SYSTEM AND METHOD FOR REMOVING POLYVINYL CHLORIDE (PVC) MICROPLASTICS FROM MEDIUM USING BIOPOLYMER-BASED ADSORBENT MATERIAL

Abstract

A system for removing polyvinyl chloride (PVC) microplastics from medium using biopolymer-based adsorbent material is provided. The system 100 includes a filtration cage 102, and a biopolymer-based adsorbent material. The filtration cage 102 allows the PVC microplastics to enter and prevent PVC microplastics from escaping into medium. The biopolymer-based adsorbent material 104 is placed inside the filtration cage 102 and includes first biopolymer compound, second biopolymer compound, and first cross-linking agent. The first biopolymer compound is mixed with second biopolymer compound to form biopolymer complex that is cross-linked with cross-linking agent to form the biopolymer-based adsorbent material. The biopolymer-based adsorbent material 104 adsorbs the PVC microplastics through ion-dipole interactions between charged functional groups on the adsorbent material 104 and PVC microplastics, when interacting the biopolymer-based adsorbent material 104 with the PVC microplastics under stirring using a magnetic stirrer 108, thereby removing the PVC microplastics from the medium 110. FIG. 1

Specification

Description:BACKGROUND
Technical Field
[0001] The embodiments herein generally relate to a plastic waste management and more particularly, to a system and method for removing polyvinyl chloride (PVC) microplastics from a medium using a biopolymer-based adsorbent material.
Description of the Related Art
[0002] Water pollution has emerged as a pressing global issue, significantly exacerbated by the proliferation of plastic waste. The ubiquitous use of plastic products in daily life has led to an alarming increase in plastic debris in aquatic ecosystems, severely impacting marine life and water quality. Plastics not only persist in the environment for hundreds of years but also break down into smaller particles, known as microplastics, which pose serious threats to aquatic organisms and enter the food chain. This widespread contamination has led to increased attention from researchers and policymakers, who are seeking effective solutions to mitigate the adverse effects of plastic pollution.
[0003] Much of the existing research has primarily focused on the adsorption of heavy metals and other harmful substances associated with water pollution. While this work is vital for addressing specific pollutants, it has also highlighted a significant gap in the understanding of the interactions between microplastics and chemical compounds in the environment. Recent investigations have revealed that certain chemical processes used in bead production can lead to the leaching of toxic substances into aquatic systems, further complicating the ecological impact of plastic waste.
[0004] Accordingly, there remains a need for developing an environmental friendly approach for removing microplastic contamination without any toxicity.
SUMMARY
[0005] In view of the foregoing, an embodiment herein provides a system for removing polyvinyl chloride (PVC) microplastics from a medium. The system includes a filtration cage that is configured to allow the PVC microplastics to enter from the medium and prevent the PVC microplastics from escaping into the medium; and a biopolymer-based adsorbent material that is placed inside the filtration cage. The biopolymer-based adsorbent material includes (i) a first biopolymer compound, (ii) a second biopolymer compound, and (iii) a first cross-linking agent. The first biopolymer compound is mixed with the second biopolymer compound to form a biopolymer complex that is cross-linked with the cross-linking agent to form the biopolymer-based adsorbent material. The biopolymer-based adsorbent material adsorbs the PVC microplastics in the medium due to ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material and the PVC microplastics, when placing the biopolymer-based adsorbent material in the filtration cage and interacting with the PVC microplastics, thereby removing the PVC microplastics from the medium.
[0006] In some embodiments, the first biopolymer compound includes 5%-6% w/w of sodium alginate, and the second biopolymer compound includes 0.05%-0.07% w/w of carrageenan in the biopolymer-based adsorbent material.
[0007] In some embodiments, the cross-linking agent is in a concentration of 4%-5% w/w in the biopolymer-based adsorbent material. The cross-linking agent is calcium chloride.
[0008] In some embodiments, the biopolymer-based adsorbent material includes a second cross-linking agent that is in a concentration of 1%-2% w/w in the biopolymer-based adsorbent material. The second cross-linking agent is chitosan.
[0009] In some embodiments, the biopolymer-based adsorbent material include (i) 6% w/w of sodium alginate, (ii) 0.07% w/w of carrageenan, (iii) 5% w/w of calcium chloride, and (iv) 2% w/w of chitosan.
[0010] In some embodiments, a size of the biopolymer-based adsorbent material is of 2-3 mm in diameter.
[0011] In one aspect, a method of removing polyvinyl chloride (PVC) microplastics in a medium using a biopolymer-based adsorbent material is provided. The method includes (a) synthesizing the biopolymer-based adsorbent material by (i) obtaining a biopolymer solution by dissolving 0.05%-0.07% w/w of a second biopolymer compound in 50 mL of water; (ii) adding 5%-6% w/w of a first biopolymer compound into the biopolymer solution to obtain a complex biopolymer mixture, the complex biopolymer mixture is stirred overnight at 45 °C; (iii) preparing a cross-linking solution by dissolving 4%-5% w/w of a cross-linking agent and 1%-2% w/w a second cross-linking agent in 2 mL of glacial acetic acid; and (iv) dropping the complex biopolymer mixture into the cross-linking solution to obtain the biopolymer-based adsorbent material; (b) placing 0.5%-1% w/w of the biopolymer-based adsorbent material in a filtration cage; (c) positioning the filtration cage including the biopolymer-based adsorbent material to make contact with the medium containing the PVC microplastics; and (iv) subjecting the biopolymer-based adsorbent material in the filter cage to interact with the medium containing the PVC microplastics at a pH of 7 for 60 minutes at room temperature of 25°C under a visible light and stirring at 450 RPM with a magnetic stirrer. The biopolymer-based adsorbent material in the filtration cage adsorb the PVC microplastics in the medium due to ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material and the PVC microplastics, thereby removing the PVC microplastics from the medium.
[0012] In some embodiments, the filtration cage is configured to allow the PVC microplastics to enter from the medium and prevent the PVC microplastics from escaping into the medium.
[0013] In some embodiments, a concentration of the PVC microplastics in the medium includes 0.2 % w/w.
[0014] In some embodiments, a removal rate of the PVC microplastics in the medium by the biopolymer-based adsorbent material is of 94%.
[0015] The biopolymer-based adsorbent material of the present disclosure adsorbs the PVC microplastics in the medium through ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material and the PVC microplastics, when interacting the biopolymer-based adsorbent material with the PVC microplastics, thereby removing the PVC microplastics. As the filtering cage is designed to allow PVC particles to enter while preventing their escape, the system maximizes the contact time between the PVC particles and the biopolymer-based adsorbent material, enhancing the overall efficiency of the PVC removal process. Further, as the biopolymer-based adsorbent material is placed in the filtration cage and the PVC microplastics are agitated, the interaction between the PVC microplastic particles and the biopolymer-based adsorbent material is enhanced, thereby improving a removal rate of the PVC microplastics.
[0016] As derived from natural sources, the biopolymer-based adsorbent material is less likely to leach toxic substances into aquatic systems during production or use, minimizing the ecological impact associated with conventional chemical processes. Further, the biopolymer-based adsorbent material is compatible with living organisms. The components and methods that are used in the system are affordable, making the process economically viable. Further, the method of the present disclosure produces the ready-to-use biopolymer-based adsorbent material that can be easily implemented in filtration systems. Moreover, the biopolymer-based adsorbent material is reusable, providing long-term solutions for PVC microplastic removal, which is practical for continuous applications. Hence, the biopolymer-based adsorbent material of the present disclosure can be used as packing material in a packed bed reactor, making the process scalable for industrial use.
[0017] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[0019] FIG. 1 is a system view that illustrates a system for removing polyvinyl chloride (PVC) microplastics from a medium according to some embodiments herein;
[0020] FIG. 2 is a table view that illustrates ingredients used for synthesizing a biopolymer-based adsorbent material of FIG. 1 according to some embodiments herein;
[0021] FIG. 3 is a flow diagram that illustrates a method of removing polyvinyl chloride (PVC) microplastics in a medium using a biopolymer-based adsorbent material according to some embodiments herein;
[0022] FIG. 4 is an exemplary diagram that illustrates biopolymer-based adsorbent materials according to some embodiments herein;
[0023] FIG. 5 is a graphical representation that illustrates a Fourier-transform infrared (FTIR) spectra of PVC, control NC beads, and test NC beads according to some embodiments herein; and
[0024] FIG. 6 is an exemplary view that illustrates optical images of control NC beads, and test NC beads according to some embodiments herein.
DETAILED DESCRIPTION OF THE DRAWINGS
[0025] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0026] As mentioned, there remains a need for developing an environmental friendly approach for removing microplastic contamination without any toxicity. Various embodiments disclosed herein provide a system and method for removing polyvinyl chloride (PVC) microplastics from a medium using a biopolymer-based adsorbent material. The biopolymer-based adsorbent material of the present disclosure adsorbs the PVC microplastics due to ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material and the PVC microplastics, when interacting the biopolymer-based adsorbent material with the PVC microplastics, thereby removing the PVC microplastics. Further, as the biopolymer-based adsorbent material is placed in a filtration cage and the PVC microplastics are agitated, the interaction between the PVC microplastic particles and the biopolymer-based adsorbent material is enhanced, thereby improving a removal rate of the PVC microplastics.
[0027] Referring now to the drawings, and more particularly to FIGS. 1 through 6, where similar reference characters denote corresponding features consistently throughout the figures, preferred embodiments are shown.
[0028] FIG. 1 is a system view that illustrates a system 100 for removing polyvinyl chloride (PVC) microplastics from a medium according to some embodiments herein. The system 100 includes a filtration cage 102, a biopolymer-based adsorbent material 104, a mechanical stirrer 106, a RPM controller 108, and a medium 110 including PVC microplastics. The system 100 is arranged in a structured manner to remove the PVC microplastics present in the medium 110 using the biopolymer-based adsorbent material 104. The medium 110 may be an aqueous solution, wastewater, or any other fluid containing suspended PVC microplastics.
[0029] The biopolymer-based adsorbent material 104 is made of a first biopolymer compound, a second biopolymer compound, a first cross-linking agent, and a second cross-linking agent. The biopolymer-based adsorbent material 104 may be synthesized using an ionic gelation process. In some embodiments, the first biopolymer compound is mixed with the second biopolymer compound to form a biopolymer complex that is cross-linked with the first and second cross-linking agents to form the biopolymer-based adsorbent material 104. The first biopolymer compound may be sodium alginate, the second biopolymer compound may be carrageenan. The first cross-linking may be calcium chloride, and the second cross-linking agent may be chitosan. The biopolymer-based adsorbent material 104 may be in a form of nanocomposite beads. A size of the biopolymer-based adsorbent material 104 is of 2-3 mm diameter. A surface of the biopolymer-based adsorbent material 104 may include charged functional groups such as carboxyl groups (-COOH), hydroxyl groups (-OH), CH2 stretching, and carbonyl group (C=O).
[0030] The filtration cage 102 may include perforations or mesh to facilitate the flow of medium 110 while preventing the escape of the biopolymer-based adsorbent material 104. In some embodiments, the filtration cage 102 is configured to allow the PVC microplastics to enter from the medium 110 and prevent the PVC microplastics from escaping into the medium 110. The mechanical stirrer 106 is configured to agitate the medium 110 at 450 RPM. The agitation condition (or RPM) may be set through a RPM controller 108.
[0031] When in operation, the biopolymer-based adsorbent material 104 is placed inside the filtration cage 102 and the filtration cage 102 including the biopolymer-based adsorbent material 104 is positioned in such a manner to make contact with the medium 110 containing the PVC microplastics. Upon stirring by the mechanical stirrer 106, the PVC microplastics in the medium 110 efficiently enter into the filtration cage 102 and interact with the biopolymer-based adsorbent material 104 in the filter cage 102. A pH of the medium 110 may be of 7. The PVC microplastics may be interacted with the biopolymer-based adsorbent material 104 for 60 minutes at a room temperature of 25°C, under visible light, and stirring with the magnetic stirrer 106. The biopolymer-based adsorbent material 104 adsorbs the PVC microplastics in the medium 110 through ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material 104 and the PVC microplastics, thereby, removing the PVC microplastics from the medium 110.
[0032] FIG. 2 is a table view that illustrates ingredients used for synthesizing a biopolymer-based adsorbent material 104 of FIG. 1 according to some embodiments herein. The table view includes an ingredients field 202, and a concentration of the ingredients field 204. The ingredients field 202 includes the list of ingredients which are used to synthesize the biopolymer-based adsorbent material 104. The following list of ingredients are used to synthesize the biopolymer-based adsorbent material 104: (a) a first biopolymer compound, (b) a second biopolymer compound (c) a first cross-linking agent, and (d) a second cross-linking agent.
[0033] The concentration of the ingredients field 204 includes a percentage of the ingredients which are used to synthesize the biopolymer-based adsorbent material 104. The percentage of the first biopolymer compound for synthesizing the biopolymer-based adsorbent material 104 may range from 5%-6% weight by weight (w/w). The percentage of the second biopolymer compound for producing the biopolymer-based adsorbent material 104 may range from 0.05%-0.07% w/w. The percentage of the first cross-linking agent for preparing the biopolymer-based adsorbent material 104 may range from 4%-5% w/w. The percentage of the second cross-linking agent for producing the biopolymer-based adsorbent material 104 may range from 1-2 % w/w.
[0034] The first biopolymer compound serves as a base polymer for producing the biopolymer-based adsorbent material 104. The first biopolymer compound provides essential gelation properties and structural integrity to the biopolymer-based adsorbent material 104. The first biopolymer compound may be selected from a group consisting of sodium alginate, agar-agar, gelatin, pectin, or a combination thereof. In some embodiments, the first biopolymer compound is sodium alginate. In some embodiments, the biopolymer-based adsorbent material 104 include the first biopolymer compound in a concentration of 6% w/w.
[0035] The second biopolymer compound enhances the mechanical properties and texture of the biopolymer-based adsorbent material 104, providing additional structural integrity and stability to the biopolymer-based adsorbent material 104. The second biopolymer compound may be selected from a group consisting of carrageenan, pectin, agar-agar, pectin, gelatin, locust bean gum, xanthan gum, or a combination thereof. In some embodiments, the second biopolymer compound is carrageenan. In some embodiments, the biopolymer-based adsorbent material 104 include the second biopolymer compound in a concentration of 0.07% w/w.
[0036] The first cross-linking agent may be added to the biopolymer-based adsorbent material 104 to form a gel matrix, facilitating the cross-linking of biopolymers and stabilizing the bead structure. The first cross-linking agent may be selected from a group consisting of calcium chloride (CaCl₂), potassium chloride (KCl), barium chloride (BaCl₂), ferric chloride, aluminum sulfate, glutaraldehyde or a combination thereof. In some embodiments, the first cross-linking agent is calcium chloride. In some embodiments, the biopolymer-based adsorbent material 104 include the first cross-linking agent in a concentration of 5% w/w.
[0037] The second cross-linking agent may be added to the biopolymer-based adsorbent material 104 to further enhance the mechanical stability and functional properties of the biopolymer-based adsorbent material 104. The second cross-linking agent may interact with the first cross-linking agent and biopolymers through its amino and hydroxyl groups, forming additional covalent and ionic bonds that contribute to the overall integrity, controlled release capabilities, and biocompatibility of the biopolymer-based adsorbent material 104. The second cross-linking agent may be selected from a group consisting of chitosan, glutaraldehyde, genipin, sodium alginate, or a combination thereof. In some embodiments, the second cross-linking agent is chitosan. In some embodiments, the biopolymer-based adsorbent material 104 include the second cross-linking agent in a concentration of 2% w/w.
[0038] In some embodiments, the biopolymer-based adsorbent material 104 includes 5%-6% w/w of the first biopolymer compound, 0.05%-0.07% w/w of the second biopolymer compound, 4%-5% w/w of a first cross-linking agent, and 1-2% w/w of the second cross-linking agent. In some embodiments, the biopolymer-based adsorbent material 104 includes (i) 6% w/w of sodium alginate, (ii) 0.07% w/w of carrageenan, (iii) 5% w/w of calcium chloride, and (iv) 2% w/w of chitosan.
[0039] In some embodiments, the first biopolymer compound is mixed with the second biopolymer compound to form a biopolymer complex that is cross-linked with the cross-linking agent to form the biopolymer-based adsorbent material 104. The biopolymer-based adsorbent material 104 may in a form of nanocomposite beads. The biopolymer-based adsorbent material 104 is in a form of ready-to-use. The biopolymer-based adsorbent material 104 has a size range between 2 to 3 mm in diameter. The biopolymer-based adsorbent material 104 includes charged functional groups capable of forming ion-dipole interactions with the PVC microplastics. In some embodiments, the biopolymer-based adsorbent material 104 adsorbs the PVC microplastics through the ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material 104 and the PVC microplastics.
[0040] The biopolymer-based adsorbent material 104 may be reusable. The shelf-life of the biopolymer-based adsorbent material 104 is about 2 to 3 weeks. The biopolymer-based adsorbent material 104 may have storage stability and storable at ambient condition for a long period of time (i.e. upto 4 weeks)
[0041] FIG. 3 is a flow diagram that illustrates a method of removing polyvinyl chloride (PVC) microplastics in a medium 110 using a biopolymer-based adsorbent material 104 according to some embodiments herein. At step 302, the biopolymer-based adsorbent material 104 is synthesized by (i) obtaining a biopolymer solution by dissolving 0.05%-0.07% w/w of a second biopolymer compound in 50 mL of water; (ii) adding 5%-6% w/w of a first biopolymer compound into the biopolymer solution to obtain a complex biopolymer mixture; (iii) stirring the complex biopolymer mixture overnight at 45 °C; (iv) preparing a cross-linking solution by dissolving 4%-5% w/w of a first cross-linking agent and 1%-2% w/w a second cross-linking agent in 2 mL of glacial acetic acid; and (v) dropping the complex biopolymer mixture into the cross-linking solution to obtain the biopolymer-based adsorbent material 104. In some embodiments, the first biopolymer compound is sodium alginate, a second biopolymer compound is carrageenan, a first cross-linking agent is calcium chloride, and a second cross-linking agent is chitosan.
[0042] At step 304, 0.5%-1% w/w of the biopolymer-based adsorbent material 104 is placed in a filtration cage 102. In some embodiments, the filtration cage 102 is configured to allow the PVC microplastics to enter from the medium 110 and prevent the PVC microplastics from escaping into the medium 110.
[0043] At step 306, the filtration cage 102 including the biopolymer-based adsorbent material 104 is positioned in such a manner to make contact with the medium 110 containing the PVC microplastics. A concentration of the PVC microplastics in the medium 110 includes 2 grams (g) per litter (L).
[0044] At step 308, the biopolymer-based adsorbent material 104 in the filter cage 102 is subjected to interact with the medium 110 containing the PVC microplastics at a pH of 7 for 60 minutes at room temperature of 25°C under a visible light and stirring at 450 RPM with a magnetic stirrer 106.
[0045] At step 310, the PVC microplastics in the medium 110 are adsorbed by the biopolymer-based adsorbent material 104 through ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material 104 and the PVC microplastics, thereby removing the PVC microplastics in the medium. A removal rate of the PVC microplastics in the medium 110 by the biopolymer-based adsorbent material 104 is of 94%.
[0046] FIG. 4 is an exemplary diagram that illustrates biopolymer-based adsorbent materials 104 according to some embodiments herein. In some exemplary embodiments, the biopolymer-based adsorbent materials 104, that is, carrageenan-infused sodium alginate nanocomposite beads are synthesized by (i) combining 0.04 g of carrageenan, at a concentration of 0.8 g/L, in a total volume of 50 mL of water to obtain a carrageenan solution; (ii) adding 7 g of sodium alginate to the carrageenan solution, which is then stirred overnight at 45 °C; (iii) slowly injecting the sodium alginate-carrageenan mixture through a syringe into a cross-linking agent containing 5% w/w of calcium chloride and 2% w/w of chitosan that is dissolved in glacial acetic acid to form the carrageenan-infused sodium alginate nanocomposite beads. The synthesized carrageenan-infused sodium alginate nanocomposite beads are shown in FIG. 4. The carrageenan-infused sodium alginate nanocomposite (NC) beads may be subjected to overnight agitation and then washed five times with deionized water to remove excess materials following cross-linking. Finally, the carrageenan-infused sodium alginate nanocomposite beads are stored at 4 °C in deionized water and air-dried before use.
[0047] In some exemplary embodiments, the synthesized carrageenan-infused sodium alginate NC beads are employed to remove PVC particles as shown in FIG. 1. A filtration cage 102 contains 7.5 g of NC beads, which interact with a 2 g/L PVC solution at pH 7. The mixture is stirred for 60 minutes at room temperature (approximately 25°C) under visible light and agitation using a mechanical stirrer 106. The PVC removal efficacy is assessed.
[0048] An investigation using the NC beads examines the impact of pH changes in the reaction mixture (or medium) on PVC removal. The highest level of removal is achieved at 94.73 ± 0.4% at a pH of 7. The removal efficiency increases with longer contact duration, reaching its maximum at 60 minutes. The maximum percentage of PVC removal (94.73 ± 0.2%) is achieved with 7.5 g/L of NC beads. An increase in adsorbent dosage results in improved removal efficiency, primarily due to the increased availability of reactive sites on the surface of the NC beads. Based on the assessment, the maximum PVC removal rate is determined to be 94.73 ± 0.8% using a pH of 7, a concentration of 7.5 g/L for NC beads, a contact period of 60 minutes, and an initial PVC concentration of 2 g/L.
[0049] FIG. 5 is a graphical representation that illustrates a Fourier-transform infrared (FTIR) spectra of PVC, control NC beads, and test NC beads according to some embodiments herein. In some exemplary embodiments, polyvinyl chloride (PVC), carrageenan-infused sodium alginate nanocomposite beads (NC) beads (control NC beads) as shown in FIG. 4, and PVC that is interacted the carrageenan-infused sodium alginate nanocomposite beads (test NC beads) as shown in FIG. 1 are analyzed using the FTIR spectroscopy. In the graphical representation, wavenumber (in cm-1) values are plotted against the X-axis, and transmittance (%) is plotted against the Y-axis. The graph 502 depicts spectrum of PVC, the graph 504 depicts spectrum of the control NC beads, and the graph 506 depicts spectrum of test NC beads.
[0050] As shown in the graph 502, the spectrum of PVC shows characteristic peaks corresponding to its chemical structure, including C-H stretching and bending vibrations. In contrast, as shown in the graph 504, the control NC beads exhibit their distinct peaks, representative of the functional groups present in the biopolymer matrix. After interaction with PVC, as shown in the graph 506, the test NC beads show peaks similar to those of PVC (as shown in the graph 502), indicating the adsorption of PVC particles onto the NC beads. The presence of these characteristic PVC peaks on the test NC beads confirms the successful adsorption and interaction of PVC with the biopolymer-based adsorbent material. This result is consistent with the high PVC removal efficiency observed in the study.
[0051] FIG. 6 is an exemplary view that illustrates optical images of control NC beads, and test NC beads according to some embodiments herein. In some exemplary embodiments, the surface morphology of the control NC beads, and test NC beads is examined. Image 602 shows the surface morphology of the control NC beads and image 604 show the surface morphology of the test NC beads.
[0052] Upon examination of the optical images shown in FIG. 6, it is observed that the control NC beads (shown in image 602) appear smooth and free from any foreign particles. However, in image 604, the presence of PVC particles is clearly visible on the surface of the test NC beads, as indicated by the red arrows. This confirms the successful adsorption of PVC onto the NC beads. The clear contrast between the control and test NC beads highlights the effectiveness of the NC beads in capturing PVC particles from the medium.
[0053] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications without departing from the generic concept, and, therefore, such adaptations and modifications should be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
, C , Claims:I/We Claim:
1. A system (100) for removing polyvinyl chloride (PVC) microplastics from a medium (110), wherein the system (100) comprising:
characterized in that,
a filtration cage (102) that is configured to allow the PVC microplastics to enter from the medium (110) and prevent the PVC microplastics from escaping into the medium (110); and
a biopolymer-based adsorbent material (104) that is placed inside the filtration cage (102), wherein the biopolymer-based adsorbent material (104) comprises,
a first biopolymer compound,
a second biopolymer compound, and
a first cross-linking agent, wherein the first biopolymer compound is mixed with the second biopolymer compound to form a biopolymer complex that is cross-linked with the cross-linking agent to form the biopolymer-based adsorbent material (104), wherein the biopolymer-based adsorbent material (104) adsorbs the PVC microplastics in the medium (110) due to ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material (104) and the PVC microplastics, when placing the biopolymer-based adsorbent material (104) in the filtration cage (102) and interacting with the PVC microplastics, thereby removing the PVC microplastics from the medium (110).


2. The system (100) as claimed in claim 1, wherein the first biopolymer compound comprises 5%-6% weight by weight (w/w) of sodium alginate, and the second biopolymer compound comprises 0.05%-0.07% w/w of carrageenan in the biopolymer-based adsorbent material (104).


3. The system (100) as claimed in claim 1, wherein the cross-linking agent is in a concentration of 4%-5% w/w in the biopolymer-based adsorbent material (104), wherein the cross-linking agent is calcium chloride.


4. The system (100) as claimed in claim 1, wherein the biopolymer-based adsorbent material (104) comprising a second cross-linking agent that is in a concentration of 1%-2% w/w in the biopolymer-based adsorbent material (104), wherein the second cross-linking agent is chitosan.

5. The system (100) as claimed in claim 1, wherein the biopolymer-based adsorbent material (104) comprise (i) 6% w/w of sodium alginate, (ii) 0.07% w/w of carrageenan, (iii) 5% w/w of calcium chloride, and (iv) 2% w/w of chitosan.


6. The system (100) as claimed in claim 1, wherein a size of the biopolymer-based adsorbent material (104) is of 2-3 mm in diameter.


7. A method of removing polyvinyl chloride (PVC) microplastics in a medium (110) using a biopolymer-based adsorbent material (104), wherein the method comprising:
characterized in that,
synthesizing the biopolymer-based adsorbent material (104) by (i) obtaining a biopolymer solution by dissolving 0.05-0.07% weight by weight (w/w) of a second biopolymer compound in 50 mL of water; (ii) adding 5%-6% w/w of a first biopolymer compound into the biopolymer solution to obtain a complex biopolymer mixture, wherein the complex biopolymer mixture is stirred overnight at 45 °C; (iii) preparing a cross-linking solution by dissolving 4%-5% w/w of a cross-linking agent and 1%-2% w/w a second cross-linking agent in 2 mL of glacial acetic acid; and (iv) dropping the complex biopolymer mixture into the cross-linking solution to obtain the biopolymer-based adsorbent material (104);
placing 0.5%-1% w/w of the biopolymer-based adsorbent material (104) in a filtration cage (102);
positioning the filtration cage (102) comprising the biopolymer-based adsorbent material (104) to make contact with the medium (110) containing the PVC microplastics; and
subjecting the biopolymer-based adsorbent material (104) in the filter cage (102) to interact with the medium (110) containing the PVC microplastics at a pH of 7 for 60 minutes at room temperature of 25°C under a visible light and stirring at 450 RPM with a magnetic stirrer (106), wherein the biopolymer-based adsorbent material (104) in the filtration cage (102) adsorb the PVC microplastics in the medium (110) due to ion-dipole interactions between charged functional groups on the biopolymer-based adsorbent material (104) and the PVC microplastics, thereby removing the PVC microplastics from the medium (110).


8. The method as claimed in claim 7, wherein the filtration cage (102) is configured to allow the PVC microplastics to enter from the medium (110) and prevent the PVC microplastics from escaping into the medium (110).


9. The method as claimed in claim 7, wherein a concentration of the PVC microplastics in the medium (110) comprises 0.2% w/w.


10. The method as claimed in claim 7, wherein a removal rate of the PVC microplastics in the medium (110) by the biopolymer-based adsorbent material (110) is of 94%.


Dated October 28, 2024

Arjun Karthik Bala
(IN/PA 1021)
Agent for Applicant

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