CN116747833B - Activated carbon wood fiber foam and preparation method thereof - Google Patents

Abstract

The invention discloses an activated carbon wood fiber foam and a preparation method thereof, and relates to the field of organic polymer materials, wherein the preparation method of the activated carbon wood fiber comprises the following steps: grinding the wood material to obtain wood powder, and adding clear water into the wood powder to obtain a wood suspension; adding sodium chloride solution into the wood suspension, performing auxiliary forming by using salt ions, and then performing stirring treatment to obtain a mixed solution I; adding an active carbon solution into the first mixed solution, and stirring to change the first mixed solution into a black second mixed solution; and performing ultrasonic crushing treatment on the mixed solution II to break fibers in the mixed solution II, and finally performing freeze drying on the mixed solution II to obtain the activated carbon wood foam. The invention uses wood as main raw material, and stirs and mixes nontoxic and harmless active carbon and wood, the active carbon wood foam prepared has better mechanical property and photo-thermal conversion property, the preparation method is simple, the materials are convenient, the control is easy, and the cost is low.

Description

Activated carbon wood fiber foam and preparation method thereof

Technical Field

The invention relates to the field of organic polymer materials, in particular to an activated carbon wood fiber foam and a preparation method thereof.

Background Art

Water resources on Earth account for 71% of the Earth's surface. Natural evaporation from rivers, oceans, lakes and transpiration from plants provide a large amount of fresh water resources to the world. Fresh water is a global issue of strategic significance and is essential to human survival and socio-economic development. Water is one of the most abundant compounds on Earth. So far, many people are suffering from fresh water shortages due to population growth, climate change and rampant pollution in the past few decades. In the process of continuous technological development, researchers have successively developed technologies including thermal distillation, reverse osmosis, membrane filtration, electrodialysis and photocatalysis. Among them, thermal distillation technology can effectively convert salt water into fresh water resources and obtain usable pure water. Solar evaporation uses photothermal materials to convert solar energy into heat for water evaporation and produce high-quality drinking fresh water. This is a promising desalination technology that can alleviate the problem of fresh water shortage in a green and sustainable way.

In solar evaporation, photothermal materials have received extensive attention. These materials can be roughly divided into three categories: carbon-based materials, such as carbon black, graphite, carbon nanotubes, graphene, graphene oxide and reduced graphene oxide; plasma-based materials, such as metals, metal oxides, metal nitrides, and polymer-based materials, such as polypyrrole and polydopamine. However, most of these materials cannot be used alone, such as graphite and graphene. In addition, these carbon materials are expensive to make solar drivers and are inconvenient to obtain, so they have not been put into practical use, such as graphene oxide and reduced graphene oxide.

Summary of the invention

In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide an activated carbon wood foam treated with solar desalination and a preparation method thereof. The wood foam modified by the method of the present invention has the advantages of good water purification effect, low cost, abundant sources and simple operation, which conforms to the clean production concept of treating waste with waste in the current environment and has good environmental and social benefits.

The purpose of the present invention can be achieved through the following technical solutions:

A method for preparing activated carbon wood fiber foam, the preparation method comprising the following steps:

The wood material is ground to obtain wood powder, and water is added to the wood powder to obtain a wood suspension; a sodium chloride solution is added to the wood suspension to assist in forming with salt ions, and then stirred to obtain a mixed solution 1; an activated carbon solution is added to the mixed solution 1, and stirred to change the mixed solution 1 into a black mixed solution 2; the mixed solution 2 is subjected to ultrasonic crushing to break the fibers in the mixed solution 2, and finally the mixed solution 2 is freeze-dried to obtain an activated carbon wood foam;

Among them: the ratio of wood powder to water is 1:20, the ratio of wood suspension to sodium chloride solution is 30:1, and the ratio of mixed solution 1 to activated carbon solution is 1:1.

Preferably, the wood material is forest waste.

Preferably, the particle size of the wood powder is less than 200 mesh.

Preferably, the stirring conditions after adding sodium chloride to the suspension are: temperature of 20° C., stirring for 1-2 h, and a rotation speed of 300 r/min.

Preferably, the concentration of the sodium chloride solution is 100 ml 5 wt %.

Preferably, the activated carbon solution is prepared by mixing activated carbon and distilled water, wherein the activated carbon is powdered activated carbon, the activated carbon particle size is less than 200 mesh, and the ratio of activated carbon to distilled water is 1:20.

Preferably, the activated carbon solution is added to the mixed solution 1, and the stirring conditions for stirring are: temperature of 20° C., stirring for 1-2 hours, and a speed of 300 r/min:

Preferably, the ultrasonic cell disruptor is used for the ultrasonic disruption. When in use, the power ratio of the ultrasonic cell disruptor is set to 20%, and the ultrasonic disruption time is 10 minutes.

Preferably, the freeze-drying step is as follows: first freezing the mixed solution 2 at -40°C for 6 hours to freeze-form the mixed solution 2, and then freeze-drying the formed mixed solution 2 under vacuum conditions for 48 hours to sublime the water.

Preferably, the activated carbon wood foam is prepared by a method for preparing activated carbon wood foam.

Beneficial effects of the present invention:

(1) Traditionally, biomass materials are modified for water treatment, but the scale of the modification is affected by the characteristics of the biomass itself and cannot be used for large-scale water treatment. The present application uses wood as the raw material to control the size of the material, and can achieve large-scale production and large-scale desalination treatment.

(2) The activated carbon wood foam prepared by wood modification using activated carbon in the present application has a good desalination treatment effect, has the characteristics of acid, alkali and high salt resistance, and the treatment efficiency can reach more than 90%.

(3) The material used in this application is biomass material, which is a naturally degradable material and does not cause secondary pollution to the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1: Physical pictures of activated carbon wood foam with activated carbon content of 0%, 10%, 20%, 30%, 40% and 50%;

Figure 2: Infrared spectra of wood foam with different activated carbon contents;

Figure 3: Indoor evaporation mass loss and evaporation rate diagram of wood foam with different activated carbon contents; (a) is the mass loss diagram of activated carbon wood foam with activated carbon contents of 0%, 10%, 20%, 30%, 40% and 50%; (b) is the desalination evaporation rate of activated carbon wood foam with activated carbon contents of 0%, 10%, 20%, 30%, 40% and 50%;

Figure 4: Wood foam interface temperature diagram, water temperature diagram, indoor evaporation mass loss diagram and evaporation rate diagram under different insulation conditions;

Figure 5: Physical pictures of activated carbon wood foam with sodium chloride content of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%;

Figure 6: Indoor evaporation mass loss diagram and evaporation rate diagram of activated carbon/wood foam with different sodium chloride contents; (a) is the mass loss diagram of activated carbon wood foam with sodium chloride contents of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%; (b) is the desalination evaporation rate of activated carbon wood foam with activated carbon contents of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%;

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Implementation case 1:

The preparation method of activated carbon wood foam is as follows:

Raw material grinding: The raw material used in the present invention is 10 g of wood powder, which is poured into 200 ml of clean water for heating and stirring, and then subjected to mechanical high-pressure homogenization again, so that the diameter of the wood particles is close to the nanometer level.

Mixing and stirring: Pour 200 ml of 5wt% activated carbon solution and 100 ml of 5wt% sodium chloride solution into the wood suspension, stir at room temperature for 1-2 hours, then ultrasonically break the suspension and continue stirring for 1-2 hours to turn the wood into black.

(3) Foam molding: Pour the suspension prepared in (2) into an open acrylic box of 10 cm × 10 cm × 5 cm (length × width × height), freeze it by adjusting the temperature gradient, and freeze it at -40 ° C for more than 6 hours; then freeze-dry it with liquid nitrogen for more than 48 hours, or freeze-dry it in a freezer. The prepared activated carbon wood foam has a 3D structure of a cuboid and contains capillary channel patterns inside.

(4) Indoor solar desalination treatment: The activated carbon wood foam prepared in (3) is placed in the wastewater, the entire device is placed in a water tank, and an LED lamp is used as a light source to perform indoor solar desalination treatment.

Implementation Case 2:

The difference between this implementation case and implementation case 1 lies in step (4).

The water tank in Implementation Case 1 did not take insulation measures. In this implementation case, the activated carbon wood foam prepared was placed in the wastewater, and the entire device was placed in an insulated water tank. LED lights were used as light sources to form an experimental sequence with the water tank insulation conditions as variables, and indoor solar desalination treatment experiments were carried out.

Implementation case three:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of activated carbon solution to wood suspension is 1:10, the solid content of wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with activated carbon mass as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 4:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of activated carbon solution to wood suspension is 1:5, the solid content of wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with activated carbon mass as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 5:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of activated carbon solution to wood suspension is 1:3, the solid content of wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with activated carbon mass as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 6:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of activated carbon solution to wood suspension is 1:2.5, the solid content of wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with activated carbon mass as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 7:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of activated carbon solution to wood suspension is 1:2, the solid content of wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with activated carbon mass as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 8:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:200, the water tank is insulated, the foam height is 1 cm, and the rest of the preparation plan remains unchanged. An experimental sequence with the mass of sodium chloride as a variable is constructed to conduct indoor solar desalination treatment experiments.

Implementation Case 9:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:66, the water tank is insulated, the foam height is 1 cm, and the rest of the preparation plan remains unchanged. An experimental sequence with the mass of sodium chloride as a variable is constructed to conduct indoor solar desalination treatment experiments.

Implementation Case 10:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:49, the water tank is insulated, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with the mass of sodium chloride as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 11:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:39, the water tank is insulated, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with the mass of sodium chloride as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 12:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:33, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged. An experimental sequence with the mass of sodium chloride as a variable is constructed to conduct indoor solar desalination treatment experiments.

Implementation Case Thirteen:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:28, the water tank is insulated, the foam height is 1 cm, and the rest of the preparation plan remains unchanged. An experimental sequence with the mass of sodium chloride as a variable is constructed to conduct indoor solar desalination treatment experiments.

Implementation Case 14:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:24, the water tank is insulated, the foam height is 1 cm, and the rest of the preparation plan remains unchanged. An experimental sequence with the mass of sodium chloride as a variable is constructed to conduct indoor solar desalination treatment experiments.

Implementation Case 15:

The difference between this implementation case and implementation case 1 lies in step (2).

The mass of sodium chloride in Implementation Case 1 accounts for 1% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride solution to activated carbon/wood mixed solution is 1:21, the water tank is insulated, the foam height is 1 cm, and the rest of the preparation plan remains unchanged. An experimental sequence with the mass of sodium chloride as a variable is constructed to conduct indoor solar desalination treatment experiments.

Implementation Case 16:

The difference between this implementation case and implementation case 1 lies in step (4).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride to distilled water is 1:32, the solid content of the wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with wastewater salinity as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 17:

The difference between this implementation case and implementation case 1 lies in step (4).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride to distilled water is 1:10, the solid content of the wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with wastewater salinity as a variable, and conducting indoor solar desalination treatment experiments.

Implementation Case 18:

The difference between this implementation case and implementation case 1 lies in step (4).

The mass of activated carbon in Implementation Case 1 accounts for 50% of the mass of the activated carbon/wood mixture. In this implementation case, the ratio of sodium chloride to distilled water is 1:17, the solid content of the wood is kept unchanged at 5.4%, the water tank is kept warm, the foam height is 1 cm, and the rest of the preparation plan remains unchanged, forming an experimental sequence with wastewater salinity as a variable, and conducting indoor solar desalination treatment experiments.

As can be seen from Figure 1, the activated carbon in the activated carbon wood foam prepared by Example 1 does not destroy the structure of the wood itself. After evaporation and desalination, its composition structure has not changed. It can be seen that the preparation method of this patent is simple and will not cause secondary pollution to the environment.

Figure 2 shows actual pictures of activated carbon wood foams with activated carbon mass accounting for 0%, 10%, 20%, 30%, 40% and 50% of the mass of the activated carbon/wood mixture. It can be seen from the figure that the activated carbon wood foam has an obvious capillary structure and capillary pores, which provide a good pathway for the transport of water; and the wood foam is gray-black after mixing, among which the foam color is the darkest when the activated carbon content is 50%, and the foam color is the lightest when the activated carbon content is 10%. It can be seen that different activated carbon contents can affect the depth of the foam color.

Figure 4 (a, c) shows the interface temperature diagram of wood foam with 50% activated carbon content under different insulation conditions and the water temperature diagram of the solar water evaporation pool. It can be seen from the figure that the interface temperature and water temperature are significantly improved under the insulation conditions, which is beneficial to solar desalination treatment; Figure 4 (b, d) shows the indoor evaporation mass loss diagram and evaporation rate diagram of wood foam with 50% activated carbon content under different insulation conditions. It can be seen from the figure that the evaporation rate is fastest under the insulation conditions.

As can be seen from Figure 3, the color of the activated carbon wood foam deepens after it comes into contact with water, and it becomes jet black, indicating that the foam is hydrophilic and can transport water. The color of the activated carbon foam deepens after absorbing water, which can improve the absorption of light, enhance the photothermal conversion effect, and promote the rapid evaporation of water. When the activated carbon content accounts for 50% of the wood content, the activated carbon wood foam evaporates the fastest, and when the activated carbon content is 30%, the evaporation rate is the slowest. The evaporation rates of activated carbon wood foams with other contents are between the two.

Figure 5 shows actual pictures of activated carbon wood foam when the mass of sodium chloride accounts for 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0% of the mass of the activated carbon/wood mixture, respectively. It can be seen from the figure that the activated carbon wood foam has a significant capillary structure and capillary pores, which provide a good pathway for the transport of water.

As can be seen from Figure 6, the activated carbon wood foam has an obvious capillary structure, which provides a good channel for the transport of water. And after mixing, there are different degrees of white salt attached to the surface of the wood foam, which shows that different NaCl contents can affect the salt attachment on the foam surface. When the NaCl content accounts for 4.5% of the activated carbon/wood content, the activated carbon wood foam evaporates the fastest, and when the NaCl content accounts for 0.0% of the activated carbon/wood content, the evaporation rate is the slowest. The evaporation rates of activated carbon wood foams with other contents are between the two.

In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation 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.

The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims (9)

1. A method for preparing activated carbon wood fiber foam, characterized in that the preparation method comprises the following steps: The wood material is ground to obtain wood powder, and water is added to the wood powder to obtain a wood suspension; a sodium chloride solution is added to the wood suspension to assist in forming with salt ions, and then stirred to obtain a mixed solution 1; an activated carbon solution is added to the mixed solution 1, and stirred to change the mixed solution 1 into a black mixed solution 2; the mixed solution 2 is subjected to ultrasonic crushing to break the fibers in the mixed solution 2, and finally the mixed solution 2 is freeze-dried to obtain an activated carbon wood foam; Wherein: the ratio of wood powder to water is 1g:20ml, the concentration of the sodium chloride solution is 5wt%, and the volume is 100mL; the concentration of the activated carbon solution is 5wt%, and the volume is 200mL. 2. The method for preparing an activated carbon wood fiber foam according to claim 1, characterized in that the wood material is forest waste. 3. The method for preparing an activated carbon wood fiber foam according to claim 1, characterized in that the particle size of the wood powder is less than 200 meshes. 4. The method for preparing an activated carbon wood fiber foam according to claim 1 is characterized in that after adding sodium chloride to the suspension, stirring is carried out, and the stirring conditions are: temperature of 20°C, stirring for 1-2h, and a rotation speed of 300r/min. 5. The method for preparing an activated carbon wood fiber foam according to claim 1, characterized in that the activated carbon solution is prepared by mixing activated carbon and distilled water, wherein the activated carbon is powdered activated carbon, and the activated carbon particle size is less than 200 meshes. 6. The method for preparing an activated carbon wood fiber foam according to claim 1 is characterized in that an activated carbon solution is added to the mixed solution 1 and stirred, and the stirring conditions are: temperature of 20°C, stirring for 1-2 hours, and a rotation speed of 300r/min. 7. The method for preparing activated carbon wood fiber foam according to claim 1 is characterized in that an ultrasonic cell disruptor is used for the ultrasonic disruption, the power ratio of the ultrasonic cell disruptor is set to 20% during use, and the ultrasonic disruption time is 10 minutes. 8. The method for preparing an activated carbon wood fiber foam according to claim 1 is characterized in that the freeze-drying step comprises: freezing the mixed solution 2 at -40°C for 6 hours to freeze-form the mixed solution 2, and then freeze-drying the formed mixed solution 2 under vacuum conditions for 48 hours to sublime the water. 9. An activated carbon wood fiber foam prepared by the preparation method of claims 1-8.