Preparation method of water purification catalyst for ecological fish tank

Abstract

The invention discloses a preparation method of a water purification catalyst for an ecological fish tank, and belongs to the technical field of water purification. Comprising the following steps: mixing porphyrin tetracarboxylate and a potassium hydroxide solution in a beaker, heating in a water bath kettle, monitoring the dissolution state of porphyrin tetracarboxylate by using a laser pen, and gradually adding the potassium hydroxide solution until porphyrin tetracarboxylate is completely dissolved; s2, adding a hydrochloric acid solution into the solution obtained in the step S1, and observing the Tyndall effect by using a laser pen to ensure that no obvious granular precipitate is formed; and S2, filtering the solution obtained in the step S2, cooling to room temperature, washing with deionized water for three times, and finally drying in a vacuum drying oven to obtain the porphyrin supramolecular photocatalyst. The preparation method comprises the following steps: mixing graphene and a porphyrin photocatalyst according to a mass ratio of 10: 1, dispersing the mixture by using an ultrasonic dispersion instrument, and drying the uniformly dispersed mixture in a vacuum drying oven to finally obtain the graphene composite photocatalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of water purification, and specifically to a preparation method of a water purification catalyst for an ecological fish tank. Background Art

[0002] The existing circulating water purification system of ecological fish tanks mainly removes suspended particles through physical filtration, but has a low removal efficiency for dissolved organic matter, and is prone to cause water eutrophication and excessive growth of algae.

[0003] For example, the photocatalytic water purification fish tank with the Chinese patent publication number CN206238120U includes a fish tank body and a fish tank base; a photocatalytic filter and a water pump communicated with the photocatalytic filter are arranged in the fish tank base; the photocatalytic filter is composed of a fiber cloth filter layer, an activated carbon filter layer, a first photocatalytic treatment layer, and a second photocatalytic treatment layer arranged in a pipeline in sequence; the input end of the photocatalytic filter is communicated with the drain pipe in the fish tank body.

[0004] It uses a photocatalyst for sterilization and disinfection to maintain the environmental hygiene of the fish tank. However, although the traditional photocatalytic technology can degrade organic matter, it has problems such as short catalytic life, easy inactivation, and easy leakage of nanoparticles, which are harmful to aquatic organisms. In addition, commercial photocatalysts have limitations in the visible light response range, charge separation efficiency, etc., and it is difficult to meet the long-term and stable water purification requirements of ecological fish tanks. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a water purification catalyst for an ecological fish tank to solve the problems raised in the above background art.

[0006] In view of the above problems, the technical solution proposed by the present invention is:

[0007] A preparation method of a water purification catalyst for an ecological fish tank includes the following steps:

[0008] S1. Mix tetracarboxylic acid porphyrin and potassium hydroxide solution in a beaker, heat in a water bath, and use a laser pointer to monitor the dissolution state of tetracarboxylic acid porphyrin, and gradually add potassium hydroxide solution until tetracarboxylic acid porphyrin is completely dissolved;

[0009] S2. Add hydrochloric acid solution to the solution obtained in step S1, and observe the Tyndall effect with a laser pointer to ensure that no obvious granular precipitate is formed;

[0010] S3. Filter the solution obtained in step S2 and cool it to room temperature, then wash it three times with deionized water, and finally place it in a vacuum drying oven for drying to finally obtain a porphyrin supramolecular photocatalyst;

[0011] S4. Use ultraviolet-visible spectroscopy to measure the light absorption performance of the porphyrin supramolecular photocatalyst;

[0012] S5. Mix graphene and the porphyrin photocatalyst in a mass ratio of 10:1. Subsequently, use an ultrasonic disperser to disperse the mixture, and then place the evenly dispersed mixture in a vacuum drying oven for drying treatment to finally obtain the graphene composite photocatalyst.

[0013] As a preferred technical solution of the present invention, the step S4 is used to determine the response of the porphyrin supramolecular photocatalyst within the visible light range. When the response of the porphyrin supramolecular photocatalyst in step S4 is not within the visible light range, repeat steps S1-S3 until the response of the porphyrin supramolecular photocatalyst is within the visible light range.

[0014] As a preferred technical solution of the present invention, the initial mixing ratio of the tetracarboxylic acid porphyrin to the potassium hydroxide solution is 1 g:(20 - 30) ml.

[0015] As a preferred technical solution of the present invention, the concentration of the potassium hydroxide solution is 0.5 - 1.5 mol / L, and the concentration of the hydrochloric acid solution is 1 - 2 mol / L.

[0016] As a preferred technical solution of the present invention, the working frequency of the ultrasonic disperser is 20 - 40 kHz, and the working time is 28 - 32 minutes.

[0017] As a preferred technical solution of the present invention, the drying temperature of the vacuum drying oven is 60 - 80 °C, and the drying time is 2 - 3 hours.

[0018] As a preferred technical solution of the present invention, when washing with deionized water, the amount of deionized water used each time is 1 - 1.5 times the volume of the porphyrin and potassium hydroxide mixed solution.

[0019] As a preferred technical solution of the present invention, it further includes a step of grinding the graphene composite photocatalyst. Put the dried catalyst into a mortar and grind it to a particle size of 50 - 100 mesh.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The preparation method of the water purification catalyst for the ecological fish tank solves the problems of low efficiency and poor stability of the traditional photocatalyst through the combination of graphene and the porphyrin supramolecular photocatalyst, and realizes an efficient, safe, and long-lasting water purification effect by combining the visible light transformation and load process optimization of the ecological fish tank, having significant practical value and market prospects. Description of the Drawings

[0021] Figure 1Schematic flow chart of the preparation method of the water purification catalyst for the ecological fish tank disclosed in the embodiments of the present invention;

[0022] Figure 2 Schematic structural diagram of the performance test of the water purification catalyst for the ecological fish tank disclosed in the embodiments of the present invention.

[0023] In the figure: 100, fish tank; 200, circulation pump; 300, first pipeline; 400, second pipeline; 500, filter; 600, LED lamp. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] Please refer to Figure 1 , the present invention provides a technical solution: a preparation method of a water purification catalyst for an ecological fish tank, including the following steps:

[0026] S1. Mix tetracarboxylic acid porphyrin with potassium hydroxide solution in a beaker, heat it in a water bath, monitor the dissolution state of tetracarboxylic acid porphyrin with a laser pointer, and gradually add potassium hydroxide solution until tetracarboxylic acid porphyrin is completely dissolved;

[0027] S2. Add hydrochloric acid solution to the solution obtained in step S1, and observe the Tyndall effect with a laser pointer to ensure that no obvious granular precipitate is formed;

[0028] S3. Filter the solution obtained in step S2 and cool it to room temperature, then wash it three times with deionized water, and finally place it in a vacuum drying oven for drying to finally obtain a porphyrin supramolecular photocatalyst;

[0029] S4. Measure the light absorption performance of the porphyrin supramolecular photocatalyst using ultraviolet-visible spectroscopy;

[0030] S5. Mix graphene and porphyrin photocatalyst in a mass ratio of 10:1, then disperse the mixture using an ultrasonic disperser, and then place the uniformly dispersed mixture in a vacuum drying oven for drying treatment to finally obtain a graphene composite photocatalyst.

[0031] As an embodiment of the present invention, further, step S4 is used to determine the response of the porphyrin supramolecular photocatalyst in the visible light range. When the response of the porphyrin supramolecular photocatalyst in step S4 is not in the visible light range, steps S1 - S3 are repeated until the response of the porphyrin supramolecular photocatalyst is in the visible light range. As an embodiment of the present invention, further, the initial mixing ratio of the tetracarboxylic acid porphyrin to the potassium hydroxide solution is 1 g : (20 - 30) ml.

[0032] As an embodiment of the present invention, further, the concentration of the potassium hydroxide solution is 0.5 - 1.5 mol / L, and the concentration of the hydrochloric acid solution is 1 - 2 mol / L.

[0033] As an embodiment of the present invention, further, the working frequency of the ultrasonic disperser is 20 - 40 kHz, and the working time is 28 - 32 minutes.

[0034] As an embodiment of the present invention, further, the drying temperature of the vacuum drying oven is 60 - 80 °C, and the drying time is 2 - 3 hours.

[0035] As an embodiment of the present invention, further, when washing with deionized water, the amount of deionized water used each time is 1 - 1.5 times the volume of the porphyrin and potassium hydroxide mixed solution.

[0036] As an embodiment of the present invention, further, it further includes a step of grinding the graphene composite photocatalyst. The dried catalyst is put into a mortar and ground until the particle size is 50 - 100 mesh.

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] Please refer to Figure 2 , the present invention provides a technical solution: a method for testing the purification performance of an ecological fish tank for a water purification catalyst for an ecological fish tank. This method tests the purification ability of the graphene composite photocatalyst for the ecological fish tank, including the following steps;

[0039] Step 1: Build an ecological fish tank system. The system includes a fish tank 100, a circulation pump 200, a first pipeline 300, a second pipeline 400, a filter 500, and an LED lamp 600. Connect the output end and the input end of the circulation pump 200 to the second pipeline 400 and the first pipeline 300 respectively. Then connect the second pipeline 400 to the filter 500, and the first pipeline 300 to the fish tank 100. The shell of the filter 500 is made of a light-transmitting material. Multiple layers of filter cotton are arranged inside the filter 500, and the graphene composite photocatalyst is evenly loaded on the surface of the filter cotton, while ensuring that the LED lamp 600 can irradiate the filter 500.

[0040] Step 2: Start the circulation pump 200 to ensure that the water in the fish tank 100 can flow into the filter 500 through the first pipeline 300 and the second pipeline 400, and ensure that the water can pass through the multiple layers of filter cotton and flow into the fish tank 100 under the action of gravity.

[0041] Step 3: Conduct a circulating water test to ensure that no photocatalyst leaks into the water body.

[0042] Step 4: Put 3 - 5 goldfish into the fish tank 100 and place it for one week to turn the water green under the condition of not turning on the circulation pump 200 and the LED lamp 600.

[0043] Step 5: Turn on the circulation pump 200 and the LED lamp 600, and observe the change in the color of the water body.

[0044] Step 6: Collect the aqueous solutions before and after illumination and send them to a testing institution for chemical analysis of the products using gas chromatography - mass spectrometry technology to obtain the purification data of the graphene composite photocatalyst for the ecological fish tank. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] The present invention provides a technical solution: a method for testing the degradation performance of a water purification catalyst for an ecological fish tank, which tests the degradation ability of the graphene composite photocatalyst for organic pollutants. The test is carried out under full - spectrum conditions, using a 500W xenon lamp as the light source, and the average light intensity of the reaction system is 35mW / cm 2 , and organic compounds 2,4 - dichlorophenol, bisphenol A, and phenol are used to simulate the organic pollutants in the fish tank. The specific steps are as follows: Step 1: Take 25mg of the photocatalyst powder and evenly disperse it in 50mL of a 2,4 - dichlorophenol solution with a concentration of 5ppm.

[0046] Step 2: Before illumination, the solution obtained in Step 1 was stirred for 1 hour under dark conditions to achieve adsorption-desorption equilibrium.

[0047] Step 3: After turning on the light, 3 mL of samples were taken at 1-hour intervals. After centrifugal sedimentation and filtration operations, the clear liquid was collected, and the change in phenol concentration was analyzed by high-performance liquid chromatography to evaluate the degradation performance of the material.

[0048] Step 4: The detection mobile phase was adjusted according to different pollutant probe molecules and was prepared by mixing methanol and pure water at different volume ratios. For phenol, it was 55%:45%, for 2,4-dichlorophenol, it was 75%:25%, and for bisphenol A, it was 70%:30%. The flow rate was 1 mL / min for all.

[0049] Step 5: Record the degree of pollutant degradation of the graphene composite photocatalyst under the full spectrum and the apparent rate constants of 0.371 h-1 for 2,4-dichlorophenol, 0.342 h-1 for bisphenol A, and 0.057 h-1 for phenol. In this example, the high-performance liquid chromatograph was LC-20AT produced by Shimadzu Corporation of Japan, with a UV detector, the detection wavelength was 270 nm, and the chromatographic column was an XBP-C18 column.

[0050] Test results: The ultra-large specific surface area and excellent electron transport performance of graphene significantly improved the photocatalytic efficiency. The apparent degradation rate constants for pollutants such as 2,4-dichlorophenol and bisphenol A reached 0.371 h -1 and 0.342 h -1 ; By degrading eutrophic organic matter, the nutrient source for algal reproduction was blocked, and at the same time, the active oxygen species generated by photocatalysis directly damaged the algal cell structure; The composite photocatalyst avoided nanoparticle leakage through optimized formulation and loading processes, ensuring harmlessness to fish; The composite photocatalyst still maintained more than 90% of its catalytic activity after continuous operation for 30 days.

Claims

1. A preparation method of a water purification catalyst for an ecological fish tank, characterized in that, It includes the following steps: S1. Mix tetracarboxylic acid porphyrin with potassium hydroxide solution in a beaker, heat it in a water bath, monitor the dissolution state of tetracarboxylic acid porphyrin with a laser pointer, and gradually add potassium hydroxide solution until tetracarboxylic acid porphyrin is completely dissolved; S2. Add hydrochloric acid solution to the solution obtained in step S1, and observe the Tyndall effect with a laser pointer to ensure that no obvious granular precipitate is formed; S3. Filter the solution obtained in step S2 and cool it to room temperature, then wash it three times with deionized water, and finally place it in a vacuum drying oven for drying to finally obtain a porphyrin supramolecular photocatalyst; S4. Use ultraviolet-visible spectroscopy to determine the light absorption performance of the porphyrin supramolecular photocatalyst; S5. Mix graphene and porphyrin photocatalyst in a mass ratio of 10:1, then use an ultrasonic disperser to disperse the mixture, and then place the uniformly dispersed mixture in a vacuum drying oven for drying treatment to finally obtain a graphene composite photocatalyst.

2. The preparation method of a water purification catalyst for an ecological fish tank according to claim 1, characterized in that, The step S4 is used to determine the response of the porphyrin supramolecular photocatalyst in the visible light range. When the response of the porphyrin supramolecular photocatalyst in step S4 is not in the visible light range, repeat steps S1-S3 until the response of the porphyrin supramolecular photocatalyst is in the visible light range.

3. The preparation method of a water purification catalyst for an ecological fish tank according to claim 1, characterized in that, The initial mixing ratio of the tetracarboxylic acid porphyrin to the potassium hydroxide solution is 1 g:(20-30) ml.

4. The preparation method of a water purification catalyst for an ecological fish tank according to claim 1, characterized in that, The concentration of the potassium hydroxide solution is 0.5-1.5 mol / L, and the concentration of the hydrochloric acid solution is 1-2 mol / L.

5. The preparation method of a water purification catalyst for an ecological fish tank according to claim 1, characterized in that, The working frequency of the ultrasonic disperser is 20-40 kHz, and the working time is 28-32 minutes.

6. The preparation method of a water purification catalyst for an ecological fish tank according to claim 1, characterized in that, The drying temperature of the vacuum drying oven is 60-80 °C, and the drying time is 2-3 hours.

7. The preparation method of a water purification catalyst for an ecological fish tank according to claim 1, characterized in that, When washing with deionized water, the amount of deionized water used each time is 1-1.5 times the volume of the mixed solution of porphyrin and potassium hydroxide.

8. The preparation method of a water purification catalyst for an ecological fish tank according to claim 1, characterized in that, It also includes a step of grinding the graphene composite photocatalyst. Put the dried catalyst into a mortar and grind it until the particle size is 50-100 mesh.

Images