Preparation method of bagasse / geopolymer composite carbonized film for water purification technology

Abstract

The invention belongs to the field of water purification and water recovery, and particularly relates to a biological geopolymer carbonized membrane which is prepared from bagasse powder and a geopolymer, and the biological geopolymer carbonized membrane comprises the following components in percentage by mass: 0.5-3% of bagasse, 0.1-2% of hydrogen peroxide, 0.01-0.06% of lauryl sodium sulfate, 20-27% of slag and the balance of water. The content of the metakaolin is 20%-27%, and the content of the water glass is 41%-46%. The invention also discloses a preparation method of the biological geopolymer diaphragm, which comprises the following specific steps: adding bagasse powder into a geopolymer raw material, uniformly mixing, curing at constant temperature, demolding, grinding and calcining to obtain the bagasse / geopolymer composite carbonized diaphragm. The invention also discloses an application of the biological polymer carbonized membrane in Congo red sewage and seawater desalination. The biological texture polymer carbonized membrane has the capacity of efficiently removing Congo red dye liquor and the capacity of interface evaporation, and application of the biological texture polymer carbonized membrane in multiple fields is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of membrane materials and green chemical industry, and particularly relates to a sugarcane bagasse / geopolymer composite carbonized membrane for treating Congo red dye liquor wastewater and desalinating seawater as well as a preparation method and application thereof. BACKGROUND

[0002] The rapid industrialization process has led to an increasing demand for dyes in the textile papermaking, food, medicine and cosmetic industries, and the discharge of a large amount of dye liquor wastewater has caused water pollution and further shortage of freshwater resources. Congo red is a dye widely used in the textile industry, which poses a significant threat to organisms due to its carcinogenicity and non-biodegradability. The global printing and dyeing industry discharges more than 120 million tons of wastewater containing Congo red dye liquor every year, 20-60% of which is directly discharged without effective treatment. As a typical high-toxicity anionic azo dye, Congo red is difficult to be quickly eliminated in the natural environment through microbial decomposition or photodegradation due to the stable azo bond (-N=N-) and aromatic ring structure in its molecular structure, and is therefore classified as a persistent organic pollutant, which cannot be effectively removed by traditional wastewater treatment processes. The accumulation of industrial solid waste and fly ash will deteriorate air quality and even cause haze, affecting human health, and the accumulation of agricultural waste will rot under microbial degradation to produce toxic substances and pungent odors, and a large amount of incineration will produce carbon dioxide and dust, polluting the environment. The increasing population and accelerated industrialization process have exacerbated the greenhouse effect, accelerated the melting of glaciers, thermal expansion of seawater, changes in ocean circulation and aggravated water pollution. Climate change has also exacerbated extreme weather conditions such as droughts and floods, further exacerbating water shortages. The development of traditional water sources has reached its limit, so developing desalination technology to obtain freshwater from the ocean is an important way to solve water shortages.

[0003] At present, many materials in the field of water treatment can only be used in a single field of water pollution or water desalination. Traditional single-function water treatment technologies are difficult to meet the demand of water treatment in multiple fields. In recent years, the strategy of using membrane separation for treatment or obtaining freshwater resources through interfacial evaporation has begun to appear in the field of water treatment and seawater desalination, and has become a research hotspot for researchers due to its simplicity, easy recovery and avoidance of secondary pollution. Therefore, it is of great application significance to study and prepare a multi-field membrane material that can be used for Congo red removal and desalination.

[0004] Therefore, it is an urgent need to treat dye liquor pollution in water bodies and obtain freshwater resources. The present application uses solid waste and agricultural waste as raw materials to develop a membrane material that not only solves the pollution problem caused by the accumulation of industrial solid waste and agricultural waste, but also solves the problems of water pollution caused by Congo red dye liquor and the acquisition of freshwater resources through seawater desalination. SUMMARY

[0005] The technical problems solved by the present application are to provide a biomass / geopolymer carbonized membrane, which solves the problems of water pollution caused by Congo red dye and seawater desalination to obtain fresh water resources.

[0006] The technical scheme is a preparation method of a bagasse / geopolymer composite carbonized membrane for water purification technology, which is characterized by being composed of bagasse, slag and metakaolin, and obtaining a bagasse / geopolymer composite membrane through alkali activation; and then forming a bagasse / geopolymer composite carbonized membrane through inert gas calcination. The preparation steps are as follows: (1) uniformly mixing the bagasse, metakaolin, slag and water glass, and stirring the mixture at room temperature by using a dispersing machine at a high speed; (2) adding hydrogen peroxide and sodium dodecyl sulfate into the mixed slurry and continuing to stir at a high speed, after the stirring is completed, the slurry is poured into a mold and is cured in a constant temperature oven; (3) taking out the bagasse / geopolymer composite membrane after the curing is completed, and demolding and polishing the membrane to make the thickness of the membrane appropriate; (4) placing the membrane in a small crucible, and placing the crucible into a tube furnace, and introducing inert gas, and setting the calcination temperature and calcination time, and after the calcination is completed, the bagasse / geopolymer composite carbonized membrane is obtained, and a membrane preparation flow chart is shown in Figure 2 , and a membrane morphology is shown in Figure 3 .

[0008] Preferably, in the step (1), the bagasse powder needs to pass through a 100-200 mesh sieve and is added in an amount of 1-7 g, the metakaolin is added in an amount of 40-50 g, the slag is added in an amount of 40-50 g, the water glass modulus is 1.3-1.5 M and is added in an amount of 80-90 g, and the high-speed dispersing machine rotates at a speed of 800-1200 r / min, and the stirring time is 1-5 min.

[0009] Preferably, in the step (2), the 30% hydrogen peroxide is added in an amount of 1.5-2.0 g, the sodium dodecyl sulfate is added in an amount of 0.05-0.1 g, the high-speed dispersing machine rotates at a speed of 800-1200 r / min, the stirring time is 1-5 min, the curing temperature is 60-80 ℃, and the time is 20-24 h.

[0010] Preferably, in the step (3), the thickness of the bagasse / geopolymer composite membrane is 2.0-5.0 mm.

[0011] Preferably, in the step (4), the inert gas is nitrogen, the tube furnace has a temperature rising rate of 1-4 min / ℃, the calcination temperature is 500-800 ℃, and the time is 10-80 min.

[0012] The bagasse / geopolymer composite carbonized membrane prepared by the above preparation method.

[0013] The bagasse / geopolymer composite carbonized membrane described above is characterized by being composed of bagasse, metakaolin, slag and water glass, and forming a bagasse / geopolymer composite carbonized membrane.

[0014] The bagasse / geopolymer composite carbonized membrane has excellent interception performance in water bodies containing Congo red dye solution, and has excellent interfacial evaporation effect in seawater desalination application, thereby providing a specific solution to water pollution and water resource shortage.

[0015] Advantages: (1) low raw material cost; (2) using industrial solid waste and agricultural waste as raw materials to solve the accumulation and pollution of solid waste and agricultural waste; (3) the bagasse / geopolymer composite carbonized membrane has low preparation cost, mild conditions and simple operation; (4) the bagasse / geopolymer composite carbonized membrane is easy to recycle and does not easily cause secondary pollution; (5) the bagasse / geopolymer composite carbonized membrane provided by the present application is a dual-functional material for removing Congo red and realizing seawater desalination. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 XRD pattern of the bagasse / geopolymer composite carbonized membrane prepared in Example 1 of the present application.

[0017] Figure 2 Preparation flow chart of the bagasse / geopolymer composite carbonized membrane

[0018] Figure 3 Pictures of the bagasse / geopolymer composite carbonized membrane (a. front view of the membrane; b. optical microscope surface view; c, d. electron microscope view of the membrane).

[0019] Figure 4 Congo red removal performance chart of the geopolymer membrane in Comparative Example 1, the bagasse carbon in Comparative Example 2 and the bagasse / geopolymer composite carbonized membrane in Example 1 for different concentrations of Congo red.

[0020] Figure 5 Simulated sunlight evaporation test equipment

[0021] Figure 6 Light and dark comparison chart of pure water and simulated seawater with the membrane and the geopolymer membrane in Comparative Example 1 and the bagasse / geopolymer composite carbonized membrane in Example 2 DETAILED DESCRIPTION

[0022] In order to better illustrate the present application and facilitate understanding of the technical solutions of the present application, the typical but non-limiting embodiments of the present application are as follows:

[0023] Example 1

[0024] A preparation method of a sugarcane bagasse / geomemrane composite carbonized membrane (PGM@BC) for intercepting Congo red dye solution, the specific steps are: (1) mix 3g of sugarcane bagasse, 50g of metakaolin, 50g of slag and 85g of 1.3M water glass uniformly, and stir the mixture at a speed of 1000r / min for 3min at room temperature by using a disperser; (2) add 30% hydrogen peroxide 1.86g and sodium dodecyl sulfate 0.08g, continue to stir at high speed for 1min, after stirring, perform slurry mold turning and curing in a constant temperature oven at 60℃ for 24h; (3) take out the cured sugarcane bagasse / geomemrane composite membrane, demold and polish to make the membrane thickness 3.5mm; (4) place the membrane in a small crucible, put it into a tube furnace, pass nitrogen gas, set the heating rate to 3℃ / min, the calcination temperature to 750℃, and the calcination time to 30min, after calcination, naturally cool down to obtain the sugarcane bagasse / geomemrane composite carbonized membrane.

[0025] Example 2

[0026] A preparation method of a sugarcane bagasse / geomemrane composite carbonized membrane for seawater desalination by interfacial evaporation technology, the specific steps are: (1) mix 5g of sugarcane bagasse, 50g of metakaolin, 50g of slag and 85g of 1.3M water glass uniformly, and stir the mixture at a speed of 1000r / min for 3min at room temperature by using a disperser; (2) add 30% hydrogen peroxide 1.86g and sodium dodecyl sulfate 0.08g, continue to stir at high speed for 1min, after stirring, perform slurry mold turning and curing in a constant temperature oven at 60℃ for 24h; (3) take out the cured sugarcane bagasse / geomemrane composite membrane, demold and polish to make the membrane thickness 3.0mm; (4) place the membrane in a small crucible, put it into a tube furnace, pass nitrogen gas, set the heating rate to 3℃ / min, the calcination temperature to 600℃, and the calcination time to 30min, after calcination, naturally cool down to obtain the sugarcane bagasse / geomemrane composite carbonized membrane.

[0027] Comparative Example 1

[0028] A preparation method of a geomemrane membrane (PGM) for intercepting Congo red dye solution, the specific steps are: (1) mix 0g of sugarcane bagasse, 50g of metakaolin, 50g of slag and 85g of 1.3M water glass uniformly, and stir the mixture at a speed of 1000r / min for 3min at room temperature by using a disperser; (2) add 30% hydrogen peroxide 1.86g and sodium dodecyl sulfate 0.08g, continue to stir at high speed for 1min, after stirring, perform slurry mold turning and curing in a constant temperature oven at 60℃ for 24h; (3) take out the cured sugarcane bagasse / geomemrane composite membrane, demold and polish to make the membrane thickness 3.0mm.

[0029] Comparative Example 2

[0030] A preparation method of a bagasse carbon for intercepting Congo red dye solution, and the specific steps are as follows: (1) placing bagasse in a small crucible, putting into a tube furnace, passing nitrogen, setting the heating rate as 3 ℃ / min, the calcination temperature as 750 ℃, and the calcination time as 30 min, and after the calcination is completed, cooling to obtain the bagasse carbon.

[0031] Example 3

[0032] In the experiment, 5-25 mg / L of Congo red dye solution is selected as the treatment solution. The specific steps are as follows: taking the Congo red removal materials prepared by the preparation methods of example 1, comparative example 1 and comparative example 2 (according to the mass fraction of bagasse in the carbonized film) respectively. The preparation materials of example 1, comparative example 1 and comparative example 2 are used to intercept and adsorb the Congo red dye solution with concentrations of 5, 10, 15, 20 and 25 mg / L for 1 h at room temperature. After the experiment is completed, the ultraviolet spectrophotometer is used for detection, and the calculation and drawing are performed through formulas (1-1 and 1-2), as shown in Figure 4 .

[0033]

[0035] From Figure 4 It can be seen that there is a huge difference in the Congo red dye removal performance of the bagasse / geopolymer composite carbonized film in example 1, the simple geopolymer film in comparative example 1 and the simple bagasse carbon in comparative example 2. As can be seen from the figure, although the bagasse / geopolymer composite carbonized film is composed of bagasse and geopolymer, the removal performance in the figure shows that it is much better than the performance of the two single substances added together.

[0036] From Figure 4 It can be seen that the bagasse / geopolymer composite carbonized film prepared by the bagasse and the geopolymer has excellent Congo red dye removal performance, and the single bagasse carbon and the geopolymer have low removal rates when used for treating Congo red. As can be seen from the data of the geopolymer film (PGM) in comparative example 1, the removal rate is much lower than 20% in the concentration range of 5-25 mg / L of Congo red dye solution; the removal rate of the bagasse carbon in comparative example 2 is about 50% in the concentration range of 5-25 mg / L of Congo red dye solution; and the removal rate of the bagasse / geopolymer composite carbonized film in example 1 is about 80% in the concentration range of 5-25 mg / L of Congo red dye solution; which is higher than the sum of the removal rates of comparative example 1 and comparative example 2, indicating that the bagasse / geopolymer composite carbonized film has excellent Congo red dye removal performance.

[0037] Example 4

[0038] The experiment uses a xenon lamp with a 1.5G filter to simulate sunlight, and realizes seawater desalination through interfacial evaporation technology. The simulation test equipment is as shown in Figure 5 . The specific steps are as follows: (1) In a dark environment, without a film, 100g of deionized water and 100g of simulated seawater of sodium chloride are respectively dark evaporated for 5h, the mass loss is detected in real time by using computer software, and the light evaporation rate and solar energy conversion efficiency are calculated by using formula (2-1, 2-2); (2) In the xenon lamp simulated sunlight environment, without a film, 100g of deionized water and 100g of simulated seawater of sodium chloride are respectively light evaporated for 5h, the mass loss is detected in real time by using computer software, and the light evaporation rate and solar energy conversion efficiency are calculated by using formula (2-1, 2-2); (3) In the xenon lamp simulated sunlight environment, with the PGM of the comparative example 1, 100g of deionized water and 100g of simulated seawater of sodium chloride are respectively light evaporated for 5h, the mass loss is detected in real time by using computer software, and the light evaporation rate and solar energy conversion efficiency are calculated by using formula (2-1, 2-2); (4) In the xenon lamp simulated sunlight environment, with the PGM@BC of the example 2, 100g of deionized water and 100g of simulated seawater of sodium chloride are respectively light evaporated for 5h, the mass loss is detected in real time by using computer software, and the light evaporation rate and solar energy conversion efficiency are calculated by using formula (2-1, 2-2). The above data are plotted to obtain Figure 6 .

[0039]

[0041] From Figure 6 , it can be seen that the interfacial evaporation performance of the PGM@BC of the example 2 and the PGM of the comparative example 1 has a great difference. From Figure 4 , it can be understood that whether it is deionized water or simulated seawater, the solar light evaporation performance of the PGM@BC of the example 2 is better than that of the PGM of the comparative example 1, especially when the simulated seawater is interfacially evaporated. The PGM@BC has excellent solar energy conversion efficiency (122.17%), and the light evaporation rates of the deionized water and the simulated seawater are 2.22kg.m -2 .h -1 , 1.90kg.m -2 .h -1 , which are 3.2 times and 3.06 times of the light evaporation rates of the deionized water and the simulated seawater without a film, respectively. It shows that the PGM@BC has excellent interfacial evaporation performance for seawater desalination.

[0042] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a bagasse / geopolymer composite carbonized membrane for water purification technology, characterized in that, Composed of bagasse, slag and metakaolin, a bagasse / geopolymer composite membrane is obtained by alkaline activation; then, a bagasse / geopolymer composite carbonized membrane is formed by inert gas calcination. The preparation steps are as follows: (1) Mix bagasse, metakaolin, slag and water glass, and stir the mixture at high speed for 1-5 min at room temperature using a disperser; (2) Add hydrogen peroxide and sodium dodecyl sulfate to the mixed slurry and continue stirring at high speed for 1-5 min. After stirring, the slurry is poured into a mold and cured in a constant temperature oven; (3) Take out the cured bagasse / geopolymer composite membrane, demold it and polish it to make the membrane thickness suitable; (4) Place the membrane in a small crucible, put it in a tube furnace, introduce inert gas and set the calcination temperature and calcination time. After calcination, the bagasse / geopolymer composite carbonized membrane can be obtained.

2. The method for preparing the biomass / geopolymer carbonized film according to claim 1, characterized in that, In step (1), the bagasse powder needs to be passed through a 100-200 mesh sieve and 1-7g is added, metakaolin is added 40-50g, slag is added 40-50g, water glass modulus is 1.3-1.5M and 80-90g is added, and the speed of the high-speed disperser is 800-1200r / min.

3. The method for preparing the biomass / geopolymer carbonized film according to claim 2, characterized in that, In step (2), 1.5-2.0g of 30% hydrogen peroxide and 0.05-0.1g of sodium dodecyl sulfate are added. The speed of the high-speed disperser is 800-1200r / min, the curing temperature is 60-80℃, and the curing time is 20-24h.

4. The method for preparing the biomass / geopolymer carbonized film according to claim 3, characterized in that, In step (3), the thickness of the bagasse / geopolymer composite film is 2.0-5.0 mm.

5. The method for preparing the biomass / geopolymer carbonized film according to claim 4, characterized in that, In step (4), the inert gas is nitrogen, the calcination temperature in the tubular furnace is 500-800℃, and the time is 10-80min.

6. The bagasse / geopolymer composite carbonized film prepared by any of the preparation methods described in claims 1-4.

7. The bagasse / geopolymer composite carbonization membrane according to claim 6, characterized in that, Composed of bagasse, metakaolin, slag and water glass, it forms a bagasse / geopolymer composite carbonized film.

8. The application of the bagasse / geopolymer composite carbonization membrane according to claim 7 in the removal of Congo red dye water pollution and seawater desalination.

9. The application of the bagasse / geopolymer composite carbonized membrane according to claim 8 in the removal of Congo red dyeing solution pollution, characterized in that, The concentration of Congo red staining solution was 5-30 mg / L, the retention time was 0.5-2.5 h, and the reaction temperature was room temperature.

10. The application of the bagasse / geopolymer composite carbonization membrane according to claim 9 in seawater desalination, characterized in that, The simulated seawater concentration was 0-15.0 wt%, and the light intensity was 0-3.0 kW / m². 2 The wind speed is 0-5.0 m / s.

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