DESC:TECHNICAL FIELD
The present disclosure relates to membrane composition and method. More particularly, the present disclosure relates to ceramic membrane composition and method thereof.
BACKGROUND
Ceramic membranes have gained significant attention in various industries due to their exceptional properties, including high temperature stability, chemical resistance, and mechanical strength. They are widely used in applications such as filtration, separation, and purification processes.
Existing ceramic membrane compositions often suffer from limitations such as low porosity, inadequate mechanical strength, and inefficient separation performance. Therefore, there is a need for an improved ceramic membrane composition and a process for its preparation that overcomes these limitations and provides enhanced properties.
In the field of ceramic membrane development, alumina and silica are commonly used as base materials due to their desirable characteristics. Alumina offers excellent thermal stability and chemical resistance, while silica contributes to mechanical strength and stability. However, achieving an optimal ratio between alumina and silica in the ceramic mixture is crucial to obtain the desired membrane properties.
Additionally, the selection and optimization of binders play a vital role in ensuring proper adhesion between the ceramic particles and the support structure. Polyethylene glycol (PEG) -200, Polyethylene glycol (PEG) -1500, and Carboxymethyl cellulose (CMC) are commonly used binders due to their compatibility with ceramic materials and ability to form a stable suspension.
Moreover, the porosity of the ceramic membrane is a crucial factor that affects its performance. Porous membranes offer increased surface area and enhanced permeability, making them highly efficient in separation processes. Achieving a suitable range of porosity is essential to optimize the membrane's performance in various applications.
Existing ceramic membrane compositions often suffer from limitations such as low porosity, inadequate mechanical strength, and inefficient separation performance. In the prior art, several methods have been proposed for the preparation of ceramic membranes. However, these methods often lack control over particle size distribution, uniformity of coating, and sintering conditions, leading to inconsistent membrane quality.
There is a clear need for ceramic membrane s with improved properties, especially in terms of higher porosity and better mechanical integrity. This is crucial for enhancing their performance in various industrial applications, such as filtration and separation processes. Therefore, there is a need for a technology that addresses these challenges and provides a well-controlled method for preparing a composite ceramic membrane with desired porosity, mechanical strength, and separation performance.
SUMMARY
In one aspect of the present disclosure, a ceramic membrane composition is provided.
The ceramic membrane composition includes ceramic mixture ranging from 215-235 grams such that the ceramic mixture comprises alumina and silica in a ratio of 205-230:7-9 (w/w) and binder ranging from 10.8-12.8 grams; and water ranging from 250-275 grams.
In some aspects of the present disclosure, porosity associated with the ceramic membrane ranges from 20%- 60%.
In some aspects of the present disclosure, the binders are selected from a group comprising Polyethylene glycol (PEG) - 200, Polyethylene glycol (PEG) - 1500, and Carboxymethyl cellulose (CMC) or in combination thereof.
In second aspect of the present disclosure, a method for the preparation of a composite ceramic membrane is provided. The method includes particle size reduction of alumina and silica powder reducing particle size of alumina and silica powder by way of a ball mill for 12-24 hours to obtain finer alumina balls and finer silica balls respectively of radius 0.8-1 mm. The method further includes sieving the finer alumina and the finer silica to obtain uniform particle size alumina and uniform particle size silica respectively. The method further includes mixing the uniform particle size alumina and the uniform particle size silica in the ratio of 207.1-227.1:6.9-8.9 (w/w) to obtain a ceramic mixture.
The method further includes preparing (201) a binder solution by adding adding 3-5 g of Polyethylene glycol (PEG) -200, 0.5-3g of Polyethylene glycol (PEG) -1500, and 5-7g of Carboxymethyl cellulose slowly in 250-275 grams of deionized (DI) water at approximately 350-450 rpm by stirring the solution homogeneously for 2-4 hours to obtain a clear solution.The method further includes adding 215-235 grams of the ceramic mixture to 10.8-12.8 grams of the binder solution at 350-450 rpm followed by stirring for 10-14 hours at 350-450 rpm to obtain white slurry, air-drying the white slurry for 20-28 hours and then further drying it at a temperature range of 60-70 ? for 10-14 hours to obtain dried ceramic powder.
The method further includes crushing the dried ceramic powder to remove lumps, followed by grounding the dried ceramic powder in a ball mill for 12-24 hours to obtain a-alumina ceramic powder wherein the ball mill adapted to produce 0.8 mm radius balls of volume ratio 1:2, pressing the a-alumina ceramic powder at a uniform pressure of 100-300 MPa using a hydraulic press and a stainless-steel die 1-3 hours to obtain a cylindrical disk with a diameter of 45-65 mm and thickness of 3-5 mm, sintering the cylindrical disk at a temperature of 1600-1800 ? for two hours and polishing the final support to achieve a smooth uniform surface using sandpaper.
In some aspects of the present disclosure, the method for the preparation of a composite ceramic membrane may include coating surface of the ceramic support using the sol-gel method which includes the following steps: preparing a boehmite sol by mixing aluminium isopropoxide (AIP) as a precursor and 0.001 mole of a peptizing agent in DI water in which 1 mole of AIP is used in 100 moles of DI water and allowing to reflux for 20-28 hours to obtain a transparent sol.
The method further includes removing attached particles from the surface of the ceramic support by sonication, incorporating 3-7% (w/w) polyvinyl alcohol (PVA) as Drying control chemical additives (DCCA) in the boehmite sol and stirring the mixture at 80-100 ? for 2-4 hours to obtain PVA doped boehmite sol, dipping the ceramic membrane by way of vertical dipping or dip-coating method in the PVA doped boehmite sol, with a dipping rate of 5-10 mm.min-1, a drying rate of 3-7 mm/min, and a dipping time of 1-3 minutes to obtain coated ceramic membrane.
The method further includes drying the coated ceramic membrane for 20-28 hours at ambient temperature in a closed glass petri dish; and sintering the membranes at 500-600 ? with a ramping rate of 1-3 ?/min and a holding time of 1-3 hours, repeating the process two to four times to achieve the desired pore size of the coating.
In some aspects of the present disclosure, the ceramic mixture includes nitric acid as peptizing agent.
In some aspects of the present disclosure, the ceramic mixture further includes additives selected from the group consisting of pore-forming agents, stabilizers, dispersants, and plasticizers.
In some aspects of the present disclosure, the ceramic mixture further comprises one or more dopants selected from the group consisting of metal oxides, metal salts, and metal nanoparticles.
In some aspects of the present disclosure, the binder further comprises a cross-linking agent to enhance the mechanical strength of the membrane.
In some aspects of the present disclosure, the ceramic support has a thickness ranging from 1 mm to 10 mm.
In some aspects of the present disclosure, the porosity associated with the ceramic membrane ranges from 40% to 60%.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawing,
Figure 1 illustrates an exemplary embodiment of a composite ceramic membrane, in accordance with an aspect of the present disclosure;
Figure 2 illustrates a method of preparation of a composite ceramic membrane, in accordance with an aspect of the present disclosure;
Figure 3 illustrates a method of preparing a ceramic support, in accordance with an aspect of the present disclosure; and
Figure 4 illustrates a method of coating the surface of the ceramic support using the sol-gel method, in accordance with an aspect of the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, known details are not described in order to avoid obscuring the description.
References to one or an embodiment in the present disclosure can be references to the same embodiment or any embodiment; and, such references mean at least one of the embodiments.
Reference to "one embodiment", "an embodiment", “one aspect”, “some aspects”, “an aspect” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others.
The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided.A recital of one or more synonyms does not exclude the use of other synonyms.The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various embodiments given in this specification. Without intent to limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims or can be learned by the practice of the principles set forth herein.
As mentioned before, there is a need for a technology that addresses these challenges and provides a well-controlled method for preparing a composite ceramic membrane with desired porosity, mechanical strength, and separation performance.
The present disclosure, therefore: aims to overcome the limitations of existing ceramic membrane compositions and processes by providing a novel composition and a detailed process for its preparation. The composition comprises a ceramic mixture of alumina and silica in a specific ratio, along with binders selected from PEG-200, PEG-1500, and CMC. The composition exhibits a desirable porosity ranging from 20% to 80%, offering enhanced separation efficiency.
The method involves particle size reduction of alumina and silica powder, followed by the preparation of a ceramic support through a series of steps including binder solution preparation, slurry mixing, drying, crushing, pressing, and sintering. This method ensures uniform particle distribution, adequate binding, and mechanical strength of the ceramic support.
Furthermore, the method includes a sol-gel coating method for enhancing the membrane's performance. The sol-gel method involves the preparation of a boehmite sol, removal of attached particles from the support surface, incorporation of polyvinyl alcohol (PVA) as drying control chemical additives (DCCA), coating of the support using the dip-coating method, and subsequent drying and sintering steps. By following this comprehensive process, the resulting ceramic membrane exhibits improved properties such as enhanced porosity, mechanical strength, and separation performance. The membrane can be utilized in a wide range of applications, including but not limited to filtration, separation, and purification processes in industries such as water treatment, pharmaceuticals, chemicals, and food processing.
Figure 1 illustrates an exemplary embodiment of a composite ceramic membrane, in accordance with an aspect of the present disclosure.
The ceramic membrane composition may include a ceramic mixture and a binder. The ceramic mixture may range from 215-235 grams.
The ceramic mixture may include alumina and silica. The alumina and silica may be in a ratio of 205-230:7-9 (w/w). The binder may range from 10.8-12.8 grams. The water may range from 250-275 grams.
The porosity associated with the ceramic membrane ranges from 20%- 60%. The binders may be selected from a group comprising Polyethylene glycol (PEG) - 200, Polyethylene glycol (PEG) - 1500, and Carboxymethyl cellulose (CMC) or in combination thereof.
Figure 2 illustrates a method 100 of preparation of a composite ceramic membrane, in accordance with an aspect of the present disclosure. The method 100 may include the following steps:
At step 102, the method 100 may include reducing particle size of alumina and silica powder by way of a ball mill for 12-24 hours to obtain finer alumina balls and finer silica balls respectively of radius 0.8-1 mm.
At step 104, the method 100 may include sieving the finer alumina and the finer silica to obtain uniform particle size alumina and uniform particle size silica respectively.
In an exemplary scenario, particle size reduction of alumina and silica was done by using ball mill on 0.8 mm balls for 24 hr followed by sieving on # 63 for uniform particle size and were mixed in the ratio of 205-230:7-9 w/w.
At step 106, method 100 may include preparing a ceramic support.
At step 310, the method may include coating the membrane surface using the sol-gel method.
Figure 3 illustrates a method of preparation of a composite ceramic membrane that includes preparing (106) a ceramic support, in accordance with an aspect of the present disclosure.
The method of preparing (106) a ceramic support may include the following steps:
At step 201, the method may include preparing a binder solution by preparing (201) a binder solution by adding 3-5 g of Polyethylene glycol (PEG) -200, 0.5-3g of Polyethylene glycol (PEG) -1500, and 5-7g of Carboxymethyl cellulose (CMC) slowly in 250-275 grams of deionized (DI) water at approximately 350-450 rpm by stirring the solution homogeneously for 2-4 hours to obtain a clear solution.
At step 203, method 100 may include adding 215-235 grams of the ceramic mixture to 10.8-12.8 grams of the binder solution at 350-450 rpm followed by stirring for 10-14 hours at 350-450 rpm to obtain white slurry.
At step 205, the method 100 may include air-drying the white slurry for 20-28 hours and then further drying it at a temperature range of 60-70 ? for 10-14 hours.
At step 207, the method 100 may include crushing the dried ceramic powder to remove lumps, followed by grounding the dried ceramic powder in a ball mill for 12-24 hours to obtain a-alumina ceramic powder wherein the ball mill adapted to produce 0.8 mm radius balls of volume ratio 1:2;
At step 209, the method 100 may include pressing the a-alumina ceramic powder at a uniform pressure of 203-300 MPa by way of a hydraulic press and a stainless-steel die for 1-3 hours to obtain a cylindrical disk with a diameter of 45-65 mm and thickness of 3-5 mm.
At step 211, the method 100 may include sintering the cylindrical disk at a temperature of 1600-1800 ? for two hours and polishing the final support to achieve a smooth uniform surface using sandpaper to obtain the ceramic support.
Example 1:
The ceramic support was prepared in two steps, first by preparing binder solution and then the addition of ceramic mixture. The composition of the ceramic mixture is depicted in Table 1. Binder solution was prepared by adding 3.95g of Polyethylene glycol (PEG) -200, 1.95g of Polyethylene glycol (PEG) -1500, and 5.9g of Carboxymethyl cellulose (CMC) slowly in 263.2 g of deionized (DI) water at around 400 rpm at ambient temperature. The solution was stirred homogeneously for 3 hr to get a binder solution. 225 g of ceramic mixture was added to the 11.8 g of binder solution at 400 rpm. The obtained slurry was stirred for 12 hr at 400 rpm. After mixing, the white slurry was initially air-dried for 24 hr and then dried at 60-70 ? for additional 12 hrs. The dried ceramic powder was crushed over mortar and pestle to remove lumps. Then, the powder was ball-milled (powder: ball volume ratio of 1:2) using 0.8 mm balls for 24 hrs. The a-alumina ceramic powder was pressed with uniform pressure of 203 MPa on a hydraulic press using stainless steel die. The cylindrical disk with a diameter of 55 mm and thickness of 4 mm was achieved by the die. The obtained ceramic supports were sintered at 1700 ? for two hrs and polished on sandpaper to obtain a smooth uniform surface.
Table 1 depicts the composition of the composite ceramic membrane.
Raw material Quantity (g)
ceramic mixture
Alumina 217.1
Silica 7.9
Binder solution
PEG-200 3.95
PEG-1500 1.95
CMC 5.9
Water (DI water) 263.2
Table 1
Figure 4 illustrates a method 100 of preparation of a composite ceramic membrane that includes coating 310 the surface of the ceramic support using the sol-gel method, in accordance with an aspect of the present disclosure. The method of coating 310 on surface of the ceramic support using the sol-gel method may include the following steps:
At step 300, method 100 may include preparing a boehmite sol by mixing aluminium isopropoxide (AIP) as a precursor and 0.001 mole of a peptizing agent in Deionized (DI) water in which 1 mole of AIP is used in 100 moles of DI water.
At step 301, the method 100 may include allowing reflux for 20-28 hours to obtain a transparent sol.
At step 302, the method 100 may include removing attached particles from the surface of the ceramic support by sonication.
In another exemplary scenario, the ceramic support was coated using the sol-gel method, which involved preparing a boehmite sol by refluxing aluminum isopropoxide (AIP) as a precursor, DI water, and nitric acid as a peptizing agent. For sol preparation, 1 mole of AIP was used in 100 moles of water, and 0.001 mole of nitric acid was used as a peptizing agent. The solution was refluxed for 24 hours, resulting in a transparent sol. Particles attached to the surface of the alumina ceramic support were removed by sonication.
At step 304, the method 100 may include incorporating 3-7% (w/w) polyvinyl alcohol (PVA) as Drying control chemical additives (DCCA) in the boehmite sol and stirring the mixture at 80-100 ? for 2-4 hours to obtain PVA doped boehmite sol.
At step 306, the method 100 may include dipping the ceramic membrane by way of vertical dipping or dip-coating method in the PVA doped boehmite sol, with a dipping rate of 5-10 mm.min-1, a drying rate of 3-7 mm/min, and a dipping time of 1-3 minutes.
Example 2:
The ceramic membrane was dip-coated in the PVA doped boehmite sol. To control drying, 5% (w/w) polyvinyl alcohol (PVA) was incorporated as Drying Control Chemical Additives (DCCA) into the boehmite sol. The mixture was stirred at 90 ? for 3 hours. The membrane support was then coated using the vertical dipping or dip-coating method, with a dipping rate of 5 mm.min-1, a drying rate of 5 mm.min-1, and a dipping time of 2 minutes.
At step 308, the method 100 may include drying the coated ceramic membrane for 20-28 hours at ambient temperature in a closed glass petri dish.
At step 310, the method 100 may include sintering the membranes at 500-600 ? with a ramping rate of 1-3 ?/min and a holding time of 1-3 hours, repeating the process three times to achieve the desired pore size of the coating.
In another exemplary scenario, after coating, the coated membrane support was dried for 24 hours at ambient temperature in a closed glass petri dish. Subsequently, the membranes were sintered at 550 ? with a ramping rate of 2 ?/min and a holding time of 2 hours. This process was repeated three times to achieve the desired pore size of the coating, considering a ceramic support thickness of 1mm.
Experimental analysis were performed on the present disclosure synthesized composite ceramic membrane (SC) obtained by Example 1 and Example 2. The term ‘water flux’ refers to the rate at which water passes through a membrane under a certain pressure.
Table 2 depicts membrane water flux performance. Table 1 depicts Deionized (DI) water flux on unused and used membranes, as well as water flux for effluent in different stages of the treatment process (inlet to tertiary clarifier, inlet to dual media filter, and outlet to dual media filter) and provides a comparison between Present disclosure synthesized composite ceramic membrane (SC) , commercial ceramic membrane (CC), and commercial polymeric membranes' performance under different pressures and conditions. Table 2 herein, depicts water flux which is measured in L/m².h (liters per square meter per hour) at different pressures (1 to 25 bar) for different membranes.
Comparison of Flux experimental data
SC(Present Disclosure) CC SC
(Present Disclosure) CC SC (Present Disclosure) CC Commercial Polymeric membrane
pressure (bar) DI water Flux on unused membrane
(L/m2.h) DI water Flux on unused membrane
(L/m2.h) Water Flux for effluent
(L/m2.h) Water flux for effluent
(L/m2.h) DI water flux on used membrane
(L/m2.h) DI water flux on used membrane
(L/m2.h) Pressure (bar DI water flux on unused membrane
(L/m2.h) Water flux for effluent
(L/m2.h) DI water flux on used membrane
(L/m2.h)
Inlet to tertiary clarifier
1 80.19 38.65 15.56 9.90 59.08 27.60 5 53.80 15.18 39.35
2 104.94 49.92 20.68 14.57 77.69 35.83 10 73.06 19.45 55.03
3 127.87 60.94 26.29 19.52 95.25 44.90 15 90.80 30.28 69.30
4 142.47 73.04 31.02 24.75 109.55 54.14 20 205.07 36.94 86.34
25 142.42 43.61 111.89
Inlet to dual media filter
1 80.19 38.65 16.59 10.64 63.61 28.33 5 53.80 26.03 41.34
2 104.94 49.92 22.09 15.25 84.27 37.21 10 73.06 30.04 56.38
3 127.87 60.94 23.58 20.70 103.30 45.88 15 90.80 41.03 70.20
4 142.47 73.04 25.10 27.07 115.16 55.18 20 205.07 50.77 86.73
25 142.42 54.44 111.77
Outlet to dual media filter
1 80.19 38.65 34.90 12.87 65.48 29.08 5 53.80 41.04 45.30
2 104.94 49.92 47.58 18.23 86.18 38.66 10 73.06 48.27 61.61
3 127.87 60.94 71.85 21.96 106.46 47.47 15 90.80 60.59 76.93
4 142.47 73.04 87.17 26.48 211.92 57.74 20 205.07 78.80 95.41
25 142.42 88.83 304.58

Table 2
SC: synthesized composite ceramic membrane ; CC: commercial ceramic membrane
From Table 2 it is evident that the synthesized composite ceramic membrane (SC) of the present disclosure outperforms both the commercial membranes across different pressure settings.
Inlet to tertiary clarifier: Synthesized composite ceramic membrane (SC) of the present disclosure consistently exhibits higher water flux for both DI water and effluent treatment compared to CC and the Polymeric Membrane.
Inlet to dual media filter: Similar trends are observed, with Synthesized composite ceramic membrane (SC) of the present disclosure surpassing CC and the Polymeric Membrane in water flux.
Outlet to dual media filter: Synthesized composite ceramic membrane (SC) of the present disclosure maintains higher water flux compared to the other membranes.
Table 3 depicts membrane permeability performance. Table 3 provides the permeability values (in L/m².h.bar) for synthesized composite ceramic membrane s (SC) of the present disclosure, commercial ceramic membranes (CC), and commercial polymeric membranes. Permeability is measured for unused membranes and under various operating conditions.
Comparison of Permeability data
Synthesized composite ceramic membrane
(L/m2.h.bar) Commercial ceramic membrane
(L/m2.h.bar) Commercial polymeric membrane
(L/m2.h.bar)
Unused 41.451 20.449 5.9372
Inlet to tertiary clarifier 31.281 15.017 4.5894
Inlet to dual media filter 33.423 15.37 4.62
Outlet to dual media filter 34.43 15.992 5.1048
Table 3
Table 3 indicates that Synthesized composite ceramic membrane (SC) of the present disclosure exhibits higher permeability compared to CC and the Polymeric Membrane. This higher permeability suggests that the Synthesized composite ceramic membrane allows substances to pass through more efficiently.
Table 4 depicts membrane flux decline ratio (FDR) and flux recovery ratio (FRR) performance.
Comparison of FDR-FRR experimental data
SC CC SC CC Commercial Polymeric membrane
pressure (bar) FDR (%) FDR (%) FRR (%) FRR (%) Pressure (bar) FDR (%) FRR (%)
Inlet to tertiary clarifier
1 20.43 27.05 73.67 71.41 5 23.11 73.14
2 14.35 21.71 74.04 71.77 10 11.24 75.32
3 14.38 16.74 74.50 73.69 15 7.03 76.31
4 11.82 14.08 76.90 74.12 20 6.18 77.04
25 5.64 78.56
Inlet to dual media filter
1 18.65 30.60 79.33 73.30 5 13.99 76.83
2 13.60 21.55 80.30 74.55 10 11.35 77.17
3 14.23 14.04 80.78 75.28 15 9.36 77.31
4 12.77 13.73 80.83 75.54 20 7.05 77.39
25 6.59 78.48
Outlet to dual media filter
1 10.08 23.57 81.65 75.24 5 8.59 84.19
2 7.14 12.68 82.12 77.45 10 6.73 84.33
3 5.67 11.02 83.26 77.89 15 3.96 84.72
4 4.28 10.54 83.47 71.19 20 3.88 85.13
25 3.63 87.47
SC: Synthesized composite ceramic membrane ; CC: commercial ceramic membrane
Table 4
Table 4 depicts FDR and FRR data reveal the fouling and recovery behavior of the membranes under different pressures.
Inlet to tertiary clarifier: Synthesized composite ceramic membrane (SC) of the present disclosure displays lower FDR and higher FRR compared to CC, indicating better fouling resistance and recovery.
Inlet to dual media filter: Similar trends are observed, with Synthesized composite ceramic membrane (SC) of the present disclosure showing superior performance.
Outlet to dual media filter: Again, Synthesized composite ceramic membrane (SC) of the present disclosure demonstrates lower FDR and higher FRR than CC and the Polymeric Membrane, indicating better fouling resistance and recovery.
Table 5 depicts membrane fouling performance under various conditions.
Effluent sample Inlet to tertiary clarifier Inlet to dual media filter Outlet to dual media filter
Pressure (bar) CB SB IB CLB CB SB IB CLB CB SB IB CLB
Synthesized composite ceramic membrane
1 0.9589 0.9652 0.9709 0.9806 0.9970 0.9984 0.9993 0.9998 0.9872 0.9889 0.9905 0.9932
2 0.9436 0.9487 0.9534 0.9623 0.9894 0.9914 0.9931 0.9960 0.9941 0.9948 0.9954 0.9965
3 0.9910 0.9930 0.9947 0.9974 0.9980 0.9988 0.9994 0.9998 0.9920 0.9927 0.9934 0.9946
4 0.9938 0.9951 0.9962 0.9979 0.9958 0.9970 0.9979 0.9993 0.9928 0.9933 0.9938 0.9948
Commercial ceramic membrane
1 0.9929 0.9961 0.9983 0.9995 0.9961 0.9969 0.9985 0.9994 0.9623 0.9696 0.9762 0.9869
2 0.9726 0.9779 0.9826 0.9902 0.9952 0.9973 0.9986 0.9993 0.9931 0.9945 0.9957 0.9975
3 0.9651 0.9698 0.9741 0.9817 0.9883 0.9906 0.9926 0.9958 0.9847 0.9867 0.9886 0.9920
4 0.9303 0.9359 0.9413 0.9513 0.9953 0.9966 0.9977 0.9993 0.9932 0.9945 0.9956 0.9975
Commercial polymeric membrane
5 0.8820 0.8896 0.8969 0.9105 0.9585 0.9629 0.967 0.9746 0.9554 0.9579 0.9604 0.9652
10 0.8729 0.8779 0.8828 0.8922 0.9921 0.9936 0.9949 0.9971 0.9792 0.9806 0.9819 0.9845
15 0.9772 0.9764 0.9755 0.9737 0.9757 0.9778 0.9798 0.9834 0.9892 0.9898 0.9904 0.9915
20 0.9794 0.9806 0.9819 0.9842 0.9972 0.9977 0.9981 0.9988 0.9703 0.9711 0.972 0.9737
25 0.9949 0.9955 0.9960 0.9970 0.9932 0.994 0.9947 0.9961 0.963 0.964 0.9651 0.9671
Table 5
CB: Complete blocking; SB: Standard blocking;
IB: Intermediate blocking; CBL: Cake layer blocking.
From the results depicted in Table 5, it is inferred that Synthesized composite ceramic membrane (SC) of the present disclosure shows lower values than CC and the Polymeric Membrane. Lower values suggest that SC experiences less fouling, making it a more promising option for effluent treatment.
Table 6 depicts shrinkage and porosity of the Synthesized composite ceramic membrane (SC) of the present disclosure.
Temperature
(°C) Shrinkage (%) Porosity (%)
1500 14.87 54.32
1550 20.04 45.86
1600 27.52 41.54
1650 41.86 38.76
1700 53.24 32.48
1750 56.45 31.22

From the results depicted in Table 6, it is inferred that the shrinkage increases as temperature rises, suggesting that the material contracts at higher temperatures and the porosity decreases with increasing temperature, indicating that the material becomes denser at elevated temperatures.
Table 7 provides information about the flux values of different membranes at various pressure levels.
Pressure (bar) Flux (L/m2.h)
Support 1st Coating 2nd Coating 3rd
Coating
1 205.78 115.21 94.24 80.19
2 145.33 149.87 301.11 104.94
3 169.89 173.46 142.42 127.87
4 186.64 191.74 154.63 142.47

From Table 7, it is inferred that flux generally decreases with each additional coating, indicating decreased permeability with more layers. Higher pressure levels lead to increased flux for all membranes, indicating that higher pressure enhances liquid flow.
Table 8 depicts zeta potential values at different pH levels, which represent the electrostatic charge on particle or membrane surfaces.
pH Zeta potential (mV)
3 28.2
5 25
7 9.6
8 -2.5
9 -10.4
10 -18.8

In Table 8 the Zeta potential becomes more negative with increasing pH, indicating higher repulsion between particles at higher pH levels. This can enhance stability.
Table 9 presents data on the weight loss per unit area under different pH conditions.
Chemical Stability
pH Wt. loss per unit area (mg/m2)
1 45
2 40
3 38
4 25
5 10
6 5
7 5
8 12
9 20
10 35
11 45
12 55
13 220

From Table 9, it is seen that Weight loss decreases with higher pH levels, indicating greater material stability in mildly acidic to neutral conditions. Weight loss increases significantly at pH levels 11, 12, and 13, suggesting reduced stability and severe degradation under highly alkaline conditions.In one aspect of the present disclosure, a ceramic membrane composition is provided.
The ceramic membrane composition includes ceramic mixture ranging from 215-235 grams such that the ceramic mixture comprises alumina and silica in a ratio of 205-230:7-9 (w/w) and binder ranging from 10.8-12.8 grams; and water ranging from 250-275 grams.
In some aspects of the present disclosure, the porosity associated with the ceramic membrane ranges from 20%- 60%.
In some aspects of the present disclosure, the binders are selected from a group comprising Polyethylene glycol (PEG) - 200, Polyethylene glycol (PEG) - 1500, and Carboxymethyl cellulose (CMC) or in combination thereof.
In second aspect of the present disclosure, a method for the preparation of a composite ceramic membrane is provided.
The method includes particle size reduction of alumina and silica powder reducing particle size of alumina and silica powder by way of a ball mill for 12-24 hours to obtain finer alumina balls and finer silica balls respectively of radius 0.8-1 mm. The method further includes sieving the finer alumina and the finer silica to obtain uniform particle size alumina and uniform particle size silica respectively. The method further includes mixing the uniform particle size alumina and the uniform particle size silica in the ratio of 205-230:7-9 (w/w) to obtain ceramic mixture.
The method further includes preparing (201) a binder solution by adding Polyethylene glycol (PEG)-200, Polyethylene glycol (PEG)-1500, and Carboxymethyl cellulose (CMC) slowly in 250-275 grams of deionized (DI) water at approximately 350-450 rpm by stirring the solution homogeneously for 2-4 hours to obtain a clear solution.
The method further includes adding (203) 215-235 grams of the ceramic mixture to 10.8-12.8 grams of the binder solution at 350-450 rpm followed by stirring for 10-14 hours at 350-450 rpm to obtain white slurry, air-drying the white slurry for 20-28 hours and then further drying it at a temperature range of 60-70 ? for 10-14 hours to obtain dried ceramic powder.
The method further includes crushing the dried ceramic powder to remove lumps, followed by grounding the dried ceramic powder in a ball mill for 12-24 hours to obtain a-alumina ceramic powder in a ball mill adapted to produce 0.8 mm radius balls of volume ratio 1:2, pressing the a-alumina ceramic powder at a uniform pressure of 100-300 MPa using a hydraulic press and a stainless-steel die 1-3 hours to obtain a cylindrical disk with a diameter of 45-65 mm and thickness of 3-5 mm and sintering the cylindrical disk at a temperature of 1600-1800 ? for two hours and polishing the final support to achieve a smooth uniform surface using sandpaper.
In some aspects of the present disclosure, the method 100 for the preparation of a composite ceramic membrane may include coating 310 surface of the ceramic support using the sol-gel method which includes the following steps: preparing (300) a boehmite sol by mixing aluminium isopropoxide (AIP) as a precursor and 0.001 mole of a peptizing agent in DI water in which 1 mole of AIP is used in 100 moles of DI water and allowing 301 to reflux for 20-28 hours to obtain a transparent sol.
The method 100 further includes removing (302) attached particles from the surface of the ceramic support by sonication, incorporating (304) 3-7% (w/w) polyvinyl alcohol (PVA) as Drying control chemical additives (DCCA) in the boehmite sol and stirring the mixture at 80-100 ? for 2-4 hours to obtain PVA doped boehmite sol, coating (306) the ceramic membrane by vertical dipping or dip-coating method in the PVA doped boehmite sol with a dipping rate of 5-10 mm.min-1, a drying rate of 3-7 mm/min, and a dipping time of 1-3 minutes to obtain coated ceramic membrane.
The method 100 further includes drying (308) the coated ceramic membrane for 20-28 hours at ambient temperature in a closed glass petri dish; and sintering (310) the membranes at 500-600 ? with a ramping rate of 1-3 ?/min and a holding time of 1-3 hours, repeating the process two to four times to achieve the desired pore size of the coating.
In some aspects of the present disclosure, the ceramic mixture includes nitric acid as peptizing agent.
In some aspects of the present disclosure, the ceramic mixture further includes additives selected from the group consisting of pore-forming agents, stabilizers, dispersants, and plasticizers.
In some aspects of the present disclosure, the ceramic mixture further comprises one or more dopants selected from the group consisting of metal oxides, metal salts, and metal nanoparticles.
In some aspects of the present disclosure, the binder further comprises a cross-linking agent to enhance the mechanical strength of the membrane.
In some aspects of the present disclosure, the ceramic support has a thickness ranging from 1 mm to 10 mm.
In some aspects of the present disclosure, the porosity associated with the ceramic membrane ranges from 40% to 60%.
The implementation set forth in the foregoing description does not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. Further features and/or variations can be provided in addition to those set forth herein. For example, the implementation described can be directed to various combinations and sub combinations of the disclosed features and/or combinations and sub combinations of the several further features disclosed above. In addition, the logic flows depicted in the accompany figures and/or described herein do not necessarily require the order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims.
,CLAIMS:1. A ceramic membrane composition comprising:
ceramic mixture ranging from 215-235 grams such that the ceramic mixture comprises alumina and silica in a ratio of about 205-230:7-9 (w/w);
binder ranging from 10.8-12.8 grams; and
water ranging from 250-275 grams.

2. The ceramic membrane composition as claimed in claim 1, wherein porosity associated with the ceramic membrane ranges from 20%- 60%.

3. The ceramic membrane composition as claimed in claim 1, wherein the binders are selected from a group comprising Polyethylene glycol (PEG) - 200, Polyethylene glycol (PEG) - 1500, and Carboxymethyl cellulose (CMC) or in combination thereof.

4. A method (100) for the preparation of a composite ceramic membrane, comprising:
reducing (102) particle size of alumina and silica powder by way of a ball mill for 12-24 hours to obtain finer alumina balls and finer silica balls respectively of radius 0.8-1 mm;
sieving (104) the finer alumina and the finer silica to obtain uniform particle size alumina and uniform particle size silica respectively;
mixing (105) the uniform particle size alumina and the uniform particle size silica in the ratio of 207.1-227.1:6.9-8.9 (w/w) to obtain a ceramic mixture;
preparing (106) a ceramic support; and
coating (108) surface of the ceramic support using the sol-gel method to obtain composite ceramic membrane.

5. The method for the preparation of a composite ceramic membrane as claimed in claim 4, wherein preparing (106) a ceramic support comprises the steps:
preparing (201) a binder solution by adding 3-5g of Polyethylene glycol (PEG) -200, 0.5-3g of Polyethylene glycol (PEG) -1500, and 5-7g of Carboxymethyl cellulose (CMC) slowly in 250-275 grams of deionized (DI) water at approximately 350-450 rpm by stirring the solution homogeneously for 2-4 hours to obtain a clear solution;
adding (203) 215-235 grams of the ceramic mixture to 10.8-12.8 grams of the binder solution at 350-450 rpm followed by stirring for 10-14 hours at 350-450 rpm to obtain white slurry;
air-drying (205) the white slurry for 20-28 hours and then further drying it at a temperature range of 60-70 ? for 10-14 hours to obtain dried ceramic powder;
crushing (207) the dried ceramic powder to remove lumps, followed by grounding the dried ceramic powder in a ball mill for 12-24 hours to obtain a-alumina ceramic powder wherein the ball mill adapted to produce 0.8 mm radius balls of volume ratio 1:2;
pressing (209) the a-alumina ceramic powder at a uniform pressure of 203-300 MPa by way of a hydraulic press and a stainless-steel die for 1-3 hours to obtain a cylindrical disk with a diameter of 45-65 mm and thickness of 3-5 mm; and
sintering (211) the cylindrical disk at a temperature of 1600-1800 ? for two hours and polishing the final support to achieve a smooth uniform surface using sandpaper to obtain ceramic support.

6. The method for the preparation of a composite ceramic membrane as claimed in claim 4, wherein coating (108) surface of the ceramic support using the sol-gel method, comprises the steps:
preparing (300) a boehmite sol by mixing aluminium isopropoxide (AIP) as a precursor and 0.001 mole of a peptizing agent in Deionized (DI) water wherein 1 mole of AIP is used in 100 moles of DI water and allowing (301) to reflux for 20-28 hours to obtain a transparent sol;
removing (302) attached particles from the surface of the ceramic support by sonication;
incorporating (304) 3-7% (w/w) polyvinyl alcohol (PVA) as Drying control chemical additives (DCCA) in the boehmite sol and stirring the mixture at 80-100 ? for 2-4 hours to obtain PVA doped boehmite sol;
dipping (306) the ceramic support by way of vertical dipping or dip-coating method in the PVA doped boehmite sol, with a dipping rate of 5-10 mm.min-1, a drying rate of 3-7 mm/min, and a dipping time of 1-3 minutes to obtain coated ceramic membrane;
drying (308) the coated ceramic membrane for 20-28 hours at ambient temperature in a closed glass petri dish to obtain dried membrane; and
sintering (310) the dried membranes at 500-600 ? with a ramping rate of 1-3 ?/min and a holding time of 1-3 hours, repeating the process three times to achieve the desired pore size of the coating.

7. The method for the preparation of a composite ceramic membrane as claimed in claim 4, wherein the peptizing agent is nitric acid.

8. The ceramic membrane composition as claimed in claim 4, wherein the ceramic mixture further comprises additives selected from the group consisting of pore-forming agents, stabilizers, dispersants, and plasticizers.

9. The ceramic membrane composition as claimed in claim 4, wherein the ceramic mixture further comprises one or more dopants selected from the group consisting of metal oxides, metal salts, and metal nanoparticles.

10. The ceramic membrane composition as claimed in claim 1, wherein the binder solution further comprises a cross-linking agent to enhance the mechanical strength of the membrane.

11. The ceramic membrane composition as claimed in claim 4, wherein the ceramic support has a thickness ranging from 1 mm to 10 mm.