A substrate conditioner for multi-pond wetlands and its preparation method

Abstract

The present invention provides a substrate conditioner for a multi-pond wetland and a preparation method thereof, which relates to the technical field of the restoration of the substrate ecosystem of a multi-pond wetland. The substrate conditioner is prepared with an inorganic porous carrier as the shell layer, bacterial strains as the intermediate layer, and plant seeds as the core layer. The intermediate layer is a coating structure in which different bacterial strains are distributed in different coating layers. The preparation method includes the following steps: S1. Seed activation; S2. Bacterial strain cultivation; S3. Core layer preparation; S4. Bacterial strain intermediate layer preparation; S5. Outer layer preparation. The conditioner prepared by the present invention can not only clarify the water body and reduce the suspended matter in the water body, but also improve the substrate of the multi-pond wetland, reduce the organic matter content in the bottom mud, and is beneficial to the restoration of the submerged plant ecosystem. After the submerged plants grow, the multi-pond wetland can also be used for the advanced ecological purification of the tail water from a sewage treatment plant.

Description

Technical Field

[0001] The present invention relates to the technical field of the restoration of the substrate ecosystem of multi-pond wetlands, and specifically relates to a substrate conditioner for multi-pond wetlands and a preparation method thereof. Background Art

[0002] Submerged plants and pond sediment are part of the multi-pond wetland ecosystem. Among them, pond sediment is mainly composed of feed residues, fish feces, dead algae, soil, and microorganisms. After long-term aquaculture in the pond, a large amount of nitrogen, phosphorus, and organic matter have accumulated in the pond sediment. The accumulation of a large amount of organic matter has polluted the pond sediment. On the one hand, the polluted sediment will form a large amount of suspended matter and dissolved organic carbon (DOC), resulting in turbid water and greatly affecting the transparency, which has a great impact on the water quality of multi-pond wetlands. At the same time, the polluted sediment is also not conducive to the growth of submerged plants and benthic animals, leading to the death of submerged plants and benthic animals and further damaging the submerged plant ecosystem in the pond. On the other hand, the polluted sediment forms an anaerobic environment at the sediment-water interface layer, causing the diffusion of toxic products of microorganisms into the water, changing the pH of the water, and further increasing the content of N, P, etc., further damaging the submerged plant ecosystem.

[0003] Pond sediment is divided into four interfaces. The first interface is the contact surface between the sediment and the water, mainly the inflow of natural nutrients, pond organisms, digestive residues, the loss of artificial feed, the waste excreted by cultured animals, and substances added during aquaculture. This layer also contains a large amount of organic matter and harmful substances. The second interface is the sediment and silt deposition surface, that is, a cross-section of 5 - 10 cm, mainly the sediment layer of pond bottom silt, which is the normal depth during pond aquaculture. Microbial activities are frequent within this depth, and the physical and chemical properties are extremely special, which is the most important part determining the quality of the substrate. The third interface is the surface soil layer of the initial accumulation layer at the bottom. The fourth interface is the deep and original soil layer.

[0004] The organic matter in the sediment refers to the general term of carbon-containing organic compounds in the sediment, that is, organic carbon. Organic matter is one of the important components of sediment and is also the main symbol of the formation of the original sediment. With the continuation of aquaculture in the aquaculture pond, the proportion of organic matter content in the sediment increases. The accumulation of these organic matters mainly comes from feed residues, fish and shrimp feces, and the residues of algae and microorganisms. The organic matter in the sediment has a buffering effect on the acidity and alkalinity of the sediment, making the bottom not easily become acidic. Therefore, a bottom with an appropriate amount of organic matter in the sediment is necessary for a good pond.

[0005] At present, the most commonly used method for bottom improvement is to use biological agents, which can improve the pond bottom environment. The commonly used biological agents are mainly microorganisms and algae, including microbial agents, photosynthetic bacteria, Bacillus subtilis, etc. Applying biological agents can promote the decomposition and utilization of bottom organic matter, improve water quality, and enhance the immunity of fish. At the same time, biological agents can also inhibit the growth and reproduction of pathogenic bacteria and prevent the occurrence of diseases. However, at present, when using biological agents, they are generally directly sprinkled to make them contact with the bottom mud. Since the living environments of microorganisms in different biological agents are different and the required nutrients are different, different microorganisms compete with each other or cannot adapt to the bottom mud environment, resulting in the need for a large amount of biological agents to improve the bottom mud environment, leading to a large dosage, a long recovery period, and an unsatisfactory improvement result for the bottom mud environment. Summary of the Invention

[0006] (1) Technical problems to be solved

[0007] In view of the deficiencies of the prior art, the present invention provides a bottom quality improver for multi-pond wetlands and its preparation method, which solves the problems of large dosage of existing improvers and poor improvement effect on the bottom mud environment.

[0008] (2) Technical solutions

[0009] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0010] A bottom quality improver for multi-pond wetlands, specifically including: the bottom quality improver is prepared with an inorganic porous carrier as the shell layer, bacterial strains as the intermediate layer, and plant seeds as the core layer, and the intermediate layer is a coating structure in which different bacterial strains are distributed in different coating layers.

[0011] Preferably, the bottom quality improver includes, by weight: 10-30 parts of inorganic porous carrier, 5-10 parts of bacterial strains, and 2-5 parts of plant seeds.

[0012] Preferably, the inorganic porous carrier is one or a combination of diatomite, zeolite, activated carbon, porous alumina, porous ceramics, etc.

[0013] Preferably, the bacterial strains are one or a combination of photosynthetic bacteria, yeast, Bacillus subtilis, nitrifying bacteria, cyanobacteria, lactic acid bacteria, EM bacteria, etc.

[0014] Preferably, the plant seeds are one or a combination of Potamogeton crispus seeds, Vallisneria natans seeds, Hydrilla verticillata seeds, Ceratophyllum demersum seeds, Myriophyllum verticillatum seeds, Potamogeton distinctus seeds, etc.

[0015] Preferably, the plant seeds are Potamogeton crispus seeds.

[0016] Water Chestnut is a perennial submerged herb of the Potamogeton family. It has a strong adaptability to eutrophication of water bodies, can naturally reproduce by stone buds, can also be propagated by cuttings, and can absorb N, P and metal ions in the water. By selecting water chestnut seeds, it can not only adapt to the newly improved bottom mud environment, but also further regulate N and P in the water body. At the same time, it can also provide help for the subsequent treatment of tail water from the sewage treatment plant in the pond.

[0017] A method for preparing a multi-pond wetland substrate improver comprises the following steps:

[0018] S1. Seed activation:

[0019] Soak the plant seeds for 1 to 3 hours, then add plant regulators, soak for 20 to 30 minutes, remove and dry;

[0020] S2. Bacteria culture:

[0021] Different strains were cultured on different solid culture media for 24 to 48 hours, and then collected separately after they adhered to the wall.

[0022] S3. Nuclear layer preparation:

[0023] The plant seeds obtained in step S1 are placed in clean water, chitosan solution and microbial gelling agent are added, the mixture is allowed to stand for a while, and then stirred to react to form a gel, which is freeze-dried at low temperature for later use;

[0024] S4. Preparation of the intermediate layer of bacterial strains:

[0025] The gel formed in step S3 is placed in a nutrient suspension, and the first bacterial species and the microbial gelling agent are added, stirred and reacted to form a first gel coating layer; the first gel coating layer coated with the first bacterial species is then placed in a nutrient suspension, and the second bacterial species and the microbial gelling agent are added, stirred and reacted to form a second gel coating layer, and the above method is repeated to sequentially prepare a third gel coating layer coated with a third bacterial species and a fourth gel coating layer coated with a fourth bacterial species, and the intermediate layer coating the core layer is prepared;

[0026] S5. Outer layer preparation:

[0027] The inorganic porous carrier is dispersed to form a suspension, and the intermediate layer prepared in step S4 is added to cover the core layer, and the mixture is stirred evenly. Then, a flocculant is added, stirred to react, filtered, cooled and dried to obtain a substrate improver.

[0028] In the above preparation method, the plant seeds are first activated, which is beneficial to the subsequent germination and growth of the plant seeds; the bacterial strains are first cultured to the exponential growth phase, which is beneficial to the subsequent use of the bacterial strains; the activated plant seeds are coated with chitosan and a microbial gel agent. After coating, low-temperature freeze-drying is carried out, which is beneficial to controlling the moisture content in the space of the activated seeds and the coating, avoiding excessive moisture and causing seed rot. At the same time, through low-temperature freeze-drying, the surface hardness of the gel increases, which is beneficial to the subsequent coating of the middle layer of the bacterial strains.

[0029] The coating treatment of the bacterial strain layer is carried out on the surface of the activated seeds in the core layer, so that the bacterial strains with different functions are in different coating layers. When in use, the competition between different bacterial strains is avoided. And the bacterial strain coating layer located on the outer layer will decompose first, improving the sediment environment, which is beneficial to the survival of the bacterial strains located in the inner layer and the further improvement of the sediment environment after subsequent decomposition.

[0030] After the action of all the bacterial strains, the seeds located in the core layer are exposed, and the activated seeds come into contact with the improved sediment environment, which is beneficial to the growth and germination of the seeds, thus accelerating the construction and restoration of the submerged plant ecosystem.

[0031] The inorganic porous carrier is coated on the surface of the middle layer of the bacterial strains coated layer by layer. On the one hand, when the modifier is used, it can adsorb the suspended substances in the water body, improve the clarity of the water body, and further promote the penetration of sunlight through the water body, which is beneficial to the action of the bacterial strains. The adsorption of the suspended substances can increase the weight of the modifier, making it easier for the modifier to sink into the sediment; on the other hand, the coating of the inorganic porous carrier is beneficial to the transportation and retention of the modifier, and can also improve the survival rate of benthic animals.

[0032] Preferably, in the step S1, the plant regulator is one or a combination of gibberellin, urea, forchlorfenuron, triacontanol.

[0033] More preferably, in the step S1, the plant regulator is gibberellin.

[0034] Preferably, the microbial gel agent in the steps S3 and S4 is pullulan. During the addition of pullulan, the temperature is controlled at 28-35 °C.

[0035] By controlling the stirring reaction temperature of the microbial gel agent, on the one hand, the inactivation of the microorganisms or the activated seeds is avoided, and on the other hand, it is beneficial for the microbial gel agent to achieve the best flocculation effect.

[0036] Preferably, in the step S4, the nutrient suspension is one or a combination of starch suspension, soybean powder suspension, peptone suspension.

[0037] More preferably, the nutrient suspension is a mixture of starch suspension and soybean powder suspension, and the volume ratio is 1:1.

[0038] Preferably, the first bacterial strain is a mixed strain of photosynthetic bacteria and cyanobacteria, the second bacterial strain is yeast, the third bacterial strain is Bacillus, and the fourth bacterial strain is nitrifying bacteria.

[0039] The photosynthetic bacteria and cyanobacteria are coated on the outermost layer. When the modifier sinks into the anaerobic environment of the sediment, through the action of light, the photosynthetic bacteria can preliminarily decompose organic matter and absorb toxic and harmful gases, such as hydrogen sulfide, etc. In this process, the cyanobacteria produce oxygen under the action of light. The two jointly improve the anaerobic environment in the uppermost layer of the sediment, disintegrate the anaerobic environment, preliminarily improve the sediment environment, and are beneficial to the action of subsequent bacterial strains;

[0040] The yeast is coated on the second layer. Since yeast is an alkaline anaerobic bacterium, it can play a role in both aerobic and anaerobic environments. When the photosynthetic bacteria and cyanobacteria improve the anaerobic environment, considering that the anaerobic environment may not be completely disintegrated, yeast is used in this environment to further degrade organic matter, so that the substrate forming the anaerobic environment is further decomposed, thereby completely disintegrating the anaerobic environment and reducing the organic matter content in the sediment again.

[0041] The Bacillus is coated on the third layer. Bacillus is a strictly aerobic or facultatively anaerobic bacillus with a capsule, which can play a role in inhibiting bacteria and preventing various plant diseases, and also has biological activities such as phosphorus solubilization, potassium solubilization, and nitrogen fixation, which can improve the pH environment of the sediment and reduce harmful pathogens in the sediment environment, and is beneficial to the survival of subsequent bacterial strains.

[0042] The nitrifying bacteria are coated on the fourth layer. On the basis of the improvement of the sediment environment by the first three layers of microbial bacterial strains, the nitrifying bacteria can survive and grow. Since the nitrifying bacteria can convert nitrite and ammonia in the sediment into nitrate, while reducing the harmful substances in the sediment, it can also provide nitrogen fertilizer for the activated seeds, so that the activated seeds can grow more rapidly after germination, and thus restore the submerged plant ecosystem faster.

[0043] In summary, by distributing the above different bacterial strains in different coating layers, the mutual competition between different bacterial strains is avoided, and the action of the outer-layer bacterial strains can improve the living environment for the inner-layer bacterial strains. Thus, under the action of layer-by-layer improvement and mutual cooperation, a greater effect can be achieved with a relatively smaller dosage, accelerating the restoration of the substrate of the multi-pond wetland. In addition, as a coating material, the microbial gel can not only be decomposed by microbial bacterial strains, but also be non-toxic and harmless, and will not cause secondary pollution.

[0044] Preferably, in the step S5, before the inorganic porous carrier is dispersed, an acid washing operation is also performed.

[0045] The pickling operation is conducive to removing impurities in the inorganic porous carrier, making the pores smoother and the pore diameter larger, so as to adsorb more suspended substances, which is more conducive to the growth of seeds in the subsequent activated seed production process.

[0046] (III) Beneficial effects

[0047] The present invention provides a substrate modifier for a multi-pond wetland and a preparation method thereof. Compared with the prior art, the following beneficial effects are achieved:

[0048] 1. The substrate modifier for the multi-pond wetland of the present invention uses an inorganic porous carrier as the shell layer. When in use, it can adsorb suspended substances in the water before sinking into the bottom mud, which helps to clarify the water body. Moreover, the inorganic porous carrier increases its own weight due to the adsorption of suspended substances, which can accelerate the sinking into the bottom mud. After sinking into the bottom mud, the intermediate layers formed by different strains decompose the bottom mud layer by layer, degrade the organic matter in the bottom mud, improve the bottom quality of the bottom mud, make the bottom mud conducive to the growth of submerged plants. Through a series of reactions, the submerged plant seeds located in the core layer sink into the bottom mud and germinate and grow through the submerged plant seeds, thereby further improving the bottom mud environment and being conducive to the restoration of the submerged plant ecosystem;

[0049] 2. By distributing different strains in different coating layers, the mutual competition between different strains is avoided, and the action of the outer-layer strains can improve the living environment for the inner-layer strains. Thus, under the cooperative action, a greater effect can be achieved with a relatively smaller dosage, accelerating the restoration of the substrate of the multi-pond wetland. The microbial gel agent as the coating material can not only be decomposed by microbial strains, but also is non-toxic and harmless, and will not cause secondary pollution;

[0050] 3. The substrate of the multi-pond wetland improved by the modifier is not only conducive to the rapid restoration of submerged plants, but also can be used to purify the tail water of sewage treatment plants. Specific embodiments

[0051] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0052] In an embodiment of the present invention, by providing a substrate modifier for a multi-pond wetland and a preparation method thereof, the problems of large dosage of existing modifiers and poor improvement effect on the bottom mud environment are solved. After the substrate modifier for the multi-pond wetland prepared in the present invention is put into use, it can not only clarify the water body, reduce the suspended matter in the water body, but also improve the substrate of the multi-pond wetland, reduce the organic matter content in the bottom mud, and is beneficial to the restoration of the submerged plant ecosystem. After the submerged plants grow, the multi-pond wetland can be used for the advanced ecological purification of the tail water of the sewage treatment plant.

[0053] In order to better understand the above technical solution, the following will describe the above technical solution in detail in combination with specific embodiments.

[0054] The inorganic porous carrier is coarse diatomaceous earth, with a particle size D 50 = 30 - 150 um;

[0055] The strains are: photosynthetic bacteria, cyanobacteria, yeast, Bacillus, nitrifying bacteria; among them, Bacillus is Bacillus subtilis and Bacillus licheniformis, and the mass ratio of Bacillus subtilis to Bacillus licheniformis is 1:1;

[0056] The plant seeds are Potamogeton crispus seeds.

[0057] Example 1:

[0058] A substrate modifier for a multi-pond wetland is prepared with an inorganic porous carrier as the shell layer, strains as the intermediate layer, and plant seeds as the core layer. The specific preparation method is as follows:

[0059] S1. Seed activation:

[0060] Soak 2 parts by mass of Potamogeton crispus seeds in water for 1 h, then add 0.1 part by mass of gibberellin, soak for 20 min. During the soaking process, stir slowly and fish out and dry.

[0061] S2. Strain cultivation:

[0062] S21. Inoculate photosynthetic bacteria onto a photosynthetic bacteria agar medium and culture at room temperature for 36 h. After culturing until adhering to the wall, collect into a culture bottle;

[0063] S22. Inoculate cyanobacteria onto a cyanobacteria medium and culture under light conditions at 23 °C for 48 h. Cultivate until the logarithmic growth phase and collect into a culture bottle;

[0064] S23. Inoculate yeast onto an agar medium and culture at room temperature for 32 h. After culturing until adhering to the wall, collect into a culture bottle;

[0065] S24. Inoculate Bacillus subtilis and Bacillus licheniformis onto two broth culture media respectively, and culture them at 30°C for 24 hours. After culturing until they adhere to the wall, collect them into collection bottles respectively, and then mix Bacillus subtilis and Bacillus licheniformis in a mass ratio of 1:1;

[0066] S25. Inoculate nitrifying bacteria onto a urea culture medium, and culture them at 20°C until they adhere to the wall, then collect them into a culture bottle;

[0067] S3. Nuclear layer preparation:

[0068] Place 5 Potamogeton crispus seeds treated in step S1 into 0.2 L of clear water, add 40 ml of chitosan acetate solution and 0.3 parts by mass of pullulan. First, let it stand still to make the bad seeds float, take out the bad seeds, and then stir and react to form a gel. Freeze-dry it at 2°C for later use;

[0069] S4. Preparation of the bacterial strain intermediate layer:

[0070] S41. Place the gel formed in step S3 into a mixture of 100 ml of a 1:1 starch suspension and soybean powder suspension, add 0.5 parts by mass of a 1:1 mixture of photosynthetic bacteria and cyanobacteria and 0.4 parts by mass of pullulan, stir and react to form a first gel coating layer;

[0071] S42. Then place the first gel coating layer into a mixture of 100 ml of a 1:1 starch suspension and soybean powder suspension, add 0.3 parts by mass of yeast and 0.34 parts by mass of pullulan, stir and react to form a second gel coating layer;

[0072] S43. Place the second gel coating layer into a mixture of 100 ml of a 1:1 starch suspension and soybean powder suspension, add 0.2 parts by mass of a 1:1 mixture of Bacillus subtilis and Bacillus licheniformis and 0.25 parts by mass of pullulan, stir and react to form a third gel coating layer;

[0073] S44. Place the third gel coating layer into a mixture of 100 ml of a 1:1 starch suspension and soybean powder suspension, add 0.2 parts by mass of nitrifying bacteria and 0.25 parts by mass of pullulan, stir and react to form a fourth gel coating layer, and the preparation of the intermediate layer coating the nuclear layer material is completed;

[0074] S5. Outer layer preparation:

[0075] After washing the crude diatomite with 0.5 mol / L dilute acid salt, 0.8 parts by mass of the crude diatomite is dispersed in 200 ml of clear water to form a suspension. The intermediate layer coating core layer material prepared in step S4 is added, stirred evenly, then 0.1 part by mass of polyferric sulfate flocculant is added, stirred and reacted, filtered by suction, cooled and dried to obtain a substrate conditioner.

[0076] Example 2:

[0077] In this example, the raw materials used are the same as those in Example 1, and the activation method of the seeds and the cultivation method of the strains are the same. The differences are as follows:

[0078] S3. Core layer preparation:

[0079] Place 5 Potamogeton crispus seeds that have undergone step S1 in 0.2 L of clear water, add 40 ml of chitosan acetate solution and 0.3 parts by mass of pullulan. First, let it stand still to make the bad seeds float, take out the bad seeds, and then stir and react to form a gel. Under the condition of 2 °C, freeze-dry at low temperature for standby;

[0080] S4. Strain intermediate layer preparation:

[0081] S41. Place the gel formed in step S3 in a mixture of 100 ml of a starch suspension and a soybean powder suspension with a volume ratio of 1:1, add 0.8 parts by mass of photosynthetic bacteria and cyanobacteria with a mass ratio of 1:1 and 0.6 parts by mass of pullulan, stir and react to form a first gel coating layer;

[0082] S42. Then place the first gel coating layer in a mixture of 100 ml of a starch suspension and a soybean powder suspension with a volume ratio of 1:1, add 0.52 parts by mass of yeast and 0.55 parts by mass of pullulan, stir and react to form a second gel coating layer;

[0083] S43. Place the second gel coating layer in a mixture of 100 ml of a starch suspension and a soybean powder suspension with a volume ratio of 1:1, add 0.35 parts by mass of Bacillus subtilis and Bacillus licheniformis with a mass ratio of 1:1 and 0.3 parts by mass of pullulan, stir and react to form a third gel coating layer;

[0084] S44. Place the third gel coating layer in a mixture of 100 ml of a starch suspension and a soybean powder suspension with a volume ratio of 1:1, add 0.3 parts by mass of nitrifying bacteria and 0.3 parts by mass of pullulan, stir and react to form a fourth gel coating layer, and the preparation of the intermediate layer coating core layer material is completed;

[0085] S5. After washing the crude diatomaceous earth with 0.5 mol / L dilute acid salt, disperse 1.0 part by mass of the crude diatomaceous earth in 200 ml of clear water to form a suspension. Add the intermediate layer-coated core layer material prepared in step S4, stir evenly, then add 0.15 part by mass of polyferric sulfate flocculant, stir and react, filter by suction, cool and dry to obtain the substrate conditioner.

[0086] Example 3

[0087] In this example, the raw materials used are the same as those in Example 1, and the activation method of the seeds and the cultivation method of the strains are the same. The differences are as follows:

[0088] S3. Core layer preparation:

[0089] Place 5 Potamogeton crispus seeds that have undergone step S1 in 0.2 L of clear water, add 40 ml of chitosan acetate solution and 0.3 part by mass of pullulan. First, let it stand still to make the bad seeds float, take out the bad seeds, and then stir and react to form a gel. Under the condition of 2 °C, freeze-dry at low temperature for standby;

[0090] S4. Intermediate layer preparation of strains:

[0091] S41. Place the gel formed in step S3 in a mixture of 120 ml of a 1:1 starch suspension and soybean powder suspension, add 1.2 parts by mass of photosynthetic bacteria and cyanobacteria with a mass ratio of 1:1 and 0.9 part by mass of pullulan, stir and react to form the first gel coating layer;

[0092] S42. Then place the first gel coating layer in a mixture of 50 ml of a 1:1 starch suspension and soybean powder suspension, add 0.4 part by mass of yeast and 0.3 part by mass of pullulan, stir and react to form the second gel coating layer;

[0093] S43. Place the second gel coating layer in a mixture of 50 ml of a 1:1 starch suspension and soybean powder suspension, add 0.3 part by mass of Bacillus subtilis and Bacillus licheniformis with a mass ratio of 1:1 and 0.25 part by mass of pullulan, stir and react to form the third gel coating layer;

[0094] S44. Place the third gel coating layer in a mixture of 50 ml of a 1:1 starch suspension and soybean powder suspension, add 0.2 part by mass of nitrifying bacteria and 0.25 part by mass of pullulan, stir and react to form the fourth gel coating layer;

[0095] S5. Outer layer preparation:

[0096] After cleaning the crude diatomite with 0.5 mol / L dilute acid salt, 1.0 part by mass of the crude diatomite is dispersed in 200 ml of clear water to form a suspension. The intermediate layer-coated core layer material prepared in step S4 is added, stirred evenly, and then 0.15 part by mass of polyferric sulfate flocculant is added, stirred and reacted, filtered by suction, cooled and dried to obtain a bottom quality improver.

[0097] Comparative Example 1

[0098] The difference from Example 1 is that the seeds are not activated.

[0099] Comparative Example 2

[0100] The difference from Example 1 is that photosynthetic bacteria, cyanobacteria, yeasts, bacilli, and nitrifying bacteria are directly mixed with the activated seeds without separate coating.

[0101] Comparative Example 3

[0102] The difference from Example 1 is that after the seeds are activated, photosynthetic bacteria, cyanobacteria, yeasts, bacilli, nitrifying bacteria, and diatomite are mixed evenly and then the seeds are coated.

[0103] Experimental Data and Analysis

[0104] The bottom quality improvers prepared in Examples 1-3 and Comparative Examples 1-3 are used to improve the bottom mud of a former fish pond but currently unstocked fish pond, and the following tests are carried out;

[0105] Seven culture glass tanks with length×width×height = 100×60×80 cm are selected and numbered 1-7. In each glass tank, in-situ bottom mud of 10 cm third interface layer soil, second interface layer bottom mud, and first interface layer material is laid in sequence from bottom to top, and then 35 cm of raw water is added. In glass tanks 1-6, one of the improvers prepared in Examples 1-3 and Comparative Examples 1-3 is added correspondingly, and the addition amount is 30 g / kg. The 7th glass tank without adding the bottom quality improver is used as the control group and placed in an environment simulating sunlight. The results are shown in the following table:

[0106] Table 1 - Improvement data table of fish pond bottom quality by Examples 1-3, Comparative Examples 1-3 and the control group

[0107]

[0108] It can be seen from the above data that the improvers prepared in Examples 1-3 of the present invention can not only clarify the water body, reduce the suspended matter in the water body, but also improve the bottom quality of the multi-pond wetland, reduce the organic matter content in the bottom mud, and is beneficial to the restoration of the submerged plant ecosystem. After the submerged plant Potamogeton crispus grows, the multi-pond wetland can be used for the advanced ecological purification of the tail water of the sewage treatment plant.

[0109] By comparing the data in Examples 1-3 with the data in Comparative Example 1, it can be seen that activating the seeds first can effectively improve the germination rate of the seeds in the sediment, so that the germinated Potamogeton crispus can further improve the sediment environment.

[0110] By comparing the data in Examples 1-3 with the data in Comparative Example 2, it can be seen that the method of coating different strains layer by layer can improve the degradation amount of organic matter in the sediment by the strains more than directly mixing the strains, and can further increase the germination rate of the seeds.

[0111] By comparing the data in Examples 1-3 with the data in Comparative Example 3, it can be seen that using diatomite as the outermost layer to coat different strains and seeds therein can not only greatly improve the clarity of the water body, but also increase the decomposition amount of nitrogen and phosphorus in the sediment.

[0112] In summary, compared with the prior art, the following beneficial effects are achieved:

[0113] 1. The bottom sediment modifier for multi-pond wetlands of the present invention uses an inorganic porous carrier as the shell layer. When in use, it can adsorb the suspended substances in the water body before sinking into the sediment, which helps to clarify the water body. And due to the increase in its own weight by adsorbing the suspended substances, the inorganic porous carrier can sink into the sediment faster. After sinking into the sediment, the intermediate layer formed by different strains acts on the sediment layer by layer, degrading the organic matter in the sediment, improving the bottom quality of the sediment, making the sediment conducive to the growth of submerged plants. After a series of reactions, the submerged plant seeds located in the core layer sink into the sediment, and through the germination and growth of the submerged plant seeds, the sediment environment is further improved, which is beneficial to the restoration of the submerged plant ecosystem;

[0114] 2. By distributing different strains in different coating layers, the mutual competition between different strains is avoided, and the action of the outer layer strains can improve the living environment for the inner layer strains. Thus, under the combined action, a greater effect can be achieved with a relatively smaller dosage, accelerating the restoration of the bottom sediment of multi-pond wetlands. The microbial gel agent as the coating material can not only be decomposed by microbial strains, but also is non-toxic and harmless, and will not cause secondary pollution;

[0115] 3. The bottom sediment of the multi-pond wetland improved by the modifier is not only conducive to the rapid restoration of submerged plants, but also can be used to purify the tail water of sewage treatment plants.

[0116] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0117] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a substrate conditioner for a multi-pond wetland, characterized in that, The substrate conditioner is prepared with an inorganic porous carrier as the shell layer, strains as the intermediate layer, and plant seeds as the core layer. The intermediate layer is a coating structure in which different strains are distributed in different coating layers; The preparation method includes the following steps: S1. Seed activation: Soak the plant seeds for 1 - 3 h, then add a plant regulator and soak for 20 - 30 min, fish out and air dry; S2. Strain culture: Place different strains on different solid media and culture for 24 - 48 h. After culturing until they adhere to the wall, collect them separately; S3. Core layer preparation: Place the plant seeds that have gone through step S1 in water, add a chitosan solution and a microbial gelling agent, let it stand still first, then stir and react to form a gel, and freeze - dry at low temperature for standby; S4. Intermediate layer of strains preparation: Place the gel formed in step S3 in a nutrient suspension, add the first strain and a microbial gelling agent, stir and react to form a first gel coating layer; then place the first gel coating layer coated with the first strain in the nutrient suspension, add the second strain and the microbial gelling agent, stir and react to form a second gel coating layer. Repeat the above method to sequentially prepare a third gel coating layer coated with the third strain and a fourth gel coating layer coated with the fourth strain. The preparation of the intermediate layer coating the core layer is completed; Among them, the nutrient suspension is one or a combination of starch suspension, soybean powder suspension, peptone suspension; the first strain is a mixed strain of photosynthetic bacteria and cyanobacteria, the second strain is yeast, the third strain is Bacillus, and the fourth strain is nitrifying bacteria; S5. Outer layer preparation: Disperse the inorganic porous carrier to form a suspension, add the intermediate layer coating the core layer prepared in step S4, stir evenly, then add a flocculant, stir and react, filter by suction, and cool and dry to obtain the substrate conditioner.

2. The preparation method of a multi-pond wetland substrate conditioner according to claim 1, characterized in that, The substrate conditioner includes by weight: 10 - 30 parts of inorganic porous carrier, 5 - 10 parts of strains, and 2 - 5 parts of plant seeds.

3. The preparation method of a multi-pond wetland substrate conditioner as claimed in claim 1, wherein, The inorganic porous carrier is one or a combination of diatomite, zeolite, activated carbon, porous alumina, porous ceramics.

4. The preparation method of a substrate conditioner for a multi-pond wetland according to claim 1, characterized in that, The plant seeds are one or a combination of Potamogeton crispus seeds, Vallisneria natans seeds, Hydrilla verticillata seeds, Ceratophyllum demersum seeds, Myriophyllum verticillatum seeds, Potamogeton distinctus seeds.

5. The preparation method of a sediment conditioner for a multi-pond wetland according to claim 1, characterized in that, In step S1, the plant regulator is one or a combination of gibberellin, urea, forchlorfenuron, triacontanol.

6. The preparation method of a multi-pond wetland substrate conditioner as described in claim 1, characterized in that, The microbial gelling agents in steps S3 and S4 are both pullulan. During the addition of pullulan, control the temperature at 28 - 35 °C.

7. The preparation method of a substrate conditioner for a multi-pond wetland according to claim 1, characterized in that In step S5, before the inorganic porous carrier is dispersed, an acid - washing operation is also carried out.

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