Preparation method of magnesium hydroxide-zinc oxide composite oil-water separation membrane

Abstract

The invention relates to the technical field of oil-water separation, in particular to a preparation method of an electro-deposition magnesium hydroxide-zinc oxide composite membrane, which comprises the following steps: taking a high-purity carbon plate as an anode, taking a copper net to be deposited as a cathode, immersing the anode and the cathode into a magnesium chloride-zinc oxide electrolytic solution, and taking a direct-current stabilized power supply as an electro-deposition power supply; and forming the magnesium hydroxide-zinc oxide oil-water separation composite membrane on the surface of the to-be-deposited copper mesh. The method can promote the electro-deposition process of the zinc oxide nanoparticles, and has the advantages of simple process and low cost.

Description

Technical Field

[0001] The invention relates to the technical field of oil-water separation, in particular to a method for preparing a magnesium hydroxide-zinc oxide oil-water separation composite membrane. Background Art

[0002] In today's world, many industries (such as mining, textile, petrochemical and steel industries) produce a large amount of oily wastewater during the production process. In addition, the illegal discharge of industrial and domestic sewage and the frequent occurrence of offshore crude oil spills pose a huge threat to aquatic organisms and cause serious damage to the ecological environment. Therefore, in order to protect the ecological environment and human life safety, it is crucial to find a method to efficiently treat oily wastewater. Membrane separation technology has many advantages in treating oily wastewater, such as small footprint and easy operation. However, the application of membrane separation technology in actual production is still subject to some restrictions. There are three main reasons: First, the occurrence of membrane fouling during the separation process will lead to a significant decrease in the performance of the separation membrane. Second, the chemical stability is poor. The acid, alkali and salt substances in the oily wastewater can easily destroy the micro-nano structure on the surface of the separation membrane, resulting in the decline of surface wettability. Third, the traditional gravity separation method has limitations in performance and is often difficult to achieve the ideal separation effect. It must be supplemented with additional pressure to enhance the separation efficiency. Therefore, there is an urgent need to develop a new type of separation membrane that can efficiently separate a variety of oil-water emulsions under the condition of relying solely on gravity, while also having excellent anti-fouling ability and stable chemical properties to meet the diverse needs in practical applications. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a method for preparing a magnesium hydroxide-zinc oxide composite oil-water separation membrane. The method can promote the electrodeposition process of zinc oxide nanoparticles, has a simple process and low cost.

[0004] To achieve the above object, the technical solution adopted by the present invention is: A method for preparing a magnesium hydroxide-zinc oxide composite oil-water separation membrane comprises the following steps: using a high-purity carbon plate as an anode and a copper mesh to be electrodeposited as a cathode, immersing the anode and the cathode in a magnesium chloride-zinc oxide electrolyte, using a DC regulated power supply as an electrodeposition power supply, and forming a magnesium hydroxide-zinc oxide composite film on the surface of the copper mesh to be electrodeposited.

[0005] Preferably, the preparation method of the magnesium chloride-zinc oxide electrolyte is as follows: first, take a 300 ml electrolytic cell, weigh the reagents according to the electrodeposition formula of 0.8 g / L magnesium chloride and 0.4 g / L zinc oxide nanoparticles, weigh 250 ml of the reagents, and perform ultrasonic dispersion for 10 minutes until the solute is evenly dissolved, and finally obtain the magnesium chloride-zinc oxide electrolyte.

[0006] Preferably, the voltage value selected for the power supply is 15V, 20V or 25V respectively.

[0007] Preferably, a high-purity carbon plate with C ≥ 99.99% is used as the anode, and a pretreated copper mesh is used as the cathode.

[0008] Preferably, the copper mesh pretreatment process is as follows: The copper mesh is washed with deionized water, hydrochloric acid and deionized water in turn, activated with an acid solution, washed with deionized water and then dried to obtain a copper mesh with a smooth surface and a high degree of activation for use.

[0009] The beneficial effects of using the present invention are: 1. The magnesium hydroxide-zinc oxide composite membrane has a high oil-water separation efficiency and strong stability in actual use.

[0010] 2. The preparation process of the magnesium hydroxide-zinc oxide composite film is simple, low in cost and environmentally friendly.

[0011] 3. The magnesium hydroxide-zinc oxide composite film has excellent stability and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the electrodeposition process in the method for preparing the electrodeposited magnesium hydroxide-zinc oxide composite film in the present invention.

[0013] Figure 2 It is a schematic diagram of a scanning electron microscope in the method for preparing the electrodeposited magnesium hydroxide-zinc oxide composite film of the present invention.

[0014] Figure 3 It is a schematic diagram of the test results of the separation efficiency of the magnesium hydroxide-zinc oxide composite membrane in the method for preparing the electrodeposited magnesium hydroxide-zinc oxide composite membrane in the present invention.

[0015] Figure 4 It is a schematic diagram of the intrusion pressure test results of the magnesium hydroxide-zinc oxide composite film in the preparation method of the electrodeposited magnesium hydroxide-zinc oxide composite film in the present invention.

[0016] Figure 5 It is a schematic diagram of the water flux test results of the magnesium hydroxide-zinc oxide composite film in the method for preparing the electrodeposited magnesium hydroxide-zinc oxide composite film in the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the technical solution more clear, the technical solution is further described in detail below in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the technical solution.

[0018] like Figure 1As shown, the present invention proposes a method for preparing an electrodeposited magnesium hydroxide-zinc oxide composite film, specifically, using a high-purity carbon plate as an anode, using a metal material to be electrodeposited as a cathode, immersing the anode and the cathode in a magnesium chloride-zinc oxide electrolyte, and using a DC regulated power supply as an electrodeposition power supply to form a magnesium hydroxide-zinc oxide composite film on the surface of a copper mesh to be electrodeposited.

[0019] The preparation method of the magnesium chloride-zinc oxide electrolyte is as follows: first, take a 300 ml electrolytic cell, weigh reagents according to the electrodeposition formula of 0.8 g / L magnesium chloride and 0.4 g / L zinc oxide nanoparticles, weigh 250 ml of the reagents, perform ultrasonic dispersion for 10 minutes until the solute is evenly dissolved, and finally obtain the magnesium chloride-zinc oxide electrolyte.

[0020] Preferably, the voltage value selected for the power supply is 15V, 20V or 25V respectively.

[0021] A high-purity carbon plate with C ≥ 99.99% is used as the anode, and a pretreated copper mesh is used as the cathode.

[0022] The copper mesh pretreatment process is as follows: the copper mesh is washed with deionized water, hydrochloric acid, and deionized water in sequence, then activated with an acid solution, washed with deionized water, and then dried to obtain a copper mesh with a smooth surface and a high degree of activation for use.

[0023] The magnesium hydroxide-magnesium oxide composite film prepared by the above-mentioned electrodeposition method has an image obtained under a scanning electron microscope as shown in FIG. Figure 2 shown.

[0024] The following examples are used to illustrate in detail the electro-deposition process and effect of the magnesium hydroxide-zinc oxide composite film on the copper mesh of the present invention. Example

[0025] The separation efficiency test results of magnesium hydroxide-zinc oxide composite membrane are as follows Figure 1 As shown, the results show that the composite membrane has a high separation efficiency. The separation efficiency of the magnesium hydroxide-zinc oxide composite membrane reaches 99.4%, which has excellent oil-water separation performance. The specific preparation steps are as follows: Cutting: The pure copper mesh was laser cut into samples of 3×3 cm, so that the size of the copper mesh met the requirements of the electrodeposition experiment.

[0026] Degreasing: Use acetone and anhydrous ethanol to ultrasonically clean for 15 minutes in turn to remove oil stains on the surface of the copper mesh.

[0027] Cleaning: Use hydrochloric acid for ultrasonic cleaning for 15 minutes and deionized water for ultrasonic cleaning for 15 minutes to remove the oxide film and residual hydrochloric acid on the surface of the copper mesh.

[0028] Activation: Activate with 10% sulfuric acid for 25 seconds to obtain a copper mesh with a high degree of activation.

[0029] Cleaning: Ultrasonic cleaning with deionized water for 15 minutes.

[0030] Electrodeposition of magnesium hydroxide-zinc oxide composite film: High-purity carbon plate with Ni≥99.99% was used as anode, pretreated copper mesh was used as cathode, the electrolyte formula was 0.8g / L magnesium chloride, 0.4g / L zinc oxide nanoparticles, voltage was 20V, and electrodeposition time was 10min.

[0031] Cleaning: Ultrasonic cleaning with deionized water for 5 minutes.

[0032] Drying: The prepared magnesium hydroxide-zinc oxide composite film was placed in air at 25°C to dry naturally.

[0033] The prepared magnesium hydroxide-zinc oxide composite membrane significantly reduces the pore size of the copper mesh and improves the hydrophilicity, and has a high oil-water separation efficiency. Example

[0034] The intrusion pressure test results of magnesium hydroxide-zinc oxide composite membrane are as follows Figure 2 As shown, the results show that the composite membrane can withstand a large intrusion pressure and has good stability. The specific preparation steps are as follows: Cutting: The pure copper mesh was laser cut into samples of 3×3 cm, so that the size of the copper mesh met the requirements of the electrodeposition experiment.

[0035] Degreasing: Use acetone and anhydrous ethanol to ultrasonically clean for 15 minutes in turn to remove oil stains on the surface of the copper mesh.

[0036] Cleaning: Use hydrochloric acid for ultrasonic cleaning for 15 minutes and deionized water for ultrasonic cleaning for 15 minutes to remove the oxide film and residual hydrochloric acid on the surface of the copper mesh.

[0037] Activation: Activate with 10% sulfuric acid for 25 seconds to obtain a copper mesh with a high degree of activation.

[0038] Cleaning: Ultrasonic cleaning with deionized water for 15 minutes.

[0039] Electrodeposition of magnesium hydroxide-zinc oxide composite film: High-purity carbon plate with Ni≥99.99% was used as anode, and pretreated copper mesh was used as cathode. The formula of the electrodeposition solution was 0.8g / L magnesium chloride and 0.4g / L zinc oxide nanoparticles. The voltage was 20V and the electrodeposition time was 10min.

[0040] Cleaning: Ultrasonic cleaning with deionized water for 5 minutes.

[0041] Drying: The prepared magnesium hydroxide-zinc oxide composite film was placed in air at 25°C to dry naturally.

[0042] The prepared magnesium hydroxide-zinc oxide composite film has a strong bonding force with the copper mesh and can withstand a strong intrusion pressure. Example

[0043] The water flux test results of magnesium hydroxide-zinc oxide composite membrane are as follows Figure 3 As shown in the figure, it is calculated that the water flux of the magnesium hydroxide-zinc oxide composite membrane reaches (2.99±0.20)×10 5 L·m -2 ·h -1 , with good water permeability. The specific preparation steps are as follows: Cutting: The pure copper mesh was laser cut into samples of 3×3 cm, so that the size of the copper mesh met the requirements of the electrodeposition experiment.

[0044] Degreasing: Use acetone and anhydrous ethanol to ultrasonically clean for 15 minutes in turn to remove oil stains on the surface of the copper mesh.

[0045] Cleaning: Use hydrochloric acid for ultrasonic cleaning for 15 minutes and deionized water for ultrasonic cleaning for 15 minutes to remove the oxide film and residual hydrochloric acid on the surface of the copper mesh.

[0046] Activation: Activate with 10% sulfuric acid for 25 seconds to obtain a copper mesh with a high degree of activation.

[0047] Cleaning: Ultrasonic cleaning with deionized water for 15 minutes.

[0048] Electrodeposition of magnesium hydroxide-zinc oxide composite film: High-purity carbon plate with Ni≥99.99% was used as anode, and pretreated copper mesh was used as cathode. The formula of the electrodeposition solution was 0.8g / L magnesium chloride and 0.4g / L zinc oxide nanoparticles. The voltage was 20V and the electrodeposition time was 10min.

[0049] Cleaning: Ultrasonic cleaning with deionized water for 5 minutes.

[0050] Drying: The prepared magnesium hydroxide-zinc oxide composite film was placed in air at 25°C to dry naturally.

[0051] The hydrophilicity of the prepared magnesium hydroxide-zinc oxide composite membrane is improved and the water permeability is excellent.

[0052] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present technical content. As long as these changes do not deviate from the concept of the present invention, they all fall within the scope of protection of this patent.

Claims

1. A method for preparing an electrodeposited magnesium hydroxide-magnesium oxide oil-water separation composite membrane, characterized in that: A high-purity carbon plate is used as an anode and a copper mesh to be deposited is used as a cathode. The anode and the cathode are immersed in a magnesium chloride-zinc oxide solution. A DC regulated power supply is used as an electrodeposition power supply to form a magnesium hydroxide-zinc oxide composite oil-water separation membrane on the surface of the copper mesh to be deposited.

2. The method for preparing the electrodeposited magnesium hydroxide-zinc oxide oil-water separation composite membrane according to claim 1, characterized in that: The preparation method of the magnesium chloride-zinc oxide electrolyte is as follows: first, take a 300 ml electrolytic cell, weigh reagents according to the electrodeposition formula of 0.8 g / L magnesium chloride and 0.4 g / L zinc oxide, weigh 250 ml of the reagents, perform ultrasonic dispersion for 10 minutes until the solute is evenly dissolved, and finally obtain the magnesium chloride-zinc oxide electrolyte.

3. The method for preparing an electrodeposited magnesium hydroxide-magnesium oxide composite film according to claim 1, wherein: The voltage values ​​selected for the power supply are 15V, 20V or 25V respectively.

4. The method for preparing an electrodeposited magnesium hydroxide-magnesium oxide composite film according to claim 1, wherein: A high-purity carbon plate with C ≥ 99.99% is used as the anode, and a pretreated copper mesh is used as the cathode.

5. The method for preparing an electrodeposited magnesium hydroxide-magnesium oxide composite film according to claim 4, wherein: The process of copper mesh pretreatment is as follows: The copper mesh is washed with deionized water, hydrochloric acid and deionized water in turn, activated with an acid solution, washed with deionized water and then dried to obtain a copper mesh with a smooth surface and a high degree of activation for use.

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