A method for constructing ecological slope protection based on bacteria-algae symbiotic system

Abstract

The present invention provides an ecological slope protection construction method based on a bacteria-algae symbiotic system, which relates to the technical field of runoff sewage treatment, and includes the following steps: mixing biochar with ceramsite, then reacting for 8 to 20 hours under the conditions of 120 to 160°C and 4 to 6MPa, adding a water retaining agent after cooling, obtaining a microbial carrier material, and then applying it to the surface layer of the river slope protection soil; dividing the river slope protection into tree areas, shrub areas, herbaceous plant areas and emergent plant areas, and planting trees, shrubs, herbaceous plants and emergent plants respectively; spraying the bacteria-algae mixed liquid on the surface of the river slope protection soil to form a biological soil crust. The present invention utilizes the porous structure of biochar to improve soil bulk density and pore structure, and is matched with ceramsite and a water retaining agent to improve soil permeability, moisture content and water holding capacity, promote the growth of bacteria and algae, thereby improving the purification effect, and using vegetation to alleviate the erosion of the river bank by water flow, solving the problem that the flood control measures on the river bank destroy the integrity of the river.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to an ecological slope protection construction method based on a bacteria-algae symbiotic system. Background Art

[0002] Non-point source pollution is one of the main sources of river pollution, including agricultural runoff, street runoff, atmospheric pollutant deposition, mining sites, roads, railways, etc. Basin non-point source pollution can affect the entire river ecosystem through the water cycle. Due to its randomness, widespread nature and difficulty in governance, it has become the main factor in polluting surface water.

[0003] The riparian zone is considered to be an effective means of protecting aquatic ecosystems from non-point source pollutants. The degree of attenuation of non-point source pollutants is closely related to the riparian zone plant configuration, substrate configuration, and bank protection structure type. Previous riparian zone configurations overemphasized the reinforcement and flood control capabilities of the riverbank (such as pile-board slope protection and mortar masonry), which will lead to a disconnect between aquatic and terrestrial ecosystems, thereby destroying the integrity of the river and losing the ecological function of the riparian zone. Therefore, it is urgent to develop a new type of slope ecological management technology that can not only avoid riverbank erosion caused by accelerated river flow, but also intercept and purify non-point source pollution and purify water quality.

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide an ecological slope protection construction method based on a bacteria-algae symbiotic system, which can effectively control the impact of non-point source pollution on river water quality, reduce riverbank runoff and slope erosion, and promote the growth of vegetation on the slope, so as to solve the problem that flood control measures on the river bank damage the integrity of the river.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for constructing an ecological slope protection system based on a bacterial-algal symbiotic system comprises the following steps:

[0008] S1, 5 to 8 parts by weight of biochar and 2 to 3 parts by weight of ceramsite are mixed, and then reacted at 120 to 160° C. and 4 to 6 MPa for 8 to 20 hours, cooled to room temperature, 0.1 to 2 parts by weight of a water retaining agent are added and mixed to obtain a microbial carrier material, and then the microbial carrier material is applied to the surface layer of the river slope protection soil;

[0009] S2. Divide the river bank protection into tree area, shrub area, herbaceous plant area and emergent plant area in the order from far to near the center line of the river channel, and plant trees, shrubs, herbaceous plants and emergent plants in the tree area, shrub area, herbaceous plant area and emergent plant area respectively;

[0010] S3, spraying the bacteria-algae mixed solution on the surface of the river slope protection soil to form a biological soil crust; the bacteria-algae mixed solution is obtained by mixing a fungus culture solution with an algae culture solution, the fungus culture solution is inoculated with nitrogen-fixing bacteria and phosphate-dissolving bacteria, and the algae culture solution is inoculated with sheath algae.

[0011] Preferably, in step S1, the water-retaining agent is sodium oxalate.

[0012] Preferably, in step S2, the tree includes at least one of Ailanthus toon, Cinnamomum camphora and Metasequoia glyptostroboides, the shrub is Hibiscus, the herbaceous plant includes Vetiver and / or Phragmites australis, and the emergent plant includes Phragmites australis and / or Calamus calamus.

[0013] Preferably, the raw materials of the algae culture solution include, by weight, 1500 parts of sodium nitrate, 75 parts of magnesium sulfate heptahydrate, 40 parts of dipotassium hydrogen phosphate, 36 parts of calcium chloride, 20 parts of sodium carbonate, 20 parts of citric acid, 15 parts of ammonium ferric citrate, 10 parts of EDTA sodium salt, and 10 parts of boric acid, and the algae culture solution is sterilized.

[0014] Preferably, the preparation method of the fungus culture solution is as follows: taking the filtrate of the activated sludge, diluting it with distilled water, putting it into a high-pressure sterilizer for sterilization, and cooling it to room temperature to obtain the fungus culture solution.

[0015] Preferably, the preparation method of the bacteria-algae mixed solution is as follows:

[0016] Step 1, inoculating nitrogen-fixing bacteria and phosphate-dissolving bacteria into the fungus culture solution respectively, and culturing at 25° C. for 72 hours to obtain nitrogen-fixing bacteria culture solution and phosphate-dissolving bacteria culture solution respectively;

[0017] Step 2, inoculating the sheathed filamentous algae into the algae culture solution, and culturing at 25° C. for 168 hours to obtain the sheathed filamentous algae culture solution;

[0018] Step 3, centrifuging the culture solution of step 1 and step 2 at high speed to remove the supernatant;

[0019] Step 4: Take the nitrogen-fixing bacteria culture solution and the phosphate-dissolving bacteria culture solution obtained after centrifugation in step 3, and mix them with the sheath algae culture solution obtained in step 2 in proportion to obtain the bacteria-algae mixed solution.

[0020] Preferably, the filtrate of the activated sludge is diluted with distilled water to a total nitrogen concentration of less than 15 mg / L and a total phosphorus concentration of less than 1 mg / L.

[0021] Preferably, in step 4, the culture solution of nitrogen-fixing bacteria and the culture solution of phosphate-dissolving bacteria are mixed in a volume ratio of 1:(1-3) to obtain a fungus mixed solution, and then the fungus mixed solution is mixed with the culture solution of the sheath algae obtained in step 2 in a volume ratio of (3-5):(1-3) to obtain the bacteria-algae mixed solution.

[0022] Beneficial effects:

[0023] (1) The present invention applies a microbial carrier material on the soil surface. On the one hand, the porous structure of biochar can improve the bulk density and pore structure of the soil. When combined with expanded clay and a water-retaining agent (sodium oxalate), the permeability, moisture content and water holding capacity of the soil can be improved, providing a suitable living environment for bacteria and algae in the soil. On the other hand, it can also serve as a carrier for the growth of bacteria and algae, promoting the growth of bacteria and algae and forming a biological soil crust in the river slope protection soil layer, thereby solving the problem that conventional microorganisms with water purification functions are difficult to survive outside the water body, and greatly improving the purification effect.

[0024] (2) The present invention combines herbs (vetiver, reed) and emergent plants (reed, calamus) to form a strong root network to stabilize the slope soil, thereby curbing soil erosion and preventing slope erosion.

[0025] (3) The present invention sets up a combination of trees (Ailanthus toon, Cinnamomum camphora, Metasequoia), shrubs (Hibiscus), herbs (Vetiver, Reed) and emergent plants (Phragmites australis, Acorus calamus). The diversified plant configuration is conducive to increasing the interception and purification capacity of non-point source pollutants. In addition, plants can act as a medium for purifying land-based pollution by enhancing the absorption and degradation process and directly utilizing nitrogen, phosphorus and other nutrients. They can also accumulate toxic elements such as heavy metals and antibiotics in rainwater runoff, thereby improving river water quality.

[0026] (4) The bacteria-algae mixed solution of the present invention is a mixture of nitrogen-fixing bacteria Azospirillum brasilense, phosphate-dissolving bacteria Pantoeaagglomerans IALR1325 and scaly algae in proportion. When the bacteria-algae mixed solution is applied to the riparian soil, the algae can not only fix nitrogen, but also provide oxygen for the bacteria through photosynthesis; while the bacteria convert nitrogen and phosphorus into nutrients that can be used by plants, their secretions can also promote the growth of algae, and the two form a mutually beneficial symbiotic effect. The bacteria-algae mixed solution can convert nitrogen and phosphorus in runoff into nutrients that can be used by plants, thereby promoting the growth of riparian plants and improving the water quality of the river. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0028] Figure 1 This is a schematic structural diagram of an ecological slope protection provided as an application example of the present invention.

[0029] In the picture: 1. Tree area; 2. Shrub area; 3. Herbaceous plant area; 4. Emergent plant area. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0031] The present invention will be described in detail below in conjunction with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0032] In view of the problem that current riverbank reinforcement measures cannot take into account both slope protection and non-point source pollution control, the present invention provides an ecological slope protection construction method based on a bacteria-algae symbiotic system, comprising the following steps:

[0033] S1, 5-8 parts by weight of biochar and 2-3 (e.g., 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9) parts by weight of ceramsite are mixed, and then heated at 120-160°C (e.g., 121°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 159°C), 4-6MPa (e.g., 4.1MPa, 4.3MPa, 4.5MPa, 4.7MPa, 4.9MPa, 5.0MPa, 5.1MPa, 5.2MPa, 5.3MPa, 5.4MPa, 5.6MPa, 5.7MPa, 5.8MPa, 5.9MPa, 5.9MPa, 5.1MPa, 5.2MPa, 5.8 ... .1MPa, 5.3MPa, 5.5MPa, 5.7MPa, 5.9MPa) for 8-20h (e.g., 9h, 10h, 11h, 13h, 15h, 17h, 19h), cooled to room temperature, adding 0.1-2 (e.g., 0.2, 0.3, 0.5, 0.7, 0.9, 1.0, 1.1, 1.3, 1.5, 1.7, 1.9) parts by weight of a water retaining agent and mixing to obtain a microbial carrier material, and then applying the microbial carrier material to the surface layer of the river slope protection soil;

[0034] S2. In the order from far to near the center line of the river, divide the river bank into tree area 1, shrub area 2, herbaceous plant area 3 and emergent plant area 4, such as Figure 1As shown, trees, shrubs, herbaceous plants and emergent plants are planted in tree area 1, shrub area 2, herbaceous plant area 3 and emergent plant area 4 respectively;

[0035] S3, spraying the bacteria-algae mixed solution on the surface of the river slope protection soil to form a biological soil crust; the bacteria-algae mixed solution is obtained by mixing a fungus culture solution with an algae culture solution, the fungus culture solution is inoculated with nitrogen-fixing bacteria and phosphate-dissolving bacteria, and the algae culture solution is inoculated with sheathed filamentous algae.

[0036] The present invention applies microbial carrier materials on the soil surface. On the one hand, the porous structure of biochar can improve the bulk density and pore structure of the soil. When combined with expanded clay and water-retaining agents, the permeability, moisture content and water-holding capacity of the soil can be improved, providing a suitable living environment for bacteria and algae in the soil. On the other hand, it can also serve as a carrier for the growth of bacteria and algae, promoting their growth, solving the problem that conventional microorganisms with water purification functions are difficult to survive outside the water body, thereby greatly improving the purification effect.

[0037] In a preferred embodiment of the present invention, in step S1, the water retaining agent is sodium oxalate, and other water retaining agents with similar functions such as polyacrylamide and sodium polyacrylate may also be used to replace sodium oxalate.

[0038] In a preferred embodiment of the present invention, in step S2, the trees include at least one of Ailanthus toon, Cinnamomum camphora and Metasequoia glyptostroboides, the shrubs are hibiscus, the herbs include vetiver and / or reed, and the emergent plants include reed and / or calamus. Through the combination of trees, shrubs, herbs and emergent plants, the diversified plant configuration is conducive to increasing the interception and purification capacity of non-point source pollutants. In addition, plants can act as a medium for purifying land-based pollution by enhancing absorption and degradation processes and directly utilizing nitrogen, phosphorus and other nutrients. They can also accumulate toxic elements, such as heavy metals and antibiotics in rainwater runoff, thereby improving river water quality.

[0039] In a preferred embodiment of the present invention, the raw materials of the algae culture solution include, by weight, 1500 parts of sodium nitrate, 75 parts of magnesium sulfate heptahydrate, 40 parts of dipotassium hydrogen phosphate, 36 parts of calcium chloride, 20 parts of sodium carbonate, 20 parts of citric acid, 15 parts of ammonium ferric citrate, 10 parts of EDTA sodium salt, and 10 parts of boric acid, and the algae culture solution is sterilized.

[0040] In a preferred embodiment of the present invention, the method for preparing the fungus culture solution is as follows: taking the filtrate of the activated sludge, diluting it with distilled water, putting it into a high pressure sterilizer for sterilization, and cooling it to room temperature to obtain the fungus culture solution.

[0041] In a preferred embodiment of the present invention, the preparation method of the bacteria-algae mixed solution is as follows:

[0042] Step 1, inoculating nitrogen-fixing bacteria and phosphate-dissolving bacteria into fungal culture solution respectively, and culturing at 25° C. for 72 hours to obtain nitrogen-fixing bacteria culture solution and phosphate-dissolving bacteria culture solution respectively;

[0043] Step 2, inoculating the sheathed filamentous algae into an algae culture solution, and culturing at 25° C. for 168 hours to obtain a sheathed filamentous algae culture solution;

[0044] Step 3, centrifuging the culture solution of step 1 and step 2 at high speed to remove the supernatant;

[0045] Step 4: Take the nitrogen-fixing bacteria culture solution and the phosphate-dissolving bacteria culture solution obtained after centrifugation in step 3, and mix them with the sheath algae culture solution obtained in step 2 according to a certain proportion to obtain a bacteria-algae mixed solution.

[0046] In a preferred embodiment of the present invention, the filtrate of the activated sludge is diluted with distilled water to a total nitrogen concentration of less than 15 mg / L and a total phosphorus concentration of less than 1 mg / L.

[0047] In a preferred embodiment of the present invention, in step four, the nitrogen-fixing bacteria culture solution and the phosphate-solubilizing bacteria culture solution are mixed in a volume ratio of 1: (1-3), for example, 1:1.1, 1:1.3, 1:1.5, 1:1.7, 1:1.9, 1:2, 1:2.1, 1:2.3, 1:2.5, 1:2.7, 1:2.9, to obtain a fungus mixture, and then the fungus mixture is mixed with the sheath algae culture solution obtained in step two in a volume ratio of (3-5): (1-3), for example, 3:3, 3.3:2.7, 3.5:2.5, 3.7:2.3, 4:2, 4.3:1.7, 4.5:1.5, 4.7:1.3, 5:1, to obtain a bacteria-algae mixture.

[0048] The following is a detailed description of a method for constructing an ecological slope protection system based on a bacteria-algae symbiotic system according to the present invention through specific embodiments.

[0049] In the following embodiments:

[0050] The activated sludge filtrate was from Hefei Wangxiaoying Wastewater Treatment Plant;

[0051] The nitrogen-fixing bacteria Azospirillum brasilense was purchased from Shanghai Yubo Biotechnology Co., Ltd., and the phosphate-solubilizing bacteria Pantoea agglomerans IALR1325 was purchased from Shanghai Yubo Biotechnology Co., Ltd.; the sheathed filamentous algae used in the present invention was from Shanghai Guangyu Biotechnology Co., Ltd.;

[0052] Biochar is the waste generated by pruning wetland plants in the riverbank, which is pyrolyzed at high temperature (pyrolysis temperature 600℃) and then crushed. The particle size is 50-300μm and the bulk density is 0.2-0.3g / cm 3 , biochar prepared from other agricultural and forestry wastes or commercially available biochar can also be used;

[0053] The ceramsite is water-treated ceramsite with a particle size of 1 to 2 mm, a cylinder pressure strength of 5 to 10 MPa, and a bulk density of 0.3 to 0.6 g / cm 3 , purchased from Anhui Taoyanyao Environmental Protection Technology Co., Ltd.

[0054] Example 1

[0055] This embodiment provides a microbial carrier material, and the preparation method thereof is as follows:

[0056] The biochar and expanded clay were mixed evenly in a mass ratio of 5:2, and then reacted at 140°C and 5MPa for 8h. After cooling to room temperature, the biochar-expanded clay mixture was mixed evenly with a water-retaining agent, sodium oxalate, in a mass ratio of 7:1 to obtain a carrier material.

[0057] Example 2

[0058] This embodiment provides a fungus culture solution, and the preparation method thereof is as follows:

[0059] Take 50 mL of the filtrate of the activated sludge and mix it with 950 mL of distilled water. After dilution, the total nitrogen concentration is lower than 15 mg / L and the total phosphorus concentration is lower than 1 mg / L. Then put it into a high pressure sterilizer and sterilize it at 121°C for 30 hours. Cool it to room temperature to obtain the fungal culture solution.

[0060] Example 3

[0061] This embodiment provides an algae culture solution, and the preparation method thereof is as follows:

[0062] Take 1.5g NaNO 3 、0.075g MgSO 4 7H 2 O, 0.04g K 2 HPO 4 , 0.036 g CaCl 2 , 0.02gNa 2 CO 3 , 0.02g citric acid, 0.015g ammonium ferric citrate, 0.01g EDTA sodium salt, and 0.01g boric acid are dissolved in 1L deionized water, then put into a high pressure sterilizer, sterilize at 121°C for 30h, and cool to room temperature to obtain algae culture solution.

[0063] Example 4

[0064] This embodiment provides a bacteria-algae mixed solution, and the preparation method thereof is as follows:

[0065] Step 1, inoculating nitrogen-fixing bacteria Azospirillum brasilense and phosphate-dissolving bacteria Pantoea agglomerans IALR1325 into the fungus culture solution prepared in Example 2, and culturing at 25° C. for 72 h to obtain nitrogen-fixing bacteria culture solution and phosphate-dissolving bacteria culture solution, respectively;

[0066] Step 2: inoculate the algae culture solution prepared in Example 3, and culture at 25° C. for 168 h;

[0067] Step 3, centrifuge the culture solution after culturing in step 1 and step 2 at 5000 rpm for 5 min, remove the supernatant and set aside;

[0068] Step 4: Mix the nitrogen-fixing bacteria culture solution, phosphate-dissolving bacteria culture solution, and algae culture solution after centrifugation in step 3 in a volume ratio of 1:1:3, and add 800 mL of uninoculated fungus culture solution and 200 mL of uninoculated algae culture solution to obtain a bacteria-algae mixed solution.

[0069] Example 5

[0070] This embodiment provides a microbial carrier material, and the preparation method thereof is as follows:

[0071] The biochar and expanded clay were mixed evenly in a mass ratio of 2:1, and then reacted at 140°C and 5MPa for 8h. After cooling to room temperature, the biochar-expanded clay mixture was mixed evenly with a water-retaining agent, sodium oxalate, in a mass ratio of 9:1 to obtain a carrier material.

[0072] Example 6

[0073] This embodiment provides a fungus culture solution, and the preparation method thereof is as follows:

[0074] Take 100 mL of activated sludge filtrate and mix it with 900 mL of distilled water. After dilution, the total nitrogen concentration is lower than 15 mg / L and the total phosphorus concentration is lower than 1 mg / L. Then put it into a high pressure sterilizer and sterilize it at 121°C for 30 hours. Cool it to room temperature to obtain the fungal culture solution.

[0075] Example 7

[0076] This embodiment provides a bacteria-algae mixed solution, and the preparation method thereof is as follows:

[0077] Step 1, inoculating nitrogen-fixing bacteria Azospirillum brasilense and phosphate-dissolving bacteria Pantoea agglomerans IALR1325 into the fungus culture solution prepared in Example 6, and culturing at 25° C. for 72 h to obtain nitrogen-fixing bacteria culture solution and phosphate-dissolving bacteria culture solution, respectively;

[0078] Step 2: inoculate the algae culture solution prepared in Example 3, and culture at 25° C. for 168 h;

[0079] Step 3, centrifuge the culture solution after culturing in step 1 and step 2 at 5000 rpm for 5 min, remove the supernatant and set aside;

[0080] Step 4: Mix the nitrogen-fixing bacteria culture solution, phosphate-dissolving bacteria culture solution, and algae culture solution after centrifugation in step 3 in a volume ratio of 1:2:3, and add 800 mL of uninoculated fungus culture solution and 200 mL of uninoculated algae culture solution to obtain a bacteria-algae mixed solution.

[0081] Example 8

[0082] This embodiment provides a microbial carrier material, and the preparation method thereof is as follows:

[0083] The biochar and expanded clay were mixed evenly in a mass ratio of 7:2, and then reacted at 160°C and 6MPa for 10 hours. After cooling to room temperature, the biochar-expanded clay mixture was mixed evenly with a water-retaining agent, sodium oxalate, in a mass ratio of 9:1 to obtain a carrier material.

[0084] Example 9

[0085] This embodiment provides a fungus culture solution, and the preparation method thereof is as follows:

[0086] Take 200 mL of activated sludge filtrate and mix it with 800 mL of distilled water. After dilution, the total nitrogen concentration is lower than 15 mg / L and the total phosphorus concentration is lower than 1 mg / L. Then put it into a high pressure sterilizer and sterilize it at 121°C for 30 hours. Cool it to room temperature to obtain the fungal culture solution.

[0087] Example 10

[0088] This embodiment provides a bacteria-algae mixed solution, and the preparation method thereof is as follows:

[0089] Step 1, inoculating the nitrogen-fixing bacteria Azospirillum brasilense and the phosphate-dissolving bacteria Pantoea agglomerans IALR1325 into the fungus culture solution prepared in Example 10, and culturing at 25° C. for 72 h to obtain the nitrogen-fixing bacteria culture solution and the phosphate-dissolving bacteria culture solution, respectively;

[0090] Step 2: inoculate the algae culture solution prepared in Example 3, and culture at 25° C. for 168 h;

[0091] Step 3, centrifuge the culture solution after culturing in step 1 and step 2 at 5000 rpm for 5 min, remove the supernatant and set aside;

[0092] Step 4: Mix the nitrogen-fixing bacteria culture solution, phosphate-dissolving bacteria culture solution, and algae culture solution after centrifugation in step 3 in a volume ratio of 1:2:3, and add 800 mL of uninoculated fungus culture solution and 200 mL of uninoculated algae culture solution to obtain a bacteria-algae mixed solution.

[0093] Application Example 1

[0094] This application example uses the carrier material prepared in Example 1 and the bacteria-algae mixed solution prepared in Example 4 to construct an ecological slope protection, and the specific steps are as follows:

[0095] S1, applying the carrier material prepared in Example 1 to the surface layer of river soil;

[0096] S2. According to Figure 1 Planting trees (Ailanthus toon, Cinnamomum camphora, Metasequoia), shrubs (Hibiscus), herbs (Vetiver, Reed) and emergent plants (Phragmites australis, Acorus calamus);

[0097] S3, the bacteria-algae mixed solution prepared in Example 4 was heated at 10 mL / min. 2 The spreading amount is evenly sprayed on the surface of the slope protection soil.

[0098] Application Example 2

[0099] This application example uses the carrier material prepared in Example 5 and the bacteria-algae mixed solution prepared in Example 8 to construct an ecological slope protection, and the specific steps are as follows:

[0100] S1, applying the carrier material prepared in Example 5 to the surface layer of the river soil;

[0101] S2. According to Figure 1 Planting trees (Ailanthus toon, Cinnamomum camphora, Metasequoia), shrubs (Hibiscus), herbs (Vetiver, Reed) and emergent plants (Phragmites australis, Calamus);

[0102] S3, the bacteria-algae mixed solution prepared in Example 7 was heated at 10 mL / min. 2 The spreading amount is evenly sprayed on the surface of the slope protection soil.

[0103] Application Example 3

[0104] This application example uses the carrier material prepared in Example 8 and the bacteria-algae mixed solution prepared in Example 10 to construct an ecological slope protection, and the specific steps are as follows:

[0105] S1. Applying the carrier material prepared in Example 8 to the surface of the river soil;

[0106] S2. According to Figure 1 Planting trees (Ailanthus toon, Cinnamomum camphora, Metasequoia), shrubs (Hibiscus), herbs (Vetiver, Reed) and emergent plants (Phragmites australis, Calamus);

[0107] S3, the bacteria-algae mixed solution prepared in Example 10 was heated at 10 mL / min. 2 The spreading amount is evenly sprayed on the surface of the slope protection soil.

[0108] Comparative Example 1

[0109] Based on Application Example 1, the aquatic plants for ecological slope protection were replaced with Metasequoia glyptostroboides and Foxtail Grass, and tap water was used at a rate of 10 mL / m 2 Evenly spray the amount of the solution on the soil surface of the slope protection to replace the bacteria-algae mixture.

[0110] Comparative Example 2

[0111] Based on Application Example 1, the aquatic plants for ecological slope protection were replaced with Metasequoia glyptostroboides and Foxtail Grass, and the fungus culture solution prepared in Example 2 and the algae culture solution prepared in Example 3 were mixed at a volume ratio of 8:2 and heated to 10 mL / m 2 Evenly spray the amount of the solution on the soil surface of the slope protection to replace the bacteria-algae mixture.

[0112] Governance effect:

[0113] Before treatment, samples of the river water were taken and the dissolved oxygen was 3.2 mg / L, the pH was 7, the ammonia nitrogen was 0.88 mg / L, the total nitrogen was 1.43 mg / L, the total phosphorus was 0.15 mg / L, and the five-day biochemical oxygen demand (COD) was 4.9 mg / L.

[0114] The treatment effect of the ecological slope protection after the treatment of the corresponding examples 1 to 3 and the comparative examples 1 and 2 was tested, as shown in the following Table 1:

[0115] Table 1 Pollutant removal ratios of application examples 1 to 3 and comparative examples 1 and 2

[0116] Pollutant removal ratio Application Example 1 Application Example 2 Application Example 3 Comparative Example 1 Comparative Example 2 Ammonia nitrogen / % 67 62 63 26 32 Total nitrogen / % 72 75 73 38 45 Total phosphorus / % 39 48 50 23 29 COD / % 51 49 65 25 31

[0117] It can be seen from Table 1 that the ecological slope protection constructed by application examples 1 to 3 can effectively improve the water quality of the river. The ecological slope protection device is easy to construct and easy to use. While ensuring the reduction of non-point source pollution in the river, it promotes the growth of slope protection plants and realizes the sustainable use of ecological slope protection.

[0118] In summary:

[0119] The present invention establishes a bacterial-algae symbiotic system on the river slope protection, uses a microbial carrier material prepared with biochar and ceramsite as the main raw materials to improve the bulk density and pore structure of the soil, improves the permeability of the soil, and adds a water-retaining agent to increase the moisture content and water holding capacity of the soil, so as to provide a suitable living environment for the bacteria and algae in the soil, so that the bacteria and algae with the ability to purify pollutants in sewage form a biological soil crust on the river slope protection, solving the problem that conventional microorganisms with water purification functions are difficult to survive outside the water body, thereby greatly improving the purification effect of the slope protection vegetation coverage area. At the same time, the metabolic activities of bacteria and algae microorganisms are used to decompose pollutants in sewage and convert them into inorganic substances that can be used by plants, and the root system of the slope protection vegetation can effectively reinforce the river bank soil, and the branches and leaves of the vegetation can block the scouring of the soil by river water and runoff, reduce soil erosion, and effectively control the impact of non-point source pollution on river water quality, and reduce river bank runoff and slope protection erosion.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for constructing an ecological slope protection system based on a bacterial-algal symbiotic system, characterized in that: The steps include: S1, 5 to 8 parts by weight of biochar and 2 to 3 parts by weight of ceramsite are mixed, and then reacted at 120 to 160° C. and 4 to 6 MPa for 8 to 20 hours, cooled to room temperature, 0.1 to 2 parts by weight of a water retaining agent are added and mixed to obtain a microbial carrier material, and then the microbial carrier material is applied to the surface layer of the river slope protection soil; S2. Divide the river bank protection into tree area, shrub area, herbaceous plant area and emergent plant area in the order from far to near the center line of the river channel, and plant trees, shrubs, herbaceous plants and emergent plants in the tree area, shrub area, herbaceous plant area and emergent plant area respectively; S3, spraying the bacteria-algae mixed solution on the surface of the river slope protection soil to form a biological soil crust; the bacteria-algae mixed solution is obtained by mixing a fungus culture solution with an algae culture solution, the fungus culture solution is inoculated with nitrogen-fixing bacteria and phosphate-dissolving bacteria, and the algae culture solution is inoculated with sheath algae; The preparation method of the fungus culture solution is as follows: taking the filtrate of the activated sludge, diluting it with distilled water, putting it into a high pressure sterilizer for sterilization, and cooling it to room temperature to obtain the fungus culture solution; The preparation method of the bacteria-algae mixed solution is as follows: Step 1, inoculating nitrogen-fixing bacteria and phosphate-dissolving bacteria into the fungus culture solution respectively, and culturing at 25° C. for 72 hours to obtain nitrogen-fixing bacteria culture solution and phosphate-dissolving bacteria culture solution respectively; Step 2, inoculating the sheathed filamentous algae into the algae culture solution, and culturing at 25° C. for 168 hours to obtain the sheathed filamentous algae culture solution; Step 3, centrifuging the culture solution of step 1 and step 2 at high speed to remove the supernatant; Step 4: Take the nitrogen-fixing bacteria culture solution and the phosphate-dissolving bacteria culture solution obtained after centrifugation in step 3, and mix them with the sheath algae culture solution obtained in step 2 in proportion to obtain the bacteria-algae mixed solution.

2. The method for constructing an ecological slope protection system based on a bacteria-algae symbiotic system as claimed in claim 1, characterized in that: In step S1, the water retaining agent is sodium oxalate.

3. The method for constructing an ecological slope protection system based on a bacteria-algae symbiotic system as claimed in claim 1, characterized in that: In step S2, the tree includes at least one of Ailanthus toon, Cinnamomum camphora and Metasequoia glyptostroboides, the shrub is Hibiscus, the herbaceous plant includes Vetiver and / or Phragmites australis, and the emergent plant includes Phragmites australis and / or Acorus calamus.

4. The method for constructing an ecological slope protection system based on a bacteria-algae symbiotic system as claimed in claim 1, characterized in that: The raw materials of the algae culture solution include, by weight, 1500 parts of sodium nitrate, 75 parts of magnesium sulfate heptahydrate, 40 parts of dipotassium hydrogen phosphate, 36 parts of calcium chloride, 20 parts of sodium carbonate, 20 parts of citric acid, 15 parts of ammonium ferric citrate, 10 parts of EDTA sodium salt, and 10 parts of boric acid. The algae culture solution is sterilized.

5. The method for constructing an ecological slope protection system based on a bacteria-algae symbiotic system as claimed in claim 1, characterized in that: The activated sludge filtrate is diluted with distilled water to a total nitrogen concentration of less than 15 mg / L and a total phosphorus concentration of less than 1 mg / L.

6. The method for constructing an ecological slope protection system based on a bacteria-algae symbiotic system according to claim 1, characterized in that: In step 4, the nitrogen-fixing bacteria culture solution and the phosphate-dissolving bacteria culture solution are mixed in a volume ratio of 1:(1-3) to obtain a fungus mixture, and then the fungus mixture is mixed with the sheath algae culture solution obtained in step 2 in a volume ratio of (3-5):(1-3) to obtain the bacteria-algae mixture.

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