapting to the relatively stable hydraulic environment.

[0041] In one embodiment of this application, such as Figure 1 As shown, in the vertical flow artificial wetland 1, the first composite filler layer 12 is divided into three layers from top to bottom: the upper layer is a mixture of biochar and soil contaminated by heavy metals, the middle layer is a zeolite layer, and the lower layer is a mixture of zeolite and soil contaminated by heavy metals.

[0042] It should be noted that the first composite filler layer 12 adopts a layered design to achieve gradient interception of pollutants and soil remediation. The high adsorption activity of biochar in the upper mixed layer can preferentially intercept suspended organic matter and some heavy metals in the water flow, while adsorbing odor substances in the sewage. Soil contaminated with heavy metals can intercept newly introduced heavy metals through surface adsorption and ion exchange, thereby achieving self-remediation while reducing the concentration of heavy metals in sewage.

[0043] The middle zeolite layer, with its uniform porous structure and excellent ion exchange performance, effectively removes dissolved heavy metals and ammonia nitrogen from the water flow, forming the core purification layer.

[0044] The lower mixed layer serves both a supporting function and a deep trapping function. Zeolite can further adsorb residual heavy metals, and the soil contaminated by heavy metals will continue to undergo a remediation reaction. At the same time, it provides stable support for the upper structure and prevents the loss of filler.

[0045] In one embodiment of this application, such as Figure 1 As shown, the water collection pipe 14 is equipped with a flow regulating valve 16, which is used to dynamically adjust the hydraulic residence time according to the water quality of the influent, so that the hydraulic residence time of the vertical flow artificial wetland area 1 is 6-12 hours and the hydraulic residence time of the horizontal subsurface flow artificial wetland area 2 is 12-24 hours.

[0046] It should be noted that the flow regulating valve 16 is a solenoid valve. The hydraulic residence time is a key parameter affecting the treatment effect of constructed wetlands. The flow regulating valve 16 can control the water flow rate by adjusting the valve opening, thereby adjusting the hydraulic residence time of each treatment area. When the concentration of pollutants in the influent is high, the valve opening is reduced to prolong the hydraulic residence time, ensuring that the pollutants have sufficient time to be removed through physical, chemical, and biological processes.

[0047] When the concentration of pollutants in the influent is low, the valve opening is increased to shorten the hydraulic retention time, improve treatment efficiency, and avoid energy and space waste. The set retention time range has been optimized to meet the treatment needs of most domestic sewage, agricultural non-point source sewage, and wastewater contaminated with heavy metals.

[0048] In one embodiment of this application, such as Figure 1 As shown, in the first composite packing layer 12, the volume mixing ratio of zeolite to biochar is 2:1, and in the second composite packing layer 22, the volume mixing ratio of limestone, slag and activated alumina is 2:1:1.

[0049] It should be noted that in the first composite packing layer 12, the volume ratio of zeolite to biochar is 2:1, which can balance the ion exchange and adsorption functions. Zeolite, as the main packing material, can efficiently remove heavy metals and ammonia nitrogen through ion exchange, while biochar can supplement the adsorption of organic matter and some recalcitrant heavy metals, and at the same time provide an attachment carrier for microorganisms.

[0050] In the second composite packing layer 22, the volume ratio of limestone, slag and activated alumina is 2:1:1. Limestone, as the main component, can effectively regulate the pH value of the influent and remove some phosphorus through sedimentation. Slag adsorbs suspended solids and heavy metals through its porous structure, while activated alumina specifically removes phosphorus at a deep level. The three components work together to achieve multiple objectives, including pH control, heavy metal removal and deep phosphorus purification.

[0051] In one embodiment of this application, such as Figure 1 As shown, artificial aquatic plants 33 are laid at the bottom of the ecological purification zone 3. The artificial aquatic plants 33 are made of biomimetic fiber material and are used to provide an attachment carrier for microorganisms in the water.

[0052] Specifically, Artificial Aquatic Plant 33 uses biomimetic fiber material with a rich microporous structure on its surface and strong hydrophilicity. It can simulate the growth form and function of natural aquatic plants, providing a large number of attachment carriers for heterotrophic bacteria, nitrifying bacteria, denitrifying bacteria and other microorganisms in the water, forming a dense biofilm.

[0053] Microorganisms in biofilms can degrade pollutants such as residual organic matter and ammonia nitrogen in water through metabolism. At the same time, the presence of artificial aquatic plants can slow down the water flow and promote the sedimentation of suspended solids in the water, further improving the water purification effect. In addition, artificial aquatic plants do not rot and deteriorate like natural aquatic plants and can play a stable role for a long time.

[0054] In one embodiment of this application, such as Figure 1 As shown, the framework of the bio-floating bed 32 is filled with a lightweight porous substrate, and the roots of the aquatic plants 31 grow through the substrate and are suspended in the water.

[0055] It should be noted that the lightweight porous matrix within the bio-floating bed frame has the characteristics of low density and high porosity, which allows the floating bed to float stably on the water surface. At the same time, it provides a stable growth carrier for aquatic plants, preventing them from falling over. The roots of the aquatic plants 31 penetrate the matrix and are suspended in the water, which can increase the contact area between the roots and the water, allowing for more complete absorption of nutrients such as nitrogen and phosphorus from the water. Meanwhile, the biofilm formed on the root surface can degrade organic matter and trace pollutants, and the porous matrix itself can also adsorb some pollutants and provide an attachment carrier for microorganisms, forming a synergistic purification system with plant roots and aquatic microorganisms.

[0056] In one embodiment of this application, such as Figure 1 As shown, the support layer 11 is laid in layers of pebbles and quartz sand, with the pebble layer at the bottom and the quartz sand layer at the top, and a geotextile isolation layer between the pebble layer and the quartz sand layer.

[0057] It should be noted that the lower pebble layer (with larger particle size) provides stable support for the first composite filler layer 12, while intercepting larger suspended solids and impurities in the water flow to prevent them from entering the filler layer and causing blockage; the upper quartz sand layer (with smaller particle size) can further filter fine suspended solids in the water, improve the quality of the influent water, and lay the foundation for the purification effect of the first composite filler layer 12; the middle geotextile isolation layer can prevent the pebbles and quartz sand from mixing, and at the same time prevent the upper filler particles from leaking into the support layer.

[0058] In one embodiment of this application, such as Figure 1 As shown, the impermeable layer 21 is made of high-density polyethylene geomembrane, a bentonite waterproof layer is laid below the high-density polyethylene geomembrane, and a fine sand protective layer is laid above the high-density polyethylene geomembrane.

[0059] It should be noted that high-density polyethylene geomembrane has excellent seepage prevention performance and can effectively block sewage infiltration; the bentonite waterproof layer below is an auxiliary seepage prevention layer. After the bentonite expands when it comes into contact with water, it can form a dense seepage barrier, fill any minor damage to the geomembrane, and improve the overall seepage prevention effect; the fine sand protective layer above can prevent sharp particles (such as slag and limestone fragments) in the second composite filler layer from scratching or puncturing the geomembrane, while buffering the impact of water flow and filler on the geomembrane.

[0060] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0061] The present application and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present application. The actual structure is not limited to this. In conclusion, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the present application, such design should fall within the protection scope of the present application.

Claims

1. An integrated ecological treatment device for soil remediation and wastewater purification, characterized in that, It includes a vertical flow constructed wetland area (1), a horizontal subsurface flow constructed wetland area (2), and an ecological purification area (3) arranged sequentially along the water flow direction. The vertical flow constructed wetland area (1) is provided with a support layer (11), a first composite filler layer (12) and a first plant layer (13) from bottom to top. The first composite filler layer (12) includes soil contaminated with heavy metals, zeolite and biochar. A water collection pipe (14) is provided at the bottom of the vertical flow constructed wetland area (1). An aeration disc (15) is provided at the bottom of the first composite filler layer (12). The aeration disc (15) is connected to an external aerator and is used to intermittently supply oxygen to the bottom of the first composite filler layer (12). The horizontal subsurface flow artificial wetland (2) is provided with an impermeable layer (21), a second composite filler layer (22), and a second plant layer (23) from bottom to top. The second composite filler layer (22) includes limestone, slag, and activated alumina. The water collection pipe (14) is connected to the water outlet of the vertical flow artificial wetland (1) and the water inlet of the horizontal subsurface flow artificial wetland (2) respectively. The water flows horizontally through the second composite filler layer (22) in a subsurface flow manner. The ecological purification zone (3) is an open water area, and a biological floating bed (32) is set up in the ecological purification zone (3). Aquatic plants (31) for deep denitrification, phosphorus removal and heavy metal absorption are planted on the biological floating bed (32).

2. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, The first plant layer (13) is planted with one or more of reeds, cattails, and calamus, and the second plant layer (23) is planted with one or more of canna lilies, irises, and rushes.

3. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, In the vertical flow artificial wetland area (1), the first composite filler layer (12) is divided into three layers from top to bottom: the upper layer is a mixture of biochar and soil contaminated by heavy metals, the middle layer is a zeolite layer, and the lower layer is a mixture of zeolite and soil contaminated by heavy metals.

4. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, The water collection pipe (14) is equipped with a flow regulating valve (16) for dynamically adjusting the hydraulic residence time according to the water quality of the incoming water, so that the hydraulic residence time of the vertical flow artificial wetland area (1) is 6-12 hours and the hydraulic residence time of the horizontal subsurface flow artificial wetland area (2) is 12-24 hours.

5. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, In the first composite filler layer (12), the volume mixing ratio of zeolite and biochar is 2:1, and in the second composite filler layer (22), the volume mixing ratio of limestone, slag and activated alumina is 2:1:

1.

6. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, Artificial aquatic plants (33) are laid at the bottom of the ecological purification zone (3). The artificial aquatic plants (33) are made of biomimetic fiber material and are used to provide an attachment carrier for microorganisms in the water.

7. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, The framework of the bio-floating bed (32) is filled with a lightweight porous substrate, through which the roots of the aquatic plant (31) grow and are suspended in the water.

8. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, The supporting layer (11) is laid in layers of pebbles and quartz sand, with the pebble layer at the bottom and the quartz sand layer at the top, and a geotextile isolation layer between the pebble layer and the quartz sand layer.

9. The integrated ecological treatment device for soil remediation and wastewater purification according to claim 1, characterized in that, The impermeable layer (21) is made of high-density polyethylene geomembrane. Bentonite waterproofing layer is laid below the high-density polyethylene geomembrane, and fine sand protective layer is laid above the high-density polyethylene geomembrane.

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