Growth-promoting submerged plant planting unit prepared from recycled paper pulp and method

Abstract

The invention discloses a growth-promoting submerged plant planting unit prepared from recycled paper pulp and a method, the growth-promoting submerged plant planting unit comprises a planting unit shell base and a planting unit shell cover body, and the planting unit shell base and the planting unit shell cover body are both made of a mixture formed by mixing recycled paper pulp fibers, a water-soluble polyvinyl alcohol solution, starch and bentonite. The bottom of the planting unit shell base is covered with calcium peroxide, the upper portion of the planting unit shell base is filled with planting matrix materials, gaps are filled with plant growth-promoting bacteria, reserved plant holes are formed in the top of the planting unit shell cover body, and submerged plants are planted in the planting matrix materials through the reserved plant holes. The substrate is environment-friendly in material, high in degradation rate and free of environmental hazard after degradation, the polluted bottom mud environment can be improved through configuration of the planting unit substrate, the adaptability and stress resistance rate of planting of submerged plants in polluted water are effectively improved, the survival rate of planting of the submerged plants is increased, and the number of times of reseeding in the later period is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of water ecological restoration, and more specifically, to a submerged plant growth promoting unit and method prepared by using recycled paper pulp. Background Art

[0002] As an important part of the urban water system, the pollution of shallow lakes directly affects the quality of life of urban residents and the sustainable development of the city. The water quality of many shallow lakes has deteriorated, the degree of eutrophication has increased, the biodiversity has decreased, and even the quality of life of surrounding residents has been affected. The main causes of pollution in urban shallow lakes include: the discharge of domestic sewage and industrial wastewater, agricultural non-point source pollution, insufficient ecological water replenishment, and the decline in the self-purification capacity of water bodies. In recent years, my country has invested heavily in the restoration of water ecology in urban shallow lakes, and the results are quite significant. In the field of water environment ecological restoration projects, it is crucial to restore submerged plants in shallow lakes. The restoration effect of submerged plants directly affects all aspects of the restoration project. However, in the actual construction process, cutting method and casting method are more commonly used methods for planting submerged plants. The cutting method is suitable for waters with shallow water depth and soft bottom, but it is often impossible to control the cutting depth, resulting in a low planting survival rate. The casting method is not affected much by the water depth and the hardness of the bottom. The soil bags of submerged plants are thrown into the water body and naturally settle to the surface of the sediment. As the plant roots grow and penetrate into the sediment, the survival rate is affected by the pollution of the bottom sediment. In some areas with serious bottom sediment pollution, the conventional planting soil matrix is ​​easily assimilated by the polluted bottom sediment, which poses a threat to the growth of plants.

[0003] At present, in order to improve the survival rate of submerged plants in the process of ecological restoration, multi-stage step-by-step construction is basically adopted in practical engineering applications. First, the micro-polluted water environment is improved and then the submerged plants are restored. For example, patent CN111170400A, the multi-stage step-by-step construction has the disadvantages of long cycle and large personnel cost investment. For the submerged plant planting method, planting beds and planting bags or planting cups for single plants are mostly used. For example, CN212260057U, CN108401730B, the polymer materials used in these planting devices have a degradation rate of 78% within 4 months under natural conditions, and microplastics are easily generated during the degradation process, which has potential environmental hazards. The effect of using modifiers to treat the water environment in the early stage of submerged plant restoration is greatly affected by the weather, and the dosage needs to be adjusted many times, the construction period is long, and the process is cumbersome. In current research, the materials of submerged plant planting devices are mostly materials that cannot be degraded or have a long degradation period. The degradation conditions of some device materials are harsh, and microplastics are easily generated during the degradation process, which poses a potential threat to the environment. At the same time, the conventional planting substrates used in these devices have a single function, which only provides good nutrition for the initial colonization of submerged plants and has no effect on the environment. Pulp fiber has good environmental friendliness and its degradation rate is better than that of polymer materials in natural environments. The degradation time of ordinary paper product materials in natural water bodies is more than 2 weeks. After modification, its permeability and degradation rate can be further improved. By using waste paper materials to extract pulp fibers, the resource utilization of waste can be effectively realized and the recycling rate of waste paper can be improved.

[0004] In summary, the current planting devices have shortcomings such as slow material degradation rate and single matrix function. There is an urgent need for a multifunctional planting device made of environmentally friendly materials. Summary of the invention

[0005] One object of the present invention is to provide a submerged plant planting unit and method prepared by using recycled pulp. In shallow lake water under slightly polluted conditions, the use of high-efficiency oxygenation and plant growth-promoting bacteria is combined to improve the bottom mud environment during the submerged plant planting process. The material is environmentally friendly, has a fast degradation rate, and has no environmental harm after degradation. The configuration of the planting unit matrix can improve the polluted bottom mud environment and thus effectively improve the adaptability and stress resistance of submerged plant planting in polluted water bodies, thereby improving the survival rate of submerged plant planting and reducing the number of subsequent replanting times.

[0006] In order to solve the above technical problems, the present invention provides a submerged plant growth promoting planting unit prepared by recycled pulp, comprising a planting unit shell base and a planting unit shell cover, both of which are hollow structures, the planting unit shell base is an integrated structure of a lower cone and an upper column, the planting unit shell cover is an integrated structure of an upper cone and a lower column, the planting unit shell base and the planting unit shell cover are both made of a mixture formed by mixing recycled pulp fibers, water-soluble polyvinyl alcohol solution, starch and bentonite, the lower part of the planting unit shell cover is placed in the upper part of the planting unit shell base, and the two have the same height and the central axes coincide, the bottom of the planting unit shell base is covered with calcium peroxide, the outer walls of the planting unit shell base and the planting unit shell cover are filled with plant growth promoting bacteria, the remaining space of the planting unit shell base and the planting unit shell cover is filled with planting matrix material, and reserved plant holes are provided on the top of the planting unit shell cover, and submerged plants are planted in the planting matrix material through the reserved plant holes.

[0007] Preferably, the planting matrix material is a mixture of treated medical stone and humus, the mass ratio of medical stone to humus is 1~2:10; the mass fraction of water-soluble polyvinyl alcohol solution is 5~15%, the amount of polyvinyl alcohol solution added to the recycled pulp modified fiber is 0.5~1ml / g; the mass ratio of recycled pulp modified fiber, bentonite, and starch is 1~3:0.5~1.5:0.5~1.5; the mass ratio of calcium peroxide, planting matrix, and plant growth-promoting agent is 1:8~15:1.

[0008] Preferably, the inner diameter of the implantation unit shell base is 10~20cm, the upper column height of the implantation unit shell base is 5~15cm, the lower vertebral height of the implantation unit shell base is 3~8cm, the vertebral height of the implantation unit shell cover is 1~5cm, the reserved hole diameter of the implantation unit shell cover is 1~3cm, and the width of the gap between the outer wall of the implantation unit shell cover and the inner wall of the implantation unit shell base is 1~3cm.

[0009] The present invention also provides a method for preparing a submerged plant growth promoting unit using recycled paper pulp, comprising the following steps: Step 1: After the recycled waste paper is processed, it is soaked in water for a set time to soften, and pulp fibers are formed through mechanical treatment in the process; the pulp fibers are filtered, and then soaked in an alkaline solution for alkaline washing; the pulp fibers after alkaline washing are washed with water until neutral, and then soaked in a hydrogen peroxide solution; filtered to obtain recycled pulp modified fibers; Step 2: Mix the recycled pulp modified fiber obtained above with a water-soluble polyvinyl alcohol solution, add starch and bentonite during the mixing process to form a uniform mixture, and then spread the mixture on the mold surface corresponding to the planting unit shell base and the planting unit shell cover, and obtain the planting unit shell base and the planting unit shell cover after demoulding; Step 3: soaking the medical stone material in the alkali washing waste liquid filtered out in step 1 for a set time, then taking out the soaked medical stone material, washing it to neutrality, and then mixing it with humus soil to obtain a planting unit planting matrix material; Step 4: Pre-treat the submerged plants to be planted; Step 5: Cover the bottom of the planting unit shell base obtained in step 2 with a set thickness of calcium peroxide, and then fill the bottom cone structure with the planting matrix material obtained in step 3; place the planting unit shell cover obtained in step 2 into the planting unit shell base, fill the inner space with the planting matrix material obtained in step 3 through the reserved plant holes on the top of the planting unit shell cover, and fill the gap between the outer periphery of the planting unit shell cover and the planting unit shell base with a plant growth-promoting agent to obtain a planting unit base; Step 6: insert the submerged plants processed in step 4 into the filled planting matrix material through the reserved plant holes on the top of the planting unit housing cover to a set depth, thereby obtaining a planting unit; Step 7: Throw the obtained planting unit into the water body and let it settle on the surface of the bottom mud to achieve the colonization of submerged plants.

[0010] Preferably, in step one, the recycled waste paper is waste corrugated paper generated by the express packaging industry or waste paper or waste pulp fiber products generated in the office field; the alkaline washing is carried out in a 10% by mass NaOH solution for 1 to 3 hours; the H2O2 solution has a mass fraction of 3% and is soaked for 0.5 to 2 hours.

[0011] Preferably, in step 2, the mass fraction of the water-soluble polyvinyl alcohol solution is 5-15%, the amount of polyvinyl alcohol solution added to the recovered pulp modified fiber is 0.5-1 ml / g; the mass ratio of the recovered pulp modified fiber, bentonite and starch is 1-3:0.5-1.5:0.5-1.5.

[0012] Preferably, in step three, the alkali washing waste liquid is soaked in the medical stone material for 1.5 to 3 hours; and the mass ratio of medical stone to humus soil is 1 to 2:10.

[0013] Preferably, in step 4, pretreatment of submerged plants includes: removing leaves of plants that are rotten or in poor growth condition and screening out withered and rotten plants, and dividing the plants into clumps of 5 to 15 plants per clump for later use; the submerged plants are Vallisneria, Potamogeton fasciatus, Hydrilla verticillata, and Potamogeton crispus.

[0014] Preferably, in step five, the plant growth-promoting bacteria include Bacillus, nitrogen-fixing bacteria, and Pseudomonas, all of which are powders, with a mass ratio of 1.5~2.5:0.5~1.5:0.5~1.5, and a cell density of the bacteria is 3~4.5 billion / g; the mass ratio of calcium peroxide, planting matrix material, and plant growth-promoting bacteria is 1:8~15:1.

[0015] Preferably, in step six, the planting depth is 3~5cm; the inner diameter of the planting unit shell base is 10~20cm, the upper column height of the planting unit shell base is 5~15cm, the lower vertebral height of the planting unit shell base is 3~8cm, the vertebral height of the planting unit shell cover is 1~5cm, the reserved hole diameter of the planting unit shell cover is 1~3cm, and the width of the gap between the outer wall of the planting unit shell cover and the inner wall of the planting unit shell base is 1~3cm.

[0016] The present invention has at least the following beneficial effects: 1. The present invention utilizes a high-efficiency oxygen-enhancing submerged plant planting unit prepared by modified fiber extracted from waste paper. On the premise of realizing waste resource utilization, it is applied to the ecological restoration of submerged plants in polluted water bodies of shallow lakes. After alkali washing + hydrogen peroxide modification molding, it can have good water permeability and degradation performance, which is beneficial to the contact between plant growth-promoting bacteria and bottom-improving agents and the external environment. There is no secondary pollution hazard after microbial degradation. It is green and friendly, easy to assemble, and the rapid degradation of materials is beneficial to the rapid colonization of submerged plants in the bottom mud, further improving the bottom mud improvement effect.

[0017] 2. The matrix configuration of the high-efficiency oxygen-enhancing submerged plant planting unit of the present invention, while improving the anaerobic state of the bottom mud and establishing an aerobic microenvironment of the bottom mud, effectively avoids the assimilation pollution of the polluted bottom mud to the planting matrix in the planting unit in the early stage of plant establishment and growth, effectively realizes the adaptability of the submerged plant in the early stage of establishment and growth, improves the survival rate of submerged plant planting, and reduces the number of later maintenance and replanting.

[0018] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a large-scale drawing of the high-efficiency oxygen-enhancing and growth-promoting submerged plant planting unit of the present invention; Figure 2 This is a schematic diagram of a highly efficient oxygen-enhancing growth-promoting submerged plant planting unit of the present invention; Figure 3 This is a base configuration diagram of the high-efficiency oxygen-enhancing and growth-promoting submerged plant planting unit of the present invention; Figure 4 This is a comparison diagram of the total phosphorus change curve of the overlying water quality of the present invention; Figure 5 This is a comparison diagram of the ammonia nitrogen change curve of the overlying water quality of the present invention; Figure 6 This is a comparison diagram of the changes in the morphology of phosphorus in the sediment of the present invention; Figure 7 This is a comparison chart of the number of new leaves per plant of Vallisneria ovalis of the present invention; Figure 8 This is a comparison chart of the lengths of individual Vallisneria plants of the present invention.

[0020] Description of reference numerals: 1-planting unit shell base, 2-planting unit shell cover, 3-calcium peroxide, 4-planting matrix material, 5-plant growth-promoting bacteria agent, 11-submerged plant, 12-planting unit base. DETAILED DESCRIPTION

[0021] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0022] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] During the restoration of submerged vegetation in polluted water bodies in urban shallow lakes, the nitrogen and phosphorus content of the polluted sediments exceeded the standard, which is not conducive to the growth of submerged plants. Without pre-treatment conditions for improving the bottom soil, the effect of planting submerged plants is not good. The anaerobic environment at the bottom of the polluted water body can easily cause the submerged plants to rot, further deteriorating the water environment. Conventional matrix planting bags can only provide a certain shelter for the early growth of submerged plants. Under long-term conditions, the assimilation of the matrix with the polluted sediment will also affect the growth effect of submerged plants. In addition, existing planting bags are mostly made of high-molecular polymer materials such as polyester fiber non-woven fabrics and polyethylene net bags. Not only do they have a long degradation cycle, but they are also prone to produce microplastics during the degradation process, which are potentially harmful to the environment.

[0024] To this end, the present invention uses a rapidly degradable green unit shell material made of modified pulp fiber extracted from waste corrugated paper, and compounded with calcium peroxide, medical stone, humus matrix and plant growth-promoting bacteria to prepare a submerged plant planting unit. The new submerged plant planting unit can effectively solve the pollution assimilation of polluted sediment to the matrix in the planting unit, and simultaneously achieve the improvement of sediment during the plant planting process. Calcium peroxide is used to improve the anaerobic state of the polluted sediment into an aerobic microenvironment, thereby improving the stress resistance and survival rate of submerged plants during the planting process and reducing the number of submerged plant replanting times. Compared with the traditional process of first improving sediment and then restoring submerged plants, the present invention integrates the sediment improvement effect into the submerged plant planting process, which simplifies the process of submerged plant restoration to a certain extent.

[0025] Considering the practical application of existing water ecological restoration technology, the present invention summarizes a submerged plant planting unit and a construction method thereof that uses recycled pulp to increase oxygen and promote growth. The planting unit provided by the present invention has a submerged plant planting unit that can be quickly degraded without secondary pollution after degradation and has a certain effect of improving the bottom quality. Its purpose is to improve the survival rate of planting in the project and improve the bottom mud environment of the slightly polluted water body.

[0026] like Figures 1 to 3 As shown, the present invention provides a submerged plant growth promoting planting unit prepared by using recycled pulp, including a planting unit shell base 1 and a planting unit shell cover 2, both of which are hollow structures, the planting unit shell base is an integrated structure of a lower cone and an upper column, the planting unit shell cover is an integrated structure of an upper cone and a lower column, the planting unit shell base and the planting unit shell cover are both made of a mixture formed by mixing recycled pulp fibers, water-soluble polyvinyl alcohol solution, starch and bentonite, the lower part of the planting unit shell cover is placed in the upper part of the planting unit shell base, and the two have the same height and the central axes coincide, the bottom of the planting unit shell base is covered with calcium peroxide 3, the outer wall of the planting unit shell base and the planting unit shell cover is filled with a plant growth promoting bacterium 5, the remaining space of the planting unit shell base and the planting unit shell cover is filled with a planting matrix material 4, and a reserved plant hole is provided on the top of the planting unit shell cover, forming a planting unit base 12 as a whole, and the submerged plant 11 is planted in the planting matrix material through the reserved plant hole. The planting matrix material is a mixture of processed medical stone and humus soil.

[0027] The present invention also provides a method for preparing a submerged plant growth-promoting planting unit using recycled pulp, which is achieved by the following steps: Step 1: Remove the adhesive and other debris on the surface of the recycled waste paper, cut it into small pieces, and soak the corrugated paper pieces in water for 0.5-2 hours to soften them, and break up the pulp fibers by continuous stirring and kneading; soak the filtered pulp fibers in a 10% by mass NaOH solution for 1-3 hours, take out the alkali-washed pulp fibers, wash them with water until they are neutral, and then soak them in a 3% by mass H2O2 solution for 0.5-2 hours, filter the solution and take it out to obtain the recycled pulp modified fiber; the source of waste paper can be waste corrugated paper generated by the express packaging industry, waste paper generated in the office field, domestic waste paper and other waste pulp fiber products.

[0028] Step 2: Mix the recycled pulp modified fiber and the water-soluble polyvinyl alcohol solution evenly, add starch and bentonite during the mixing process to form a uniform mixture, spread the mixture on the surface of the mold, put it into 60~80℃ for drying and hardening and demolding after extrusion molding, and check that there is no obvious breakage after demolding to obtain the base and cover of the recycled pulp modified fiber planting unit; the mass fraction of the water-soluble polyvinyl alcohol solution is 5~15%, and the amount of polyvinyl alcohol solution added to the recycled pulp modified fiber is 0.5~1ml / g. The mass ratio of recycled pulp modified fiber, bentonite, and starch is 1~3:0.5~1.5:0.5~1.5. The use of bentonite and starch can improve the strength of the recycled pulp modified fiber planting unit material after hardening and molding, and accelerate the expansion and dispersion of the planting unit shell after being put into the water body. Starch can be used as a carbon source for microbial growth, which is conducive to the attachment and growth of microorganisms and accelerates the degradation of the shell.

[0029] Step 3: Soak the medical stone material in the alkaline washing waste liquid filtered out in step 1 for 1.5 to 3 hours to clean the internal pores of the medical stone and improve the adsorption performance of the medical stone. After soaking, wash it with pure water until it is neutral and then mix it evenly with humus to obtain the planting unit planting matrix material; the mass ratio of medical stone to humus is 1 to 2:10.

[0030] Step 4: Pre-treat the submerged plants to be planted, remove the leaves that are rotten or in poor growth condition, and screen out the withered and rotten plants, and divide them into clumps of 5 to 15 plants per clump for later use; the submerged plants include Vallisneria, Potamogeton, Hydrilla, and Water Chestnut.

[0031] Step 5: Cover the bottom of the base of the recycled pulp modified fiber planting unit with a layer of calcium peroxide, fill the bottom cone structure with the planting unit planting matrix material, put the recycled pulp modified fiber planting unit cover into the base, fill the base with planting matrix material through the reserved plant holes in the cover, and fill the plant growth-promoting bacteria in the gap around the cover and the base to obtain the recycled pulp modified fiber planting unit base. Calcium peroxide uses food grade calcium peroxide with an effective content of 99%. The mass ratio of calcium peroxide, planting matrix, and plant growth-promoting bacteria is 1:8~15:1. The plant growth-promoting bacteria are commercially available bacteria, the types are Bacillus, nitrogen-fixing bacteria, and Pseudomonas, with a mass ratio of 1.5~2.5:0.5~1.5:0.5~1.5, all of which are powders, and the cell density of the bacteria is about 300~4500 million / g.

[0032] Step 6: Use a pointed clamp to insert the roots of submerged plants through the reserved plant holes in the cover to a depth of 3 to 5 cm into the planting matrix material, and then throw the recycled pulp modified fiber planting unit into the water body and let it settle on the bottom mud surface to achieve the colonization of submerged plants. The planting unit size is 10 to 20 cm in inner diameter, 5 to 15 cm in cylinder height, 3 to 8 cm in base vertebral height, 1 to 5 cm in cover vertebral height, 1 to 3 cm in reserved hole diameter, and 1 to 3 cm in width between the outer wall of the cover and the inner wall of the base.

[0033] The present invention not only provides a submerged plant planting unit that is highly efficient in oxygenation and growth promotion and is prepared using recycled pulp, but also provides a construction method for on-site planting. The planting unit that uses calcium peroxide high-efficiency substrate improvement agent, adsorbent mineral matrix material medical stone and humus as the planting matrix and a plant growth-promoting bacterial agent has multiple effects of sediment improvement and plant growth promotion. The planting unit material is environmentally friendly, degrades quickly, and degrades without secondary pollution. The survival rate of submerged plant planting can be improved by sediment improvement in urban shallow lakes with a water depth of ≤1.5m and a transparency of ≤0.5m under micro-pollution conditions, thereby reducing the number of replanting times.

[0034] In order to better understand the essence of the present invention, the technical content of the present invention is described below with a specific embodiment, in which the efficiency and survival rate of submerged plant planting are improved by configuring the planting unit in the range of water depth ≤1.5m and water transparency ≤0.5m in urban shallow lakes. However, the content of the present invention is not limited thereto.

[0035] Example 1: A highly efficient oxygen-enhancing and growth-promoting submerged plant planting unit prepared using recycled pulp is prepared by the following method: (1) Place the surface soil in a wide-mouth plastic barrel, add organic materials such as hay, fallen leaves, and straw to the soil and mix them evenly to obtain organic soil. The mass ratio of surface soil to organic materials is 1:1. Spray a small amount of brown sugar yeast solution on the mixed organic soil and compact it. Cover the compacted organic soil with a layer of surface soil 1 cm thick and ferment it at room temperature for 1 month to obtain humus soil. (2) Recycling waste corrugated paper from the express delivery industry, removing the adhesive substances on the surface, and then cutting it into small pieces. Soak the corrugated paper pieces in water for 1 hour to soften them, and break up the pulp fibers by continuous stirring and kneading. Soak the pulp fibers after water filtration in a 10% by mass NaOH solution for 1.5 hours, take out the pulp fibers after alkali washing, wash them with water until they are neutral, and then soak them in a 3% by mass H2O2 solution for 1 hour. Filter the solution and take it out to obtain the recycled pulp modified fiber. (3) 50 g of recycled pulp modified fiber, 25 g of bentonite, and 25 g of starch were mixed evenly, and then 25 ml of 5% water-soluble polyvinyl alcohol solution was added and stirred into a paste to obtain a wet material of recycled pulp modified fiber shell; (4) The wet material of the recycled pulp modified fiber shell is evenly spread on the mold, extruded into a conical structure with a diameter of 15 cm and a height of 20 cm, and placed together with the mold for drying at 80°C for 2 hours to solidify. After drying, the mold is removed, and after inspection without obvious damage, the base and cover of the recycled pulp modified fiber shell of the planting unit are obtained; (5) Spread a layer of 5g of powdered calcium peroxide at the bottom of the base of the recycled pulp modified fiber shell of the planting unit, fill the bottom vertebra with a portion of the planting matrix made by mixing 5g of medical stone (100 mesh size) and 45g of humus soil, then put it into the cover body with plant holes reserved and fill the remaining planting matrix inside the cover body, and then fill 5g of plant growth-promoting bacteria in the gap between the base of the recycled pulp modified fiber shell of the planting unit and the cover body to obtain the planting unit base; (6) Use tools to insert the roots of the submerged plant seedlings into the planting matrix at the base of the planting unit to a depth of about 4 cm, ensuring that the submerged plants are fixed in the matrix and cannot fall off easily, thus obtaining a complete planting unit.

[0036] Polluted lake water and sediment were collected from a certain area of ​​Jinyin Lake in Wuhan. The lake water body with a water depth of 50 cm and a black and smelly sediment thickness of 20 cm was simulated under indoor conditions. The prepared planting units were put into the simulated water body, and the changes in the degradation rate of planting bags made of different materials within a certain period of time were observed. At the same time, the changes in nitrogen and phosphorus in the sediment and lake water were monitored.

[0037] like Figure 4 and Figure 5 as well as Figure 6Shown are the curves of overlying water quality (total phosphorus, ammonia nitrogen content) and bottom mud phosphorus form content of submerged plant pulp planting units compared with planting bags of different materials under conventional substrates.

[0038] Figure 4 and Figure 5 It is shown that planting through planting units can significantly reduce the impact of suspended sediment on water quality caused by conventional cutting methods. The calcium peroxide at the bottom of the planting unit can effectively improve the anaerobic conditions of the sediment and, to a certain extent, promote the purification of nitrogen and phosphorus in the water during the growth of submerged plants. Figure 6 The results show the changes in the content of organic phosphorus, apatite phosphorus and non-apatite phosphorus forms in the sediment. The calcium peroxide at the bottom of the planting unit increases the redox potential of the anaerobic sediment, promotes the formation of exchangeable phosphorus (organic phosphorus and non-apatite phosphorus) in the sediment. The exchangeable phosphorus can be used by submerged plants and microorganisms to achieve the effect of phosphorus removal.

[0039] Embodiment 2: The application of the high-efficiency oxygen-enhancing growth-promoting submerged plant planting unit prepared by recycled pulp in the construction of submerged plant planting in lakes comprises the following steps: 1) The present invention was implemented in a restoration area of ​​Jinyin Lake in Wuhan City, Hubei Province. First, the water level was lowered to about 1m. According to the needs, 10 Vallisneria seedlings were placed in each planting bag for throwing and planting, ensuring a planting density of 50 plants / m 2 ; At the same time, experiments were conducted on non-woven planting bags with pure humus soil and PVC net planting bags.

[0040] 2) After the new paper pulp planting bags and the comparison planting bags were put into the water body, they were regularly monitored and maintained. The survival of submerged plants in the experimental area was monitored on the 10th, 20th and 30th days, and then monitored once a month. Rotten floating plants were salvaged and cleaned according to the maintenance and monitoring of the experimental area. The growth status of the plants was recorded on the 5th, 10th, 20th and 30th days.

[0041] Table 1 below and Figure 7 and Figure 8 As shown, the survival and growth status of the submerged plant Vallisneria ovalis during the planting process of a non-woven planting bag of pure humus soil, a PVC net bag planting bag and the planting unit of the present invention are compared.

[0042] Table 1 Survival of Vallisneria It can be seen from the above charts that planting submerged plants through planting units can significantly improve the stress resistance of submerged plants in polluted sediments. The number of new leaves and plant length of the submerged plant Vallisneria are better than those planted in conventional planting bags and conventional cuttings, and it has a certain effect of promoting plant growth.

[0043] The shell of the planting unit can achieve a degradation rate of 50% in lake water within 3 days, and a degradation rate of 79.5% within 7 days, which is significantly faster than the degradation rate of high molecular polymer materials. The rapid degradation of the shell material is conducive to the colonization of submerged plants in the bottom mud, further realizing the purification of polluted bottom mud.

[0044] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation mode, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, other modifications can be easily implemented, so without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A submerged plant growth promoting unit prepared by using recycled paper pulp, characterized in that: It includes a planting unit shell base and a planting unit shell cover, both of which are hollow structures. The planting unit shell base is an integrated structure of a lower cone and an upper column, and the planting unit shell cover is an integrated structure of an upper cone and a lower column. The planting unit shell base and the planting unit shell cover are both made of a mixture formed by mixing recycled pulp fiber, water-soluble polyvinyl alcohol solution, starch and bentonite. The lower part of the planting unit shell cover is placed in the upper part of the planting unit shell base, and the two have the same height and the central axes coincide. The bottom of the planting unit shell base is covered with calcium peroxide, and plant growth-promoting bacteria are filled between the outer walls of the planting unit shell base and the planting unit shell cover. The remaining space of the planting unit shell base and the planting unit shell cover is filled with planting matrix material. A reserved plant hole is provided on the top of the planting unit shell cover, and submerged plants are planted in the planting matrix material through the reserved plant hole.

2. The submerged plant growth promoting unit prepared by using recycled paper pulp according to claim 1, characterized in that: The planting matrix material is a mixture of treated medical stone and humus, the mass ratio of medical stone to humus is 1-2:10; the mass fraction of water-soluble polyvinyl alcohol solution is 5-15%, the amount of polyvinyl alcohol solution added to the recycled pulp modified fiber is 0.5-1 ml / g; the mass ratio of recycled pulp modified fiber, bentonite and starch is 1-3:0.5-1.5:0.5-1.5; the mass ratio of calcium peroxide, planting matrix and plant growth-promoting bacteria is 1:8-15:

1.

3. The submerged plant growth promoting unit prepared by using recycled paper pulp according to claim 1, characterized in that: The inner diameter of the implant unit shell base is 10~20cm, the upper column height of the implant unit shell base is 5~15cm, the lower vertebral height of the implant unit shell base is 3~8cm, the vertebral height of the implant unit shell cover is 1~5cm, the reserved hole diameter of the implant unit shell cover is 1~3cm, and the width of the gap between the outer wall of the implant unit shell cover and the inner wall of the implant unit shell base is 1~3cm.

4. A method for preparing a submerged plant growth promoting unit using recycled paper pulp, characterized in that: The steps include: Step 1: After the recycled waste paper is processed, it is soaked in water for a set time to soften, and pulp fibers are formed through mechanical treatment in the process; the pulp fibers are filtered and then soaked in an alkaline solution for alkaline washing; the pulp fibers after alkaline washing are washed with water until they are neutral, and then soaked in a hydrogen peroxide solution; Filtering to obtain recycled pulp modified fibers; Step 2: Mix the recycled pulp modified fiber obtained above with a water-soluble polyvinyl alcohol solution, add starch and bentonite during the mixing process to form a uniform mixture, and then spread the mixture on the mold surface corresponding to the planting unit shell base and the planting unit shell cover, and obtain the planting unit shell base and the planting unit shell cover after demoulding; Step 3: soaking the medical stone material in the alkali washing waste liquid filtered out in step 1 for a set time, then taking out the soaked medical stone material, washing it to neutrality, and then mixing it with humus soil to obtain a planting unit planting matrix material; Step 4: Pre-treat the submerged plants to be planted; Step 5: Cover the bottom of the planting unit shell base obtained in step 2 with a set thickness of calcium peroxide, and then fill the bottom cone structure with the planting matrix material obtained in step 3; place the planting unit shell cover obtained in step 2 into the planting unit shell base, fill the inner space with the planting matrix material obtained in step 3 through the reserved plant holes on the top of the planting unit shell cover, and fill the gap between the outer periphery of the planting unit shell cover and the planting unit shell base with a plant growth-promoting agent to obtain a planting unit base; Step 6: insert the submerged plants processed in step 4 into the filled planting matrix material through the reserved plant holes on the top of the planting unit housing cover to a set depth, thereby obtaining a planting unit; Step 7: Throw the obtained planting unit into the water body and let it settle on the surface of the bottom mud to achieve the colonization of submerged plants.

5. The method for preparing a submerged plant growth promoting unit using recycled paper pulp according to claim 4, characterized in that: In the step 1, the recycled waste paper is waste corrugated paper generated by the express packaging industry or waste paper or waste pulp fiber products generated in the office field; the alkaline washing is carried out in a 10% by mass NaOH solution for 1 to 3 hours; the H2O2 solution has a mass fraction of 3% and is soaked for 0.5 to 2 hours.

6. The method for preparing a submerged plant growth promoting unit using recycled paper pulp according to claim 4, characterized in that: In the step 2, the mass fraction of the water-soluble polyvinyl alcohol solution is 5-15%, the amount of polyvinyl alcohol solution added to the recovered pulp modified fiber is 0.5-1 ml / g; the mass ratio of the recovered pulp modified fiber, bentonite, and starch is 1-3:0.5-1.5:0.5-1.

5.

7. The method for preparing a submerged plant growth promoting unit using recycled paper pulp according to claim 4, characterized in that: In the step 3, the alkali washing waste liquid is soaked in the medical stone material for 1.5 to 3 hours; and the mass ratio of medical stone to humus soil is 1 to 2:

10.

8. The method for preparing a submerged plant growth promoting unit using recycled paper pulp according to claim 4, characterized in that: In the step 4, the submerged plant pretreatment includes: removing the leaves of the plants that are rotten or in poor growth condition and screening out the withered and rotten plants, and dividing the plants into clumps according to the amount of 5 to 15 plants per clump for later use; the submerged plants are Vallisneria, Potamogeton, Hydrilla, and Potamogeton crispus.

9. The method for preparing a submerged plant growth promoting unit using recycled paper pulp according to claim 4, characterized in that: In the step five, the plant growth-promoting bacteria include Bacillus, nitrogen-fixing bacteria, and Pseudomonas, all of which are powders, with a mass ratio of 1.5-2.5:0.5-1.5:0.5-1.5, and a cell density of the bacteria is 3-4.5 billion / g; the mass ratio of calcium peroxide, planting matrix material, and plant growth-promoting bacteria is 1:8-15:

1.

10. The method for preparing a submerged plant growth promoting unit using recycled paper pulp according to claim 4, characterized in that: In the step six, the planting depth is 3~5cm; the inner diameter of the planting unit shell base is 10~20cm, the upper column height of the planting unit shell base is 5~15cm, the lower vertebral height of the planting unit shell base is 3~8cm, the vertebral height of the planting unit shell cover is 1~5cm, the reserved hole diameter of the planting unit shell cover is 1~3cm, and the width of the gap between the outer wall of the planting unit shell cover and the inner wall of the planting unit shell base is 1~3cm.

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