Ceramic membrane filtration-flotation (CMFF) wastewater treatment system and treatment method thereof

Abstract

This invention relates to a ceramic membrane flotation (CMFF) wastewater treatment system and its treatment method. The method includes: a pretreatment step, in which raw water to be treated stored in a pretreatment tank is pretreated to obtain a pretreated effluent; a biological CMFF treatment step, in which organic pollutants are removed from the pretreated effluent transported to the biological CMFF treatment tank using a ceramic flat-plate membrane bioreactor (CMBR), and the effluent is filtered through the microporous structure of the CMBR. Furthermore, nano-microbubbles formed through the microporous structure carry grease and other hydrophobic pollutants contained in the pretreated effluent to the water surface to form scum and grease concentrate, which are then instantly and naturally expelled; and a CMBR backwashing step, in which the ceramic flat-plate membrane bioreactor is backwashed using compressed gas generated by the air pressure input device of the flotation backwashing unit and a control valve for regulating the delivery of the compressed gas.

Description

Technical Field

[0001] This invention relates to a ceramic membrane filtration flotation (CMFF) wastewater treatment system and its treatment method, and particularly to a wastewater treatment system and its treatment method that combines high-efficiency separation and flotation technology of ceramic membrane filtration to remove pollutants such as organic matter and grease from wastewater. Prior Technology

[0002] With industrial development, the resulting large amounts of industrial wastewater pollute rivers and soil. Industrial wastewater often contains grease, which, although relatively low in toxicity, can still negatively impact the ecological environment if discharged without proper treatment. Traditional activated sludge processes are effective for treating highly polluted wastewater, but require significant time and space. When faced with large volumes of industrial wastewater needing treatment, traditional methods still have room for improvement, and more efficient and space-saving technologies are urgently needed to address this challenge.

[0003] Existing technologies for removing oil from wastewater include physical methods, chemical methods, biological treatment methods, membrane filtration technology, and adsorption methods. Among physical methods, oil-floating separation and flocculation sedimentation are common treatment technologies. Oil-floating separation utilizes the buoyancy of oil to separate oil from water; common methods include gravity separation, flotation, and the use of oil-water separators (such as belt filters and plate and frame filters). However, oil-floating separation technology faces the following problems: First, the type of oil affects the separation effect; for emulsified or dissolved oils, flotation and gravity separation are less effective and require additional treatment. Second, during the oil-water separation process, tiny oil particles (minimum oil particle size of 0.2 micrometers) may float in the water and cannot be completely removed, resulting in low separation efficiency. Furthermore, oil-water separation equipment requires regular maintenance to prevent oil accumulation, which increases operating costs.

[0004] Furthermore, flocculation and sedimentation involves adding flocculants to wastewater, causing oil particles in the water to aggregate into larger particles, which are then removed by gravity settling or filtration. However, flocculation and sedimentation technology also presents challenges, including the need to select suitable flocculants, and the increased operating costs associated with their use. Because oil particles are small, their settling speed is slow, resulting in longer processing times; and the flocculant residue after use requires additional treatment, further increasing the difficulty and cost of treatment.

[0005] Secondly, chemical methods include chemical flocculation and neutralization. Chemical flocculation uses chemical agents such as polyvalent metal salts to promote the aggregation of oil particles, causing them to precipitate. However, the use of chemical agents produces byproducts or polluting sludge that are difficult to recycle, requiring subsequent treatment and increasing the overall complexity of the process. The purchase of chemical agents and sludge treatment are costly and require specialized operation, which not only increases operating costs but also raises management difficulties. In addition, excessive use of chemical agents may cause secondary pollution to the environment. Furthermore, neutralization is used to neutralize oils containing acidic or alkaline substances, converting them into a separable form. However, neutralization is mainly effective for acidic or alkaline oils and is less effective for other types of oils. Precise control of reaction conditions is necessary; otherwise, harmful byproducts may be generated.

[0006] Furthermore, biological treatment methods include aerobic and anaerobic biological treatment. Aerobic biological treatment decomposes organic matter, including oils, in water through the metabolism of microorganisms. Common equipment includes aeration tanks and activated sludge processes. However, aerobic treatment requires stable dissolved oxygen conditions and is sensitive to fluctuations in water quality, which may affect treatment efficiency. High oil concentrations can also coat the surface of microorganisms, affecting biochemical reactions, inhibiting microbial growth, and thus reducing treatment efficiency. In addition, biological treatment typically requires a long time to degrade oils, which may not meet the needs of immediate treatment. On the other hand, anaerobic biological treatment utilizes anaerobic microorganisms to degrade oils and is typically used to treat high-concentration oily wastewater. However, while anaerobic treatment is effective for high-concentration oils, it is less effective for wastewater containing high concentrations of ammonia nitrogen, heavy metals, or other harmful substances. Furthermore, gases produced during anaerobic treatment (such as methane) require appropriate treatment; otherwise, they may have negative environmental impacts.

[0007] Next, membrane filtration technologies include ultrafiltration (UF) and nanofiltration (NF) membranes. These membranes utilize special organic materials (such as PVDF) to filter out oil and grease from water based on physical filtration principles, achieving high separation efficiency. However, this technology also faces the following challenges: First, oily wastewater easily leads to organic membrane fouling and clogging, thereby reducing filtration efficiency, and the membrane cleaning process is complex and time-consuming. Second, membrane filtration technology has high energy requirements, especially when treating high-concentration oils, increasing operating costs. Furthermore, membrane materials are expensive and require regular replacement, further increasing maintenance and operating costs.

[0008] In addition, adsorption methods include activated carbon adsorption, which removes oily pollution by contacting oily wastewater with activated carbon and utilizing the porous structure of the activated carbon to adsorb the oil in the water. This technology is often used in combination depending on the concentration and characteristics of the oil in the wastewater and the treatment volume. In practical applications, physical, chemical, and biological treatment methods are usually combined to form a multi-stage treatment process. However, the effectiveness of adsorbents (such as activated carbon) decreases after adsorbing oil, requiring regular replacement or regeneration, thus increasing operating costs. Furthermore, the amount of oil adsorbed in a single step is limited, which may require frequent replacement of the adsorbent, further affecting treatment efficiency and increasing the operational burden.

[0009] In summary, in order to overcome the aforementioned shortcomings, the inventors of this case have devoted considerable research and development energy and spirit to continuous breakthroughs and innovations in this field, hoping to solve the deficiencies of conventional methods with novel technical means, thereby bringing better products to society and promoting industrial development. Summary of the Invention

[0010] The main objective of this invention is to provide a ceramic membrane filtration flotation (CMFF) wastewater treatment system and its treatment method. This CMFF wastewater treatment system and method are designed to address the characteristics of different types of wastewater. Combining high-efficiency separation and flotation technology with ceramic membrane filtration, it not only improves the removal efficiency of pollutants but also boasts advantages such as high treatment efficiency, strong adaptability, and low operating costs. It can be widely applied to wastewater treatment in various industries, including petrochemicals, food processing, and machinery manufacturing.

[0011] To achieve the above objectives, the present invention provides a ceramic membrane flotation (CMFF) wastewater treatment system comprising at least: a raw water storage tank, a first biological CMFF treatment tank, and a flotation backwashing unit. First, the raw water storage tank has an internal receiving space and a tank body equipped with a raw water inlet component and a raw water effluent component, for storing raw water to be treated containing at least organic matter and oil contaminants. Second, the first biological CMFF treatment tank is located downstream of the raw water storage tank and forms liquid communication with it. The first biological CMFF treatment tank has an internal first biological CMFF treatment chamber, at least one ceramic flat-plate membrane bioreactor (CMBR) disposed within the first biological CMFF treatment chamber, and a tank body equipped with a first biological treated water effluent channel. The flotation backwash unit is connected to the downstream end of the first biological CMFF treatment tank and forms a gas connection. The flotation backwash unit includes at least one high-pressure air input device (e.g., a high-pressure air CDA or an air compressor) and a control valve. The raw water to be treated includes at least one of the following: natural water bodies containing oil and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof. The ceramic flat sheet membrane bioreactor (CMBR) includes at least: a first ceramic flat sheet body having a plurality of first pores and a second ceramic flat sheet body having a plurality of second pores. The chemical oxygen demand (COD) removal rate of the raw water to be treated reaches 90% or more, and the oil removal rate of the raw water to be treated reaches 95% or more.

[0012] The CMFF wastewater treatment system of the present invention further includes a pretreatment tank, which is disposed at the downstream end of the raw water storage tank and forms a liquid connection. The pretreatment tank is used to remove large particulate solids, harmful substances or other substances that may easily damage subsequent treatment facilities from the raw water to be treated.

[0013] In the CMFF wastewater treatment system of the present invention, a first biological treatment tank is further included, which is disposed at the downstream end of the raw water storage tank and forms a liquid connection. The first biological treatment tank is a tank body having a first biological treatment chamber, a plurality of porous biological supports disposed in the biological treatment chamber, and a biologically treated water outflow channel. A gas inlet is provided at the bottom of the first biological treatment tank for gas input. The first biological treatment tank is selected from one of the following: aerobic biological treatment tank, SBR biological treatment tank, biological denitrification tank, anaerobic biological treatment tank, facultative anaerobic biological treatment tank, and combinations thereof.

[0014] The CMFF wastewater treatment system of the present invention further includes a second biological treatment tank, the second biological treatment tank having a second biological treatment chamber and a plurality of nanoporous filtration membrane devices (NFs) disposed in the second biological treatment chamber, the pore size of the nanoporous filtration membrane devices being between 0.01 and 0.001 μm.

[0015] In the CMFF wastewater treatment system of the present invention, the first biological CMFF treatment tank is configured in parallel or in series, and the at least one ceramic flat plate membrane bioreactor includes a first ceramic flat plate body having a plurality of first pores and a second ceramic flat plate body having a plurality of second pores. The pore size of the first and second pores is not particularly limited; for example, the first and second pores can have the same pore size or different pore sizes.

[0016] To achieve the aforementioned objective, the present invention provides a ceramic membrane flotation (CMFF) wastewater treatment method for treating raw water containing organic matter and oil contaminants. This treatment method includes at least the following steps: First, a pretreatment step, in which the raw water to be treated, stored in a pretreatment tank, is pretreated to remove large particulate solids, harmful substances, or other substances that could easily damage subsequent treatment facilities, resulting in a pretreated effluent.

[0017] Secondly, in the biological CMFF treatment step, the pretreated effluent transported to a biological CMFF treatment tank utilizes suspended active microorganisms and biofilms grown in a ceramic flat-plate membrane bioreactor (CMBR) in the biological CMFF treatment tank to degrade and remove organic pollutants. Suspended particles, organic residues, and colloidal substances are removed by filtration through the microporous structure of the CMBR. Furthermore, high-pressure air passes through nanobubbles formed by the microporous structure to reverse-flow the fouling on the surface of the ceramic filter membrane, and carries the oil and other hydrophobic pollutants contained in the pretreated effluent to the water surface to form a scum and an oil concentrate. The valve is then opened instantaneously, and the scum and oil concentrate are naturally expelled and removed to obtain biological CMFF treated effluent.

[0018] Furthermore, in the CMBR backwashing step, compressed gas generated by a high-pressure air input device of the flotation backwashing unit and a control valve for regulating the delivery of the compressed gas are used to backwash the ceramic flat sheet membrane bioreactor to effectively remove grease, particulate matter, organic matter, scum, and / or grease concentrates adhering to the surface of the CMBR; wherein the raw water to be treated is at least one of the following: natural water bodies containing grease and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof.

[0019] In the ceramic membrane filtration flotation (CMFF) wastewater treatment method of the present invention, the compressed gas provided by the flotation backwashing unit is air, nitrogen, carbon dioxide or a mixture thereof.

[0020] In the ceramic membrane flotation (CMFF) wastewater treatment method of the present invention, the diameter of the microbubbles ranges from 0.1 to 50 micrometers.

[0021] In the ceramic membrane flotation (CMFF) wastewater treatment method of the present invention, the chemical oxygen demand (COD) removal rate of the raw water to be treated reaches 90% or more, and the scum concentration ratio of the chemical oxygen demand is 53% or more.

[0022] In the ceramic membrane filtration flotation (CMFF) wastewater treatment method of the present invention, the oil removal rate in the raw water to be treated reaches 95% or more, and the oil scum concentration ratio is 35% or more.

[0023] The following description, with reference to the illustrations attached to this invention, details the purpose and effects of this invention, as well as the constituent components, structure, and other features of the raw water treatment system disclosed herein. Simple Explanation of the Diagram

[0024] Figure 1 is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 1 of the present invention. Figure 2 is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 2 of the present invention. Figure 3 is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 3 of the present invention. Figure 4 is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 4 of the present invention. Figure 5 is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 5 of the present invention. Figure 6 is a flowchart of the ceramic membrane flotation (CMFF) wastewater treatment method of the present invention. Figure 7 is a flowchart of another embodiment of the ceramic membrane flotation (CMFF) wastewater treatment method of the present invention. Implementation

[0025] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the invention are now described in detail with reference to the accompanying drawings. The detailed description and technical content of the present invention are illustrated below in conjunction with the accompanying drawings; however, the accompanying drawings are provided for reference and illustration only and are not intended to limit the scope of the invention.

[0026] Please refer to Figure 1, which is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 1 of the present invention.

[0027] As shown in Figure 1, the present invention provides a ceramic membrane flotation (CMFF) wastewater treatment system 1, which includes at least: a raw water storage tank 10, a first biological CMFF treatment tank 20, a flotation backwashing unit 30, and a clear water tank 40. The raw water storage tank 10 has an internal receiving space and a tank body equipped with raw water inlet components and raw water effluent components, used to store raw water to be treated containing at least organic matter and oil contaminants. The first biological CMFF treatment tank 20 is located downstream of the raw water storage tank and forms liquid communication with it. The first biological CMFF treatment tank 20 has an internal first biological CMFF treatment chamber, at least one ceramic flat-plate membrane bioreactor (CMBR) disposed in the first biological CMFF treatment chamber, and a tank body equipped with a first biological treated water effluent channel. Furthermore, the flotation backwash unit 30 is connected to the downstream end of the first biological CMFF treatment tank 20 and forms a gas connection. The flotation backwash unit includes at least an air compressor and a control valve. The raw water to be treated includes at least one of the following: natural water bodies containing oil and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof. The ceramic flat-plate membrane bioreactor (CMBR) includes at least: a first ceramic flat plate body having a plurality of first pores and a second ceramic flat plate body having a plurality of second pores. The pore size of the first and second pores is not particularly limited; for example, the first and second pores can have the same pore size or different pore sizes.

[0028] Please refer to Figure 2, which is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 2 of the present invention.

[0029] The apparatus of Embodiment 2 of the present invention is largely the same as that of Embodiment 1, except that Embodiment 2 further includes a pretreatment tank 11. As shown in FIG2, the pretreatment tank 11 is disposed at the downstream end of the raw water storage tank 10 and forms a liquid connection. The pretreatment tank 11 is used to remove large particulate solids, harmful substances or other substances that may easily damage subsequent treatment facilities from the raw water to be treated.

[0030] Please refer to Figure 3, which is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 3 of the present invention.

[0031] The apparatus of Embodiment 3 of the present invention is largely the same as that of Embodiment 2, except that Embodiment 3 further includes a first biological treatment tank 50. As shown in FIG3, the first biological treatment tank 50 is disposed at the downstream end of the pretreatment tank 11 and forms a liquid connection. The first biological treatment tank 50 is a tank body having a first biological treatment chamber, a plurality of porous biological supports disposed in the biological treatment chamber, and a biologically treated water outflow channel. A gas inlet is provided at the bottom of the first biological treatment tank 50 for gas input. The first biological treatment tank 50 is selected from one of the following: aerobic biological treatment tank, SBR biological treatment tank, biological denitrification tank, anaerobic biological treatment tank, facultative anaerobic biological treatment tank, and combinations thereof. Furthermore, the gas inlet element is at least one of the following: a porous vent pipe, a perforated vent pipe, a nozzle vent pipe, a bubble stone plate, a ventilator, and a diffuser.

[0032] Furthermore, these porous biosupport systems allow microorganisms to attach and form biofilms, thereby increasing the mean cell retention time and diversity of microorganisms. In addition, these porous biosupports are generally made of compressible polymer materials, such as open-cell PU foam. Besides having a large surface area for microorganism attachment, their compressibility allows the porous biosupports to automatically adjust their position in response to local pressure loss changes within the first biological treatment tank 50, thus avoiding blockage and uniformly dispersing gas and incoming water.

[0033] Please refer to Figure 4, which is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 4 of the present invention.

[0034] The apparatus of Embodiment 4 of the present invention is largely the same as that of Embodiment 3, except that Embodiment 4 further includes a second biological treatment tank 51. As shown in FIG4, the second biological treatment tank 51 has a second biological treatment chamber and a plurality of nanoporous filtration membrane devices (NF) disposed in the second biological treatment chamber. The pore size of the nanoporous filtration membrane devices is between 0.01 and 0.001 μm. The nanoporous filtration membrane devices are of any one of flat membrane, tubular membrane, spiral membrane, and hollow fiber membrane, preferably tubular membrane; and the nanoporous filtration membrane devices are composed of any one of cellulose acetate (CA), polyamide (PA), polysulfone (PS), peracetic acid peroxide (PAN), polypropylene (PP), thin-film composite (TFC), polyvinylidene fluoride (PVDF), and combinations thereof.

[0035] Please refer to Figure 5, which is a schematic diagram of the ceramic membrane flotation (CMFF) wastewater treatment system of Embodiment 5 of the present invention.

[0036] The apparatus of Embodiment 5 of the present invention is largely the same as that of Embodiment 3, except that Embodiment 5 further includes a second biological CMFF treatment tank 21 and two sets of flotation backwashing units 30. As shown in FIG5, the second biological CMFF treatment tank 21 is configured in parallel or in series, and the at least one ceramic plate membrane bioreactor includes a first ceramic plate body having a plurality of first pores and a second ceramic plate body having a plurality of second pores. The pore size of the first pores and the second pores is not particularly limited; for example, the first pores and the second pores can have the same pore size or different pore sizes.

[0037] Please refer to Figure 6, which is a flowchart of the ceramic membrane flotation (CMFF) wastewater treatment method of the present invention.

[0038] As shown in Figure 6, the present invention provides a ceramic membrane flotation (CMFF) wastewater treatment method, which is used to treat raw water containing organic matter and oil contaminants. The treatment method includes at least the following steps.

[0039] First, in the pretreatment step S11, the raw water to be treated stored in a pretreatment tank is pretreated to remove large particulate solids, harmful substances or other substances that may easily damage subsequent treatment facilities, and a pretreated effluent is obtained.

[0040] Secondly, in the biological CMFF treatment step S12, the pretreated effluent transported to a biological CMFF treatment tank is degraded and removed by suspended active microorganisms in the biological CMFF treatment tank and by the biofilm grown in the ceramic flat sheet membrane bioreactor (CMBR). Suspended particles, organic residues and colloidal substances are removed by filtration through the microporous structure of the CMBR. Furthermore, by using microbubbles formed through the microporous structure, the oil and other hydrophobic pollutants contained in the pretreated effluent are carried to the water surface to form a scum and an oil concentrate. The scum and the oil concentrate are further removed to obtain biological CMFF treated effluent, wherein the diameter of the microbubbles ranges from 0.1 to 50 micrometers.

[0041] Furthermore, in the CMBR backwashing step S13, the ceramic flat-sheet membrane bioreactor is backwashed using compressed gas generated by an air compressor in the flotation backwashing unit and a control valve for regulating the delivery of the compressed gas. This effectively removes grease, particulate matter, organic matter, scum, and / or grease concentrates adhering to the surface of the CMBR. The raw water to be treated is at least one of the following: natural water bodies containing grease and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof. Additionally, the compressed gas provided by the flotation backwashing unit is air, nitrogen, carbon dioxide, or a mixture thereof.

[0042] Please refer to Figure 7, which is a flowchart of another embodiment of the ceramic membrane flotation (CMFF) wastewater treatment method of the present invention.

[0043] As shown in Figure 7, in another embodiment of the present invention, a ceramic membrane flotation (CMFF) wastewater treatment method includes at least the following steps: storing raw water to be treated step S101: the raw water to be treated containing organic matter and oily pollutants is input into a raw water storage tank for storage. The raw water to be treated is at least one of the following: natural water bodies containing oil and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof.

[0044] Pretreatment step S102: The raw water to be treated is transported to a pretreatment tank to remove large particulate solids, harmful substances or other substances that may easily damage subsequent treatment facilities, and a pretreated effluent is obtained.

[0045] Biological CMFF treatment step S103: Separate oil and other hydrophobic pollutants. The pretreated raw water to be treated is transported to at least one ceramic flat sheet membrane bioreactor in a first biological CMFF treatment tank. The microbubbles generated by the ceramic flat sheet membrane bioreactor combine with the oil and other hydrophobic pollutants in the raw water to be treated, bringing them to the water surface to form scum and oil concentrate. The ceramic flat sheet membrane bioreactor filters through its microporous structure to remove fine suspended particles, organic residues and colloidal substances from the water. The diameter of the microbubbles ranges from 0.1 to 50 micrometers.

[0046] Furthermore, the ceramic flat-sheet membrane bioreactor has at least one hydrophilic coating and at least one fouling-resistant coating on its surface. The at least one hydrophilic coating is at least one of titanium dioxide nano-coating, silicon oxide coating, polyethylene glycol coating, polyoxyethylene coating, and combinations thereof. The hydrophilic coating enhances the hydrophilicity of the ceramic flat-sheet membrane bioreactor surface, making it easier for water molecules to wet the membrane surface, thereby reducing the adhesion of hydrophobic contaminants (such as grease and organic matter) to the surface of the ceramic flat-sheet membrane bioreactor. Secondly, the hydrophilic coating reduces the accumulation of contaminants on the surface of the ceramic flat-sheet membrane bioreactor, reducing the need for membrane cleaning and extending the operating cycle. In addition, the hydrophilic coating promotes microbial attachment and stable biofilm growth, improving the efficiency of the ceramic flat-sheet membrane in the bioreactor.

[0047] Furthermore, the at least one antifouling coating is at least one of a fluorinated polymer coating, a polytetrafluoroethylene nanocoating, a hydrophobic / hydrophilic hybrid structure coating, or a combination thereof. This antifouling coating possesses hydrophobic or anti-fouling properties, effectively inhibiting the adhesion of grease and other hydrophobic contaminants to the membrane surface. Secondly, the antifouling coating inhibits the growth of biofilms or bacteria on the membrane surface, reducing the risk of biofouling. Furthermore, the antifouling coating prevents direct corrosion of the ceramic membrane filter substrate by chemical contaminants or strong acid / alkali environments, extending the membrane's service life. In addition, the antifouling coating reduces the firm adhesion of contaminants, making it easier to restore the membrane's filtration performance during cleaning.

[0048] CMBR backwashing step S104: The ceramic flat-sheet membrane bioreactor is backwashed using compressed gas generated by an air compressor in the flotation backwashing unit and a control valve for regulating the delivery of the compressed gas. This effectively removes grease, particulate matter, organic matter, scum, and / or grease concentrates adhering to the surface of the CMBR. The raw water to be treated is at least one of the following: natural water bodies containing grease and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof. Furthermore, the compressed gas provided by the flotation backwashing unit is air, nitrogen, carbon dioxide, or a mixture thereof.

[0049] Step S105: The treated water from the biological CMFF treatment tank after being processed by the first biological CMFF treatment tank is exported and transported to a clean water tank for storage or further treatment.

[0050] Please refer to Table 1 below. As shown in Table 1, through this ceramic membrane flotation (CMFF) wastewater treatment method, the chemical oxygen demand (COD) removal rate in the raw water to be treated reaches 90% or more, and the COD scum concentration ratio is 53% or more. Secondly, the grease removal rate in the raw water to be treated reaches 95% or more, and the grease scum concentration ratio is 35% or more.

[0051] Table 1 Sample Name COD (mg / L) Oils and fats (mg / L) Unscreened raw water to be treated 15800 842 Scum pressed out 3020 298 Filtered water 370 10.8 Raw water to be treated after screening 5710 417 Screening raw water to be treated 4070 575 Scum pressed out 1960 167 Out of water 251 7

[0052] The chemical oxygen demand (COD) removal rate, COD removal efficiency, COD scum concentration ratio, and oil removal rate, oil removal efficiency, and oil scum concentration ratio in the raw water to be treated meet the following relationships (1), (2), (3), and (4), respectively: Equation (1): COD removal rate = (COD of raw water to be treated after screening - COD of filtered water) / COD of raw water to be treated after screening; Equation (2): COD removal efficiency = (COD of unscreened raw water to be treated - COD of screened raw water to be treated) / COD of unscreened raw water to be treated; Equation (3): COD scum concentration ratio = 1 - [(COD of raw water to be treated after screening - scum pressed out) / COD of raw water to be treated after screening]; Formula (4): Oil removal rate = (Oil in raw water after sieving - Oil in filtered water) / Oil in raw water after sieving; Equation (5): Grease removal efficiency = (Oil in unscreened raw water - Oil in screened raw water) / Oil in unscreened raw water; Formula (6): Oil scum concentration ratio = 1 - [(oil in unscreened raw water to be treated - scum pressed out) / raw water to be treated after screening].

[0053] In summary, the ceramic membrane flotation (CMFF) wastewater treatment system and method of this invention mainly achieves efficient removal of grease, organic matter, and suspended particles from wastewater through air flotation separation, ceramic membrane filtration, and compressed air backwashing protection. The air flotation technology of this invention utilizes microbubbles to combine with grease and hydrophobic pollutants in wastewater, carrying them to the water surface to form scum, achieving efficient separation. This is particularly suitable for wastewater treatment in industries such as catering and petrochemicals, significantly reducing the concentration of grease in the water. Secondly, the backwashing unit of this invention effectively removes adhering pollutants from the membrane surface of the ceramic flat-sheet membrane bioreactor through compressed gas backwashing, extending the membrane's lifespan, reducing the frequency of membrane replacement, and maintaining high removal efficiency. This invention can provide stable, high-quality effluent, adapting to various wastewater treatment needs, while also possessing the characteristics of energy saving, environmental protection, and low operating costs.

[0054] 1: Ceramic Membrane Filtration (CMFF) Wastewater Treatment System 10: Raw water storage tank 11: Pre-treatment tank 20: First biological CMFF treatment tank 21: Second biological CMFF treatment tank 30: Float Backwash Unit 40: Clear water tank 50: First biological treatment tank 51: Second biological treatment tank

Claims

1. A ceramic membrane flotation (CMFF) wastewater treatment system, comprising at least: A raw water storage tank, which has an internal receiving space and a raw water inlet component and a raw water outlet component, is used to store raw water to be treated containing at least organic matter and oil contaminants; A first biological treatment tank is arranged at the downstream end of the raw water storage tank and forms a liquid connection, the first biological treatment tank having an internal first biological treatment chamber, a plurality of porous biological supports arranged in the biological treatment chamber, and a pool body with a biologically treated water outlet channel; A first biological CMFF treatment tank is disposed downstream of the raw water storage tank and forms liquid communication. The first biological CMFF treatment tank has a first biological CMFF treatment chamber, at least one ceramic flat sheet membrane bioreactor (CMBR) disposed in the first biological CMFF treatment chamber, and a tank body with a first biological treated water effluent channel. A flotation backwash unit is connected downstream of the first biological CMFF treatment tank and forms gas communication. The flotation backwash unit includes at least one air pressure input device and a control valve, which can provide compressed gas to the at least one ceramic flat sheet membrane bioreactor (CMBR). The raw water to be treated includes at least one of the following: natural water bodies containing oil and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof. The porous biological support is made of open-cell PU foam. The ceramic flat-plate membrane bioreactor (CMBR) comprises at least: a first ceramic flat plate body having a plurality of first pores and a second ceramic flat plate body having a plurality of second pores; the surface of the ceramic flat-plate membrane bioreactor has at least one hydrophilic coating and at least one fouling-resistant coating, wherein the at least one hydrophilic coating is at least one of titanium dioxide nano-coating, silicon oxide coating, polyethylene glycol coating, polyoxyethylene coating, and combinations thereof, and the at least one fouling-resistant coating is at least one of fluorinated polymer coating, polytetrafluoroethylene nano-coating, and combinations thereof; the chemical oxygen demand (COD) removal rate of the raw water to be treated reaches 90% or above; and the oil removal rate of the raw water to be treated reaches 95% or above.

2. The ceramic membrane flotation (CMFF) wastewater treatment system described in claim 1 further includes a pretreatment tank, which is located downstream of the raw water storage tank and forms a liquid connection therewith. The pretreatment tank is used to remove large particulate solids, harmful substances, or other substances that may easily damage subsequent treatment facilities from the raw water to be treated.

3. The ceramic membrane flotation (CMFF) wastewater treatment system as described in claim 1, wherein a gas inlet is provided at the bottom of the first biological treatment tank for gas input, and the first biological treatment tank is selected from one of the following: aerobic biological treatment tank, SBR biological treatment tank, biological denitrification tank, anaerobic biological treatment tank, facultative biological treatment tank, and combinations thereof.

4. The ceramic membrane flotation (CMFF) wastewater treatment system as described in claim 1 further includes a second biological treatment tank, the second biological treatment tank having a second biological treatment chamber and a plurality of nanoporous filtration membrane devices (NFs) disposed in the second biological treatment chamber, the pore size of the nanoporous filtration membrane devices being between 0.01 and 0.001 μm.

5. The ceramic membrane flotation (CMFF) wastewater treatment system as described in claim 1, wherein the first biological CMFF treatment tank is composed of a plurality of parallel or series configurations, and the at least one ceramic plate membrane bioreactor includes a first ceramic plate body having a plurality of first pores and a second ceramic plate body having a plurality of second pores.

6. A ceramic membrane filtration flotation (CMFF) wastewater treatment method for treating raw water containing organic matter and oil contaminants, comprising at least the following steps: a pretreatment step, wherein the raw water to be treated is pretreated in a pretreatment tank to remove large particulate solids, harmful substances, or other substances that may easily damage subsequent treatment facilities, and to obtain a pretreated effluent; a biological CMFF treatment step, wherein the pretreated effluent, which is transported to a biological CMFF treatment tank, utilizes suspended active microorganisms in the biological CMFF treatment tank and a biofilm grown in a ceramic flat-plate membrane bioreactor (CMBR) to degrade and remove organic contaminants, and filters suspended particles, organic residues, and colloidal substances through the microporous structure of the CMBR, and uses microbubbles formed by high-pressure air passing through the microporous structure to reverse-flow the surface fouling of the ceramic flat-plate membrane bioreactor, so that the oil and other hydrophobic contaminants contained in the pretreated effluent are carried to the water surface to form a scum and an oil concentrate, which is then further processed. The process involves removing the scum and grease concentrate in one step to obtain a biological CMFF treated effluent; and a CMBR backwashing step, in which the ceramic flat sheet membrane bioreactor is backwashed by using compressed gas generated by an air compressor in the backwashing unit and a control valve for regulating the delivery of the compressed gas, so as to effectively remove grease, particulate matter, organic matter, scum, and / or grease concentrate adhering to the surface of the CMBR; wherein the raw water to be treated is at least one of the following: natural water bodies containing grease and organic pollution, groundwater, reservoir water, industrial water, circulating water, recycled water, secondary water, effluent, wastewater treatment plant effluent, and combinations thereof.

7. The ceramic membrane flotation (CMFF) wastewater treatment method as described in claim 6, wherein the compressed gas provided by the flotation backwash unit is air, nitrogen, carbon dioxide, or a mixture thereof.

8. The ceramic membrane flotation (CMFF) wastewater treatment method as described in claim 6, wherein the microbubble diameter ranges from 20 to 50 micrometers.

9. The ceramic membrane flotation (CMFF) wastewater treatment method as described in claim 6, wherein the chemical oxygen demand (COD) removal rate of the raw water to be treated reaches 90% or more.

10. The ceramic membrane flotation (CMFF) wastewater treatment method as described in claim 6, wherein the oil removal rate in the raw water to be treated reaches 95% or more.

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