Sustained-release sodium silicate particles, preparation method thereof and application of sustained-release sodium silicate particles in growth of benthic algae

Abstract

The invention discloses slow-release sodium silicate particles, a preparation method thereof and application of the slow-release sodium silicate particles in growth of benthic algae. The particles comprise sodium silicate, bentonite, clay and calcium carbonate. The slow-release sodium silicate particles prepared by the invention can stably and slowly release silicic acid in a water body, prolong the supply time of a silicon source, improve the competitiveness of diatom, promote the water body to succession towards a diatom-dominated algae structure direction, improve the ecological environment at the bottom of the water body and improve the transparency of the water body; the method has a wide application prospect in freshwater lake and wetland restoration and eutrophication treatment; the slow-release sodium silicate particles prepared by the invention can reduce the dissolution rate of sodium silicate, reduce waste, reduce instantaneous impact on water, and are green and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of ecological restoration and water environment management, and in particular to slow-release sodium silicate particles, a preparation method thereof, and application thereof in the growth of benthic algae. Background Art

[0002] Benthic diatoms play an important role in aquatic ecosystems. They are important food for many aquatic organisms and are also an important component of primary productivity in water bodies. However, due to insufficient silicon content in water bodies, the growth of benthic diatoms is limited, which further exacerbates the competitive advantage of harmful algae such as cyanobacteria, leading to ecological imbalance and decreased transparency in water bodies.

[0003] Chinese patent CN110980955B discloses a method for managing the ecosystem of eutrophic water bodies, which mainly solves the problems of water ecological imbalance and decreased transparency caused by excessive growth of cyanobacteria due to eutrophication of water bodies by removing fish, adding silicate composite aqueous solution, planting emergent plants and constructing submerged plant communities.

[0004] However, in the process of implementing the technical solution created by the present invention, the applicant found that the existing treatment method not only has complicated procedures, but also causes large instantaneous changes in the water environment after the addition of the silicate composite aqueous solution, and has poor sustainability, and does not fundamentally solve the problems of excessive growth of harmful algae, ecological imbalance of water bodies and decreased transparency. Summary of the invention

[0005] The present invention can solve the above problems existing in the prior art by providing a slow-release sodium silicate particle and a preparation method thereof and application thereof in the growth of benthic algae.

[0006] In order to solve the above technical problems, the present invention provides a slow-release sodium silicate particle, comprising the following components in percentage by weight:

[0007] Sodium silicate 20-35%, bentonite 45-55%, clay 10-15%, calcium carbonate 5-15%.

[0008] In a preferred embodiment of the present invention, the components are included in the following weight percentages: 30% sodium silicate, 50% bentonite, 15% clay, and 5% calcium carbonate.

[0009] In a preferred embodiment of the present invention, the particle size of the slow-release sodium silicate particles is 4 to 5 mm.

[0010] In a preferred embodiment of the present invention, the dissolution period of the slow-release sodium silicate particles in water is 3 to 5 months.

[0011] In order to solve the above technical problems, the present invention also provides a method for preparing slow-release sodium silicate particles, comprising the following steps:

[0012] (1) Material mixing: mixing the sodium silicate, bentonite, clay and calcium carbonate according to a weight ratio, adding an appropriate amount of clean water and stirring evenly to form a muddy mixture;

[0013] (2) Granulation: The obtained muddy mixture is kneaded into wet granules with a diameter of 4 to 5 mm using a granulation device;

[0014] (3) Drying and molding: The wet particles are sintered at low temperature to obtain the slow-release sodium silicate particles.

[0015] In a preferred embodiment of the present invention, the process conditions of the low-temperature sintering are 50-80° C. and 12-24 hours.

[0016] In order to solve the above technical problems, the present invention also provides an application of slow-release sodium silicate particles in the growth of benthic algae. The slow-release sodium silicate particles are evenly added to the target water body, slowly dissolved and gradually release silicic acid, thereby promoting the continuous growth of benthic algae.

[0017] In a preferred embodiment of the present invention, the amount of the slow-release sodium silicate particles is 5 to 20 g / m 2 .

[0018] In a preferred embodiment of the present invention, the slow-release sodium silicate particles are added in an amount such that the silicate concentration in the water body is 5 to 10 mg / L.

[0019] The invention has the following beneficial effects: the slow-release sodium silicate particles prepared by the invention can stably and slowly release silicic acid in water, prolong the supply time of silicon source, improve the competitiveness of diatoms, promote the ecological balance of water bodies, improve the ecological environment at the bottom of water bodies, and improve the transparency of water bodies, and have broad application prospects in the restoration of freshwater lakes and wetlands and the control of eutrophication; the slow-release sodium silicate particles prepared by the invention can reduce the dissolution rate of sodium silicate, reduce waste, reduce the instantaneous impact on water bodies, and are green and environmentally friendly. DETAILED DESCRIPTION

[0020] The following is a detailed description of the preferred embodiments of the present invention so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0021] The invention discloses a slow-release sodium silicate particle, wherein the particle size of the slow-release sodium silicate particle is 4 to 5 mm, and the dissolution period in the water body is 3 to 5 months. Through long-term dissolution, silicic acid is slowly released, which, on the one hand, will not cause a huge instantaneous impact on the water environment due to a sudden increase in the amount of silicic acid, and on the other hand, provides a long-term and stable silicon source supply to benthic algae, ensuring that the benthic algae can effectively resume growth, form a benthic algae community, effectively fight against cyanobacteria, fundamentally solve the problem of ecological imbalance in the water body, and improve the transparency of the water body.

[0022] Specifically, a slow-release sodium silicate granule comprises the following components in percentage by weight:

[0023] Sodium silicate 20-35%, the sodium silicate is the core material of the slow-release particles and is used to provide silicic acid.

[0024] 45-55% bentonite and 10-15% clay. The bentonite and clay are matrix materials used to control the dissolution rate of the slow-release sodium silicate particles and enhance the particle strength.

[0025] Calcium carbonate 5-15%, the calcium carbonate is a regulator for adjusting particle density and dissolution performance.

[0026] The method for preparing the above-mentioned slow-release sodium silicate particles comprises the following steps:

[0027] (1) Material mixing: The sodium silicate, bentonite, clay and calcium carbonate are mixed according to weight ratio, and an appropriate amount of clean water is added and stirred evenly to form a muddy mixture.

[0028] (2) Granulation: The obtained muddy mixture is kneaded into wet granules with a diameter of 4 to 5 mm using a granulation device;

[0029] (3) Drying and molding: The wet particles are sintered at a low temperature of 50 to 80° C. for 12 to 24 hours to obtain the slow-release sodium silicate particles.

[0030] Example 1

[0031] Calculated by weight percentage, 30wt% of sodium silicate, 50wt% of bentonite, 15wt% of clay and 5wt% of calcium carbonate accounting for the total material amount are weighed and mixed, and an appropriate amount of clean water is added and stirred evenly to form a muddy mixture, which is kneaded into wet particles with a diameter of 4 to 5mm using a granulating equipment, and finally sintered in a drying oven at 55°C for 24h to obtain the slow-release sodium silicate particles.

[0032] The slow-release sodium silicate particles prepared by the above method were applied to an experiment to promote the growth of benthic algae in freshwater lakes.

[0033] Specifically, in a freshwater lake with an area of ​​10 hectares and an average water depth of 2 meters, 2 tons of slow-release particles were evenly dropped into the lake in accordance with the standard of controlling the silicate concentration in the water area at 5 mg / L.

[0034] Water samples were collected every two weeks to monitor the silica concentration in the water and the density of benthic diatoms.

[0035] After 3 months, the density of diatoms increased by 50%, the density of cyanobacteria decreased by 40%, and the water transparency increased from the original 0.5 meters to 1.2 meters.

[0036] Example 2

[0037] The slow-release sodium silicate particles prepared in Example 1 were applied to wetland ecological restoration experiments.

[0038] Specifically, in a wetland system with an area of ​​5 hectares, at 1kg / m 2 The slow-release sodium silicate particles are evenly applied according to the standard. The slow-release sodium silicate particles gradually release silicic acid within 5 months, promoting the joint recovery of benthic diatoms and submerged plants.

[0039] Three months later, ecological monitoring results showed that the wetland plant coverage rate increased by 30% and the water quality improved significantly.

[0040] Comparative Example 1

[0041] Compared with Example 1, the same amount of sodium silicate was added to similar water bodies at one time so that the total amount of silicic acid added to the water bodies was the same. After 3 months, the density of diatoms was increased by 10%, the density of cyanobacteria decreased by 5%, and the transparency of the water bodies did not change significantly.

[0042] Comparative Example 2

[0043] Compared with Example 2, the same amount of sodium silicate was added to a similar wetland at one time, so that the total amount of silicate added to the water body was the same. After 3 months, the plant coverage rate of the detected wetland increased by 5%, and the water quality improvement was not obvious.

[0044] The slow-release sodium silicate particles of the present invention have the following advantages:

[0045] 1. Promote the growth of benthic diatoms: The slow-release particles continuously release silicic acid, providing the silicon source required for the growth of benthic diatoms, increasing the density of benthic diatoms, and improving the ecological environment at the bottom of the water body.

[0046] 2. Inhibit harmful algae: enhance the competitive advantage of diatoms in algae communities and inhibit the reproduction of harmful algae such as cyanobacteria.

[0047] 3. Improve water transparency: The increase of benthic diatoms and the decrease of cyanobacteria improve the transparency of water bodies, improve the lighting conditions of water bodies, and contribute to the recovery of submerged vegetation.

[0048] 4. Slow-release and environmentally friendly: The slow-release design avoids the rapid dissolution and waste of sodium silicate, reduces the instantaneous impact on the water body, and is green and environmentally friendly.

[0049] The present invention provides an innovative slow-release sodium silicate particle technology, which can provide a long-term and stable silicon source for the growth of benthic diatoms, and has broad application prospects in the restoration of freshwater lakes and wetlands and the treatment of eutrophic water bodies.

[0050] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A sustained-release sodium silicate granule, characterized in that: The composition comprises the following weight percentages: Sodium silicate 20-35%, bentonite 45-55%, clay 10-15%, calcium carbonate 5-15%.

2. The sustained-release sodium silicate particles according to claim 1, characterized in that The composition comprises the following weight percentages: Sodium silicate 30%, bentonite 50%, clay 15%, calcium carbonate 5%.

3. The sustained-release sodium silicate particles according to claim 2, characterized in that: The particle size of the slow-release sodium silicate particles is 4 to 5 mm.

4. The sustained-release sodium silicate particles according to claim 3, characterized in that: The dissolution period of the slow-release sodium silicate particles in water is 3 to 5 months.

5. A method for preparing the sustained-release sodium silicate particles according to any one of claims 1 to 4, characterized in that: The steps include: (1) Material mixing: mixing the sodium silicate, bentonite, clay and calcium carbonate according to a weight ratio, adding an appropriate amount of clean water and stirring evenly to form a muddy mixture; (2) Granulation: The obtained muddy mixture is kneaded into wet granules with a diameter of 4 to 5 mm using a granulation device; (3) Drying and molding: The wet particles are sintered at low temperature to obtain the slow-release sodium silicate particles.

6. The method for preparing the sustained-release sodium silicate particles according to claim 5, characterized in that The process conditions of the low temperature sintering are 50-80° C. and 12-24 hours.

7. Use of the slow-release sodium silicate granules according to any one of claims 1 to 4 in the growth of benthic algae, characterized in that: The slow-release sodium silicate particles are evenly placed into the target water body, slowly dissolved and gradually release silicate, thereby promoting the continuous growth of benthic algae.

8. The use of the slow-release sodium silicate particles in the growth of benthic algae according to claim 7, characterized in that: The amount of the slow-release sodium silicate particles is 5 to 20 g / m 2 .

9. The use of the slow-release sodium silicate particles in the growth of benthic algae according to claim 8, characterized in that: The slow-release sodium silicate particles are added in an amount such that the silicate concentration in the water body is 5 to 10 mg / L.