A double-layer hydrophilic-hydrophobic structure organic sewage purifier and its preparation method

Abstract

The present invention relates to a double-layer hydrophilic-hydrophobic organic wastewater purifier and its preparation method. The technical solution comprises: surface-modifying carbonized rice husks with concentrated sulfuric acid and tungsten oxide with an aqueous solution of hexadecyltrimethylammonium bromide, respectively; mixing the two surface-modified substances to produce a tungsten oxide-carbonized rice husk composite. The tungsten oxide-carbonized rice husk composite is added to polyurethane component A and mixed, followed by N,N-dimethylformamide and polyether polyol, and then polyurethane component B and mixed to produce a tungsten oxide-carbonized rice husk foam. Carnauba wax and beeswax are added to anhydrous ethanol and ultrasonically treated to produce a suspension. The suspension is sprayed onto a flat surface on the side of the tungsten oxide-carbonized rice husk foam, which is the larger surface, and dried to produce the double-layer hydrophilic-hydrophobic organic wastewater purifier. The present invention features a simple process, low cost, and low energy consumption. The resulting double-layer hydrophilic-hydrophobic organic wastewater purifier exhibits high water evaporation efficiency and organic matter degradation efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic sewage purifiers, and specifically relates to an organic sewage purifier with a double-layer hydrophilic-hydrophobic structure and a preparation method thereof. Background Art

[0002] Currently, physical adsorption, chemical oxidation and flocculation techniques are used to reduce the content of free organic molecules.

[0003] Solar evaporation technology is an effective method for obtaining clean fresh water. Using sunlight as an energy source, it combines photocatalytic degradation with solar-driven water evaporation to effectively address the shortcomings of current evaporation technologies and prevent the accumulation of organic pollutants during the evaporation process. Furthermore, the introduction of a double-layer hydrophilic-hydrophobic structure prevents the adhesion of organic pollutants and salts to the purifier surface, enabling sustained and stable operation of organic wastewater purifiers. Consequently, it has attracted widespread attention from those skilled in the art. Reports on organic wastewater treatment equipment include:

[0004] The patented technology, "A MXene-functional cotton fabric, its preparation method, and application" (CN116536916A), involves attaching multiple layers of MXene to the surface of cotton fabric via hydrogen bonding through an impregnation process, and then treating pollutants through a photocatalytic reaction. However, the MXene photocatalyst used is expensive, and the hydrogen bonding with the fabric is not tight, resulting in detachment, which reduces its ability to degrade organic pollutants.

[0005] The patented "Biodegradation and Electrocatalytic Degradation Synergistic Treatment Device for Organic Wastewater" (CN116535010A) utilizes electrochemical oxidation to remove pollutants, while the electrolytes required for the electrolysis process are removed through the growth of microalgae. However, electrochemical wastewater treatment consumes a large amount of electricity.

[0006] The patented technology, "A photocatalyst-loaded interfacial photothermal evaporator and its application" (CN115974209A), uses a melamine sponge as the carbon skeleton of the evaporator, onto which the photocatalyst C3N4 is loaded. However, the high-temperature treatment consumes a large amount of energy, and the carbonized melamine sponge is brittle, resulting in poor stability of the evaporator. Summary of the Invention

[0007] The present invention aims to overcome the defects of the prior art and has the purpose of providing a method for preparing a double-layer hydrophilic-hydrophobic structure organic sewage purifier with simple process, low cost and low energy consumption; the double-layer hydrophilic-hydrophobic structure organic sewage purifier prepared by this method has high water evaporation efficiency and organic pollutant degradation efficiency.

[0008] To achieve the above object, the technical solution adopted by the present invention comprises the following steps:

[0009] Step 1: Add 30 to 60 parts by mass of carbonized rice husks to 200 parts by mass of concentrated sulfuric acid, mix well, stir at room temperature for 12 to 18 hours, filter, and dry to obtain surface-modified carbonized rice husks.

[0010] Step 2: Add 30 to 60 parts by mass of tungsten oxide powder to 200 parts by mass of hexadecyltrimethylammonium bromide aqueous solution, filter, and dry to obtain surface-modified tungsten oxide.

[0011] Step 3: Add 20 to 50 parts by mass of the surface-modified carbonized rice husk and 20 to 50 parts by mass of the surface-modified tungsten oxide to 400 parts by mass of water, stir at room temperature for 0.4 to 1 hour, filter, and dry to obtain tungsten oxide composite carbonized rice husk powder.

[0012] Step 4: Add 60 to 90 parts by mass of the tungsten oxide composite carbonized rice husk to 100 parts by mass of polyurethane component A, mix evenly to obtain a mixed solution A; then add 20 to 50 parts by mass of N,N-dimethylformamide and 90 to 120 parts by mass of polyether polyol to the mixed solution A, stir evenly to obtain a mixed solution B; then add 100 parts by mass of polyurethane component B to the mixed solution B, stir evenly, let stand at room temperature for 0.4 to 1 hour, and dry at 90 to 120°C for 12 to 18 hours to obtain a tungsten oxide composite carbonized rice husk foam.

[0013] Step 5: Add 3 to 6 parts by mass of carnauba wax and 1 to 2 parts by mass of beeswax to 200 parts by mass of anhydrous ethanol, stir at 70 to 95° C. for 2 to 3 hours, and ultrasonically treat at room temperature for 2 to 3 hours to obtain a suspension.

[0014] Step 6: spray the suspension onto a large side surface of the tungsten oxide composite carbonized rice husk foam, and dry it at 50-60° C. for 0.4-1 h to obtain a double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0015] The carbonized rice husk preparation method comprises: heating the rice husk at 600-900° C. in a nitrogen atmosphere for 1-4 hours to obtain the carbonized rice husk; the chemical composition of the carbonized rice husk is: C is 25-35wt%, SiO2 is 25-35wt%, and the ignition loss is 30-50wt%; and the particle size of the carbonized rice husk is 100-500nm.

[0016] The concentration of the hexadecyltrimethylammonium bromide aqueous solution is 0.2-0.8 wt %.

[0017] The preparation method of the polyurethane component A is as follows: 0.2 to 0.8 parts by mass of dibutyltin dilaurate and 1 to 4 parts by mass of water are added to 100 parts by mass of toluene diisocyanate, and the mixture is mixed uniformly to obtain the polyurethane component A.

[0018] The preparation method of the polyurethane component B is as follows: 1 to 4 parts by mass of polydimethylsiloxane is added to 100 parts by mass of polyethylene glycol, and the mixture is mixed uniformly to obtain the polyurethane component B.

[0019] The spraying method is as follows: the suspension is loaded into a spray gun, the pressure of the spray gun is set to 20 psi, the nozzle of the spray gun is always kept 5 to 20 cm away from the spraying surface of the tungsten oxide composite carbonized rice husk foam, and the spraying time is 4 to 10 seconds.

[0020] The tungsten oxide composite carbonized rice husk foam is a rectangular parallelepiped.

[0021] Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art:

[0022] (1) The present invention only requires rapid stirring and conventional drying methods, without the need for complex carbonization and heat treatment processes and corresponding equipment. The preparation process is simple and the energy consumption is low. In addition, the main raw material required for the present invention is carbonized rice husk, which is widely available and low in cost.

[0023] (2) The main photothermal medium material used in the present invention is carbonized rice husk. As a biomass waste material with a very wide source, rice husk has a natural micropore and nanopore structure and a high carbon content (30-40wt%). After carbonization, the rice husk has a high light absorption rate and high photothermal conversion efficiency in the ultraviolet-near infrared light region, and can retain the original pore structure. This makes the carbonized rice husk have good adsorption properties for organic pollutants, significantly improving the degradation efficiency of organic pollutants in the double-layer hydrophilic and hydrophobic structure organic wastewater purifier.

[0024] (3) The present invention combines carbonized rice husks with photocatalytic reagents and utilizes the porous structure of carbonized rice husks to provide sufficient reaction sites for photothermal reagents, which can significantly improve the degradation efficiency of organic pollutants in the double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0025] (4) The present invention adopts a double-layer hydrophilic-hydrophobic structure, which can effectively reduce the adhesion of salt and organic pollutants on the evaporator surface by regulating the water wettability of the evaporator surface, thereby improving the stability and water evaporation efficiency of the double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0026] The double-layer hydrophilic-hydrophobic structure organic sewage purifier prepared by the present invention has been tested: the water evaporation efficiency under the sunlight intensity of 1Kw / m2 is 1.1-1.4kg·m -2 ·h-1 , the degradation rate of 5 mg / L Rhodamine B solution is 87-95% in 2.5 hours; it has high water evaporation efficiency and degradation efficiency.

[0027] Therefore, the invention has simple process, low energy consumption and low cost; and the prepared double-layer hydrophilic-hydrophobic structure organic sewage purifier has high water evaporation efficiency and high organic matter degradation efficiency. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments, which does not limit the scope of protection thereof.

[0029] A double-layer hydrophilic-hydrophobic structure organic wastewater purifier and its preparation method. The preparation method described in this specific embodiment is:

[0030] Step 1: Add 30 to 60 parts by mass of carbonized rice husks to 200 parts by mass of concentrated sulfuric acid, mix well, stir at room temperature for 12 to 18 hours, filter, and dry to obtain surface-modified carbonized rice husks.

[0031] Step 2: Add 30 to 60 parts by mass of tungsten oxide powder to 200 parts by mass of hexadecyltrimethylammonium bromide aqueous solution, filter, and dry to obtain surface-modified tungsten oxide.

[0032] Step 3: Add 20 to 50 parts by mass of the surface-modified carbonized rice husk and 20 to 50 parts by mass of the surface-modified tungsten oxide to 400 parts by mass of water, stir at room temperature for 0.4 to 1 hour, filter, and dry to obtain tungsten oxide composite carbonized rice husk powder.

[0033] Step 4: Add 60 to 90 parts by mass of the tungsten oxide composite carbonized rice husk to 100 parts by mass of polyurethane component A, mix evenly to obtain a mixed solution A; then add 20 to 50 parts by mass of N,N-dimethylformamide and 90 to 120 parts by mass of polyether polyol to the mixed solution A, stir evenly to obtain a mixed solution B; then add 100 parts by mass of polyurethane component B to the mixed solution B, stir evenly, let stand at room temperature for 0.4 to 1 hour, and dry at 90 to 120°C for 12 to 18 hours to obtain a tungsten oxide composite carbonized rice husk foam.

[0034] Step 5: Add 3 to 6 parts by mass of carnauba wax and 1 to 2 parts by mass of beeswax to 200 parts by mass of anhydrous ethanol, stir at 70 to 95° C. for 2 to 3 hours, and ultrasonically treat at room temperature for 2 to 3 hours to obtain a suspension.

[0035] Step 6: spray the suspension onto a large side surface of the tungsten oxide composite carbonized rice husk foam, and dry it at 50-60° C. for 0.4-1 h to obtain a double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0036] The carbonized rice husk preparation method is as follows: the rice husk is kept at 600-900° C. in a nitrogen atmosphere for 1-4 hours to obtain the carbonized rice husk; the chemical components of the carbonized rice husk are: C is 25-35wt%, SiO2 is 25-35wt%, and the ignition loss is 30-50wt%.

[0037] The concentration of the hexadecyltrimethylammonium bromide aqueous solution is 0.2-0.8 wt %.

[0038] The preparation method of the polyurethane component A is as follows: 0.2 to 0.8 parts by mass of dibutyltin dilaurate and 1 to 4 parts by mass of water are added to 100 parts by mass of toluene diisocyanate, and the mixture is mixed uniformly to obtain the polyurethane component A.

[0039] The preparation method of the polyurethane component B is as follows: 1 to 4 parts by mass of polydimethylsiloxane is added to 100 parts by mass of polyethylene glycol, and the mixture is mixed uniformly to obtain the polyurethane component B.

[0040] The spraying method is as follows: the suspension is loaded into a spray gun, the pressure of the spray gun is set to 20 psi, the nozzle of the spray gun is always kept 5 to 20 cm away from the spraying surface of the tungsten oxide composite carbonized rice husk foam, and the spraying time is 4 to 10 seconds.

[0041] In this specific implementation mode:

[0042] The tungsten oxide composite carbonized rice husk foam is a rectangular parallelepiped;

[0043] The particle size of carbonized rice husk is 100-500 nm.

[0044] The details will not be described in detail in the embodiments.

[0045] Example 1

[0046] A double-layer hydrophilic-hydrophobic structure organic wastewater purifier and its preparation method. The preparation method described in this embodiment is:

[0047] Step 1: Add 30 parts by mass of carbonized rice husks to 200 parts by mass of concentrated sulfuric acid, mix well, stir at room temperature for 12 hours, filter, and dry to obtain surface-modified carbonized rice husks.

[0048] Step 2: Add 30 parts by mass of tungsten oxide powder to 200 parts by mass of hexadecyltrimethylammonium bromide aqueous solution, filter, and dry to obtain surface-modified tungsten oxide.

[0049] Step 3: Add 20 parts by mass of the surface-modified carbonized rice husk and 20 parts by mass of the surface-modified tungsten oxide to 400 parts by mass of water, stir at room temperature for 0.4 h, filter, and dry to obtain tungsten oxide composite carbonized rice husk powder.

[0050] Step 4: Add 60 parts by mass of the tungsten oxide composite carbonized rice husk to 100 parts by mass of polyurethane component A, mix evenly to obtain a mixed solution A; then add 20 parts by mass of N,N-dimethylformamide and 90 parts by mass of polyether polyol to the mixed solution A, stir evenly to obtain a mixed solution B; then add 100 parts by mass of polyurethane component B to the mixed solution B, stir evenly, let stand at room temperature for 0.4 h, and dry at 90°C for 12 h to obtain a tungsten oxide composite carbonized rice husk foam.

[0051] Step 5: Add 3 parts by mass of carnauba wax and 1 part by mass of beeswax to 200 parts by mass of anhydrous ethanol, stir at 70° C. for 2 h, and ultrasonically treat at room temperature for 2 h to obtain a suspension.

[0052] Step 6: spray the suspension onto a large side surface of the tungsten oxide composite carbonized rice husk foam, and dry it at 50° C. for 0.4 h to obtain a double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0053] The carbonized rice husk is prepared by heating the rice husk at 600° C. in a nitrogen atmosphere for 1 hour to obtain the carbonized rice husk; the chemical composition of the carbonized rice husk is 25wt% of C, 25wt% of SiO2, and 50wt% of loss on ignition.

[0054] The concentration of the hexadecyltrimethylammonium bromide aqueous solution is 0.2 wt %.

[0055] The preparation method of the polyurethane component A is as follows: 0.2 parts by mass of dibutyltin dilaurate and 1 part by mass of water are added to 100 parts by mass of toluene diisocyanate, and the mixture is mixed uniformly to obtain the polyurethane component A.

[0056] The preparation method of the polyurethane component B is as follows: 1 part by mass of polydimethylsiloxane is added to 100 parts by mass of polyethylene glycol, and the mixture is mixed uniformly to obtain the polyurethane component B.

[0057] The spraying method is as follows: the suspension is loaded into a spray gun, the pressure of the spray gun is set to 20 psi, the nozzle of the spray gun is always kept 5 cm away from the spraying surface of the tungsten oxide composite carbonized rice husk foam during spraying, and the spraying time is 4 seconds.

[0058] The water evaporation efficiency of the double-layer hydrophilic-hydrophobic structure organic sewage purifier prepared in this embodiment is 1.15 kg·m-2 ·h -1 , the degradation rate of 5 mg / L Rhodamine B solution was 87.8% in 2.5 h.

[0059] Example 2

[0060] A double-layer hydrophilic-hydrophobic structure organic wastewater purifier and its preparation method. The preparation method described in this embodiment is:

[0061] Step 1: Add 40 parts by mass of carbonized rice husks to 200 parts by mass of concentrated sulfuric acid, mix well, stir at room temperature for 14, filter, and dry to obtain surface-modified carbonized rice husks.

[0062] Step 2: Add 40 parts by mass of tungsten oxide powder to 200 parts by mass of hexadecyltrimethylammonium bromide aqueous solution, filter, and dry to obtain surface-modified tungsten oxide.

[0063] Step 3: Add 30 parts by mass of the surface-modified carbonized rice husk and 30 parts by mass of the surface-modified tungsten oxide to 400 parts by mass of water, stir at room temperature for 0.6 h, filter, and dry to obtain tungsten oxide composite carbonized rice husk powder.

[0064] Step 4: Add 70 parts by mass of the tungsten oxide composite carbonized rice husk to 100 parts by mass of polyurethane component A, mix evenly to obtain a mixed solution A; then add 30 parts by mass of N,N-dimethylformamide and 100 parts by mass of polyether polyol to the mixed solution A, stir evenly to obtain a mixed solution B; then add 100 parts by mass of polyurethane component B to the mixed solution B, stir evenly, let stand at room temperature for 0.6 h, and dry at 100°C for 14 h to obtain a tungsten oxide composite carbonized rice husk foam.

[0065] Step 5: Add 4 parts by mass of carnauba wax and 1.3 parts by mass of beeswax to 200 parts by mass of anhydrous ethanol, stir at 80° C. for 2.3 h, and ultrasonically treat at room temperature for 2.3 h to obtain a suspension.

[0066] Step 6: spray the suspension onto a large side surface of the tungsten oxide composite carbonized rice husk foam, and dry it at 53° C. for 0.6 h to obtain a double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0067] The carbonized rice husk is prepared by heating the rice husk at 700° C. in a nitrogen atmosphere for 2 hours to obtain the carbonized rice husk; the chemical composition of the carbonized rice husk is 30 wt % of C, 25 wt % of SiO 2 , and 45 wt % of loss on ignition.

[0068] The concentration of the hexadecyltrimethylammonium bromide aqueous solution is 0.4 wt %.

[0069] The preparation method of the polyurethane component A is as follows: 0.4 parts by mass of dibutyltin dilaurate and 2 parts by mass of water are added to 100 parts by mass of toluene diisocyanate, and the mixture is mixed uniformly to obtain the polyurethane component A.

[0070] The preparation method of the polyurethane component B is as follows: 2 parts by mass of polydimethylsiloxane is added to 100 parts by mass of polyethylene glycol, and the mixture is mixed uniformly to obtain the polyurethane component B.

[0071] The spraying method is as follows: the suspension is loaded into a spray gun, the pressure of the spray gun is set to 20 psi, the nozzle of the spray gun is always kept 10 cm away from the spraying surface of the tungsten oxide composite carbonized rice husk foam during spraying, and the spraying time is 6 seconds.

[0072] The water evaporation efficiency of the double-layer hydrophilic-hydrophobic structure organic sewage purifier prepared in this embodiment is 1.26 kg·m -2 ·h -1 , and the degradation rate of 5 mg / L Rhodamine B solution was 90.4% within 2.5 hours.

[0073] Example 3

[0074] A preparation method of a double-layer hydrophilic-hydrophobic structure organic sewage purifier, characterized in that the preparation method is:

[0075] A double-layer hydrophilic-hydrophobic structure organic wastewater purifier and its preparation method. The preparation method described in this embodiment is:

[0076] Step 1: Add 50 parts by mass of carbonized rice husks to 200 parts by mass of concentrated sulfuric acid, mix well, stir at room temperature for 16 hours, filter, and dry to obtain surface-modified carbonized rice husks.

[0077] Step 2: Add 50 parts by mass of tungsten oxide powder to 200 parts by mass of hexadecyltrimethylammonium bromide aqueous solution, filter, and dry to obtain surface-modified tungsten oxide.

[0078] Step 3: Add 40 parts by mass of the surface-modified carbonized rice husk and 40 parts by mass of the surface-modified tungsten oxide to 400 parts by mass of water, stir at room temperature for 0.8 h, filter, and dry to obtain tungsten oxide composite carbonized rice husk powder.

[0079] Step 4. Add 80 parts by mass of the tungsten oxide composite carbonized rice husk to 100 parts by mass of polyurethane component A, mix evenly to obtain a mixed solution A; then add 40 parts by mass of N,N-dimethylformamide and 110 parts by mass of polyether polyol to the mixed solution A, stir evenly to obtain a mixed solution B; then add 100 parts by mass of polyurethane component B to the mixed solution B, stir evenly, let stand at room temperature for 0.8 h, and dry at 110°C for 16 h to obtain a tungsten oxide composite carbonized rice husk foam.

[0080] Step 5: Add 5 parts by mass of carnauba wax and 1.6 parts by mass of beeswax to 200 parts by mass of anhydrous ethanol, stir at 90° C. for 2.6 h, and ultrasonically treat at room temperature for 2.6 h to obtain a suspension.

[0081] Step 6: spray the suspension onto a large side surface of the tungsten oxide composite carbonized rice husk foam, and dry it at 56° C. for 0.8 h to obtain a double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0082] The carbonized rice husk is prepared by heating the rice husk at 800° C. in a nitrogen atmosphere for 3 hours to obtain the carbonized rice husk; the chemical composition of the carbonized rice husk is 30 wt % of C, 30 wt % of SiO 2 , and 40 wt % of loss on ignition.

[0083] The concentration of the hexadecyltrimethylammonium bromide aqueous solution is 0.6 wt %.

[0084] The preparation method of the polyurethane component A is as follows: 0.6 parts by mass of dibutyltin dilaurate and 3 parts by mass of water are added to 100 parts by mass of toluene diisocyanate, and the mixture is mixed uniformly to obtain the polyurethane component A.

[0085] The preparation method of the polyurethane component B is as follows: 3 parts by mass of polydimethylsiloxane is added to 100 parts by mass of polyethylene glycol, and the mixture is mixed uniformly to obtain the polyurethane component B.

[0086] The spraying method is as follows: the suspension is loaded into a spray gun, the pressure of the spray gun is set to 20 psi, the nozzle of the spray gun is always kept 15 cm away from the spraying surface of the tungsten oxide composite carbonized rice husk foam during spraying, and the spraying time is 8 seconds.

[0087] The water evaporation efficiency of the double-layer hydrophilic-hydrophobic structure organic sewage purifier prepared in this embodiment is 1.31 kg·m -2 ·h -1 , and the degradation rate of 5 mg / L Rhodamine B solution was 92.1% within 2.5 h.

[0088] Example 4

[0089] A double-layer hydrophilic-hydrophobic structure organic wastewater purifier and its preparation method. The preparation method described in this embodiment is:

[0090] Step 1: Add 60 parts by mass of carbonized rice husks to 200 parts by mass of concentrated sulfuric acid, mix well, stir at room temperature for 18 hours, filter, and dry to obtain surface-modified carbonized rice husks.

[0091] Step 2: Add 60 parts by mass of tungsten oxide powder to 200 parts by mass of hexadecyltrimethylammonium bromide aqueous solution, filter, and dry to obtain surface-modified tungsten oxide.

[0092] Step 3: Add 50 parts by mass of the surface-modified carbonized rice husk and 50 parts by mass of the surface-modified tungsten oxide to 400 parts by mass of water, stir at room temperature for 1 hour, filter, and dry to obtain tungsten oxide composite carbonized rice husk powder.

[0093] Step 4: Add 90 parts by mass of the tungsten oxide composite carbonized rice husk to 100 parts by mass of polyurethane component A, mix evenly to obtain a mixed solution A; then add 50 parts by mass of N,N-dimethylformamide and 120 parts by mass of polyether polyol to the mixed solution A, stir evenly to obtain a mixed solution B; then add 100 parts by mass of polyurethane component B to the mixed solution B, stir evenly, let stand at room temperature for 1 hour, and dry at 120°C for 18 hours to obtain a tungsten oxide composite carbonized rice husk foam.

[0094] Step 5: Add 6 parts by mass of carnauba wax and 2 parts by mass of beeswax to 200 parts by mass of anhydrous ethanol, stir at 95° C. for 3 h, and ultrasonically treat at room temperature for 3 h to obtain a suspension.

[0095] Step 6: spray the suspension onto a large side surface of the tungsten oxide composite carbonized rice husk foam, and dry it at 60° C. for 1 hour to obtain a double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0096] The carbonized rice husk is prepared by heating the rice husk at 900° C. in a nitrogen atmosphere for 4 hours to obtain the carbonized rice husk; the chemical composition of the carbonized rice husk is 35wt% of C, 35wt% of SiO2, and 30wt% of loss on ignition.

[0097] The concentration of the hexadecyltrimethylammonium bromide aqueous solution is 0.8 wt %.

[0098] The preparation method of the polyurethane component A is as follows: 0.8 parts by mass of dibutyltin dilaurate and 4 parts by mass of water are added to 100 parts by mass of toluene diisocyanate, and the mixture is mixed uniformly to obtain the polyurethane component A.

[0099] The preparation method of the polyurethane component B is as follows: 4 parts by mass of polydimethylsiloxane is added to 100 parts by mass of polyethylene glycol, and the mixture is mixed uniformly to obtain the polyurethane component B.

[0100] The spraying method is as follows: the suspension is loaded into a spray gun, the pressure of the spray gun is set to 20 psi, the nozzle of the spray gun is always kept 20 cm away from the spraying surface of the tungsten oxide composite carbonized rice husk foam during spraying, and the spraying time is 10 seconds.

[0101] The water evaporation efficiency of the double-layer hydrophilic-hydrophobic structure organic sewage purifier prepared in this embodiment is 1.38 kg·m -2 ·h -1 , and the degradation rate of 5 mg / L Rhodamine B solution was 94.4% within 2.5 hours.

[0102] Compared with the prior art, this embodiment has the following advantages:

[0103] (1) The present invention only requires rapid stirring and conventional drying methods, without the need for complex carbonization and heat treatment processes, and the preparation process is simple; in addition, the main raw material required by the present invention is carbonized rice husk, which is low in cost.

[0104] (2) The main photothermal medium material used in the present invention is carbonized rice husk. As a biomass waste material with a very wide source, rice husk has a natural micropore and nanopore structure and a high carbon content (30-40wt%). After carbonization, the rice husk has a high light absorption rate and high photothermal conversion efficiency in the ultraviolet-near infrared light region, and can retain the original pore structure, making the carbonized rice husk have good adsorption properties for organic pollutants, significantly improving the degradation efficiency of organic pollutants in the double-layer hydrophilic and hydrophobic structure organic wastewater purifier.

[0105] (3) The present invention combines carbonized rice husks with photocatalytic reagents and utilizes the porous structure of carbonized rice husks to provide sufficient reaction sites for photothermal reagents, which can significantly improve the degradation efficiency of organic pollutants in the double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0106] (4) The present invention adopts a double-layer hydrophilic-hydrophobic structure, which can effectively reduce the adhesion of salt and organic pollutants on the evaporator surface by regulating the water wettability of the evaporator surface, thereby improving the stability and water evaporation efficiency of the double-layer hydrophilic-hydrophobic structure organic sewage purifier.

[0107] The double-layer hydrophilic-hydrophobic structure organic sewage purifier prepared by the present invention has been tested and the water evaporation efficiency is 1.1-1.4 kg·m under the sunlight intensity of 1Kw / m2. -2 ·h -1, the degradation rate of 5 mg / L Rhodamine B solution is 87-95% in 2.5 hours; it has high water evaporation efficiency and degradation efficiency.

[0108] Therefore, the present embodiment has a simple process, low energy consumption and low cost; the prepared double-layer hydrophilic-hydrophobic structure organic sewage purifier has high water evaporation efficiency and high organic matter degradation efficiency.

Claims

1. A method for preparing a double-layer hydrophilic-hydrophobic structure organic sewage purifier, characterized in that The preparation method is: Step 1: Add 30 to 60 parts by mass of carbonized rice husks to 200 parts by mass of concentrated sulfuric acid, mix well, stir at room temperature for 12 to 18 hours, filter, and dry to obtain surface-modified carbonized rice husks; Step 2: Add 30 to 60 parts by mass of tungsten oxide powder to 200 parts by mass of hexadecyltrimethylammonium bromide aqueous solution, filter, and dry to obtain surface-modified tungsten oxide; Step 3: Add 20 to 50 parts by mass of the surface-modified carbonized rice husk and 20 to 50 parts by mass of the surface-modified tungsten oxide to 400 parts by mass of water, stir at room temperature for 0.4 to 1 hour, filter, and dry to obtain tungsten oxide composite carbonized rice husk powder; Step 4: Add 60-90 parts by mass of the tungsten oxide composite carbonized rice husk to 100 parts by mass of polyurethane component A, mix evenly, and obtain a mixed solution A; then add 20-50 parts by mass of N,N-dimethylformamide and 90-120 parts by mass of polyether polyol to the mixed solution A, stir evenly, and obtain a mixed solution B; then add 100 parts by mass of polyurethane component B to the mixed solution B, stir evenly, let stand at room temperature for 0.4-1 hour, and dry at 90-120°C for 12-18 hours to obtain a tungsten oxide composite carbonized rice husk foam; Step 5: Add 3 to 6 parts by mass of carnauba wax and 1 to 2 parts by mass of beeswax to 200 parts by mass of anhydrous ethanol, stir at 70 to 95° C. for 2 to 3 hours, and ultrasonically treat at room temperature for 2 to 3 hours to obtain a suspension; Step 6: spraying the suspension onto a large side surface of the tungsten oxide composite carbonized rice husk foam, and drying at 50-60° C. for 0.4-1 h to obtain a double-layer hydrophilic-hydrophobic structure organic sewage purifier; The polyurethane component A is prepared by adding 0.2 to 0.8 parts by mass of dibutyltin dilaurate and 1 to 4 parts by mass of water to 100 parts by mass of toluene diisocyanate, and mixing them uniformly to obtain the polyurethane component A. The preparation method of the polyurethane component B is as follows: 1 to 4 parts by mass of polydimethylsiloxane is added to 100 parts by mass of polyethylene glycol, and the mixture is mixed uniformly to obtain the polyurethane component B.

2. The method for preparing the double-layer hydrophilic-hydrophobic structure organic wastewater purifier according to claim 1, characterized in that The carbonized rice husk preparation method comprises: heating the rice husk at 600-900° C. in a nitrogen atmosphere for 1-4 hours to obtain the carbonized rice husk; the chemical composition of the carbonized rice husk is: C is 25-35wt%, SiO2 is 25-35wt%, and the loss on ignition is 30-50wt%; and the particle size of the carbonized rice husk is 100-500nm.

3. The method for preparing the double-layer hydrophilic-hydrophobic structure organic wastewater purifier according to claim 1, characterized in that The concentration of the hexadecyltrimethylammonium bromide aqueous solution is 0.2-0.8 wt %.

4. The method for preparing the double-layer hydrophilic-hydrophobic structure organic wastewater purifier according to claim 1, characterized in that The tungsten oxide composite carbonized rice husk foam is a rectangular parallelepiped.

5. The method for preparing the double-layer hydrophilic-hydrophobic structure organic wastewater purifier according to claim 1, characterized in that The spraying method is as follows: the suspension is loaded into a spray gun, the pressure of the spray gun is set to 20 psi, the nozzle of the spray gun is always kept 5 to 20 cm away from the spraying surface of the tungsten oxide composite carbonized rice husk foam during spraying, and the spraying time is 4 to 10 seconds.

6. A double-layer hydrophilic-hydrophobic structure organic sewage purifier, characterized in that The double-layered hydrophilic-hydrophobic structure organic sewage purifier is prepared according to the preparation method of the double-layered hydrophilic-hydrophobic structure organic sewage purifier according to any one of claims 1 to 5.