Water environment treatment material based on composite minerals and aquatic plants as well as preparation method and application of water environment treatment material

Abstract

The invention discloses a water environment treatment material based on composite minerals and aquatic plants and a preparation method and application thereof, and belongs to the technical field of water environment treatment. The water environment treatment material comprises the composite minerals and the aquatic plants, the composite minerals can adsorb and convert heavy metal ions, ammonia nitrogen and organic pollutants, and by combining the absorption of the aquatic plants on nutrient substances and the decomposition effect of microorganisms on the pollutants, the concentration of the pollutants in a water body can be remarkably reduced, and the water quality index is improved; the problems of water eutrophication, heavy metal pollution, organic pollution and the like are effectively solved; the photosynthesis of the aquatic plants can absorb a large amount of carbon dioxide, carbon elements are transferred into the bottom mud for long-term storage, meanwhile, the existence of the complex minerals indirectly promotes the carbon sequestration effect of the aquatic plants, the carbon sequestration capacity of the whole water body ecological system is improved, and finally the multiple purposes of water body pollution treatment, bottom mud remediation, carbon sequestration and sink increase and the like are achieved. The health and the stability of a water body ecological system are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of water environment management, and in particular relates to a water environment management material based on composite minerals and aquatic plants, and a preparation method and application thereof. Background Art

[0002] In the context of severe challenges facing the global environment today, water pollution has become increasingly prominent. Eutrophication, heavy metal pollution, excessive organic pollutants and other phenomena are common in many lakes, rivers, ponds and other water bodies. Traditional water remediation methods, such as physical filtration, chemical treatment and single biological remediation, all have certain limitations. Physical methods are often costly and difficult to fundamentally solve the pollution problem. Chemical methods may introduce new chemicals and cause secondary pollution. Single biological remediation has low efficiency and is greatly affected by environmental factors.

[0003] At the same time, with the increasing attention paid to global climate change, reducing greenhouse gas emissions and increasing carbon sinks have become important tasks in environmental protection. As an important part of the earth's carbon cycle, aquatic ecosystems have huge carbon sequestration potential, but the exploration and enhancement of their carbon sequestration function in the process of water body restoration has not received sufficient attention.

[0004] Aquatic plants have always played an important role in aquatic ecosystems. They absorb carbon dioxide and release oxygen through photosynthesis, which can regulate the chemical balance of water bodies to a certain extent, provide habitats and food sources for aquatic organisms, and absorb and transform nutrients in water bodies. However, relying solely on the natural growth of aquatic plants for water body restoration faces many challenges. For example, in severely polluted water bodies, aquatic plants may have difficulty surviving or grow slowly due to poor water quality, and cannot fully exert their purification and carbon fixation functions. Composite minerals composed of multiple mineral materials have shown broad application prospects in the field of environmental governance due to their diverse physical and chemical properties. However, there are no relevant reports in the existing technology on how to use composite minerals and aquatic plants to achieve water body restoration and carbon fixation and sink enhancement. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a water environment management material based on composite minerals and aquatic plants, and a preparation method and application thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a water environment management material based on composite minerals and aquatic plants, wherein the water environment management material comprises composite minerals and aquatic plants;

[0008] The composite mineral comprises the following raw materials in weight percentages based on the total weight of the composite mineral: 30-50% zeolite, 20-30% bentonite, 10-20% manganese ore and 10-25% limestone;

[0009] The aquatic plants include aquatic plant seeds or aquatic plant plants.

[0010] Preferably, the preparation method of the composite mineral comprises the following steps: weighing each raw material according to weight percentage, mixing and crushing, and then sequentially performing roasting treatment and surface modification to obtain the composite mineral.

[0011] Preferably, the calcination treatment is carried out at a temperature of 400 to 600° C. and for a time of 2 to 4 hours.

[0012] Preferably, the modifier used for the surface modification is an organic surfactant.

[0013] The present invention provides a method for preparing a water environment management material based on composite minerals and aquatic plants as described in the above technical solution, comprising the following steps: uniformly mixing aquatic plant seeds and composite minerals and filling the mixture into a capsule to obtain the water environment management material based on composite minerals and aquatic plants; or,

[0014] The composite mineral is made into a weight to obtain the composite mineral weight; the aquatic plant is bundled with the composite mineral weight to obtain the water environment management material based on the composite mineral and aquatic plant.

[0015] Preferably, the mass ratio of the aquatic grass seeds to the composite minerals is 1:(5-10).

[0016] Preferably, the capsule has a diameter of 2 to 5 mm and a wall thickness of 0.2 to 0.5 mm.

[0017] Preferably, the amount of waterweed seeds filled in the capsule is 3 to 8 seeds per capsule.

[0018] Preferably, the mass of the composite mineral weight is determined according to the size of the aquatic plant and the depth of the water body.

[0019] The present invention also provides the use of the water environment management material based on composite minerals and aquatic plants described in the above technical solution in water environment management and restoration.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] 1. Highly efficient water purification capability: Through the adsorption and transformation of heavy metal ions, ammonia nitrogen and organic pollutants by composite minerals, as well as the absorption of nutrients by aquatic plants and the decomposition of pollutants by microorganisms in the sediment, the concentration of pollutants in the water can be significantly reduced, and water quality indicators can be improved, such as reducing ammonia nitrogen, total phosphorus and COD content, increasing dissolved oxygen levels, and effectively controlling problems such as eutrophication of water bodies, heavy metal pollution and organic pollution.

[0022] 2. Significant carbon fixation and sink effect: Aquatic plants absorb a large amount of carbon dioxide through photosynthesis, and transfer carbon elements to the bottom mud for long-term storage through the growth, death and sedimentation of aquatic plants. At the same time, the presence of complex minerals in the water and bottom mud indirectly promotes the carbon fixation of aquatic plants, improves the carbon fixation capacity of the entire aquatic ecosystem, helps to alleviate the pressure of global climate change, and is of great significance in environmental protection and responding to climate change.

[0023] 3. Sediment restoration and ecological improvement: The precipitation and reaction of composite minerals in the sediment can reduce the risk of nutrient release in the sediment and improve the physical and chemical properties of the sediment, such as increasing porosity and improving air permeability. At the same time, the fixation of the sediment by the roots of aquatic plants and the optimization of the microbial community by their secretions promote the decomposition and transformation of organic pollutants in the sediment, restore the health and stability of the sediment ecosystem, prevent secondary pollution caused by sediment resuspension, and fundamentally improve the ecological environment of the water body.

[0024] 4. Flexible application methods: The present invention provides two ways to combine aquatic plants and composite minerals, which can be selected or combined according to the characteristics of different water bodies, pollution levels and restoration needs. For example, for large-scale water bodies with relatively light pollution, aquatic plant seeds and composite minerals can be encapsulated and placed on a large scale; for areas with severe local pollution or requiring rapid results, composite mineral weights combined with aquatic plants can be used for precise placement and restoration, which improves the applicability and operability of the technology.

[0025] 5. Environmental friendliness and sustainability: The raw materials used are widely available and relatively low in cost. The preparation process of the composite minerals and the combination of aquatic plants and composite minerals are both simple and easy. No new pollutants will be introduced in the process of water restoration. The capsules are made of biodegradable materials, which meets the requirements of environmental protection and sustainable development. It has good application prospects and promotion value and can be widely used in different types of polluted water restoration projects such as lakes, rivers, and ponds. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with specific implementation methods.

[0028] The embodiment of the present invention provides a water environment management material based on composite minerals and aquatic plants, wherein the water environment management material comprises composite minerals and aquatic plants;

[0029] The composite mineral comprises the following raw materials in weight percentages based on the total weight of the composite mineral: 30-50% zeolite, 20-30% bentonite, 10-20% manganese ore and 10-25% limestone;

[0030] The aquatic plants include aquatic plant seeds or aquatic plant plants.

[0031] The composite minerals in the present invention can adsorb and transform heavy metal ions, ammonia nitrogen and organic pollutants. Combined with the absorption of nutrients by aquatic plants and the decomposition of pollutants by microorganisms in the sediment, the concentration of pollutants in the water body can be significantly reduced, water quality indicators can be improved, and problems such as eutrophication of water bodies, heavy metal pollution and organic pollution can be effectively controlled. The photosynthesis of aquatic plants can absorb a large amount of carbon dioxide and transfer carbon elements to the sediment for long-term storage. At the same time, the presence of composite minerals in water bodies and sediments indirectly promotes the carbon fixation of aquatic plants and improves the carbon fixation capacity of the entire water ecosystem, ultimately achieving multiple goals such as water pollution control, sediment restoration, and carbon fixation and sink enhancement, thereby improving the health and stability of the water ecosystem.

[0032] In a preferred embodiment, the composite mineral comprises 30-50% zeolite, more preferably 30-40% zeolite, based on the total weight of the composite mineral. The present invention selects zeolite with high adsorption capacity and selectivity as the main adsorption mineral, and its unique crystal structure can effectively adsorb ammonia nitrogen, heavy metal ions such as lead, cadmium, mercury, etc., and some organic pollutants in water.

[0033] In a preferred embodiment, the composite mineral includes 20-30% bentonite, more preferably 25-30% based on the total weight of the composite mineral. The present invention selects bentonite as the auxiliary adsorption mineral, which has good swelling and adsorption properties, and can further enhance the adsorption capacity of the composite mineral for pollutants, especially for some macromolecular organic pollutants.

[0034] In a preferred embodiment, the composite mineral includes 10-20% manganese ore, more preferably 12-20% manganese ore, based on the total weight of the composite mineral. The addition of manganese ore in the present invention is intended to provide redox activity, and the manganese element contained in it can participate in redox reactions in water bodies, promote the decomposition and transformation of certain refractory organic pollutants, such as having a certain oxidation effect on polycyclic aromatic hydrocarbons.

[0035] In a preferred embodiment, the composite mineral includes 10-25% limestone, more preferably 15-25% limestone, based on the total weight of the composite mineral. The limestone in the present invention, as a calcium source, can not only adjust the pH of the water body to keep it in a range suitable for the growth of aquatic plants and the activity of microorganisms, but also react chemically with phosphorus in the sediment during the sediment remediation process to generate calcium phosphate precipitation, thereby reducing the risk of phosphorus release in the sediment and reducing the potential threat of eutrophication of the water body.

[0036] In a preferred embodiment, the preparation method of the composite mineral comprises the following steps: weighing the raw materials according to weight percentage, mixing and crushing, and then sequentially performing roasting treatment and surface modification to obtain the composite mineral.

[0037] In a preferred embodiment, the pulverization method includes air flow pulverization or ball milling; the ball milling device is a planetary ball mill. The present invention pulverizes the mixed minerals into micron-level or even nanometer-level particle sizes through pulverization, greatly increasing the specific surface area of ​​the minerals, thereby significantly improving their adsorption and reaction activity.

[0038] In a preferred embodiment, the average particle size of the mixed mineral after crushing is 300nm-10μm, more preferably 500nm-5μm. The specific surface area of ​​the mixed mineral after crushing can reach tens of square meters per gram. Compared with the uncrushed mineral raw materials, the adsorption capacity of ammonia nitrogen can be increased by 3-5 times, and the adsorption rate of heavy metal ions can be increased by 2-4 times.

[0039] In a preferred embodiment, the temperature of the roasting treatment is 400-600°C, more preferably 450-550°C; the time of the roasting treatment is 2-4h, more preferably 2.5-3h. During the roasting process, the high temperature can cause the crystal structure inside the mineral to adjust and optimize, remove some impurities and moisture, and further activate the physical and chemical properties of the mineral. The zeolite crystal structure after roasting is more stable, its internal pore structure is unblocked and expanded, and the adsorption selectivity and capacity of ammonia nitrogen are further enhanced; the manganese element in the manganese ore undergoes an oxidation state change at high temperature, which significantly improves its redox activity and can more effectively catalyze the oxidation reaction of organic pollutants.

[0040] In a preferred embodiment, the modifier used for the surface modification is an organic surfactant; the organic surfactant includes hexadecyltrimethylammonium bromide (CTAB) or sodium dodecylbenzene sulfonate (SDBS). The present invention covers the surface of the mineral with surfactant molecules through surface modification, giving it a specific charge or functional group, greatly improving the dispersibility and stability of the composite mineral in the water body, preventing it from agglomerating and settling, and enhancing the selective adsorption capacity for specific pollutants. The dispersion time of the composite mineral modified by CTAB in the water body can be extended by 5 to 8 hours, and the adsorption selectivity coefficient for heavy metal ions can be increased by 2 to 3 times.

[0041] In a preferred embodiment, the organic surfactant is added in the form of a solution; the concentration of the organic surfactant solution is 0.002 wt%; the dosage ratio of the organic surfactant solution to the zeolite is (50-100) L: (30-50) kg.

[0042] In a preferred embodiment, the surface modification time is 1 to 2 hours.

[0043] In a preferred embodiment, the aquatic plants include one or more of Vallisneria, Myriophyllum, and Hydrilla. The present invention selects the above aquatic plants, which have strong adaptability and high photosynthetic efficiency, and have good performance in water body restoration and carbon fixation.

[0044] The present invention provides a method for preparing the water environment management material based on composite minerals and aquatic plants as described in the above technical solution, comprising the following steps: uniformly mixing aquatic plant seeds and composite minerals and filling the mixture into a capsule to obtain the water environment management material based on composite minerals and aquatic plants (capsule material); or,

[0045] The composite mineral is made into a weight to obtain the composite mineral weight; the aquatic plant is bundled with the composite mineral weight to obtain the water environment management material (weight material) based on the composite mineral and aquatic plant.

[0046] The present invention combines the composite minerals and aquatic plants into water environment management materials based on composite minerals and aquatic plants by encapsulating aquatic plant seeds and composite minerals or by bundling the composite minerals with aquatic plants as weights, thereby giving full play to the advantages of both, achieving water purification, bottom sediment repair and significant carbon fixation and sink effects, and achieving the dual goals of reducing pollution and carbon emissions.

[0047] In a preferred embodiment, the mass ratio of the aquatic grass seeds to the composite minerals is 1:(5-10).

[0048] In a preferred embodiment, the water grass seeds further include a pretreatment step before being mixed with the composite minerals; the pretreatment includes disinfection and soaking to accelerate germination. The present invention improves the germination rate and survival rate of the water grass seeds through pretreatment.

[0049] In a preferred embodiment, the material for preparing the capsule includes polylactic acid (PLA) or polyhydroxyalkanoate (PHA). The present invention selects biodegradable polymer materials as the shell material of the capsule. These materials have good biocompatibility and degradability, and can be gradually decomposed into harmless small molecules in the water environment without causing secondary pollution to the water.

[0050] In a preferred embodiment, the diameter of the capsule is 2-5 mm; the wall thickness of the capsule is 0.2-0.5 mm; and the shape of the capsule is spherical or elliptical. The present invention controls the wall thickness of the capsule within the above range, which not only ensures sufficient mechanical strength to protect the waterweed seeds and composite minerals inside, but also ensures that the capsule can be degraded and broken within a suitable time to release the waterweed seeds and composite minerals.

[0051] In a preferred embodiment, the amount of waterweed seeds filled in the capsule is 3 to 8 seeds / capsule. In a preferred embodiment of the present invention, the amount of waterweed seeds filled in each capsule is determined according to the reproduction characteristics and placement density of the waterweed.

[0052] In a preferred embodiment, the mass of the composite mineral weight is determined according to the size of the aquatic plant and the depth of the water body; further preferably, the mass of the composite mineral weight is 10 to 50 g. For deeper water bodies and larger aquatic plants, a composite mineral weight with a larger mass can be selected to ensure that the aquatic plant can be stably rooted at the bottom of the water body.

[0053] In a preferred embodiment, the composite mineral weight has a spherical, cylindrical or block shape. In a preferred embodiment of the present invention, during the processing of the composite mineral weight, small holes or grooves can be provided on the composite mineral weight so as to be tied and connected with the aquatic plants.

[0054] In a preferred embodiment, the binding is made of thin rope or degradable fiber material; the binding position of the water grass plant is the root or stem. When binding, care should be taken to avoid damaging the tissue of the water grass plant, and at the same time ensure that the composite mineral weight can be stably suspended under the water grass plant.

[0055] The present invention also provides the use of the water environment management material based on composite minerals and aquatic plants described in the above technical solution in water environment management and restoration.

[0056] In a preferred embodiment, when the water environment management material based on composite minerals and aquatic plants is a capsule material, the placement density of the capsule material is determined according to the water body area, pollution degree and target restoration effect; further preferably, the placement density of the capsule material is 30 to 100 capsules / m 2 .

[0057] The action process of capsule materials: After the capsule materials are placed in the water body to be repaired, the capsule materials gradually settle in the water body. Because their density is slightly greater than that of water, they will be evenly distributed at the bottom of the water body and in different water layers under the action of gravity. During the sedimentation process, the capsule shell can protect the water grass seeds inside from the direct impact of pollutants and water flow in the water body. As time goes by, under suitable water temperature, light and other conditions, the capsule shell begins to gradually degrade. After a period of time, generally 3 to 7 days, the capsule breaks, releasing the water grass seeds and composite minerals inside. At this time, the composite minerals immediately exert their adsorption and reaction activity, quickly adsorbing heavy metal ions, ammonia nitrogen and organic pollutants in the surrounding water body, reducing the pollution concentration of the local water body, and creating a relatively clean microenvironment for the germination of water grass seeds and the growth of seedlings. For example, in a pond with severe pollution, after the capsule material filled with Vallisneria seeds is placed, the ammonia nitrogen concentration in the water body around the capsule material can be reduced by 30 to 50% within 24 hours, and the heavy metal ion concentration can be reduced by 20 to 40%, providing favorable conditions for the germination of Vallisneria seeds.

[0058] Subsequently, the waterweed seeds begin to germinate and grow into seedlings in a suitable environment. The waterweed seedlings absorb nutrients in the water body, including nitrogen, phosphorus and other elements, through their roots for their own growth and development, thereby further reducing the eutrophication of the water body. At the same time, the photosynthesis of waterweeds gradually increases, absorbing a large amount of carbon dioxide in the water body and releasing oxygen. The release of oxygen increases the dissolved oxygen content in the water body, which on the one hand promotes the growth and reproduction of aerobic microorganisms and accelerates the decomposition and transformation of organic pollutants; on the other hand, it increases the redox potential of the water body, allowing the redox active components in the composite minerals to play a better role, further enhancing the removal effect of pollutants. For example, during the vigorous growth period of waterweeds, the dissolved oxygen content in the water body can be increased by 2 to 3 times, and the chemical oxygen demand (COD) can be reduced by 40 to 60%. At the same time, as the waterweed grows, its roots gradually penetrate into the bottom mud, fix the bottom mud particles, prevent the bottom mud from re-suspension, and some organic substances and enzymes secreted by the roots can promote the optimization and activity of the microbial community in the bottom mud, accelerate the decomposition of organic pollutants in the bottom mud and the recycling of nutrients. Some aquatic plants will die and settle into the mud during their growth process. The remains of these aquatic plants are decomposed and transformed by microorganisms in the mud. The carbon elements in them are sealed in the mud for a long time, achieving carbon fixation and storage. At the same time, it also provides a carbon source for the microorganisms in the mud, promoting the stability and healthy development of the mud ecosystem.

[0059] In a preferred embodiment, when the water environment management material based on composite minerals and aquatic plants is a weight material, the placement density of the weight material is determined according to the water area, water depth, pollution degree and target restoration effect; further preferably, the placement density of the weight material is 30 to 50 plants / m 2 .

[0060] The working process of the weight material: After the weight material is placed in the water body to be repaired, the weight material sinks rapidly under the action of gravity, and drives the aquatic plants to sink to the bottom of the water body. During the sinking process, the composite mineral weight begins to absorb pollutants in the water body, especially in the water layer near the bottom. It has a strong adsorption capacity for heavy metal ions, ammonia nitrogen and organic pollutants, and can effectively reduce the pollution level in this area. For example, in the sediment pollution area of ​​the river, after the foxtail algae with composite mineral weights are placed, the heavy metal ion concentration in the water body above the sediment can be reduced by 25-40% within 1 week, and the ammonia nitrogen concentration can be reduced by 30-50%.

[0061] After the waterweed plants have taken root stably at the bottom of the water body, they begin to photosynthesize and absorb nutrients. The oxygen produced by their photosynthesis diffuses through the water around the roots, increasing the dissolved oxygen content of the local water body, promoting the growth of microorganisms and the decomposition of pollutants. At the same time, the waterweed plants absorb nutrients such as nitrogen and phosphorus in the water body, reducing the eutrophication level of the water body, and the substances secreted by their roots can improve the physical and chemical properties of the bottom mud, increase the air permeability and microbial activity of the bottom mud. For example, during the growth of the black algae plants, the porosity of the bottom mud around its roots can be increased by 20-30%, and the number of microorganisms can be increased by 1-2 orders of magnitude.

[0062] As time goes by, the long-term presence of composite mineral weights in water bodies and sediments continues to play an adsorption and reaction role. The adsorbed pollutants may be further transformed and degraded under the action of microorganisms, and some are fixed on the surface or inside of the minerals. At the same time, composite minerals react chemically with substances in the sediment. For example, the reaction of limestone and phosphorus reduces the risk of phosphorus release in the sediment and stabilizes the sediment ecological environment. Water grass plants also fix carbon during their growth, converting carbon dioxide into organic matter and storing it in their bodies. Some organic matter enters the sediment with the death and sedimentation of water grass plants. After being decomposed and transformed by microorganisms in the sediment, the carbon element is sealed in the sediment for a long time, realizing the carbon cycle between water bodies, water grasses and sediments and the effect of carbon fixation and sink.

[0063] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0064] Example 1

[0065] A preparation method of a water environment management material based on composite minerals and aquatic plants:

[0066] (1) 40 kg of zeolite, 25 kg of bentonite, 15 kg of manganese ore and 20 kg of limestone were weighed respectively according to the mass ratio of zeolite: bentonite: manganese ore: limestone = 40%: 25%: 15%: 20%; the above mineral raw materials were placed in a planetary ball mill for mixed grinding, and the grinding was carried out for 3 hours to make the average particle size of the mineral reach 5 μm; then the ground mixed mineral was placed in a muffle furnace, roasted at 500° C. for 3 hours, cooled, and then 100 L of hexadecyltrimethylammonium bromide solution with a concentration of 0.002wt% was added for surface modification treatment, and the modification was carried out for 1.5 hours, and the mixture was repeatedly rinsed with deionized water until neutral, and dried to obtain a composite mineral.

[0067] (2) Polylactic acid (PLA) was selected as the capsule shell material to prepare spherical capsules with a diameter of 3 mm and a wall thickness of 0.3 mm.

[0068] (3) The Vallisneria seeds are disinfected and soaked for germination, and then mixed with the composite mineral prepared in step (1) at a mass ratio of 1:8, and then filled into the spherical capsules prepared in step (2) to obtain a water environment management material (capsule material) based on the composite mineral and aquatic plants; wherein the filling amount of the Vallisneria seeds in the capsule is 5 seeds / piece.

[0069] In an area of ​​100m 2 In the test pond with a water depth of 2m, 50 / m 2 The capsule material prepared in Example 1 was placed at a density of, and the pond water quality was regularly monitored. The monitoring indicators included ammonia nitrogen, total phosphorus, chemical oxygen demand (COD), and dissolved oxygen. At the same time, the changes in carbon content in the water body and sediment were monitored, and the growth of aquatic plants and changes in the sediment were observed.

[0070] After 5 months of restoration experiments, the results showed that the ammonia nitrogen concentration in the pond water was reduced from the initial 5 mg / L to below 0.8 mg / L, the total phosphorus concentration was reduced from 1.5 mg / L to about 0.2 mg / L, the COD was reduced from 80 mg / L to about 25 mg / L, and the dissolved oxygen content was increased from 3 mg / L to above 6.5 mg / L. Vallisneria grew vigorously, with a coverage of more than 65% of the bottom area of ​​the pond. The phosphorus content in the sediment was significantly reduced, the sediment structure was improved, and the microbial activity was enhanced. The total carbon content in the water body was reduced by 32% compared with that before restoration, of which about 42% of the carbon was absorbed and fixed by the aquatic plants and settled into the sediment with the aquatic plant residues. The organic carbon content in the sediment increased by 28% compared with the initial level, indicating that the water environment management material provided by the present invention achieves a significant carbon fixation and sink effect while repairing the water body.

[0071] Example 2

[0072] A preparation method of a water environment management material based on composite minerals and aquatic plants:

[0073] (1) 35 kg of zeolite, 28 kg of bentonite, 12 kg of manganese ore and 25 kg of limestone were weighed according to the mass ratio of zeolite: bentonite: manganese ore: limestone = 35%: 28%: 12%: 25% respectively; the above mineral raw materials were mixed and crushed to an average particle size of 3 μm by air flow milling method, and then placed in a muffle furnace, roasted at 450° C. for 4 hours, cooled, and then 100 L of sodium dodecylbenzene sulfonate solution with a concentration of 0.002wt% was added for surface modification treatment, modified for 2 hours, repeatedly rinsed with deionized water until neutral, and dried to obtain a composite mineral.

[0074] (2) Processing the composite mineral prepared in step (1) into a cylindrical weight with a mass of 20 grams, and setting a small hole on the weight, and then firmly tying the composite mineral weight and the root of foxtail algae with a degradable fiber rope to obtain a water environment management material (weight material) based on the composite mineral and aquatic plants.

[0075] In an area of ​​80m 2 In a test pond with a water depth of 1.5 m, 50 plants / m 2 The sinker material prepared in Example 2 was placed at a placement density of, and the water quality of the pond was monitored regularly. The monitoring indicators included ammonia nitrogen, total phosphorus, chemical oxygen demand (COD), and dissolved oxygen. At the same time, the changes in carbon content in the water body and bottom mud were monitored, and the growth of aquatic plants and changes in the bottom mud were observed.

[0076] After 6 months of restoration experiments, the results showed that the ammonia nitrogen concentration in the pool water dropped from the initial 6 mg / L to 0.6 mg / L, the total phosphorus concentration dropped from 1.8 mg / L to 0.15 mg / L, the COD dropped from 90 mg / L to 20 mg / L, and the dissolved oxygen content increased from 2.5 mg / L to 7.5 mg / L. Foxtail algae grew densely, covering an area of ​​about 75%. The phosphorus content in the sediment was significantly reduced, the sediment texture was loose, and the microbial diversity increased. In terms of carbon fixation, the total carbon content in the water body was reduced by 38%, of which 48% was fixed by aquatic plants and transferred to the sediment, and the organic carbon content in the sediment increased by 33% compared with the initial level, further proving the carbon fixation and carbon sink enhancement ability of the water environment management material provided by the present invention and the restoration effect on water bodies and sediments.

[0077] Example 3

[0078] A preparation method of a water environment management material based on composite minerals and aquatic plants:

[0079] (1) 30 kg of zeolite, 30 kg of bentonite, 20 kg of manganese ore and 20 kg of limestone were weighed respectively according to the mass ratio of zeolite: bentonite: manganese ore: limestone = 30%: 30%: 20%: 20%; the above mineral raw materials were placed in a planetary ball mill for mixed grinding, and the grinding was carried out for 2 hours to make the average particle size of the mineral reach 500 nm; then the ground mixed mineral was placed in a muffle furnace, roasted at 550° C. for 2.5 hours, cooled, and then 100 L of 0.002 wt% octadecyltrimethylammonium chloride solution was added for surface modification treatment, and the modification was carried out for 1 hour, and the mixture was repeatedly rinsed with deionized water until neutral, and dried to obtain a composite mineral.

[0080] (2) Polylactic acid (PLA) was selected as the capsule shell material to prepare spherical capsules with a diameter of 4 mm and a wall thickness of 0.4 mm.

[0081] (3) The black algae seeds are disinfected and soaked for germination, and then mixed with the composite mineral prepared in step (1) at a mass ratio of 1:6, and then filled into the spherical capsule prepared in step (2) to obtain a water environment management material (capsule material) based on the composite mineral and aquatic plants; wherein the filling amount of the black algae seeds in the capsule is 4 seeds / capsule.

[0082] In an area of ​​120m 2 Two groups of comparative experiments were set up in a local area of ​​the test lake with a water depth of 2.5m. One group was set at 60 / m 2 The capsule material prepared in Example 3 was placed at a density of 100 capsules / m 2 The capsule material prepared in Example 3 was placed at a placement density of, and the water quality in the test area was regularly monitored. The monitoring indicators included ammonia nitrogen, total phosphorus, chemical oxygen demand (COD), and dissolved oxygen. At the same time, the changes in carbon content in the water body and sediment were monitored, and the growth of aquatic plants and changes in the sediment were observed.

[0083] After 7 months of observation and analysis, at 60 / m 2 In the area where the water was released, the concentration of ammonia nitrogen in the water body dropped from 4.5mg / L to 0.5mg / L, the concentration of total phosphorus dropped from 1.2mg / L to 0.12mg / L, the COD dropped from 70mg / L to 18mg / L, and the dissolved oxygen content increased from 3.2mg / L to 8.2mg / L. The growth of black algae is good, with a coverage rate of 72%. The release of phosphorus in the sediment has been effectively curbed, and the sediment ecology has gradually recovered. From the carbon fixation data, the carbon content in the water body decreased by 25%, the proportion of carbon fixed by aquatic plants and transferred to the sediment reached 35%, and the organic carbon content in the sediment increased by 20%.

[0084] At 100 / m 2In the area where the water was released, the concentration of ammonia nitrogen in the water body dropped to 0.4mg / L, the concentration of total phosphorus dropped to 0.1mg / L, the COD dropped to 15mg / L, and the dissolved oxygen content increased to 8.5mg / L. The coverage rate of black algae reached 80%, the carbon content of the water body decreased by 30%, the proportion of carbon fixed by aquatic plants transferred to the bottom mud reached 40%, and the organic carbon content in the bottom mud increased by 25%, indicating that appropriately increasing the release density can improve the restoration effect to a certain extent, but the improvement effect is not significant, so it is necessary to comprehensively consider factors such as cost for reasonable release.

[0085] Comparative Example 1

[0086] Steps (1) to (2) are the same as in Example 1;

[0087] (3) Filling the composite mineral prepared in step (1) into the spherical capsule prepared in step (2), wherein the filling amount of the composite mineral in the capsule is 20 g / capsule.

[0088] Comparative Example 2

[0089] Polylactic acid (PLA) was selected as the capsule shell material to prepare spherical capsules with a diameter of 3 mm and a wall thickness of 0.3 mm; Vallisneria seeds were sterilized and soaked for germination, and then filled into the spherical capsules at a filling amount of 5 seeds per capsule to obtain seed capsules.

[0090] Comparative Example 3

[0091] The difference from Example 1 is that in step (1), 48 kg of zeolite, 28 kg of bentonite and 24 kg of limestone are weighed respectively according to the mass ratio of zeolite: bentonite: limestone = 48%: 28%: 24%, and the rest is the same as Example 1.

[0092] Comparative Example 4

[0093] (1) 40 kg of zeolite, 25 kg of bentonite, 15 kg of manganese ore and 20 kg of limestone were weighed respectively according to the mass ratio of zeolite: bentonite: manganese ore: limestone = 40%: 25%: 15%: 20%; the above mineral raw materials were mixed and placed in a muffle furnace, roasted at 500° C. for 3 hours, cooled, and then 100 L of 0.002 wt% hexadecyltrimethylammonium bromide solution was added for surface modification treatment for 1.5 hours, and the surface was repeatedly rinsed with deionized water until neutral, and dried to obtain a composite mineral.

[0094] Steps (2) to (3) are the same as those in Example 1.

[0095] Comparative Example 5

[0096] (1) 40 kg of zeolite, 25 kg of bentonite, 15 kg of manganese ore and 20 kg of limestone were weighed respectively according to the mass ratio of zeolite: bentonite: manganese ore: limestone = 40%: 25%: 15%: 20%; the above mineral raw materials were placed in a planetary ball mill for mixed grinding, and the grinding was carried out for 3 hours to make the average particle size of the mineral reach 5 μm; then 100 L of hexadecyltrimethylammonium bromide solution with a concentration of 0.002wt% was added for surface modification treatment, and the modification was carried out for 1.5 hours, and the surface was repeatedly rinsed with deionized water until neutral, and dried to obtain a composite mineral.

[0097] Steps (2) to (3) are the same as those in Example 1.

[0098] Comparative Example 6

[0099] (1) 40 kg of zeolite, 25 kg of bentonite, 15 kg of manganese ore and 20 kg of limestone were weighed respectively according to the mass ratio of zeolite: bentonite: manganese ore: limestone = 40%: 25%: 15%: 20%; the above mineral raw materials were placed in a planetary ball mill for mixed grinding, and the grinding was carried out for 3 hours until the average particle size of the mineral reached 5 μm; then the ground mixed mineral was placed in a muffle furnace, roasted at 500° C. for 3 hours, and cooled to obtain a composite mineral.

[0100] Steps (2) to (3) are the same as those in Example 1.

[0101] In an area of ​​100m 2 , in a test pond with a water depth of 2m, 6 test areas were set up, with 50 / m 2 The capsule materials prepared in Comparative Examples 1 to 6 were placed at a density of respectively. The water quality of the pond was monitored after 5 months. The monitoring indicators included ammonia nitrogen, total phosphorus, chemical oxygen demand (COD), and dissolved oxygen. At the same time, the changes in carbon content in the water body and sediment were monitored, and the growth of aquatic plants and changes in sediment were observed. The results are shown in Table 1.

[0102] Table 1 Repair effect of capsule materials prepared in Comparative Examples 1 to 6

[0103]

[0104]

[0105] As can be seen from Table 1, the capsule material made of composite minerals alone (Comparative Example 1) has increased ammonia nitrogen, total phosphorus, and COD concentrations in the repaired water body compared to Example 1, and the dissolved oxygen content has decreased. In addition, due to the lack of germination of aquatic grass seeds and growth of plant communities, the total carbon in the water body has decreased, and the release of organic carbon in the sediment has decreased. The capsule material made of aquatic grass seeds alone (Comparative Example 2) has a higher concentration of pollutants in the repaired water body compared to Example 1. Although aquatic grass seeds are added, the capsule material lacks composite minerals. The material floats easily and cannot settle on the bottom mud. The seed germination rate is very low, the aquatic plant coverage is only 10%, the dissolved oxygen and other improvements are limited, and the increase in bottom mud organic carbon is low. Compared with Example 1, Comparative Example 3 lacks manganese ore in the raw material composition of the composite mineral, which affects the degradation effect of the capsule material on organic matter in the water body and the coverage of aquatic plants. The preparation process of the composite mineral is changed (Comparative Examples 4 to 6). Compared with Example 1, the concentrations of ammonia nitrogen, total phosphorus and COD in the repaired water body are increased to a certain extent, which also affects the carbon fixation efficiency of the bottom mud.

[0106] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A water environment management material based on composite minerals and aquatic plants, characterized in that: The water environment treatment materials include composite minerals and aquatic plants; The composite mineral comprises the following raw materials in weight percentages based on the total weight of the composite mineral: 30-50% zeolite, 20-30% bentonite, 10-20% manganese ore and 10-25% limestone; The aquatic plants include aquatic plant seeds or aquatic plant plants.

2. The water environment management material based on composite minerals and aquatic plants according to claim 1 is characterized in that: The preparation method of the composite mineral comprises the following steps: weighing various raw materials according to weight percentage, mixing and crushing them, and then performing roasting treatment and surface modification in sequence to obtain the composite mineral.

3. The water environment management material based on composite minerals and aquatic plants according to claim 2 is characterized in that: The calcination process is carried out at a temperature of 400 to 600° C. and for a time of 2 to 4 hours.

4. The water environment management material based on composite minerals and aquatic plants according to claim 2 is characterized in that: The modifier used for the surface modification is an organic surfactant.

5. The method for preparing the water environment management material based on composite minerals and aquatic plants according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: mixing water grass seeds and composite minerals uniformly and filling the mixture into capsules to obtain the water environment management material based on composite minerals and water grasses; or, The composite mineral is made into a weight to obtain the composite mineral weight; the aquatic plant is bundled with the composite mineral weight to obtain the water environment management material based on the composite mineral and aquatic plant.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the aquatic grass seeds to the composite minerals is 1:(5-10).

7. The preparation method according to claim 5, characterized in that: The capsule has a diameter of 2 to 5 mm and a wall thickness of 0.2 to 0.5 mm.

8. The preparation method according to claim 5, characterized in that: The filling amount of the waterweed seeds in the capsule is 3 to 8 seeds per capsule.

9. The preparation method according to claim 5, characterized in that: The mass of the composite mineral weight is determined according to the size of the aquatic plant and the depth of the water body.

10. Use of the water environment management material based on composite minerals and aquatic plants as described in any one of claims 1 to 4 in water environment management and restoration.

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