Carbon source slow-release bed for purification of tailwater wetlands
By constructing a slow-release carbon source bed using the rhizomes of moso bamboo and reed, combined with emergent plants and casing piles for fixation, the problems of easy material damage, large land occupation, unstable treatment and high energy consumption in tailwater wetland purification are solved, achieving environmentally friendly and efficient water purification and landscape effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUXI TAIHU LAKE REMEDIATION CO LTD
- Filing Date
- 2025-06-06
- Publication Date
- 2026-06-16
AI Technical Summary
Existing wastewater wetland purification technologies suffer from problems such as easily damaged materials, large land area requirements, unstable treatment effects, high energy consumption, and frequent maintenance. There is an urgent need for a more flexible and environmentally friendly carbon source slow-release bed.
Using the rhizomes of moso bamboo and reed as carrier substrates, combined with emergent plants and casing piles for fixation, a carbon source slow-release bed is formed. The water quality is purified through the absorption of the roots of emergent plants and the metabolism of microorganisms, and it adapts to changes in water level.
It achieves environmentally friendly and stable water purification, reduces material damage and maintenance costs, improves nitrogen and phosphorus removal efficiency, adapts to water level changes, and maintains the aesthetic appeal of the landscape.
Smart Images
Figure CN224362636U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of ecological restoration technology, specifically a carbon source slow-release bed for tailwater wetland purification. Background Technology
[0002] Existing technologies for wastewater wetland purification mainly include ecological floating island technology, constructed wetland technology, and microbial treatment technology.
[0003] (1) Ecological floating island technology
[0004] Ecological floating islands utilize the principle of buoyancy to grow plants in water. The plants absorb nutrients and pollutants from the water through their roots, while simultaneously providing oxygen and promoting the reproduction of aerobic microorganisms, thus purifying the water. This technology not only removes suspended solids, organic matter, and nutrients such as nitrogen and phosphorus from the water, but also increases the water body's self-purification capacity and improves water quality.
[0005] (2) Constructed wetland technology
[0006] Constructed wetlands are artificial ecosystems that mimic natural wetlands, purifying water through physical, chemical, and biological processes. They typically consist of substrates, plants, and aquatic animals, removing pollutants from the water through processes such as filtration, adsorption, sedimentation, and plant uptake. Constructed wetlands can be categorized into various types, including surface flow wetlands, subsurface flow wetlands, and vertical flow wetlands, to suit different water purification needs.
[0007] (3) Microbial treatment technology
[0008] Microbial treatment technology utilizes specific microbial communities to decompose pollutants such as organic matter and ammonia nitrogen in water. By selecting and cultivating highly efficient microbial communities, a stable ecosystem can be formed in wetland systems, effectively removing pollutants from the water. This technology has advantages such as good treatment effect and low operating cost, and is suitable for water purification projects of various sizes.
[0009] However, all three of these technologies have their shortcomings:
[0010] (1) Ecological floating island technology
[0011] Material durability issues: Early eco-friendly floating islands mostly used foam or frame structures, which are prone to damage or disintegration, leading to secondary pollution. Some materials, such as foam, constitute white pollution and do not meet environmental protection requirements, and have been gradually phased out. New materials, such as PE products, have overcome some of the shortcomings, but their modular design is unstable, and the edges are not adequately designed to withstand wave abrasion, limiting their large-scale application.
[0012] Plant growth limitations: Incorrect media selection can restrict plant growth, leading to sparse vegetation and consequently affecting purification efficiency. Plant growth slows down or even dies in winter, significantly reducing the purification effectiveness of the floating islands during this season.
[0013] Addressing water level fluctuations: Generally, ecological floating islands are fixed by suspending heavy objects over steel pipe piles. However, as the water level fluctuates, the ecological floating island may be exposed above the water surface or shift in position, affecting the overall effect.
[0014] Limitations in purification capacity: Ecological floating islands are not very effective in treating severely polluted water bodies and struggle to handle high concentrations of pollutants. The purification capacity of floating islands is selectively affected by water quality and the surrounding environment; if improperly installed, they may lose their water purification function or even damage the landscape.
[0015] (2) Constructed wetland technology
[0016] Large land area required: Compared with traditional sewage treatment plants, constructed wetlands require a larger land area, which increases land costs.
[0017] Siltation and saturation issues: After long-term operation, a large amount of nutrients and microorganisms may accumulate in constructed wetlands, leading to siltation and saturation, which reduces hydraulic conductivity and treatment efficiency.
[0018] Fluctuations in treatment effectiveness: The removal effectiveness of constructed wetlands for pollutants is affected by the season and plant growth cycle. The initial removal rate may be unstable and it takes a long time to reach a stable operating state.
[0019] (3) Microbial treatment technology
[0020] Processing capacity limitations: Microbial treatment technology has a relatively small processing unit capacity and may not be suitable for large-scale water purification projects.
[0021] Energy consumption and cost issues: Microbial treatment technology consumes a lot of energy and requires a large amount of carbon source, which increases operating costs.
[0022] In summary, constructed wetlands occupy a large area and have a monotonous landscape; ecological floating islands are prone to aesthetic damage due to material breakage; traditional devices require frequent maintenance (such as cleaning silt and replenishing carbon sources), and there is an urgent need for a more flexible and environmentally friendly carbon source slow-release bed to supplement and replace the aforementioned wastewater wetland purification technologies. Utility Model Content
[0023] The problem to be solved is to provide a more flexible and environmentally friendly carbon source slow-release bed.
[0024] To achieve the above objectives, this utility model provides the following technical solution: a carbon source slow-release bed for wastewater wetland purification, comprising a carrier matrix, the carrier matrix comprising multiple first horizontal bamboo, multiple second horizontal bamboo, and several longitudinal substrates vertically arranged between the first horizontal bamboo and the second horizontal bamboo, the first horizontal bamboo and the second horizontal bamboo being arranged in parallel at intervals, and the several longitudinal substrates being arranged side by side; the longitudinal substrate comprising longitudinal bamboo tubes, longitudinal reed rhizomes, and binding straps, the longitudinal reed rhizomes being bound to the surface of the longitudinal bamboo tubes to form a carbon source slow-release structure; also comprising emergent plants planted on the carrier matrix; the longitudinal substrate being connected to the bottom of the pool through casing piles and floating on the water surface.
[0025] Furthermore, the casing pile includes a fixed pile and a movable pile. The fixed pile is buried at a predetermined depth at the bottom of the pool, and the movable pile is fitted inside the fixed pile.
[0026] Furthermore, the longitudinal bamboo tube has a diameter of 10cm and a length of 2m, and the longitudinal reed rhizomes are fixed along the circumference of the longitudinal bamboo tube by binding straps.
[0027] Furthermore, emergent plants include iris, variegated onion, and evergreen iris, with a planting density of 36 clumps per square meter.
[0028] Furthermore, the ratio of emergent plants planted is iris: variegated water onion: evergreen iris = 3:4:3.
[0029] Furthermore, the fixed piles should be buried at a depth of no less than 1 meter into the bottom of the pool.
[0030] Furthermore, the total dimensions of the carrier matrix are 2m in length and 1.5m in width.
[0031] Compared with existing technologies, this utility model provides a carbon source slow-release bed for tailwater wetland purification, which has the following beneficial effects: The carrier matrix used in this utility model is ecological and environmentally friendly, using natural materials (bamboo and reed rhizomes) as the carrier matrix, avoiding secondary pollution and conforming to the concept of sustainable development. It also solves the problem of resource utilization of harvested reeds; the longitudinal reed rhizomes can serve as a slowly released carbon source for microorganisms on the roots of emergent plants, reducing costs. Furthermore, the combination of emergent plants and root microorganisms significantly improves the removal efficiency of pollutants such as nitrogen and phosphorus in water purification. The casing pile fixing method not only allows the carbon source slow-release bed to flexibly respond to water level changes but also enhances the overall aesthetics. The bamboo carrier matrix combined with emergent plants forms a natural landscape; the slow-release carbon source and casing pile design reduce human intervention and lower maintenance costs. Attached Figure Description
[0032] Figure 1 This is a schematic diagram illustrating the use of this utility model;
[0033] Figure 2 This is a schematic diagram of the casing pile installation of this utility model;
[0034] Figure 3 for Figure 2 Enlarged view of point A in the middle;
[0035] Figure 4 This is the front view of the present invention;
[0036] Figure 5 for Figure 4 Top view;
[0037] Figure 6 This is an enlarged schematic diagram of the longitudinal matrix involved in this utility model;
[0038] Explanation of reference numerals in the attached drawings: 1. Pool bottom; 2. Sleeve pile; 21. Fixed pile; 211. Limiting nut; 22. Movable pile; 221. Limiting plate; 3. Carrier substrate; 31. First transverse bamboo; 32. Second transverse bamboo; 33. Longitudinal substrate; 34. Longitudinal bamboo tube; 35. Longitudinal reed rhizome; 36. Binding strap; 4. Emergent plant; 41. Emergent plant root system. Detailed Implementation
[0039] The technical solutions of the present utility model will now be described with reference to the accompanying drawings in the embodiments of the present utility model:
[0040] To address the problems in the background technology, this utility model uses the rhizomes of moso bamboo and reed as the carrier substrate for the carbon source slow-release bed. This approach is not only environmentally friendly but also solves the problem of resource utilization after reed harvesting. Selected emergent plants are planted on the carbon source slow-release bed, purifying the water through their root systems. Furthermore, the roots of these emergent plants, acting as a carrier, provide a favorable living environment for microorganisms. The metabolic activities of these microorganisms can also purify pollutants such as nitrogen and phosphorus in the water. Simultaneously, reed can slowly provide a carbon source for the microorganisms, eliminating the need for additional carbon sources, thus saving costs and solving the problem of reed resource utilization. Finally, the entire device is fixed using casing piles, allowing the height to be adjusted according to changes in water level, resulting in a good landscape effect.
[0041] As shown in the figure, a carbon source slow-release bed for wastewater wetland purification includes a carrier matrix 3. The carrier matrix 3 comprises multiple first horizontal bamboo 31s, multiple second horizontal bamboo 32s, and a longitudinal matrix 33. The first horizontal bamboo 31s and second horizontal bamboo 32s are arranged in parallel layers with intervals. The first horizontal bamboo 31s and second horizontal bamboo 32s reinforce the bamboo raft structure of the longitudinal matrix 33, preventing it from falling apart and ensuring overall stability. Several parallel longitudinal matrix 33s are vertically arranged between the first horizontal bamboo 31s and second horizontal bamboo 32s. The longitudinal matrix 33 includes longitudinal bamboo tubes 34, longitudinal reed rhizomes 35, and binding straps 36. The longitudinal reed rhizomes 35 are bound to the surface of the longitudinal bamboo tubes 34 to form a carbon source slow-release structure. The binding straps 36 use nylon ropes to fix the longitudinal reed rhizomes 35 to the longitudinal bamboo tubes 34. The nylon ropes are corrosion-resistant and tensile-resistant, ensuring that the carrier matrix does not fail during long-term underwater use and enhancing structural durability. The longitudinal bamboo tubes 34 provide structural support to fix the reed rhizomes, forming a carbon source slow-release carrier. The longitudinal rhizomes 35 of *Arundinaria salsa* slowly release carbon sources, providing continuous nutrition for microbial metabolism and reducing operating costs. Emergent plants 4 are planted on the carrier substrate 3. Their roots penetrate the substrate 3 and extend into the water, working with aquatic microorganisms to purify the water. The roots 41 absorb pollutants such as nitrogen and phosphorus from the water, directly purifying it. Microorganisms accumulate on the surface of the roots 41, forming a biofilm that decomposes organic matter and ammonia nitrogen through metabolic activity. The longitudinal substrate 33 is connected to the pool bottom 1 via casing piles 2 and floats on the water surface.
[0042] The casing pile 2 includes a fixed pile 21 and a movable pile 22. The fixed pile 21 is buried at a preset depth in the bottom of the pool 1. The movable pile 22 is fitted inside the fixed pile 21 to adjust its height and adapt to water level fluctuations. The fixed pile 21 provides anchoring force in the pool bottom to prevent the device from drifting. The movable pile 22 is fitted inside the fixed pile 21. The top of the fixed pile 21 is provided with no fewer than two limiting nuts 211, and the bottom of the movable pile 22 is provided with a limiting plate 221. The outer diameter of the limiting plate 221 is smaller than the inner diameter of the movable pile 22 to ensure that the limiting plate 221 moves up and down with the movable pile 22. The outer diameter of the limiting plate 221 is larger than the distance between the two corresponding limiting nuts 211. The limiting plate 221 can only move to below the limiting nuts 211 at most. The limiting nuts 211 limit the limiting plate 221. The height is adjusted with the rise and fall of the water level to maintain the effective immersion depth of the device. The bottom of the pool 1 serves as the installation foundation for the device, ensuring that the casing pile 2 is fixed and stable and adaptable to different water depth environments.
[0043] The embodiment is as follows: The carrier matrix 3 includes a first transverse bamboo 31, a second transverse bamboo 32, and a longitudinal matrix 33; the longitudinal matrix 33 is composed of longitudinal bamboo tubes 34, longitudinal reed rhizomes 35, and binding straps 36; as shown Figure 5As shown, the total length of a single carrier substrate 3 is 2m and the width is 1.5m. During the production process, firstly, longitudinal bamboo tubes 34 with a diameter of 10cm and a length of 2m are tied around the circumference with a 10mm diameter binding strap 36 using longitudinal reed rhizomes 35. The binding strap 36 is made of nylon rope. Then, 15 longitudinal bamboo tubes 34 with a length of 2m and a diameter of 10cm, which are tied with longitudinal reed rhizomes 35, are tied together and fixed in a row with 10mm diameter nylon rope, with a binding every 0.4m. On the horizontal direction of the tied bamboo row, at an average interval of 0.5m, the first horizontal bamboo 31 and the second horizontal bamboo 32 with a diameter of 5cm are used to make two layers of horizontal fixation.
[0044] Emergent plants 4 are planted on carrier substrate 3. Emergent plants 4 are selected from varieties that are evergreen, cold-resistant, have well-developed root systems and good purification effects. They generally include sweet flag, variegated water onion, and evergreen iris. Emergent plants 4 are more than 50cm tall and the planting density is 36 clumps / square meter. The planting ratio is sweet flag: variegated water onion: evergreen iris = 3:4:3.
[0045] like Figure 1 , 2 As shown, the device is fixed using casing piles 2, which include fixed piles 21 and movable piles 22. The top of the movable pile 22 penetrates the carrier matrix 3 and is fixed to it. The fixed pile 21 uses a hot-dip galvanized steel pipe pile as the outer pipe, with parameters DN50mm, wall thickness 3.5mm, and a burial depth to the bottom of the pool 1 of not less than H, where H is 1 meter. The length of the fixed pile 21 is adjusted according to the actual water depth. The bottom of the movable pile 22 is fitted inside the fixed pile 21 as a movable inner pipe, with parameters DN25mm, wall thickness 3mm, and an inner pipe length of 1500mm. The carbon source slow-release bed is secured with a 3mm diameter rope. The length of the movable pile 22 inside the fixed pile 21 is H1, where H1 is 1200mm. The length of the movable pile 22 extending out of the fixed pile 21 is H2, where H2 is 300mm. The length of the fixed pile 21 protruding from the bottom of the pool is H3, which is designed according to the water depth. In the design, the top of the fixed pile 21 is below the water level, and the top of the movable pile 22 is above the water level. Figure 3 As shown, during installation, first place the end of the movable pile 22 with the limiting plate 221 into the fixed pile 21, and then install the limiting nut 211 on the top of the fixed pile 21 to limit the limiting plate 221.
[0046] This technology was applied to the Taihu Lake sludge dewatering wetland project. A cutter suction hopper transports sludge from the bottom of Taihu Lake to the ship's hold, where PAC (3‰) and PAM are added to flocculate suspended solids (SS). The sludge-water mixture is then transported to a plate and frame filter press for dewatering. The sludge cake is transported off-site for landfill, and the filtered water is pumped to the tailwater wetland for treatment before being discharged. The tailwater wetland is mainly divided into four treatment units: influent → sedimentation tank → AO biological treatment tank → surface flow wetland → subsurface flow wetland → effluent. The carbon source slow-release bed with the above technical parameters is applied to the sedimentation tank, and the purification effects are as follows: the reduction rates of ammonia nitrogen, total nitrogen, total phosphorus, and SS are 30%, 46%, 33%, 17%, and 40%, respectively.
[0047] category Chemical oxygen demand ammonia nitrogen Total nitrogen Total phosphorus SS Incoming water parameters (mg / L) 50 6.5 12 0.3 50 Effluent parameters (mg / L) from sedimentation tanks without carbon source slow-release beds 41 6.3 11 0.3 40 Effluent parameters (mg / L) of sedimentation tanks using carbon source slow-release beds 65 3.5 8 0.25 30 Reduction rate (%) / 46 33 17 40
[0048] Furthermore, it reduces the amount of carbon source added to the subsequent AO biological treatment tank. Microorganisms in the biological treatment tank need carbon sources to maintain their life activities and metabolic processes. The slow-release bed carbon source can provide microorganisms with the necessary energy and nutrients, promote their growth and reproduction, thereby improving the treatment efficiency and stability of the biological treatment system, and can significantly improve denitrification efficiency. The supplementation of carbon source can promote the growth of heterotrophic bacteria, balance the bacterial community, effectively utilize the dominant beneficial colonies in the water to decompose harmful substances such as ammonia nitrogen and nitrite, while inhibiting the growth of harmful bacteria and reducing the probability of pathogenic outbreaks.
[0049] This invention utilizes the rhizomes of moso bamboo and reed to construct a slow-release carbon source bed, combined with emergent plants and a casing pile fixing device, to form a highly efficient and stable tailwater wetland purification system. The longitudinal reed rhizomes serve as a slow-release carbon source, continuously supporting microbial metabolism; the emergent plant roots adsorb pollutants and enrich microorganisms, achieving synergistic removal of nitrogen and phosphorus. The casing pile design ensures the device adapts to water level changes, avoiding the displacement problem of traditional floating islands. Practical application shows that this device achieves a 46% reduction in ammonia nitrogen, 33% in total nitrogen, and 17% in total phosphorus in sedimentation tanks, a 40% reduction in suspended solids, and a reduction in the amount of carbon source added for subsequent biochemical treatment. The overall solution combines ecological, economic, and aesthetic benefits, providing an innovative technological path for tailwater wetland purification.
[0050] The above embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.
Claims
1. A carbon source slow-release bed for wastewater wetland purification, characterized in that: The carrier substrate (3) includes multiple first horizontal bamboo (31), multiple second horizontal bamboo (32) and several longitudinal substrates (33) vertically arranged between the first horizontal bamboo (31) and the second horizontal bamboo (32). The first horizontal bamboo (31) and the second horizontal bamboo (32) are arranged in parallel with intervals, and the several longitudinal substrates (33) are arranged side by side. The longitudinal substrate (33) includes longitudinal bamboo tubes (34), longitudinal reed rhizomes (35) and binding straps (36). The longitudinal reed rhizomes (35) are bound to the surface of the longitudinal bamboo tubes (34) to form a carbon source slow-release structure. It also includes emergent plants (4) planted on the carrier substrate (3). The longitudinal substrate (33) is connected to the bottom of the pool (1) through the casing pile (2) and floats on the water surface.
2. The carbon source slow-release bed for tailwater wetland purification according to claim 1, characterized in that: The casing pile (2) includes a fixed pile (21) and a movable pile (22). The fixed pile (21) is buried at a preset depth in the bottom of the pool (1), and the movable pile (22) is fitted inside the fixed pile (21).
3. The carbon source slow-release bed for tailwater wetland purification according to claim 1, characterized in that: The longitudinal bamboo tube (34) has a diameter of 10cm and a length of 2m. The longitudinal reed rhizome (35) is fixed along the circumference of the longitudinal bamboo tube (34) by a binding strap (36).
4. The carbon source slow-release bed for tailwater wetland purification according to claim 1, characterized in that: Emergent plants (4) include iris, variegated onion and evergreen iris, with a planting density of 36 clumps / square meter.
5. The carbon source slow-release bed for tailwater wetland purification according to claim 4, characterized in that: The planting ratio of emergent plants (4) is 3:4:3:Iris tectorum: variegated water onion: evergreen iris.
6. The carbon source slow-release bed for tailwater wetland purification according to claim 2, characterized in that: The fixed pile (21) is buried in the bottom of the pool (1) at a depth of not less than 1 meter.
7. The carbon source slow-release bed for tailwater wetland purification according to claim 1, characterized in that: The total dimensions of the carrier substrate (3) are 2m long and 1.5m wide.