Photocatalytic composite materials and methods for using them for water and / or sediment purification.

Abstract

This instruction describes a photocatalytic composite material useful for purifying aquatic bodies such as lakes, ponds, wetlands, and rice paddies, as well as for purifying sediments in water.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the interests and priority thereto of U.S. Patent Application No. 63 / 490,596 filed March 16, 2023, and U.S. Patent Application No. 63 / 607,212 filed December 7, 2023, the entire contents of which are incorporated herein by reference.

[0002] field This instruction relates to the purification of water and / or sediment using photocatalytic composite materials that float or are suspended in bodies of water requiring purification. [Background technology]

[0003] background The global expansion of industrial production and leisure facilities continues to broaden the scope of water quality problems. Sewage, agricultural and industrial wastewater, as well as leisure activities, aquaculture, and sewage treatment, all contribute to the global spread of damaged waters (eutrophication), and there is no cost-effective low-carbon profile strategy to restore them to a naturally sustainable state.

[0004] Numerous new and recycled technologies have been deployed globally to prevent and address the signs of eutrophication—algal blooms, most urgently cyanobacteria ("BGA") and red tides—but, predictably, have been largely unsuccessful. Attempts to reduce pollutants may have an impact, but broader environmental trends and history suggest that restraint is not the solution. Water makes up 80% of the Earth and has always played a central role in human endeavors and ingenuity. Strategies developed to reduce pollutants by absorbing or breaking down harmful substances and heavy metals in aquatic bodies, including the use of mechanical and biocatalysts, precipitating suspended solids by adding polymer electrolyte coagulants, or cultivating exogenous microorganisms with enzymatic additives, address only half the problem—water clarification and temporary algal suppression—while in reality contributing to the negative cycle on the other side of the zero-sum game of water versus sediment.

[0005] Widespread industrial use of water resources, coupled with the predictably expanding runoff of chemical fertilizers deployed to address declining soil productivity in agriculture, is overwhelming the Earth's natural carbon cycle, which relies on healthy lakes and marshes to decompose carbon emissions and expose them to sunlight for photosynthesis. This decomposition means that solutions are needed to purify the water and remove accumulated sediment. To put it bluntly, degraded waterways with high turbidity cannot purify themselves and only facilitate the constant delivery of suspended matter to the bottom, reducing the water's capacity, which is more quickly overcome by increasing the level of environmental organic sediment.

[0006] At that point, nature deploys its apex predator, the BGA, to attack and consume the suspended nutrients in degraded lakes and ponds. Eventually, only the BGA can process the available nutrients, which are converted from widely disposable carbon into nitrogen and phosphorus fixed in the sediment. While alternative methods such as filters and air injections used in aquaculture offer some limited ability to address eutrophication in connection with small-scale commercial operations, the use of electrical and mechanical forces to clean bodies of water deeper than a few feet or covering areas larger than a few acres is economically or logistically impractical. [Overview of the project] [Problems that the invention aims to solve]

[0007] The industrial sector is seeking systems to purify water to its natural state and to dissolve and transform sediments without mechanical or kinetic / electrical stimulation. [Means for solving the problem]

[0008] overview This teaching provides a groundbreaking technology for a product (i.e., a photocatalytic composite) that can enhance the natural ability of aquatic bodies to promote phytoremediation and reduce chemical oxygen demand, total organic matter content, and / or excess nutrients (e.g., phosphorus and nitrogen). This teaching may provide a new paradigm of photocatalytic phytoremediation that dramatically reduces and suppresses marine sediments without the use of exogenous microbial additives or sustained mechanical (e.g., dredging) or electrical operations. The product of this teaching may provide a rapid and scalable solution that can be optimized for application in lakes, rivers, estuaries, wetlands, rice paddies, aquaculture farms, and open ocean bodies.

[0009] This instruction demonstrates that water quality in these bodies of water can be improved through targeted delivery and activation of photocatalytic nanocomposites associated with biopolymer electrolytes. The basic technology is effective against a variety of environmental challenges and can be used in combination with other methods of large-scale water purification, as well as improving yield and quality in aquaculture.

[0010] In one embodiment, this teaching provides a photocatalytic composite material generally comprising titanium dioxide and silver nanoparticles and a polymer electrolyte that is typically less dense than water and can therefore remain suspended in water. The photocatalytic composite material may also contain other polymers, such as polyvinylpyrrolidone. The photocatalytic composite material may contain selenium and / or copper. The photocatalytic composite material also contains a solvent, thereby associating the photocatalytic material with the polymer electrolyte and other polymers as a dispersion or colloidal mixture, and for example, coating or encapsulating it therein. The photocatalytic composite material is less dense than water due to the polymer electrolyte, and thereafter the photocatalytic composite material remains suspended on or near the water surface, maintaining maximum exposure to visible light and sunlight.

[0011] More specifically, the photocatalytic composite material described herein generally comprises a TiO2-coated Ag("(TiO2)") in a polymer electrolyte such as chitosan or a chitosan substrate (CS). n Contains (TiO2) nanoparticles (Ag) nThe / Ag particles are all associated with a polyelectrolyte (e.g., chitosan or CS) in a solvent (where, merely for symbolic representation, n can be an integer greater than zero, e.g., from about 10 to about 250). (TiO2) n The / Ag particles can be further associated with another polymer. The solvent usually contains an acid.

[0012] In some embodiments, the photocatalytic composite material of the present disclosure generally comprises TiO2-coated Ag ( "(TiO2) n / Ag") nanoparticles and selenium (Se), and the (TiO2) n / Ag particles and Se are all associated with a polyelectrolyte such as chitosan in a solvent. (TiO2) n The / Ag particles and Se can be further associated with another polymer. The solvent usually contains an acid.

[0013] In some embodiments, the photocatalytic composite material of the present disclosure generally comprises TiO2-coated Ag ( "(TiO2) n / Ag") nanoparticles and copper (Cu), and the (TiO2) n / Ag particles and Cu are all associated with a polyelectrolyte such as chitosan in a solvent. (TiO2) n The / Ag particles and Cu can be further associated with another polymer. The solvent usually contains an acid.

[0014] In some embodiments, the photocatalytic composite material of the present disclosure generally comprises TiO2-coated Ag ( "(TiO2) n / Ag") nanoparticles, Se and Cu, and the (TiO2) n The / Ag particles, Se and Cu are all associated with a polyelectrolyte such as chitosan in a solvent. (TiO2) n The / Ag particles, Se and Cu can be further associated with another polymer. The solvent usually contains an acid.

[0015] In various embodiments, the photocatalytic composite material is (TiO2) n TiO2-coated AgCl ( "(TiO2) nThe material may contain particles of AgCl, which enhance the photocatalytic activity and electron transfer activity of the material. For example, a photocatalytic composite material may contain a polymer electrolyte and optionally another polymer (TiO2) in a solvent. n / Ag particles and (TiO2) n These embodiments may include AgCl particles. These embodiments may also include Se and acids.

[0016] In some embodiments, the photocatalytic composite material may include TiO2 and Se-coated Ag ("TiO2 / Ag / Se") particles, or TiO2 and / or Se-coated AgCl ("TiO2 / AgCl / Se") particles. In various embodiments, Cu may be present in these particles either in place of Se or in addition to Se.

[0017] In another embodiment, this teaching provides a method for producing a photocatalytic composite material, the method generally comprising mixing TiO2, Ag and another polymer in a first solvent to form a first mixture, wherein less than about 20% of the Ag is Ag + The process includes: exposing a first mixture to a reducing agent until it reaches a certain state to form a reduced mixture; mixing a cationic polymer electrolyte, optionally an acid, and other polymers in a second solvent to form a second mixture; and adding the second mixture to the reduced mixture to form a photocatalytic composite material.

[0018] In some embodiments, the mixing further includes mixing Se and / or Cu in a first solvent. In various embodiments, the reducing agent includes ultraviolet light, microwaves, or a combination thereof.

[0019] In another embodiment, this teaching provides a method for purifying water and / or sediment, comprising bringing a photocatalytic composite material described herein into contact with a body of water requiring purification, and exposing the photocatalytic composite material to visible light and / or sunlight for a suitable period of time and under conditions suitable for the photocatalytic composite material, to convert pollutants in the body of water into one or more different compounds. In certain embodiments, the one or more different compounds are oxidative pollutants. In various embodiments, the body of water is an open body of water. In some embodiments, the body of water is a wetland or rice paddy.

[0020] In certain embodiments, particularly in wetlands and rice paddies, the teachings provide a method for reducing methane emissions during water purification, comprising bringing a body of water into contact with a photocatalytic composite material described herein, and exposing the photocatalytic composite material to visible light and / or sunlight for a suitable period of time and under conditions suitable for the photocatalytic composite material, thereby converting methane in the body of water into one or more different compounds.

[0021] Description of the drawing Please understand that the diagrams below are for illustrative purposes only. Similar numbers generally refer to similar parts. The diagrams are not necessarily to scale and are generally intended to illustrate the principles of this instruction. The diagrams are not intended to limit the scope of this instruction. [Brief explanation of the drawing]

[0022] [Figure 1A] This is a schematic diagram of a photocatalytic composite material, which contains polymers and polymer electrolytes, namely (TiO2)n / Ag nanocomposites and (TiO2)n / AgCl nanocomposites associated with chitosan. [Figure 1B] This is a schematic diagram of a photocatalytic composite material, which contains (TiO2)n / Ag composite material and (TiO2)n / AgCl composite material associated with polymer and chitosan, along with the present Se. [Modes for carrying out the invention]

[0023] Detailed explanation This instruction describes a photocatalytic composite material that can purify water through the action of its various components. The photocatalytic composite material is formulated to be dispersed on or in water, and under natural light (e.g., visible light and / or sunlight), the photocatalytic composite material can effectively and efficiently activate the generation of ionized species and radicals that decompose harmful substances and pollutants in water, thereby reducing the chemical oxygen demand ("COD") and allowing aerobic bacteria to access the additionally available oxygen.

[0024] As oxygen becomes more readily available, aerobic bacteria compete more efficiently with BGA, consuming available phosphorus, naturally clearing the BGA bloom, expanding algal diversity, increasing oxygen utilization, and further diversifying the food chain away from the dominant consumer (i.e., BGA). The reduction in BGA naturally reduces the uptake of nitrogen oxides (NOx) into the water body, thereby clearing not only phosphorus but also nitrogen.

[0025] The photocatalytic component of the material described in this instruction is TiO2 associated with silver (Ag) nanoparticles, such that many TiO2 particles associate with Ag particles themselves. n Contains (Ag). The photocatalytic component is (TiO2) n Silver chloride particles ((TiO2)) act as a counter electrode for Ag particles. n It may also include AgCl.

[0026] In certain embodiments, the photocatalytic component also includes Se, which can assist the electron transfer process as an electron acceptor for an electron donor, Ag. In some embodiments, the photocatalytic composite material also includes Cu.

[0027] The photocatalytic composite materials described herein may also include naturally occurring polymers manipulated to retain positively charged sites (i.e., polycations) that bind to and aggregate with algal blooms and organic molecules, resulting in a clearer water column for enhanced light transmission to deeper water. Specifically, the positively charged polymer electrolytes interact with negatively charged algae and associated organic matter, causing aggregation and compaction of such structures, providing a larger pathway for light transmission and access to the photocatalytic components in the photocatalytic composite material in water. Over time, such aggregates and compactions may, in some cases, completely precipitate from the water, potentially generating further purification activity at the bottom of the water by the materials described herein.

[0028] Furthermore, the polymer electrolyte, such as chitosan, may have a lower density than water, thereby allowing the photocatalytic composite material to suspend and remain suspended in the water near the surface for extended periods, such as up to 3 days, a week, or even longer. This characteristic of the polymer electrolyte allows the photocatalytic component of the photocatalytic composite material to be exposed to visible light, particularly sunlight, generating ionic species and radicals necessary for the decomposition of unwanted substances and pollutants in the water and for the formation of an oxygen-rich, pH-neutral environment. In other words, the polymer electrolyte allows the photocatalytic composite material to suspend on or near the water surface, maximizing exposure to visible light and / or sunlight, thereby initiating the purification photocatalytic activity.

[0029] definition To facilitate understanding of the present invention, many terms and phrases are defined below.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the invention pertains. Abbreviations used herein have their conventional meanings within the art of chemistry and biology. The chemical structures and formulas described herein are constructed in accordance with the standard rules of chemical valence known in the art of chemistry.

[0031] As used herein, the terms “a” and “an” mean “one or more,” and unless otherwise appropriate from the context, include the plural.

[0032] In applications where it is stated that an element or component is included in and / or selected from the list of elements or components described, it should be understood that the element or component may be any one of the elements or components described, or the element or component may be selected from a group consisting of two or more of the elements or components described.

[0033] Furthermore, it should be understood that the elements and / or features of the compositions or methods described herein, whether expressly or implicitly, can be combined in various ways without departing from the spirit and scope of the invention. For example, where a particular compound is mentioned, that compound can be used in various embodiments of the compositions and / or methods of the invention, unless understood differently from the context. In other words, while embodiments within this application are described and depicted to enable clear and concise application, they are intended and will be understood to be able to be combined or separated in various ways without departing from the teachings and the invention. For example, it will be understood that all features described and depicted herein may be applicable to all embodiments of the invention described and depicted herein.

[0034] The phrase "at least one" should be understood to include each of the objects listed after it individually, and any various combinations of two or more of the objects, unless otherwise understood from the context and usage. The phrase "and / or" associated with three or more listed objects should be understood to have the same meaning unless otherwise understood from the context.

[0035] Including its grammatical equivalents, “include,” “includes,” “contains,” “have,” “has,” “contain,” “contains,” or “contains” should generally be understood as open-ended and non-restrictive, for example, not excluding additional elements or processes not listed unless specifically specified or understood differently from the context.

[0036] Where the term "approximately" precedes a quantitative value, the present invention also includes that specific quantitative value unless otherwise specified. As used herein, the term "approximately" means a variation of ±10% from the nominal value, unless otherwise specified or inferred from the context.

[0037] In various parts of this specification, values ​​are disclosed in groups or ranges. This specification is specifically intended to include each and all individual subcombinations of members of such groups and ranges. For example, integers in the range of 0 to 40 are specifically intended to be disclosed individually as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 and 40, and integers in the range of 1 to 20 are specifically intended to be disclosed individually as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20.

[0038] Any use of example or illustrative language in this specification, such as “etc.” or “including,” is intended merely to better illustrate the invention and does not limit the scope of the invention unless otherwise stated in the claims. The language in this specification should not be construed as indicating any element not stated in the claims that is essential for the practice of the invention.

[0039] Throughout this specification, where compositions and kits are described as having, encompassing, or containing certain components, or where processes and methods are described as having, encompassing, or containing certain steps, it is intended that there exist compositions and kits of the present invention that are essentially composed of or consist of the described components, and there exist processes and methods of the present invention that are essentially composed of or consist of the described processing steps.

[0040] As a general rule, unless otherwise specified, percentages of composition are based on weight.

[0041] Photocatalysis is an emerging technology for removing troublesome pollutants from water that needs purification. Technically, the reaction cascade involved in photocatalysis is initiated by the absorption of photons, which excite electrons from the valence band to the conduction band of a semiconductor material, thereby generating electron-hole pairs. These electron-hole pairs migrate to the material surface, where they react with the surrounding water and dissolved oxygen to form reactive oxygen species ("ROS"). These ROS are involved in the oxidation of the dissolved troublesome pollutants, resulting in the decomposition of the target contaminants into harmless by-products.

[0042] Photocatalysts with a narrower band gap are advantageous for capturing more visible light photons. Therefore, reducing the band gap of a photocatalytic material promotes greater photocatalytic activity in visible light.

[0043] This teaching can support the rapid purification of eutrophic waters by using minimal intervention and without external artificial energy sources, by introducing cohesive polymer electrolytes that improve the availability of dissolved and undissolved oxygen, precipitate colloidal and attached algae, reduce turbidity, increase the depth and rate of photosynthesis, trigger a virtuous cycle of activity - reducing COD, thereby inducing ROS, promoting the decomposition of heavy hydrocarbons and oils, then creating oxygen reachable by aerobic bacteria, stimulating dormant microorganisms, and / or promoting the efficiency of natural biological purification processes. This activity also promotes an effective reaction with a secondary effect of removing and decomposing high-density accumulated organic sludge and releasing it as a digestible food source for rapid improvement of the aquatic environment. Photocatalytic composite materials further purify and reduce ammonia and hydrogen sulfide components that pollute water and cause significant damage to aquaculture.

[0044] Photocatalytic composite materials The effects described herein are due to the presence of TiO2-coated silver ((TiO2)) in water. n This can be achieved by introducing photocatalytic composite materials such as ((TiO2) nanocomposites) so that the photocatalytic composite material floats or remains suspended near the water surface. n The / Ag nanocomposite is coated with a polymer electrolyte (e.g., chitosan). Such a photocatalytic composite can hydrolyze water at the nanoscale, generating a conveyor belt of oxygen nanobubbles, which remain in saturated water for several days, gradually dissolving and transporting newly accessible particles as a food reserve to previously suppressed natural fauna, fish, and microorganisms.

[0045] In various embodiments, the photocatalytic composite material for water purification contains TiO2 together with Ag and selenium. In particular, the photocatalytic composite material according to this teaching may include a TiO2 / Ag nanocomposite having a doping structure with Se, which provides visible light-reactive TiO2 nanoparticles. It has a broad photocatalytic range from ultraviolet light to visible light, such as sunlight, and can promote the decomposition of pollutants and contaminants in water, as well as the oxidation of heavy metals.

[0046] In various embodiments, the photocatalytic composite material is a TiO2-coated silver nanocomposite ("(TiO2) n / Ag") and TiO2-coated silver chloride ("(TiO2) n To form a nanocomposite (or "nanoelectrode"), two types of nanocomposites (e.g., Ag and AgCl) are included, for example. The photocatalytic composite is coated with a polymer electrolyte (e.g., chitosan) and another polymer. The other polymer may be PVP and / or polyethylene glycol (PEG). Although we do not wish to be constrained by any particular theory, it is thought that the other polymer prevents the TiO2-containing nanocomposite from clumping or aggregating, thereby maximizing its surface area for visible light and / or sunlight, i.e., maintaining an increased surface area of ​​the TiO2-containing nanocomposite to maximize its photocatalytic activity.

[0047] By including selenium as a doping agent, the photocatalytic composite material has a broad photocatalytic activation range from UV to visible light, while maintaining a high potential for electron transport by electron acceptors, which promotes the decomposition of pollutants in water and the oxidation of heavy metals. In addition, (TiO2) n / Ag nanocomposite and (TiO2) n The combination of / AgCl nanocomposites can provide excellent electrical properties for interfacial charge transfer and surface reactions, thereby enabling the material obtained through photocatalytic oxidation-reduction to effectively remove organic nitrogen, phosphorus, and other low-degradability contaminants and pollutants. In addition, the presence of silver imparts antibacterial properties to the photocatalytic composite material.

[0048] More specifically, in certain embodiments, the photocatalytic composite materials of this teaching for water purification generally comprise TiO2, Ag, AgCl, Se, and a polymer electrolyte binder (e.g., a mixture of chitosan and polyvinylpyrrolidone (PVP)). Refer to Figures 1A and 1B for schematic diagrams of the general chemical structures of the photocatalytic composite materials of this teaching. Figure 1A shows (TiO2) associated with polymer 10 and chitosan 20. n / Ag and (TiO2) n This shows an AgCl nanocomposite colloid.

[0049] Figure 1B is similar to Figure 1A, but includes Se associated with a TiO2-containing nanocomposite as a doping agent to promote an efficient electron transfer mechanism. These components allow TiO2-Ag nanocomposites to be formed together with TiO2-Ag-Se, TiO2-AgCl, and TiO2-AgCl-Se nanocomposites, generating doping structures in the preparation of visible light-reactive TiO2 photocatalytic compositions.

[0050] Depending on the application, photocatalytic composite materials may further contain rare or noble metals such as Au and Pt, or transition metal components such as Ni and Co, in addition to Ag and AgCl. Similar to TiO2-Ag nanocomposites containing Se, the additional metal components may take the form of nanocomposites with a doping structure.

[0051] TiO2 is generally substantially anatase-phase TiO2 (for example, at least about 80%, at least about 85%, at least about 90%, or at least about 95%, or at least about 99% is in this phase). TiO2 particles can have an average diameter of about 0.5 nm to about 20 nm.

[0052] In some embodiments, the photocatalytic composite material has a TiO2 concentration of about 25 mg / L to about 1000 mg / L, about 35 mg / L to about 500 mg / L, or about 50 mg / L to about 200 mg / L. In various embodiments, the photocatalytic composite material has a TiO2 concentration of about 100 mg / L to about 500 mg / L, or about 65 mg / L to about 250 mg / L, or about 75 mg / L to about 150 mg / L. In some embodiments, the photocatalytic composite material has a TiO2 concentration of about 100 mg / L to about 200 mg / L. In specific embodiments, the photocatalytic composite material has a TiO2 concentration of about 50 mg / L to about 200 mg / L, or about 250 mg / L, or about 325 mg / L.

[0053] In certain embodiments, the concentration of Ag in the photocatalytic composite material is approximately 5 mg / L to approximately 35 mg / L, or approximately 10 mg / L to approximately 25 mg / L, or approximately 10 mg / L to approximately 20 mg / L. In certain embodiments, the concentration of Ag in the photocatalytic composite material is approximately 5 mg / L to approximately 15 mg / L or approximately 25 mg / L.

[0054] In various embodiments, the concentration of AgClg in the photocatalytic composite material is approximately 5 mg / L to approximately 35 mg / L, or approximately 10 mg / L to approximately 25 mg / L, or approximately 10 mg / L to approximately 20 mg / L.

[0055] In some embodiments, the concentration of Se in the photocatalytic composite material is approximately 0.1 mg / L to approximately 3 mg / L, or approximately 0.2 mg / L to approximately 1.5 mg / L, or approximately 0.3 mg / L to approximately 1 mg / L.

[0056] Regarding the photocatalytic component of the photocatalytic composite material, in some embodiments, about 70% to 90% by weight of the photocatalytic component may be TiO2, and about 10% to 30% may be Ag / Se or Ag / AgCl / Se. In specific embodiments, about 80% of the photocatalytic component may be TiO2, and the remaining 20% ​​may be Ag / Se or Ag / AgCl / Se.

[0057] In photocatalytic composite materials, the amount of Ag is typically less than 10%. + This includes. In various embodiments, the amount of Ag in the photocatalytic composite material is less than about 20% or less than about 15%. + Includes. In some embodiments, Ag in the photocatalytic composite material is less than about 5% Ag + It includes. Ag particles may have an average diameter of approximately 15 nm to approximately 75 nm.

[0058] In various embodiments, the photocatalytic composite material includes a polymer electrolyte that is a cationic polymer electrolyte. The cationic polymer electrolyte may be a cationic biopolymer, such as chitosan. In some embodiments, (TiO2) n The / Ag particles are coated or encapsulated with a polyelectrolyte and, if present, another polymer.

[0059] For example, the coating may be chitosan and another polymer, such as PVP and / or PEG. Chitosan is a polymeric electrolyte used as a polymeric flocculant to aggregate suspended matter in water. It is insoluble in water and is prepared in a solvent by diluting organic or inorganic acids during production. Chitosan or any other cationic polymeric electrolyte in this teaching aggregates by electrical neutralization bonding with algae and colloidal substances in water, which are negatively charged materials. The composition reduces turbidity by agglomerating and precipitating algae and other colloidal substances. Furthermore, chitosan can maintain aggregated pollutants near photocatalytic species that can rapidly decompose them into environmentally friendly substances, thereby reducing the toxicity of water or sludge. In addition, coating photocatalytic nanocomposites with suspended polymeric electrolytes such as chitosan promotes the suspension of the nanocomposites while also preventing them from adhering to and growing harmful algae.

[0060] In various embodiments, the photocatalytic composite material has a polymer electrolyte concentration of about 0.3 g / L to about 25 g / L, or about 1 g / L to about 20 g / L or about 15 g / L, or about 5 g / L to about 10 g / L.

[0061] In certain embodiments, the concentration of other polymers in the photocatalytic composite material is about 0.001 g / L to about 25 g / L. In various embodiments, the concentration of other polymers is about 0.005 g / L to about 20 g / L. In certain embodiments, the concentration of other polymers is about 0.01 g / L to about 10 g / L. In certain embodiments, the concentration of other polymers is about 0.01 g / L to about 5 g / L.

[0062] In various embodiments, the photocatalytic composite material contains about 0.0005% to about 5% by weight of the polymer electrolyte based on the total weight of the photocatalytic composite material. In some embodiments, the photocatalytic composite material contains about 0.01% to about 3% by weight of the polymer electrolyte based on the total weight of the photocatalytic composite material. In specific embodiments, the photocatalytic composite material contains about 0.5% to about 2% by weight of the polymer electrolyte based on the total weight of the photocatalytic composite material. In some embodiments, the photocatalytic composite material contains about 0.0005% to about 1% by weight of the polymer electrolyte based on the total weight of the photocatalytic composite material. In specific embodiments, the polymer electrolyte is chitosan ((C6H 11 NO4) m ) (where m represents the symbolic representation of the polymer structure).

[0063] More specifically, chitosan is a biopolymer extracted from chitin (the main structural component of crustacean shells) and can be used as a polyelectrolyte and flocculant for agglomerating algal blooms and suspended matter in water. Chitosan material is a polycationic polymer substituted with amino groups through a chemical deacetylation reaction in chitin.

[0064] Acids such as aqueous acetic acid solutions can be used as solvents for the polymer electrolyte chitosan and also act as dispersants in aquatic environments, providing a local pH suitable for the formation and efficient growth of natural microorganisms.

[0065] In various embodiments, the solvent includes water, ethylene glycol, methylene glycol, diethylene glycol, an acid, and combinations thereof. In some embodiments, the acid is acetic acid.

[0066] In certain embodiments, the photocatalytic composite material contains about 0.001% to about 3% by weight of acid based on the total weight of the photocatalytic composite material. In some embodiments, the photocatalytic composite material contains about 0.01% to about 2% by weight of acid based on the total weight of the photocatalytic composite material. In certain embodiments, the photocatalytic composite material contains about 0.001% to about 1% by weight of acid based on the total weight of the photocatalytic composite material. In some embodiments, the acid includes or is acetic acid.

[0067] In certain embodiments, the photocatalytic composite material has a polyelectrolyte to acid weight ratio in the range of about 10:1 to about 5:4 or about 1:1 to about 4:1.

[0068] The pH of photocatalytic composite materials is typically in the range of approximately 3 to 6. In some embodiments, the pH of photocatalytic composite materials is in the range of approximately 4 to 5.

[0069] The total amount of solvent (e.g., including "first solvent" and "second solvent") in a photocatalytic composite material for water purification may be about 50% to about 99.9% by weight based on the total weight of the photocatalytic composite material. In various embodiments, the photocatalytic composite material contains about 70% to about 99.9% by weight of solvent based on the total weight of the photocatalytic composite material. In some embodiments, the photocatalytic composite material contains about 80% to about 99.9% by weight of solvent based on the total weight of the photocatalytic composite material.

[0070] In some embodiments, the weight ratio of the polymer electrolyte to the nanocomposite material (i.e., metal and metal oxide) is about 90–130:1, or about 100–120:1, or about 110:1. In certain embodiments, the weight ratio of the polymer electrolyte to the other polymer (e.g., chitosan to PVP) is about 7–9:1 or about 8:1.

[0071] In certain embodiments, the photocatalytic composite materials of this teaching may contain about 0.05 mg / L to about 5 mg / L of copper (Cu), for example, about 2 to about 3 mg / L of Cu. Although Cu is generally avoided in water purification, its presence may, if necessary, improve the antifungal and bactericidal properties of the photocatalytic composite material.

[0072] In various embodiments, when TiO2 / Cu particles are present, the concentration of Cu in the photocatalytic composite material may be about 0.5 mg / L to about 5 mg / L. In some embodiments, the amount of Cu in the photocatalytic composite material may be about 0.5 mg / L to about 7 mg / L or about 0.5 mg / L to about 3 mg / L.

[0073] In various embodiments, the photocatalytic composite materials described herein may comprise silver, titanium dioxide, chitosan, and polymers, and optionally selenium, copper, silver chloride, and acids. For example, in some embodiments, the photocatalytic composite material may comprise about 5 mg / L to about 35 mg / L of Ag, about 25 mg / L to about 1000 mg / L of TiO2, about 0.3 g / L to about 20 g / L of chitosan, and about 0.0001 g / L to about 25 g / L of polymers (e.g., PVP and / or PEG), and optionally about 0.1 mg / L to about 3 mg / L of Se, about 0.05 mg / L to about 5 mg / L of Cu, about 5 mg / L to about 35 mg / L of AgCl, and about 0.001% to about 3% by weight of an acid (e.g., acetic acid) based on the total weight of the photocatalytic composite material.

[0074] In certain embodiments, the photocatalytic composite material may contain about 5 mg / L to about 15 mg / L, or about 20 mg / L, or about 25 mg / L of Ag, about 50 mg / L to about 200 mg / L, or about 250 mg / L of TiO2, about 5 g / L to about 15 g / L of chitosan, and about 0.01 g / L to about 5 g / L of a polymer (e.g., PVP and / or PEG), and optionally about 0.3 mg to about 1 mg / L of Se, about 0.5 mg / L to about 3 mg / L of Cu, about 10 mg / L to about 20 mg / L of AgCl, and about 0.001% to about 1% by weight of an acid (e.g., acetic acid) based on the total weight of the photocatalytic composite material. Naturally, the amounts of these components may vary in the photocatalytic composite material described herein.

[0075] In some embodiments, the photocatalytic composite material may contain Ag (e.g., about 6 mg / L to about 40 mg / L), TiO2 (e.g., about 100 mg / L to about 360 mg / L), chitosan (e.g., about 0.1 g / L to about 25 g / L), and PVP (e.g., about 300 mg / L to about 2500 mg / L). The photocatalytic composite material may also contain acetic acid (e.g., about 0.01% to about 0.2%).

[0076] In certain embodiments, the photocatalytic composite material may contain Ag (e.g., about 6 mg / L to about 40 mg / L, e.g., about 10 mg / L to about 30 mg / L), TiO2 (e.g., about 100 mg / L to about 360 mg / L, e.g., about 100 mg / L to about 200 mg / L or about 200 mg / L to about 300 mg / L), Se (e.g., about 0.01 mg / L to about 5 mg / L, e.g., about 1 mg / L or about 32 mg / mL), and chitosan (e.g., about 0.1 g / L to about 25 g / L, e.g., about 1 g / L to about 10 g / L or about 1 g / L to about 15 g / L). In certain embodiments, the photocatalytic composite material may contain PVP (e.g., about 0.01 g / L to about 2.5 g / L, e.g., about 0.1 g / L to about 10 g / L or about 0.1 g / L to about 5 g / L).

[0077] In some embodiments, the photocatalytic composite material may contain Ag (e.g., about 10 mg / L to about 30 mg / L), TiO2 (e.g., about 150 mg / L to about 250 mg / L), Se (e.g., about 0.01 mg / L to about 2 mg / L), chitosan (e.g., about 5 g / L to about 15 g / L), and PVP (e.g., about 1 g / L to about 2.5 g / L).

[0078] In various embodiments, the photocatalytic composite material may contain Ag (e.g., about 6 mg / L to about 40 mg / L), TiO2 (e.g., about 100 mg / L to about 360 mg / L), Se (e.g., about 0.01 mg / L to about 5 mg / L), Cu (e.g., about 0.1 mg / L to about 5 mg / L, e.g., about 2 mg / L or about 3 mg / L) and chitosan (e.g., about 0.1 g / L to about 25 g / L). In specific embodiments, the photocatalytic composite material may contain PVP (e.g., about 300 mg / L to about 2500 mg / L).

[0079] In some embodiments, the photocatalytic composite material may contain Ag (e.g., about 10 mg / L to about 30 mg / L), TiO2 (e.g., about 150 mg / L to about 250 mg / L), Se (e.g., about 0.01 mg / L to about 2 mg / L), Cu (e.g., about 0.1 mg / L to about 3 mg / L), chitosan (e.g., about 5 g / L to about 15 g / L), and PVP (e.g., about 1000 mg / L to about 2500 mg / L).

[0080] In certain embodiments, the photocatalytic composite material may contain Ag (e.g., about 10 mg / L or about 30 mg / L), TiO2 (e.g., about 165 mg / L or about 200 mg / L), Se (e.g., about 1 mg / L or about 2 mg / L), Cu (e.g., about 2 mg / L or about 3 mg / L), chitosan (e.g., about 9 g / L or about 13 g / L), and PVP (e.g., about 1000 mg / L or about 1500 mg / L).

[0081] In some embodiments, the photocatalytic composite material may contain PEG (e.g., about 300 mg / L to about 2500 mg / L, or about 1500 mg / L, or about 750 mg / L). In certain embodiments, the photocatalytic composite material may contain PEG (e.g., about 250 mg / L to about 500 mg / L, e.g., 250 mg / L, or 350 mg / L, or 500 mg / L).

[0082] In some embodiments, the photocatalytic composite material may contain TiO2 (e.g., about 100 mg / L to about 200 mg / L), Ag (e.g., about 5 mg / L to about 15 mg / L), Se (e.g., about 0.1 mg / L to about 1.5 mg / L), Cu (e.g., about 0.1 mg / L to about 2.5 mg / L), PVP (e.g., about 300 mg / L to about 750 mg / L, or about 500 mg / L, or about 400 mg / L), PEG (e.g., about 100 mg / L to about 750 mg / L, or about 500 mg / L, or about 400 mg / L, or about 300 mg / L, or about 200 mg / L) and chitosan (e.g., about 1 g / L to about 25 g / L, or about 20 g / L, or about 15 g / L, or about 10 g / L, or about 5 g / L). In certain embodiments, the photocatalytic composite material may also contain, for example, a small amount of hydrochloric acid for the initial dissolution of TiO2 particles.

[0083] In various embodiments, this teaching provides photocatalytic composite materials comprising silver, titanium dioxide, chitosan and (another) polymer, and optionally selenium, copper, silver chloride and acid. In various embodiments, this teaching provides photocatalytic composite materials comprising silver, titanium dioxide, selenium, chitosan and (another) polymer, and optionally copper, silver chloride and acid. In some embodiments, this teaching provides photocatalytic composite materials comprising silver, titanium dioxide, selenium, copper, chitosan and (another) polymer, and optionally silver chloride and acid. In specific embodiments, this teaching provides photocatalytic composite materials comprising silver, titanium dioxide, selenium, copper, chitosan, acid and polymer, and optionally silver chloride. In specific embodiments, this teaching provides photocatalytic composite materials comprising silver, titanium dioxide, selenium, copper, chitosan, acid, (another) polymer and silver chloride. In these embodiments, the above amounts of various components described herein apply equally in this specification and elsewhere in this application.

[0084] Method for manufacturing photocatalytic composite materials In another embodiment, this teaching provides a method for producing a photocatalytic composite material. This method generally involves mixing TiO2, Ag (such as AgNO3), and another polymer in a first solvent, wherein less than 20% of the Ag is Ag + The process may include: exposing a first mixture to a reducing agent until it reaches a certain state to form a reduced mixture; mixing a cationic polymer electrolyte, optionally an acid, and other polymers in a second solvent to form a second mixture; and adding the second mixture to the reduced mixture to form a photocatalytic composite material.

[0085] The composition of the photocatalytic composite material described herein may comprise an initial solution containing TiO2, Ag, another polymer, and a first solvent, and a second solution containing a polyelectrolyte, such as chitosan, another polymer, optionally an acid, such as acetic acid, and a second solvent. Other components described herein may be present in a suitable solvent before forming the photocatalytic composite material described herein.

[0086] The first mixture contains less than 15% Ag. +, or less than 10% Ag + , or less than 5% Ag + The material is exposed to ultraviolet (UV) radiation, such as UVC radiation (e.g., around 200 nm), until it reaches a certain state. The amount of Ag+ present can be determined, for example, using UV spectroscopy at wavelengths of approximately 415 nm to 430 nm.

[0087] For example, in the production of photocatalytic composite materials, a photocatalytic nanocomposite is mixed in a first solvent containing another polymer, and a polyelectrolyte, acid, and other polymers are dissolved in a second solvent, which is then mixed together with the first mixture after it has been exposed to a reducing agent to prepare the photocatalytic composite material. The first and second solvents may contain one or more of the following: water, polyvinylpyrrolidone (PVP), monoethylene glycol (MEG), diethylene glycol (DEG), acetic acid, and combinations thereof. The first and second solvents may be the same or different and may be mixed with distilled water for hydrolysis and / or acidic gas reactions.

[0088] The total amount of the first and second solvents (also referred to herein as the “solvents” of the photocatalytic composite material) in a photocatalytic composite material for water purification may be about 50% to about 99.9% by weight based on the total weight of the photocatalytic composite material. In various embodiments, the photocatalytic composite material contains about 70% to about 99.9% by weight of the first and second solvents based on the total weight of the photocatalytic composite material. In some embodiments, the photocatalytic composite material contains about 80% to about 99.9% by weight of the first and second solvents based on the total weight of the photocatalytic composite material.

[0089] In various embodiments, the reducing agent includes ultraviolet light (e.g., UVC radiation such as 200 nm), microwaves, or a combination thereof. In certain embodiments, the mixture contains less than about 15% or about 10% by weight of Ag. + It is exposed to a reducing agent until it reaches a certain state.

[0090] In some embodiments, the mixing further includes mixing Se (such as Na2SeO4) and / or Cu (such as Cu(NO3)2·3H2O) and / or AgCl in a first solvent.

[0091] Method using photocatalytic composite materials In another embodiment, this teaching provides a method for water purification comprising bringing a photocatalytic composite material described herein into contact with a body of water requiring purification, and exposing the photocatalytic composite material to visible light and / or sunlight for an appropriate period of time and under conditions suitable for the photocatalytic composite material, thereby converting pollutant compounds in the body of water into one or more different compounds. In various embodiments, the body of water is an open body of water. In some embodiments, the body of water is a wetland or rice paddy. In certain embodiments, the body of water is an aquaculture farm.

[0092] The photocatalytic composite material in liquid form is dispersed across the water body in amounts depending on the initial state of the water, the purification goal, and various other factors. Typically, depending on the specific formulation, a high dose of the photocatalytic composite material, approximately 5 ppb of TiO2 (amount in the water body being treated), is dispersed across the water body being treated, and the amount can be injected or sprayed over the area. To homogenize the photocatalytic composite material in water, turbulence can be generated in the water using, for example, a blower or a boat's rotary motor to disperse and mix the photocatalytic composite material and accelerate the purification process.

[0093] Generally, the target TiO2 / Ag ratio is less than approximately 6 ppb in the water being purified. The target TiO2 ratio in the purified water may be less than approximately 5 ppb, and the target Ag ratio may be less than approximately 0.5 ppb. For water that does not require a high level of purification, a low dose of TiO2 of approximately 2.5 ppb is proposed. Furthermore, depending on the required level of purification, even lower doses of approximately 75%, 50%, 35%, 25%, 20%, 15%, or 10% of these amounts may be used.

[0094] When Se is present in a photocatalytic composite material, it is typically present in the photocatalytic composite material at a concentration of about 1.1 ppm or less, for example, about 1.1 ppm, about 1 ppm, about 0.9 ppm, about 0.8 ppm, about 0.7 ppm, about 0.6 ppm, about 0.5 ppm, about 0.4 ppm, about 0.3 ppm, about 0.2 ppm, or about 0.1 ppm. With respect to the amount present in the treated water, Se is present at a concentration of about 1.1 ppb or less, for example, about 1.1 ppb, about 1 ppm, about 0.9 ppb, about 0.8 ppb, about 0.7 ppb, about 0.6 ppb, about 0.5 ppb, about 0.4 ppb, about 0.3 ppb, about 0.2 ppb, or about 0.1 ppb.

[0095] This instruction may describe the amount of "effective substance" in a formulation, which is the total concentration of the active metal species present in the formulation. For example, in Example 4 below, the effective substance is the sum of 162.5 mg / L TiO2 + 10.31 mg / L Ag + 1.84 mg / L Cu + 0.94 mg / L Se, totaling 175.5 mg / L. The amount of effective substance in a formulation is typically about 100 mg / L to about 450 mg / L, or about 100 mg / L to about 350 mg / L, or about 100 mg / L to about 275 mg / L, or about 100 mg / L to about 225 mg / L. The effective amount of a formulation is considered to be 1 ppm, i.e., 1 ppm is the amount of product having an effective substance concentration of 175.5 mg / L (175.5 mg / 1000 L). In this example, 1 ppm of the product in lake water would be considered equivalent to approximately 0.1755 ppb of effective substance in the lake water (assuming 1 ppm of the product is used per 1000 L of lake water). At 2 ppm, the effective substance in the lake water would be approximately 0.356 ppb. Generally, the amount of product applied to a body of water is approximately 0.5 ppm to 2 ppm, which results in an effective substance of approximately 0.05 ppb to 0.5 ppb, 0.9 ppb to 0.4 ppb, or 0.12 ppb to 0.35 ppb in the lake water.

[0096] The amount of components contributing to the effective substance may be within the ranges described herein. For example, TiO2 is the main species or component contributing to the effective substance, for example, more than 75%, 80%, 85%, 90%, or 95% of the total effective substance. Silver, copper, and selenium may also be included in the effective substance, but in significantly smaller amounts. For example, silver may be present in an amount of about 5% to about 10% of the amount of TiO2, copper may be present in an amount of about 0.5% to about 2.5% of the amount of TiO2, and selenium may be present in an amount of about 0.01% to about 1% of the amount of TiO2.

[0097] The photocatalytic composite material spreads in water and floats on or near the water surface. When exposed to sunlight or other visible light, the photocatalytic composite material begins to generate free hydroxyl ions and radicals adjacent to pollutants and contaminating compounds in the water, oxidizing undesirable species and resulting in their decomposition and / or removal. While not wishing to be bound by a specific theory, the action of the photocatalytic composite material also generates oxygen and hydroxyl ions as microbubbles in the water, and these microbubbles come into contact with gases and microorganisms, degassing and killing the microorganisms. Furthermore, the silver present in the photocatalytic composite material also acts as an antimicrobial agent that assists in the purification process. In addition, the oxygen generated in the water allows for the growth of aerobic bacteria.

[0098] Treatment with photocatalytic composite materials may be performed daily, every two days, every three days, every four days, every five days, every six days, once a week, or less frequently. Since the suspension period of photocatalytic composite materials tends to be about 3 to 7 days, treatment every other week or weekly is common practice.

[0099] The results of water purification can be measured by various parameters. For example, the amounts of the following parameters can be measured before and after treatment (including intermediate treatments to monitor progress): BGA in water, chlorophyll in water (phytoplankton biomass), water clarity, total suspended solids ("TSS") in water, BOD in water, pH of water, total nitrogen in water, total phosphorus in water, total nitrogen in sediment, total phosphorus in sediment, total organic matter in sediment, and total organic carbon in sediment. These parameters are measured using industry-standard analytical techniques, which may include portable instruments for measurement in this field. For example, a reduction of at least 60% or at least 70% of BGA in a water body can be achieved in about six weeks with weekly treatment.

[0100] Furthermore, particularly with respect to wetlands and rice paddies, this teaching provides a method for reducing methane emissions during water purification, comprising bringing a body of water into contact with a photocatalytic composite material described herein, and exposing the photocatalytic composite material to visible light and / or sunlight for an appropriate amount of time and under conditions suitable for the photocatalytic composite material, thereby converting methane into one or more of hydrogen, water, and carbon dioxide. [Examples]

[0101] Examples Example 1. Manufacturing of photocatalytic composite material A photocatalytic composite material was prepared by mixing 1.5 L of PVP (1.8 g / L in water) dissolved in water, 100 mL of AgNO3 (62.8 g / L in water) dissolved in water, and 200 mL of TiO2 (200 g / L acidic water-based anatase TiO2) in 98.2 L of distilled water at room temperature to form a first mixture. The first mixture was exposed to UVC radiation at approximately 200 nm for approximately 3 hours to provide a reduced mixture.

[0102] Separately, 2500g of chitosan was mixed with 1L of acetic acid and 0.2L of PVP (1.8g / L) in distilled water to form a second mixture. The second mixture was added to the reducing mixture while stirring at ambient temperature to form a photocatalytic composite material.

[0103] During this process, chitosan and PVP are thought to either associate with the TiO2 / Ag nanocomposite or encapsulate the TiO2 / Ag nanocomposite to form the final photocatalytic composite material in the solution.

[0104] Example 2. Water purification test #1 The NY Center for Clean Water Technology of Stony Brook University conducted a water purification test to evaluate the purification of BGA, nitrogen, and phosphorus from water and sediment from Lake Agawam, which was designated as the second most polluted lake in New York State at the time of the test. The test period was four weeks.

[0105] Twelve transparent 20L containers were used. Four containers were used with a low dose of photocatalytic composite material, four with a high dose of photocatalytic composite material, and four were designated as controls. 1000g of mixed sludge from the lake bottom was added to each container, followed by 10L of lake water, a fish ball aerator, and three minnows of two different types (six fish in each container).

[0106] The photocatalytic composite material from Example 1 was used in this experiment. The photocatalytic composite material was dispersed in each container so that the TiO2 concentration in each container was 5 ppb for the high dose and 2.5 ppb for the low dose (no photocatalytic composite material was added to the control). The same amount was added to each container weekly. The containers were exposed to natural light at ambient ambient temperature.

[0107] The hypothesis to be tested was whether photocatalytic composite materials are an effective tool for reducing BGA levels and regulating the natural carbon and nitrogen cycles. The hypothesis was tested by observing measurements of BGA content in water, nitrogen content in water, phosphorus content in water and sediment, total phytoplankton (chlorophyll a) biomass, total suspended solids, biological oxygen demand, and pH.

[0108] The results were successful in all measurements, including a statistically significant reduction in fish mortality.

[0109] More specifically, over the course of the 28-day (4-week) study period, the reduction in BGA was approximately 60% with the low-dose treatment and approximately 72% with the high-dose treatment compared to the control group.

[0110] Total phytoplankton biomass (chlorophyll a) decreased by approximately 27% with low-dose treatment and by over 37% with high-dose treatment compared to the control. This result supports the illustration of how photocatalytic composite materials purify excess nutrients in water by supporting the natural purification cycle and thereby promoting the consumption of microalgae.

[0111] The total nitrogen in the water decreased by approximately 17% at low doses and approximately 28% at high doses compared to the control.

[0112] Total phosphorus in the water decreased by approximately 28% at low doses and approximately 34% at high doses compared to the control. Phosphorus in the sediment decreased by approximately 32% at low doses and approximately 44% at high doses compared to the control. These results demonstrate phosphorus purification that reduces algal bloom and removes organic sediment without dredging. In other words, the photocatalytic composite material does not act as a masking agent that encapsulates phosphorus in the sediment, but rather releases excess phosphorus trapped in the sediment, thereby promoting purification and reducing total phosphorus.

[0113] Furthermore, the photocatalytic composite material can restore water bodies to a sustainable equilibrium state, as demonstrated by changes in water pH. The control pH was approximately 6.5 after 4 weeks, while the water treated with a low dose had a pH of approximately 6.8, and the water treated with a high dose had a pH of approximately 7, which was neutral.

[0114] Total suspended solids decreased by approximately 22% with low-dose treatment and approximately 33% with high-dose treatment compared to the control. Treatment with the photocatalytic composite material rapidly improved the visibility of water samples, restored the depth or range of photosynthesis, and reduced harmful algae and sediment.

[0115] Biological oxygen demand (BOD) decreased by approximately 8% with low-dose treatment and approximately 42% with high-dose treatment compared to the control. The reduction in BOD during nitrogen and phosphorus treatment is a strong indicator of sustainable lake purification.

[0116] Example 3 - Water Purification Test #2 The NY Center for Clean Water Technology of Stony Brook University conducted a mesocosm water purification test, evaluating the purification of BGA, nitrogen, and phosphorus from water and sediment from Lake Agawan, which was designated as the second most polluted lake in New York State at the time of the test. The test period was seven weeks.

[0117] Eight 300L containers were used, with four containers treated with a high dose of photocatalytic composite material and four containers designated as controls. 7 kg of mixed sludge from the lake bottom was added to each container, followed by 300L of lake water and 20 juvenile minnows of two different species (40 fish in each container) (10 minnows in the cages being accessed).

[0118] The photocatalytic composite material from Example 1 was used in this experiment. Each container, excluding the control, was treated weekly to provide 5 ppb of the product TiO2 in the lake water being tested. The containers were exposed to natural light at the ambient temperature of the lake water so that they were in contact with the lake water and their upper surfaces.

[0119] The experimental results are shown in Table 2, and the improvement rate of lake water purification using the photocatalytic composite material described in this instruction was quite significant for many parameters.

[0120] [Table 1]

[0121] Example 4 - Water purification, removal of sediment nutrients, and reduction of sediment A 1-liter (L) photocatalytic composite material was prepared by mixing polyvinylpyrrolidone (PVP) (380 mg) and polyethylene glycol (PEG) (380 mg) with approximately 987.5 mL of water at ambient temperature to provide mixture A.

[0122] Mixture B was prepared by mixing 2500 mg of TiO2 solution (10% dispersed in 25 mL (37%) HCl and water), AgNO3 (25 mg dissolved in 4.975 mL of distilled water), copper nitrate trihydrate (Cu(NO3)2·3H2O) (10.80 mg dissolved in 4.990 mL of distilled water), and sodium selenite (Na2SeO4) (3.16 mg dissolved in 4.997 mL of distilled water) over 24 hours. Mixture A was mixed with mixture B to provide 1 L of mixture C. Mixture C was mixed and Ag was converted to Ag + The conversion rate is approximately 90% (i.e., Ag + The mixture was exposed to ultraviolet light until less than approximately 10% by weight remained in mixture C.

[0123] Separately, 25 g of chitosan was mixed with 10 mL of acetic acid and 2 mL of PVP (1.8 g PVP / L (water)) in 988 mL of distilled water to form mixture D.

[0124] 650 mL of mixture C was added to 350 mL of mixture D to form 1 L of the final product, i.e., a photocatalytic composite material.

[0125] The effective amount of substance in this formulation, taking its concentration into account, is approximately 175.5 mg / L (i.e., 162.5 mg / L TiO2 + 10.31 mg / L Ag + 1.84 mg / L Cu + 0.94 mg / L Se), which is considered to be 1 ppm or approximately 1755 ppb in lake water. At 2 ppm, the effective amount of substance in lake water is approximately 0.356 bbp.

[0126] A total of 15 ppm of the final product was added to a natural lake over 13 weeks, with 2 ppm / week added for the first 3 weeks, 1 ppm / week for the next 7 weeks, and 0.7 ppm / week for the following 3 weeks. The lake was approximately 4 acres in size and had a depth of 1–13 feet. Assuming an average depth of approximately 7 forts, the total volume of the lake was estimated to be approximately 28 acre-feet or 34,500 cubic meters. Therefore, 60 L / week of the final product was added to the lake for the first 3 weeks, 30 L / week for the next 7 weeks, and 20 L / week for the following 3 weeks (as specified herein, the effective substance present in the lake water at approximately 2 ppm was approximately 0.31 bpp. However, it is difficult to accurately determine the concentration of the effective substance present in lake water where the volume of water is unknown).

[0127] The following results were obtained from both the removal of sediment nutrients and the purification of water. The data in Table 3 below shows that algal diversity develops on a weekly basis during the treatment of natural lakes.

[0128] [Table 2]

[0129] At 12 weeks, an increase in diversity occurs, while overall algae and BGA decrease.

[0130] Table 4 shows the average diversity of different algae species.

[0131] [Table 3]

[0132] Furthermore, the decomposition of sediments and the increase in sediment depth resulted in a 50% reduction in total nitrogen, which promotes a more active food chain in the environment. Measurement sampling was carried out at three specific locations in the lake, and three samples were taken for measurement at each location. Total phosphorus measurements were based on the EPA pre-sulfurization method. Table 5 shows the results of these measurements.

[0133] [Table 4]

[0134] Reference This application references various issued patents, published patent applications and other publications, all of which are incorporated herein by reference. In the event of any conflict between any of the incorporated references and this specification, this specification shall prevail. Furthermore, any particular embodiment of this disclosure in the prior art may be expressly excluded from any one or more of the claims. Such embodiments may be excluded even if the exclusion is not stated herein, as they are considered to be known to those skilled in the art. Any particular embodiment of this disclosure may be excluded from any claim for any reason, whether or not it relates to the existence of the prior art.

[0135] Equal portions This disclosure can be embodied in other specific forms without departing from its spirit or essential features. Therefore, the embodiments described above should be considered illustrative in all respects and not limitations of the disclosure as described herein. Accordingly, the scope of this disclosure is indicated not by the foregoing specification but by the appended claims, encompassing all modifications that fall within the equivalent meaning and scope of the claims.

Claims

1. TiO ２ Coated Ag("(TiO ２ ) ｎ A photocatalytic composite material containing particles of / Ag, wherein the TiO ２ Ag particles are a photocatalytic composite material that associates with polymer electrolytes in a solvent.

2. The above (TiO ２ ) ｎ The photocatalytic composite material according to claim 1, wherein the Ag particles are further associated with another polymer.

3. The photocatalytic composite material according to claim 1 or 2, further comprising selenium (Se).

4. TiO ２ Coated AgCl(TiO) ２ A photocatalytic composite material according to any one of claims 1 to 3, further comprising AgCl particles.

5. TiO ２ and Se-coated Ag (TiO ２ / Ag / Se) particles and TiO ２ and Se-coated AgCl (TiO ２ / AgCl / Se) particles, the photocatalytic composite material according to claim 3 or 4.

6. The TiO ２ This is essentially the anatase phase TiO ２ A photocatalytic composite material according to any one of claims 1 to 5, comprising:

7. The aforementioned silver (Ag) is less than 10% Ag ＋ A photocatalytic composite material according to any one of claims 1 to 6, comprising:

8. The photocatalytic composite material according to any one of claims 1 to 7, wherein the polymer electrolyte has a lower density than water, and as a result, the photocatalytic composite material floats or remains suspended in water.

9. The photocatalytic composite material according to any one of claims 1 to 8, wherein the polymer electrolyte is a cationic biopolymer.

10. The photocatalytic composite material according to claim 9, wherein the cationic biopolymer is chitosan.

11. The photocatalytic composite material according to any one of claims 2 to 10, wherein the other polymer is polyvinylpyrrolidone.

12. The above (TiO ２ ) ｎ The photocatalytic composite material according to any one of claims 1 to 11, wherein the / Ag particles are coated and / or encapsulated by the polymer electrolyte.

13. The above (TiO ２ ) ｎ The photocatalytic composite material according to any one of claims 2 to 11, wherein the / Ag particles are coated and / or encapsulated by the polymer electrolyte and the other polymer.

14. The above (TiO ２ ) ｎ / Ag particles and the (TiO ２ ) ｎ The photocatalytic composite material according to any one of claims 4 to 11, wherein AgCl particles are coated and / or encapsulated with a polymer electrolyte.

15. The above (TiO ２ ) ｎ / Ag particles and the (TiO ２ ) ｎ The photocatalytic composite material according to any one of claims 4 to 11, wherein the / Ag particles are coated and / or encapsulated by the polymer electrolyte and the other polymer.

16. The photocatalytic composite material according to any one of claims 1 to 15, wherein the Ag particles have an average diameter of about 15 nm to about 75 nm.

17. The TiO ２ The photocatalytic composite material according to any one of claims 1 to 16, wherein the particles have an average diameter of about 0.5 nm to about 20 nm.

18. The photocatalytic composite material according to claim 17, wherein the solvent comprises water, ethylene glycol, methylene glycol, diethylene glycol, and an acid.

19. The photocatalytic composite material according to claim 18, wherein the acid is acetic acid.

20. The photocatalytic composite material according to any one of claims 1 to 19, comprising about 0.0005% by weight to about 5% by weight of the polymer electrolyte based on the total weight of the photocatalytic composite material.

21. A photocatalytic composite material according to any one of claims 1 to 19, comprising about 0.05% to about 2% by weight of the polymer electrolyte based on the total weight of the photocatalytic composite material.

22. The photocatalytic composite material according to any one of claims 1 to 21, comprising about 50% to about 99.9% by weight of the solvent based on the total weight of the photocatalytic composite material.

23. The photocatalytic composite material according to any one of claims 18 to 22, comprising about 0.001% to about 3% of the acid based on the total weight of the photocatalytic composite material.

24. The photocatalytic composite material according to any one of claims 18 to 23, wherein the weight ratio of the polymer electrolyte to the acid is in the range of about 10:1 to about 5:

4.

25. The photocatalytic composite material according to any one of claims 1 to 24, wherein the concentration of the polymer electrolyte is about 8 g / L to about 20 g / L.

26. The TiO ２ The photocatalytic composite material according to any one of claims 1 to 25, wherein the concentration is approximately 50 mg / L to approximately 1000 mg / L.

27. The photocatalytic composite material according to any one of claims 1 to 26, wherein the concentration of Ag is about 5 mg / L to about 35 mg / L.

28. The photocatalytic composite material according to any one of claims 2 to 27, wherein the concentration of the other polymer is about 0.01 g / L to about 5 g / L.

29. The photocatalytic composite material according to any one of claims 3 to 28, wherein the concentration of Se is approximately 0.05 mg / L to approximately 3 mg / L.

30. The photocatalytic composite material according to any one of claims 3 to 28, wherein the concentration of Se is about 0.1 mg / L to about 2 mg / L.

31. A photocatalytic composite material according to any one of claims 1 to 30, further comprising copper (Cu).

32. The photocatalytic composite material according to claim 31, wherein the concentration of Cu is approximately 0.5 mg / L to approximately 7 mg / L.

33. The photocatalytic composite material according to claim 31, wherein the concentration of Cu is approximately 0.5 mg / L to approximately 3 mg / L.

34. silver, Titanium dioxide, Chitosan, and Polyvinylpyrrolidone A photocatalytic composite material containing [the specified material].

35. The photocatalytic composite material according to claim 34, further comprising acetic acid and water.

36. The photocatalytic composite material according to claim 34 or 35, further comprising one or more of silver chloride, copper, and selenium.

37. silver, Titanium dioxide, Selenium, and Chitosan A photocatalytic composite material containing [the specified material].

38. The photocatalytic composite material according to claim 37, further comprising one or more copper and polyvinylpyrrolidone.

39. silver, Titanium dioxide, selenium, Copper, and Chitosan A photocatalytic composite material containing [the specified material].

40. The photocatalytic composite material according to claim 39, further comprising polyvinylpyrrolidone.

41. A method for producing a photocatalytic composite material, TiO in the first solvent ２ The process involves mixing Ag and another polymer to form a first mixture, Approximately less than 20% of the aforementioned Ag is Ag ＋ The first mixture is exposed to a reducing agent until it reaches a certain state, forming a reduced mixture. The process involves mixing a cationic polymer electrolyte, an acid, and the other polymers in a second solvent to form a second mixture. The second mixture is added to the reducing mixture to form a photocatalytic composite material. A method that includes this.

43. The method according to claim 41, wherein the mixing further comprises mixing Se and / or Cu in the first solvent.

43. The method according to claim 41 or 42, wherein the reducing agent includes ultraviolet light, microwaves, or a combination thereof.

44. Less than 10% by weight of the aforementioned Ag is Ag ＋ The method according to any one of claims 41 to 43.

45. A method of water purification, Bringing a photocatalytic composite material according to any one of claims 1 to 30 into contact with a body of water that requires purification, Exposing the photocatalytic composite material to visible light and / or sunlight for an appropriate period of time and under conditions suitable for the photocatalytic composite material to convert the polluting compounds in the water body into one or more different compounds. A method that includes this.

46. The method according to claim 45, wherein the one or more different compounds are oxidative contaminants.

47. The method according to claim 45, wherein the body of water is an open body of water, a wetland, or a rice paddy.

48. The method according to any one of claims 45 to 47, wherein oxygen is produced in the aquatic body, enabling aerobic bacteria to grow.

49. A method for reducing methane emissions during water purification, Bringing a body of water into contact with the photocatalytic composite material described in any one of claims 1 to 40, Exposing the photocatalytic composite material to visible light and / or sunlight for an appropriate period of time and under conditions suitable for the photocatalytic composite material to convert methane in the water body into one or more different compounds. A method that includes this.

50. The method according to any one of claims 45 to 49, comprising bringing a fresh, unused photocatalytic composite material into contact with the water body multiple times over a period of time.

51. The decrease in cyanobacteria in the aforementioned body of water, The decrease in total phytoplankton biomass (chlorophyll a) in the aforementioned water body, Increased biodiversity in phytoplankton communities, Increase in the transparency of the water in the aforementioned body, The decrease in total suspended solids in the aforementioned body of water, The decrease in the chemical oxygen demand in the aforementioned body of water, The decrease in total nitrogen in the aforementioned body of water, The decrease in total phosphorus in the aforementioned body of water, The decrease in total nitrogen in the sediments beneath the aforementioned body of water, The decrease in inorganic nitrogen in the sediments beneath the aforementioned water body, The decrease in total phosphorus in the sediments beneath the aforementioned body of water, The decrease in total organic matter in the sediments beneath the aforementioned water body, The decrease in total organic carbon in the sediments beneath the aforementioned body of water, An increase in the pH of the aforementioned body of water, and Decrease in the sediment in the water body The method according to any one of claims 45 to 49 or 50, which results in one or more of the above.

52. The method according to claim 51, wherein the pH obtained in the water body is about 7.

53. The method according to any one of claims 45 to 48 or 50, wherein the photocatalytic composite material aggregates with algal bloom and / or negatively charged polluting compounds and pollutants, thereby reducing the turbidity of the water body.

54. The method according to any one of claims 50 to 53, comprising bringing a fresh, unused photocatalytic composite material into contact with the water body once a week for four weeks, once a week for six weeks, twice a week for four weeks, twice a week for six weeks, or once or twice a week for more than six weeks, multiple times over a certain period of time.

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