A porous adsorbing material, its preparation method and application

Abstract

The present application relates to a kind of porous adsorbing materials and its preparation method and application.The porous adsorbing material is the shell of calcium removal crustacean, with rough surface, pore size 1-2 μm channel and ordered fiber bundle structure, keep the structure of crustacean shell complete and abundant functional group, to a variety of nano plastic particles has good capture capacity, can be used in water body nano plastic particles, nano plastic particles, oil pollution various pollution removal.

Description

Technical Field

[0001] This invention relates to the field of water pollution control technology, and in particular to a porous adsorption material, its preparation method, and its application. Background Technology

[0002] Due to their ubiquity in the environment and accumulation in the food chain, microplastics readily infiltrate and persist in organisms. Furthermore, the potential risks of nanoparticles (NPs) are incalculable, as they have been shown to enter the human circulation through human feces, blood, and placenta, potentially causing intestinal inflammation and cell damage. More worryingly, NPs are more difficult to eliminate than conventional microplastics, and their combined toxicity under conditions of adsorbing organic pollutants and heavy metals is self-evident. Therefore, exploring methods for removing NPs is urgent and a pressing challenge. Various traditional strategies for removing microplastics, such as filtration, coagulation, and adsorption, have been employed, achieving satisfactory removal performance by fully utilizing functional groups and surface charges. However, due to size limitations, they cannot capture NPs. For example, filtration methods used in wastewater treatment plants may involve materials that are inconvenient or susceptible to secondary contamination, potentially exacerbating the situation.

[0003] Existing technologies utilize the porous structure of biochar or activated carbon materials to adsorb pollutants, achieving satisfactory adsorption results. For example, Chinese patent application CN109503294A uses crayfish shells from catering waste as raw material, which are modified with Mg and then pyrolyzed at high temperature to produce biochar, which can be used to adsorb and remove phosphorus from wastewater. However, the porous structure of biochar is obtained through high-temperature carbonization, which may significantly reduce the large number of potentially beneficial functional groups in the crayfish shells. Summary of the Invention

[0004] This invention discovers that crayfish shells are assembled from inorganic nanoparticle layers and organic scaffold structures. This invention uses a simple and scalable processing method to maintain the complete structure and abundant functional groups of the crayfish shell, thus preparing a porous crayfish shell. This material has a good capture ability for various nanoplastic particles and can be used to remove nanoplastic particles from water.

[0005] This invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a porous adsorbent material, which is the shell of a crustacean for removing calcium, having a rough surface, pores with a diameter of 1-2 μm and an ordered fiber bundle structure.

[0007] In some embodiments of the present invention, the crustacean is a shrimp or a crab.

[0008] In some embodiments of the present invention, the shell of the crustacean to which calcium has been removed is the shell of a crustacean that has been thoroughly soaked in acid.

[0009] Secondly, the present invention provides a method for preparing a porous adsorbent material, comprising:

[0010] a) Contacting the shell of a crustacean with a water-soluble aqueous composition; said composition comprising an acid that can form a soluble calcium salt with calcium, wherein said acid is present in the aqueous composition at a concentration of 1% to 7%;

[0011] And b) maintain contact between the crustacean's shell and the aqueous composition for an appropriate period of time to cause calcium in the crustacean's shell to separate from the shell.

[0012] In some embodiments of the present invention, the crustacean's shell is in contact with the aqueous composition for a period of 100 to 130 minutes.

[0013] In some embodiments of the present invention, the acid is one or more of hydrochloric acid, nitric acid, formic acid, and acetic acid.

[0014] In some embodiments of the present invention, the preparation method further includes:

[0015] c) Expose the crustacean's shell to an alkaline solution;

[0016] d) Maintain contact between the crustacean's shell and the alkaline solution for an appropriate period of time to allow the oils and proteins on the crustacean's shell to separate from the shell.

[0017] In some embodiments of the present invention, the crustacean's shell is in contact with the alkaline solution for a period of 100 to 130 minutes.

[0018] Thirdly, the present invention provides the application of the above-mentioned porous adsorption material in the field of adsorption of nanoplastic particles.

[0019] In some embodiments of the present invention, the application includes: using porous adsorption materials to adsorb nanoplastic particles in water.

[0020] In some embodiments of the present invention, the application further includes: hot-pressing a porous adsorbent material that adsorbs nanoplastic particles into a sheet.

[0021] Fourthly, the present invention provides a wastewater treatment device comprising the aforementioned porous adsorption material, wherein the wastewater treatment device is used to adsorb heavy metals, nanoplastic particles, and oil stains.

[0022] Fifthly, the present invention provides a sheet material formed by hot pressing using the aforementioned porous adsorption material as a substrate.

[0023] In some embodiments of the present invention, the porous adsorbent material adsorbs nanoplastic particles.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. This invention employs a top-down strategy to process the shells of discarded crustaceans, preserving as much of the crayfish shell's intact structure and abundant functional groups as possible, and preparing a variety of porous adsorbent materials with excellent capture capabilities from nanoplastic particles.

[0026] 2. This invention provides a new approach to processing food waste, avoiding the waste of resources.

[0027] 3. This invention also provides a utilization path for porous adsorption materials that adsorb pollutants, forming an effective closed loop for waste recycling. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 Scanning electron microscope (SEM) images of the original crayfish shell and the porous crayfish shell prepared in Example 1; wherein, (a) represents the original crayfish shell and (b) represents the porous crayfish shell.

[0030] Figure 2 Three-dimensional contour images of the original crayfish shell and the porous crayfish shell prepared in Example 1; wherein, (a) represents the original crayfish shell and (b) represents the porous crayfish shell.

[0031] Figure 3 (a) Stress-strain curves and (b) stress, (c) toughness and (d) stiffness comparison of the original crayfish shell and the porous crayfish shell.

[0032] Figure 4 This demonstrates the resilience of the porous crayfish shell.

[0033] Figure 5 The study demonstrates a comparison of the toughness of a raw crayfish shell and a porous crayfish shell.

[0034] Figure 6 X-ray diffraction patterns of the original crayfish shell, the porous crayfish shell, and chitin.

[0035] Figure 7 Scanning electron microscope image of PS nanoplastics (100 nm) captured in porous crayfish shells.

[0036] Figure 8 The effects of time (a), PS nanoplastic concentration (b), pH (c), and temperature (d) on the capture of PS nanoplastic (100 nm) in pristine crayfish shells and porous crayfish shells are shown.

[0037] Figure 9 The effects of nanoplastic size (a), water body (b), and nanoplastic type (c) on the capture of PS nanoplastics (100 nm) by pristine crayfish shells and porous crayfish shells are shown.

[0038] Figure 10 The porosity (a) and zeta potential (b) of porous crayfish shells compared to virgin crayfish shells are shown. The adsorption mechanism of PS nanoplastics captured by porous crayfish shells includes XPS N1s fractionation (c), XPS O1s fractionation (d), MD simulation (e), and IGMH independent gradient model (f).

[0039] Figure 11 Electron micrographs (a) showing the desorption of PS nanoplastics by porous crayfish after adsorption and (b) show the performance of cyclic adsorption of PS nanoplastics.

[0040] Figure 12 Optical photographs (a), compressive stress (b), and thermal stability (c) of a porous crayfish shell-PS hot press plate are shown. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] The porous adsorbent material provided by this invention is the shell of a crustacean for removing calcium, and has a rough surface, pores with a diameter of 1-2 μm and an ordered fiber bundle structure.

[0043] The trapping mechanism of this porous adsorbent material mainly includes physical interception, hydrogen bonding, and electrostatic interactions. Both pores and functional groups play an equal role; the pores can intercept nanoplastic particles, and hydrogen bonds exist between the acetamino and hydroxyl functional groups on the chitin, the main component of the fiber bundle. It is speculated that it may have some removal capacity for heavy metals and oils.

[0044] In some embodiments of the present invention, the crustacean is a shrimp or crab, preferably a crayfish. The porous adsorbent material provided in the examples is a porous crayfish shell.

[0045] In some embodiments of the present invention, the shell of the crustacean to which calcium has been removed is the shell of a crustacean that has been thoroughly soaked in acid.

[0046] The method for preparing porous adsorbent materials provided by the present invention includes:

[0047] a) Contacting the shell of a crustacean with a water-soluble aqueous composition; said composition comprising an acid that can form a soluble calcium salt with calcium, wherein said acid is present in the aqueous composition at a concentration of 1% to 5%;

[0048] And b) maintain contact between the crustacean's shell and the aqueous composition for an appropriate period of time to cause calcium in the crustacean's shell to separate from the shell.

[0049] In some embodiments of the present invention, the crustacean's shell is in contact with the aqueous composition for a period of 100 to 130 minutes.

[0050] In some embodiments of the present invention, the acid is one or more of hydrochloric acid, nitric acid, and formic acid, preferably hydrochloric acid.

[0051] In some embodiments of the present invention, chelates may be added to the aqueous composition to promote the separation of calcium from the shell.

[0052] In some embodiments of the present invention, the preparation method further includes:

[0053] c) Expose the crustacean's shell to an alkaline solution;

[0054] d) Maintain contact between the crustacean's shell and the alkaline solution for an appropriate period of time to allow the oils and proteins on the crustacean's shell to separate from the shell.

[0055] In some embodiments of the present invention, the crustacean's shell is in contact with the alkaline solution for a period of 100 to 130 minutes.

[0056] In some embodiments of the present invention, the alkaline solution is a NaOH solution or a KOH solution with a concentration of 2%-7%.

[0057] It is worth noting that in the preparation method of porous adsorbent materials, the shells of crustaceans cannot be repeatedly treated. In particular, repeated treatment with alkali solution will affect the integrity of the shell structure, making the porous adsorbent material easy to break. The tensile properties are best after a single alkali solution treatment.

[0058] This invention provides the application of the above-mentioned porous adsorption material in the field of adsorption of nanoplastic particles.

[0059] In some embodiments of the present invention, the application includes: using porous adsorbent materials to adsorb nanoplastic particles from water. The nanoplastic particles include at least one or more of PET, PMMA, and PS. The water may also contain heavy metal ions and oils; the porous adsorbent material surface is rich in hydrogen bonds and organic groups, giving it a certain adsorption capacity for heavy metals and oils.

[0060] In some embodiments of the present invention, the application further includes: hot-pressing the porous adsorbent material that adsorbs nanoplastic particles into a plate for recycling the porous adsorbent material that adsorbs nanoplastic particles.

[0061] The wastewater treatment device provided by the present invention includes the above-mentioned porous adsorption material, and the wastewater treatment device is used for treating wastewater containing one or more of nano-plastic particles, heavy metals, and oil.

[0062] The sheet material provided by the present invention is hot-pressed from the above-mentioned porous adsorption material as a substrate. Its thermal stability is comparable to that of commercially available plastic sheets of the same specifications. Furthermore, the substrate of the sheet material is biodegradable, and its use in replacing plastic sheets can reduce pollution.

[0063] Unless otherwise specified, the term "raw crayfish shell" refers to an untreated crayfish shell; the term "porous crayfish shell" refers to the porous skeleton of a crayfish that has been thoroughly soaked in acid and alkali solutions, rinsed, and dried.

[0064] Unless otherwise specified, the crayfish shells used in the following examples were collected from a seafood market (Wuhan, China) and processed in the same way for subsequent experiments. Fluorescently labeled polystyrene nanoplastics (PS NPs, 100 nm, excitation peak at 540 nm, emission peak at 580 nm) were obtained from China Big Goose (Tianjin) Technology Co., Ltd. Fluorescently labeled polyethylene terephthalate (PET, excitation peak at 540 nm, emission peak at 580 nm) and polymethyl methacrylate (PMMA, excitation peak at 488 nm, emission peak at 518 nm) nanoplastics, 100 nm in diameter, were purchased from China National Biotec Group Co., Ltd. and China Comay New Materials Co., Ltd., respectively. Chemical reagents such as hydrochloric acid (HCl), sodium hydroxide (NaOH), ethanol, anhydrous sodium acetate (NaAc), and Coomassie Brilliant Blue G-250 were purchased from Sinopharm Group (China). N-dimethylformamide (DMF 99.9%) and pure chitin (α-CT, Mw = 56.3 × 10⁻⁶) were used. 4 The reagent was supplied by Sigma-Aladdin (USA). Ultrapure water with a resistivity of 18.25 MΩcm was used throughout the reagent preparation process.

[0065] Example 1

[0066] After removing the remaining shrimp meat from the crayfish shells collected from the seafood market, use dish soap to preliminarily clean the surface oil stains. The cleaned crayfish shells are the original crayfish shells.

[0067] The raw crayfish shells were soaked in hydrochloric acid (3%, v / v) until no more visible impurities were produced. The shells were then removed and the residual acid was washed away. The soaking time was approximately 12 hours. The crayfish shells soaked in hydrochloric acid were then soaked in NaOH solution (5%, w / v) until the NaOH solution no longer changed color and no impurities were found. The soaking time was approximately 12 hours. The crayfish shells soaked in NaOH solution were rinsed with ultrapure water until the pH of the rinsing solution became neutral. After rinsing, the shells were dried in an oven at 60°C to obtain the organic framework of the crayfish shell, i.e., the porous crayfish shell.

[0068] Physicochemical characterization and mechanical property testing were performed on the original crayfish shell and the porous crayfish shell. The results are as follows:

[0069] Figure 1 The scanning electron microscope images shown indicate that the original crayfish shell has a flat and smooth surface covered with minerals, while the porous crayfish shell shows a relatively rough surface with channels with a pore size of 1-2 μm and an ordered fiber bundle structure.

[0070] Figure 2 The three-dimensional contour images shown indicate that the surface height difference of the original crayfish shell is only 13.13 μm, while the surface height difference of the porous crayfish shell is as high as 76.09 μm, indicating a significant increase in surface roughness compared to the original crayfish shell.

[0071] Figure 3 The comparison of mechanical properties shows that the tensile strength of the original crayfish shell is only 14.37 MPa, while the tensile strength of the porous crayfish shell is as high as 60.13 MPa, and its stiffness is about three times that of the original crayfish shell. The toughness of the porous crayfish shell is 278.98 MJ·m. -3 The thickness of the shell increased by 1033.60% compared to the original crayfish shell. These results indicate that the highly ordered fibrous structure endows the porous crayfish shell with good mechanical properties.

[0072] Figure 4 , Figure 5 The comparison of the toughness of the original crayfish shell and the porous crayfish shell shows that the original crayfish shell is not resistant to bending and is very easy to break, while the porous crayfish shell can be bent and twisted at will, showing good flexibility.

[0073] The calcium and protein content of porous crayfish shells were determined by inductively coupled plasma mass spectrometry and Coomassie brilliant blue method. The results are shown in Table 1. The calcium in the porous crayfish shells was basically completely removed, leaving only some protein.

[0074] Table 1. Calcium and protein content in the shell of porous crayfish

[0075]

[0076] Figure 6 The X-ray diffraction spectra shown indicate that the typical characteristic peak of the original crayfish shell is located at 29.12°, corresponding to the calcite diffraction peak position of (104). The typical characteristic peaks of the porous crayfish shell appear at 12.58°, 19.36°, 23.54°, and 26.32°, corresponding to chitin's (021), (110), (130), and (013) morphologies. These results indicate that the chitin-based framework in the porous crayfish shell remains intact during the treatment process, and the crystal structure does not undergo significant changes.

[0077] Example 2

[0078] This embodiment verifies the ability of raw crayfish shells and porous crayfish shells to capture nanoplastic particles.

[0079] Experimental method: Weigh the original crayfish shell and the porous crayfish shell, and add 0.3 mg mL of each. -1 Fluorescently labeled polyethylene nanoparticles (PS NPs) were suspended in a suspension and subjected to full adsorption in a constant-temperature shaker (SHZ-82, ZBR, China). The capture kinetics were studied during adsorption using a fluorescence spectrometer (FS5, Edinburgh, UK). The residual concentration was calculated based on the fluorescence intensity before and after capture. The adsorption performance was as follows: Figure 7 The electron microscope image is shown.

[0080] In this embodiment, the number of PS NPs captured on the sample is calculated using the following equation:

[0081] Capture capacity(Q)=(c1-c0)×v / m

[0082] Among them, Q(mg g) -1 (c0, mg / mL) represents the number of PS NPs captured per unit mass of sample. The pre-capture PS NP count (c0, mg / mL) is obtained by converting fluorescence intensity. -1 ) and after capture (c1, mg mL) -1 The concentration of NP is V(mL), the volume of the NP suspension is V(mL), and the weight of the sample is m(g).

[0083] 1. In order to determine the optimal reaction time for adsorption of PS NPs by raw crayfish shells and porous crayfish shells, this example tested the fluorescence intensity at different adsorption times (1 minute to 12 hours). Figure 8(a) shows that the capture capacity of the porous crayfish shell surges within 0–20 minutes, then gradually decreases, reaching equilibrium within 120 minutes. In contrast, the original crayfish shell reaches capture equilibrium within 20 minutes, but its capture capacity does not increase further.

[0084] 2. Set the initial concentration of PS NPs to 0.1 to 0.5 mg / mL. -1 Within a certain range, to screen subsequent concentrations. Figure 8 (b) shows that the trapping ability of porous crayfish shells increases with increasing initial PS nanoplastic concentration, at 0.3 mg / mL. -1 The concentration was 68.09 mg g. -1 .

[0085] 3. The pH of fluorescently labeled polyethylene nanoparticles (PS NPs) suspensions was adjusted to 5, 6, 7, 8, and 9 using 1 mM hydrochloric acid and 1 mM NaOH solutions to discuss the effect of pH on the capture of PS NPs by pristine crayfish shells and porous crayfish shells. Figure 8 (c) shows that the porous crayfish shell has good capture capacity in the pH range of 6-8, with a maximum of 81.77 mg g. -1 The original crayfish shell has a much lower capture capacity than the porous crayfish shell.

[0086] 4. The temperature of the isothermal oscillator was set at 293K, 308K, and 323K, which are 20℃, 35℃, and 50℃, to discuss the effect of temperature on the capture of PS NPs by raw crayfish shells and porous crayfish shells. Figure 8 (d) shows that the removal performance of porous crayfish shells for PS NPs significantly improved with increasing temperature of the thermostatic oscillator, indicating that wastewater can be treated during periods of higher air temperature under natural conditions. This is presumably because porous crayfish shells readily form biofilms with microorganisms in the environment at high temperatures, exhibiting adhesiveness, which is more conducive to further enhancing capture capacity compared to lower temperatures.

[0087] 5. The particle size of PS NPs was set in the range of 100 to 1000 nm to evaluate the effect of PS NP size on the capture of PS NPs by pristine crayfish shells and porous crayfish shells. Figure 9 (a) shows that when the particle size of PS NPs is set in the range of 100 to 1000 nm, the porous crayfish shells maintain stable removal performance.

[0088] 6. The performance of raw crayfish shells and porous crayfish shells in capturing PS NPs was investigated under pure water and seawater conditions. Seawater was taken from the Yellow Sea area of ​​Rizhao City, Shandong Province, at a temperature of 25℃. The mass ratio of porous crayfish shells to seawater was 2:100, and the settling time was 6 hours. The basic capture experimental operation was the same as the aforementioned experimental method. Figure 9 (b) shows that the porous crayfish shell has a capture capacity of 68.09 mg g in pure water. -1 The capture capacity of porous crayfish shells in seawater is 87.87 mg g, far exceeding that of the original crayfish shell; -1 The capture capacity is far higher than that of the original crayfish shell and also higher than that of the porous crayfish shell in pure water, indicating that the porous crayfish shell is very suitable for capturing nanoplastic particles in the sea.

[0089] 7. In order to verify the effect of the type of nanoplastic on the capture ability of porous crayfish shells, this invention verified three types of nanoplastic particles: PET, PMMA, and PS. Figure 9 (c) shows that the porous crayfish shell has a capture capacity of 121.99 mg g for PET and PMMA, respectively. -1 and 80.01mg g -1 This indicates that the porous crayfish shell has a good ability to capture various nanoplastic particles and is expected to be applied in various environmental conditions.

[0090] 8. In order to explore the mechanism by which porous crayfish shells capture PS NPs, this invention compares the XPS and porosity tests of raw crayfish shells and porous crayfish shells. Figure 10 (a) shows that decalcification exposes the chitin-based framework pores in the crayfish shell, increasing the porosity of the porous crayfish shell and facilitating the physical interception of nanoplastic particles. Figure 10 (b) shows that both the original crayfish shell and PS NPs are negatively charged. With the exposure of the chitin-based fibrous skeleton, the porous crayfish shell becomes positively charged, which is conducive to capturing PS NPs through electrostatic interactions.

[0091] To gain a deeper understanding of the capture mechanism, we used XPS to analyze the porous crayfish shells before and after capturing nanoplastics. Figure 10 (c) shows that the XPS spectra of N1s in the porous crayfish shell reveal -NC- and -NH2 / -NH3 peaks. + Two peaks. Due to the electrostatic binding between the porous crayfish shell and PS NPs, the -NH3 of the porous crayfish shell after capturing PS NPs... +The peak area increased. Furthermore, after capturing PS NPs, the -NC- peak of the porous crayfish shell shifted from 399.88 eV to 400.02 eV, likely due to the electron-withdrawing effect of the benzene ring on PS leading to a decrease in the electron cloud density of the N atom, attributed to hydrogen bonding and electrostatic interactions between the PS NPs and the porous crayfish shell. Figure 10 (d) The O1s peak results show that the strong attraction of the benzene ring in PS to electrons leads to a decrease in the internal electron density of -OH, and because the hydroxyl group is considered a strong electron-donating group, the binding energy peak shifts towards higher binding energies. Due to the strong effect of the benzene ring, the electron density of -C=O also decreases, with the peak value shifting from 531.09 eV to 531.33 eV. The above analysis indicates that the hydrogen bonding interactions of porous crayfish shells trap nanoparticles are important.

[0092] This embodiment also performed molecular dynamics (MD) simulations on the surface of the porous crayfish shell to further analyze the capture mechanism. The conformation of the porous crayfish shell (mainly chitin) capturing PS eicosamide

[010] indicates that PS NPs have sufficient contact sites on the surface, such as Figure 10 As shown in (e). Figure 10 (f) shows that there is a significant non-bonded interaction between the chitin

[010] surface and the formed PS NPs. Most of the chromatic patches are distributed on the benzene ring and C=O, NH and CH groups of chitin, indicating that the functional groups involved in the interaction are likely mainly acetamino groups, and hydrogen bonding and van der Waals (vdW) interactions are the main interactions. Combined with the previous analysis, the mechanism of the capture process may include physical interception, electrostatic interaction and hydrogen bonding.

[0093] Example 3: Sustainable Application

[0094] This embodiment tested the cyclic capture capability of porous crayfish shells. Due to the different solubilities between porous crayfish shells and PS, DMF was chosen as the solvent for desorption. The porous crayfish shells after capturing PS NPs were immersed in DMF and shaken overnight (12 hours) in a constant-temperature shaker. Figure 11 (a) The results show that the porous crayfish shell exhibits no significant morphological changes and virtually no PS NPs residue, indicating satisfactory desorption performance of DMF. After the fifth cycle of capture, the removal performance of PS NPs from the porous crayfish shell is 73.16% of the original value, demonstrating the reliability of the cyclic capture method. Figure 11 As shown in (b).

[0095] After each capture of PS NPs, the PS NPs on the porous crayfish shell are desorbed into the DMF solution, and the porous crayfish shell is used for the next capture of PS NPs after desorption.

[0096] Example 4: Sustainable application and processing of nanoplastics captured in porous crayfish shells

[0097] To reduce secondary pollution caused by material degradation, this embodiment involves hot-pressing porous crayfish shells, or porous crayfish shells after capturing PS NPs, at 150°C and 100MPa to obtain a smooth-surfaced laminate. Figure 12 As shown in (a), the laminate made from the porous crayfish shells after capturing PSNPs has a wood-like morphology. Figure 12 As shown in (b), the compressive stress of the laminate made from the porous crayfish shell after capturing PS NPs reached 70.30 MPa, which is much higher than that of the laminate made from the porous crayfish shell without nanoplastics (24.12 MPa).

[0098] This invention selects commonly available plastic sheets, such as PMMA, PS, polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), acrylonitrile-butadiene-styrene (ABS), polyamide (PA), polyoxymethylene (POM), and polycarbonate (PC), and compares their thermal stability with that of laminates made from porous crayfish shells after capturing PS NPs. Figure 12 As shown in (c), at 230°C, the laminate made from the porous crayfish shells after capturing PS NPs still maintains a good morphology and can be used to replace common plastic sheets.

[0099] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. The application of porous adsorbent materials in the adsorption of nanoplastic particles in water, characterized by: The porous adsorbent material is the shell of a crustacean with calcium removed, while retaining the chitin-based skeleton, and has a rough surface, pores with a diameter of 1-2 μm, and an ordered fiber bundle structure. The porous adsorbent material is prepared by a method comprising the following steps: a) Contacting the shell of an untreated crustacean with a water-soluble aqueous composition; said composition comprising an acid that can form a soluble calcium salt with calcium, wherein said acid is present in the aqueous composition at a concentration of 1% to 5%; b) Maintain contact between the crustacean's shell and the aqueous composition for an appropriate period of time to allow calcium in the crustacean's shell to separate from the shell; c) Expose the crustacean's shell to an alkaline solution; d) Maintain contact between the crustacean's shell and the alkaline solution for an appropriate period of time to allow the oils and proteins on the crustacean's shell to separate from the shell.

2. The application according to claim 1, characterized in that: The shells of the crustaceans that have had their calcium removed are those that have been thoroughly soaked in acid.

3. The application according to claim 1, characterized in that: The crustacean's shell is in contact with the aqueous composition for 12 hours.

4. The application according to claim 1, characterized in that: The acid is one or more of hydrochloric acid, nitric acid, and formic acid.

5. The application according to claim 1, characterized in that: The application also includes: hot pressing a porous adsorbent material after adsorbing nanoplastic particles into a sheet material.

6. A wastewater treatment device, characterized in that: The invention includes a porous adsorbent material, which is the shell of a crustacean with calcium removed, retaining the chitin-based skeleton, and having a rough surface, channels with a pore size of 1-2 μm, and an ordered fiber bundle structure. The porous adsorbent material is prepared by a method comprising the following steps: a) Contacting the shell of an untreated crustacean with a water-soluble aqueous composition; said composition comprising an acid that can form a soluble calcium salt with calcium, wherein said acid is present in the aqueous composition at a concentration of 1% to 5%; b) Maintain contact between the crustacean's shell and the aqueous composition for an appropriate period of time to allow calcium in the crustacean's shell to separate from the shell; c) Expose the crustacean's shell to an alkaline solution; d) Maintain contact between the crustacean's shell and the alkaline solution for an appropriate period of time to allow the oils and proteins on the crustacean's shell to separate from the shell; The wastewater treatment device is used to adsorb nanoplastic particles in water.

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