Sodium chlorite tablet for controlling growth of algae in water and preparation method thereof
By preparing sodium chlorite tablets, and using matrix materials and binders to form water-soluble tablets, the problem of controlling algae growth in water has been solved, achieving continuous inhibition of algae growth and reducing negative impacts on the aquatic environment.
Patent Information
- Application Number
- CN202510589362.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-05-09
- Filing Date
- 2025-05-08
- Publication Date
- 2025-11-11
AI Technical Summary
Existing technologies are insufficient to effectively control algae growth in water, and the direct addition of algaecides leads to rapid consumption and non-selective inhibition of aquatic organisms, making it impossible to achieve sustained inhibition of algae growth and avoid impacting the aquatic environment.
Develop a sodium chlorite tablet by mixing sodium chlorite and a binder in a matrix material to form a water-soluble tablet, controlling the release concentration of sodium chlorite between 0.5-20% by weight, using a binder of less than or equal to 5.0% by weight, and optionally using an activator or a co-sterilizer to improve the effect.
It achieves continuous inhibition of algae in water, reduces the consumption of algaecides, avoids excessive administration and unnecessary impact on the aquatic environment, and effectively controls algae growth.
Smart Images
Figure CN120918196A_ABST
Abstract
Description
[0001] Cross-references to related applications
[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 644,510, filed May 9, 2024. Technical Field
[0003] The disclosure of this patent application relates to controlling algae growth in water, and particularly to a water-soluble tablet for releasing sodium chlorite into water to control algae growth in water. Background Technology
[0004] Algal growth is a major problem in aquatic bodies due to the presence of nutrients that support its growth (especially phosphorus and nitrogen from surface runoff). Algal growth can lead to the production of toxins and disinfection byproducts (DBPs), such as trihalomethanes and haloacetic acids, which can have adverse health effects, particularly on the elderly, children, and pregnant women. Many methods exist for controlling algal growth, including implementing new policies, applying engineering solutions, and developing new scientific approaches. However, to date, these methods have achieved only limited success. For example, engineering strategies such as solar-powered circulation devices and underwater mixers consume significant amounts of energy and fail to address the odors and off-odors produced by algal decomposition. While both natural and synthetic algaecides have shown high efficiency and broad-spectrum algal-killing activity, adding these algaecides directly to water often results in rapid depletion and non-selective inhibition of all aquatic life.
[0005] To effectively use algaecides, a storage and administration mechanism must be developed to prevent rapid depletion. Sustained release or administration of the algaecide is necessary to provide sustained inhibition of algal growth and prevent overdose, while also avoiding unnecessary disinfection products and minimizing impact on the aquatic environment.
[0006] Therefore, there is a need for a sodium chlorite tablet for controlling algae growth in water and a method for preparing it to solve the above problems. Summary of the Invention
[0007] Sodium chlorite tablets contain sodium chlorite in a matrix material. The sodium chlorite tablets are water-soluble to release sodium chlorite, thereby controlling algae growth in the water. The concentration of sodium chlorite is between 0.5% by weight and 20% by weight of the sodium chlorite tablets. The sodium chlorite tablets also contain a binder with a concentration less than or equal to 5.0% by weight of the sodium chlorite tablets. As a non-limiting example, the matrix material may be sand. As another non-limiting example, the matrix material may be an inorganic powder, such as (but not limited to) silica powder, inorganic oxide powder, zeolite powder, porous inorganic oxide powder, or clay powder. Inorganic oxide powder may be (but not limited to) alumina powder, alumina-silica powder, titanium dioxide powder, or combinations thereof. The binder may be (but not limited to) polymer binders, clay binders, silica binders, bentonite, polyvinyl acetate, polyethyleneimine, or combinations thereof.
[0008] As another non-limiting example, the matrix material may be silanized cellulose. Non-limiting examples of silanized cellulose include silanized methyl cellulose, silanized carboxymethyl cellulose, silanized cotton, or combinations thereof. As another non-limiting example, the matrix material may be silica hydrogel.
[0009] Sodium chlorite tablets are prepared by mixing a matrix material with sodium chlorite to form a first mixture. A binder is mixed into the first mixture to form a second mixture. The second mixture is compressed to form sodium chlorite tablets, wherein the concentration of sodium chlorite is between 0.5% by weight and 20% by weight of the sodium chlorite tablets, and the concentration of the binder is less than or equal to 5.0% by weight of the sodium chlorite tablets. An activator may be added to the first mixture, such as (but not limited to) tartaric acid-impregnated activated carbon, tartaric acid powder, citric acid-impregnated activated carbon, or maleic acid-impregnated activated carbon. Alternatively, a co-sterilizer may be added to the first mixture, such as (but not limited to) polyhexamethylene biguanide, copper sulfate, or combinations thereof.
[0010] In another embodiment, sodium chlorite tablets are prepared by diluting colloidal silica sol in water, adding sodium chlorite to the diluted colloidal silica sol to form a mixture, placing the mixture in a tablet mold, and allowing the colloidal silica sol to transform into a gel.
[0011] The above and other features of this subject matter will become more apparent upon further reading of the following instructions. Attached Figure Description
[0012] Figure 1 A graph showing the release of sodium chlorite from a sodium chlorite tablet with a silica hydrogel matrix over time.
[0013] Figure 2A graph showing the change in algicidal activity of sodium chlorite tablets with a silica hydrogel matrix over time.
[0014] Figure 3A An optical microscope image of live Chlorella spp. taken from a control reservoir is shown on a counting plate.
[0015] Figure 3B An optical microscope image of dead Chlorella vulgaris taken from a test reservoir treated with sodium chlorite tablets having a silica hydrogel matrix is shown on a counting plate.
[0016] Figure 4A To show the respective samples taken from Figure 3A The control tank and Figure 3B A graph showing the average sodium chlorite concentration in water samples from the test reservoir on day 10.
[0017] Figure 4B To show the respective samples taken from Figure 3A The control tank and Figure 3B A graph showing the average algae concentration in water samples from the test reservoir on day 10.
[0018] Similar reference numerals are always used in the accompanying drawings to indicate the corresponding features. Detailed Implementation
[0019] Sodium chlorite tablets contain sodium chlorite in a matrix material. The sodium chlorite tablets are soluble in water to release sodium chlorite, thereby controlling algae growth in the water. The concentration of sodium chlorite is between 0.5% by weight and 20% by weight of the sodium chlorite tablets. The sodium chlorite tablets also contain a binder with a concentration less than or equal to 5.0% by weight of the sodium chlorite tablets. As a non-limiting example, the matrix material may be sand. As another non-limiting example, the matrix material may be an inorganic powder, such as (but not limited to) silica powder, inorganic oxide powder, zeolite powder, porous inorganic oxide powder, or clay powder. Inorganic oxide powder may be (but not limited to) alumina powder, alumina-silica powder, titanium dioxide powder, or combinations thereof. The binder may be (but not limited to) a polymer binder, clay binder, silica binder, bentonite, polyvinyl acetate, polyethyleneimine, or combinations thereof. The silica binder may be colloidal silica and may be used with an acid (e.g., nitric acid).
[0020] As another non-limiting example, the matrix material may be silanized cellulose. Non-limiting examples of silanized cellulose include silanized methyl cellulose, silanized carboxymethyl cellulose, silanized cotton, or combinations thereof. As another non-limiting example, the matrix material may be silica hydrogel. Silica hydrogel can be formed from colloidal silica sol via a sol-gel transformation. When the matrix material is silica hydrogel, it can also act as an adhesive.
[0021] Sodium chlorite tablets are prepared by mixing a matrix material with sodium chlorite to form a first mixture. A binder is mixed into the first mixture to form a second mixture. The second mixture is compressed to form sodium chlorite tablets, wherein the concentration of sodium chlorite is between 0.5% by weight and 20% by weight of the sodium chlorite tablets, and the concentration of the binder is less than or equal to 5.0% by weight of the sodium chlorite tablets. An activator may be added to the first mixture, such as (but not limited to) tartaric acid-impregnated activated carbon, tartaric acid powder, citric acid-impregnated activated carbon, or maleic acid-impregnated activated carbon. Alternatively, a co-sterilizer may be added to the first mixture, such as (but not limited to) polyhexamethylene biguanide, copper sulfate, or combinations thereof. The pressure applied during tableting is the same as that required for conventional tableting, generally in the range of 100-500 MPa. Activators, co-sterilizers or other additives may be added as needed, and their addition amounts may be lower than the sodium chlorite content in the tablets, for example, lower than 20% by weight, 15% by weight, 10% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight or lower.
[0022] In another embodiment, sodium chlorite tablets are prepared by diluting a colloidal silica sol in water, for example, to a concentration of 20% by weight or less. Sodium chlorite is added to the diluted colloidal silica sol to form a mixture, and the mixture is placed in a tablet mold, allowing the colloidal silica sol to transform into a gel.
[0023] Example 1
[0024] 1 g of sodium chlorite powder was mixed with 30 g of sand to form a homogeneous mixture. Then, 10 g of colloidal silica (AS-40, available from Sigma-Aldrich, 40% by weight) was added along with 2 mL of 0.14 M nitric acid as a binder. The mixture was compressed into tablets and allowed to dry. The finished tablets contained 3.0% by weight of sodium chlorite.
[0025] Example 2
[0026] 8.5g of sodium chlorite powder was mixed with 30g of sand to form a homogeneous mixture. Then, 10g of colloidal silica (AS-40) was added along with 2mL of 0.14M nitric acid as a binder. The mixture was compressed into tablets and allowed to dry. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0027] Example 3
[0028] 8.5g of sodium chlorite powder was mixed with 30g of sand to form a homogeneous mixture. 0.5g of tartaric acid-impregnated activated carbon was added to the mixture as an activator. Subsequently, 5g of colloidal silica (AS-40) was added along with 1mL of 0.14M nitric acid as a binder. The mixture was compressed into tablets and allowed to dry. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0029] Example 4
[0030] 8.5g of sodium chlorite powder was mixed with 32.8g of sand to form a homogeneous mixture. 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.2g of polyethyleneimine were added as binders, and the dry mixture was compressed into tablets at 100MPa to 500MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0031] Example 5
[0032] 8.5g of sodium chlorite powder was mixed with 32.6g of sand to form a homogeneous mixture. 0.2g of tartaric acid powder was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.2g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 400MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0033] Example 6
[0034] 8.5g of sodium chlorite powder was mixed with 32.6g of sand to form a homogeneous mixture. 0.2g of citric acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0035] Example 7
[0036] 8.5g of sodium chlorite powder was mixed with 32.6g of sand to form a homogeneous mixture. 0.2g of maleic acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 400MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0037] Example 8
[0038] 8.5g of sodium chlorite powder was mixed with 32.0g of sand to form a homogeneous mixture. 0.5g of tartaric acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0039] Example 9
[0040] 8.5g of sodium chlorite powder was mixed with 32.0g of sand to form a homogeneous mixture. 0.5g of maleic acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0041] Example 10
[0042] 1g of sodium chlorite powder was mixed with 30g of silica powder to form a homogeneous mixture. Then, 10g of colloidal silica (AS-40) was added along with 2mL of 0.14M nitric acid as a binder. The mixture was compressed into tablets and allowed to dry. The concentration of sodium chlorite in the finished tablets was 3.0% by weight.
[0043] Example 11
[0044] 8.5g of sodium chlorite powder was mixed with 30g of silica powder to form a homogeneous mixture. Then, 10g of colloidal silica (AS-40) was added along with 2mL of 0.14M nitric acid as a binder. The mixture was compressed into tablets and allowed to dry. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0045] Example 12
[0046] 8.5g of sodium chlorite powder was mixed with 30g of silica to form a homogeneous mixture. 0.5g of tartaric acid-impregnated activated carbon was added to the mixture as an activator. Subsequently, 5g of colloidal silica (AS-40) was added along with 1mL of 0.14M nitric acid as a binder. The mixture was compressed into tablets and allowed to dry. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0047] Example 13
[0048] 8.5g of sodium chlorite powder was mixed with 32.7g of silica to form a homogeneous mixture. 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.3g of polyethyleneimine were added as binders, and the dry mixture was compressed into tablets at 100MPa to 500MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0049] Example 14
[0050] 8.5g of sodium chlorite powder was mixed with 32.6g of silica to form a homogeneous mixture. 0.2g of tartaric acid powder was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.2g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 400MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0051] Example 15
[0052] 8.5g of sodium chlorite powder was mixed with 32.6g of silica to form a homogeneous mixture. 0.2g of citric acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 400MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0053] Example 16
[0054] 8.5g of sodium chlorite powder was mixed with 32.6g of silica to form a homogeneous mixture. 0.2g of maleic acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 400MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0055] Example 17
[0056] 8.5g of sodium chlorite powder was mixed with 32.0g of silica to form a homogeneous mixture. 0.5g of tartaric acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0057] Example 18
[0058] 8.5g of sodium chlorite powder was mixed with 30.0g of silica to form a homogeneous mixture. 0.5g of tartaric acid-impregnated activated carbon was added as an activator. 2.0g of polyhexamethylene biguanide was added as a co-sterilizer, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0059] Example 19
[0060] 8.5g of sodium chlorite powder was mixed with 30.3g of silica to form a homogeneous mixture. 0.2g of tartaric acid was added as an activator. 2.0g of polyhexamethylene biguanide and 0.2g of copper sulfate were added as co-sterilizers, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0061] Example 20
[0062] 4.25g of sodium chlorite and 4.25g of sodium hypochlorite powder were mixed with 30.3g of silica to form a homogeneous mixture. 0.2g of tartaric acid was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was then compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 10.0% by weight, and the concentration of sodium hypochlorite in the finished tablets was 10.0% by weight.
[0063] Example 21
[0064] 8.5g of sodium chlorite powder was mixed with 32.7g of alumina to form a homogeneous mixture. 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.3g of polyethyleneimine were added as binders, and the dry mixture was compressed into tablets at 100MPa to 500MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0065] Example 22
[0066] 8.5g of sodium chlorite powder was mixed with 32.7g of alumina to form a homogeneous mixture. 0.2g of maleic acid-impregnated activated carbon was added as an activator, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was compressed into tablets at 400MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0067] Example 23
[0068] 8.5g of sodium chlorite powder was mixed with 30.3g of a 1:1 mixture of alumina and silica to form a homogeneous mixture. 0.2g of tartaric acid was added as an activator. 2.0g of polyhexamethylene biguanide and 0.2g of copper sulfate were added as co-sterilizers, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was then compressed into tablets at 200MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0069] Example 24
[0070] 8.5g of sodium chlorite powder was mixed with 30.3g of 4A zeolite to form a homogeneous mixture. 0.2g of tartaric acid was added as an activator. 2.0g of polyhexamethylene biguanide and 0.2g of copper sulfate were added as co-sterilizers, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was then compressed into tablets at 300MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0071] Example 25
[0072] 8.5g of sodium chlorite powder was mixed with 30.5g of 13X zeolite to form a homogeneous mixture. 0.2g of tartaric acid was added as an activator. 2.0g of polyhexamethylene biguanide was added as a co-sterilizer, and 0.5g of bentonite, 0.5g of polyvinyl acetate, and 0.5g of polyethyleneimine were added as binders. The mixture was then compressed into tablets at 300MPa. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0073] Example 26
[0074] Dissolve 1.0 g of sodium chlorite in 15 mL of water and slowly add it to 9.0 g of dry silica powder until initially moistened. Dry the impregnated powder. Add 0.1 g of tartaric acid as an activator, and 0.5 g of bentonite, 0.5 g of polyvinyl acetate, and 0.5 g of polyethyleneimine as binders to the dried powder, then form the tablets by tableting, granulation, or extrusion. The concentration of sodium chlorite in the finished tablets is 10.0% by weight.
[0075] Example 27
[0076] Dissolve 1.0 g of sodium chlorite in 15 mL of water and slowly add it to 9.0 g of dry silica powder until initially moistened. Dry the impregnated powder. Add 0.1 g of tartaric acid as an activator, 2.0 g of polyhexamethylene biguanide and 0.2 g of copper sulfate as co-sterilizers, and 0.5 g of bentonite, 0.5 g of polyvinyl acetate and 0.5 g of polyethyleneimine as binders. Then form the tablets by tableting, granulation or extrusion. The concentration of sodium chlorite in the finished tablets is 10.0% by weight.
[0077] Example 28
[0078] Dissolve 1.0 g of sodium chlorite in 18 mL of water and slowly add it to 9.0 g of dry 4A zeolite until initially moistened. Dry the impregnated powder. Add 0.1 g of tartaric acid as an activator, and 0.5 g of bentonite, 0.5 g of polyvinyl acetate, and 0.5 g of polyethyleneimine as binders to the dried powder, then form the tablets by tableting, granulation, or extrusion. The concentration of sodium chlorite in the finished tablets is 10.0% by weight.
[0079] Example 29
[0080] Dissolve 1.0 g of sodium chlorite in 23 mL of water and slowly add it to 9.0 g of dry 13X zeolite until initially moistened. Dry the impregnated powder. Add 0.1 g of tartaric acid as an activator, 2.0 g of polyhexamethylene biguanide and 0.2 g of copper sulfate as co-sterilizers, and 0.5 g of bentonite, 0.5 g of polyvinyl acetate and 0.5 g of polyethyleneimine as binders. Then form the tablets by tableting, granulation or extrusion. The concentration of sodium chlorite in the finished tablets is 10.0% by weight.
[0081] Example 30
[0082] Dissolve 1.0 g of sodium chlorite in 11 mL of water and slowly add it to 9.0 g of montmorillonite until initially moistened. Dry the impregnated powder. Add 0.1 g of tartaric acid as an activator, 2.0 g of polyhexamethylene biguanide and 0.2 g of copper sulfate as co-sterilizers, and 0.5 g of bentonite, 0.5 g of polyvinyl acetate and 0.5 g of polyethyleneimine as binders, then form the tablets by extrusion. The concentration of sodium chlorite in the finished tablets is 10.0% by weight.
[0083] Example 31
[0084] 2.0 g of sodium chlorite was mixed with 7.0 g of silanized cellulose. Then, 0.2 g of tartaric acid was added as an activator, and 0.5 g of polyvinyl acetate and 0.3 g of polyethyleneimine were added as binders. The mixture was then compacted into a container with an opening for water diffusion and release of the activated sodium chlorite. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0085] Example 32
[0086] 2.0 g of sodium chlorite was mixed with 5.0 g of silanized cotton. 0.2 g of tartaric acid was added to the mixture as an activator, 2.0 g of polyhexamethylene biguanide and 0.2 g of copper sulfate were added as co-sterilizers, and 0.5 g of polyvinyl acetate and 0.5 g of polyethyleneimine were added as binders. The mixture was then compacted into a container with an opening for water diffusion and release of the activated sodium chlorite. The concentration of sodium chlorite in the finished tablets was 20.0% by weight.
[0087] Example 33
[0088] In an ice bath, 400 g of tetraethyl orthosilicate was vigorously mixed with 120 g of 0.14 M nitric acid. When cooled to near room temperature, 20 g of sodium chlorite was added under vigorous mixing. Subsequently, 200 g of 40% Ludox AS-40 colloidal silica sol (available from Sigma-Aldrich) was added dropwise. The concentration of sodium chlorite in the finished tablets was 1.6% by weight.
[0089] Example 34
[0090] In an ice bath, 400g of tetraethyl orthosilicate was vigorously mixed with 120g of 0.14M nitric acid. When cooled to near room temperature, 5g of sodium chlorite was added under vigorous mixing. 20g of polyhexamethylene biguanide was added as a co-sterilizer. Subsequently, 200g of 40% Ludox AS-40 colloidal silica sol was added dropwise to form a hydrogel. The concentration of sodium chlorite in the finished tablets was 0.4% by weight.
[0091] Example 35
[0092] In an ice bath, 200g of tetraethyl orthosilicate was vigorously mixed with 120g of 0.14M nitric acid. When cooled to near room temperature, 5g of sodium chlorite and 200g of water were added under vigorous mixing. 20g of polyhexamethylene biguanide was added as a co-sterilizer. Subsequently, 200g of 40% Ludox AS-40 colloidal silica sol was added dropwise to form a hydrogel. The concentration of sodium chlorite in the finished tablets was 0.4% by weight.
[0093] Example 36
[0094] In an ice bath, 400g of tetraethyl orthosilicate was vigorously mixed with 120g of 0.14M nitric acid. When cooled to near room temperature, 20g of sodium chlorite was added under vigorous mixing. 20g of polyhexamethylene biguanide and 2g of copper sulfate were added as co-sterilizers. Subsequently, 200g of 40% Ludox AS-40 colloidal silica sol was added dropwise to form a hydrogel. The concentration of sodium chlorite in the finished tablets was 1.6% by weight.
[0095] Example 37
[0096] To test the effectiveness of sodium chlorite administration, 20 g of a silica hydrogel matrix containing 1.6 wt% sodium chlorite, prepared according to Example 36, was immersed in 2 L of water. Water samples were taken every 24 hours for 20 days, and the water was changed accordingly. Figure 1 The figure shows the representative concentration of sodium chlorite from the time of administration.
[0097] Example 38
[0098] To study the algicidal activity, 100 ml of sodium chlorite administration water sample taken from Example 37 was mixed with 100 ml of water containing a live autotrophic Chlorella culture (10 ml). 8 Mix 100 ml of Chlorella microphylla (1 small algae) and 10 min. Quantify the live and dead algae after staining and microscopic observation. Figure 2 The algae-killing activity was plotted over 20 days.
[0099] Example 39
[0100] Field tests were conducted in two water storage tanks. The larger water storage tank (1800m³) 3 The smaller water storage tank (1500m³) was used as the testing site. 3 As a control, 1g of the sample from Example 37 was used per cubic meter of water, and the observation period was 10 days. Figure 3A and 3B As shown, the live Chlorella was quantitatively analyzed by periodically collecting water samples and observing them under a microscope.
[0101] like Figure 4A and 4B As shown, during the 10-day observation period, the average sodium chlorite concentrations in the control and test water tanks were 0.01 ppm and 0.46 ppm, respectively, with corresponding algal concentrations of 7 x 10⁻⁶ ppm. 5 and 5 x 10 per liter 4 Compared to the control tank, sodium chlorite tablets reduced algae growth by 92.8% in the test tank.
[0102] It should be understood that sodium chlorite tablets for controlling algae growth in water and methods for preparing the same are not limited to the specific embodiments described above, but rather cover any and all embodiments within the scope of the superior expression of the claims supported by the embodiments described herein, or shown in the drawings or above in a manner sufficient to enable those skilled in the art to implement and use the claimed subject matter.
Claims
1. A sodium chlorite tablet comprising: Matrix material; Sodium chlorite, with a concentration between 0.5% by weight and 20% by weight of the sodium chlorite tablets; and The binder has a concentration less than or equal to 5.0% by weight of the sodium chlorite tablets.
2. The sodium chlorite tablet according to claim 1, wherein the matrix material comprises sand.
3. The sodium chlorite tablet according to claim 1, wherein the binder is selected from the group consisting of: polymer binders, clay binders, silica binders, bentonite, polyvinyl acetate, polyethyleneimine, and combinations thereof.
4. The sodium chlorite tablet according to claim 1, wherein the matrix material comprises inorganic powder.
5. The sodium chlorite tablet according to claim 4, wherein the inorganic powder is selected from the group consisting of: silica powder, inorganic oxide powder, zeolite powder, porous inorganic oxide powder, and clay powder.
6. The sodium chlorite tablet according to claim 5, wherein the inorganic oxide powder is selected from the group consisting of: alumina powder, alumina-silica powder, titanium dioxide powder, and combinations thereof.
7. The sodium chlorite tablet according to claim 5, wherein the porous inorganic oxide powder is selected from the group consisting of: porous silica powder, porous alumina powder, porous alumina-silica powder, and combinations thereof.
8. The sodium chlorite tablet according to claim 1, wherein the matrix material comprises silanized cellulose.
9. The sodium chlorite tablet according to claim 8, wherein the silanized cellulose is selected from the group consisting of: silanized methyl cellulose, silanized carboxymethyl cellulose, silanized cotton, and combinations thereof.
10. The sodium chlorite tablet according to claim 1, wherein the matrix material comprises silica hydrogel.
11. A method for preparing sodium chlorite tablets, comprising: The matrix material is mixed with sodium chlorite to form a first mixture; The adhesive is mixed with the first mixture to form a second mixture; as well as The second mixture is compressed into tablets to form sodium chlorite tablets. The concentration of sodium chlorite is between 0.5% by weight and 20% by weight of the sodium chlorite tablets, and The concentration of the binder is less than or equal to 5.0% by weight of the sodium chlorite tablet.
12. The method for preparing sodium chlorite tablets according to claim 11, further comprising adding an activator to the first mixture.
13. The method for preparing sodium chlorite tablets according to claim 12, wherein the activator is selected from the group consisting of: tartaric acid-impregnated activated carbon, tartaric acid powder, citric acid-impregnated activated carbon, and maleic acid-impregnated activated carbon.
14. The method for preparing sodium chlorite tablets according to claim 11, wherein the matrix material comprises sand.
15. The method for preparing sodium chlorite tablets according to claim 11, wherein the binder is selected from the group consisting of: polymer binders, clay binders, silica binders, nitric acid, bentonite, polyvinyl acetate, polyethyleneimine, and combinations thereof.
16. The method for preparing sodium chlorite tablets according to claim 11, wherein the matrix material comprises inorganic powder.
17. The method for preparing sodium chlorite tablets according to claim 16, wherein the inorganic powder is selected from the group consisting of: silica powder, inorganic oxide powder, zeolite powder, porous inorganic oxide powder, and clay powder.
18. The method for preparing sodium chlorite tablets according to claim 17, wherein the inorganic oxide powder is selected from the group consisting of: alumina powder, alumina-silica powder, titanium dioxide powder, and combinations thereof.
19. The method for preparing sodium chlorite tablets according to claim 17, wherein the porous inorganic oxide powder is selected from the group consisting of: porous silica powder, porous alumina powder, porous alumina-silica powder, and combinations thereof.
20. The method for preparing sodium chlorite tablets according to claim 11, wherein the matrix material comprises silanized cellulose.
21. The method for preparing sodium chlorite tablets according to claim 20, wherein the silanized cellulose is selected from the group consisting of: silanized methyl cellulose, silanized carboxymethyl cellulose, silanized cotton, and combinations thereof.
22. The method for preparing sodium chlorite tablets according to claim 12, further comprising adding a co-disinfectant to the first mixture.
23. The method for preparing sodium chlorite tablets according to claim 22, wherein the co-disinfectant is selected from the group consisting of: polyhexamethylene biguanide, copper sulfate, and combinations thereof.
24. A method for preparing sodium chlorite tablets, comprising: Dilute the colloidal silica sol in water; Sodium chlorite was added to the diluted colloidal silica sol to form a mixture; as well as The mixture is placed in a tablet mold, and the colloidal silica sol is converted into a gel.
25. The method for preparing sodium chlorite tablets according to claim 24, further comprising adding a co-sterilizer to the mixture.
26. The method for preparing sodium chlorite tablets according to claim 25, wherein the co-disinfectant is selected from the group consisting of: polyhexamethylene biguanide, copper sulfate, and combinations thereof.