Submerged plant water throwing and planting material with oxygen slow-release function and preparation method thereof

Abstract

The present application belongs to the field of environmental remediation technology, and particularly relates to a submerged plant water-carrying throwing planting material with oxygen slow-release function and a preparation method thereof. The material is composed of aggregate, cementing material, admixture, functional additive and water, and the mass ratio of the aggregate, cementing material, admixture, functional additive and water is (60-80):(5-15):(5-10):(5-15):(35-45). The aggregate is made of biomass powder and dehydrated bottom mud by anaerobic co-pyrolysis, and the mass ratio of the biomass powder and the dehydrated bottom mud is (5-10):100. The throwing planting material can effectively realize water-carrying throwing planting operation of the submerged plant, and the functional additive in the throwing planting material can slow-release oxygen, thereby effectively improving the oxygenation capacity of the water area.

Description

Technical Field

[0001] This invention belongs to the field of environmental remediation technology, and in particular relates to a submerged plant material with oxygen slow-release function and its preparation method. Background Technology

[0002] The construction and restoration of submerged plant communities is an important aspect of aquatic ecological restoration. Currently, the planting of submerged plants in projects mainly adopts dry methods, which involves first draining the water area to be restored, improving the bottom sediment, and then planting submerged plants. To ensure the survival rate of submerged plants, it is generally necessary to temporarily impound water or introduce zooplankton to maintain water transparency.

[0003] However, in aquatic ecological restoration projects, it is often encountered that some water bodies face difficulties in dewatering and have high water flow velocities. Therefore, the common methods are pole planting or direct planting. Pole planting involves inserting the roots of submerged plants directly into the bottom sediment using a fork. However, this method can easily pull out the submerged plant when removing the pole. Direct planting involves wrapping the roots of submerged plants with soil or heavy blocks to allow them to sink to the bottom and establish roots. However, the soil's binding force weakens after being soaked in water, causing the submerged plant to float. Using hard, heavy blocks to bind the plants hinders their rooting into the bottom sediment, and a large number of hard, heavy blocks sinking to the bottom can disrupt the underwater ecosystem.

[0004] Therefore, both the stake planting method and the traditional throwing method are limited by their own technology and cannot guarantee the survival rate of submerged plants. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a submerged plant planting material with oxygen-releasing function and its preparation method. This invention can effectively achieve the planting of submerged plants with water and can also release oxygen slowly, effectively improving the reoxygenation capacity of water bodies.

[0006] To achieve one of the above objectives, the present invention adopts the following technical solution:

[0007] A submerged plant planting material with oxygen slow-release function is provided. The material is composed of aggregate, cementitious material, admixture, functional additives and water. The mass ratio of aggregate, cementitious material, admixture, functional additives and water is (60-80):(5-15):(5-10):(5-15):(35-45). The aggregate is made by anoxic co-pyrolysis of biomass powder and dewatered bottom sediment. The mass ratio of biomass powder and dewatered bottom sediment is (5-10):100.

[0008] Preferably, the mass ratio of aggregate, cementitious material, admixture, functional additive, and water is 80:5:5:10:40.

[0009] Preferably, the biomass powder is one or a combination of two or more of the following: Vallisneria natans, Ceratophyllum demersum, Potamogeton crispus, Hydrilla verticillata, Reed, Thalia dealbata, Typha orientalis, Canna indica, Lythrum salicaria, Alpinia galbana, and Alternanthera philoxeroides; the particle size of the biomass powder is ≤0.125mm; and the particle size of the dewatered sediment is ≤2.0mm.

[0010] Preferably, the gel material is general-purpose silicate cement, including silicate cement, ordinary silicate cement, slag silicate cement and pozzolanic silicate cement, etc., and the particle size of the gel material is ≤0.125mm.

[0011] Preferably, the admixture is one or a combination of two or more of the following: fly ash, granulated blast furnace slag powder, silica fume, and natural pozzolanic material, and the particle size of the admixture is ≤0.125mm.

[0012] Preferably, the functional admixture is calcium peroxide.

[0013] Preferably, the temperature for co-pyrolysis of biomass powder and dehydrated sediment is 400-600℃.

[0014] Preferably, the planting material is in the form of ring blocks.

[0015] To achieve the second objective mentioned above, this invention provides a method for preparing a submerged plant planting material with oxygen-releasing function, comprising the following specific steps:

[0016] S1. The water-containing bottom mud is subjected to dehydration, solidification, air drying, impurity removal and compaction in sequence to obtain dehydrated bottom mud;

[0017] S2. Mix the washed and dried biomass powder with the dehydrated bottom mud in proportion, and carry out co-pyrolysis at a temperature of 400-600℃ under anaerobic conditions. After cooling, the aggregate is obtained.

[0018] S3. Weigh out the aggregate, cementitious material, admixture, functional additives and water in each mass fraction, mix them and place them in a mold to compact and shape them. After standard curing until initial setting, demold them and let them air dry naturally to obtain the submerged plant material with water.

[0019] Specifically, the raw materials are thoroughly mixed in a mixer to obtain a slurry. The slurry is then poured into a PVC mold, and mechanical vibration is used to remove any trapped air bubbles. After standard curing until the sample initially sets, it is demolded and then air-dried to obtain the submerged plant planting ring material. The PVC mold has an inner diameter of 2-3 cm and an outer diameter of 5-6 cm, with a ring thickness of 2-3 cm. The standard curing temperature is (20±1)℃, and the relative humidity is ≥90%.

[0020] Preferably, in step S1, the moisture content of the dewatered sediment is 15%-30%; the dewatered sediment refers to the solidified sediment obtained after the sediment has been dewatered. The dewatering and solidification method is determined according to the dredging method, and can be sun-drying, tilling or mechanical pressure filtration for dewatering and solidification.

[0021] Preferably, in step S2, the mixed biomass powder and dehydrated bottom mud are placed in a crucible, compacted, sealed, and then placed in a muffle furnace for co-pyrolysis for 1-3 hours.

[0022] The advantages of this invention are:

[0023] (1) This invention improves the dehydrated bottom sediment by high-temperature co-pyrolysis, avoiding secondary pollution of water bodies caused by bottom sediment reuse. It is not only low in preparation cost and simple to operate, but also has a certain oxygen release function in the submerged plant planting material, realizing the water-bearing planting of submerged plants, and improving the dissolved oxygen at the mud-water interface during the rooting period of submerged plants. It can also play a role in the resource utilization of bottom sediment.

[0024] (2) The preparation method of this invention first improves the dehydrated sediment through co-pyrolysis, then uses the improved sediment as aggregate, adds appropriate amounts of cement and functional additives, and mixes them in a certain proportion. The mixture is then molded into ring-shaped blocks with inner and outer diameters of 2-3 cm and 5-6 cm, respectively, and dried at high temperature to obtain submerged plant planting ring block material. The prepared ring block material not only enables the water-based planting of submerged plants, but also effectively increases the dissolved oxygen content at the mud-water interface, improves the survival rate of submerged plants, and simultaneously realizes the resource utilization of the sediment.

[0025] (3) In view of the problem of planting submerged plants in waters with high water flow velocity and inability to achieve drainage in the existing technology, the present invention provides a method for preparing a submerged plant planting material based on bottom sediment improvement and reuse. On the one hand, by improving and modifying the bottom sediment and performing secondary shaping, the survival rate of submerged plant planting can be improved. On the other hand, using the improved bottom sediment as aggregate to synthesize materials for the planting of submerged plants can not only increase the dissolved oxygen at the mud-water interface in the short term, but also solve the problem of subsequent bottom sediment treatment.

[0026] (4) The present invention uses a mixture of high-temperature anaerobic co-heat dewatering sediment and biomass powder. The organic pollutants and microorganisms accumulated in the sediment will decompose at high temperature. At the same time, the pyrolysis gas of the biomass powder has a certain pore-forming effect on the dewatered sediment, while the carbonized substances after pyrolysis are stored in the dewatered sediment. At this time, the dewatered sediment is rich in nutrients such as carbon, potassium, nitrogen, and phosphorus, which can provide nutrients for submerged plants and improve the sediment.

[0027] (5) In this invention, a certain amount of functional admixture is added to the aggregate and the aggregate is shaped into rings. When the submerged plants are thrown into the bottom of the water along with the rings, the CaO2 in the rings undergoes an oxidation-reduction reaction through contact with the mud-water interface and releases O2, increasing the dissolved oxygen concentration at the mud-water interface. This helps benthic animals to flocculate or feed on suspended particles and algae to a certain extent, thereby improving the water transparency. The generated Ca(OH)2 further enhances the self-gelling properties of the cementing materials and admixtures, allowing the rings to remain in the water for a longer period of time until the submerged plants take root in the bottom mud. This also delays the contact between the CaO2 inside the rings and the mud-water interface, ensuring the slow release of O2 from the ring material.

[0028] (6) This invention effectively utilizes bottom sediment and waste biomass, which is not only environmentally friendly, but also enables the planting of submerged plants in water, improving the survival ability of submerged plants in high-velocity water bodies. Moreover, the functional additives in the planting material can play a role in slow-release oxygen, effectively improving the reoxygenation capacity of the water area. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the manufacturing process of the implantable ring block material of this invention.

[0030] Figure 2 The graph shows the change in dissolved oxygen concentration in water of the water-bearing planting materials prepared in Example 1 and Comparative Examples 1-2 of this invention as a function of the immersion time of the planting rings. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] Example 1

[0033] A submerged plant planting material with oxygen slow-release function, the raw materials of which include 80 parts by weight of aggregate, 5 parts by weight of silicate cement, 5 parts by weight of fly ash, 10 parts by weight of calcium peroxide, and 40 parts by weight of water.

[0034] The aggregate is prepared by thoroughly mixing 1000 parts by weight of dehydrated bottom mud with a particle size ≤2mm and 100 parts by weight of reed powder with a particle size ≤0.125mm, pyrolyzing it in a muffle furnace at 500℃ in an oxygen-deficient environment for 2 hours, and then cooling it.

[0035] The specific steps for preparing the above-mentioned submerged plant planting material with oxygen slow-release function are as follows:

[0036] After the aggregate, silicate cement, fly ash and calcium peroxide are thoroughly mixed, 40 parts by weight of deionized water are added and stirred evenly. The slurry is poured into a PVC mold, and mechanical vibration is used to remove the trapped air bubbles inside. After standard curing until the sample initially sets, it is demolded and air-dried naturally to obtain a ring-shaped submerged planter material 1.

[0037] The PVC mold has an outer diameter of 5cm, an inner diameter of 2cm, and a ring block thickness of 2cm.

[0038] Example 2

[0039] A submerged plant planting material with oxygen slow-release function, the raw materials of which include 60 parts by weight of aggregate, 10 parts by weight of silicate cement, 5 parts by weight of fly ash, 15 parts by weight of calcium peroxide, and 35 parts by weight of water.

[0040] The aggregate is prepared by thoroughly mixing 1000 parts by weight of dehydrated bottom mud with a particle size ≤2mm and 75 parts by weight of reed powder with a particle size ≤0.125mm, pyrolyzing it in a muffle furnace at 400℃ in an oxygen-deficient environment for 2 hours, and then cooling it.

[0041] The specific steps of the above-mentioned method for preparing a submerged plant planting material with oxygen slow-release function are as follows:

[0042] After the aggregate, silicate cement, fly ash and calcium peroxide are thoroughly mixed, 40 parts by weight of deionized water are added and stirred evenly. The slurry is poured into a PVC mold, and mechanical vibration is used to remove the trapped air bubbles inside. After standard curing until the sample initially sets, it is demolded and air-dried naturally to obtain a ring-shaped submerged planter material with water.

[0043] The PVC mold has an outer diameter of 5cm, an inner diameter of 2cm, and a ring block thickness of 2cm.

[0044] Example 3

[0045] A submerged plant planting material with oxygen slow-release function, the raw materials of which include 80 parts by weight of aggregate, 5 parts by weight of silicate cement, 10 parts by weight of fly ash, 15 parts by weight of calcium peroxide, and 45 parts by weight of water.

[0046] The aggregate is prepared by thoroughly mixing 1000 parts by weight of dehydrated bottom mud with a particle size ≤2mm and 50 parts by weight of water hyacinth powder with a particle size ≤0.125mm, pyrolyzing it in a muffle furnace at 500℃ in an oxygen-deficient environment for 2 hours, and then cooling it.

[0047] The specific steps of the above-mentioned method for preparing a submerged plant planting material with oxygen slow-release function are as follows:

[0048] After the aggregate, silicate cement, fly ash and calcium peroxide are thoroughly mixed, 40 parts by weight of deionized water are added and stirred evenly. The slurry is poured into a PVC mold, and mechanical vibration is used to remove the trapped air bubbles inside. After standard curing until the sample has initially set, it is demolded and air-dried naturally to obtain a ring-shaped submerged planter material with water.

[0049] The PVC mold has an outer diameter of 5cm, an inner diameter of 2cm, and a ring block thickness of 2cm.

[0050] Example 4

[0051] A submerged plant planting material with oxygen slow-release function, the raw materials of which include 80 parts by weight of aggregate, 15 parts by weight of slag silicate cement, 5 parts by weight of fly ash, 10 parts by weight of calcium peroxide, and 40 parts by weight of water.

[0052] The aggregate is prepared by thoroughly mixing 1000 parts by weight of dehydrated bottom mud with a particle size ≤2mm and 75 parts by weight of reed powder with a particle size ≤0.125mm, pyrolyzing it in a muffle furnace at 500℃ in an oxygen-deficient environment for 2 hours, and then cooling it.

[0053] The specific steps of the above-mentioned method for preparing a submerged plant planting material with oxygen slow-release function are as follows:

[0054] After the aggregate, silicate cement, fly ash and calcium peroxide are thoroughly mixed, 40 parts by weight of deionized water are added and stirred evenly. The slurry is poured into a PVC mold, and mechanical vibration is used to remove the trapped air bubbles inside. After standard curing until the sample has initially set, it is demolded and air-dried naturally to obtain a ring-shaped submerged planter with water-filled planting material 4.

[0055] The PVC mold has an outer diameter of 5cm, an inner diameter of 2cm, and a ring block thickness of 2cm.

[0056] Example 5

[0057] A submerged plant planting material with oxygen slow-release function, the raw materials of which include 75 parts by weight of aggregate, 10 parts by weight of silicate cement, 5 parts by weight of fly ash, 10 parts by weight of calcium peroxide, and 40 parts by weight of water.

[0058] The aggregate is prepared by thoroughly mixing 1000 parts by weight of dehydrated bottom mud with a particle size ≤2mm and 75 parts by weight of reed powder with a particle size ≤0.125mm, pyrolyzing it in a muffle furnace at 500℃ in an oxygen-deficient environment for 2 hours, and then cooling it.

[0059] The specific steps of the above-mentioned method for preparing a submerged plant planting material with oxygen slow-release function are as follows:

[0060] After the aggregate, silicate cement, fly ash and calcium peroxide are thoroughly mixed, 40 parts by weight of deionized water are added and stirred evenly. The slurry is poured into a PVC mold, and mechanical vibration is used to remove the trapped air bubbles inside. After standard curing until the sample has initially set, it is demolded and air-dried naturally to obtain a ring-shaped submerged planter material with water.

[0061] The PVC mold has an outer diameter of 5cm, an inner diameter of 2cm, and a ring block thickness of 2cm.

[0062] Comparative Example 1

[0063] A submerged plant planting material with slow oxygen release function, the raw materials of which include 100 parts by weight of dehydrated bottom mud and 40 parts by weight of water.

[0064] Collect dewatered sediment with a particle size ≤2mm.

[0065] The specific steps of the above-mentioned method for preparing a submerged plant planting material with oxygen slow-release function are as follows:

[0066] Add 40 parts by weight of deionized water to 100 parts by weight of dehydrated bottom mud and stir evenly. Pour the mud into a PVC mold, remove the trapped air bubbles by mechanical vibration, and cure according to standard until the sample initially sets. After demolding, let it air dry naturally to obtain ring-shaped submerged plant water-bearing material 6.

[0067] The PVC mold has an outer diameter of 5cm, an inner diameter of 2cm, and a ring block thickness of 2cm.

[0068] Comparative Example 2

[0069] A submerged plant planting material with slow oxygen release function, the raw materials of which include 105 parts by weight of aggregate, 15 parts by weight of fly ash and 50 parts by weight of water.

[0070] The aggregate is obtained by thoroughly mixing 1000 parts by weight of dehydrated bottom mud with a particle size ≤2mm and 75 parts by weight of reed powder with a particle size ≤0.125mm, pyrolyzing it in a muffle furnace at 500℃ in an oxygen-deficient environment for 2 hours, and then cooling it.

[0071] The outer diameter of the ring block mold is 5cm, the inner diameter is 2cm, and the thickness of the ring block is 2cm.

[0072] The specific steps of the above-mentioned method for preparing a submerged plant planting material with oxygen slow-release function are as follows:

[0073] After the aggregate and fly ash are thoroughly mixed, 40 parts by weight of deionized water are added and stirred evenly. The slurry is poured into a PVC mold, and mechanical vibration is used to remove the trapped air bubbles inside. After standard curing until the sample is initially set, it is demolded and then dried at 65°C to obtain ring-shaped submerged plant material with water.

[0074] The roots of the submerged plants are inserted into the ring-shaped submerged plant planting material prepared in Examples 1-5. Benthic animals of appropriate size are embedded in the ring to fix the submerged plants, thus creating submerged plant planting rings. The submerged plant planting rings are then placed into the target remediation water area at a planting density of 25 rings / m². 2 This will enable the effective restoration of submerged plant communities.

[0075] Submerged plants include Vallisneria natans, Potamogeton crispus, and Hydrilla verticillata, while benthic animals include Bellamya chinensis, whose size is slightly smaller than the inner diameter of the ring block. There are 1-3 Bellamya chinensis embedded in the ring block.

[0076] The submerged plant planting materials prepared in Example 1 and Comparative Examples 1-2 were immersed in deionized water, and the changes in dissolved oxygen concentration in the water were as follows: Figure 2 As shown. By Figure 2 It can be seen that the submerged plant material with water prepared in Example 1 has a certain oxygen slow release capacity and a long slow release time. During this period, the dissolved oxygen in the water is significantly higher than that in the submerged plant material with water prepared in Comparative Examples 1-2.

[0077] In summary, both cement and fly ash have a certain cementing effect. The addition of CaO2 can enhance the cementing effect, thereby preventing the ring-shaped submerged plant planting material from collapsing within a certain period of time, thus buying valuable time for the submerged plants to take root. At the same time, the biomass carbonaceous material in the planting ring can provide certain nutritional support for the roots during the rooting period of the submerged plants. On the other hand, oxidants such as calcium peroxide in the planting ring can slowly release oxygen, providing sufficient oxygen for the bottom sediment ecosystem during the rooting period of the submerged plants. This helps benthic animals to flocculate or directly ingest suspended particles in the bottom sediment caused by the planting ring, increases water transparency, and improves the survival rate of submerged plants.

[0078] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A submerged plant planting material with slow oxygen release function, characterized in that: The material is composed of aggregate, cementitious material, admixture, functional additive, and water. The mass ratio of the aggregate, cementitious material, admixture, functional additive, and water is (60-80):(5-15):(5-10):(5-15):(35-45). The aggregate is made by anoxic co-pyrolysis of biomass powder and dewatered bottom sediment. The mass ratio of biomass powder to dewatered bottom sediment is (5-10):

100. The biomass powder is one or a combination of two or more of the following: Vallisneria natans, Ceratophyllum demersum, Potamogeton crispus, Hydrilla verticillata, Phragmites communis, Thalia dealbata, Typha orientalis, Canna indica, Lythrum salicaria, Alpinia galbana, and Alternanthera philoxeroides. The particle size of the biomass powder is ≤0.125mm. The particle size of the dewatered sediment is ≤2.0mm. The cementitious material is general-purpose silicate cement, and the particle size of the cementitious material is ≤0.125mm; The admixture is one or a combination of two or more of the following: fly ash, granulated blast furnace slag powder, silica fume, and natural pozzolanic material, and the particle size of the admixture is ≤0.125mm. The functional additive is calcium peroxide.

2. The submerged plant planting material with oxygen slow-release function according to claim 1, characterized in that: The temperature for co-pyrolysis of the biomass powder and dehydrated sediment is 400-600℃.

3. The submerged plant planting material with oxygen slow-release function according to claim 1, characterized in that, The planting material is in the form of ring blocks.

4. A method for preparing a submerged plant planting material with oxygen slow-release function as described in any one of claims 1-3, characterized in that, The specific steps are as follows: S1. The water-containing bottom mud is subjected to dehydration, solidification, air drying, impurity removal and compaction in sequence to obtain dehydrated bottom mud; S2. Mix the washed and dried biomass powder with the dehydrated bottom mud in proportion, and carry out co-pyrolysis at a temperature of 400-600℃ under anaerobic conditions. After cooling, the aggregate is obtained. S3. Weigh out the aggregate, cementitious material, admixture, functional additive, and water in the specified mass amounts, mix them, place them in a mold, compact and shape them, cure them according to standard until initial setting, demold them, and then air dry them naturally to obtain a submerged plant material with water.

5. The method for preparing a submerged plant planting material with oxygen slow-release function according to claim 4, characterized in that, In step S1, the moisture content of the dewatered sediment is 15%-30%.

6. The method for preparing a submerged plant planting material with oxygen slow-release function according to claim 4, characterized in that, In step S2, the mixed biomass powder and dehydrated bottom mud are placed in a crucible, compacted, sealed, and then placed in a muffle furnace for co-pyrolysis for 1-3 hours.

Images