Comprehensive water quality improvement algae inhibitor and its preparation method and application

Abstract

The application discloses a kind of comprehensive water quality promotion algae inhibitor and its preparation method and application, belong to water quality management field.The comprehensive water quality promotion algae inhibitor is according to mass percentage component: lanthanum iron modified bentonite 15-35%, modified sodium percarbonate 30-45%, polyaluminum chloride 8-15%, binder 20-30%;The mass ratio of lanthanum iron modified bentonite and modified sodium percarbonate is 1-3:1;The binder is composed of natural porous mineral and cement.The comprehensive water quality promotion algae inhibitor disclosed in the application can inhibit algae, eliminate algal toxins, oxidize ammonia nitrogen, increase oxygen and activate water environment ecology on the one hand, and the modified lanthanum component can more stably remove phosphorus on the other hand, and can reduce the pH increase caused by the use of sodium percarbonate, and can promote water quality under the coupling of other adsorption materials, adsorb pollutants, and fundamentally solve the problem of water eutrophication.

Description

Technical Field

[0001] This invention relates to the field of river and lake water environment, specifically to a comprehensive water quality improvement and algae-inhibiting agent, its preparation method, and its application. Background Technology

[0002] In recent years, river and lake management has achieved initial results, generally eliminating Class V or worse water quality. However, cyanobacteria blooms in lakes remain frequent, widespread, and prone to outbreaks. Compared to rivers, lakes have a certain degree of fluidity, making them more susceptible to cyanobacteria blooms. The spring recovery process is mainly controlled by the temperature and dissolved oxygen of the lake's sediment surface. The substances and energy required for photosynthesis and cell division determine the growth of algal blooms in spring and summer. Given suitable temperature and hydrological conditions, large amounts of cyanobacteria that have accumulated in the water will rise to the surface and accumulate, forming visible algal blooms. Eutrophication promotes cyanobacteria blooms. After blooming, the algae cover the water surface, blocking sunlight and preventing underwater plants from photosynthesizing. This gradually reduces dissolved oxygen in the water, further exacerbating water quality deterioration.

[0003] Currently, lanthanides are a hot research topic in phosphorus-locking agents, with lanthanum carbonate being a mainstream material. However, it still has some shortcomings in practical applications: firstly, lanthanum is too expensive; secondly, it suffers from phosphorus adsorption saturation and low efficiency. Regarding algae suppression, the principle of chemical dosing is basically based on strong oxidants, but these all have a certain degree of toxicity, making dosage difficult to control. Sodium percarbonate (SPC), while also possessing strong oxidizing properties, is more suitable for pond aeration and disinfection due to its easy decomposition, and its effect on algae suppression is not significant. Excessive dosage can also cause a sharp rise in pH. Furthermore, the above methods essentially treat eutrophication and cyanobacterial blooms separately, but in reality, algae and eutrophication can mutually deteriorate the aquatic ecosystem. For example, after algae removal, excessive nitrogen and phosphorus remain in the water system, and the aquatic ecosystem structure remains weakened, leading to recurrence after a period of time. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a comprehensive water quality improvement and algae-inhibiting agent that is readily available, environmentally friendly, and removes eutrophic substances while eliminating algae, and a method for preparing the same, in order to solve the above problems.

[0005] The technical solution adopted in this invention is:

[0006] A comprehensive water quality improvement and algae-inhibiting agent is prepared by processing and mixing lanthanum-iron modified bentonite, modified sodium percarbonate, and binder.

[0007] Specifically, the comprehensive water quality improvement and algae-inhibiting agent comprises the following components by mass percentage: 15%-40% lanthanum-iron modified bentonite, 30%-55% modified sodium percarbonate, and 20%-40% binder; the mass ratio of lanthanum-iron modified bentonite to modified sodium percarbonate is 1-3:1; the binder is composed of natural porous minerals and cement, and the mass ratio of natural porous minerals to cement is 1-2:1.

[0008] Furthermore, the comprehensive water quality improvement and algae-inhibiting agent may also include polyaluminum chloride, the comprehensive water quality improvement and algae-inhibiting agent having the following composition by mass percentage: 15%-35% lanthanum iron modified bentonite, 30%-45% modified sodium percarbonate, 8%-15% polyaluminum chloride, and 20%-30% binder; the mass ratio of the lanthanum iron modified bentonite to the modified sodium percarbonate is 1-3:1; the binder is composed of natural porous minerals and cement, the mass ratio of the natural porous minerals to the cement is 1-2:1.

[0009] The lanthanum-iron modified bentonite used in this invention is prepared by the following method:

[0010] (1) Mix calcium-based bentonite, straw biochar powder and distilled water in proportion, dry and crush to obtain mixed powder; calcine the mixed powder at 300℃-500℃ to obtain biochar modified bentonite.

[0011] The mass ratio of calcium-based bentonite, straw biochar powder, and distilled water is 3:2:5; the calcination heating rate is 10-15℃ / min, and the calcination time is 1-3h.

[0012] (2) LaCl3·7H2O, Fe(NO3)3·9H2O and biochar-modified bentonite were stirred in distilled water and reacted. Na2CO3 solution was added dropwise until pH=8. Stirring was continued to ensure complete reaction. After the reaction was completed, the mixture was filtered, washed and dried to obtain lanthanum-iron modified bentonite.

[0013] The mass ratio of LaCl3·7H2O, Fe(NO3)3·9H2O, and biochar-modified bentonite is 0.3:0.1:1; the molar concentration of the Na2CO3 solution is 1 mol / L; the reaction temperature is 45-50℃; and the drying process involves placing the solid in a 35℃ oven for 12 h.

[0014] The modified sodium percarbonate used in this invention is silicate-coated sodium percarbonate particles, and its preparation method is as follows: SPC is placed in a stirrer, and a sodium silicate solution with a mass concentration of 40% is added dropwise at a stirring speed of 300r / min. The mass ratio of sodium percarbonate particles to sodium silicate solution is 10:4-5, and then the mixture is dried in a fluidized bed.

[0015] The natural porous minerals used in this invention are selected from any one or more of zeolite, kaolin, attapulgite, bentonite and vermiculite powder. Utilizing their porosity and adhesiveness, they can be used as adhesives and also give the comprehensive water quality improvement algae inhibitor good adsorption performance.

[0016] The cement used in this invention is selected from silicate cement and aluminate cement.

[0017] The present invention further provides a method for preparing the above-mentioned comprehensive water quality improvement and algae inhibitor, wherein the above-mentioned raw materials are mixed evenly and fed into an extrusion granulator to be pressed into granules, the particle size is controlled at 1~20 mm, and the finished granules are obtained.

[0018] The present invention further provides a method for applying the above-mentioned comprehensive water quality improvement and algae-inhibiting agent: the above-mentioned comprehensive water quality improvement and algae-inhibiting agent particles are evenly sprayed into the river water to improve the overall water quality and have the effect of removing and inhibiting algae.

[0019] Furthermore, the dosage of the comprehensive water quality improvement and algae-inhibiting agent in the water body is 0.1~1 kg / m³. 3 .

[0020] The beneficial effects of this invention are mainly reflected in:

[0021] (1) Lanthanum-iron carbonate modified bentonite utilizes straw biochar powder to reduce the loading difficulty of lanthanide substances on natural mineral adsorbents, iron reduces its usage cost, and natural porous mineral adsorbents serve as carriers to stabilize the structure on the one hand, and their porous structure enhances their adsorption performance on the other hand, thus jointly strengthening the use effect of lanthanum-iron carbonate modified bentonite.

[0022] (2) After being strengthened and stabilized, sodium percarbonate has reduced its disadvantage of being easily decomposed. Under the action of lanthanum carbonate, the problem of pH increase caused by the use of sodium percarbonate in water has been solved.

[0023] (3) According to actual needs, adding aluminum chloride can increase phosphorus absorption on the one hand, and enhance flocculation and sedimentation performance on the other hand, allowing the microcapsules after strong oxidation and destruction of sodium percarbonate to settle, thereby improving the transparency of the water body.

[0024] (4) This invention utilizes a single agent. Only a small amount needs to be added to simultaneously solve the ecological problems of algal blooms and eutrophication. Attached Figure Description

[0025] Figure 1 Comparison of phosphorus removal effects of lanthanum-iron modified bentonite prepared in Example 1;

[0026] Figure 2 These are photos of the application of the comprehensive water quality improvement algae inhibitor in Example 4.

[0027] Figure 3 Example 4 shows the change curves of water biochemical indicators after the application of the comprehensive water quality improvement algaecide.

[0028] Figure 4 Example 4 shows the pH and dissolved oxygen change curves of the water body after the application of the comprehensive water quality improvement algaecide.

[0029] Figure 5 These are photos of the application of the comprehensive water quality improvement and algae-inhibiting agent in Example 5.

[0030] Figure 6 The curves showing the changes in biochemical indicators of the water body after the application of the comprehensive water quality improvement and algae-inhibiting agent in Example 5 are shown. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto. Example 1

[0032] Preparation of lanthanum-iron modified bentonite:

[0033] Calcium-based bentonite (AT-798) from Lingshou County Aotai Mineral Products, corn and wheat straw biochar powder (HSSWT006) from Henan Housen Environmental Protection, and distilled water were mixed in a mass ratio of 3:2:5 and stirred for 4 hours. The mixture was then dried in a 100℃ oven for 12 hours, crushed, ground, and calcined in a muffle furnace at a heating rate of 10℃ / min to 300℃, 400℃, and 500℃, respectively, for 2 hours. This yielded biochar-modified bentonite, labeled as CB. 300 CB 400 CB 500 .

[0034] With no biochar powder added as a control, modified bentonite B was prepared by calcining calcium-based bentonite and distilled water in a mass ratio of 3:3 at a heating rate of 10℃ / min to 300℃ for 2 hours. 300 .

[0035] Dissolve 1.8 g LaCl3·7H2O, 0.6 g Fe(NO3)3·9H2O, and 6 g of the modified bentonite in 450 ml of distilled water. Stir at 45 °C for 2 h. Slowly add 1 mol / L Na2CO3 dropwise until the pH reaches 8, and continue stirring for 2 h. Filter, and repeatedly wash the solid with deionized water until the pH is neutral and 0.05 mol / L Ag is used. + Cl was not detected in the supernatant - Finally, the solid was dried in an oven at 35°C for 12 h. The resulting solid was then ground to prepare lanthanum-iron modified bentonite, which was labeled as LaFe-CB. 300 LaFe-CB 400 LaFe-CB500 and LaFe-B 300 .

[0036] The prepared spherical lanthanum-iron modified bentonite was subjected to adsorption experiments: with an initial phosphate concentration of 20 mg / L, the dosage was 10 g / L, the adsorption oscillation speed was 150 r / min, and the adsorption time was 5 h at room temperature. After adsorption, the mixture was filtered, and the phosphate concentration in the supernatant was determined using the molybdenum blue spectrophotometric method. The experimental results are as follows: Figure 1 As shown, the results indicate that co-pyrolysis of straw biochar and bentonite is beneficial to improving the phosphate removal rate of lanthanum-iron modified bentonite. Furthermore, the phosphate removal rate further increases with temperature up to 400℃, but decreases at 500℃, possibly because the bentonite structure begins to crack at excessively high temperatures, losing some of its adsorption capacity. Example 2

[0037] The experimental procedure for lanthanum-iron modified bentonite was the same as in Example 1, with a calcination temperature of 400℃.

[0038] Preparation method of modified sodium percarbonate particles: Sodium percarbonate particles are coated with sodium silicate solution, that is, SPC is placed in a stirrer and sodium silicate solution with a mass concentration of 40% is added dropwise at a stirring speed of 300r / min, with a mass ratio of about 10:4.5. Then, the particles are dried in a fluidized bed. The effective mass content of the purchased sodium percarbonate particles is above 13%.

[0039] Modified sodium percarbonate, lanthanum-iron modified bentonite, zeolite powder (ET-36) from Lingshou County Aotai Minerals, and cement are mixed in a mass ratio of 4:1:1:0.5. The mixture is then fed into an extrusion granulator and pressed into granules with a particle size controlled between 1 and 20 mm. The finished granules are added at a rate of 0.1 to 1 kg / m³. 3 When added to 5L of tap water and stirred for 30 minutes, the pH rose from 7.2 to 8.5. Example 3

[0040] Lanthanum-iron modified bentonite and modified sodium percarbonate were prepared according to the method in Example 2.

[0041] Modified sodium percarbonate, lanthanum-ferric modified bentonite, zeolite powder (ET-36) from Lingling Shouxian Aotai Mineral Products, and cement are mixed in a mass ratio of 3:1:1:0.5 and fed into an extrusion granulator to be pressed into granules. The particle size is controlled between 1 and 20 mm, and the amount of finished granules added is 0.1 to 1 kg / m³. 3 The solution was added to 5L of tap water and stirred for 30 minutes until the pH stabilized between 7.0 and 7.5. This means the ratio of sodium percarbonate to lanthanum-iron modified bentonite should be less than 3:1. Under these conditions, the pH increase caused by sodium percarbonate dissolving in water can be overcome. Example 4

[0042] formula:

[0043] 15% zeolite powder

[0044] Lanthanum-iron modified bentonite 35%,

[0045] Modified sodium percarbonate 40%,

[0046] Cement 10%.

[0047] Method: Modified sodium percarbonate was dried for half an hour and then mixed with lanthanum carbonate-modified bentonite and zeolite powder. Under the action of binder and cement, the mixture was fed into an extrusion granulator to be pressed into granules. The particle size was controlled between 1 and 20 mm.

[0048] The comprehensive water quality improvement and algae-inhibiting agent was added to the river with severe algae blooms at a dosage of 1 kg / m³. 3 .like Figure 2-4 As shown, after 8 days, the blue-green algae disappeared on a large scale, and all water quality indicators improved significantly. The pH also stabilized from slightly alkaline to neutral, basically achieving the goal of eliminating the inferior water quality. Example 5

[0049] formula:

[0050] 10% zeolite powder

[0051] Lanthanum-iron modified bentonite 30%,

[0052] Sodium percarbonate 40%,

[0053] 10% polyaluminum chloride

[0054] Cement 10%.

[0055] After being pressed into 10-20 mm granules according to the above formula, the granules are evenly sprayed into river waters with excessive nitrogen and phosphorus levels to dissolve them. The dosage added to the water body is 0.8 kg / m³. 3 The addition of 10% polyaluminum chloride essentially eliminated visible microcystis algae and further improved transparency. Total phosphorus decreased from 0.87 mg / L to 0.32 mg / L, and ammonia nitrogen decreased from 1.6 mg / L to 1.2 mg / L. Figure 5 , 6 ).

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A comprehensive water quality improvement and algae-inhibiting agent, characterized in that, The composition by mass percentage is as follows: 15%-40% lanthanum-iron modified bentonite, 30%-55% modified sodium percarbonate, and 20%-40% binder; the mass ratio of lanthanum-iron modified bentonite to modified sodium percarbonate is 1-3:1; the binder is composed of natural porous minerals and cement, and the mass ratio of natural porous minerals to cement is 1-2:1; the modified sodium percarbonate is silicate-coated sodium percarbonate particles. The preparation method of the lanthanum-iron modified bentonite includes the following specific steps: (1) Mix calcium-based bentonite, straw biochar powder and distilled water in a certain proportion, dry and crush to obtain mixed powder; calcine the mixed powder at 300℃-500℃ to obtain biochar modified bentonite. (2) LaCl3·7H2O, Fe(NO3)3·9H2O and biochar-modified bentonite were stirred in distilled water and reacted. Na2CO3 solution was added dropwise until pH=8. Stirring was continued to ensure complete reaction. After the reaction was completed, the mixture was filtered, washed and dried to obtain lanthanum-iron modified bentonite.

2. The comprehensive water quality improvement and algae-inhibiting agent according to claim 1, characterized in that, The comprehensive water quality improvement and algae-inhibiting agent also includes polyaluminum chloride; the comprehensive water quality improvement and algae-inhibiting agent is composed of the following components by mass percentage: 15%-35% lanthanum iron modified bentonite, 30%-45% modified sodium percarbonate, 8%-15% polyaluminum chloride, and 20%-30% binder.

3. The comprehensive water quality improvement and algae-inhibiting agent according to claim 1, characterized in that, In step (1), the mass ratio of calcium-based bentonite, straw biochar powder and distilled water is 3:2:5; and / or, the heating rate of the calcination is 10-15℃ / min, and the calcination time is 1-3h.

4. The comprehensive water quality improvement and algae-inhibiting agent according to claim 1, characterized in that, In step (2), the mass ratio of LaCl3·7H2O, Fe(NO3)3·9H2O, and biochar-modified bentonite is 0.3:0.1:1; and / or, the molar concentration of the Na2CO3 solution is 1 mol / L; and / or, the reaction temperature is 45-50℃; and / or, the drying is to place the solid in an oven at 35℃ for more than 12 h.

5. The comprehensive water quality improvement and algae-inhibiting agent according to claim 1, characterized in that, The method for preparing the modified sodium percarbonate is as follows: sodium percarbonate particles are placed in a stirred mixer, and a sodium silicate solution with a mass concentration of 40% is added dropwise at a stirring speed of 300 r / min. The mass ratio of sodium percarbonate particles to sodium silicate solution is 10:4-5, and the mixture is dried in a fluidized bed.

6. The comprehensive water quality improvement and algae-inhibiting agent according to claim 1, characterized in that, The natural porous mineral is selected from any one or more of zeolite, kaolin, attapulgite, bentonite, and vermiculite powder; and / or, the cement is selected from silicate cement and aluminate cement.

7. The preparation method of the comprehensive water quality improvement and algae-inhibiting agent according to claim 1 or 2, characterized in that, The raw materials are mixed evenly and fed into an extrusion granulator to be pressed into granules. The particle size is controlled between 1 and 20 mm to obtain the finished granules.

8. The application of the comprehensive water quality improvement and algae-inhibiting agent according to claim 1 or 2, characterized in that, Application method: Evenly spray the above-mentioned comprehensive water quality improvement and algae-inhibiting agent granules into the water body; the dosage of the comprehensive water quality improvement and algae-inhibiting agent in the water body is 0.1~1 kg / m³. 3 .

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