A micro-ecological wetland system and its application

Abstract

This invention provides a micro-ecological wetland system and its application, comprising at least three sequentially connected micro-ecological wetland modules. Each micro-ecological wetland module, arranged according to the water flow direction, includes a wetland unit, a micro-ecological filtration unit, and a collection pond unit. The micro-ecological filtration unit contains filter material, including activated carbon and probiotics compounded on the activated carbon. This invention utilizes a micro-ecological wetland system, increasing biodiversity, improving wetland treatment efficiency, minimizing land modification, avoiding the need for extensive gravel paving, saving investment costs, and allowing for the harvesting of aquatic plants. It also possesses strong resistance to hydraulic shock loads and can be used for the reuse and resource recovery of slightly polluted water.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment, specifically relating to a micro-ecological wetland system and its application. Background Technology

[0002] With rapid socio-economic development, water resources are constantly being damaged. Despite numerous measures being taken, water pollution remains severe.

[0003] Constructed wetlands, as a wastewater ecological treatment technology with low investment, low energy consumption, low treatment costs, and good nitrogen and phosphorus removal capabilities, possess a comprehensive ecosystem and are increasingly being applied in fields such as advanced treatment of wastewater effluent and river and lake ecological restoration. The wetland environment is a rather complex working environment, containing a variety of microorganisms, from surface aerobic bacteria to deep-seated anaerobic bacteria, all of which have a good decomposition effect on biodegradable substances in wastewater.

[0004] Existing constructed wetlands suffer from problems such as monoculture of plants, significant land alteration, high investment costs during application, and low treatment efficiency. As a result, many wetlands fail to achieve satisfactory treatment results, do not meet treatment requirements, and waste a large amount of resources. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a micro-ecological wetland system and its application, which is beneficial to improving the sewage treatment effect and requires less modification to the original land.

[0006] To achieve the above objectives, the technical solution of the present invention is a micro-ecological wetland system, comprising at least three sequentially connected micro-ecological wetland modules. The micro-ecological wetland modules include, in sequence according to the water flow direction, a wetland unit, a micro-ecological filtration unit, and a water collection tank unit. The micro-ecological filtration unit contains filter material, which includes activated carbon and probiotics compounded on the activated carbon.

[0007] In the micro-ecological wetland system of the present invention, micro-ecological wetland modules at all levels are connected in sequence. In one embodiment, a water-proof wall is set between each module. The water-proof wall is made of soil piled up and compacted, and if necessary, it is supplemented with stones.

[0008] In the micro-ecological wetland module of this invention, the water depth of the wetland unit is 0.2–0.6 m, and the bottom of the wetland unit is a natural soil layer. Tall and short aquatic plants are intercropped on the natural soil layer. These tall and short aquatic plants are well-known to those skilled in the art; the tall aquatic plants can be reeds, calamus, or rice, and the short aquatic plants can be bermudagrass, millet grass, or dandelion, without limitation. The wetland unit of this invention can also be planted with purifying aquatic plants. Purifying tall aquatic plants include reeds and calamus, and purifying short aquatic plants include bermudagrass, millet grass, and dandelion. In one embodiment, the area ratio of each wetland unit is 0.5–2. The planting width of the short aquatic plants is 0.5–1.0 m to facilitate personnel access and operation. In the first-level micro-ecological wetland module, the planting width of tall aquatic plants in the wetland unit is 1.0–2.0 m. One or more of the tall and short aquatic plants can be selected according to actual needs. The micro-ecological wetlands of this invention at each level are mixed wetlands of various aquatic plants. Each level of wetland may use different aquatic plants, or different aquatic plants may be included within the same level of wetland. The intercropping of tall and short aquatic plants on the natural soil layer of this invention creates a staggered and orderly vegetation distribution, ensuring good ventilation and light penetration, facilitating shallow water flow, and promoting manual management. This also benefits the photosynthesis of aquatic plants, thereby releasing oxygen and purifying the water. The wetland units in the micro-ecological wetland system described in this invention do not use any external materials, thus possessing the characteristics of natural wetlands. They utilize the in-situ soil and water to cultivate diverse aquatic vegetation. Dissolved oxygen in the water enters through the stomata of plant leaves and reaches the plant roots. Simultaneously, the photosynthesis produced by the vegetation provides oxygen for water purification. Numerous roots and the microorganisms nurtured within them utilize oxygen to carry out biochemical reactions that purify the water, absorbing and decomposing nutrients and promoting the purification process. The micro-ecological wetland modules are interconnected, increasing the biodiversity of the micro-ecological wetland system and significantly improving its wastewater treatment capacity and resilience.

[0009] The microecological filtration unit of this invention comprises a filter material, which includes activated carbon and probiotics compounded on the activated carbon. The probiotics of this invention include two or more of lactic acid bacteria, yeast, Bacillus, and photosynthetic bacteria, wherein the density of the lactic acid bacteria is 10-1. 10 ~10 18 cfu / m 3 The density of the yeast cells is 10. 10 ~10 18 cfu / m 3 The density of the Bacillus is 10. 9 ~10 17 cfu / m 3 The density of the photosynthetic bacteria is 10. 8~10 16 cfu / m 3 The probiotics also include Fe. 2+ The top of the microecological activated carbon filter unit is 10-50 cm higher than the water depth of the wetland unit.

[0010] The filter material of this invention is made by filling activated carbon and probiotics composited on the activated carbon. The preparation method of the filter material includes: fermenting a probiotic raw material liquid, followed by maturation to obtain a fermentation broth; placing activated carbon in the fermentation broth and filling it into a coating material. Specifically, the preparation method involves mixing sucrose, monosodium glutamate, salt, green tea water, wheat bran water, probiotics, nano-iron powder, water, starter, and amino acids in a mass ratio of 30:2:1:100:100:50:5:890:1:1 to obtain a probiotic raw material liquid; fermenting the probiotic raw material liquid at 38°C for 72 hours, followed by maturation to obtain the fermentation broth; during the fermentation process, the nano-iron powder generates Fe under anaerobic conditions. 2+ It can chelate with various organic acids; after mixing activated carbon and the fermentation broth, it is filled into a coating material to obtain a filter material. The coating material can be a filter dam, a chemical fiber mesh bag, or a wire mesh frame, and is not limited thereto. The filling ratio of activated carbon in the filter material is 230-650 kg / m³. 3 The salt used in this invention is preferably crude salt containing inorganic elements; the preparation of the green tea water specifically involves: preferably dry green tea leaves, placed in a hot water constant temperature tank, soaked at 65°C for 8 hours to avoid high temperature damaging tea polyphenols, and then filtering out the tea water; the preparation of the wheat bran water specifically involves: preferably dry wheat bran, placed in a hot water constant temperature tank, soaked at 38°C for 12 hours to avoid high temperature causing starch gelatinization, and then filtering out the juice using a solid-liquid separator; the source of the probiotics is not limited, and any source known to those skilled in the art is acceptable; the particle size of the iron powder is preferably 500nm~10μm; the enzyme can be urea; the amino acids are glutamic acid and tryptophan in a mass ratio of 9:1. Activated carbon and the fermentation liquid are mixed, and the fermentation liquid enters the micropores of the activated carbon material and adheres to the inner surface of the activated carbon. The organic acids and other active substances in the microecological complex bacterial liquid, as well as the chelated ferrous ions, fully enter the micropores of the activated carbon, are slowly released, and exert a continuous effect. Before entering the fermentation tank, the probiotic raw material solution is thoroughly stirred to saturate the dissolved oxygen (approximately 28.3 ml / L), allowing some aerobic and facultative anaerobic microorganisms to multiply in the presence of dissolved oxygen. When the dissolved oxygen in the solution is depleted, the aerobic microorganisms disappear, but their secreted enzymes and active substances remain in the fermentation broth. At the end of fermentation, the surviving probiotics in the fermentation broth include lactic acid bacteria, yeast, Bacillus, and photosynthetic bacteria, with a lactic acid bacteria density of 10-1. 10 ~10 12 The concentration of the yeast was cfu / mL, and the density of the yeast cells was 10.10 ~10 12 cfu / mL, the density of the Bacillus is 10. 9 ~10 11 The cfu / mL concentration of the photosynthetic bacteria was 10⁻⁶. 6 ~10 8 CFU / mL. The probiotics described in this invention can degrade pollutants, synergistically treat wastewater with the microorganisms in the roots of aquatic plants, decompose organic matter in the water, improve soil aggregate structure, and then physically adsorb and retain organic and inorganic matter in the water, improving the plant growth environment, enhancing plant metabolism, and promoting healthy plant growth. The aquatic plants in the wetland unit work synergistically with the probiotics to achieve higher pollutant removal efficiency and stronger resistance to mutation. The microecological filtration unit can purify water while ensuring water passage.

[0011] The water collection tank unit of the present invention includes a hydroponic support frame on which one or more aquatic plants, such as Myriophyllum spicatum, are grown. In one embodiment, the water collection tank unit of the present invention includes a hydroponic support frame on which Myriophyllum spicatum is grown, and the width of the water collection tank unit is 0.5 to 2 m.

[0012] The micro-ecological wetland system of the present invention includes at least three levels of micro-ecological wetland modules connected in sequence. The micro-ecological wetland modules include, in sequence according to the water flow direction, a wetland unit, a micro-ecological filtration unit, and a water collection tank unit. The micro-ecological filtration unit and the water collection tank unit can improve the sewage treatment effect.

[0013] In one embodiment, the micro-ecological wetland system includes five levels of micro-ecological wetland units. The first-level micro-ecological wetland module is planted with one or more of the following purification-type aquatic plants. The second to fifth-level micro-ecological wetland modules are planted with one or more of the following purification-type and economic aquatic plants. The purification-type aquatic plants include reeds, calamus, bermudagrass, millet grass, and bulrush. The economic aquatic plants include rice, aquatic flowers, and aquatic vegetables.

[0014] In one embodiment, the wetland unit of the present invention comprises five sequentially connected micro-ecological wetland modules. The bottom of each wetland unit is a natural soil layer, on which tall and short aquatic plants are intercropped. The first-level micro-ecological wetland module plants one or more of the purifying aquatic plants, while the second to fifth-level micro-ecological wetland modules plant one or more of the purifying and economically valuable aquatic plants. The purifying aquatic plants of the present invention are plants that purify water quality and can effectively absorb elements such as nitrogen and phosphorus in the water, including reeds, calamus, bermudagrass, millet grass, and bulrush. The economically valuable aquatic plants are aquatic plants with economic benefits, including rice, aquatic flowers, and aquatic vegetables. The aquatic flowers include, but are not limited to, Thalia dealbata, and the aquatic vegetables include, but are not limited to, water spinach, water chestnut, and water celery. Reeds are characterized by strong adaptability, large biomass, robust root systems, and hollow stems that facilitate the absorption of large amounts of oxygen. They can absorb and decompose nitrogen, phosphorus, potassium, and other substances in wastewater, thus purifying the water through their own plant structure. Sweet flag, rice, aquatic flowers, and aquatic vegetables all have water purification properties.

[0015] The micro-ecological wetland system of this invention also includes a drainage ditch unit connected to the water collection tank unit. No plants are grown in the drainage ditch unit. A gate is provided at the connection between the water collection tank unit and the drainage ditch unit, and the gate can be opened or closed as needed. The water level in the drainage ditch unit is lower than the water level in the water collection tank unit to ensure smooth drainage.

[0016] The micro-ecological wetland system provided by this invention requires minimal modification to existing land and involves low investment. Furthermore, each level of the micro-ecological wetland module includes a variety of plants, beneficial bacteria, and Fe... 2+ This increases biodiversity, facilitates synergistic treatment, and improves the treatment effect of wetlands. Experimental results show that micro-ecological wetland systems can reduce the nitrogen content in wastewater, promote the cycling of plant nutrients in wastewater, enable the reuse of useful substances in wastewater in the form of crops, green the land, improve the aquatic environment, improve the regional climate, and promote a virtuous cycle of the ecological environment.

[0017] This invention also provides a method for treating wastewater using a micro-ecological wetland system, comprising the following steps:

[0018] Wastewater flows through a micro-ecological wetland system, which includes at least three interconnected micro-ecological wetland modules. Each micro-ecological wetland module includes a wetland unit, a micro-ecological filtration unit, and a collection tank unit in sequence according to the water flow direction. The micro-ecological filtration unit contains filter material, which includes activated carbon and probiotics compounded on the activated carbon.

[0019] Wastewater flows through the micro-ecological wetland system, sequentially passing through various levels of micro-ecological wetland modules. These modules are the same as those described in the aforementioned technical solution and will not be elaborated further. If the water quality meets discharge standards at the third or fourth level of the micro-ecological wetland, the water in the collection tank unit can be released into the drainage ditch and then discharged into the river, simultaneously maintaining water supply for the subsequent wetland vegetation. The plants selected for the wetland units and collection tank units can be chosen according to actual needs. The scale of the micro-ecological wetland system is determined by the volume and degree of wastewater pollution.

[0020] In one embodiment, the micro-ecological filtration unit is a micro-ecological filtration dam structure. Wastewater enters uniformly from the front end of the first-stage micro-ecological wetland module, and after treatment by the wetland unit and the micro-ecological filtration dam unit, it enters the collection tank unit. If the water quality meets the standards, the gate can be opened to allow the qualified water to enter the drainage ditch; otherwise, it enters the second-stage micro-ecological wetland module. Wastewater uniformly entering the second-stage micro-ecological wetland module, after treatment by the wetland unit and the micro-ecological filtration dam unit, enters the collection tank unit. If the water quality meets the standards, the gate can be opened to allow the qualified water to enter the drainage ditch; otherwise, it enters the third-stage micro-ecological wetland module. Wastewater uniformly entering the third-stage micro-ecological wetland module... After being treated by the wetland unit and the micro-ecological filter dam unit, the wastewater enters the collection tank unit. If the water quality meets the standards, the gate can be opened to allow the qualified water to enter the drainage ditch; otherwise, it enters the fourth-level micro-ecological wetland module. Wastewater that enters the fourth-level micro-ecological wetland module is treated by the wetland unit and the micro-ecological filter dam unit and then enters the collection tank unit. If the water quality meets the standards, the gate can be opened to allow the qualified water to enter the drainage ditch; otherwise, it enters the fifth-level micro-ecological wetland module. Wastewater that enters the fifth-level micro-ecological wetland module is treated by the wetland unit and the micro-ecological filter dam unit and then enters the collection tank unit, allowing the qualified water to enter the drainage ditch. The effluent from the drainage ditch is then discharged in compliance with standards.

[0021] In one embodiment, the micro-ecological filtration unit is a unit with a micro-ecological filtration dam structure. Wastewater flows sequentially through a five-stage micro-ecological wetland system. The first-stage micro-ecological wetland module, according to the water flow direction, includes a wetland unit intercropped with reeds and bermudagrass, a micro-ecological filtration dam unit, and a collection pond unit planted with foxtail grass. The second-stage micro-ecological wetland module, according to the water flow direction, includes a wetland unit intercropped with thaliana and bermudagrass, a micro-ecological filtration dam unit, and a collection pond unit planted with foxtail grass. The third-stage micro-ecological wetland module, according to the water flow direction, includes... The first level of the micro-ecological wetland module consists of three sections: a wetland unit for planting rice and bermudagrass, a micro-ecological filtration dam unit, and a water collection pond unit for planting foxtail grass; the second level of the micro-ecological wetland module consists of three sections: a wetland unit for intercropping water chestnuts and bermudagrass, a micro-ecological filtration dam unit, and a water collection pond unit for planting foxtail grass; the third level of the micro-ecological wetland module consists of three sections for intercropping water chestnuts and bermudagrass, a micro-ecological filtration dam unit, and a water collection pond unit for planting foxtail grass. The water in the water collection pond unit meets the discharge standards and can be placed into the drainage ditch and then discharged into the river.

[0022] This invention provides a micro-ecological wetland system, comprising at least three sequentially connected micro-ecological wetland modules. Each micro-ecological wetland module, arranged according to the water flow direction, includes a wetland unit, a micro-ecological filtration unit, and a collection pond unit. The micro-ecological filtration unit contains filter material, including activated carbon and probiotics compounded on the activated carbon. This invention utilizes a micro-ecological wetland system, which on the one hand increases biodiversity and improves wetland treatment efficiency; on the other hand, it requires minimal modification to existing land, avoids laying large amounts of gravel in the wetland, saving investment costs, and simultaneously allows for the harvesting of aquatic plants. The micro-ecological wetland system includes various plants, various probiotics, and Fe... 2+ This invention promotes the cycling of plant nutrients in wastewater, allowing crops to reuse these nutrients, thus greening the land, improving the regional climate, and fostering a healthy ecological cycle. It boasts advantages such as high efficiency, low investment, low operating costs, low maintenance requirements, and low power consumption. The micro-ecological wetland system used for wastewater treatment is relatively inexpensive to construct, has low operating and maintenance costs, is simple to implement, generally requires only periodic maintenance, has strong resistance to hydraulic shock loads, can be used for the reuse and resource recovery of slightly polluted water, possesses inherent landscape benefits, can be effectively integrated with natural landscapes, and is easily accepted by the public. Attached Figure Description

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] Figure 1 A schematic diagram of a five-level micro-ecological wetland system;

[0025] Figure 2 A schematic diagram of a five-level micro-ecological wetland system for wastewater treatment;

[0026] Figure 3 This is a schematic diagram of a fifth-level micro-ecological wetland module with mixed vegetation.

[0027] Figure 4 The effect of microecological chelated iron activated carbon sheets on the removal of nitrate ions in the effluent of sewage treatment plants;

[0028] Figure 5 The effect of microecological chelated iron activated carbon sheets on the removal of nitrate ions in polluted water;

[0029] Figure 6 The effect of gauze bags containing microecological chelated iron activated carbon on the treatment of polluted water. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] First, a micro-ecological filtration dam is prepared.

[0033] Dried green tea leaves were placed in a hot water constant temperature tank and steeped at 65℃ for 8 hours, then filtered to obtain green tea water. Dried wheat bran was placed in a hot water constant temperature tank and steeped at 38℃ for 12 hours, then filtered using a solid-liquid separator to obtain wheat bran water. Sucrose, monosodium glutamate, salt, green tea water, wheat bran water, probiotics, nano-iron powder, water, starter, and amino acids were mixed in a mass ratio of 30:2:1:100:100:50:5:890:1:1 to obtain a probiotic raw material liquid. This probiotic raw material liquid was placed in a stirred tank and sealed, then fermented at 38℃ for 72 hours. The first half of the fermentation was facultative anaerobic fermentation, consuming dissolved oxygen, followed by an automatic transition to anaerobic fermentation in the second half. Under anaerobic conditions, the nano-iron powder generated Fe... 2+ After fermentation is complete, the fermentation liquid is transferred to a post-fermentation tank, sealed, and left for two weeks to allow any remaining sugars to ferment completely and to eliminate any potential gas releases, yielding the fermentation liquid. Activated carbon is then mixed with the fermentation liquid and filled into a filter dam at a ratio of 600 kg / m³. 3 The density of lactic acid bacteria was 1.2 × 10⁻⁶. 14 cfu / m3 The yeast density is 0.8 × 10⁻⁶. 14 cfu / m 3 The density of Bacillus was 1.1 × 10⁻⁶. 13 cfu / m 3 The density of photosynthetic bacteria is 1.8 × 10⁻⁶. 12 cfu / m 3 This results in a micro-ecological filtration dam. (See also...) Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of a five-level micro-ecological wetland system. Figure 2 This diagram illustrates a five-level micro-ecological wetland system for wastewater treatment. The specific steps involved in wastewater treatment using this system are as follows:

[0034] Near Jianghou Village in the Wenchang River basin of Wenchang City, Hainan Province, a five-stage micro-ecological wetland dialysis system was constructed, diverting a portion of the Wenchang River water into the five-stage wetland system. The river water flows sequentially through the five-stage micro-ecological wetland system. The first-stage micro-ecological wetland module, according to the water flow direction, includes a wetland unit intercropped with reeds and bermudagrass, a micro-ecological filtration dam unit, and a collection pond unit with foxtail algae planted on bamboo rafts. The water is treated in the first-stage wetland module for 24 hours, with the average flow velocity of wastewater through the micro-ecological filtration dam being 1260 kg / m³. -2 h -1 Then it is discharged into the second-level micro-ecological wetland module.

[0035] Wastewater enters the second-stage micro-ecological wetland module. This module, arranged sequentially according to water flow direction, includes a wetland unit intercropped with Thalia dealbata and Bermuda grass, a micro-ecological filter dam unit, and a collection pond unit with Myriophyllum spica planted on a bamboo raft. The water is treated in the second-stage wetland module for 24 hours, with an average flow velocity of 1140 kg / m³ through the micro-ecological filter dam. - 2 h -1 Then it is discharged into the third-level micro-ecological wetland module.

[0036] Wastewater enters the third-level micro-ecological wetland module, which, according to the water flow direction, includes a wetland unit intercropped with rice and bermudagrass, a micro-ecological filter dam unit, and a collection pond unit with myriophyllum spica planted on a bamboo raft. After 24 hours of treatment in the third-level wetland module, the average flow velocity of wastewater through the micro-ecological filter dam is 1070 kg / m³. - 2 h -1 Then it is discharged into the fourth-level micro-ecological wetland module.

[0037] Wastewater enters the fourth-level micro-ecological wetland module. This module, arranged sequentially according to water flow direction, includes a wetland unit intercropped with water chestnuts and bermudagrass, a micro-ecological filter dam unit, and a collection pond unit with *Myriophyllum spicatum* planted on a bamboo raft. After 24 hours of treatment in the fourth-level wetland module, the average flow velocity of wastewater through the micro-ecological filter dam is 980 kg / m³. - 2 h -1 Then it is discharged into the fifth-level micro-ecological wetland module.

[0038] Wastewater enters the fifth-level micro-ecological wetland module. This module, arranged sequentially according to water flow direction, includes a wetland unit intercropped with water chestnuts and bermudagrass, a micro-ecological filter dam unit, and a collection pond unit on a bamboo raft planted with foxtail grass and aquatic plants. After 24 hours of treatment in the fifth-level wetland module, the average flow velocity of wastewater through the micro-ecological filter dam is 910 kg / m³. -2 h -1 The water in the collection tank unit meets the discharge standards and can be discharged into the drainage ditch, and then into the river.

[0039] Nitrate content detection: Place the test tube containing the water sample in a 105℃ incubator for 5 minutes to inactivate the cells. Then, at room temperature, use an RQFlex spectrophotometer to detect the nitrate ion content.

[0040] The test results showed that before the treatment, the water quality of the Wenchang River was Class V (COD 65mg / L, nitrate 50ppm). After the treatment, the pollution source was eliminated, the water quality became clear and transparent, and it reached Class III surface water (COD 18mg / L, nitrate 9.8ppm). The micro-ecological level 5 wetland effectively reduced the concentration of nitrate ions in the water.

[0041] Example 2:

[0042] A microecological filter dam was prepared according to the method in Implementation 1, wherein the activated carbon was coconut shell activated carbon, and the filling ratio of activated carbon was 500 kg / m³. 3 In the first-stage microecological filtration dam unit, the density of lactic acid bacteria is 1.2 × 10⁻⁶. 14 cfu / m 3 The yeast density is 0.8 × 10⁻⁶. 14 cfu / m 3 The density of Bacillus was 1.1 × 10⁻⁶. 13 cfu / m 3 The density of photosynthetic bacteria is 1.8 × 10⁻⁶. 12 cfu / m 3 In the second-stage microecological filtration dam unit, the density of lactic acid bacteria is 0.6 × 10⁶. 14 cfu / m 3 The yeast density is 0.4 × 10⁻⁶.14 cfu / m 3 The density of Bacillus was 0.55 × 10⁻⁶. 13 cfu / m 3 The density of photosynthetic bacteria is 0.9 × 10⁻⁶. 12 cfu / m 3 In the third-level microecological filtration dam unit, the density of lactic acid bacteria was 0.4 × 10⁻⁶. 14 cfu / m 3 The yeast density is 0.27 × 10⁻⁶. 14 cfu / m 3 The density of Bacillus was 0.37 × 10⁻⁶. 13 cfu / m 3 The density of photosynthetic bacteria is 0.6 × 10⁶. 12 cfu / m 3 In the fourth-level microecological filtration dam unit, the density of lactic acid bacteria is 0.3 × 10⁻⁶. 14 cfu / m 3 The yeast density is 0.2 × 10⁻⁶. 14 cfu / m 3 The density of Bacillus was 0.28 × 10⁻⁶. 13 cfu / m 3 The density of photosynthetic bacteria is 0.45 × 10⁻⁶. 12 cfu / m 3 In the fifth-level microecological filtration dam unit, the density of lactic acid bacteria was 0.24 × 10⁻⁶. 14 cfu / m 3 The yeast density is 0.16 × 10⁻⁶. 14 cfu / m 3 The density of Bacillus was 0.22 × 10⁻⁶. 13 cfu / m 3 The density of photosynthetic bacteria was 0.36 × 10⁻⁶. 12 cfu / m 3 .

[0043] The project was implemented on a farm in a Southeast Asian country with a climate similar to Hainan Province. The wastewater source was the farm's staff residential area. The wetland system was a five-level micro-ecological small wetland system with a total area of ​​5,000 square meters, with each level of wetland covering an area of ​​1,000 square meters.

[0044] The first-level micro-ecological wetland module, arranged sequentially according to water flow direction, includes wetland units, micro-ecological filter dam units, and a collection pond unit planted with foxtail grass on a bamboo raft. The wetland units are intercropped with tall aquatic plants such as reeds (planting band 2 meters wide) and short aquatic plants such as bermudagrass and millet grass (planting band 1 meter wide). After 24 hours of treatment in the first-level micro-ecological wetland module, the average flow velocity of wastewater through the micro-ecological filter dam is 680 kg / m³.-2 h -1 Then it is discharged into the second-level micro-ecological wetland module.

[0045] Wastewater enters the second-stage micro-ecological wetland module. This module, arranged sequentially according to water flow direction, includes a wetland unit intercropped with reeds and bermudagrass, a micro-ecological filtration dam unit, and a collection pond unit with *Myriophyllum spicatum* planted on a bamboo raft. The water is treated in the second-stage micro-ecological wetland module for 24 hours. The average flow velocity of wastewater through the micro-ecological filtration dam is 560 kg / m³. -2 h -1 Then it is discharged into the third-level micro-ecological wetland module.

[0046] Wastewater enters the third-level micro-ecological wetland module. This module, arranged sequentially according to water flow direction, includes a wetland unit intercropped with Thalia dealbata and Bermuda grass, a micro-ecological filtration dam unit, and a collection pond unit planted with Myriophyllum spicatum on a bamboo raft. The water is treated in the third-level micro-ecological wetland module for 24 hours. The average flow velocity of wastewater through the micro-ecological filtration dam is 540 kg / m³. -2 h -1 Then it is discharged into the fourth-level micro-ecological wetland module.

[0047] Wastewater enters the fourth-level micro-ecological wetland module. This module, arranged sequentially according to water flow direction, includes a wetland unit intercropped with water chestnuts and bermudagrass, a micro-ecological filtration dam unit, and a collection pond unit with *Myriophyllum spicatum* planted on a bamboo raft. The water is treated in the fourth-level micro-ecological wetland module for 24 hours. The average flow velocity of wastewater through the micro-ecological filtration dam is 490 kg / m³. -2 h -1 Then it is discharged into the fifth-level micro-ecological wetland module.

[0048] Wastewater enters the fifth-level micro-ecological wetland module. Figure 3 This is a schematic diagram of a mixed-vegetation fifth-level micro-ecological wetland module. The fifth-level micro-ecological wetland module, arranged sequentially according to water flow direction, includes wetland units, micro-ecological filter dam units, and a collection pond unit. The wetland units are intercropped with water celery, bermudagrass, water spinach, bermudagrass, and water chestnuts. The collection pond unit is planted with foxtail grass and aquatic plants on bamboo rafts. The water is treated in the fifth-level micro-ecological wetland module for 24 hours, and the average flow velocity of wastewater through the micro-ecological filter dam is 450 kg / m³. -2 h -1 And then it is discharged into the river.

[0049] The nitrate content in the water was tested according to the method in Example 1, and the results are shown in Table 1. Table 1 shows the purification effect of the five-level wetland system.

[0050] Table 1. Purification effect of the five-level wetland system

[0051]

[0052] The test results showed that before treatment, the wastewater was classified as Class V (COD 473.5 mg / L, nitrate 50 ppm). After treatment, the odor from the pollution source was eliminated, the water was crystal clear, and the COD and nitrate content reached Class III surface water (COD 9 mg / L, nitrate 9.8 ppm). The micro-ecological level 5 wetland effectively reduced the concentration of nitrate ions in the water.

[0053] Example 3:

[0054] First, a microecological chelated iron activated carbon sheet is prepared.

[0055] Dry green tea leaves are placed in a constant-temperature hot water tank at a constant temperature of 65℃ and steeped for 8 hours. The steeped water is then filtered to obtain green tea water. Dry wheat bran is placed in a constant-temperature hot water tank at a constant temperature of 38℃ and steeped for 12 hours. The liquid is then filtered out using a solid-liquid separator to obtain wheat bran water. Sucrose, monosodium glutamate, salt, green tea water, wheat bran water, probiotics, nano-iron powder, water, starter, and amino acids are mixed in a mass ratio of 30:2:1:100:100:50:5:890:1:1 to obtain a probiotic raw material liquid. This probiotic raw material liquid is then placed in a sealed mixing tank and fermented at 38℃ for 72 hours. The first half of the fermentation is facultative anaerobic fermentation, which consumes dissolved oxygen. The second half of the fermentation automatically transitions to anaerobic fermentation, where nano-iron powder generates Fe. 2+ After fermentation is complete, the fermentation liquid is transferred to a post-fermentation tank, sealed, and left for two weeks to allow any remaining sugars to ferment completely and to eliminate any potential gas releases, yielding the fermentation liquid. Activated carbon is then added to the fermentation liquid and mixed, and the mixture is filled into two layers of synthetic fiber gauze at a ratio of 230 kg / m². 3 A rectangular sheet of microecological chelated iron activated carbon was obtained by embedding a net-shaped lead weight along one long side and several floating balls along the other long side. The density of lactic acid bacteria in the sheet was 1.5 × 10⁻⁶. 14 cfu / m 3 The density of yeast cells is 1×10⁻⁶. 14 cfu / m 3 The density of Bacillus was 1.5 × 10⁻⁶. 13 cfu / m 3 The density of photosynthetic bacteria is 1.5 × 10⁻⁶. 12 cfu / m 3 .

[0056] Wastewater effluent from a wastewater treatment plant containing 200 ppm nitrate ions was subjected to further treatment. A wire mesh basket (4 meters long, 2 meters wide, and 1 meter high) was lined with mats containing micro-ecological chelated iron activated carbon at its bottom and four walls. A longitudinal activated carbon mat was placed every 0.5 meters along the long side. The wire mesh basket was placed at a 15° angle along its long side. The effluent was poured into the first square and then flowed down the slope, passing through seven activated carbon mats. Water samples were taken after each mat to determine the nitrate ion concentration.

[0057] The results are as follows Figure 4 As shown, Figure 4 The effect of microecological chelated iron activated carbon sheets on the removal of nitrate ions in wastewater treatment plant effluent was investigated. The results showed that after passing through 7 activated carbon sheets, the nitrate ion concentration decreased from 200 ppm to 38 ppm, meeting the discharge standards.

[0058] Example 4:

[0059] Six sheets of microecological chelated iron activated carbon obtained in Example 3 were placed on a shelf. Polluted river water was sprayed on top, allowing the water to continuously pass through the six layers of microecological activated carbon gauze sheets. Water samples were taken from the bottom of each layer to determine the concentration of nitrate ions. The water temperature and room temperature were both 22±2℃.

[0060] The results are as follows Figure 5 As shown, Figure 5 The effect of microecological chelated iron activated carbon sheets on the removal of nitrate ions in polluted water was investigated. The results showed that after the water passed through 6 layers of sheets, the concentration of nitrate ions in the water decreased to 40 ppm.

[0061] Example 5:

[0062] Polluted water containing 500 ppm nitrate ions was placed in a 1000 mL beaker. A gauze bag containing 100 mL of microecological chelated iron activated carbon was suspended in the water. The gauze bag containing microecological chelated iron activated carbon was obtained according to Example 3. The beaker was placed on a magnetic stirrer, and the rotor inside the beaker was continuously rotated to agitate the water. The water temperature was controlled at 22°C. Water samples were taken every 10 minutes to determine the nitrate ion content.

[0063] Over time, the concentration of nitrate ions in the water gradually decreases, resulting in the following... Figure 6 As shown, Figure 6 The effect of gauze bags containing microecological chelated iron activated carbon on the treatment of polluted water was investigated. The results showed that the concentration of nitrate ions in the gauze bags significantly decreased with prolonged treatment time.

[0064] Example 6:

[0065] No iron powder was added during the probiotic fermentation process, and the final fermentation broth contained no nano-chelated iron ions, significantly reducing the rate of nitrate reduction (4.1 mg / kg). -1 day -1 It contains nano-chelated iron (17.5 mg / kg). -1 day -1 23% of Fe. Therefore, Fe 2+ When used in combination with probiotics, it can effectively improve the treatment of nitrate ions.

[0066] Comparative Example 1:

[0067] Without using the probiotic strains of this invention, but instead using a single yeast strain, even with iron powder and activated carbon, the nitrate reduction rate is 7.2 mg / kg. -1 day -1 It uses compound bacteria (17.5 mg / kg) -1 day -1 41% of the total. Therefore, the use of probiotics can effectively improve the treatment effect of nitrate ions.

[0068] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A micro-ecological wetland system, characterized in that, The micro-ecological wetland system comprises at least three micro-ecological wetland modules connected in sequence, and the micro-ecological wetland modules comprise a wetland unit, a micro-ecological filter unit and a water collecting pool unit in sequence according to the water flow direction. The micro-ecological filter unit comprises filter material, and the filter material comprises activated carbon and probiotics compounded on the activated carbon. The probiotics are composed of lactic acid bacteria, yeast, bacillus and photosynthetic bacteria. The preparation method of the filter material is as follows: sucrose, sodium glutamate, salt, green tea water, wheat bran water, probiotics, nano iron powder, water, leavening agent and amino acid are mixed to obtain a probiotic raw material solution, the probiotic raw material solution is fermented to obtain a fermentation liquor, the nano iron powder generates Fe 2+ under anaerobic conditions, the fermentation liquor is mixed with the activated carbon to obtain the filter material.

2. The micro-ecological wetland system according to claim 1, wherein, The density of the lactic acid bacteria is 10 10 ~10 18 cfu / m 3 The density of the yeast bacteria is 10 10 ~10 18 cfu / m 3 The density of the bacillus bacteria is 10 9 ~10 17 cfu / m 3 The density of the photosynthetic bacteria is 10 8 ~10 16 cfu / m 3 .

3. The micro-ecological wetland system according to claim 1, wherein, The micro-ecological wetland system comprises five micro-ecological wetland modules connected in sequence.

4. The micro-ecological wetland system according to claim 3, wherein, The bottom of the wetland unit is a natural soil layer, and tall and short aquatic plants are interplanted on the natural soil layer; the water collecting pool unit comprises a water culture support, and one or more aquatic plants are planted on the water culture support.

5. The micro-ecological wetland system according to claim 3, wherein, The first micro-ecological wetland module plants one or more of purifying aquatic plants, and the second to fifth micro-ecological wetland modules plant one or more of purifying aquatic plants and economic aquatic plants.

6. The micro-ecological wetland system according to claim 5, wherein, The purifying aquatic plants comprise reed, alocasia, dog tooth grass, small rice grass and cow hair felt grass, and the economic aquatic plants comprise rice, aquatic flowers and aquatic vegetables.

7. The micro-ecological wetland system according to claim 1, wherein, The water depth of the wetland unit is 0.2-0.6 m, and the top of the micro-ecological filter unit is 10-50 cm higher than the water depth of the wetland unit.

8. A method for treating sewage water in a micro-ecological wetland system, characterized by, The micro-ecological wetland system comprises the following steps: Sewage flows through the micro-ecological wetland system according to any one of claims 1-7, and the micro-ecological wetland system comprises at least three micro-ecological wetland modules connected in sequence, and the micro-ecological wetland modules comprise a wetland unit, a micro-ecological filter unit and a water collecting pool unit in sequence according to the water flow direction. The micro-ecological filter unit comprises filter material, and the filter material comprises activated carbon and probiotics compounded on the activated carbon.

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