Efficient emergency treatment and ecological construction method for blue-green algae outbreak in lake

Abstract

The invention discloses an efficient emergency treatment and ecological construction method for lake blue-green algae outbreak, and relates to the technical field of water environment governance, and the method comprises the following steps: constructing an ecological enclosure to isolate a blue-green algae dense area from a surrounding water body; a flocculating agent and an algistat are sequentially added into the ecological enclosure, and emergency treatment is achieved; when the water bloom area or the algae density is reduced to a preset range, comprehensive control over nutritive salt in the water body is carried out, after the water quality reaches a preset requirement, aquatic plant community construction and aquatic animal putting are carried out, and aquatic ecology construction is achieved. According to the method, a comprehensive treatment mode of multiple treatment strategies is fused, water bloom algae in the water body are rapidly removed, meanwhile, long-acting and effective control over eutrophic water body water bloom is achieved, and the method is suitable for being applied and popularized in ecological protection engineering.

Description

Technical Field

[0001] The invention relates to the technical field of water environment treatment, and in particular to a method for efficient emergency treatment and ecological construction of blue algae outbreaks in lakes. Background Art

[0002] In recent years, with the continuous intensification of human activities, the intensity of cyanobacteria blooms in lakes and reservoirs around the world has shown a significant growth trend. In response to this severe challenge, the current cyanobacteria bloom control technology has gradually formed three mainstream methods: physical, chemical and biological. Physical methods, such as mechanical algae removal, hydraulic regulation and ultrasonic treatment, can effectively remove cyanobacteria in water bodies by directly acting on them. Such methods are relatively simple to operate and can quickly respond to cyanobacteria blooms, but they can often only provide short-term relief effects and require high economic costs. Chemical methods focus on using chemical agents to directly kill cyanobacteria, and their significant advantage is that they are quick to take effect. However, the long-term effect of this method is relatively limited. Biological methods use biological or microbial methods to control the growth and reproduction of cyanobacteria, which has the advantages of environmental protection and sustainability, but the implementation cycle is long and the effect may be affected by many factors.

[0003] At present, the control of cyanobacterial blooms relies solely on a single method, which has shown obvious limitations. Therefore, we urgently need to explore and implement a comprehensive control model that integrates multiple control strategies to quickly remove algae blooms in water bodies and achieve long-term and effective control of algae blooms in eutrophic water bodies. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide an efficient emergency treatment and ecological construction method for lake blue algae outbreaks. Through the synergistic effect of multiple methods, the algae blooms in the water body can be quickly removed, and the algae blooms in the eutrophic water body can be effectively and effectively controlled. This not only provides technical support for the restoration and reconstruction of the lake ecosystem, but also provides valuable support and guidance for the technical application and innovation in related fields.

[0005] The technical solution of the present invention is: a method for efficient emergency treatment and ecological construction of lake cyanobacteria outbreaks, comprising:

[0006] Construct ecological enclosures to isolate areas with dense cyanobacteria from surrounding water bodies;

[0007] Add flocculants and algaecides in the ecological enclosure to achieve emergency treatment;

[0008] When the bloom area or algae density is reduced to the preset range, comprehensive control of water nutrients will be carried out. When the water quality reaches the preset requirements, aquatic plant communities will be constructed and aquatic animals will be released to achieve aquatic ecological construction.

[0009] The method of the present invention mainly consists of constructing an ecological enclosure - spreading an algae-controlling ecological agent - controlling water body nutrients, so as to quickly remove algae in the water body and achieve long-term control of algal blooms in eutrophic water bodies. This core method consists of three core steps: first, by accurately positioning and constructing an ecological enclosure, the cyanobacteria-dense area is isolated from the surrounding healthy water body, effectively curbing the further spread of cyanobacteria; then accurately spreading the algae-controlling ecological agent, through the flocculation, algae inhibition and algaecidal components of the agent, the growth and reproduction of cyanobacteria are effectively inhibited, while minimizing the negative impact on the water ecosystem; finally, the water body nutrient control strategy is implemented, and the aquatic ecology is customized and constructed according to the characteristics of lake water quality, reducing the input of nutrients such as nitrogen and phosphorus from the source, and promoting the natural circulation and utilization of nutrients in the water body through ecological means, thereby completely improving the eutrophication of the water body and creating favorable conditions for the comprehensive recovery of the lake ecosystem.

[0010] Preferably, the ecological enclosure includes a plurality of fixed rods inserted into the bottom of the water and an enclosure net, wherein the plurality of fixed rods are arranged at intervals along the edge of the cyanobacteria-dense area, and the enclosure net is arranged around the fixed rods to surround the cyanobacteria-dense area, and the upper end of the enclosure net is provided with a foam strip, and the lower end is provided with a gabion bag with built-in gravel, and the bottom of the enclosure net is provided with counterweights at intervals along the surrounding direction. The foam strip acts as a floating body on the water surface, and the gabion bag is filled with gravel to drop the lower end of the enclosure net onto the bottom mud of the water body.

[0011] Furthermore, the upper and lower ends of the enclosure net are connected to the fixing rods through ropes.

[0012] Preferably, the flocculant is prepared by compounding modified chitosan, kaolin, and polyaluminium chloride in a mass ratio of 1:100-200:20-50, and an algaecide is added 24-48 hours after the flocculant is added, and the algaecide is prepared by compounding algaecide enzymes and algaecide bacteria in a mass ratio of 1:1-10. The principle of compounding modified chitosan, kaolin, and polyaluminium chloride is to form a stable composite system with polyaluminium chloride through interactions such as adsorption and complexation. This composite system may exhibit stronger coagulation, adsorption or catalytic properties than a single component, thereby producing a synergistic effect; the modification method of modified chitosan is to introduce quaternary ammonium groups into chitosan molecules and prepare it through quaternization reaction. The specific preparation method is as follows:

[0013] Disperse 10 g of chitosan in 50 mL of 1 mol / L NaOH solution and stir magnetically for 4 h. Slowly add 10 mL of 1 mol / L 2,3-epoxypropyltrimethylammonium chloride solution under magnetic stirring. After reacting at room temperature for 12 h, wash the mixture in distilled water until the pH value of the washing solution is 7, and dry at 105 °C to obtain modified chitosan.

[0014] The principle of compounding algae-inhibiting enzymes and algae-inhibiting bacteria is that algae-inhibiting enzymes and algae-inhibiting bacteria each have different algae-inhibiting mechanisms, and after compounding, they can complement each other, thereby enhancing the algae-inhibiting effect. Algae-inhibiting enzymes can destroy the algae cell walls, while algae-inhibiting bacteria can secrete algae-inhibiting substances. The combination of the two can more effectively inhibit the growth of algae.

[0015] Furthermore, the algae-inhibiting enzyme solution includes a cellulase solution and a pectinase solution compounded in a volume ratio of 1:1-3, the mass concentration of the cellulase solution is 2%-10%, and the mass concentration of the pectinase solution is 3%-8%; the algae-inhibiting bacteria include Bacillus subtilis, algae-lytic bacteria, and lactic acid bacteria compounded in a mass ratio of 1:1-2:1-4. Bacillus subtilis, algae-lytic bacteria, and lactic acid bacteria are all in powder form. Algae-lytic bacteria can be selected from commercial products or can be made by themselves according to the following steps. Since the homemade raw materials come from the lake to be treated, the algae-lytic bacteria prepared will be more suitable for the water environment to achieve algae-lytic effect:

[0016] The collected eutrophic lake water was diluted by gradient (2-10 times), spread on LB solid plate medium, and cultured at 20-30℃ in dark for 3-5 days. After the colonies grew, single colonies with different morphological characteristics were selected and streaked multiple times to finally obtain pure bacteria;

[0017] Take 1mL of each bacterial liquid and add it to 20mL of algae liquid (commercially available or self-cultivated Chlorella liquid). The strain that can make the algae liquid yellow is the algae-lytic strain. Select the strain with fast algae-lytic effect and high algae-lytic efficiency and cultivate it into bacterial powder to obtain the algae-lytic bacteria.

[0018] Preferably, the dosage of the flocculant and algaecide is determined according to the algae concentration value:

[0019] When 10 million / L≤algae concentration≤50 million / L, the flocculant dosage a is 50g / m 3 ≤a≤100g / m 3 The dosage of algaecide b is 50mL / m 3 ≤b≤100mL / m 3 ;

[0020] When 50 million / L<algae concentration≤100 million / L, the flocculant dosage a is 100g / m 3 <a≤300g / m 3 , the dosage of algaecide b is 100mL / m 3 <b≤200mL / m 3 ;

[0021] When the algae concentration is greater than 100 million / L, the flocculant dosage a is greater than 300g / m 3 , dosage of algaecide b>200mL / m 3 .

[0022] Preferably, when the algal bloom area ratio is less than 10% of the water area or the algae density is less than 10 million / L, comprehensive control of water body nutrients is carried out, and the comprehensive control of water body nutrients includes:

[0023] Add denitrifying bacteria activation liquid gradually until the total nitrogen in the water meets TN≤2mg / L;

[0024] Then gradually apply phosphorus-locking agents until the total phosphorus TP in the water is ≤0.4mg / L;

[0025] Observe the water transparency, and wait until the transparency reaches 1-3 times greater than the water depth and the water quality meets the preset requirements.

[0026] Furthermore, the preparation method of the denitrifying bacteria agent activation liquid comprises: forming a mixed liquid with the denitrifying bacteria agent and lake water at a mass ratio of 1:20-40, adding 1000-4000 ppm of flour, 120-300 ppm of urea, and 30-60 ppm of potassium dihydrogen phosphate to the mixed liquid according to mass concentration, introducing air, and exposing for 2-4 hours to obtain the denitrifying bacteria agent activation liquid;

[0027] The dosing method of denitrifying bacteria activation liquid includes: the single dosing amount of denitrifying bacteria activation liquid is 50-100mL / m 3 And the total nitrogen TN was tested on the 3rd-4th day after each addition. If TN ≤ 2mg / L, the addition was stopped. If TN > 2mg / L, the addition was continued until TN ≤ 2mg / L.

[0028] In the denitrifying bacteria activation liquid, flour is used as a carbon source, urea is used as a nitrogen source, potassium dihydrogen phosphate is used as a phosphorus source and a potassium source, and air is introduced for ventilating to provide sufficient oxygen. In the present invention, the denitrifying bacteria is a commercially available product, such as the nitrification and denitrification biological bacteria of Aladdin Environmental Technology Company.

[0029] Furthermore, the phosphorus-locking agent is a natural mineral loaded with free lanthanum, and the phosphorus-locking agent is added in a manner including: a single addition amount of the phosphorus-locking agent is 10-20 g / m 3 And the total phosphorus TP is detected on the 3rd to 4th day after each addition. If TP≤0.4mg / L, the addition is stopped. If TP>0.4mg / L, the addition is continued until the total phosphorus TP≤0.4mg / L. Furthermore, during the addition, the phosphorus locking agent is mixed with lake water in a mass ratio of 1:10-15 and then sprayed on the lake surface. In the present invention, the phosphorus locking agent is a commercially available product, such as the Australian Phoslock phosphorus locking agent.

[0030] Preferably, the type of aquatic plants is determined according to the water depth, specifically including: planting emergent plants when the water depth is less than 50 cm, planting submerged plants when the water depth is 50-100 cm, and planting floating leaf plants when the water depth is greater than 100 cm.

[0031] Preferably, the aquatic animals are released including: filter-feeding fish are released when the aquatic plants grow for 1-2 months, omnivorous fish are released when the aquatic plants grow for 3-4 months, and herbivorous fish are released after the aquatic plants grow for 4 months;

[0032] The dosage for filter-feeding fish is 30-60g / m 2 ; The dosage for omnivorous fish is 10-20g / m 2 ; The dosage for herbivorous fish is 20-50g / m 2 .

[0033] The beneficial effects of the present invention are:

[0034] 1. The present invention innovatively integrates the strategies of ecological enclosure construction, precise application of algae control ecological agents and comprehensive control of water nutrients to implement comprehensive and systematic management of cyanobacteria blooms. This method cleverly combines the three advantages of direct physical isolation, rapid chemical inhibition and sustainability of biological regulation. The various means support and synergize each other, thus directly attacking the root cause of cyanobacteria blooms, achieving effective control of cyanobacteria and significant restoration of water ecological balance.

[0035] 2. Using ecological enclosures to replace traditional mechanical algae removal, hydraulic regulation and ultrasonic treatment can prevent the further growth and spread of algae in the enclosure, and prevent the exchange of materials, energy and information between the lakeshore and the inner lake system. At the same time, a certain closed space is formed in the enclosure, which can concentrate the algae in the water body. And the size of the enclosure can be adjusted in time according to the range of algae growth to achieve the purpose of precise algae control.

[0036] 3. Algae control ecological agents are mainly composed of flocculants and algaecides. First, the role of spreading flocculants is to flocculate and precipitate the algae in the water into the surface mud. Then, spreading algaecides can inhibit the photosynthesis of the precipitated algae, slow down or inhibit the growth and reproduction of algae, and cause the algae to die in the surface mud.

[0037] 4. Comprehensive control of water nutrients First, by spreading denitrifying bacteria and ecological phosphorus-locking agents, the concentration of nitrogen and phosphorus nutrients in the enclosure is reduced to create unfavorable conditions for algae growth. Then, the aquatic ecosystem is constructed or restored, such as planting aquatic plants and releasing filter-feeding fish, to further improve the self-purification capacity of the water body and form a long-term inhibitory effect on algae growth.

[0038] 5. The present invention integrates a comprehensive management model of multiple management strategies, quickly removes algae blooms in water bodies, and simultaneously achieves long-term and effective control of algae blooms in eutrophic water bodies. It is suitable for promotion and application in ecological protection projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art description will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 Schematic diagram of the ecological enclosure structure of the present invention

[0041] Among them: 1-fixed pole 2-enclosure net 3-foam strip 4-gabion bag 5-counterweight block 6-bottom mud 10-ecological enclosure. DETAILED DESCRIPTION

[0042] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application. Unless otherwise specified, various raw materials and equipment used in the present application can be purchased from the market or can be prepared by existing methods. The following specific embodiments further describe the present invention in detail.

[0043] In view of the obvious limitations of the existing single method for treating blue algae blooms, the present invention provides a comprehensive treatment model that integrates multiple treatment strategies. Through the synergistic effect of multiple methods, the algae blooms in the water body can be quickly removed, while achieving long-term and effective control of the blooms in eutrophic water bodies. This not only provides technical support for the restoration and reconstruction of lake ecosystems, but also provides valuable support and guidance for technical applications and innovations in related fields.

[0044] The method of the present invention includes ecological enclosure construction, algae control ecological agent spraying and water body nutrient salt control. The ecological enclosure construction can effectively isolate the blue algae area to prevent its spread; the algae control ecological agent spraying can quickly inhibit the growth of blue algae and promote the restoration of the ecological balance of the water body; the water body nutrient salt control can fundamentally reduce the nutrients required for the reproduction of blue algae and reduce the risk of blue algae blooms. This comprehensive management method has the advantages of fast effect, long duration, low comprehensive cost and high safety factor, and is suitable for the management of water bodies of different sizes and types.

[0045] The present invention provides a method for efficient emergency treatment and ecological construction of lake blue algae outbreaks, comprising the following steps:

[0046] Step 1: Build an ecological enclosure to isolate the cyanobacteria-dense area from the surrounding water.

[0047] When a cyanobacteria bloom breaks out in a local area or its density increases rapidly (the bloom area is greater than 10% of the water area or the algae density is greater than 10 million / L), especially in summer (the peak period of cyanobacteria bloom), emergency measures should be taken before the cyanobacteria gather in large numbers in the area to prevent secondary disasters. By constructing ecological enclosures10 to isolate the shore of the lake, the algae in the water are confined within a certain range to prevent further growth and spread, while blocking the exchange of materials, energy and information flows between the lakeshore and the inner lake system. Carrying out fish removal before isolation can reduce the disturbance of fish to sediments and inhibit endogenous release.

[0048] Ecological enclosure 10 structure such as Figure 1 As shown, it includes a plurality of fixed poles 1 inserted into the bottom of the water and a fence net 2. The plurality of fixed poles 1 are arranged at intervals along the edge of the cyanobacteria-dense area. The lower ends of the fixed poles 1 are inserted into the bottom mud 6. The fence net 2 is arranged around the fixed poles 1 to surround the cyanobacteria-dense area. The upper end of the fence net 2 is provided with a foam strip 3, and the lower end is provided with a gabion bag 4 with built-in gravel. Counterweights 5 are arranged at intervals along the surrounding direction at the bottom of the fence net 2. The gabion bag 4 and the counterweight 5 both function to make the lower end of the fence net 2 fall onto the bottom mud 6 due to gravity, so that the fence net 2 forms a complete circle along all the fixed poles 1. The cyanobacteria-dense area enclosed by the ecological fence 10 is determined according to actual needs, and the shape is not limited. It can be square, circular, polygonal, or even a ring along the entire lakeside. Figure 1 The square ecological enclosure 10 is only a specific example to show the structure clearly. Figure 1 The other three sides of the middle partition net 2 are drawn in an abbreviated manner.

[0049] The enclosure net 2, such as a mesh cloth, a mesh plastic plate, a wire mesh, etc., is installed on the water surface and fixed on the ground or the shore to form a certain closed space, and the algae in the water body are guided to this area for centralized treatment. The enclosure net 2 is installed on the water surface through the fixing rod 1 to form a certain closed space, and the algae in the water body can be guided to this area for centralized treatment. In some preferred embodiments, the enclosure net 2 is a PVC mesh cloth.

[0050] The construction method of the ecological enclosure 10 is as follows: first determine the cyanobacteria-dense area; prefabricate the enclosure net 2 on the shore, that is, set a cylindrical cut-angle dense foam strip 3 at the upper end of the enclosure net 2 as a water surface float, the length direction of the foam strip 3 is consistent with the extension direction of the enclosure net 2 and is arranged at intervals along the extension direction of the enclosure net 2, and the stone cage bag 4 at the lower end of the enclosure net 2 is filled with gravel and the counterweight block 5 is arranged at intervals along the extension direction at the bottom of the enclosure net 2; along the edge of the determined cyanobacteria-dense area, the fixed rod 1 is arranged at intervals, and the bottom of the fixed rod 1 is inserted into the bottom mud 6; finally, the prefabricated enclosure net 2 on the shore is surrounded along all the fixed rods 1 in a full circle to surround the cyanobacteria-dense area. The upper and lower ends of the enclosure net 2 are connected to each fixed rod 1 by ropes to ensure the overall stability of the enclosure. At this time, the foam strip 3 floats on the water surface, and the stone cage bag 4 and the counterweight block 5 ensure that the lower end of the enclosure net 2 falls on the bottom mud 6, so as to isolate the cyanobacteria-dense area from the surrounding water body.

[0051] Step 2: Add flocculants and algaecides into the ecological enclosure to achieve emergency treatment.

[0052] After the ecological enclosure 10 is built, the flocculant is accurately added. The flocculant can quickly and effectively aggregate the algae floating in the water and flocculate them onto the surface mud to achieve the physical sedimentation of the algae. Subsequently, the algaecide is applied. The algaecide, with its unique biological activity interfering with the metabolism of algae cells and the competitive inhibition effect of algaecide bacteria, synergistically acts on the settled algae, significantly inhibiting its photosynthesis ability, thereby slowing down or even terminating its growth and reproduction cycle, and ultimately causing the algae to die naturally in the surface mud.

[0053] The flocculant is prepared by compounding modified chitosan, kaolin, and polyaluminium chloride (PAC) in a mass ratio of 1:100-200:20-50. The modified chitosan is prepared by introducing quaternary ammonium groups into the chitosan molecules through a quaternization reaction. The specific preparation method is as follows:

[0054] 10g of chitosan was dispersed in 50mL of 1mol / L NaOH solution and stirred magnetically for 4h; 10mL of 1mol / L 2,3-epoxypropyltrimethylammonium chloride solution was slowly added to the chitosan dispersion under magnetic stirring. After reacting at room temperature for 12h, the mixed system was washed in distilled water until the pH value of the washing solution was 7, and dried at 105°C to obtain modified chitosan.

[0055] The dosage of flocculant is determined according to the algae concentration value.

[0056] The algaecide is added 24-48 hours after the flocculant is added. The algaecide is obtained by compounding the algaecide enzyme and the algaecide bacteria in a mass ratio of 1:1-10. The dosage is determined according to the algae concentration value, as shown in Table 1 below (the unit of flocculant dosage is g / m 3 The unit of algaecide dosage is mL / m3 , all refer to every 1m 3 (volume dosage of water in the enclosed cyanobacteria-dense area).

[0057] Table 1 Flocculant and algaecide dosage

[0058]

[0059] The algae-inhibiting enzyme is obtained by compounding a cellulase solution with a mass concentration of 2%-10% and a pectinase with a mass concentration of 3%-8% according to a volume ratio of 1:1-3; the algae-inhibiting bacteria are obtained by compounding Bacillus subtilis, algae-lytic bacteria and lactic acid bacteria according to a volume ratio of 1:1-2:1-4.

[0060] The algicidal bacteria are prepared according to the following steps:

[0061] The collected eutrophic lake water was diluted by gradient (2-10 times), spread on LB solid plate medium, and cultured at 20-30℃ in dark for 3-5 days. After the colonies grew, single colonies with different morphological characteristics were selected and streaked multiple times to finally obtain pure bacteria;

[0062] Take 1mL of each bacterial liquid and add it to 20mL of algae liquid (commercially available or self-cultivated Chlorella liquid). The strain that can make the algae liquid yellow is the algae-lytic strain. Select the strain with fast algae-lytic effect and high algae-lytic efficiency and cultivate it into bacterial powder to obtain the algae-lytic bacteria.

[0063] Step 3: When the bloom area or algae density is reduced to the preset range, carry out comprehensive control of water nutrients. When the water quality reaches the preset requirements, construct aquatic plant communities and release aquatic animals to achieve aquatic ecological construction.

[0064] After step 2 is completed, when the proportion of algal bloom area is less than 10% of the water area or the algae density is less than 10 million / L, comprehensive control of water nutrients should be carried out in a timely manner. Comprehensive control of water nutrients includes:

[0065] Add denitrifying bacteria activation liquid gradually until the total nitrogen in the water meets TN≤2mg / L;

[0066] Then add phosphorus lock agent gradually until the total phosphorus TP in the water is ≤0.4mg / L;

[0067] Observe the water transparency, and wait until the transparency reaches 1-3 times greater than the water depth and the water quality meets the preset requirements.

[0068] The preparation method of denitrifying bacteria activation liquid includes: forming a mixed liquid with denitrifying bacteria and lake water at a mass ratio of 1:20-40, adding 1000-4000ppm of flour, 120-300ppm of urea, and 30-60ppm of potassium dihydrogen phosphate to the mixed liquid according to mass concentration, introducing air, and exposing for 2-4 hours to obtain the denitrifying bacteria activation liquid. The addition method of denitrifying bacteria activation liquid includes: spraying, with a single addition amount of 50-100mL / m 3 And after each addition, the total nitrogen TN is tested on the 3rd to 4th day. If TN ≤ 2mg / L, the addition is stopped. If TN > 2mg / L, the addition is continued until TN ≤ 2mg / L. In some preferred embodiments, the total addition amount of the denitrifying bacteria activation liquid is controlled at 300-500ml / m 3 .

[0069] The phosphorus-locking agent is a natural mineral loaded with free lanthanum (0.01 mg / L < free lanthanum < 0.1 mg / L). The phosphorus-locking agent is added in the following ways: the phosphorus-locking agent is mixed with lake water in a ratio of 1:10-15 and then sprayed on the lake surface. The single dosage of the phosphorus-locking agent is 10-20 g / m 3 And the total phosphorus TP was tested on the 3rd to 4th day after each addition. If TP≤0.4mg / L, the addition was stopped. If TP>0.4mg / L, the addition was continued until the total phosphorus TP≤0.4mg / L.

[0070] Through the above application of denitrifying bacteria, ecological phosphorus-locking agents (the dosage unit of denitrifying bacteria activation liquid is mL / m 3 The unit of dosage of phosphorus lock agent is g / m 3 , all refer to every 1m 3 The amount of water added to the enclosed blue algae-dense area) can effectively reduce the content of nitrogen and phosphorus nutrients in the water (total phosphorus in the water ≤ 0.4 mg / L, total nitrogen ≤ 2 mg / L) and control the growth of algae. After the nitrogen and phosphorus meet the requirements, observe the transparency of the water body. When the transparency reaches 1-3 times the transparency greater than the water depth, the aquatic plant community can be constructed. Generally, the transparency can meet the requirements within no more than 10 days. When the transparency is insufficient, preliminary experiments should be carried out in different areas according to the transparency of the water body, analyze the single dosage and cumulative dosage, and conduct transparency tests every day after spraying.

[0071] In the construction of aquatic plant communities, aquatic plants are generally selected from local species, while a small amount of foreign species are added to enhance the ability of lake ecosystems to adapt to changes in the surrounding environment. After the construction of aquatic plant communities is completed, filter-feeding fish can be released in the early stage (1-2 months) to control the outbreak of blue-green algae blooms through the feeding of filter-feeding fish such as silver carp and bighead carp on phytoplankton; omnivorous fish are released in the medium term (3-4 months) to extend the food chain and increase the stability of the aquatic ecosystem. Herbivorous fish are released in the later stage (after 4 months) to regulate the biomass of aquatic plants. Through the optimization and regulation of the later system, a healthy food web is formed to achieve long-term health and stability of the ecosystem.

[0072] In the area where aquatic plant communities are constructed, emergent plants are planted when the water depth is less than 50 cm, submerged plants are planted when the water depth is 50-100 cm, and floating leaf plants are planted when the water depth is greater than 100 cm.

[0073] The dosage for filter-feeding fish is 30-60g / m 2 ; The dosage for omnivorous fish is 10-20g / m 2 ; The dosage for herbivorous fish is 20-50g / m 2 (g / m 2 Refers to every 1m 2 (dosage per area of ​​the enclosed cyanobacteria-dense area).

[0074] The present application is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0075] Example 1

[0076] Taking a lake in Wuhan as an example, when the algae density was detected to be 45 million / L in a local area (water depth <1m), efficient emergency treatment of the blue-green algae outbreak was carried out.

[0077] Step 1: Build an ecological enclosure to isolate the cyanobacteria-dense area from the surrounding water.

[0078] First, use GPS to locate the location of the ecological enclosure 10, and use wooden stakes or bamboo to mark the location. The positioning points are 10-50m apart to ensure that the enclosure net 2 is straight. The enclosure net 2 is a PVC cloth with a height of 3m. The upper end is provided with a water surface floating body cylindrical cut corners of encrypted foam strips 3 along the length direction. The length of each foam strip 3 is 110cm and the diameter is 30cm. The enclosure net 2 is made on the shore. The lower part of the enclosure net 2 is provided with a 15cm diameter gabion bag 4, which is filled with gravel. A 30cm×30cm×30cm cement block is used as a counterweight 5 at the connection between each 100m enclosure. Carrying out fish removal before isolation can reduce the disturbance of fish to sediments and inhibit endogenous release. Finally, according to the previous marked position, a D80×6m galvanized steel pipe is fixed underwater as a fixed rod 1, and the manufactured enclosure net 2 is connected to the fixed rod 1 with a 16mm PVC rope to ensure the overall stability of the ecological enclosure 10.

[0079] Step 2: Add flocculants and algaecides into the ecological enclosure to achieve emergency treatment.

[0080] After the ecological enclosure 10 is built, the flocculant is dissolved according to the ratio (modified chitosan, kaolin, polyaluminium chloride according to the mass ratio of 1:100:20), and then it is sprayed manually with a pump at a spraying amount of 90g / m 3 During spraying, avoid the pump head directly hitting the water surface, and the upward angle is about 60°. After spraying, the algae concentration in the lake is tested every 3 hours to achieve an algae concentration of less than 10 million (pieces / L). If it is unstable, re-spray in time. Add the algaecide 30 hours after the flocculant is added. Add the algaecide (the algaecide is prepared by compounding a 4% mass concentration cellulase solution and a 4% mass concentration pectinase solution in a volume ratio of 1:1. The cellulase solution and the pectinase solution are prepared according to conventional methods in the art; the algaecide is prepared by compounding Bacillus subtilis, algae-lytic bacteria, and lactic acid bacteria in a mass ratio of 1:1:1; the mass ratio of algaecide to algaecide is 1:1) at a dosage of 90mL / m 3 Carry out manual spraying in the same way as flocculants.

[0081] Step 3: When the bloom area or algae density is reduced to the preset range, carry out comprehensive control of water nutrients. When the water quality reaches the preset requirements, construct aquatic plant communities and release aquatic animals to achieve aquatic ecological construction.

[0082] After the algae inhibitor is applied, when the proportion of algae bloom area is less than 10% of the water area or the algae density is less than 10 million / L, comprehensive control of water nutrients is carried out. Powdered composite microbial agents are used for water denitrification. The microbial powder is activated before use. The activation method is: mix the strain and lake water at a mass ratio of 1:40, add 1000ppm flour, 120ppm urea, and 30ppm potassium dihydrogen phosphate, let in air, and expose for 2-4 hours to obtain the denitrification agent activation liquid.

[0083] According to the total nitrogen pollution of the water body, denitrification bacteria activation liquid is added gradually, with a single dosage of 100mL / m 3 After spraying, the total nitrogen test is performed every three days to test the treatment effect. When the total nitrogen is ≤2mg / L, the addition is terminated. The cumulative addition amount in this embodiment is about 400mL / m 3 .

[0084] When the total nitrogen in the water is ≤2mg / L, sprinkle the phosphorus-locking agent into the water body one by one, with a single dosage of 10g / m 3 After spreading, the total phosphorus test is performed every three days to test the treatment effect until the total phosphorus is ≤0.4mg / L. The cumulative amount added in this embodiment is 50g / m 3 The phosphorus-locking agent is mixed with water at a mass ratio of 1:10 through the water inlet pump. After mixing, the phosphorus-locking agent is dispersed into slurry, and the phosphorus-locking agent slurry is evenly sprayed on the surface of the lake through the water outlet pump connected to the spraying pipe.

[0085] After spreading the phosphorus-locking agent, observe the water transparency. On the 10th day, when the water transparency is 1.5 times greater than the water depth, the aquatic plants can be restored.

[0086] In this embodiment, since the water depth is 0.5m<water depth<1m, submerged plants are selected as aquatic plants, namely the local species Vallisneria, Water Chestnut and Foxtail Algae, and a small amount of the foreign species Potamogeton australis are used to enhance the ability of the lake ecosystem to adapt to changes in the surrounding environment. Aquatic plants are pretreated before planting: cleaning, sorting, removing impurities and injured, disabled, diseased and missing plants, and pre-treating with ovicides (killing fish eggs, snail eggs), sterilizers (killing bacterial pathogens, mold, pests and diseases, etc.), root promoters, growth promoters, etc. The submerged plants are planted using the mud bag throwing method. Select soil with greater viscosity, completely wrap the seeds and spores of the plants in the soil, and slowly throw them into the water. When the plants have grown for 2 months, according to 40g / m 2 Bighead carp (filter-feeding fish) was added, and when the plants were 3 months old, the water content was 10 g / m 2 Culter alba (omnivorous fish) was released, and after the plants grew for 4 months, the water content was 20g / m 2 Release grass carp (i.e. herbivorous fish).

[0087] The treatment effect of this embodiment is shown in Table 2 below.

[0088] Table 2 Data before and after treatment

[0089]

[0090] It can be seen from Table 2 above that after the addition of flocculants and algaecides, the algae concentration dropped to 8.32 million / L; after the addition of denitrifying bacteria and phosphorus-locking agents, the total phosphorus in the water body was ≤0.4 mg / L and the total nitrogen was ≤2 mg / L; 60 days after the planting of submerged plants, the plant coverage reached 78%, and 30 days after all fish were released, the algae concentration was only 5.84 million / L, and the plant coverage reached 80%, realizing the construction of aquatic ecology.

Claims

1. A method for efficient emergency treatment and ecological construction of lake blue algae outbreaks, characterized in that: include: Construct ecological enclosures to isolate areas with dense cyanobacteria from surrounding water bodies; Add flocculants and algaecides in the ecological enclosure to achieve emergency treatment; When the bloom area or algae density is reduced to the preset range, comprehensive control of water nutrients will be carried out. When the water quality reaches the preset requirements, aquatic plant communities will be constructed and aquatic animals will be released to achieve aquatic ecological construction.

2. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 1, characterized in that: The ecological enclosure comprises a plurality of fixed rods (1) inserted into the bottom of the water and an enclosure net (2); the plurality of fixed rods (1) are arranged at intervals along the edge of a densely populated area of ​​blue algae; the enclosure net (2) is arranged around the fixed rods (1) to surround the densely populated area of ​​blue algae; a foam strip (3) is provided at the upper end of the enclosure net (2) and a gabion bag (4) with internal gravel is provided at the lower end; and counterweight blocks (5) are provided at intervals along the length direction at the bottom of the enclosure net (2).

3. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 1, characterized in that: The flocculant is prepared by compounding modified chitosan, kaolin and polyaluminium chloride in a mass ratio of 1:100-200:20-50. The algaecide is added 24-48 hours after the flocculant is added. The algaecide is prepared by compounding algaecide enzyme and algaecide bacteria in a mass ratio of 1:1-10.

4. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 3, characterized in that: The algae-inhibiting enzyme comprises a cellulase solution and a pectinase solution compounded in a volume ratio of 1:1-3, wherein the mass concentration of the cellulase solution is 2%-10%, and the mass concentration of the pectinase solution is 3%-8%; the algae-inhibiting bacteria comprises Bacillus subtilis, algae-lytic bacteria, and lactic acid bacteria compounded in a mass ratio of 1:1-2:1-4.

5. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 1, characterized in that: The dosage of the flocculant and algaecide is determined according to the algae concentration value: When 10 million / L≤algae concentration≤50 million / L, the flocculant dosage a is 50g / m 3 ≤a≤100g / m 3 The dosage of algaecide b is 50mL / m 3 ≤b≤100mL / m 3 ; When 50 million / L<algae concentration≤100 million / L, the flocculant dosage a is 100g / m 3 <a≤300g / m 3 , the dosage of algaecide b is 100mL / m 3 <b≤200mL / m 3 ; When the algae concentration is greater than 100 million / L, the flocculant dosage a is greater than 300g / m 3 , dosage of algaecide b>200mL / m 3 .

6. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 1, characterized in that: When the algal bloom area ratio is less than 10% of the water area or the algae density is less than 10 million / L, comprehensive control of water nutrients is carried out. The comprehensive control of water nutrients includes: Add denitrifying bacteria activation liquid gradually until the total nitrogen in the water meets TN≤2mg / L; Then add phosphorus lock agent gradually until the total phosphorus TP in the water is ≤0.4mg / L; Observe the water transparency, and wait until the transparency reaches 1-3 times greater than the water depth and the water quality meets the preset requirements.

7. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 6, characterized in that: The preparation method of the denitrifying bacteria agent activation liquid comprises: forming a mixed liquid with the denitrifying bacteria agent and lake water at a mass ratio of 1:20-40, adding 1000-4000 ppm of flour, 120-300 ppm of urea, and 30-60 ppm of potassium dihydrogen phosphate to the mixed liquid according to mass concentration, introducing air, and exposing for 2-4 hours to obtain the denitrifying bacteria agent activation liquid; The dosing method of denitrifying bacteria activation liquid includes: the single dosing amount of denitrifying bacteria activation liquid is 50-100mL / m 3 And the total nitrogen TN was tested on the 3rd-4th day after each addition. If TN ≤ 2mg / L, the addition was stopped. If TN > 2mg / L, the addition was continued until TN ≤ 2mg / L.

8. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 6, characterized in that: The phosphorus-locking agent is a natural mineral loaded with free lanthanum. The phosphorus-locking agent is added in the following ways: a single addition amount of the phosphorus-locking agent is 10-20 g / m 3 And the total phosphorus TP was tested on the 3rd to 4th day after each addition. If TP≤0.4mg / L, the addition was stopped. If TP>0.4mg / L, the addition was continued until the total phosphorus TP≤0.4mg / L.

9. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 1, characterized in that: The types of aquatic plants are determined according to the water depth, specifically including: planting emergent plants when the water depth is less than 50cm, planting submerged plants when the water depth is 50-100cm, and planting floating leaf plants when the water depth is greater than 100cm.

10. The method for efficient emergency treatment and ecological construction of lake blue algae outbreaks according to claim 1, characterized in that: The release of aquatic animals includes: filter-feeding fish when the aquatic plants grow for 1-2 months, omnivorous fish when the aquatic plants grow for 3-4 months, and herbivorous fish after the aquatic plants grow for 4 months; The dosage for filter-feeding fish is 30-60g / m 2 ; The dosage for omnivorous fish is 10-20g / m 2 ; The dosage for herbivorous fish is 20-50g / m 2 .

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