Incinerator ash activated carbon composite hollow fiber and method for producing the same

Abstract

This invention provides incineration ash activated carbon composite hollow fibers and a method for producing the same. [Solution] The method includes selecting incinerated bottom ash in which the calcium content is greater than the silicon content in its elemental composition; mixing the selected incinerated bottom ash with activated carbon material, an organic solvent, and a polymer to form a spinning solution; spinning the spinning solution using a wet-dry spinning method in a spinning apparatus to form a hollow fiber precursor; and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form a composite hollow fiber made of incinerated bottom ash and activated carbon material. The weight ratio of incinerated bottom ash to activated carbon material (incinerated bottom ash: activated carbon material) is 5:1 to 15:1. Specific surface area S of the composite hollow fiber made of incinerated bottom ash and activated carbon material. BET is 0.3m 2 / g~0.9m 2 / g is the average pore size D of the micropores. p The wavelength range is 650 nm to 1,150 nm, and the zero charge point is 10.5 to 11.5.

Description

[Technical Field]

[0001] The present invention relates to hollow fibers, and more particularly to incineration ash activated carbon composite hollow fibers and a method for producing the same. [Background technology]

[0002] Human life generates a large amount of waste every day, and statistics show that Taiwan needs to process several thousand tons of waste daily. Incineration of this waste produces a large amount of incinerated ash. Traditionally, this ash has been used primarily as a building material, such as mixed with cement or tiles to make sidewalks. However, due to regional constraints (such as areas designated for soil and water quality conservation), the reuse of this incinerated ash is limited, and some of it must be disposed of through landfill or other means, increasing the environmental burden.

[0003] Furthermore, the composition of incinerated ash is complex, containing various metallic and non-metallic elements such as silicon, aluminum, calcium, iron, and magnesium. In the past, techniques have been used to extract valuable metals such as aluminum and silicon from incinerated ash, but these methods usually only recover a portion of the metal, leaving a large amount of waste after extraction, and failing to completely solve the problem of incinerated ash treatment. It is also known from conventional technology that activated carbon materials can be used to adsorb impurities, but after use in an aqueous phase environment, separation and recovery are unfavorable. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] This invention primarily aims to improve upon the problems present in existing technologies, explore novel recycling methods and application methods for incineration bottom ash, and provide incineration bottom ash-activated carbon composite hollow fibers and a method for producing the same. [Means for solving the problem]

[0005] One embodiment of the present invention provides a method for producing composite hollow fibers made of activated carbon from incinerated ash. The method for producing composite hollow fibers made of activated carbon from incinerated ash includes: a selection process, which includes selecting incinerated ash in which the content of calcium in its elemental composition is greater than the content of silicon; a spinning solution production process, which includes mixing the selected incinerated ash with an activated carbon material, an organic solvent, and a polymer to form a spinning solution, wherein the weight ratio of the incinerated ash to the activated carbon material (incinerated ash:activated carbon material) is 5:1 to 15:1; and a hollow fiber production process, which includes spinning the spinning solution in a spinning apparatus using a wet-dry spinning method to form a hollow fiber precursor, and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form a composite hollow fiber made of the incinerated ash and the activated carbon material.

[0006] Another embodiment of the present invention provides a composite hollow fiber of incinerator ash activated carbon produced by the above method. The elemental composition of the composite hollow fiber of incinerator ash activated carbon contains more calcium than silicon, and the specific surface area S of the composite hollow fiber of incinerator ash activated carbon has BET is 0.3m 2 / g~0.9m 2 / g is the average pore size D of the micropores. p The wavelength range is 650 nm to 1,150 nm, and the zero charge point is 10.5 to 11.5. [Effects of the Invention]

[0007] As described above, the method for producing incinerator bottom ash activated carbon composite hollow fibers according to the present invention makes it possible to produce incinerator bottom ash as hollow fibers with relatively high economic value, and these hollow fibers are particularly suitable for wastewater treatment, such as adsorption of organic impurities. [Brief explanation of the drawing]

[0008] [Figure 1] This is a flowchart of a method for manufacturing composite hollow fibers according to an embodiment of the present invention. [Figure 2]This is a spectral diagram obtained by analyzing the incinerated bottom ash selected according to an embodiment of the present invention using scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS). [Figure 3] This is a schematic diagram of a spinning apparatus according to an embodiment of the present invention. [Figure 4] This is a schematic diagram of a composite hollow fiber according to an embodiment of the present invention. [Figure 5A] This is a scanning electron microscope (SEM) image (magnification 50x) of a cross-section of an incineration ash activated carbon composite hollow fiber according to an embodiment of the present invention. [Figure 5B] This is a scanning electron microscope (SEM) image (magnification 150x) of a cross-section of a hollow fiber composite made of activated carbon from incinerated ash according to an embodiment of the present invention. [Figure 6] This shows the Fourier transform infrared spectroscopy (FTIR) analysis results of composite hollow fiber (BAACHF) and activated carbon material (AC) according to an embodiment of the present invention. [Figure 7] These are the test results of dye adsorption and COD removal efficiency of composite hollow fibers according to embodiments of the present invention at different contact times with test solutions. [Figure 8] These are the test results of dye adsorption and COD removal efficiency at different initial MyB dye concentrations for composite hollow fibers according to embodiments of the present invention. [Figure 9] This is an analysis of the zero charge point (pH_pzc) of a composite hollow fiber according to an embodiment of the present invention. [Modes for carrying out the invention]

[0009] To better understand the features and technical content of the present invention, the following detailed description and drawings of the present invention will be referenced; however, the provided description and drawings are for reference and illustrative purposes only and do not limit the present invention.

[0010] In the following explanations, when there are phrases such as "consider specific drawings" or "as shown in specific drawings," these are merely to emphasize that the content of the subsequent explanations is generally described in those specific drawings, and other drawings may also be consulted.

[0011] It should be understood that in this specification, various materials or properties may be described using terms such as "first", "second", "third", etc., but these materials or properties are not limited by these terms. These terms are mainly used to distinguish one material from another or one property from another. Also, the term "or" used in this specification may include any one or a combination of one or more of the items listed in relation according to the actual situation.

[0012] It should be noted that in this specification, when the numerical range of a parameter is described as being between one numerical value and another numerical value, it should be understood that both end values are included in that numerical range. In other words, unless explicitly stated or when a different meaning can be inferred from the context, the numerical range includes the one value described and the other value described. This explanation aims to clarify the scope of the technology and avoid unnecessary restrictions due to different interpretations.

[0013] [Method for manufacturing composite hollow fibers with incineration bottom ash and activated carbon] As shown in FIG. 1, in an embodiment of the present invention, a method for manufacturing composite hollow fibers (bottom ash activated carbon hollow fiber, BAACHF) including step S110, step S120, step S130, and step S140 is provided. It should be noted that the order and actual operation method of each step in this embodiment can be adjusted as needed and are not limited thereto.

[0014] Step S110 is a sorting operation including finding the source of incineration bottom ash and sorting out incineration ash in which the content of calcium element in the elemental composition is greater than the content of silicon element. Here, the incineration bottom ash is generated after incinerating garbage.

[0015] In one embodiment of the present invention, the elemental composition of the selected incinerated bottom ash must satisfy the following conditions as a result of scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) analysis: (1) the weight percentage concentration of calcium element is 15 wt% or more, preferably 20 wt% or more, and particularly preferably 25 wt% or more; and (2) the weight ratio of the weight percentage concentration of calcium element (calcium (Ca) / silicon (Si)) to the weight percentage concentration of silicon element is 2 or more, preferably 4 or more, and particularly preferably 8 or more. The analytical parameters for the scanning electron microscope are as follows: a scanning electron microscope (SEM: Hitachi S-3400N) is used, the electron gun is a tungsten filament, and the acceleration voltage is 15.0 kV. The SEM-EDS analysis method may be based on, for example, ASTM E1508-12a, but is not limited thereto.

[0016] Furthermore, the elemental composition of the incinerated bottom ash also includes other trace metal elements such as aluminum, sodium, magnesium, molybdenum, or iron, and the weight percentage concentration of the calcium element is higher than the weight percentage concentration of any of the other trace metal elements, but the present invention is not limited thereto.

[0017] In one embodiment of the present invention, the weight percentage concentration of calcium element in the selected incinerated bottom ash is 25 wt% to 40 wt% (e.g., 30 to 33 wt%), the weight percentage concentration of silicon element is 1 wt% to 10 wt% (e.g., 2 wt% to 3 wt%), and the weight ratio of calcium (Ca) to silicon (Si) (calcium (Ca) / silicon (Si)) is 10 to 15, but the present invention is not limited thereto.

[0018] As shown in Figure 2, Figure 2 is a spectral diagram obtained by scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) analysis of the incineration bottom ash selected in the embodiment of the present invention, and shows characteristic energy peaks of the elements contained in the incineration bottom ash.

[0019] Here, the Ca (calcium) peak is prominent, with a significant Ca energy peak at the high energy end (approximately 3.69 keV), indicating a relatively high calcium content in this incineration ash. Calcium is one of the most characteristic and abundant elements in this incineration ash. Regarding the Si (silicon) peak, an energy peak for Si is observed at approximately 1.74 keV, indicating that the ash contains silicate compounds, but in a lower proportion than calcium. Elements such as Al (aluminum), Na (sodium), Mg (magnesium), and Mo (molybdenum) have relatively small peak values, indicating that their content is relatively low compared to calcium and silicon. The spectrum shows an O (oxygen) peak, which indicates that at least some of the metallic elements exist in oxide form. In the elemental composition of this incineration ash, the weight percentage concentration of calcium is 31.69 wt%, the weight percentage concentration of silicon is 2.57 wt%, and the weight percentage concentration of aluminum is 1.1 wt%.

[0020] Furthermore, the calcium element in the incinerated bottom ash originates from calcium compounds such as calcium oxide (CaO) and calcium hydroxide (Ca(OH)2), the silicon element originates from silicon compounds such as silicon dioxide (SiO2), and the aluminum element originates from aluminum compounds such as aluminum oxide (Al2O3).

[0021] In another embodiment of the present invention, the composition of the selected incinerated bottom ash must satisfy the following conditions as a result of analysis by inductively coupled plasma emission spectrometry (ICP-OES): (1) The weight percentage concentration of calcium compounds (e.g., the total weight percentage concentration of calcium oxide and calcium hydroxide) is 30 wt% or more, preferably 40 wt% or more, and particularly preferably 50 wt% to 75 wt%; and (2) The weight percentage concentration of calcium compounds is 1.2 times or more, preferably 1.5 times or more, and particularly preferably 1.8 times or more, the weight percentage concentration of silicon compounds (e.g., silicon dioxide). An example of an analytical method for an embodiment of the present invention is as follows: The properties of the incinerated bottom ash used are measured by microwave decomposition to determine the metal ion concentration, and the weight of the metal ions is determined by multiplying this by the volume and converting it. The microwave decomposition measurement method is as follows. 1. Place 0.1g of the sample (in this case, incinerated bottom ash) in a 100°C oven and dry for 2 hours. 2. Place 0.1 g of the dried sample into a decomposition bottle, add 9 mL of 70% nitric acid, 3 mL of hydrofluoric acid, and 3 mL of 37% hydrochloric acid, and pre-decompose for 30 minutes. 3. Heat at 180°C for 25 minutes, then keep warm for 10 minutes. 4. After cooling, add 15 mL of boric acid and pre-decompose for 30 minutes. 5. Repeat step 3. 6. The water sample after microwave decomposition is quantified, and the metal ion concentration is analyzed by ICP-OES. 7. ICP-OES model: Inductively coupled plasma-optical emission spectrometry (ICP-OES, Avio 200, PerkinElmer). However, the present invention is not limited thereto.

[0022] Step S120 is a pretreatment operation of incinerated bottom ash, which includes sequentially performing drying (S121), crushing (S122), sieving (S123), and calcination (S124) on the selected incinerated bottom ash. This removes most of the residual moisture and organic matter from the incinerated bottom ash, and yields incinerated bottom ash powder with an average particle size of 60 μm or less, preferably 55 μm or less, and particularly preferably 50 μm or less.

[0023] More specifically, the drying process (S121) includes placing the incinerated ash in a drying apparatus (e.g., an oven) and drying it at a drying temperature of 50°C to 200°C, preferably 130°C to 170°C, to remove most of the moisture remaining in the incinerated ash (for example, reducing the moisture content to 1 wt%, preferably 0.5 wt% or less). The drying duration is, for example, 0.5 hours to 36 hours (e.g., 24 hours) and can be adjusted according to the actual operating requirements.

[0024] The crushing process (S122) involves crushing the dried incinerated bottom ash with a crushing device (such as a crusher) or crushing means (such as a hammer crusher) to crush relatively large particles or lumps in the incinerated bottom ash into relatively small particles or powder.

[0025] The sieving process (S123) includes sieving the crushed incinerated bottom ash with a particle size sorter (for example, with a mesh size of 200 mesh to 1000 mesh) to obtain incinerated bottom ash with an average particle diameter D50 of 60 μm or less, preferably 55 μm or less, and particularly preferably 50 μm or less.

[0026] The calcination treatment (S124) involves placing the sieved incineration bottom ash into a high-temperature device (e.g., a high-temperature furnace) and calcining it at a calcination temperature of 300°C to 800°C, preferably 500°C to 800°C (e.g., 750°C) to remove most of the organic matter remaining in the incineration bottom ash (for example, reducing the organic matter content to 1 wt% or less, preferably 0.5 wt% or less). Here, the calcination duration is, for example, 0.5 hours to 12 hours (e.g., 3 hours) and can be adjusted according to the actual operating requirements.

[0027] It is worth noting that, through the aforementioned pretreatment process for incinerated bottom ash, residual moisture and organic matter can be removed, resulting in finer and more uniform particle size, which facilitates subsequent spinning and hollow fiber manufacturing.

[0028] However, the present invention is not limited to the above embodiments, and in another embodiment of the present invention, the incinerated bottom ash may be used directly in the subsequent production of the spinning solution and hollow fibers without performing the above-mentioned pretreatment work of the incinerated bottom ash.

[0029] Step S130 is a spinning solution manufacturing operation, which includes further mixing the sorted and processed incinerated bottom ash with activated carbon material (AC), an organic solvent, and a polymer to form a spinning solution. Here, the weight ratio of incinerated bottom ash to activated carbon material (incinerated bottom ash:activated carbon material) is 5:1 to 15:1, preferably 7:1 to 12:1, and particularly preferably 8:1 to 10:1, but the present invention is not limited thereto. Furthermore, as the activated carbon material, for example, powdered activated carbon (PAC) is used to facilitate mixing with incinerated bottom ash. More specifically, in one embodiment of the present invention, the activated carbon powder (AC) used is flake-shaped or fragment-shaped particles with an average particle size of about 30 μm to 150 μm and a relatively high specific surface area. According to SEM-EDS analysis, the elemental composition (wt%) of the activated carbon powder includes carbon, oxygen in an amount of approximately 10 wt% to 15 wt%, and trace amounts of titanium (approximately 0.3 wt% to 0.5 wt%). This activated carbon powder is porous and may have modified functional groups (e.g., oxygen-containing functional groups) on its surface, making it advantageous for mixing with incineration bottom ash to form a composite with enhanced adsorption or catalytic properties. However, the selection of the activated carbon material of the present invention is not limited to the above-described embodiment.

[0030] Furthermore, the organic solvent may be at least one selected from the group consisting of, for example, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and dimethyl sulfoxide (DMSO). In one embodiment of the present invention, N-methylpyrrolidone (NMP) is selected as the organic solvent.

[0031] The polymer may be at least one selected from the group consisting of, for example, polyvinylpyrrolidone (PVP), polyethersulfone (PESf), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyetherimide (PEI), polyetheretherketone (PEEK), polyvinyl alcohol (PVA), and polyethylene glycol (PEG).

[0032] In the composition of the spinning solution, the content of incinerated bottom ash is 20 wt% to 60 wt%, preferably 25 wt% to 55 wt%, and particularly preferably 30 wt% to 50 wt%, based on 100 wt% of the total weight of the spinning solution. The content of activated carbon material is 1 wt% to 15 wt%, preferably 1 wt% to 10 wt%, and particularly preferably 2 wt% to 6 wt%, based on 100 wt% of the total weight of the spinning solution.

[0033] The content of the organic solvent is 25 wt% to 60 wt%, preferably 30 wt% to 60 wt%, and particularly preferably 40 wt% to 60 wt%. The content of the polymer is 0.1 wt% to 15 wt%, preferably 0.5 wt% to 10 wt%, and particularly preferably 1 wt% to 8 wt%.

[0034] In one embodiment of the present invention, the polymer comprises both polyvinylpyrrolidone (PVP) and polyethersulfone (PESf), with a polyvinylpyrrolidone (PVP) content of 0.5 wt% to 2 wt% and a polyethersulfone (PESf) content of 4 wt% to 6 wt%, but the present invention is not limited thereto.

[0035] Here, polyvinylpyrrolidone (PVP) is hydrophilic and helps to form a pore structure on the composite hollow fiber (BAACHF), while polyethersulfone (PESf) can be used as an adhesive and helps to adhere the incineration bottom ash and activated carbon material when the composite hollow fiber is spun into yarn.

[0036] According to the above configuration, a hollow fiber spinning solution is obtained that has a moderate viscosity and in which the incinerated bottom ash and activated carbon material are uniformly dispersed, which is advantageous for subsequent spinning and hollow fiber production.

[0037] Furthermore, mixing a small amount of activated carbon material with the incinerated bottom ash is advantageous in increasing the specific surface area of ​​the composite hollow fibers, providing good adsorption performance for impurities and organic pollutants.

[0038] In one embodiment of the present invention, the spinning solution manufacturing process may selectively include grinding the spinning solution with a grinding device to uniformly mix all components in the spinning solution (including incinerated bottom ash, activated carbon material, organic solvent, and high-molecular-weight polymer) and further reducing the particle size of the incinerated bottom ash particles.

[0039] Examples of grinding devices include ball mills, grinding machines, and bead mills. Preferably, a planetary ball mill is used as the grinding device, the orbital speed of the ball mill is, for example, 120 rpm to 240 rpm, preferably 160 rpm to 200 rpm, and the ball mill grinding time is, for example, 3 hours or more, preferably 12 hours or more, but the present invention is not limited thereto.

[0040] More specifically, the spinning solution manufacturing process may involve, for example, mixing incinerated bottom ash, activated carbon material, an organic solvent (such as NMP), and polyvinylpyrrolidone (PVP), then ball-milling the mixture in a planetary ball mill at an orbital speed of 160 rpm to 200 rpm for 12 to 48 hours to form a mixture, followed by adding polyethersulfone (PESf) to the mixture, and then continuously ball-milling the mixture in a planetary ball mill at an orbital speed of 160 rpm to 200 rpm for 12 to 48 hours to form the spinning solution.

[0041] Referring to Figures 3 and 4, step S140 is a hollow fiber manufacturing operation, which involves spinning the spinning solution L1 in a spinning apparatus 100 (such as a spinning machine) using a dry-wet spinning method to form a hollow fiber precursor P' having a hollow structure, and then sintering the hollow fiber precursor P' at a sintering temperature of 1100°C to 1200°C to remove organic solvents and polymer polymers, thereby forming a composite hollow fiber P (BAACHF) mainly composed of incineration bottom ash and activated carbon material.

[0042] Specifically, the spinning nozzle 1 of the spinning apparatus 100 has a coaxial double-tube structure consisting of an outer tube 11 and an inner tube 12. Here, the spinning solution L1 is supplied to the outer tube 11, and the mesoporous solution L2 (for example, deionized water) is supplied to the inner tube 12. After the spinning solution L1 is discharged from the outer tube 11 of the spinning nozzle 1, it undergoes phase separation and solidification in the coagulation bath T to form the outer wall of the hollow fiber precursor P'. After the mesoporous solution L2 is discharged from the inner tube 12 of the spinning nozzle 1, the spinning solution L1 leaves a hollow internal cavity when solidified, and the solidified fiber has a hollow structure. Here, the coagulation bath T may be a liquid component with the same composition as the mesoporous solution, such as deionized water, and the temperature may be room temperature, and the spinning solution L1 undergoes phase separation and solidifies in the coagulation bath T.

[0043] In one embodiment of the present invention, the diameter of the outer tube 11 of the spinning nozzle 1 is 1.5 mm to 4 mm, preferably 2 mm to 3 mm. The diameter of the inner tube 12 of the spinning nozzle 1 is 0.8 mm to 1.35 mm, preferably 0.9 mm to 1.3 mm. The difference between the diameter of the outer tube 11 and the diameter of the inner tube 12 is 0.5 mm to 2.5 mm, preferably 0.7 mm to 2.1 mm.

[0044] The flow rate of the liquid in the pore of the spinning nozzle 1 is 5 mL / min to 12 mL / min, preferably 7 mL / min to 10 mL / min. Here, the flow rate of the liquid in the pore refers to the respective flow rates of the spinning solution L1 and the mesoporous solution L2 (for example, the flow rate of the spinning solution L1 in the outer tube 11 is 5 mL / min to 12 mL / min, and the flow rate of the mesoporous solution L2 in the inner tube 12 is 5 mL / min to 12 mL / min).

[0045] In one embodiment of the present invention, after the formation of the hollow fiber precursor P', the hollow fiber manufacturing process further includes removing the hollow fiber precursor P' from the solidification bath T, performing a washing and drying treatment, and finally performing a heat treatment to form a composite hollow fiber P consisting of incineration bottom ash and activated carbon material.

[0046] Examples of drying methods include, for instance, air-drying the moist hollow fiber precursor at room temperature, or drying it in a drying apparatus (such as an oven) at a temperature of 50°C to 200°C until the moisture and organic solvent in the fiber are completely evaporated.

[0047] The heat treatment may, for example, involve placing a dried hollow fiber precursor in a high-temperature furnace and performing the heat treatment according to the following heat treatment process: The calcination stage involves raising the temperature to 300°C to 800°C at a rate of 1°C / min to 5°C / min and maintaining it for 0.5 to 12 hours (e.g., 1 hour) to remove high-molecular-weight polymers (e.g., PVP and PESf). In the sintering stage, the temperature is continuously raised to a sintering temperature of 1100°C to 1200°C and maintained for 0.5 to 12 hours (e.g., 3 hours) to sinter the inorganic metal components in the incineration ash and form a stable composite hollow fiber structure (diameter shrinkage rate after sintering is approximately 5% to 30%). Finally, the temperature of the fibers is lowered to room temperature by natural cooling to complete the production of the composite hollow fiber.

[0048] Notably, the incinerated bottom ash sorted in the above sorting process contains a specific proportion of calcium compounds (such as calcium oxide and calcium hydroxide) and a calcium / silicon weight ratio, which helps to lower the sintering temperature in the subsequent production of incinerated bottom ash activated carbon composite hollow fiber (BAACHF), eliminating the need to add other catalysts (such as AlF3) or metal fluxes.

[0049] If the incineration bottom ash is not sorted and does not have the specific composition ratio described above, it may be unfavorable for the production of hollow fibers (for example, the required sintering temperature may be too high, or hollow fibers may not be able to be formed).

[0050] Furthermore, mixing incinerated bottom ash with activated carbon material is advantageous in increasing the specific surface area of ​​the composite hollow fibers, providing good adsorption performance for impurities and organic pollutants.

[0051] Referring to Figures 5A and 5B, these are scanning electron microscope (SEM) images of a cross-section of a composite hollow fiber (BAACHF) of a specific embodiment of the present invention.

[0052] In this specific embodiment, as the incineration main ash, the incineration main ash having the composition shown in FIG. 2 was selected, and a pretreatment operation was performed on the incineration main ash. The pretreatment operation included putting the incineration main ash into an oven at 150°C to remove moisture, then pulverizing it, putting the pulverized incineration main ash through a 45-μm sieve for sieving, and putting the sieved incineration main ash into a high-temperature furnace at 750°C and holding it for 3 hours to remove organic substances, thereby obtaining incineration main ash powder. Next, 36 parts by weight of incineration main ash powder, 4 parts by weight of activated carbon material, 54 parts by weight of N-methylpyrrolidone (NMP), and 1 part by weight of polyvinylpyrrolidone (PVP) were mixed, and after being ball-milled in a planetary ball mill at a revolution speed of 180 rpm for 48 hours, 5 parts by weight of polyethersulfone (PESf) was further added and ball-milled for 48 hours to form a spinning solution in which the main ash / activated carbon was compounded. Next, the outer tube of the spinning nozzle had a diameter of about 3 mm, the inner tube had a diameter of about 1 mm, the liquid flow rate of the outer tube of the spinning nozzle of the spinning solution was 7 mL / min, and the liquid flow rate of the mesoporous solution (deionized water) of the inner tube was 7 mL / min, and hollow fiber spinning was performed by dry-wet spinning. The sintering temperature of the hollow fiber was 1,150°C.

[0053] As can be seen from FIGS. 5A and 5B, although the inner and outer walls of the composite hollow fiber are slightly rough, they are overall smooth. The central part of the cross-section of the composite hollow fiber is dense and sponge-like. Furthermore, the addition of activated carbon increases the specific surface area of the hollow fiber, which is helpful for the adsorption of impurities.

[0054] Regarding the size, the length of the incineration main ash activated carbon composite hollow fiber (BAACHF) of the embodiment of the present invention may be 3 cm to 15 cm, the outer diameter may be 1.0 mm to 2.5 mm, the inner diameter may be 0.6 mm to 1.8 mm, and the wall thickness may be 0.1 mm to 0.4 mm, but the present invention is not limited thereto.

[0055] Also, the specific surface area S of the incineration main ash activated carbon composite hollow fiber (BAACHF) BET is 0.3 m 2 / g to 0.9 m 2 / g, preferably 0.5 m[[ID=1十九]] 2 / g to 0.75 m 2 / g, and the average pore diameter D of the micropores of the hollow fiberp The specific surface area S of the hollow fiber is 650 nm to 1,150 nm, preferably 900 nm to 1,050 nm. Notably, micropores with an average pore diameter exceeding 50 nm belong to macroporous materials with larger pores, and having larger pores makes them suitable for adsorbing larger molecules and colloidal substances, and allows fluids to pass through easily. Here, the specific surface area S of the hollow fiber BET and average pore diameter D p This can be analyzed using a gas adsorption analyzer (e.g., N2 adsorption / desorption method), but the present invention is not limited thereto.

[0056] Figure 6 shows the Fourier transform infrared spectroscopy (FTIR) analysis results of composite hollow fiber (BAACHF) and activated carbon material (AC) according to an embodiment of the present invention.

[0057] The analysis results show that the FTIR spectrum of BAACHF is approximately 3475 cm⁻¹. -1 It was found that it exhibits an OH stretching vibration absorption peak. This characteristic peak reflects the structural hydrophilicity of BAACHF, which may be advantageous for subsequent adsorption and chemical reaction behavior. FTIR analysis of AC (activated carbon) showed that in the high wavenumber region (approximately 3188 cm⁻¹), -1 ) shows an OH stretching vibration absorption peak. At the same time, approximately 1568 cm -1 A C=C bond absorption peak appears in the wavenumber region at approximately 1154 cm⁻¹. -1 A CO absorption peak appears in the nearby wavenumber region. The FTIR spectrum of BAACHF shows an OH stretching vibration peak, but no clear C=C characteristic absorption peak is observed. The AC content of BAACHF is relatively low and uniformly distributed, so other functional groups were not analyzed, but it is suitable for adsorption and functional applications under specific conditions.

[0058] Furthermore, the incinerator ash activated carbon composite hollow fiber (BAACHF) according to the embodiment of the present invention is suitable for wastewater treatment, such as dye adsorption and reduction of COD values ​​in wastewater.

[0059] In one embodiment, tests were conducted to measure the dye adsorption and COD removal efficiency of the manufactured composite hollow fiber (BAACHF) in wastewater. Below, the adsorption experiment and the test method and results for chemical oxygen demand (COD) removal efficiency of a methyl blue (MyB) dye solution using the incineration ash activated carbon composite hollow fiber (BAACHF) described in this application as an adsorbent are explained.

[0060] The experimental method involved using 50 mL of methyl blue dye (MyB) solution as the test solution, first adding 2 g of adsorbent (BAACHF) to the solution, and then placing it in a reciprocating shaking bath and stirring at a speed of 100 rpm. The experimental design included combinations of multiple variables. Specifically, the contact times were set to 0 minutes, 10 minutes, 30 minutes, 60 minutes, 120 minutes, and 180 minutes, the initial MyB concentrations were 50 mg / L, 100 mg / L, or 200 mg / L, and the temperatures were 25°C, 35°C, 45°C, and 60°C, respectively. After the adsorption experiment was completed, the treated solution was filtered through 0.22 μm filter paper, and the residual dye was measured using a spectrophotometer to evaluate the dye adsorption effect. Furthermore, the change in chemical oxygen demand (COD) was measured using a closed potassium dichromate reflux method to evaluate the COD removal efficiency.

[0061] More specifically, COD removal efficiency can be defined by comparing the COD before and after treatment. Specifically, it is possible to first measure the initial COD value of the original liquid under test, and then measure the final COD value after adsorption treatment and filtration. The COD removal efficiency (%) is ((initial COD value - final COD value) / initial COD value) × 100%. A higher value indicates that the adsorbent is more effective at removing organic pollutants from wastewater.

[0062] In Experimental Example 1, the initial MyB concentration was 200 mg / L, the adsorption temperature was 25°C, and the adsorption time was 180 minutes. Regarding the dye adsorption effect, the composite hollow fiber (BAACHF) significantly removed the blue color of the MyB dye within approximately 10 minutes, decolorizing the solution. This indicates a rapid initial adsorption reaction to the MyB dye. According to the experimental results, the adsorption capacity or adsorption ability (qe) of the composite hollow fiber (BAACHF) for MyB was approximately 3 mg / g to 5 mg / g (e.g., 4.3 mg / g) over 180 minutes. Furthermore, the COD removal efficiency of the composite hollow fiber (BAACHF) to the test solution was approximately 50% to 80% (e.g., 64.7%) under the above conditions, demonstrating relatively excellent organic pollutant removal efficiency.

[0063] Overall, under conditions of an initial methyl blue concentration of 200 mg / L and a solution temperature of 25°C, adding 2 g of composite hollow fiber to 50 mL of methyl blue solution and stirring at 100 rpm reduced the methyl blue concentration in the solution by at least 90% within 180 minutes. The adsorption capacity was 3 mg / g to 5 mg / g, and the COD removal efficiency was 50% to 80%.

[0064] Figure 7 shows the test results of dye adsorption and COD removal efficiency of composite hollow fibers (BAACHF) according to an embodiment of the present invention at different contact times with test solutions (Experimental Example 2).

[0065] In Experimental Example 2, the initial MyB concentration was 150 mg / L, the adsorption temperature was 25°C, the weight of the adsorbent was 2 g, the solution volume was 50 mL, and the observed contact times were 10 minutes, 30 minutes, 60 minutes, 120 minutes, and 180 minutes. As can be seen from Figure 7, the adsorption capacity (qe) of the composite hollow fiber (BAACHF) for MyB increased from 1.8 mg / g to approximately 3.0 mg / g between 10 and 180 minutes, and the COD removal efficiency increased from 42% to 70.4%.

[0066] The adsorption behavior of BAACHF to MyB was analyzed using pseudo-first order (PFO) and pseudo-second order (PSO) adsorption dynamics models.2 It is approximately 0.9438, PSO's R 2 The ratio was approximately 0.9918, indicating that the pseudo-quadratic model had a better fit. This result suggests that the adsorption process of BAACHF to MyB tends to be chemisorption rather than simple physicoadsorption, which means that the active sites on the surface of BAACHF can form stronger bonds with the dye molecules (MyB), thus improving the stability and efficiency of adsorption.

[0067] Figure 8 shows the test results of dye adsorption and COD removal efficiency at different initial MyB dye concentrations for composite hollow fibers (BAACHF) according to an embodiment of the present invention (Experimental Example 3).

[0068] In Experimental Example 3, the initial MyB concentrations were 50 mg / L, 100 mg / L, and 200 mg / L, the adsorption temperature was 25°C, the weight of the adsorbent was 2 g, the solution volume was 50 mL, and the observed contact time was 180 minutes. As shown in Figure 8, both the adsorption capacity (qe) and COD removal efficiency of the composite hollow fiber (BAACHF) for MyB increased with increasing initial dye MyB concentration. Here, in the range where the initial MyB concentration increased from 50 mg / L to 200 mg / L, the adsorption capacity (qe) increased from 0.7 mg / g to 4.3 mg / g, and the COD removal efficiency increased from 50% to 64.7%. This indicates that the composite hollow fiber (BAACHF) can exhibit superior dye adsorption and COD removal efficiency even at high dye concentrations.

[0069] In Experiment Example 4, not shown in the figure, the adsorption temperatures were 25°C, 35°C, 45°C, and 60°C, the initial MyB concentration was 200 mg / L, the weight of the adsorbent was 2 g, the solution volume was 50 mL, and the observed contact time was 180 minutes. The results of the experiment showed that both the adsorption capacity (qe) and COD removal efficiency of the composite hollow fiber (BAACHF) for MyB decreased with increasing temperature. In the temperature range of heating from 25°C to 60°C, the adsorption capacity (qe) decreased from 4.3 mg / g to 3.6 mg / g, and the COD removal efficiency decreased from 64.7% to 53.7%. These experimental results indicate that the composite hollow fiber (BAACHF) of this embodiment exhibits excellent dye adsorption and COD removal efficiency at room temperature (25°C).

[0070] Figure 9 shows the analysis of the zero charge point (pH_pzc) of the composite hollow fiber (BAACHF) according to an embodiment of the present invention. The analysis revealed that when the initial pH of the solution of the composite hollow fiber (BAACHF) according to an embodiment of the present invention is approximately 10.5 to 11.5 (for example, 10.97), δpH (change in pH value) approaches 0. In other words, the zero charge point (pH_pzc) of the composite hollow fiber (BAACHF) according to the embodiment of the present invention is 10.5 to 11.5.

[0071] Generally, when the pH of a solution exceeds the zero charge point (pH_pzc), the surface of the adsorbent becomes negatively charged. Conversely, when the pH of the solution is lower than pH_pzc, the surface of the adsorbent becomes positively charged.

[0072] In the MyB adsorption experiment, the pH of the MyB dye solution was approximately 3, which is lower than the zero charge point of the composite hollow fiber (BAACHF) at 10.97 (pH_pzc), indicating that the surface of the BAACHF is positively charged in the MyB solution environment. Since MyB is a dye with an anionic group, the positive charge on the surface of the BAACHF promotes the electrostatic attraction between positive and negative charges, thereby promoting the adsorption of MyB molecules onto the surface of the BAACHF.

[0073] To explain, the point of zero charge (PZC) is defined as the pH value at which the static charge on a surface becomes zero. The analysis of the point of zero charge (pH_pzc) may also be measured by the pH shift method. This method involves preparing a series of electrolyte solutions of the same concentration, where the initial pH range covers a target pH interval (e.g., pH 8-12). A fixed amount of the sample (such as an adsorbent) is added to each solution, and the mixture is stirred for a set period of time until the sample and solution reach equilibrium. After equilibrium, the final pH value of each solution is measured. The point at which the final pH equals the initial pH (δpH=0) is the point of zero charge of the sample.

[0074] Furthermore, in experimental data not shown, FTIR analysis indicated that after the MyB dye was adsorbed onto BAACHF, approximately 1652 cm³ was observed. -1 It was found that a new absorption peak was generated at that location. Compared to BAACHF before adsorption, the new peak exhibits NH-bonding characteristics, suggesting that this was not simple physical adsorption, but rather that a chemical bond was formed between the MyB molecule and the surface of BAACHF during the adsorption process.

[0075] Furthermore, XPS analysis revealed that before adsorbing MyB, BAACHF primarily exhibited a CC peak (approximately 284.6 eV) in its C1s spectrum. After BAACHF was adsorbed onto MyB, a new shifted peak (at approximately 289.5 eV) appeared in the C1s spectrum. This is attributed to a C=O=C bond, indicating that the introduction of the MyB molecule created a new chemical bond on the surface of BAACHF. This result demonstrates that the interaction between MyB and BAACHF is not merely a physical action, but that new functional groups and chemical bonds are indeed generated during the adsorption process, thereby improving the efficiency and stability of dye removal.

[0076] [Advantageous effects of the embodiment] As described above, the incinerator bottom ash activated carbon composite hollow fiber and the method for producing the same according to the present invention can produce hollow fibers with relatively high economic value from incinerator bottom ash, and the hollow fibers are particularly suitable for wastewater treatment such as adsorption of organic impurities.

[0077] Furthermore, this invention allows for the formation of hollow fibers at a lower sintering temperature without the need to separately add flux, by selecting incinerator bottom ash with a high calcium content and imparting flux properties to it, thereby reducing energy consumption and costs. A spinning solution is prepared by uniformly dispersing the powder of incinerator bottom ash in an organic solvent and a high-molecular-weight polymer, and hollow fiber precursors are formed by wet-dry spinning. By stably solidifying the fibers at a relatively low sintering temperature, a uniform pore distribution and appropriate pore size are obtained. The final product maintains good structure and mechanical strength even under low-temperature sintering conditions and has the ability to adsorb impurities, making it advantageous for water treatment and wastewater purification applications, thus significantly improving economic benefits and practical value. Moreover, mixing incinerator bottom ash with activated carbon material is advantageous in increasing the specific surface area of ​​the composite hollow fibers, providing good adsorption performance for impurities and organic pollutants. Furthermore, the activated carbon material can be used as a carrier for the hollow fibers, which is advantageous for separation and recovery from the aqueous phase environment.

[0078] The information disclosed herein represents only preferred and feasible embodiments of the present invention, and the claims of the present invention are not limited thereto. Therefore, all equivalent technical modifications made using the description and drawings of the present invention are included within the scope of the claims of the present invention. [Explanation of Symbols]

[0079] S110...Process S110 S120...Process S120 S130...Process S130 S140...Process S140 100... Spinning machine 1... Spinning nozzle 11...Outer tube 12...Inner tube L1...Spinning solution L2...Mesoporous solution T...coagulation bath P'...Hollow fiber precursor P...Composite hollow fiber

Claims

1. A sorting process including the selection of incineration bottom ash in which the calcium content is greater than the silicon content in its elemental composition, A spinning solution manufacturing operation comprising mixing the selected incinerated bottom ash with activated carbon material, an organic solvent, and a polymer to form a spinning solution, wherein the weight ratio of the incinerated bottom ash to the activated carbon material (incinerated bottom ash: activated carbon material) is 5:1 to 15:1, A method for producing incinerator ash-activated carbon composite hollow fibers, comprising: a hollow fiber manufacturing operation, which includes spinning the aforementioned spinning solution in a spinning apparatus by a wet-dry spinning method to form a hollow fiber precursor, and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form a composite hollow fiber consisting of the incinerator ash and the activated carbon material.

2. The method for producing incinerator bottom ash-activated carbon composite hollow fibers according to claim 1, wherein the activated carbon material is activated carbon powder, and the weight ratio of the incinerator bottom ash to the activated carbon material (incinerator bottom ash: activated carbon material) is 7:1 to 12:

1.

3. The method for producing hollow fibers made of incinerated ash and activated carbon composite, according to claim 2, wherein the weight ratio of the incinerated ash to the activated carbon material (incinerated ash: activated carbon material) is 8:1 to 10:

1.

4. In the sorting process, the elemental composition of the sorted incinerated bottom ash satisfies the following conditions as a result of scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) analysis, according to the method for producing incinerated bottom ash activated carbon composite hollow fibers as described in claim 1. (1) The weight percentage concentration of calcium element is 15 wt% or more, and (2) The weight ratio of the weight percentage concentration of calcium element (calcium (Ca) / silicon (Si)) to the weight percentage concentration of silicon element shall be 2 or more.

5. The method for producing incinerator bottom ash activated carbon composite hollow fibers according to claim 1, wherein the calcium element in the incinerator bottom ash is derived from a calcium compound, the calcium compound includes calcium oxide and calcium hydroxide, the silicon element is derived from a silicon compound, the silicon compound includes silicon dioxide, and in the sorting process, the composition of the sorted incinerator bottom ash satisfies the following conditions as a result of analysis by inductively coupled plasma emission spectrometry (ICP-OES). (1) The weight percentage concentration of the calcium compound is 30 wt% or more, and (2) The weight percentage concentration of the calcium compound shall be 1.2 times or more the weight percentage concentration of the silicon compound.

6. A method for producing incinerated ash activated carbon composite hollow fibers according to claim 1, further comprising, after the sorting work and before the spinning solution production work, a pretreatment work for incinerated ash, wherein the pretreatment work for incinerated ash includes sequentially performing drying, crushing, sieving, and calcination on the sorted incinerated ash to remove residual moisture and organic matter from the incinerated ash and to obtain incinerated ash with an average particle size of 60 μm or less.

7. The drying process includes placing the selected incinerated bottom ash into a drying apparatus and drying it at a drying temperature of 50°C to 200°C in order to remove the residual moisture. The aforementioned crushing process includes crushing the dried incinerated bottom ash with a crushing device or crushing means, The sieving process includes obtaining incinerated bottom ash with an average particle size of 60 μm or less by sieving the crushed bottom ash with a particle size sorter, The method for producing incinerated ash-activated carbon composite hollow fibers according to claim 6, wherein the calcination treatment includes placing the sieved incinerated ash into a high-temperature apparatus and calcining it at a calcination temperature of 300°C to 800°C to remove the organic matter remaining in the incinerated ash.

8. The method for producing incineration ash activated carbon composite hollow fibers according to claim 1, wherein the organic solvent is at least one selected from the group consisting of N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and dimethyl sulfoxide (DMSO), and the polymer is at least one selected from the group consisting of polyvinylpyrrolidone (PVP), polyethersulfone (PESf), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyetherimide (PEI), polyetheretherketone (PEEK), polyvinyl alcohol (PVA), and polyethylene glycol (PEG).

9. A method for producing hollow fibers made of incinerated ash-activated carbon composite, according to claim 8, wherein the total weight of the spinning solution is 100 wt%, the content of the incinerated ash is 20 wt% to 60 wt%, the content of the activated carbon material is 1 wt% to 15 wt%, the content of the organic solvent is 25 wt% to 60 wt%, and the content of the polymer is 0.1 wt% to 15 wt%.

10. The method for producing incinerated ash activated carbon composite hollow fibers according to claim 1, wherein the spinning solution production operation includes grinding the spinning solution with a planetary ball mill, which is a grinding device, the orbital speed of the planetary ball mill is 120 rpm to 240 rpm, and the ball mill grinding time is 3 hours or more.

11. An incinerator ash activated carbon composite hollow fiber manufactured by the method for manufacturing incinerator ash activated carbon composite hollow fiber according to any one of claims 1 to 10, wherein the calcium content in the elemental composition of the incinerator ash activated carbon composite hollow fiber is greater than the silicon content, and the specific surface area S of the incinerator ash activated carbon composite hollow fiber ＢＥＴ is 0.3m ２ / g to 0.9m ２ / g, and the average pore size D of the micropores. ｐ A hollow fiber composite of activated carbon from incinerated ash, characterized by having a wavelength of 650 nm to 1,150 nm and a zero charge point of 10.5 to 11.

5.

12. The incineration ash activated carbon composite hollow fiber according to claim 11, wherein the incineration ash activated carbon composite hollow fiber is used as an adsorbent, and when the initial methyl blue concentration is 200 mg / L and the solution temperature is 25°C, 2 g of the adsorbent is added to 50 mL of methyl blue solution and stirred at 100 rpm, the methyl blue concentration in the solution can be reduced by at least 90% within 180 minutes, the adsorption capacity is 3 mg / g to 5 mg / g, and the COD removal efficiency is 50% to 80%.

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