Gel and gel particles containing polyvinyl alcohol, polyurethane and a fixing substance

Abstract

The present invention describes polyvinyl alcohol (PVA) gels and polyurethane (PU) / PVA gels and gel particles, methods for manufacturing gels and gel particles with immobilized substances (such as microorganisms, cells, enzymes, and / or other materials), methods for using the gels and gel particles in various different applications (such as wastewater treatment), and devices for manufacturing such gels and gel particles.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 003,516, filed on April 1, 2020, which is incorporated herein by reference in its entirety. Technical field

[0003] The present invention relates to: gels and gel particles formed from polyvinyl alcohol (PVA), which gels and gel particles may optionally contain polyurethane (PU); methods for manufacturing gels and gel particles; methods for immobilizing microorganisms, cells, enzymes, and / or other material substances in gels and gel particles; and methods for using such gels and gel particles in applications. Background art

[0004] Immobilized microorganisms and enzymes have been considered as alternative technologies to replace traditional wastewater treatment suspended sludge (SS) systems (such as activated sludge systems) (Dumitriu and Chornet, 1998). Previous studies have achieved the practice of embedding microorganisms and enzymes in polymer gel particles, but there are still various drawbacks (Kuraray Co., Ltd., 2012; Aslam et al., 2018). For example: Immobilization using PVA results in a chemically fragile structure and obvious adhesion problems. Under mechanical agitation caused by water flow or aeration, PVA gels leak from the particle surface. Embedded microorganisms, if they are denitrifying bacteria (such as Pseudomonas, etc.), will cause significant decomposition of PVA. These drawbacks limit the service life of PVA gel particles (for example, only maintaining for several months for most applications).

[0005] Some improvements to PVA gel particles involve changes in the chemical structure of PVA gel particles, such as: acetalization (Kuraray Co., Ltd., 2012), etherification (Schmidt et al., 1934), or other changes (Aslam et al., 2018). Although such functional group modifications may make PVA gel particles stronger to resist microbial decomposition, these attempts still have some drawbacks, including (1) they are not cost - effective and require higher energy, (2) they may use aldehydes, especially glutaraldehyde which is toxic to microorganisms; (3) ordinary microorganisms cannot survive under certain manufacturing conditions, such as at pH < 3 and temperatures of 40°C - 80°C, (4) produce a weak physical structure resulting in easy compaction. (5) Gel particles still rely on alginate to form in calcium ion solutions. However, the structure of alginate is unstable and easily decomposes into fragments because calcium ions, which are the chelating agent centers, are easily precipitated by phosphates in natural water. Additionally, alginate itself is easily decomposed by microorganisms as a carbon source.

[0006] Some previous reports have suggested environmentally friendly improvements to traditional immobilization processes using specific PVA-boric acid methods. Hwang suggested in U.S. Provisional Patent No. 62856328 (June 3, 2019) that adding sodium chloride, calcium chloride, and magnesium sulfate at the end of the immobilization process would improve surface strength and solve the sticking problem. In fact, however, it cannot prevent a large amount of leakage of PVA gel from inside the gel particles or the ends of trailing gel particles, indicating that the main cause of the sticking problem still exists and has not been fully solved. Huang et al. described the development of ether-type anionic polyurethane (PU) gel particles in a 2014 invention patent (Taiwan Patent I425050). The content of the 2014 application did not mention PVA for those gel particles. Earlier, Huang et al. (https: / / www.slideserve.com / tiara / pu-pva) disclosed PU / PVA immobilized cell particles in 2005. There has been little discussion about PU / PVA immobilized cell particles and PU gel particles because the resulting particle physical structures were very fragile at that time and not suitable for use as filters or in other purification or processing methods.

[0007] U.S. Patent No. 5,290,693 (1994) discloses hardening PVA gel particles by adding phosphates. However, the gel particles disclosed at that time still leaked because the gel particles hardened with phosphates were not strong enough.

[0008] Therefore, we need an improved method to improve the current manufacturing methods of gels and gel particles used for immobilizing substances (e.g., microorganisms such as bacteria and new substances that have not been immobilized before). This method can be improved by using low-toxicity chemicals, more efficient and cost-effective processes, and semi-continuous or continuous rather than batch processes. The final properties of the gels and gel particles can also be improved by providing (1) improved stability, (2) improved activity of the immobilized substances, (3) less leakage, (4) improved hardness and strength, etc. Summary of the Invention

[0009] Embodiments of the present invention include improving the structure and properties of immobilized substances such as PVA and / or PU / PVA gels and gel particles (e.g., stability, hardness, strength, providing a less harsh environment, less leakage). Embodiments of the present invention also include novel and non-obvious methods (e.g., continuous, high-efficiency processes such as using an extruder) and equipment for making PVA and / or PU / PVA gels and gel particles that contain one or more encapsulated substances, such as microorganisms (e.g., bacteria, algae, fungi, protozoa, etc.), cells, enzymes, and / or other substances (e.g., other chemical substances such as non-enzymes, other living tissues, soil, sludge, mixtures of purified / partially purified or unpurified materials).

[0010] Embodiments of these gels, gel particles, methods, and equipment can include several operations carried out in series or in combination. These operations include forming a PVA slurry solution and optionally combining PU with PVA to form a PU / PVA slurry solution. The PU is selected to be an ether-type hydrophilic polyurethane and can be heated or not heated before use or in the slurry. We use the term "slurry" to describe slurries and / or solutions, which is a comprehensive term encompassing the only occurrence or several components or terms (such as slurries, powders, mixtures, solutions, precipitates, etc.) that appear in the text at different times.

[0011] Embodiments of these gels, gel particles, methods, and equipment can also include mixing one or more anions (e.g., anion-releasing compounds) with the PVA and / or PU / PVA slurry solution and then forming a PVA gel and / or a PU / PVA gel. The one or more anions used (e.g., from the added anion-releasing compounds) can preferably include sulfate, phosphate, and / or borate anions, as well as other suitable anions or anion-releasing chemical substances, which are obvious to those of ordinary skill in the art. These operations can be carried out sequentially or in various combinations.

[0012] Embodiments of these gels, gel particles, methods, and equipment can optionally include mixing the PVA and / or PU / PVA slurry solution with an etherifying compound. The etherifying compound is a compound that increases or enhances (e.g., catalyzes) the formation of ether functional groups and is preferably sulfuric acid or other acids.

[0013] Embodiments of these gels, gel particles, methods, and devices may include remixing one or more substances, such as microorganisms (e.g., bacteria, algae, fungi, protozoa, etc.), cells, enzymes, and / or other substances (e.g., other chemical substances such as non-enzymes, other biologicals, soil, sludge, mixtures of purified / partially purified or unpurified materials) with a slurry, and then mixing a boric acid solution with the slurry containing one or more substances to be immobilized and forming a gel or gel particles. These operations can be completed sequentially or combined together. For a given application, the environment of the slurry solution can be improved by avoiding potentially harsh conditions that may be imposed. Thus, for certain applications (e.g., microorganisms, cells), the pH of the slurry may preferably be greater than about pH 3, more preferably greater than about pH 5.5, and most preferably close to about pH 7. Other applications may benefit from different pH ranges.

[0014] Preferred substances to be immobilized are microorganisms, cells, enzymes, non-enzyme chemicals, sludge, or mixtures of materials.

[0015] Embodiments of these gels, gel particles, methods, and devices may further include using batch dropping devices known in the art of the present invention, and more preferably using an extrusion device such as an extruder to form gel particles or other shapes. An extrusion device is preferably used to form gel particles or other shapes, and the operation is completed as part of a semi-continuous or continuous process. The operation of forming a gel is preferably completed by coating it on a surface or a carrier (such as a plate, a disk, or a reaction element used in a process or method).

[0016] Embodiments of these gels, gel particles, methods, and devices may then include combining one or more hardeners with the gel or gel particles containing one or more immobilized substances. The one or more preferred hardeners include cationic or cation-releasing compounds, such as alkali metals, alkaline earth metals, other metal ions, and / or mixtures thereof. The alkali metal is preferably Li + , Na + , K + , and / or mixtures thereof. The alkaline earth metal is preferably Ca 2+ , Mg 2+ , and / or mixtures thereof. Alternative metal ions that can be used are preferably Al 3+ , Fe 2+ , Fe 3+ , Zn 2+ , and Cu 2+ , and / or mixtures thereof.

[0017] Embodiments of these gels, gel particles, methods, and devices may then optionally include combining one or more enhancers with a gel or gel particles containing one or more immobilized substances. Optional one or more reinforcing agents preferably comprise fibers. Preferred fibers are synthetic fibers such as polyacrylic acid fibers, polyvinyl acetate fibers, polyacrylamide fibers, and natural fibers such as fibers from algae, cellulose, pulp, cotton, linen, and other natural sources, and / or mixtures thereof. These operations described above can be done in series or in their various combinations.

[0018] Preferred embodiments of the gel particles of the present invention are gel particles composed of PVA gel and / or PU / PVA gel, containing cross-linked PVA units and cross-linked PU / PVA units; the gel particles have one or more immobilized substances such as microorganisms (such as bacteria, algae), cells, enzymes, and / or other materials; the preferred size of the gel particles is from about 2 mm to about 6 mm, more preferably from about 3 mm to about 5 mm, and most preferably about 4 mm; preferably, after one week of use in applications such as aqueous solution treatment, less than about 10% of the PVA or immobilized substances leak from the gel particles, more preferably, after one week of use in applications such as aqueous solution treatment, less than about 1% of the PVA or immobilized substances leak from the gel particles, and most preferably, after one week of use in applications such as aqueous solution treatment, the leakage of PVA or immobilized substances from the gel particles is less than about 0.1%.

[0019] In certain preferred embodiments, including those in the above paragraphs, the hardness of the gel particles is greater than or approximately equal to 0.03 kg / cm 2 , and more preferably, the hardness of the gel particles is greater than or equal to approximately 0.1 kg / cm 2 . Most preferably, the hardness of the gel particles is greater than or equal to approximately 0.5 kg / cm 2 . In some embodiments of the present invention, a hardness greater than or equal to approximately 0.03 kg / cm 2 can improve the feasibility of the procedure.

[0020] In certain preferred embodiments, the gel particles pass a pressure test, showing preferred conditions of about less than 5% to 10% leakage or loss of PVA or immobilized substances, more preferably less than about 1% leakage or loss of PVA or immobilized substances, and most preferably no measurable leakage or loss of PVA or immobilized substances. This pressure test utilizes a velocity gradient (G≥300 s -1Up to one week. Other simulation methods or stress tests related to a given application environment can also be adopted, and gel particles are taken out during a period of the application to detect the leakage or loss of PVA from the particles. In a reverse osmosis clean aqueous solution, the leakage and loss of PVA in the gel particles can be obtained by, for example, measuring the PVA content in the solution of the gel particles, observing whether there is residual glue in the solution, observing the foaming situation, or measuring the COD (chemical oxygen demand) concentration.

[0021] Applications of representative embodiments of the present invention include, by way of example, the use of PVA and / or PU / PVA gels or gel particles in the treatment, purification procedures, and processing of various matrices and aqueous solutions. These applications include incorporating or otherwise combining the gels or gel particles of the present invention, which contain immobilized substances such as microorganisms (e.g., bacteria, algae, fungi, protozoa, etc.), cells, enzymes, and / or other materials (e.g., other chemical substances such as non-enzymes, other living tissues, soil, purified / partially purified or unpurified materials) with mixtures of matrices and aqueous solutions. For example, COD (chemical oxygen demand) can be reduced, volatile organic compounds (VOCs) can be reduced, odors can be reduced, denitrification, nitrification, and / or purification of aqueous solutions can be performed, or products can be produced. Those of ordinary skill in the art understand how to perform in, for example, in-situ or reaction tanks, rotating biological contactors, biological reaction towers, other reactor carriers (e.g., containers, pipes) and processes, and / or incorporate them into pre-existing manufacturing and purification-type processes and equipment. Thus, the method can include applying gels or gel particles containing immobilized substances to a matrix, gas, or aqueous solution, treating the matrix, gas, or aqueous solution with the gels or gel particles, and recovering (e.g., regenerating, purifying, recycling, separating, filtering, removing impurities, bypassing, etc.), separating the gels or gel particles from the treated matrix or aqueous solution. These application procedures can be applied to many different types of matrix and aqueous solution treatments, including wastewater treatment, aquaculture recirculating water treatment, aquarium water treatment, chemical process waste liquid treatment or solution production, processing process solution treatment or production, production of biofuels and biodiesel, antibiotic process solution treatment or production, and / or treatment or production of other pharmaceutical process solutions. Other applications of immobilized substances, including immobilized bacteria and algae, can be used in conjunction with embodiments of the present invention known or to be known to those of ordinary skill in the art (e.g., components of devices, biosensors, bioreactors, applications for environmental mitigation and remediation (e.g., metals, gases, toxins)).

[0022] The advantages of the embodiments of the present invention are described and are obvious throughout the specification. For example, certain embodiments allow for semi - continuous and / or continuous production using an extruder, a method that has not been applied to related aqueous solutions or especially such gel particles. Compared with previous applications of gels and gel particles (such as applications related to wastewater treatment, and new applications that have not been carried out due to the serious disadvantages of the gels and gel particles used), the disclosed method for immobilizing substances with PVA - boric acid immobilization can provide more favorable solutions, higher stability, better strength, improved adhesion performance, less leakage, better physical and chemical structures, better environmental friendliness, higher economic efficiency, etc. after improvement in pretreatment and post - treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flowchart of an embodiment of the method or process of the present invention.

[0024] Figure 2A According to an embodiment of the present invention, it is a schematic block diagram of a method or process for manufacturing gel particles containing immobilized substances (such as microorganisms, enzymes).

[0025] Figure 2B According to an embodiment of the present invention, it is a schematic diagram of a conveying mechanism in a method or process for manufacturing gel particles containing immobilized substances (such as microorganisms, enzymes).

[0026] Figure 2C is Figure 2B a right - front view of, showing a porous cover combined with the cutting piece of this embodiment.

[0027] Figure 3 It shows a preferred embodiment of PVA gel particles. When the sodium chloride solution is at a lower concentration and the conductivity increases, the particle diameter decreases and the hardness increases.

[0028] Figure 4 It shows an embodiment of using the gel particles of the present invention. During the 60 - day operation process, the requirement of the factory is met to reduce the concentration of wastewater COD (chemical oxygen demand) to below 250 mg / L, and the removal efficiency is about 50%.

[0029] Figure 5 It shows the suspended system (SS) and the immobilized system (IS) of the embodiment of the present invention, and the COD concentrations of these two systems at different influent water flow rates. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention provides a production method for immobilizing substances in PVA and / or PU / PVA gels and gel particles, where the immobilized substances are such as microorganisms (e.g., bacteria, algae, fungi, protozoa, etc.), cells, enzymes, and / or other substances (e.g., other chemical substances (such as non-enzymes), mixtures of other living bodies, soil, sludge, purified / partially purified or unpurified materials), and it is applied to many different procedures, involving substrates and / or aqueous solutions, such as aquariums, aquaculture, water and wastewater treatment, and in manufacturing and production processes (e.g., biochemical, chemical, and pharmaceutical industries). In particular, it can increase the surface strength of gels and gel particles and enhance the internal structure of gels and gel particles by combining the pretreatment and post-treatment of the PVA-boric acid cell immobilization method. At the same time, the present invention can solve the serious adhesion problem of gels and gel particles. Therefore, in the preferred embodiments of gels and gel particles, even in manufacturing factories, wastewater treatment, and use in different fields, they can remain dispersed during the process, transportation between unit operations, and / or filtration.

[0031] The present invention also describes methods for improving the production throughput and / or mass production of gels and gel particles containing immobilized substances. In particular, a high-production-efficiency extruder (Prüße et al., 2002) that has not been used with aqueous solutions at room temperature in the past is now used for the production of gel particles containing immobilized substances in the present invention. This method has the advantage of continuously discharging the PVA slurry, otherwise, other techniques, such as the dropping technique using a dropping device, can only operate intermittently.

[0032] Examples of the method for producing gels and gel particles containing immobilized substances in the present invention include:

[0033] Pretreatment: Provide a PVA (powder) slurry solution, add anions or compounds that can release anions into the PVA slurry solution and / or add compounds that can form etherification on the gels and gel particles (“etherification compounds”), such as sulfuric acid or other acids. In some preferred embodiments, an ether-type hydrophilic polyurethane can also be added, with or without heating. This PVA slurry solution must be heated to form a gel, such as a high-viscosity gel, but the chemical substances added to the slurry solution mixed with the chemical substances can also be heated or not heated. Alternatively or additionally, the etherification compound can be added after the PVA chemical substance mixed slurry solution is heated, or before or after adding anions or compounds that can release anions into the PVA slurry solution.

[0034] PVA-boric acid treatment: Microorganisms, enzymes, or other substances can be added to the PVA chemical mixture slurry. Thus, embodiments of the present invention include providing a boric acid forming solution and feeding a mixed substance (e.g., a microorganism mixture or an enzyme mixture) into the forming solution to form various immobilized substances in the gel. Then a gel is formed, such as a high-viscosity gel.

[0035] Granular or other shaped forming is optional: If gel particles are required, they can be formed by using an intermittent dropping method and equipment. More preferably, since the gels provided by the embodiments of the present invention have excellent properties, gel particles or other shapes can be formed by high-throughput, semi-continuous, and continuous and highly efficient extrusion equipment. The gel can preferably be prepared by coating on the surface of a support material, such as a plate or a disk used in a process or method.

[0036] Post-treatment: A hardening agent is provided and the gel or gel particles are placed in a solution of a cationic or cation-releasing compound such as an alkali metal or alkaline earth metal salt. The gel or gel particles can be strengthened, hardened, and dispersed in the future working medium. Such a preferred method can be carried out relatively easily and at low cost without adding expensive natural polysaccharides such as sodium alginate or subjecting the immobilized substances to toxicities and other denaturing conditions such as those from acids, aldehydes, and polyvalent anions.

[0037] Embodiments of the present invention can also use etherification as an alternative. For example, using etherification-modified PVA as a matrix, with or without mixing other internal reinforcing materials to embed substances such as microorganisms or enzymes in PVA gel ether particles. PVA (about 1% to about 20% of PVA) can be modified by adding an etherification compound such as about 0.01 to about 1% w / v of sulfuric acid or another acid. Moreover, PU (e.g., about 0.1 to about 20% of PU) can be added before or after dissolving PVA at about 90 °C to about 120 °C. These embodiments of the present invention can use a significantly smaller amount of PU (less than 5%) compared to the amounts reported in previous literature. Surprisingly, such a small amount of PU can stabilize and prevent the leakage of PVA gel from the gel particles. Alternative methods of PVA etherification using sulfuric acid or other acids can also prevent the leakage of PVA gel from the gel particles.

[0038] Therefore, the present invention provides an optional etherification improvement, which can prevent the leakage of PVA gel in PVA gel particles. The mechanical strength can be further improved by adding reinforcing materials. Some reinforcing materials, such as synthetic fibers (e.g., PVAc (polyvinyl acetate), PAA (polyacrylic acid), and PAM (polyacrylamide), etc.) and / or their mixtures, as well as natural fibers (e.g., algae, cellulose, pulp, cotton, and linen, etc., and / or their mixtures) can be added individually or in any combination to further improve the mechanical strength.

[0039] The esterification improvement of the present invention can be carried out by adding anions to PVA or PU / PVA gel to increase the mechanical strength of PVA or PU / PVA gel particles containing immobilized substances. The anions include phosphate, sulfate, nitrate, and borate with a concentration between about 0.01% and about 5%.

[0040] In the pretreatment, the heating time of the PVA slurry solution is preferably about 30 to about 90 minutes (more preferably about 60 minutes). Therefore, if through this pretreatment, at the end of the gel or gel particle process, a pressure test of the gel or gel particles is carried out using coarse bubble aeration or a similar pressure test technique for about one week or longer, preferably the PVA oligomers will not leak from the gel or gel particles. The preferred pressure test method is carried out in a 1-liter clean air aeration bottle; add 100 ml of gel particles to the aeration bottle; inject reverse osmosis (RO) water into the aeration bottle until the 1-liter mark; stir the aeration bottle with air; set the air flow to 1000 ml / min (in this way, the velocity gradient G can be about 300 sec -1 ); observe the cumulative bubble height and record it daily for one week. A bubble or foam height less than 5 cm is excellent. A more excellent pressure test result is to measure the COD to determine the leakage or loss of PVA. In "Coagulation and Flocculation in Water and Wastewater Treatment", IWA Publishing, London, Seattle, Bratby J. (2006) reported useful tests and analyses of G. Reprinted from https: / / www.iwapublishing.com / news / coagulation-and-flocculation-water-and-wastewater-treatment.

[0041] In the post-treatment, the formed PVA and / or PU / PVA gel and gel particles containing immobilized substances are removed from the boric acid solution and can be further strengthened in a solution containing alkali metal salts or alkaline earth metal salts. The concentration is about 0.5 to about 25%, and the duration is between about 30 minutes and about 15 hours, preferably about 1 to about 5 hours. Those hardening metals include Li + , Na +, K + , Ca 2+ , Mg 2+ . Other metal ions can also be used, such as Al 3+ , Fe 2+ , Fe 3+ , Zn 2+ and Cu 2+ . The preferred pH of this method is about 4 to 9.

[0042] In one embodiment of the present invention, all of the above features are completed to produce a gel or gel particles. In other embodiments of the present invention, only one or more of the foregoing features are completed to produce the gel or gel particles we need. Since changes in certain processes may create other weaknesses, overall, providing this flexibility can improve the properties of the gel or gel particles to suit the given application conditions. In these embodiments, the intention of the present invention is to take the methods and steps employed as an integrated solution to achieve the maximum or best benefits with the least drawbacks in a given application.

[0043] The embodiments provided by the present invention are used for manufacturing equipment of gels and gel particles for encapsulating and immobilizing substances such as microorganisms and enzymes, including a heating and dissolving furnace, a mixing tank, a conveying mechanism, and a forming tank. The heating and dissolving furnace contains PVA (or PU / PVA) powder particles, water, and anions, and forms a PVA (or PU / PVA) gel after heating. The mixing tank is filled with a PVA (or PU / PVA) gel mixed with substances such as microorganisms or enzymes. The conveying mechanism has a pipeline, an extrusion member, a cutting member, and a porous cover. The outlet of the pipeline is open, and the inlet is connected to the mixing tank. The extrusion member is placed in the pipeline and close to the outlet. The porous cover closes the outlet and has a plurality of openings, and the cutting member is placed outside the porous cover. Connected to the outlet of the first pipeline is the forming tank, which contains boric acid solution. The PVA (or PU / PVA) slurry is made into a PVA (or PU / PVA) gel in the heating and dissolving furnace, then mixed with one or more substances (such as microorganisms or enzymes) in the mixing tank, and then conveyed through the pipeline to the particle forming tank. The PVA (or PU / PVA) gel continuously extruded from the opening of the porous cover enters the pipeline outlet, and the PVA (or PU / PVA) gel extruded from the opening is cut into multiple segments by the cutting member. Then it enters the particle forming tank filled with boric acid solution. Then, in the particle forming tank of the boric acid solution, the PVA (or PU / PVA) gel is converted into multiple gel particles encapsulating and immobilizing substances. If an extruder is not used, the dripping technique and equipment can be applied to the gel to form gel particles.

[0044] In certain preferred embodiments, for large-scale production using an extruder, the proposed modified PVA (or PU / PVA) gel is preferably pre-treated to increase its viscosity to greater than about 5000 cps (preferably about 10000 cps), which may be the minimum requirement for the normal operation of certain extruders.

[0045] The PVA or PU / PVA gels and gel particles containing immobilized substances can have a variety of uses and applications. For example: wastewater treatment, waste gas treatment, odor treatment, aquarium water treatment, aquaculture recirculating water treatment, process solution treatment, chemical process solution treatment and production, matrix purification, production in the pharmaceutical field (drugs (such as antibiotics), supplements, ingredients), production of biofuels and biodiesel, and production in the biochemical field (such as enzymes, antibodies), etc.

[0046] The PVA or PU / PVA gels and gel particles containing immobilized substances can improve the efficacy of current existing methods and procedures. There is no leakage, or reduced or minimized leakage, of PVA or PU / PVA gels and gel particles, which are improvements over existing immobilized gels and gel particles. The gels and gel particles from the present invention contain nano-pores that allow substances to enter and exit but without leakage or reduced leakage of PVA or PU / PVA. For example, in an environment with excessive algal growth in a pond, lake, reservoir, or river, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen (NH 4 + -N, NO 2 - -N, NO 3 - -N) in the water can enter the gels and gel particles and be converted by bacteria therein into nitrogen gas. Ammonia and nitrite can be converted into nitrate, which is then absorbed by aquatic plants or algae together with phosphorus, thereby de-nitrifying the water. Losing the nitrogen and phosphorus sources, the algae will gradually decrease, and the problem of algal blooms is solved. Then the water will return to a more environmentally acceptable state. Another example is in wastewater treatment. To achieve a higher treatment efficiency for the wastewater of a process or processing plant, organic compounds (COD) can be converted into CO 2 , nitrogen-containing compounds and ammonia (NH 4 + ) can be converted by two different types of bacteria (aerobic or anaerobic bacteria) in the gels and gel particles into nitrate (NO 3 - ) and then further converted into N 2 .

[0047] Figure 1Embodiments involving adding novel and non - obvious pre - treatment steps and post - treatment steps in the PVA - boric acid immobilization method to prepare the gels and gel particles of the present invention. The original method is improved by replacing the batch - operated dropping technique with a continuously - operated extruder to perform higher - volume production and / or mass - production procedures. Figure 1 There are different steps or operations that can be adopted or modified, which are completely modified according to the specifications of the desired gels and gel particles to provide improved physical and chemical structural properties and characteristics.

[0048] In the pre - treatment embodiments of the present invention, it is shown that the outer surface and / or internal structure of the gels and gel particles are features that can be improved. For example, the PVA - boric acid method can poison microorganisms and / or inactivate enzymes over time. The embodiments of the present invention, due to having a less stringent immobilization process, can expand the application of immobilization techniques that were previously impossible for different substances. It is also hypothesized that the PVA leakage caused by using this PVA - boric acid method is due to weaknesses on the outer surface of the PVA gel particles. Therefore, pre - polymerization with anions to esterify PVA oligomers to increase the strength of the internal structure is an alternative and preferred embodiment. Some chemical reactions can also be used, such as etherifying PVA with sulfuric acid at a temperature of about 120 °C, or encapsulating the leakage points at the droplet - like tips of the glue leakage when using the dropping technique or at the cut edges on both sides when using the extruder with a heated or unheated ether - type PU copolymer.

[0049] During the gel formation in the embodiments of the present invention, there are several methods to increase the viscosity of the gel (e.g., PVA gel). For an extruder that can operate in a semi - continuous or continuous mode, high viscosity allows it to successfully perform higher - volume production and / or mass - production procedures. This may be very important compared to the batch - operated dropping technique.

[0050] In the post - treatment embodiments of the present invention, cations can be added to enhance and improve the surface properties of gels and gel particles treated with phosphates, for example. These cations can help stabilize and / or improve the surface strength of gels and gel particles (e.g., PVA gel particles) by, for example, increasing encapsulation and / or increasing hardness. Once the surface properties are more stable and / or otherwise improved, the problem of surface adhesion that may occur on the surface of such gels and gel particles can be reduced or eliminated.

[0051] Now refer to the following examples, which describe the main content disclosed by the present invention. These examples are provided for illustrative purposes only, and the main content is not limited to these examples but covers all variations that are obvious due to the teachings provided herein.

[0052] Example 1

[0053] Figure 1 Describes the PVA-boric acid method that can use the dripping technique and device or the extrusion technique and device, and the PVA-boric acid method that can be combined with the pretreatment 20 and the post-treatments 40 and 50 of the embodiments of the present invention. An aqueous solution (500 g) of PVA (99% saponification, 2400 degree of polymerization) containing 10% by weight can be mixed with a substance to be immobilized such as a microorganism or an enzyme 30. Then the PVA solution is added to a saturated boric acid solution under slow stirring, and spherical PVA gel particles are formed drop by drop. The gel particles can be kept in the saturated boric acid solution for 60 minutes. Thereafter, the gel particles can be removed from the saturated boric acid solution by a sieving device, rinsed with water, and stored in a 1-liter beaker for further testing. To measure the diameter and hardness, 5 g of the gel particles can be taken out from the beaker, and the water on their surface is removed with toilet paper. In each example, the diameter and hardness of 10 gel particles are measured. The diameter of the gel particles can be measured using a digital vernier caliper. The hardness is defined as the pressure applied to cause a 50% change in the diameter of the gel particles and is measured by a stress gauge (IMADA DPX-2TR). In all these embodiments, the diameter of the gel particles is approximately between 3 and 5 mm.

[0054] Example 2

[0055] Figure 2A is an embodiment according to the present invention, for schematically showing a method of making gel particles containing an immobilized substance (such as a microorganism or an enzyme). Figure 2B is an embodiment according to the present invention, for schematically showing a conveying mechanism of a device for manufacturing gel particles containing an immobilized substance. Figure 2C is Figure 2A the right front view of Figure 2B shows the combination of the porous cover and the cutting piece on the conveying mechanism. Refer to Figures 2A to 2C This embodiment is for a manufacturing device 100 for an immobilized substance, including: a heating and dissolving tank 110, a mixing tank 111, a conveying mechanism 120, and a particle forming tank 130. The heating and dissolving tank 110 is adapted to accommodate PVA and / or PU / PVA gel and a compound capable of releasing anions. The mixing tank 111 is adapted to accommodate PVA and / or PU / PVA gel and a substance such as a microorganism, an enzyme, or other materials for immobilization.

[0056] The conveying mechanism 120 has a pipe 121, an extrusion piece 122, a cutting piece 123, and a porous cover 124. The pipe 121 has an outlet 125 and an inlet 126 connecting the heating and dissolving tank 110 and the mixing tank 111. The extrusion piece 122 is placed in the pipe 121 and can be driven to approach the outlet 125. The porous cover 124 is close to the outlet 125 and has a plurality of openings 127, while the cutting piece 123 is placed outside the porous cover 124.

[0057] In this embodiment, the pipe 121 may be L-shaped, and the conveying mechanism 120 includes a buffer chamber 128 connected to the pipe 121 and used to accommodate the extrusion member 122. The buffer chamber 128 has a power device 1281 and a plunger rod 1282 connecting the power device 1281 and the extrusion member 122. The extrusion member 122 may be a plate corresponding to the diameter of the pipe 121. When a certain volume of PVA and / or PU / PVA gel accumulates in the pipe 121, the extrusion member 122 can be driven by the power device 1281 into the pipe 121 to push the PVA and / or PU / PVA gel out of the pipe 121 into the porous cover 124. When the extrusion is completed, the extrusion member 122 can return to the buffer chamber 128. However, the present invention is not limited thereto. The pipe 121 is not limited to an L-shape, and the extrusion member 122 can also be placed in the pipe 121 in other ways.

[0058] In this embodiment, there may be multiple cutting members 123, and each cutting member 123 includes a rotating shaft 1230 and a plurality of blades 1231 connected to the rotating shaft 1230. When the rotating shaft 1230 of each cutting member 123 rotates, the blades 1231 can slide through the opening 127 of the porous cover 124 to cut the PVA and / or PU / PVA gel extruded from the opening 127 into multiple parts. The rotating shaft 1230 can be connected to a motor (not shown) and cooperate with a controller such as a microcomputer (not shown) and the extrusion member 122. However, the present invention is not limited thereto, and the cutting member 123 can also be in other forms.

[0059] In this embodiment, the particle forming groove 130 is connected to the outlet of the pipe 121. It can be seen from the foregoing that the particle forming groove 130 is suitable for injecting an aqueous boric acid solution. Multiple segments of PVA and / or PU / PVA gel can form multiple gel particles containing immobilized substances in the forming groove 130 containing the aqueous boric acid solution.

[0060] In this embodiment, the manufacturing device 100 for gel particles containing immobilized microorganisms or enzymes (or other substances) includes a particle hardening groove 140 located beside the particle forming groove 130 and connected to the particle forming groove 130. The particle hardening groove 140 is suitable for receiving the gel particles containing immobilized substances from the particle forming groove 130. The particle hardening groove 140 contains the above-mentioned hardening solution, and enables the gel particles containing immobilized substances to be dispersed and hardened with each other. In the hardening solution, before putting the gel particles with immobilized microorganisms, enzymes or other substances into the particle hardening groove 140, it is necessary to first separate them from the aqueous boric acid solution, and then use a screening device (not shown in the figure) to separate the aqueous boric acid solution from the gel particles containing immobilized microorganisms or enzymes (or other substances) and recycle it. A drainage device (not shown in the figure) can be provided in the screening device to recycle the aqueous boric acid solution into the particle forming groove 130.

[0061] In this embodiment, the apparatus 100 for immobilizing microbial gel particles further includes a culture medium tank 150 located beside the particle hardening tank 140. The culture medium tank 150 is adapted to receive gel particles containing immobilized microorganisms, enzymes or other substances, take them out from the particle hardening tank 140 and inject the culture medium. Certain immobilized substances, such as microorganisms immobilized in gel particles, can be further cultured in the culture medium tank 150. The gel particles containing immobilized microorganisms, enzymes or other substances can be stored in the culture medium tank 150 before sale.

[0062] A trial production of the embodiment of the present invention was carried out in a local mechanical development factory. We first added anions (NaH 2 PO 4 , Na 2 HPO 4 , MgSO 4 and H 2 SO 4 ) and PU to the PVA slurry solution to increase the viscosity (as shown in Table 1) to form a PU / PVA gel, and the PU / PVA gel quickly formed immobilized microbial or enzyme gel particles in the particle forming solution containing 7% boric acid and 5% phosphate. Then, the immobilized microbial or enzyme gel particles formed in the particle forming solution were put into many different particle hardening solutions, which were respectively composed of 1% sodium chloride, ammonium chloride, ammonium sulfate or sulfuric acid. After the immobilized microbial or enzyme gel particles were soaked in the particle hardening solution for a period of time (5 hours), the particles became hard and there was no sticking phenomenon of the particles.

[0063] Table 1

[0064]

[0065]

[0066] #1: Data measured two weeks after preparation; #2: When a trace amount of iron oxide is added.

[0067] The results in Table 1 show that when the viscosity of the PVA or PU / PVA gel is greater than about 1810 CPS, the extruder can work well. Some factors affecting the viscosity include the concentrations of PU and PVA, the concentration of disodium hydrogen phosphate, the storage time of the gel and the saponification degree, etc. Batches 13 - 14 may form small gel particles with a size less than 1 mm, which are too small to be lost and cannot be actually applied in some wastewater treatments. However, these small particles can be made into fibers for use in pre-coated filters to treat fish tank water. A twin-screw extruder suitable for more viscous gels can be used to make larger particles. As shown in Table 2, batch 23 successfully formed larger particles that can be directly used for wastewater treatment.

[0068] The results in Table 2 show the situation of PVA gels containing immobilized substances in different 1% concentrations of hardening solutions. After the gel particles swell in water, their cylindrical shape changes to spherical. PVA gel particles with added sulfuric acid (batch number 52) can prevent the problem of surface adhesion and make the gel particles disperse well. This example confirms that chlorides make the particle surface whiter. Sulfates will make the gel particles more translucent compared to some other hardening solutions. In some embodiments, "whiter" means that the surface of the PVA gel particles is more condensed or less water-soluble than "translucent". For this example, all hardeners showing positive improvement are qualified hardening solutions and are representative embodiments. The hardness of the gel particles of batch number 51 is 0.037 kg / cm 2 , and the size is 4.50 ± 0.383 mm.

[0069] Table 2

[0070]

[0071] Example 3

[0072] This example shows the appearance of an embodiment of PVA gel particles, where 1% sulfuric acid (3.06 g concentrated sulfuric acid, 98%) and 10% PVA (30 g) are added to reverse osmosis water to prepare a 300 ml new method PVA slurry solution as shown in Tables 3 and 4. In Table 3, NaCl is used as the hardening solution, which is disclosed in U.S. Provisional Application No. 63003516 of April 2020 and is incorporated herein by reference. It was observed there that pretreatment with sulfuric acid will make the gel particles larger, softer and more translucent than normal, indicating a weaker chemical hydrophilic physical structure. However, these disadvantages can be corrected by the embodiments of the present invention. If the hardening cation concentration is increased to more than 0.5%, a whiter color can be observed. The results in Table 4 show a similar experiment, except that ammonium chloride (NH 4 Cl) was used as the hardening solution instead of NaCl. Only a small amount of 0.1% of NH 4 Cl is needed to make the gel particles white. Both hardening solutions (NaCl or NH 4 Cl) can disperse the gel particles in water. When the average diameter is 3.32 mm ± 0.028, a hardness of 0.017 kg / cm 2 can be achieved.

[0073] Table 3

[0074]

[0075] Table 4

[0076]

[0077]

[0078] Example 4

[0079] In this example, unheated neutral ether-type PU was added to the heated or unheated PVA slurry solution, such that under an aeration pressure test with coarse bubbles, no leakage of PVA oligomers occurred in the PVA gel particles. Table 5 shows that 6.7% PVA and 18% PU can form a white and shiny surface when hardened using phosphate and NaCl, with a hardness of only 0.005 kg / cm 2 . Batch number 94 shows that even when the hardening process was cancelled, no PVA oligomers leaked under the pressure test. Table 6 shows that if PU was added to the PVA slurry and heated beforehand, the gel particles would shrink significantly in the particle-forming liquid. The gel after mixing and heating PU and PVA became opaque, like a paste, and very viscous (viscosity measured under similar pretreatment conditions as seen in batch number 11 was 5080 CPS). Its occurrence was also manifested in the production of gel particles using a peristaltic pump with the dripping technique, with a high rotation speed presented by the peristaltic pump. Table 6 also shows that the size of the PVA gel particles with heated PU changed from 2.7 mm to a larger 4 mm. Compared with the PVA gel particles with unheated PU, the examples of these gel particles made from heated PU had a dull surface and became softer. Therefore, compared with the heated PU, the examples with unheated PU provided different and more favorable results for certain applications. As shown in batch number 104 of Table 7, having 2.75% unheated PU and 12% PVA also showed good characteristics of the PVA gel particles.

[0080] Table 5

[0081]

[0082]

[0083] Table 6

[0084]

[0085] Table 7

[0086]

[0087]

[0088] *1 PU in batch numbers 101 - 103 was heated. *2 Size in sodium chloride solution, not yet swollen after immersion in water.

[0089] Example 5

[0090] In this example, PVA gel particles pretreated with NaH 2 PO 4 and formed by the PVA-boric acid method were separately transferred into aqueous NaCl solutions with concentrations of 0.5, 1, 2, 3, 4, 5, 10, 20, 25% and kept therein for 60 minutes. Then these particles were removed from the solution and rinsed with water. The diameter and hardness of each group of 10 PVA gel particles were measured. The remaining particles were put into a 1000-mL aeration bottle for aeration pressure testing. During aeration, air was aerated at 1000 mL / min for one week, after which the particles were taken out for physical property measurement. Figure 3 It is noted that in a small amount of sodium chloride, as the conductivity of the sodium chloride solution increases, the diameter of the PVA gel particles decreases and the hardness increases. However, in these examples, when the concentration of the sodium chloride solution is higher than 5%, the opposite trend occurs. The appearance of the particles is also described in Table 8. After the aeration pressure test, the particles hardened in solutions between 0.5 and 25% remained white spherical. The particles hardened in the 0.5% solution became translucent after aeration, indicating that the physical structure of these specific PVA gel particles is weak. After the aeration pressure test, the particles hardened in solutions with a concentration higher than 5% adhered together. Therefore, in this optional post-treatment, it is preferable to use sodium chloride with a concentration of 1-5% (at least 1%) to harden. Some gels containing microorganisms exuded from other gel particles.

[0091] Table 8

[0092]

[0093] * Color of particles after pressure test with coarse bubble aeration

[0094] The performance of the gel particles in this example can be improved by applying PU, an etherified compound, and / or an anionic or anion-releasing compound to prepare the gel particles.

[0095] Example 6

[0096] In this example, those subjected to NaH 2 PO 4The PVA gel particles pretreated and formed with PVA-boric acid were transferred to a hardening solution of KCl. The concentrations of this hardening solution were 0.5%, 1%, 2% and 3% respectively, and they were kept therein for 60 minutes. Table 9 shows that as the conductivity of the KCl solution increased, the diameter of the particles decreased and the hardness of the particles also increased. After the aeration pressure test, the particles hardened in the solution with a concentration of at least 1% maintained their white spherical appearance. However, in the aeration pressure test, the particles hardened in the 0.5% solution became translucent. Some microorganisms and gel leaked from these gel particles.

[0097] Table 9

[0098]

[0099] * Color of particles after pressure test with coarse bubble aeration

[0100] By applying PU, etherified compounds and / or anionic or anion-releasing compounds to the preparation of gel particles, the performance of the gel particles in this example can be improved.

[0101] Example 7

[0102] In this example, the PVA gel particles pretreated with NaH 2 PO 4 and formed by the PVA-boric acid method were transferred to an aqueous solution of CaCl 2 The concentration of this CaCl 2 was 0.25, 0.5, 1, 2, 3, 5 and 10% respectively and they were placed therein for 60 minutes. Table 10 shows that when the concentration was below 3%, the diameter of the particles decreased as the conductivity of the CaCl 2 solution increased and the hardness of the particles increased. After the aeration pressure test, the particles hardened in the solution with a concentration between 0.5% and 2% maintained their white spherical appearance. After the aeration pressure test, the particles hardened in the solutions with a concentration of 0.25%, 3% and higher became translucent. Some microorganisms leaked from these gel particles.

[0103] Table 10

[0104]

[0105]

[0106] * Color of particles after pressure test with coarse bubble aeration

[0107] By applying PU, etherified compounds and / or anionic or anion-releasing compounds to the preparation of gel particles, the performance of the gel particles in this example can be improved.

[0108] Example 8

[0109] In this embodiment, the present invention is used for the operation of a mold factory. The PVA-boric acid method is used, which includes fully mixing an aqueous solution (150 kg) containing 10% by weight of PVA with a concentrated sludge solution (3 kg) containing microorganisms (sludge concentration > 6 g / L). The PVA gel particles are transferred to an aqueous solution of MgSO with a conductivity of 155.3 mmho / cm 4 and maintained therein for 90 minutes. Then these particles are removed from the solution and rinsed with water. The hardness of the particles is 0.44 kg / cm 2 . The average diameter of the particles is 3.14 ± 0.08 mm.

[0110] This embodiment is used for the advanced treatment of wastewater in a petrochemical factory in the Hsinchu Industrial Park. 150 kg of particles are added to a 3.2 cubic meter air-lift bioreactor. The wastewater to be treated is the effluent from the factory wastewater treatment plant. The target effluent COD (chemical oxygen demand) concentration for advanced treatment must be lower than 250 mg / L to ensure that the effluent meets the effluent standard for wastewater discharge from the industrial zone management center, i.e., COD is lower than 480 mg / L. The hydraulic retention time is 20 - 24 hours. The reaction is carried out outdoors without temperature or pH control.

[0111] Figure 4 It shows that during the 60-day operation, the COD concentration in the wastewater drops to about 250 mg / L required by the factory, and the removal efficiency finally reaches 50%. The COD removal efficiency is defined as the ratio of the COD removed in the wastewater to the initial total COD amount. During the test, ten particles are taken out from the system every day to measure their hardness. After four days, the hardness of the particles drops from 0.43 kg / cm 2 to 0.23 kg / cm 2 . However, the hardness of the particles increases to 0.41 kg / cm on the eighth day 2 and then remains between 0.40 and 0.70 kg / cm 2 . After 60 days of operation, the particles maintain their spherical shape and surface strength.

[0112] Due to the dissolution of the PVA gel particles, the on-site test once failed. In the second test, MgSO 4Post-treatment. Some PVA (less than 5%) still leaches out of these gel particles, which is not obvious in the wastewater. However, we can observe the foaming situation and check for leaks under pressure testing. In the case where there is no sulfuric acid or PU step in the pretreatment, about 12 cm of foam was observed during the pressure test. On the other hand, for the gel particles pretreated with sulfuric acid or PU according to the embodiments of the present invention, the foaming is less than 1 cm under pressure testing. This shows that through the pretreatment of the embodiments of the present invention, the leakage can be minimized.

[0113] Example 9

[0114] In another pilot plant test, the PVA-boric acid method was used together with the immobilized sludge in Example 8, except that the gel particles were transferred to a 1% NaCl solution with a conductivity of 21.5 mmho / cm and kept therein for 120 minutes. The average diameter of the particles was 4.37 ± 0.22 mm. Approximately 15 kg of the particles were added to one of two 100 L bioreactors for wastewater treatment testing in a petrochemical plant. The target wastewater for IS and SS was from the outlet of the anaerobic system of the plant's wastewater treatment. The hydraulic retention time was 8 to 12 hours. The reaction was carried out outdoors for three months without temperature or pH control.

[0115] Figure 5 It shows that even when the influent flow rate is increased to 120 mL / min (retention time 13.8 h), the immobilized gel particles can effectively remove COD. The COD removal efficiency is defined as the ratio of the COD removal amount in the wastewater inlet to the total COD. Figure 5 The COD in was measured without filtering the suspended solids at the beginning. It was corrected using a 1-micron filter paper, and the COD trends from two different systems were traced. For the suspended system (SS), old activated sludge was added regularly to prevent sludge washout. On the other side containing the embodiments of the present invention, in the outlet of the fixed system (IS), the suspended solid concentration was only 1 / 5 to 1 / 6 of that in SS. All outlet suspended solids need to be treated using a plate and frame filter press with added chemicals for recovery or treatment. Therefore, the chemical and electricity expenditures for SS will greatly increase the plant cost. In addition, the production of suspended solids in IS is less, which will provide good cost-effectiveness in disposing of the suspended solids.

[0116] Figure 5Shows the difference in COD of the effluent outlet between IS and SS. The COD of IS is always higher than that of SS. Initially, it was assumed that the COD in IS was due to the exudation of microorganisms from the gel particles, which could be observed with the naked eye. However, after examining the COD data pretreated by filtration through various sizes before measurement, we found that the leakage of PVA contributed approximately 50 mg / L of COD. Although the results of this example can meet the effluent standards, we still observed that the leakage of the gel and gel particles was not ideal. In some cases, this leakage could cause the system to malfunction. For example, in a biological laboratory environment where zebrafish are used for genetic experiments, the water needs to be denitrified to keep the fish healthy. The leakage of these gel particles would be harmful to the fish. The gel and gel particles must not only not leak, but also keep the fish alive in order to purify the water.

[0117] Therefore, in this embodiment, the properties of the gel particles used for the treatment of factory and zebrafish breeding wastewater will be improved by applying the PU, etherified compound, and / or anionic or anion-releasing compound of the present invention.

[0118] Example 10

[0119] In this embodiment, unheated PU / PVA gel particles were used to culture algae, nitrifying bacteria from the activated sludge system of a local petrochemical plant, and denitrifying pure bacteria purchased from Azoo (New Taipei City, Taiwan, China). The composition of the PU / PVA gel particles was 10% PVA (36 g) and 2.3% PU (15 g with a solid content of 55%) added to a mixture of 60 mL of microbial solution (2 g / L) and 285 mL of reverse osmosis water. The results showed that the algae grew within 2 - 3 days. The cultivation of nitrifying bacteria showed a pink color at the bottom of the water tank. During the 3-day fed-batch culture process, 800 mg / L of urea was completely utilized in a 1-liter aerated bottle. Nitrogen was released during the denitrification process, and the PU / PVA gel particles floated on the water surface. During the 2-day fed-batch culture, the concentration of NO 3 was completely utilized. This proves that the improvement of the physical and chemical structure of the PU / PVA gel particles of the present invention has no previous drawbacks and allows immobilized substances such as microorganisms with mass transfer ability to be applied in the biological field.

[0120] Literature

[0121] 1. Dumitriu, S. and Chornet, E., Processes with immobilized enzymes and cells. In “Bioconversion of waste materials to industrial products.” Martin, A. M. (Ed.) New York: Springer, Pages 29 - 102, 1998.

[0122] 2. Kuraray Co., Ltd., Shaped article made of porous hydrogel, method for producing the same and use thereof. Chinese Taiwan TW201332640 A1, 2012.

[0123] 3. Aslam, M., Kalyar, M. A., Raza, Z. A., Polyvinyl Alcohol: A Review of Research Status and Use of Polyvinyl Alcohol Based Nanocomposites. Polymer Engineering and Science. 58:2119–2132, 2018.

[0124] 4. Hashimoto, S and Furukawa, K., Immobilization of activated sludge by PVA - boric acid method. Biotechnology & Bioengineering. 30(1):52 - 9, 1987.

[0125] 5. Yao, L. and Swords, G. A., Hydrogel and methods of making and using same. US Patent: 6,268,405 B1, 2001.

[0126] 6.Ariga,O.,Takagi,H.,Nishizawa,H.,Sano,Y.,Immobilization ofmicroorganisms with PVA hardened by iterative freezing and thawing.Journal ofFermentation Technology.65:651-658,1987.

[0127] 7.Shinozaki,A.and Abe,K.,Microorganism immobilized in a gel preparedfrom polyvinyl alcohol and a polysaccharide.US Patent:5,034,324,1991.

[0128] 8.Chen,K.-C.and Lin,Y.-F.,Immobilization of microorganisms or enzymesin polyvinyl alcohol beads.US Patent:5,290,693,1994.

[0129] 9.Kitano,K.,Production of microorganism-immobilized support.JapanPatent:JPS645491A,1987.

[0130] 10.Van Dinh,P.and Bach,L.T.,Immobilized bacteria by using PVA(Polyvinyl alcohol)crosslinked with Sodium sulfate.The International Journalof Engineering Science.,7(1):41-47,2014.

[0131] 11.Schmidt,A.,Balle,G.,Eisfeld,K.,Ether of polyvinyl alcohol.USPatent:1,971,662,1934.

[0132] 12. Prüβe, U., Jahnz, U., Wittlich, P., Breford, J., Vorlop, K.-D., Bead production with Jet Cutting and rotating disk / nozzle technologies. Federal Research Center for Agriculture (FAL)-Brunswick (eds.), Agricultural Research, special issue 241, pp. 1-11, 2002.

[0133] 13. Huang, S.W., New method for producing immobilized microorganisms gel beads. US provisional: 63003516, Apr. 1, 2020.

[0134] 14. Hwang, S-.C., Lin, Y.H., Ho, Ho, H-.Y., Method for producing immobilized microorganisms gel beads. US provisional: 62856328, Jun. 3, 2019.

[0135] 15. Hwang, S-.C.J., Chang, H.M., Hsu, T.H., Treatment of the waste gas containing toluene and ethyl acetate by airlift bioreactor with PU / PVA immobilization cell beads. CHU-94-TR-05, 2005.

[0136] 16. Hwang, S-.C.J., Lin, Y.H., Chen, P.A., Lee, M.C., Ho, H.Y., Wu, J.Y., Development of a novel microbial immobilization method using anionic polyurethane, Chinese Taiwan Patent: I425050, Feb. 1, 2014.

[0137] 17. Wu PF, Teng JC, Lin YH, Hwang SCJ, Increasing algal biofuel production using Nannocholorpsis oculata cultivated with anaerobically and aerobically treated swine wastewater. Bioresource Technology. 133, p. 102 - 108, 2013.

[0138] 18. Chen KC, JY Wu, DJ Liou, SCJ Hwang, Decolorization of the textile dyes by newly isolated bacterial strains. Journal of Biotechnology. 101(1), 57 - 68, 2003.

[0139] 19. Chen KC, JY Wu, CC Huang, YM Liang, SCJ Hwang, Decolorization of azo dye using PVA - immobilized microorganisms. Journal of Biotechnology. 101(3), 241 - 252, 2003.

[0140] 20. Chen KC, JY Wu, WB Yang, SCJ Hwang, Evaluation of effective diffusion coefficient and intrinsic kinetic parameters on azo dye biodegradation using PVA - immobilized cell beads. Biotechnology and Bioengineering. 83(7), 821 - 832, 2003.

[0141] 21. Wu JY, SCJ Hwang, CT Chen, KC Chen, Decolorization of azo dye in a FBR reactor using immobilized bacteria. Enzyme and Microbial Technology. 37(1), 102 - 112, 2005.

[0142] 22. Wu JY, KC Chen, CT Chen, SCJ Hwang, Hydrodynamic characteristics of immobilized cell beads in a liquid–solid fluidized-bed bioreactor. Biotechnology and Bioengineering. 83(5), 583 - 594, 2003.

[0143] 23. He SY, YH Lin, KY Hou, SCJ Hwang, Degradation of dimethyl-sulfoxide-containing wastewater using airlift bioreactor by polyvinyl-alcohol-immobilized cell beads. Bioresource Technology. 102(10), 5609 - 5616, 2011.

[0144] 24. Lin YH, SCJ Hwang, WC Shih, KC Chen, Development of a novel microorganism immobilization method using anionic polyurethane. Journal of Applied Polymer Science. 99(3), 738 - 743, 2006.

[0145] 25. Hwang SCJ, JY Wu, YH Lin, IC Wen, KY Hou, SY He, Optimal dimethylsulfoxide biodegradation using activated sludge from a chemical plant. Process Biochemistry. 42(10), 1398 - 1405, 2007.

[0146] 26. Lin YH, SCJ Hwang, JY Wu, FY Chang, KC Chen, Simultaneous removal of carbon and nitrogen from swine wastewater using an immobilized-cell reactor. Journal of Environmental Engineering. 132(3), 423-429, 2006.

[0147] 27. Hwang SCJ, YH Lin, KS Huang, JY Lyuu, CT Hou, HH Chen, SY He, Treatment of acetone waste gases using slurry-phase airlift embedded with polyacrylamide-entrapped cell beads. Journal of the Air & Waste Management Association. 59(10), 1230-1238, 2009.

[0148] 28. Lin YH, HT Lee, HY Yin, SCJ Hwang, Method for producing butyric acid, butanol and butyrate ester. US Patent 9,371,548, 2012.

[0149] 29. He SY, SCJ Hwang, YH Lin, KY Hou, Treatment of dimethyl-sulfoxide-containing optoelectronics wastewater using airlift bioreactor with PVA-immobilized cell beads. Chemical, Biological And Environmental Engineering. 156-160, 2010.

[0150] Other embodiments

[0151] Although the description of the present invention has been made with reference to teachings, examples, and preferred embodiments, those skilled in the art can readily determine its essential characteristics and make various changes and modifications to the present invention without departing from its spirit and scope, in order to apply the present invention to various uses and conditions. Those skilled in the art, using only routine experimentation, will be able to confirm or determine many equivalents of the specific embodiments of the present invention described herein. Such equivalents are included within the scope of the present invention.

[0152] All publications, patents, and applications mentioned in this specification are hereby incorporated herein by reference.

Claims

1. A method for manufacturing a gel or gel particles that do not add sodium alginate and contain one or more immobilized substances, characterized in that, it includes the following steps (a) to (e), carried out in sequence: (a) Form an ether-type PU / PVA slurry solution containing one or more anions of ether-type PU and PVA; (b) Mix one or more substances to be immobilized with the ether-type PU / PVA slurry solution; (c) Mix a boric acid solution with the mixture formed in step (b) to form an ether-type PU / PVA gel or ether-type PU / PVA gel particles containing one or more immobilized substances; (d) Combine one or more hardeners with the ether-type PU / PVA gel or ether-type PU / PVA gel particles containing one or more immobilized substances; and (e) Optionally, combine one or more strengthening agents with the ether-type PU / PVA gel or ether-type PU / PVA gel particles containing one or more immobilized substances; wherein the hardener includes alkaline earth metal ions, other metal ions or a mixture thereof; the strengthening agent includes (a) synthetic fibers selected from polyvinyl acetate, polyacrylamide or a mixture thereof, and / or (b) natural fibers selected from algae, pulp, cotton, linen or a mixture thereof; wherein the one or more anions include sulfate, phosphate or borate anions; wherein the other metal ions are selected from aluminum ions Al 3+ , ferrous ions Fe 2+ , ferric ions Fe 3+ , zinc ions Zn 2+ , copper ions Cu 2+ or mixtures thereof; wherein the substances to be immobilized are selected from microorganisms, cells, enzymes, sludge or a mixture of these materials.

2. The method according to claim 1, characterized in that, wherein forming the ether-type PU / PVA gel or ether-type PU / PVA gel particles in step (c) can be carried out by a dropping device, an extruder or coating on a surface.

3. The method according to claim 1, characterized in that, wherein the alkaline earth metal ion is selected from calcium ions Ca 2+ , magnesium ions Mg 2+ or a mixture thereof.

4. A gel or gel particles containing one or more immobilized substances made by the method according to claim 1.

5. A method for purifying a matrix, characterized in that, it includes: (a) Applying the gel or gel particles containing one or more immobilized substances according to claim 4 to the matrix; (b) Purifying the matrix with the gel or gel particles containing one or more immobilized substances; and (c) Recovering the gel or gel particles containing one or more immobilized substances from the purified matrix.

6. A method for treating an aqueous solution, characterized in that, it includes wastewater treatment or aquaculture recirculating water treatment, including: (a) Applying the gel or gel particles containing one or more immobilized substances according to claim 4 to the aqueous solution; (b) Treating the aqueous solution can be carried out by reducing the chemical oxygen demand, reducing the odor, denitrifying and nitrifying with the gel or gel particles containing one or more immobilized substances; and (c) Recovering the gel or gel particles containing one or more immobilized substances from the treated aqueous solution.

7. A gas treatment method, characterized in that, it includes: (a) Applying the gel or gel particles containing one or more immobilized substances according to claim 4 to the gas; (b) The treatment gas can reduce volatile organic compounds and reduce odor by using a gel or gel particles containing one or more immobilized substances; and (c) Recover the gel or gel particles containing one or more immobilized substances from the treated gas.

8. A method for treating odor of a substrate with odor, characterized in that, comprising: (a) Applying the gel or gel particles containing one or more immobilized substances as described in claim 4 to the substrate with odor; (b) Treating the substrate with odor can reduce the odor of the substrate with odor by using a gel or gel particles containing one or more immobilized substances; and (c) Recover the gel or gel particles containing one or more immobilized substances from the substrate with the original odor that has been treated.

9. A method for manufacturing a gel or gel particles that do not contain sodium alginate and contain one or more immobilized substances, characterized in that, comprising the following steps (a) to (e), carried out in sequence: (a) Form a PVA slurry solution containing 0.01 - 1% w / v of one or more etherified compounds at a temperature of 120 °C, and optionally contain one or more anions; (b) Mix one or more substances to be immobilized with the PVA slurry solution; (c) Mix a boric acid solution with the mixture formed in step (b) to form a PVA gel or PVA gel particles containing one or more immobilized substances; (d) Combine one or more hardeners with the PVA gel or PVA gel particles containing one or more immobilized substances; and (e) Optionally, combine one or more strengthening agents with the PVA gel or PVA gel particles containing one or more immobilized substances; wherein the hardener includes alkaline earth metal ions, other metal ions or a mixture thereof; the strengthening agent includes (a) synthetic fibers selected from polyvinyl acetate, polyacrylamide or a mixture thereof, and / or (b) natural fibers selected from algae, pulp, cotton, linen or a mixture thereof; wherein the one or more anions include sulfate, phosphate or borate anions; wherein the other metal ions are selected from aluminum ions Al 3+ , ferrous ions Fe 2+ , ferric ions Fe 3+ , zinc ions Zn 2+ , copper ions Cu 2+ or a mixture thereof; wherein the substances to be immobilized are selected from microorganisms, cells, enzymes, sludge or a mixture of these materials.

10. The method according to claim 9, characterized in that, wherein the etherified compound referred to in step (a) is sulfuric acid or another acid.

11. The method according to claim 9, characterized in that, wherein the pH of the PVA slurry solution described in step (a) is less than pH 7.

12. The method according to claim 9, characterized in that, wherein, the pH of the PVA slurry solution described in step (a) is pH 5.

5.

13. The method according to claim 9, characterized in that, wherein, the pH of the PVA slurry solution described in step (a) is higher than pH 3.

14. The method according to claim 9, characterized in that, wherein forming the PVA gel or PVA gel particles in step (c) is carried out by a dropping device, an extruder or by coating on a surface.

15. The method according to claim 9, characterized in that, wherein the alkaline earth metal ion is selected from calcium ions Ca 2+ , magnesium ions Mg 2+ or a mixture thereof.

16. A gel or gel particle containing one or more immobilized substances prepared by the method as described in claim 9.

17. A method for purifying a matrix, characterized in that, comprising: (a) applying the gel or gel particle containing one or more immobilized substances as described in claim 16 to the matrix; (b) purifying the matrix with the gel or gel particle containing one or more immobilized substances; and (c) recovering the gel or gel particle containing one or more immobilized substances from the purified matrix.

18. A method for treating an aqueous solution, characterized in that, including wastewater treatment or aquaculture recirculating water treatment, comprising: (a) applying the gel or gel particle containing one or more immobilized substances as described in claim 16 to the aqueous solution; (b) treating the aqueous solution by reducing the chemical oxygen demand, reducing the odor, denitrifying, and nitrifying with the gel or gel particle containing one or more immobilized substances; and (c) recovering the gel or gel particle containing one or more immobilized substances from the treated aqueous solution.

19. A method for treating a gas, characterized in that, comprising: (a) applying the gel or gel particle containing one or more immobilized substances as described in claim 16 to the gas; (b) treating the gas by reducing volatile organic compounds and reducing the odor with the gel or gel particle containing one or more immobilized substances; and (c) recovering the gel or gel particle containing one or more immobilized substances from the treated gas.

20. A method for treating the odor of a matrix with an odor, characterized in that, comprising: (a) applying the gel or gel particle containing one or more immobilized substances as described in claim 16 to the matrix with an odor; (b) treating the matrix with an odor by reducing the odor of the matrix with an odor with the gel or gel particle containing one or more immobilized substances; and (c) recovering the gel or gel particle containing one or more immobilized substances from the treated matrix with the original odor.

21. A gel particle used in an application field and without adding sodium alginate, characterized in that, comprising: (a) crosslinked PVA units; (b) one or more immobilized substances, wherein the immobilized substances are selected from microorganisms, cells, enzymes or other materials, (c) the gel particle has a size of 3 mm to 5 mm, (d) Hardness is greater than or equal to 0.03 kg / cm 2 , and less than or equal to 0.70 kg / cm 2 , where the hardness is the pressure applied to cause a 50% change in the diameter of the gel particles as measured by a stress gauge. (e) wherein after the gel particle is used for one week, the gel particle has less than 10% of PVA or immobilized substances leaking from the gel particle, (f) ether-type PU.

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