Filtration membrane, method of forming filtration membrane and filtration system

Abstract

A filtration membrane comprising a substantially cylindrical substrate made of a ceramic composition and a graphene-based compound overlaid the substantially cylindrical substrate such that the graphene-based compound adheres to the ceramic composition of the substantially cylindrical substrate and an enhancing agent added to the graphene-based compound or laid over the graphene-based compound onto the membrane to enhance the adhesion of the graphene-based compound to the ceramic composition.

Description

[0001]

[0002] FILTRATION MEMBRANE, METHOD OF FORMING FILTRATION MEMBRANE AND FILTRATION SYSTEM

[0003] TECHNICAL FIELD

[0004] The present disclosure relates generally to the field of water purification systems; and more specifically, to a filtration membrane, a method of forming the filtration membrane and a system for filtration.

[0005] BACKGROUND

[0006] Access to clean, safe water is a fundamental human requirement and a paramount global challenge. As populations grow and industrialization expands, the demand for efficient, cost- effective water purification technologies continues to rise. Water contamination from various sources, including industrial effluents, agricultural runoff, and inadequate sanitation, poses significant risks to human health and environmental sustainability. Consequently, the development of advanced water purification methods has become a priority in both developed and developing regions. Traditional water treatment methods, such as chemical treatment, distillation, and reverse osmosis, while effective, often come with high energy costs, complex infrastructure requirements, or limitations in removing certain contaminants. This has led to a growing interest in membrane-based filtration technologies, which offer potential advantages in efficiency and scalability.

[0007] Currently, ceramic membranes have emerged as a promising solution in the field of water purification. The ceramic membranes are valued for their durability, chemical resistance, and ability to withstand high temperatures and pressures, making them suitable for various industrial and municipal water treatment applications. However, despite their advantages, the ceramic membranes have several limitations, such as limited filtration efficiency, high operating pressures, durability issues in long-term use, fouling and degradation problems and increased energy consumption. For example, the conventional ceramic membranes often require relatively high operating pressures, leading to increased energy consumption and operational costs. While effective for many applications, the conventional ceramic membranes lack the ability for the removal of certain contaminants, particularly at the nanoscale level. Moreover, the conventional ceramic membranes can experience fouling over long term of use, where contaminants accumulate on the membrane surface, reducing filtration efficiency and necessitating frequent cleaning or replacement. The operational lifespan of the conventional ceramic membranes can be limited by wear and tear, especially in harsh environments, leading to increased maintenance requirements and replacement costs. Therefore, there exists a technical problem of an inefficient filtration membrane for water purification having limited filtration efficiency, high operating pressures, durability issues in long-term use, fouling and degradation problems and increased energy consumption.

[0008] Therefore, in light of the foregoing discussion there exists a need to overcome the aforementioned drawbacks associated with the conventional filtration membranes used for water purification.

[0009] SUMMARY

[0010] The present disclosure provides a filtration membrane, a method of forming the filtration membrane and a system for filtration. The present disclosure provides a solution to the existing problem of an inefficient filtration membrane for water purification having limited filtration efficiency, high operating pressures, durability issues in long-term use, fouling and degradation problems and increased energy consumption. An aim of the present disclosure is to provide a solution that overcomes at least partially the problems encountered in prior art, and provide an improved filtration membrane, a method of forming the improved filtration membrane and a system for filtration.

[0011] The object of the present disclosure is achieved by the solutions provided in the enclosed independent claims. Advantageous implementations of the present disclosure are further defined in the dependent claims.

[0012] According to an aspect of the present disclosure, there is provided a filtration membrane comprising a substantially cylindrical substrate made of a ceramic composition, a graphenebased compound overlaid the substantially cylindrical substrate such that the graphene-based compound adheres to the ceramic composition of the substantially cylindrical substrate and an enhancing agent added to the graphene-based compound or laid over the graphene -based compound onto the membrane to enhance the adhesion of the graphene-based compound to the ceramic composition.

[0013] The disclosed filtration membrane results in a combination of the ceramic substrate (i.e., the substantially cylindrical substrate) with the graphene-based compound, such as graphene oxide, leading to an enhanced filtration performance and durability. The filtration membrane may also be referred to as an ultra-energy efficient ceramic membrane with improved durability. The use of graphene oxide enhances water filtration efficiency of the filtration membrane. The filtration membrane can operate at ultra-low pressures, for example, 0.4 to 4 bar, preferably under 2 bar, while maintaining excellent filtration performance. The combination of the ceramic substrate with graphene-based compound resolves the technical issue of having limited filtration efficiency, operating at high pressures, durability issues in long-term use, fouling and degradation problems and increased energy consumption of conventional filtration membranes. The filtration membrane may have a variety of applications, such as water purification for domestic and industrial use, wastewater treatment, food and beverages industries, desalination plants, chemical, semiconductor, and pharmaceutical filtration systems, and the like. In addition to aforementioned application areas, the filtration membrane may also be used for gases and dairy filtration applications.

[0014] In an implementation form, the ceramic composition comprises one or more of oxide ceramics, non-oxide ceramics, silicate ceramics, and composite ceramics.

[0015] The ceramic composition comprising one or more of oxide ceramics, non-oxide ceramics, silicate ceramics, and composite ceramics offers a combination of high mechanical strength, thermal stability, and chemical resistance, making the filtration membrane suitable for a wide range of demanding applications.

[0016] In a further implementation form, the graphene-based compound is either graphene oxide or reduced graphene oxide.

[0017] The use of graphene oxide or the reduced graphene oxide offers a range of advantages, including high surface area and permeability, excellent chemical stability, mechanical strength, tunability for selective filtration, hydrophilicity, antibacterial properties, and scalability for industrial production.

[0018] In a further implementation form, the graphene oxide is spray coated over the substantially cylindrical substrate.

[0019] The spray coating of graphene oxide over the ceramic substrate offers significant advantages in terms of uniform coverage, scalability, control over coating thickness, minimal waste, and compatibility with the ceramic substrate. In an alternate implementation, the graphene oxide is dip coated over the substantially cylindrical substrate.

[0020] In a further implementation form, the enhancing agent is a fluid-permeable protective coating laid over the graphene-based compound on the substantially cylindrical substrate.

[0021] The coating of the protective permeable layer (such as epoxy) ensures durability of the filtration membrane and reduces the requirement for frequent replacements of the filtration membrane.

[0022] In a further implementation form, the protective coating is epoxy or a polymer-based thin layer.

[0023] The polymer-based thin layer provides a flexible yet durable protective layer, for protecting membrane formed of materials such as graphene oxide or ceramic substrates. This prevents damage due to abrasion, chemical attack, or fouling.

[0024] In a further implementation form, the enhancing agent is a cross-linking agent laid over the graphene-based compound on the substantially cylindrical substrate.

[0025] The coating of the cross-linking agent over the graphene-based compound leads to an improved adhesion and durability of the graphene-based compound to the ceramic substrate and maintain the structural integrity of the filtration membrane during operation.

[0026] In another aspect, the present disclosure provides a system for filtration comprising an inlet for taking in a fluid to be filtered, a first outlet for collecting filtered fluid, a second outlet for collecting retentate fluid, a housing disposed between the inlet and the first and the second outlets, where the housing comprises a filtration membrane.

[0027] The system of filtration comprises the filtration membrane comprising the ceramic substrate with an advanced graphene-based compound (i.e., graphene oxide). This combination offers superior mechanical strength, chemical resistance, and anti-fouling properties compared to conventional fdtration membranes.

[0028] In a yet another aspect, the present disclosure provides a method of forming a filtration membrane comprising the steps of forming a substantially cylindrical substrate from a ceramic composition, coating the substantially cylindrical substrate with a graphene-based compound and drying the coated membrane to durably adhere the graphene-based compound to the ceramic composition of the substantially cylindrical substrate.

[0029] The method achieves all the advantages and technical effects of the filtration membrane of the present disclosure.

[0030] It is to be appreciated that all the aforementioned implementation forms can be combined.

[0031] It has to be noted that all devices, elements, circuitry, units and means described in the present application could be implemented in hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective hardware elements, or any kind of combination thereof. It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.

[0032] Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative implementations construed in conjunction with the appended claims that follow.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those skilled in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.

[0035] Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:

[0036] FIG. 1A illustrates a filtration membrane, in accordance with an embodiment of the present disclosure;

[0037] FIG. IB depicts a ceramic substrate of a filtration membrane, in accordance with an embodiment of the present disclosure;

[0038] FIG. 2 illustrates a system for filtration, in accordance with an embodiment of the present disclosure; and

[0039] FIG. 3 is a flowchart of a method of forming a filtration membrane, in accordance with an embodiment of the present disclosure.

[0040] In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the nonunderlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.

[0041] DETAILED DESCRIPTION OF EMBODIMENTS

[0042] The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.

[0043] FIG. 1A illustrates a filtration membrane, in accordance with an embodiment of the present disclosure. With reference to FIG. 1A, there is shown a filtration membrane 100 comprising a substantially cylindrical substrate 102 and a graphene-based compound 104. The filtration membrane 100 further comprises an enhancing agent (not visible in FIG. 1A) added to the graphene-based compound 104 or laid over the graphene-based compound 104 onto the membrane to enhance the adhesion of the graphene-based compound 104 to the ceramic composition.

[0044] The filtration membrane 100 may be referred to as a selective barrier that allows certain substances, like water molecules, to pass through while blocking others, such as contaminants and impurities. The filtration membrane 100 is designed to purify water by removing particles, microorganisms, and dissolved substances through various physical and chemical processes. The filtration membrane 100 can vary in material and structure, such as thin film composite membranes, ceramic membranes, or polymeric membranes like reverse osmosis membranes. In the present disclosure, the filtration membrane 100 corresponds to a ceramic membrane.

[0045] The filtration membrane 100 comprises the substantially cylindrical substrate 102 made of a ceramic composition. The ceramic composition typically exhibits high porosity, enabling efficient water filtration. The ceramic compositions are highly resistant to chemical degradation (e.g., from acids or bases) and can withstand high temperatures, making the filtration membrane 100 suitable for demanding filtration environments. The ceramic composition generally has high compressive strength, making the filtration membrane 100 more robust and durable under high-pressure filtration conditions. The cylindrical shape is a common geometry for ceramic membrane supports. The cylindrical shape offers several advantages, such as maximizes surface area to volume ratio, allows for efficient water flow and provides structural stability. The substantially cylindrical substrate 102 may also be referred to as a ceramic substrate. The standard size of the ceramic substrate can vary depending on the application, industry, and specific manufacturer. However, there are common standard sizes used for various purposes in water filtration. The standard sizes include diameter in the range of 20 mm to 60 mm and length in the range of 300 mm to 2000 mm for tubular substrates These sizes ensure compatibility with specific equipment or systems. Preferably, the standard size of the ceramic substrate is 1200 mm x 41 mm.

[0046] In an implementation, the ceramic composition comprises one or more of oxide ceramics, non-oxide ceramics, silicate ceramics, and composite ceramics. The various ceramic compositions are used for the substantially cylindrical substrate 102 in the filtration membrane 100, where each ceramic composition offers unique properties suitable for different applications. The choice of the ceramic composition depends on the specific requirements of a filtration process, including chemical environment, temperature, and mechanical stress. The oxide ceramics is the most common type of ceramic composition used in filtration membranes. Examples of the oxide ceramics may include, but are not limited to, Aluminum Oxide (AI2O3), Iron Oxide (Fe2O3, Fc^Oi). Yttria (Y2O3), Zirconium Dioxide (Zr02), Titanium Dioxide (Ti02), and the like. These oxide ceramics are known for their high thermal stability, excellent chemical resistance, and mechanical strength.

[0047] Preferably, in an implementation scenario, the ceramic composition comprises Aluminum Oxide (AI2O3) and Zirconium Dioxide (Zr02). In said ceramic composition, the ceramic substrate is made of Aluminum Oxide (AI2O3) coated with a selective layer of Zirconium Dioxide (Zr02). The Aluminum Oxide (AI2O3) may also be referred to as Alumina. The Zirconium Dioxide (Zr02) may also be referred to as Zirconia. Alternatively, may be stated as, the selective layer of Zirconia (Zr02) or Zirconium is added to the substantially cylindrical substrate 102 made of Alumina (AI2O3). The ceramic composition of Alumina (AI2O3) and Zirconia (Zr02) results in a highly durable, chemically resistant, and thermally stable composite material with excellent mechanical strength and low fouling tendencies, making the combination ideal for high-performance filtration membranes (i.e., the filtration membrane 100).

[0048] Preferably, in another implementation scenario, the ceramic composition comprises Aluminum Oxide (AI2O3) and Titanium Dioxide (Ti02). In said ceramic composition, the ceramic substrate is made of Alumina (AI2O3) coated with a selective layer of Titanium Dioxide (Ti02). The Titanium Dioxide (Ti02) may also be referred to as Titania. The combination of Alumina (AI2O3) and Titania (Ti02) in the ceramic composition of the substantially cylindrical substrate 102 results in a high-performance material with advantages, such as improved mechanical strength, enhanced filtration performance, photocatalytic activity, chemical resistance, thermal stability, and lower fouling rates. These properties make the Alumina-Titania composite ideal for a wide range of filtration applications, from water purification to industrial wastewater treatment, while also offering long-term operational efficiency and cost savings.

[0049] Optionally, the non-oxide ceramic composition includes carbides, for example, Silicon Carbide (SiC) and Nitrides (SiN), for example, Silicon Nitride (SisN^. The non-oxide ceramics are highly durable and resistant to extreme chemical environments. The non-oxide ceramics offer superior performance in corrosive and high-temperature environments compared to the oxide ceramics. For example, the Silicon Carbide (SiC) membranes have been shown to exhibit flux rates up to, for example, 50%, higher than Alumina under comparable conditions due to their lower surface fouling properties.

[0050] Preferably, in an implementation scenario, the ceramic composition comprises Silicon Carbide (SiC). The ceramic composition comprising the Silicon Carbide (SiC) offers several key advantages, such as outstanding mechanical strength, superior chemical resistance, excellent thermal stability, high permeability, reduced fouling, and long operational life. The aforementioned properties make the Silicon Carbide (SiC) highly suitable for filtration systems in harsh environments, including water and wastewater treatment, and industrial processes requiring chemical resistance.

[0051] Optionally, the silicate ceramics used in the ceramic composition of the substantially cylindrical substrate 102 include Silica (Si02) and its compounds. The silicate ceramics may include, but are not limited to, common silicate materials, such as Silica (Si02), Mullite (3A12O3-2SiO2), and the like. The silicate materials are known for their good thermal insulation properties and chemical stability. Silica is widely used in the fabrication of porous membranes for filtration due to its chemical inertness. The silica-based membranes offer excellent permeability and selectivity in gas and liquid separations. Moreover, the silicate ceramics are often used in specific filtration applications requiring both chemical and thermal resistance.

[0052] Optionally, the composite ceramics often involve the blending of different ceramic materials to improve mechanical strength, reduce brittleness, or enhance filtration performance. For instance, combining Alumina and Titania can improve strength and surface properties of the filtration membrane 100. The composite membranes offer improved overall performance compared to single-phase ceramics. For example, an Alumina-Titania composite membrane can have improved chemical resistance and reduced fouling, enhancing durability in longterm fdtration operations.

[0053] The fdtration membrane 100 further comprises the graphene-based compound 104 coated over the substrate such that the graphene -based compound 104 adheres durably with the ceramic composition of the substrate. The graphene-based compound 104 is coated over the substantially cylindrical substrate 102 (i.e., the ceramic substrate) having the ceramic composition in such a way that the coating of the graphene -based compound 104 increases the durability of the fdtration membrane 100 without compromising the fdtration efficiency.

[0054] Preferably, the graphene-based compound 104 is either graphene oxide or reduced graphene oxide. The graphene-based compound 104 composed of either graphene oxide or reduced graphene oxide offers a range of advantages, including high surface area and permeability, excellent chemical stability, mechanical strength, tunability for selective fdtration, hydrophilicity, antibacterial properties, and scalability for industrial production. These properties make the graphene oxide highly suitable for applications in fdtration membranes, coatings, sensors, and advanced composite materials.

[0055] Graphene oxide or reduced graphene oxide can be coated over the substantially cylindrical substrate 102 (i.e., the ceramic substrate) using various coating methods, each coating method offers specific advantages in terms of coating uniformity, adhesion, and scalability. The various methods used for depositing the graphene oxide over the ceramic substrate may include, but are not limited to, dip coating, spray coating, spin coating, layer-by-layer coating, electrophoretic deposition, drop casting, chemical vapour deposition, vacuum fdtration deposition, and the like. The choice of coating method depends on the specific requirements of an application, such as desired coating thickness, substrate shape, production scale, and material properties.

[0056] Preferably, the graphene oxide in a fluid form is spray coated over the substantially cylindrical substrate 102. The spray coating of graphene oxide over the substantially cylindrical substrate 102 (i.e., the ceramic substrate) offers significant advantages in terms of uniform coverage, scalability, control over coating thickness, minimal waste, and compatibility with the ceramic substrate. Additionally, the spray coating is an affordable and efficient technique that provides good adhesion, low-temperature processing, and environmentally friendly coating capabilities. These advantages make the spray coating an ideal choice for a wide range of industrial and research applications. Alternatively, a powdered or a semi-liquid paste of graphene oxide may be used for coating the ceramic substrate.

[0057] In one implementation, the substantially cylindrical substrate 102 has multiple channels extending longitudinally along the length of the substrate. In another implementation, the substantially cylindrical substrate 102 is a hollow tubular structure. The diameter of the substantially cylindrical substrate 102 is in the range of 20 mm to 60 mm. In industrial fdtration systems, ceramic membranes (i.e., the fdtration membrane 100 comprising the substantially cylindrical substrate 102) typically have diameter in the range of 40 mm to 60 mm, depending on the application. These sizes are ideal for use in water treatment plants, gas separation, and chemical filtration processes. The cylindrical ceramic membrane with 40 mm to 60 mm diameter allows for easy integration into filtration systems that require high flow rates and mechanical durability. Moreover, tubular ceramic membranes for microfiltration and ultrafiltration are often produced with diameters in the range of 40 mm to 60 mm to optimize surface area for filtration, balancing permeability with mechanical strength. The substantially cylindrical substrate 102 (i.e., the ceramic substrate) having the diameter in the range of 30 mm to 60 mm is commonly used across various industries for applications in filtration, catalysis, and industrial processes. The given diameter range provides an optimal balance between mechanical strength, surface area, and ease of integration into different systems, such as membrane filtration modules, catalytic converters, and industrial reactors.

[0058] The filtration membrane 100 further comprises the enhancing agent (not visible in FIG. 1A) added to the graphene-based compound 104 or laid over the graphene -based compound 104 onto the membrane to enhance the adhesion of the graphene-based compound 104 to the ceramic composition. The primary function of the enhancing agent is to improve the adhesion between the graphene-based compound 104 and the ceramic substrate. The enhancing agent enhances the durability and performance of the filtration membrane 100. In an implementation scenario, the enhancing agent may be mixed with the graphene-based compound 104 before application to the ceramic substrate. This method ensures thorough integration of the enhancing agent throughout the graphene-based compound 104. In another implementation scenario, the enhancing agent can be applied as a separate layer on top of the already -applied graphene-based compound 104. This method can create a gradient of adhesion-promoting properties. The enhancing agent may form covalent bonds between the graphene-based compound 104 and the ceramic substrate. The enhancing agent may create a network structure that interlocks with both the graphene -based compound 104 and the ceramic substrate. Moreover, the enhancing agent may alter the surface properties of either the graphene-based compound 104 or the ceramic substrate to increase compatibility.

[0059] Optionally, the enhancing agent is a fluid-permeable protective coating laid over the graphene-based compound 104 on the substantially cylindrical substrate 102. The protective coating corresponds to a protective permeable coating, such as epoxy on top of graphene oxide to enhance the durability of the filtration membrane 100 while reducing wear and tear and fouling issues. Conventionally, finding a material that is permeable enough to allow water filtration but protective enough to increase lifespan is a technical challenge. But the use of epoxy and other permeable polymer coating solved this technical challenge. While graphene oxide layer (i.e., the graphene-based compound 104) is known for its excellent mechanical and chemical properties, the graphene oxide is also prone to oxidative degradation and fouling, especially in water filtration and harsh chemical environments. Therefore, the coating of the protective layer over the graphene oxide prevents aforementioned issues, and consequently, extend the lifespan of the filtration membrane 100. The protective coating must be fluid-permeable to ensure that the filtration function of the graphene-based compound 104 is not hindered. The materials like polyvinyl alcohol (PVA), polydopamine, or silica-based coatings are often used to provide such balance of protection and permeability.

[0060] Optionally, the protective coating is epoxy or a polymer-based thin layer. The protective coating may correspond to a polyurethane coating, silicon-based coating, or other permeable polymer-based material coating, etc., which can enhance the robustness of the filtration membrane 100 for long term of use. The polymer-based thin layer provides a flexible yet durable protective layer, for protecting delicate membrane layers like graphene oxide or ceramic substrates. This prevents damage due to abrasion, chemical attack, or fouling. The polymer-based thin layer is designed to be thin and fluid-permeable, allowing water, gases, or other fluids to pass through while protecting the underlying filtration layers from contaminants. Polymers like, Polyethylene Glycol (PEG), Polyvinyl Alcohol (PVA) and Polydopamine (PDA) are widely used for their ability to resist fouling, meaning fewer particles or bacteria adhere to the membrane surface, reducing maintenance requirements and increasing the membrane's (i.e., the fdtration membrane 100) operational life. Many polymer-based thin layers, such as PDA or PVA, offer good resistance to chemical degradation in harsh environments, making the polymer-based thin layer suitable for applications like, wastewater treatment or chemical processing. The polymer coatings can be easily applied through various methods, such as spray coating, dip coating, or layer-by- layer assembly, making the polymer coating versatile and cost-effective for large-scale membrane production.

[0061] In a further implementation form, the enhancing agent is a cross-linking agent laid over the graphene-based compound 104 on the substantially cylindrical substrate 102.

[0062] In an implementation, when coating membranes made from graphene or graphene oxide (GO), the enhancing agent including crosslinking agents are used to enhance the stability, mechanical strength, and chemical properties of the membrane. Crosslinking agents bond with graphene oxide to create a networked structure that improves the performance of the membrane in various applications such as fdtration, gas separation, or water treatment. The choice of crosslinking agent depends on the desired properties of the final material, such as hydrophilicity, chemical resistance, or mechanical strength. Epoxy-based crosslinkers, such as Diglycidyl Ether of Bisphenol A (DGEBA), Ethylene Glycol Diglycidyl Ether (EGDGE), Glycidyl Methacrylate (GMA), and Epichlorohydrin, can be effectively used to enhance the mechanical strength and chemical resistance of graphene oxide membranes. The process involves dispersing GO in a suitable solvent, mixing with the epoxy crosslinker, and initiating a crosslinking reaction through heating or UV curing to form covalent bonds between the epoxy groups and the functional groups on the GO surface. The crosslinked GO-epoxy mixture is then cast or coated onto a substrate and further cured to form a durable, chemically resistant membrane, ideal for applications in water filtration and gas separation.

[0063] In another embodiment, the enhancing agent may comprise a non-polymeric coupling molecule, such as an organosilane (for example, 3-aminopropyltriethoxysilane (APTES) or 3-glycidoxypropyltrimethoxysilane (GLYMO)), which forms covalent bonds with both the ceramic surface and functional groups of the graphene-based layer. Alternatively or additionally, the enhancing agent may comprise a cationic surfactant such as cetyltrimethylammonium chloride (CTAC), which electrostatically interacts with the graphene surface and provides affinity for negatively charged and hydrophobic contaminants, including per- and polyfluoroalkyl substances (PFAS). To reduce leaching, such agents may be immobilized through covalent grafting or by encapsulation beneath a thin non-polymeric protective overlayer, for instance an inorganic silica or alumina film.

[0064] Optionally, the pore size of ceramic substrates typically ranges from nanometers (nm) to micrometers (pm), depending on the specific application. In microfiltration, pore sizes range from 100 nm to 10,000 nm, for ultrafiltration, the range is 2 nm to 100 nm.

[0065] Preferably, pore size ofthe substantially cylindrical substrate 102 (i.e., the ceramic substrate) is in the range of 50 nm to 200 nm. The pore size range of 50 nm to 200 nm of the substantially cylindrical substrate 102 (i.e., the ceramic substrate) is ideal for applications in filtration, catalysis, and gas separation, where a balance between permeability and selective separation is crucial. This pore size range allows high flow rates and efficient contaminant removal, while maintaining the mechanical strength, chemical resistance, and durability of ceramic materials, making the filtration membrane 100 suitable for a variety of industrial and environmental uses.

[0066] Preferably, the pore size of the membrane with graphene oxide is in the range of 0. 1 to 2 nm. The filtration membrane 100 can be implemented in cylindrical structures and multi-channel cylindrical structures, with pore size ranging from 0.1 nm to 2 nm.

[0067] FIG. IB depicts a ceramic substrate of a filtration membrane, in accordance with an embodiment of the present disclosure. FIG. IB is described in conjunction with elements from FIG. 1A. With reference to FIG. IB, there is shown the substantially cylindrical substrate 102 of the filtration membrane 100. The graphene -coated membrane has a pore size, preferably, in the range of 0.1 nm to 6 nm, more specifically between 0. 1 nm and 2 nm.

[0068] Thus, the filtration membrane 100 results in a combination of the ceramic substrate (i.e., the substantially cylindrical substrate 102) with graphene oxide and the enhancing agent coatings, leading to enhanced both filtration performance and durability. The combination further results in a highly efficient filtration membrane (i.e., the filtration membrane 100) capable of operating under ultra-low pressures while providing excellent filtration capabilities. The filtration membrane 100 may also be referred to as an ultra-energy efficient ceramic membrane with improved durability. The use of graphene oxide enhances water filtration efficiency, while the addition of the protective permeable layer (such as epoxy) ensures longevity and reduces the requirement for frequent replacements. The filtration membrane 100 can operate at ultra-low pressures, for example, 0.4 to 4 bar while maintaining excellent filtration performance. The combination of the ceramic substrate (i.e., the substantially cylindrical substrate 102) with graphene oxide and permeable protective coatings resolves the technical issue of having limited filtration efficiency, operating at high pressures, durability issues in long-term use, fouling and degradation problems and increased energy consumption of conventional filtration membranes.

[0069] Moreover, the filtration membrane 100 contributes to the technology domain of advanced water filtration by integrating nanotechnology (i.e., graphene oxide layer at nanoscale) with the ceramic substrate (i.e., the substantially cylindrical substrate 102) resulting in a reduced energy consumption, and enhanced longevity. The filtration membrane 100 may have a variety of applications, such as water purification for domestic and industrial use, wastewater treatment, food and beverages industries, desalination plants, chemical and pharmaceutical filtration systems, and the like. In addition to aforementioned application areas, the filtration membrane 100 may also be used for gases and dairy filtration applications.

[0070] FIG. 2 illustrates a system for filtration, in accordance with an embodiment of the present disclosure. FIG. 2 is described in conjunction with elements from FIGs. 1A and IB. With reference to FIG. 2, there is shown a system 200 for filtration comprising an inlet 202, a first outlet 204, a second outlet 206 and a housing 208 disposed between the inlet 202, the first outlet 204 and the second outlet 206. The housing 208 comprises the filtration membrane 100 (of FIG. 1A).

[0071] The inlet 202 is designed to introduce the fluid, i.e., water, being required to be filtered by the system 200. The fluid may contain particles, solutes, or contaminants which require to be separated or removed through the filtration process. The inlet 202 is positioned in such a way to the system 200 to ensure that the unfiltered feed fluid flows tangentially into the housing 208 where the filtration membrane 100 such that it passes through the channels formed in the substrate 102. The inlet 202 is often a tube or port connected to the housing 208 of the filtration system. The inlet 202 may be equipped with connectors, seals, or valves to ensure a secure and leak-free connection with the fluid source. The inlet 202 is generally made from corrosion-resistant materials like stainless steel, polymer, or PVC, depending on the application and the nature of the fluid (e.g., chemical compatibility, temperature, pressure). Once the fluid enters through the inlet 202, the fluid flows into the filtration membrane 100, where it is subjected to filtration by the filtration membrane 100 using the principle of tangential flow or crossflow filtration. The active filtration layer with graphene has pores that blocks small organic molecules, salts, and ions while allowing water to pass through. The fraction of the liquid that passes through the filtration membrane 100 and contains the smaller molecules, such as water or dissolved ions, is referred to as permeate. The portion of the feed that does not pass through the filtration membrane 100, containing larger particles, bacteria, or other contaminants, is referred to as retentate. The tangential flow of the feed solution helps prevent clogging by continuously sweeping larger particles away from the membrane surface, reducing fouling and maintaining a higher filtration rate.

[0072] The first outlet 204 is designed for collecting filtered fluid, i.e. permeate. The first outlet 204 in the system 200 for filtration corresponds to an exit point for collecting the filtered fluid (also known as the permeate). The first outlet 204 is specifically designed to collect and discharge the fluid that has successfully passed through the filtration membrane 100. The filtered fluid is free from contaminants, particles, or solutes, depending on the filtration process (microfiltration, ultrafiltration, nanofiltration, and the like). The first outlet 204 is usually a tube, port, or nozzle that is designed to handle the permeate flow. The diameter and design of the first outlet 204 depend on the volume of filtered fluid being handled by the system 200. The first outlet 204 is often made from the same material as the inlet 202 or the housing 208, such as stainless steel, polymers (PVC, polypropylene), or ceramic, to ensure compatibility with the filtered fluid and resistance to corrosion or wear. The flow rate through the first outlet 204 is dependent on the type of filtration system and the permeability of the filtration membrane 100. In some filtration systems, a valve or flow controller is attached to the first outlet 204 to regulate the pressure and flow rate of the filtered fluid, ensuring that the filtered fluid is discharged at a controlled rate without disrupting the filtration process. The fluid exiting through the first outlet 204 is the filtered fluid, meaning it has passed through the pores of the filtration membrane 100. The quality of the permeate depends on the pore size of the filtration membrane 100 (more specifically, the pore size of the ceramic substrate) and the type of contaminants being filtered out. Moreover, the size of the first outlet 204 is optimized to allow smooth and uninterrupted flow of the filtered fluid, ensuring that the system 200 does not encounter backpressure or blockages.

[0073] The second outlet 206 is designed for collecting retentate fluid. The second outlet 206 is designed to discharge the retentate fluid that contains the concentrated solutes, particles, or contaminants retained by the filtration membrane 100. In many systems, the retentate can be disposed of, recirculated for further filtration, or processed separately. The second outlet 206 is positioned after the membrane filtration process, usually at the opposite end of the system from the first outlet 204. The second outlet 206 is typically a port, valve, or nozzle designed to handle the concentrated fluid that remains after filtration. The materials used for the second outlet 206 depend on the nature of the retentate. For example, if the fluid contains aggressive chemicals or high levels of contaminants, the second outlet 206 would be made of corrosion-resistant materials, such as stainless steel, ceramics, or chemically resistant polymers. The size of the second outlet 206 is generally proportional to the volume and viscosity of the retentate. The second outlet 206 should be wide enough to prevent clogging or blockage caused by the concentrated particles. In some systems, the second outlet 206 allows for a continuous flow of retentate fluid as the filtration process continues. In other systems, the second outlet 206 may discharge intermittently or be manually controlled to release the concentrated fluid at specific intervals. The second outlet 206 can be connected to other equipment or piping systems for transporting the retentate to its next destination, whether the retentate can be subjected for further treatment, disposal, or reuse.

[0074] The housing 208 is disposed between the inlet 202 and the first outlet 204 and the second outlet 206, where the housing 208 comprises the filtration membrane 100. The filtration membrane 100 corresponds to a nanocomposite membrane comprising a nanomaterial (for example, graphene oxide) sprayed or layered over the ceramic substrate (i.e., the substantially cylindrical substrate 102). The filtration membrane 100 is has been described in detail, for example, in FIGs. 1A and IB.

[0075] The housing 208 is designed to encase the filtration membrane 100 and create a controlled pathway for the unfiltered fluid (feed) to pass through the filtration membrane 100 and separate into the permeate (filtered fluid) and retentate (concentrated fluid). The housing 208 protects the filtration membrane 100 from external damage and maintain the system’s pressure and flow characteristics during filtration. The housing 208 is typically positioned between the inlet 202 (for unfiltered fluid) and the two outlets (i.e., the first outlet 204 and the second outlet 206) for permeate and retentate, respectively. The housing 208 is typically cylindrical, though its shape can vary depending on the system’s design and application. The housing 208 may consist of multiple layers or compartments to facilitate different stages of filtration. The housing 208 is made from durable, corrosion-resistant materials, such as stainless steel, polymer composites, ceramics, or PVC, chosen based on the fluid being filtered and the operational conditions, such as pressure, temperature, chemical compatibility. The housing 208 provides structural support for the filtration membrane 100, ensuring that the filtration membrane 100 remains stable and does not collapse or deform under pressure.

[0076] The system 200 for filtration supports tangential filtering, also known as cross-flow filtration. The tangential filtering is a method of filtration in which the fluid (containing suspended particles or solutes) flows tangentially across the surface of the filtration membrane 100, rather than perpendicularly to the filtration membrane 100. The tangential filtering is commonly used in industries such as, water treatment, biotechnology, food processing, and pharmaceuticals for separating solids from liquids, concentrating substances, or clarifying fluids. In the tangential filtration, a feed stream flows tangentially to the surface of the filtration membrane 100. This is different from traditional dead-end filtration, where the feed stream flows directly into the membrane. As the fluid passes tangentially over the filtration membrane 100, a portion of the fluid (i.e., the filtrate or permeate) is drawn through the membrane pores, while the rest (i.e., the retentate or concentrate) continues to flow across the filtration membrane 100, carrying away larger particles. The filtration membrane 100 used in tangential filtering can vary in pore size depending on the desired filtration level. The membrane 100 has a pore size ranging from 0.1 nm to 6 nm, preferably between 0.1 nm and 2 nm (ideal for nanofiltration) for separating smaller molecules like salts and sugars and offers advantages like reduced fouling, continuous operation, and higher flow rates. The tangential filtering is widely used in various industries for purification, concentration, and clarification of fluids. The tangential filtering is particularly beneficial when large amounts of fluid required to be processed with minimal downtime and membrane maintenance.

[0077] Typical water filtration systems (for example, reverse osmosis (RO) systems) use polymeric membranes, such as thin-film composite (TFC) membranes made from materials like polyamide. These membranes are effective but requires higher operating pressure, thereby making them less energy efficient. Moreover, typical RO membranes are less durable and more susceptible to fouling, chemical degradation, and thermal limitations. Therefore, they require frequent servicing (chemical washing) and replacing. In contrast to the conventional water filtration systems, the system 200 of filtration comprises the filtration membrane 100 comprising the ceramic substrate with an advanced graphene -based compound (i.e., graphene oxide). Such a membrane can operate at lower working pressure, thereby making it more energy efficient. In addition, it offers superior mechanical strength, chemical resistance, and anti-fouling properties compared to conventional membranes. The use of graphene enhances selectivity, reduces fouling, and potentially provides additional functional properties like antimicrobial activity.

[0078] FIG. 3 is a flowchart of a method of forming a filtration membrane, in accordance with an embodiment of the present disclosure. FIG. 3 is described in conjunction with elements from FIGs. 1A, IB and 2. With reference to FIG. 3, there is shown a method 300 of forming the filtration membrane 100 (of FIG. 1A). The method 300 comprises the steps 302 to 306.

[0079] There is provided the method 300 of forming the filtration membrane 100.

[0080] At step 302, the method 300 comprises forming a substantially cylindrical substrate from a ceramic composition. The substantially cylindrical substrate 102 (of FIG. 1A) is formed from the ceramic composition. The ceramic materials, such as Alumina (AI2O3), Zirconia (ZrCh). Silicon carbide (SiC), or Titania (Ti O2) are commonly used in forming substrates due to their excellent mechanical strength, chemical resistance, thermal stability, and durability. The aforementioned ceramic materials can be processed into various shapes, including cylindrical substrates, through common ceramic manufacturing techniques, such as extrusion, pressing, or casting. For example, in the extrusion process, the ceramic powder is mixed with a binder to form a plasticized mixture. This mixture is then forced through a die with a circular opening to create a cylindrical shape. The extruded cylinder is cut to the desired length, dried, and then fired at high temperatures to achieve the final solid ceramic form. This process is ideal for creating uniform, continuous cylindrical shapes with controlled dimensions and pore sizes, which is required for filtration applications. The cylindrical substrates provide optimal flow dynamics for filtration applications, particularly in cross-flow (tangential) filtration, where fluids pass along the surface of the cylindrical membrane, reducing fouling and enhancing the overall efficiency of the filtration process. After forming the substantially cylindrical shape, the ceramic substrate is sintered at high temperatures (usually between 1200°C and 1600°C), which densifies the material, increases the strength and reduces the porosity of the ceramic substrate.

[0081] At step 304, the method 300 comprises coating the substantially cylindrical substrate 102 with the graphene-based compound 104. The graphene oxide and reduced graphene oxide are the most commonly used graphene-based compounds for coatings. These materials are derived from graphene and possess unique properties, such as high surface area, excellent electrical conductivity, thermal stability, and chemical resistance. The use of graphene -based compound 104 as a coating material enhances mechanical strength, chemical stability, and anti -fouling properties of the ceramic substrate, making the filtration membrane 100 highly desirable for filtration and separation technologies. In an implementation, graphene oxide in fluid form is coated over the ceramic substrate using a fine spray gun to obtain a thin, uniform, and functional graphene coating on the ceramic substrate. The coating of the graphene-based compound 104 over the ceramic substrate may also be referred to as a nanomaterial coating.

[0082] At step 306, the method 300 comprises drying the coated membrane to allow strong adhesion of the graphene-based compound 104 onto the ceramic substrate. The drying process removes any residual moisture or solvent, leading to the formation of a dense, cohesive film that adheres strongly to the ceramic substrate. The coating is typically applied in a liquid solution, where the graphene oxide is suspended carrier solvents. During drying, the solvent evaporates, leaving behind a solid graphene-based film. The drying process allows the solvent to evaporate, promoting strong adhesion through chemical interactions and interfacial bonding. The techniques like, thermal drying or vacuum drying, followed by post- drying annealing, may be used to create a uniform, durable, and defect-free graphene layer that enhances the performance and longevity of the fdtration membrane 100 in filtration systems.

[0083] In an implementation, the method 300 further comprises adding an enhancing agent to the graphene-based compound 104 or laying the enhancing agent over the graphene-based compound 104 onto the membrane to enhance the adhesion of the graphene -based compound 104 to the ceramic composition. The various methods of applying the enhancing agent over the graphene-based compound 104 and its advantages has been described in detail, for example, in FIG. 1A.

[0084] In an implementation, the coated membrane is air dried for a period between 48 to 72 hours. The ceramic substrate coated with the graphene oxide (may also be referred to as the coated membrane) is dried at room temperature, preferably for 48 hours. The air drying of the coated membrane for 48 to 72 hours allows for gradual and controlled solvent evaporation, ensuring the stability and uniformity of the graphene-based coating without introducing thermal stresses. The extended drying time causes to preserve the functional properties of the graphene oxide coating while preventing defects that could compromise the adhesion and durability of the filtration membrane 100 in practical applications like filtration.

[0085] In another implementation, the coated membrane is heat dried at a temperature in the range of 40 to 60 degrees Celsius for a period between 1 to 3 hours. The ceramic substrate coated with the graphene oxide is heat dried at a temperature of, preferably 60 °C for 1-2 hours. The drying of the coated membrane at the temperature range of 40°C to 60°C for 1 to 3 hours is an effective way to ensure rapid solvent evaporation while maintaining the structural integrity of the graphene oxide coating and the ceramic substrate. If reduced graphene oxide is used for the coating, the temperature for drying could be in the range of 150 to 300 °C. This controlled drying process promotes strong adhesion, reduces the risk of thermal damage, and ensures that the graphene oxide adheres uniformly and durably to the ceramic substrate, enhancing the membrane's performance in filtration and separation processes.

[0086] In another embodiment, the curing comprises oven heating the coated membrane at a temperature between about 80 °C and 100 °C for approximately one hour. This thermal treatment is sufficient to drive off residual solvent, initiate crosslinking reactions of silane coupling agents, and strengthen the interaction between the graphene-based compound and the ceramic substrate, without adversely affecting temperature-sensitive enhancing agents such as quaternary ammonium surfactants.

[0087] In an implementation, a fluid-permeable protective coating is applied to the graphene-coated substrate. In an implementation, the protective coating of epoxy or a polymer-based compound is applied to the coated membrane. The protective coating may be an epoxy or polymer based thin fdm. The protective coating is applied to enhance the durability and functionality of the fdtration membrane 100 without obstructing its ability to fdter fluids. The protective coating is typically designed to allow fluids to pass through while providing additional protection to the underlying graphene oxide coating from mechanical damage, fouling, and chemical degradation. The protective layer also supports in maintaining the selectivity and permeability of the fdtration membrane 100 while protecting the sensitive graphene oxide coating from abrasive compounds.

[0088] The steps 302 to 306 are only illustrative, and other alternatives can also be provided where one or more steps are added, or one or more steps are provided in a different sequence without departing from the scope of the claims herein.

[0089] EXAMPLES

[0090] General Method of preparation :

[0091] The fdtration membrane 100 is formed using a substantially cylindrical substrate from a ceramic composition, coating the substrate with a graphene-based compound and drying the coated membrane to form a durable bond between the ceramic composition and the graphene-based compound.

[0092] Example 1:

[0093] The substantially cylindrical substrate is made of the ceramic composition, for example, the ceramic composition of Alumina (A12O3) and Zirconia (ZrO2). The Alumina (AI2O3) and Zirconia (ZrCh) powders are the starting materials. These powders are finely ground to ensure homogeneity and small particle size, which improves the quality of the ceramic substrate. The powders are carefully weighed and mixed to form a homogeneous mixture.

[0094] Thereafter, a binder is added to the homogeneous mixture to hold the particles together during the shaping process. The common binders include organic compounds like polyvinyl alcohol (PVA) or paraffin wax. The powder mixture, now with the binder, is moulded into the desired shape using one of several methods, such as pressing, injection moulding, extrusion, etc. After the material is shaped, the material undergoes a de-binding process to remove the organic binder. This can be done by heating the shaped material (or green body) slowly in a furnace, which evaporates or decomposes the binder, leaving behind only the compacted ceramic powder. Thereafter, sintering is required in transforming the pressed ceramic powder into a dense, solid ceramic substrate. The green body is heated in a high- temperature furnace allowing the Alumina and Zirconia particles to fuse together at the atomic level. During sintering, the ceramic material undergoes densification, where the particles bond together, reducing porosity and increasing the strength of the ceramic substrate. The zirconia particles also play a role in toughening the material by undergoing a phase transformation during cooling, which prevents crack propagation and improves the overall fracture toughness of the ceramic substrate. Once the sintering is complete, the graphene-based compound (i.e., the graphene oxide) is coated onto the cylindrical ceramic substrate. A composition of graphene oxide is spray coated to the cylindrical ceramic substrate. The coating of the graphene oxide is either air dried for a period between 48 to 72 hours or heat dried at a temperature in the range of 40 to 60 degrees °C for a period between 1 to 3 hours.

[0095] The graphene oxide enables production of new and unique membranes and filters. These solutions improve human health by enabling access to clean water, when they are employed for water filtration. The graphene can be used as an additive within other materials to enhance a variety of technical properties, such as electrical conductivity, strength, weight reduction, fire resistance, durability, flexibility, stiffness, and UV resistance.

[0096] In the present disclosure, the term "graphene oxide" encompasses pure graphene oxide or reduced graphene oxide, as well as advanced ceramic materials (ACM) graphene oxide composite, as well as any other form of graphene oxide.

[0097] Once the graphene-based compound 104 (i.e., the graphene oxide) is coated over the substantially cylindrical substrate 102 (i.e., the ceramic substrate), the filtration membrane

[0098] 100, optionally include, a thin protective film, which is laid over the graphene-based compound 104. The protective film is coated over the graphene-based compound 104 using any of dip coating, spray coating, or spin coating, and the like.

[0099] Example 2:

[0100] The substantially cylindrical substrate 102 is made of the ceramic composition, for example, the ceramic composition of Alumina (A12O3) and Titania (TiO2). The Alumina (AI2O3) and Titania (TiO2) powders are the starting materials. Thereafter, the process of forming the cylindrical ceramic substrate using the Alumina (AI2O3) and Titania (TiO2) powders is same as described in Example 1. Also, the process of coating of the graphene-based compound 104 over the cylindrical ceramic substrate is same as described earlier, in Example 1. The filtration membrane 100 comprising the substantially cylindrical substrate 102 made of the ceramic composition of Alumina (A12O3) and Titania (TiO2) with the graphene oxide coating over the ceramic substrate is obtained.

[0101] Example 3:

[0102] The substantially cylindrical substrate 102 is made of the ceramic composition, for example, the ceramic composition of Alumina (A12O3) and Titania (TiO2). The Alumina (AI2O3) and Titania (TiO2) powders are the starting materials. Thereafter, the process of forming the cylindrical ceramic substrate using the Alumina (AI2O3) and Titania (TiO2) powders is same as described in Example 1. Also, the process of coating of the graphene-based compound 104 over the cylindrical ceramic substrate is same as described earlier, in Example 1. The filtration membrane 100 comprising the substantially cylindrical substrate 102 made of the ceramic composition of Alumina (A12O3) and Titania (TiO2) with the graphene oxide coating over the ceramic substrate is obtained.

[0103] The membrane of the present invention is suitable for treatment of challenging aqueous streams at nanofiltration level. For example, the membrane may be used in dairy processing to remove urea and related low-molecular-weight organic species from permeate streams, thereby enabling recycling and reuse of process water. The membrane may also be deployed in cooling tower blowdown recovery for data centers or power facilities, where its chemical robustness and anti-fouling properties permit operation under high total dissolved solids

[0104] (TDS) and dissolved ions such as Nitrates and related compounds. Additionally, by itself or preferably when functionalized with a cationic enhancing agent such as CTAC, the membrane demonstrates efficacy in removing PFAS compounds from water, including short-chain PFAS, via combined electrostatic and hydrophobic interactions. These embodiments illustrate the adaptability of the invention across multiple industrial and environmental water treatment applications.

[0105] Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "have", "is" used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. The word "exemplary" is used herein to mean "serving as an example, instance or illustration". Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and / or to exclude the incorporation of features from other embodiments. The word "optionally" is used herein to mean "is provided in some embodiments and not provided in other embodiments". It is appreciated that certain features of the present disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the present disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable combination or as suitable in any other described embodiment of the disclosure.

Claims

CLAIMS1. A filtration membrane (100) comprising: a substantially cylindrical substrate (102) made of a ceramic composition; a graphene-based compound (104) laid over the substantially cylindrical substrate (102) such that the graphene-based compound (104) durably adheres to the ceramic composition of the substantially cylindrical substrate (102), wherein the membrane is dried to durably adhere the graphene-based compound (104) to the ceramic composition; and an enhancing agent added to the graphene-based compound (104) or laid over the graphene-based compound (104) onto the membrane to enhance the adhesion of the graphene-based compound (104) to the ceramic composition.

2. The filtration membrane (100) of claim 1, wherein the ceramic composition comprises one or more of: oxide ceramics, non-oxide ceramics, silicate ceramics, and composite ceramics.

3. The filtration membrane (100) of claim 1 or 2, wherein the ceramic composition comprises Aluminum Oxide (AI2O3) and Zirconium Dioxide (ZrO2).

4. The filtration membrane (100) of claim 1 or 2, wherein the ceramic composition comprises Aluminum Oxide (AI2O3) and Titanium Dioxide (TiO2).

5. The filtration membrane (100) of claim 1 or 2, wherein the ceramic composition comprises Silicon Carbide (SiC).

6. The filtration membrane (100) of any of preceding claims, wherein the graphenebased compound (104) is either graphene oxide or reduced graphene oxide.

7. The filtration membrane (100) of claim 6, wherein graphene oxide is spray coated over the substantially cylindrical substrate (102).

8. The filtration membrane (100) of any preceding claim, wherein pore size of the substantially cylindrical substrate (102) is in a range of 50 nm to 200 nm.

9. The filtration membrane (100) of any preceding claim, wherein the diameter of the substantially cylindrical substrate (102) is in a range of 20 mm to 60 mm.

10. The filtration membrane (100) of any preceding claim, wherein the enhancing agent is a fluid-permeable protective coating laid over the graphene-based compound (104) on the substantially cylindrical substrate (102).

11. The filtration membrane (100) of claim 10, wherein the protective coating is epoxy or a polymer-based thin layer.

12. The filtration membrane (100) of any preceding claim, wherein the enhancing agent is a cross-linking agent laid over the graphene-based compound (104) on the substantially cylindrical substrate (102).

13. The filtration membrane (100) of any preceding claim, wherein the surface pore size is in a range of 0. 1 to 2 nm.

14. A system (200) for filtration comprising: an inlet (202) for taking in a fluid to be filtered; a first outlet (204) for collecting filtered fluid; a second outlet (206) for collecting retentate fluid; and a housing (208) disposed between the inlet (202) and the first outlet (204) and the second outlet (206), wherein the housing (208) comprises a filtration membrane (100) according to any of claims 1 to 13.

15. The system (200) of claim 14, wherein operating pressure at the inlet (202) is in a range of 0.4 to 4 bar.

16. A method (300) of forming a filtration membrane (100) comprising the steps of:forming a substantially cylindrical substrate (102) from a ceramic composition; coating the substantially cylindrical substrate (102) with a graphene-based compound (104); adding or laying over an enhancing agent (104) onto the membrane to enhance the adhesion of the graphene-based compound (104) to the ceramic composition; and drying the membrane to durably adhere the graphene-based compound (104) to the ceramic composition.

17. The method (300) of claim 16, wherein the membrane is air dried for a period between 48 to 72 hours.

18. The method (300) of claim 16, wherein the membrane is heat dried at a temperature in a range of 40 to 60 degrees Celsius for a period between 1 to 3 hours.

19. The method (300) of any of claims 16 to 18, wherein a fluid-permeable protective coating is applied to the substantially cylindrical substrate (102) onto the graphene-based compound (104).

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