Titanium dioxide photocatalyst for treating aquaculture wastewater

Abstract

The present application belongs to the technical field of photocatalyst, and particularly relates to a titanium dioxide photocatalyst for treating aquaculture wastewater, which is prepared by dispersing a boron-silicon nonmetallic framework in a silicone solution through ultrasonic, adding a 10% sodium hydroxide solution dropwise to adjust the pH value, gradually adding titanium dioxide microsphere powder in the stirring process, and treating the product after a period of reaction, filtration, washing and drying to obtain a modified titanium-based photocatalyst. The titanium dioxide photocatalyst for treating aquaculture wastewater is prepared by taking the modified titanium-based photocatalyst as the main body, wherein the boron-silicon nonmetallic framework is prepared by the following steps: dispersing tributyl borate in a 10% acetone solution through ultrasonic, slowly adding a 1 mol / L tetraethyl orthosilicate solution dropwise, transferring to a high-pressure autoclave, and reacting under certain conditions to obtain the boron-silicon nonmetallic framework. The titanium dioxide photocatalyst for treating aquaculture wastewater prepared by taking the modified titanium-based photocatalyst as the main body can adapt to the complex environment in the aquaculture wastewater, is not prone to inactivation, and has a long service life.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photocatalysts, and particularly relates to a titanium dioxide photocatalyst for treating aquaculture wastewater. BACKGROUND

[0002] A photocatalyst is a general term for a semiconductor material with photocatalytic function, represented by nanoscale titanium dioxide, which can produce a strong oxidizing substance under light irradiation and can act on organic compounds, some inorganic compounds, bacteria, viruses and the like. The photocatalyst can be applied to multiple fields. In the aspect of environmental governance, the photocatalyst can be used for photocatalytic degradation of organic pollutants, photocatalytic oxidation of harmful gases and photocatalytic sterilization and the like. In the aspect of energy conversion, the photocatalyst can be applied to photovoltaic cells and water splitting to produce hydrogen and the like. In the aspect of organic synthesis, the photocatalyst can be used for photocatalytic organic reactions and photocatalytic synthesis of organic molecules and the like. Aquaculture wastewater refers to wastewater containing organic matter, inorganic matter and microorganisms generated in the process of aquaculture. The aquaculture wastewater contains a large amount of organic matter such as feed residues and feces, resulting in a high content of ammonia nitrogen in the wastewater. In addition, the aquaculture wastewater contains a large amount of nutrients, causing microbial pollution, and the nitrogen and phosphorus elements in the wastewater cause eutrophication of the water body, and the sulfur element causes the water body to emit a foul odor.

[0003] In the prior art, the traditional methods for treating aquaculture wastewater include biological methods, physical methods and chemical methods. The biological treatment method needs a long treatment time and is sensitive to temperature, oxygen and pH and the like. The physical treatment method has a poor removal effect on organic matter and cannot remove dissolved organic matter and inorganic pollutants in the wastewater. The chemical treatment method needs to use a large amount of chemical agents, and the utilization rate of the chemical agents is low due to the complex environment in the water body. The chemical reagent for purifying the water body mainly uses a flocculant, and the flocculation effect of the flocculant is limited, the service life is short, and the flocculant cannot be recycled. SUMMARY

[0004] The application aims to provide a titanium dioxide photocatalyst for treating aquaculture wastewater. The titanium dioxide photocatalyst is prepared by dispersing a boron-silicon nonmetallic skeleton in a silicone solution through ultrasonic dispersion, adding a 10% sodium hydroxide solution to adjust the pH value, gradually adding titanium dioxide microsphere powder in the stirring process, reacting for 3-4 hours, and then performing filtration, washing and drying to obtain a modified titanium-based photocatalyst.

[0005] The technical problem to be solved by the application is that the flocculation effect of a flocculant is limited and the service life is short.

[0006] The object of the application can be achieved by the following technical scheme.

[0007] The application discloses a titanium dioxide photocatalyst for treating aquaculture wastewater, which is composed of the following components in mass fraction: modified titanium-based photocatalyst 80-85%, activated carbon 5-10%, magnesium carbonate 2-4%, polyaluminum chloride 2-5% and epoxy resin 1-2%.

[0008] Further, the modified titanium-based photocatalyst is prepared by the following steps:

[0009] The boron-silicon nonmetallic skeleton is ultrasonically dispersed in a silicone solution, 10% sodium hydroxide solution is added dropwise to adjust the pH value to 11-12, and titanium dioxide microsphere powder is gradually added in the stirring process; then the mixture is transferred into a 75 DEG C constant-temperature box, and is reacted for 3-4 hours under the condition of 1000 rpm-2000 rpm; after filtration, washing and drying, the modified titanium-based photocatalyst is obtained.

[0010] Further, the boron-silicon nonmetallic skeleton is prepared by the following steps:

[0011] The tributyl borate is ultrasonically dispersed in 10% acetone solution, 1 mol / L tetraethyl silicate solution is slowly added dropwise, and the pH value is adjusted to 4-6; then the mixture is transferred into a stainless steel Teflon-lined autoclave, and is reacted for 6-8 hours under the condition of 150 DEG C-180 DEG C; after washing and drying, the boron-silicon nonmetallic skeleton is obtained.

[0012] The titanium dioxide microsphere powder refers to a micron-level titanium dioxide material in a spherical morphology.

[0013] Further, the titanium dioxide microsphere powder is prepared by the following steps:

[0014] Acetylacetone is added into anhydrous ethanol, and butyl titanate is slowly added dropwise; after uniform stirring, a mixed solution A is obtained; then hydrochloric acid solution is added into anhydrous ethanol, and the mixture is stirred to obtain a mixed solution B; the mixed solution A is introduced into the mixed solution B through a glass rod, and the stirring is continuously performed for 15-20 minutes; finally, the uniformly stirred solution is prepared into the titanium dioxide microsphere powder through a spray pyrolysis device.

[0015] The amount ratio of the boron-silicon nonmetallic skeleton, the silicone solution and the titanium dioxide microsphere powder is (10-15) g:(20-30) mL:(5-7) g.

[0016] The volume ratio of the tributyl borate, the acetone solution and the tetraethyl silicate solution is (2-4):(6-8):(1-5).

[0017] The volume ratio of the acetylacetone, the butyl titanate, the hydrochloric acid solution and the anhydrous ethanol is (1-2):(10-20):(2.5-5):(45-90).

[0018] Further, the modified titanium-based photocatalyst is prepared by the following steps:

[0019] The modified titanium-based photocatalyst, activated carbon, magnesium carbonate, polyaluminum chloride and epoxy resin of corresponding mass fraction are weighed and uniformly stirred, then are put into a mixer, and after being fully mixed, are put into a mold to be compression molded to obtain the titanium dioxide photocatalyst for treating aquaculture wastewater.

[0020] The present application has the following beneficial effects:

[0021] 1. In the technical scheme of the present application, the boron-silicon non-metallic framework has a porous structure and provides a high specific surface area by virtue of the three-dimensional structure composed of Z-shaped channels and elliptical straight channels intersecting with the Z-shaped channels, so as to improve the activity and efficiency of the photocatalyst by using the boron-silicon non-metallic framework as a carrier. In addition, the boron-silicon non-metallic framework has good chemical stability and can stably load the photocatalyst under different reaction conditions, so that the photocatalyst is not easily deactivated and has a long service life in the complex environment of aquaculture wastewater.

[0022] 2. In the technical scheme of the present application, the micron-sized titanium dioxide material in a spherical shape is adsorbed in the boron-silicon non-metallic structure, so that the photocatalyst does not aggregate into a group in the aquaculture wastewater and maintains a good dispersion state. The spherical morphology helps to improve the specific surface area of the titanium dioxide material, thereby improving the stability of the titanium dioxide material loaded in the boron-silicon non-metallic structure. The poisoning of metals by elements such as sulfur, nitrogen and phosphorus is generally manifested by the interaction between the lone pair electrons on the sulfur atom and the active metal, such as the adsorption of sulfides on the active metal, covering the active center sites or dissociative adsorption on the metal, strong bonding between the metal, resulting in deactivation of the catalyst. The titanium dioxide microspheres with the boron-silicon non-metallic framework as a carrier can avoid the phenomenon of deactivation of the photocatalyst caused by the adsorption of sulfides and the like on the active center. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] Embodiment 1

[0025] The titanium dioxide microspheres powder is prepared by the following steps:

[0026] First, 1 ml of acetylacetone is dropped into 35 ml of anhydrous ethanol and stirred to obtain a mixed solution, then 10 ml of butyl titanate is slowly added to the prepared mixed solution to obtain mixed solution A; 2.5 ml of hydrochloric acid solution is added to 10 ml of anhydrous ethanol and stirred to obtain mixed solution B, then mixed solution A is introduced into mixed solution B through a glass rod, and stirring is continued for 15 min. Finally, the uniformly stirred solution is prepared into titanium dioxide microsphere powder through a spray pyrolysis device at 200°C.

[0027] Example 2

[0028] The titanium dioxide microsphere powder is prepared by the following steps:

[0029] First, 1.5 ml of acetylacetone is dropped into 52.5 ml of anhydrous ethanol and stirred to obtain a mixed solution, then 15 ml of butyl titanate is slowly added to the prepared mixed solution to obtain mixed solution A; 3.75 ml of hydrochloric acid solution is added to 15 ml of anhydrous ethanol and stirred to obtain mixed solution B, then mixed solution A is introduced into mixed solution B through a glass rod, and stirring is continued for 15 min. Finally, the uniformly stirred solution is prepared into titanium dioxide microsphere powder through a spray pyrolysis device at 200°C.

[0030] Example 3

[0031] The titanium dioxide microsphere powder is prepared by the following steps:

[0032] First, 2 ml of acetylacetone is dropped into 70 ml of anhydrous ethanol and stirred to obtain a mixed solution, then 20 ml of butyl titanate is slowly added to the prepared mixed solution to obtain mixed solution A; 5 ml of hydrochloric acid solution is added to 20 ml of anhydrous ethanol and stirred to obtain mixed solution B, then mixed solution A is introduced into mixed solution B through a glass rod, and stirring is continued for 15 min. Finally, the uniformly stirred solution is prepared into titanium dioxide microsphere powder through a spray pyrolysis device at 200°C.

[0033] Example 4

[0034] The borosilicate non-metallic framework is prepared by the following steps:

[0035] 2 mL of tributyl borate is ultrasonically dispersed in 6 mL of 10% acetone solution, 1 mL of 1 mol / L tetraethyl silicate solution is slowly added, the pH value is adjusted to 5, and then it is transferred to a stainless steel Teflon-lined autoclave for reaction at 150°C for 6 h, washed, and dried to obtain a borosilicate non-metallic framework.

[0036] Example 5

[0037] The borosilicate non-metallic framework is prepared by the following steps:

[0038] Boric acid tributyl ester 3 mL was ultrasonically dispersed in 7 mL of 10% acetone solution, 2.5 mL of 1 mol / L tetraethyl silicate solution was added dropwise, pH was adjusted to 5, and the mixture was transferred to a stainless steel Teflon-lined autoclave and reacted at 150°C for 6 h. The product was washed and dried to obtain a boron-silicon nonmetallic skeleton.

[0039] Example 6

[0040] A boron-silicon nonmetallic skeleton was prepared by the following steps:

[0041] Boric acid tributyl ester 4 mL was ultrasonically dispersed in 8 mL of 10% acetone solution, 5 mL of 1 mol / L tetraethyl silicate solution was added dropwise, pH was adjusted to 5, and the mixture was transferred to a stainless steel Teflon-lined autoclave and reacted at 150°C for 6 h. The product was washed and dried to obtain a boron-silicon nonmetallic skeleton.

[0042] Example 7

[0043] A modified titanium-based photocatalyst was prepared by the following steps:

[0044] The boron-silicon nonmetallic skeleton prepared in Example 4, 10 g, was ultrasonically dispersed in 20 mL of silicone solution, 10% sodium hydroxide solution was added dropwise to adjust pH to 11, and 5 g of the titanium dioxide microsphere powder prepared in Example 1 was gradually added during stirring. The mixture was transferred to a 75°C thermostat and reacted at 1000 rpm for 3 h. After treatment by filtration, washing and drying, a modified titanium-based photocatalyst was obtained.

[0045] Example 8

[0046] A modified titanium-based photocatalyst was prepared by the following steps:

[0047] The boron-silicon nonmetallic skeleton prepared in Example 5, 12.5 g, was ultrasonically dispersed in 25 mL of silicone solution, 10% sodium hydroxide solution was added dropwise to adjust pH to 11, and 6 g of the titanium dioxide microsphere powder prepared in Example 2 was gradually added during stirring. The mixture was transferred to a 75°C thermostat and reacted at 1000 rpm for 3 h. After treatment by filtration, washing and drying, a modified titanium-based photocatalyst was obtained.

[0048] Example 9

[0049] A modified titanium-based photocatalyst was prepared by the following steps:

[0050] The boron-silicon nonmetallic skeleton prepared in Example 6, 15 g, was ultrasonically dispersed in 30 mL of silicone solution, 10% sodium hydroxide solution was added dropwise to adjust pH to 11, and 7 g of the titanium dioxide microsphere powder prepared in Example 3 was gradually added during stirring. The mixture was transferred to a 75°C thermostat and reacted at 1000 rpm for 3 h. After treatment by filtration, washing and drying, a modified titanium-based photocatalyst was obtained.

[0051] Example 10

[0052] The modified titanium-based photocatalyst prepared in Example 7, activated carbon 10%, magnesium carbonate 2%, polyaluminum chloride 2% and epoxy resin 1% were weighed and stirred uniformly, and then put into a mixer. After sufficient mixing, the mixture was put into a mold and compression molded to prepare a titanium dioxide photocatalyst for treating aquaculture wastewater.

[0053] Example 11

[0054] The modified titanium-based photocatalyst prepared in Example 8, activated carbon 10%, magnesium carbonate 2%, polyaluminum chloride 2% and epoxy resin 1% were weighed and stirred uniformly, and then put into a mixer. After sufficient mixing, the mixture was put into a mold and compression molded to prepare a titanium dioxide photocatalyst for treating aquaculture wastewater.

[0055] Example 12

[0056] The modified titanium-based photocatalyst prepared in Example 9, activated carbon 10%, magnesium carbonate 2%, polyaluminum chloride 2% and epoxy resin 1% were weighed and stirred uniformly, and then put into a mixer. After sufficient mixing, the mixture was put into a mold and compression molded to prepare a titanium dioxide photocatalyst for treating aquaculture wastewater.

[0057] Comparative Example 1

[0058] The commercially available titanium dioxide photocatalyst, activated carbon 10%, magnesium carbonate 2%, polyaluminum chloride 2% and epoxy resin 1% were weighed and stirred uniformly, and then put into a mixer. After sufficient mixing, the mixture was put into a mold and compression molded.

[0059] Comparative Example 2

[0060] The commercially available flocculant, activated carbon 10%, magnesium carbonate 2%, polyaluminum chloride 2% and epoxy resin 1% were weighed and stirred uniformly, and then put into a mixer. After sufficient mixing, the mixture was put into a mold and compression molded.

[0061] The aquaculture wastewater was randomly selected and divided into six groups. Five groups were added with the products of Examples 10-12 and Comparative Examples 1-2, and the other group was a control group. Some of the project indicators are shown in Table 1:

[0062] Table 1. Test results of some items (unit: mg / L)

[0063]

[0064] From table 1, it can be seen that the indexes of some items of examples 10-12 meet the class I standard, and the indexes of some items of comparative examples 1-2 only meet the class III or IV standard, and some items do not meet the standard, and the effect of examples 10-12 is better than that of comparative examples 1-2. It is illustrated that by dispersing the boron-silicon non-metallic skeleton in the silicone solution by ultrasonic, adding 10% sodium hydroxide solution dropwise to adjust the pH value, gradually adding titanium dioxide microsphere powder in the stirring process, reacting for 3-4 hours, and then treating by filtering, washing and drying, the modified titanium-based photocatalyst is obtained, and the titanium dioxide photocatalyst for treating aquaculture wastewater prepared by using the modified titanium-based photocatalyst as the main body has excellent purification effect on aquaculture wastewater.

[0065] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as it does not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A titanium dioxide photocatalyst for treating aquaculture wastewater, characterized in that, The composition is based on the following mass fractions: 80%-85% modified titanium-based photocatalyst, 5%-10% activated carbon, 2%-4% magnesium carbonate, 2%-5% polyaluminum chloride, and 1%-2% epoxy resin; The modified titanium-based photocatalyst is prepared by the following steps: A borosilicate nonmetallic framework was ultrasonically dispersed in a silicone solution, and a 10% sodium hydroxide solution was added dropwise to adjust the pH value to 11-12. Titanium dioxide microsphere powder was gradually added during stirring, and the mixture was transferred to a 75℃ constant temperature oven and reacted at 1000rpm-2000rpm for 3-4 hours. After filtration, washing and drying, the modified titanium-based photocatalyst was obtained. The borosilicate nonmetallic framework is prepared by the following steps: Tributyl borate was ultrasonically dispersed in a 10% acetone solution, and a 1 mol / L tetraethyl silicate solution was slowly added dropwise. The pH value was adjusted to 4-6, and the mixture was transferred to a stainless steel polytetrafluoroethylene-lined autoclave. The reaction was carried out at 150℃-180℃ for 6-8 hours. The mixture was then washed and dried to obtain a borosilicate nonmetallic framework. The titanium dioxide photocatalyst is prepared by the following steps: Weigh out the corresponding mass fractions of modified titanium-based photocatalyst, activated carbon, magnesium carbonate, polyaluminum chloride and epoxy resin, stir evenly, put them into a mixer, mix thoroughly, place them in a mold and press to form a titanium dioxide photocatalyst for treating aquaculture wastewater.

2. The titanium dioxide photocatalyst for treating aquaculture wastewater according to claim 1, characterized in that, Titanium dioxide microsphere powder refers to micron-sized titanium dioxide materials with a spherical morphology.

3. The titanium dioxide photocatalyst for treating aquaculture wastewater according to claim 1, characterized in that, Titanium dioxide microsphere powder is prepared by the following steps: Acetylacetone was added to anhydrous ethanol, and tetrabutyl titanate was slowly added dropwise. The mixture was stirred until homogeneous to obtain mixture A. Hydrochloric acid solution was then added to anhydrous ethanol and stirred to obtain mixture B. Mixture A was then introduced into mixture B through a glass rod and stirred continuously for 15-20 minutes. Finally, the homogeneous solution was processed through a spray pyrolysis device to prepare titanium dioxide microsphere powder.

4. The titanium dioxide photocatalyst for treating aquaculture wastewater according to claim 1, characterized in that, The ratio of borosilicate nonmetallic framework, silicone solution and titanium dioxide microsphere powder is (10-15) g: (20-30) mL: (5-7) g.

5. The titanium dioxide photocatalyst for treating aquaculture wastewater according to claim 1, characterized in that, The volume ratio of tributyl borate, acetone solution and tetraethyl silicate solution is (2-4):(6-8):(1-5).

6. The titanium dioxide photocatalyst for treating aquaculture wastewater according to claim 3, characterized in that, The volume ratio of acetylacetone, tetrabutyl titanate, hydrochloric acid solution and anhydrous ethanol is (1-2):(10-20):(2.5-5):(45-90).

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