Chemical type selection method, program therefor, and recording medium

Abstract

The present invention provides a method for efficiently and systematically selecting a chemical type recommended for use in a water treatment plant on the basis of the composition of adhered matter on a separation membrane element. Provided is a method for selecting a chemical type to be used in a water treatment plant, the method comprising: estimating the abundance ratio of at least each main component contained in adhered matter collected from inside the water treatment plant, the abundance ratio being estimated from analysis results and / or measurement results representing the abundance amount, in the adhered matter, of at least one from among elements, ions, and chemical structures contained in the adhered matter; calculating cumulative recommendation degrees for the adhered matter of a plurality of chemical types on the basis of the estimation result of the abundance ratio of each component and a correspondence index indicating a recommendation degree for each component of the plurality of chemical types to be used in the water treatment plant; and selecting at least one chemical type on the basis of a comparison of magnitudes between the cumulative recommendation degrees.

Description

A method for selecting drug types, a program for that method, and a recording medium.

[0001] This invention relates to a method for selecting chemical types used in a water treatment plant, a program for the same, and a recording medium.

[0002] In recent years, separation technologies for mixtures using separation membranes such as reverse osmosis membranes, nanofiltration membranes, ultrafiltration membranes, and microfiltration membranes have attracted attention as high-precision, energy-saving processing processes, and their use in various water treatment applications is expanding. For example, in reverse osmosis separation using a reverse osmosis membrane, a solution containing solutes such as salt is passed through the reverse osmosis membrane at a pressure higher than the osmotic pressure of the solution, thereby obtaining a liquid with reduced solute concentration. For this reason, it is widely used in the desalination of seawater and brine, the production of ultrapure water, and the concentration and recovery of valuable substances.

[0003] In plants utilizing such separation membranes, deposits known as fouling can occur. Fouling can cause various operational and performance problems in water treatment plants, such as increased differential pressure and reduced membrane performance. Various chemicals can be used to resolve, improve, or prevent these problems. It is important to select the appropriate chemical type based on the type of deposit, as well as the method of chemical addition, including the amount and timing of addition.

[0004] For example, Patent Documents 1 and 2 describe technologies related to scale inhibitors that suppress the occurrence of a specific type of inorganic fouling. The amount and concentration of such chemicals to be added are generally determined by calculating the scale generation risk from the inorganic element and / or ionic composition of the water to be treated and the operating conditions of the water treatment plant. On the other hand, the type of scale inhibitor to be used is generally determined by estimating the main separation membrane fouling substances that may occur from the inorganic element and / or ionic composition of the water to be treated, and then determining the main separation membrane fouling substances that have been estimated. This method is not limited to scale inhibitors but is also applicable to other deposits and chemicals. For example, if there is a lot of biofouling, which is biological fouling, disinfectants and biological growth inhibitors are suitably used.

[0005] Japanese Patent Publication No. 2012-183472, International Publication No. 2012 / 114953

[0006] However, deposits generated in actual water treatment plants are almost always complexes of a wide variety of substances. Therefore, conventional methods that focus on specific deposits and qualitatively determine the recommended type of chemical have made it difficult to select the appropriate chemical. For example, if multiple inorganic substances are present in the deposit and different types of scale inhibitors are recommended for each inorganic substance, it is difficult to determine which scale inhibitor to use.

[0007] Furthermore, as mentioned above, the determination of the type of chemical often relies on the analysis and / or measurement results of water samples taken from the treated water, concentrated water, and other water treatment plant piping. However, a problem arose in that the amount and concentration of elements and / or ions originating from or causing the formation of deposits in such water samples were below the detection limits of various analytical methods, making it impossible to determine the type of chemical to use. Moreover, the composition of elements and / or ions in the water sample sometimes differed from the composition in the deposits. In such cases, the chemicals selected based on the analysis and / or measurement results of the water sample had little effectiveness against the deposits, resulting in a problem of limited effectiveness in resolving, improving, or preventing problems caused by deposits in water treatment plants.

[0008] Therefore, the object of the present invention is to provide a method for efficiently and systematically selecting the types of chemicals recommended for use in a water treatment plant based on the composition of deposits collected from within the water treatment plant.

[0009] To solve the above problems, the present invention has the following features: [1] A method for selecting types of chemicals to be used in a water treatment plant, comprising: estimating the abundance ratio of at least one element, ion, and chemical structure contained in the deposits collected from the water treatment plant from analytical results and / or measurement results representing the abundance of at least one of these elements, ions, and chemical structures in the deposits; calculating a cumulative recommendation score for the deposits of the multiple chemicals to be used in the water treatment plant based on the estimated abundance ratio of each component and a corresponding index indicating the recommendation score for each of the multiple chemicals to be used in the water treatment plant; and selecting at least one type of chemical based on a comparison of the magnitudes of the cumulative recommendation scores. [2] The method for selecting types of chemicals according to [1], wherein in calculating the cumulative recommendation score, a score obtained by accumulating the product of the estimated abundance ratio of each component and the recommendation score for each component is used. [3] A method for selecting a type of chemical according to [1] or [2], wherein, in estimating the abundance ratio of each component, if an oxide is included in each component, the abundance ratio of the oxide is estimated based on analytical results and / or measurement results representing the amount of metal elements contained in the oxide in the deposit. [4] A method for selecting a type of chemical according to [1] or [2], wherein, in estimating the abundance ratio of each component, if an inorganic salt is included in each component, the abundance ratio of the inorganic salt is estimated based on analytical results and / or measurement results representing the amount of at least one cation, anion, and element constituting the inorganic salt in the deposit. [5] A method for selecting a type of chemical according to [1] or [2], wherein the analytical results and / or measurement results represent the amount of at least one element or ion described in A to G below in the deposit.A. Silicon B. Calcium C. Aluminum and / or iron D. Copper, manganese, iron E. At least one of cobalt, nickel, zirconium, fluorine, barium, and strontium F. Phosphorus G. At least one of sulfate ions, carbonate ions, and phosphate ions [6] A method for selecting the type of chemical according to [1] or [2], wherein the analysis result and / or measurement result represents the amount of at least one of the chemical structures described in A to F below present in the deposit. A. Ether bond B. Ester bond C. Amide bond D. Sulfonyl bond E. Aromatic carbon-carbon double bond F. Phosphorus-oxygen bond [7] A method for selecting a type of chemical according to [1] or [2], wherein the analysis result and / or measurement result is any of the following: the amount of at least one element, ion, and chemical structure contained in the deposit, the amount of substance per unit area of ​​the deposit region of the deposit, the amount of substance per dry weight of the deposit, or the content ratio in the deposit. [8] A method for selecting a type of chemical according to [7], wherein the analysis result and / or measurement result is the amount of substance of the element and / or ion contained in the deposit per dry weight of the deposit. [9] A method for selecting a type of chemical according to [1] or [2], in estimating the abundance ratio of each component, to calculate the ratio of inorganic matter to organic matter in the deposit, using at least one of the analysis results described in A to C below: A. Ash content B. Ratio of total amount of metal elements to amount of carbon C. A method for selecting chemical types according to [1] or [2], wherein the ratio of metallic bonds and metal-oxygen bonds to any functional group containing carbon elements

[10] A method for selecting chemical types according to [1] or [2], wherein the influence of chemicals already used is taken into consideration by performing calculation processing based on the type and / or concentration of chemicals already used in the water treatment plant on at least one of the analysis results and / or measurement results and the estimated results of the abundance ratio of each component

[11] A method for selecting chemical types according to [1] or [2], wherein the corresponding index is determined from the results of chemical tests using multiple types of chemicals on a separation membrane element or separation membrane to which any deposit is attached, and is a corresponding index that indicates the degree of recommendation of the multiple types of chemicals for each component that may be contained in the deposit.

[12] A method for selecting chemical types according to [1] or [2], wherein the degree of recommendation in the corresponding index is a qualitative index, the score of the qualitative index indicating that use is not recommended is set to 0, the score of the qualitative index with the highest degree of recommendation is set to the number of levels of the qualitative index indicating the degree of recommendation, the scores of other qualitative index indicating that it is recommended are set to be smaller than the score of the qualitative index with the highest degree of recommendation, and to be larger the greater the degree of recommendation indicated by the original qualitative index, and are used as the degree of recommendation for each component.

[13] A method for selecting chemical types according to [1] or [2], wherein the deposit is a deposit taken from one of the following: plant piping, pretreatment filter, separation membrane element, and water passage member.

[14] A method for selecting chemical types according to

[13] , wherein the deposit is taken from a separation membrane element installed on the upstream or downstream side in a water treatment plant.

[15] A method for selecting chemical types according to

[14] , wherein the deposit is a deposit taken from the surface of the separation membrane.

[16] The method for selecting chemical types according to [1] or [2], wherein the chemical used in the water treatment plant is at least one of a scale inhibitor, a cleaning agent, a cleaning aid, and a disinfectant.

[17] A program for selecting chemical types used in a water treatment plant, the program causing a computer to function as: a data input means for inputting data relating to the analysis results and / or measurement results of deposits collected from within the water treatment plant into the computer; a data recording means for recording the data and a corresponding index indicating the degree of recommendation for each component that may be contained in the deposits for a plurality of chemical types used in the water treatment plant; a means for estimating the abundance ratio of each component contained in the deposits from the analysis results and / or measurement results; a means for calculating the cumulative recommendation degree of the plurality of chemical types for the deposits based on the estimated abundance ratio of each component and the corresponding index; and a means for selecting and outputting at least one or more chemical types based on a comparison of the magnitudes of the cumulative recommendation degrees.

[18] The program according to

[17] , further comprising means for performing calculation processing based on the type and / or concentration of chemicals already used in the water treatment plant on at least one of the analysis results and / or measurement results and the estimated ratio of each component, and taking into account the influence of the chemicals already used.

[19] A computer-readable recording medium recording the program according to

[16] or

[17] .

[0010] According to the present invention, the appropriate type of chemical can be selected more efficiently and systematically than conventional methods, depending on the composition of the deposits collected from within the water treatment plant. As a result, countermeasures against problems caused by separation membrane fouling can be implemented quickly and easily.

[0011] This shows an example of a water treatment plant flow. This is an example of a program for executing the chemical type selection method of the present invention on a computer.

[0012] Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following description and can be modified and implemented as appropriate without departing from the spirit of the invention.

[0013] In embodiments of the present invention, the relative abundance of at least one of the elements, ions, and chemical structures contained in the deposits collected from the water treatment plant is estimated from analytical and / or measurement results representing the amount of each component present in the deposits. Furthermore, based on the estimated relative abundance of each component and a corresponding index indicating the degree of recommendation for each of the multiple chemical types used in the water treatment plant for each of the components, the cumulative recommendation degree for the multiple chemical types for the deposits is calculated, and at least one or more chemical types are selected based on a comparison of the magnitudes of the cumulative recommendation degrees.

[0014] <Subject of Analysis and / or Measurement> In embodiments of the present invention, the deposits that are the subject of analysis and / or measurement are a general term for deposits collected from within a water treatment plant, and are not particularly limited as long as they are deposits collected from various components constituting the water treatment plant. Examples of sources from which deposits are collected include piping of the water treatment plant, various filters such as pre-treatment filters, separation membrane elements, and water passage members. Of these, it is preferable to use deposits collected from the separation membrane element (hereinafter referred to as separation membrane element deposits). Separation membrane element deposits refer to deposits inside and outside the separation membrane element, or deposits present on or inside the separation membrane within the separation membrane element, and include deposits present on the separation membrane surface and / or inside the separation membrane, as well as deposits on the end face and outside of the separation membrane element. Of these, from the viewpoint of analysis and measurement sensitivity, deposits on the end face or surface of the separation membrane element are preferably used, and deposits on the surface of the separation membrane are more preferably used.

[0015] For analysis and measurement purposes, when collecting deposits from the separation membrane element, methods such as physically collecting the deposits from the separation membrane element or the surface of the separation membrane can be used.

[0016] There are no particular restrictions on the method of physically collecting deposits on the separation membrane element. For example, one method involves immersing the membrane in pure water and dispersing the deposits in the pure water by ultrasonic pulverization for collection. Another method for collecting deposits on the separation membrane element with a high recovery rate is to collect the deposits with a wiping tool, and then immerse the wiping tool in pure water to disperse and collect the deposits in the pure water. The wiping tool is not particularly limited, but examples include cotton swabs, spatulas, scrapers, rubber spatulas, etc. From the viewpoint of analytical accuracy, it is preferable to use a tool that does not contain an oxidizing agent-based disinfectant. When collecting deposits on the separation membrane surface, cotton swabs or silicone tools are preferably used to prevent contamination of the separation membrane due to damage or peeling. The pure water used should preferably be distilled water, reverse osmosis membrane water and ion-exchanged water immediately after purification, or commercially available ultrapure water.

[0017] When physically collecting deposits from the surface of a separation membrane, it is preferable to measure the weight of the collected deposits. In particular, it is preferable to measure the weight after drying. Furthermore, from the viewpoint of quantitative accuracy, it is preferable to collect from a separation membrane of an arbitrary specified area and measure the amount of deposits per specified area and / or per unit area. For example, 1 m ２ Dry deposit amount per unit (g-dry / m ２ This can be measured directly or calculated.

[0018] In embodiments of the present invention, the separation membrane is a semipermeable membrane that allows some components of the water to be treated, such as the solvent, to pass through, but prevents solute components such as salt from passing through. Examples include microfiltration membranes (MF), ultrafiltration membranes (UF), nanofiltration membranes (NF), and RO membranes. Of these, embodiments of the present invention are particularly suitable for semipermeable membranes used in applications such as desalination of seawater and brine, production of industrial water, concentration of fruit juices, and advanced treatment in water supply systems, such as NF membranes and RO membranes.

[0019] While the shape and material of the separation membrane are not particularly limited, a composite material in which a separation function layer is formed on a microporous support layer is an example.

[0020] Separation membranes are generally used as elements with a shape appropriate to the membrane configuration. A separation membrane element is not particularly limited as long as it has substantial liquid chambers on both sides of the separation membrane and allows pressurized liquid to be permeated from one surface to the other. Multiple separation membrane elements can also be used connected in series or parallel.

[0021] Separation membrane elements are used in various shapes depending on the application and purpose, such as spiral, hollow fiber, plate-and-frame, rotating flat membrane, and flat membrane stacking types. For example, a spiral separation membrane element generally consists of a supply-side channel material that guides the supply water to the separation membrane surface, a separation membrane, and a permeate-side channel material that guides the permeate water that has permeated through the separation membrane to a collection pipe. The supply-side channel material, separation membrane, and permeate-side channel material are spirally wound around the collection pipe.

[0022] Figure 1 shows an example of the flow in a water treatment plant. In Figure 1, the plant consists of a raw water storage tank 1 for storing the water to be treated (hereinafter referred to as raw water), a raw water supply pump 2 for supplying the raw water, a pre-treatment membrane filtration unit 3 for filtering the raw water, a pre-treatment membrane filtered water storage tank 4 for storing the filtered water from the pre-treatment membrane filtration unit 3, a separation membrane filtration unit 5, a booster pump 6 for supplying the filtered water from the pre-treatment membrane filtration unit 3 to the separation membrane filtration unit 5, and a booster pump 7 for further pressurizing the filtered water from the pre-treatment membrane filtration unit 3 in order to separate it into permeate and concentrated water in the separation membrane filtration unit 5.

[0023] Furthermore, the raw water storage tank 1 and the pre-treatment membrane filtration unit 3 are connected by raw water piping 8, the pre-treatment membrane filtration unit 3 and the pre-treatment membrane filtered water storage tank 4 are connected by pre-treatment membrane filtered water piping 9, and the pre-treatment membrane filtered water storage tank 4 and the separation membrane filtration unit 5 are connected by separation membrane filtration supply water piping 10. Raw water is treated in the pre-treatment membrane filtration unit 3, and the pre-treatment membrane filtered water is temporarily stored in the pre-treatment membrane filtered water storage tank 4. After being supplied to the booster pump 7 by the booster pump 6, it is pressurized by the booster pump 7 and then supplied to the separation membrane filtration unit 5, where it is separated into permeate water from which solutes such as salt have been removed and concentrated water from which solutes such as salt have been concentrated. These are then discharged through the separation membrane filtration permeate water piping 11 and the separation membrane filtration concentrated water piping 12, respectively.

[0024] The pretreatment membrane filtration unit 3 can use various pretreatment filters. Alternatively, the pretreatment membrane filtration unit 3 and the separation membrane filtration unit 5 may be units that include one separation membrane element, or units that include multiple separation membrane elements. Furthermore, in a water treatment plant, water-conducting members having a separation membrane inside may be installed in the plant's internal piping, such as the raw water piping 8, pretreatment membrane filtered water piping 9, separation membrane filtered supply water piping 10, separation membrane filtered permeate piping 11, and separation membrane filtered concentrated water piping 12.

[0025] In embodiments of the present invention, deposits can be collected not only from the pretreatment membrane filtration unit 3 and the separation membrane filtration unit 5, but also from members equipped with separation membranes, such as water-conducting members installed in plant piping.

[0026] An example of a water-conducting member is a water-conducting container formed by connecting one or more unit water-conducting members, each having a cylindrical shape and a connectable structure in which a separation membrane is installed perpendicular to the direction of water flow. In the case of a simple water-conducting container made of a soft material, the material attached to the separation membrane element can be collected by easily cutting it with scissors or the like and removing the separation membrane from the inside.

[0027] When a water treatment plant has multiple separation membrane elements, from the viewpoint of chemical selection accuracy, it is preferable to sample the material attached to the separation membrane element to be analyzed and / or measured from the separation membrane element with the largest amount of attachment.

[0028] Methods for selecting separation membrane elements with a large accumulation amount include physically collecting the deposits from the separation membrane elements or measuring the amount of deposits using various analytical and / or measurement methods. Due to the ease of operation, measuring the weight is preferred as a method for measuring the amount of deposits, and in that case, it is preferable to measure the weight in a dry state.

[0029] Another method involves selecting the separation membrane element that produces the largest differential pressure increase during operation. The differential pressure is the difference between the raw water pressure and the concentrated water pressure for each separation membrane element. This can be determined, for example, by the difference in readings from a pressure gauge installed on the raw water piping side and a pressure gauge installed on the concentrated water piping side, or by using differential pressure flow meters installed before and after the separation membrane element. Yet another method involves using the difference between the raw water pressure and the concentrated water pressure for multiple separation membrane elements as the differential pressure. However, from the standpoint of selection accuracy, the method using the differential pressure for multiple separation membrane elements is inferior to the method using the difference between the raw water pressure and the concentrated water pressure for a single separation membrane element.

[0030] Another example is using a separation membrane element in a separation membrane filtration unit in a water treatment plant where the permeate salt concentration or electrical conductivity has increased, or the water production rate has decreased.

[0031] Furthermore, due to the ease of selection, it is preferable to collect the deposits from the separation membrane element installed on the upstream or downstream side within the separation membrane filtration unit, and it is even more preferable to collect the deposits from the separation membrane element installed on the upstream or downstream side throughout the entire water treatment plant. By using the separation membrane element installed on the upstream side, it is possible to easily select the separation membrane element with a large amount of deposits. On the other hand, when deposits are observed in the water treatment plant due to the high solute concentration of the water being treated, collecting the deposits from the separation membrane element installed on the downstream side allows for the selection of chemical types to obtain more suitable analytical and / or measurement results. For example, this applies when the main components or chemical types are scale or scale inhibitors, as exemplified in the components and chemical types contained in the separation membrane element deposits described later.

[0032] Depending on the structure of the water treatment plant, there may be multiple separation membrane elements corresponding to the upstream and downstream ends. In such cases, it is preferable to select a separation membrane element with a large amount of attached material from among several candidates for analysis and / or measurement. One method of selection is to measure the weight of the separation membrane elements and select the one with the largest weight. At this time, it is preferable to measure after keeping the amount of water contained in the separation membrane element constant. One method of keeping the amount of water contained constant is to leave the separation membrane element removed from the water treatment plant for a certain period of time with the water flow direction perpendicular to the ground, drain the water from inside and outside the separation membrane element, and then measure its weight. The standing time is not particularly limited, but from the viewpoint of sufficiently draining the water from inside and outside the separation membrane element, a standing time of 30 minutes or more is preferable, and 1 hour or more is more preferable.

[0033] <Components contained in deposits collected from water treatment plants> The components contained in deposits collected from water treatment plants are substances that can constitute deposits, such as substances that are generally known to adhere and accumulate in water treatment plants. Examples include various inorganic scales and inorganic foulings. Scales are deposits formed by the precipitation of inorganic salts contained in raw water, and many inorganic salts with low solubility are known to be scales. Inorganic foulings refer to inorganic substances other than scales. In addition, there are bio-derived substances such as biofilms and slime (biofoulings), which are organic substances, as well as non-biological organic substances such as oils, lipids, proteins, sugars, and various surfactants (chemical foulings).

[0034] Examples of each component include, for example, sulfates and carbonates of calcium, barium, strontium, etc., calcium fluoride, calcium phosphate, chlorides of iron and aluminum, various other metal oxides, hydrated silica, silt, glucose and fructose, oligosaccharides, polysaccharides such as starch and cellulose, proteins, humic acid, fulvic acid, humic substances containing humic acid and fulvic acid, various microorganisms and biological substances, oils and fats, etc.

[0035] In this invention, the main components are those composed of elements, ions, and chemical structures that are present in large quantities and / or proportions in the deposits. Alternatively, they are the components listed in the table showing the corresponding indicators described below.

[0036] <Types of Chemicals> Examples of types of chemicals include general chemicals used to suppress and / or remove deposits collected from within a water treatment plant. Examples include chemicals added to raw water in the pretreatment process, which is a step prior to the separation membrane filtration unit 5 in Figure 1, as well as chemicals used to clean the separation membrane elements within the separation membrane filtration unit 5. In other words, examples include scale inhibitors, coagulants, auxiliary agents, disinfectants, and biological growth inhibitors used in the pretreatment process, acids and bases used in clean-in-place (CIP), other chemicals used to clean the separation membrane, and solutions containing multiple compounds found in these chemicals, as shown in the examples below.

[0037] A suitable example of a drug type in the embodiments of the present invention is a type based on compound composition. For example, if the types of compounds contained in a drug or the ratio of compounds differ, it is considered to be a different drug type. Another example of a drug type is one based on compound classification or application. From the viewpoint of selection accuracy, a drug type based on compound composition is preferable.

[0038] Examples of chemical types based on their application include classifications such as scale inhibitors, additives, flocculants, disinfectants, and biological growth inhibitors. Scale inhibitors are chemicals that prevent the formation of scale, which occurs when the amount and / or concentration of hardness components in water increases and salt precipitates. Examples of compounds include polyphosphates, polyacrylates, and phosphonates. Flocculants are chemicals that neutralize the charge of suspended particles in water and reduce electrostatic repulsion between particles. Examples include chemicals containing inorganic salts such as aluminum sulfate and ferric chloride. Additives are chemicals that promote the growth and separation of particulate matter formed after flocculation. Examples include chemicals containing inorganic salts such as aluminum sulfate, calcium oxide, calcium hydroxide, iron(II) sulfate, and iron(III) chloride, and organic polymers such as polyacrylamide. Examples of cleaning agents include acids, alkalis, surfactants, organic solvents, and chelating agents. Examples of compounds include those described later. Disinfectants and biological growth inhibitors have the effect of suppressing the formation of biofilms and slime, which are biologically derived contaminants, and killing or decomposing microorganisms. Examples of such compounds include halogenated compounds such as sodium hypochlorite and 2,2-dibromo-3-nitrilopropionamide, as well as ozone and isothiazolin. Furthermore, cleaning aids are preferred as auxiliary agents.

[0039] Examples of chemical types based on compound classification include acids, alkalis, chelating agents, surfactants, and organic solvents. Examples of acidic compounds include hydrochloric acid, sulfuric acid, citric acid, phosphoric acid, and oxalic acid, while examples of alkaliic compounds include sodium hydroxide and potassium hydroxide. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. Examples of compounds include sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene lauryl sulfate, polyethylene glycol, and polypropylene glycol. Chelating agents are chemicals that chemically stabilize metal ions by forming complexes with them. Examples of compounds include disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, sodium hexametaphosphate, nitrilotriacetic acid, and diethylenetriaminepentaacetic acid. Examples of organic solvent compounds include ethanol and 2-propanol.

[0040] Examples of drug types based on compound composition include those based on the compound composition described above, that is, the types of compounds contained and their proportions, amounts, and concentrations.

[0041] <Correspondence Index Showing the Recommendation Level of Drug Types> The correspondence index showing the recommendation level of drug types in this invention is an index that shows the recommendation level for each drug type for each component contained in the adhering material. This correspondence index is shown, for example, in a table format. As an example, Table 1 is shown, which lists the product name of the drug and several components. Examples of such correspondence tables include correspondence tables created and published by various companies that list multiple components and drug types, as well as newly created correspondence tables.

[0042]

[0043] Corresponding indicators that show the degree of recommendation, or as an example of the degree of recommendation listed in a correspondence table, include indicators that show the degree of recommendation for using each chemical, as listed in tables provided by each company. Other examples include indicators estimated and determined from the mechanism of action of compounds in each chemical on fouling components, which is publicly known knowledge, as well as indicators determined from chemical test results using separation membrane elements or separation membranes to which arbitrary deposits are attached. In particular, when creating new correspondence indicators, from the standpoint of reliability, the degree of recommendation to be described is preferably an indicator estimated and determined from the mechanism of action of each fouling component, or an indicator determined from chemical test results, and more preferably an indicator determined from chemical test results.

[0044] The known mechanisms of action of compounds in each chemical include, for example, dissolution, detachment, and decomposition, which are the main mechanisms for removing deposits from separation membranes. A higher index representing the driving force or speed of this mechanism indicates a greater recommendation. Examples of such indices include those representing the magnitude of electrostatic interactions, van der Waals interactions, hydrophobic interactions, and hydrogen bonds; those representing the solubility of the chemical and / or solvents with a high proportion in the chemical; and those representing the reaction rate in the reaction with the active ingredient in the chemical. Furthermore, a higher recommendation is given to chemical types that are known to be suitably used, even if the information is qualitative and less precise. For example, Table 2, which lists chemical types and contaminants based on their applications, is provided. The symbols in Table 2 represent the following: ◎ = Excellent: Highly effective (strongly recommended) 〇 = Good: Effective (recommended) △ = Fair: Low effectiveness or inhibits contaminant removal (not recommended)

[0045]

[0046] As an example of determining the degree of recommendation from the results of chemical tests, one method is to use the results of chemical tests using a separation membrane element used in a water treatment plant, or a separation membrane taken from a separation membrane element, and multiple types of chemicals. In this case, it is preferable that the amount of deposits on the separation membrane element or separation membrane used is the same, and it is also preferable to calculate the change before and after chemical contact, as described later, so it is preferable to evaluate the amount of deposits and / or the separation membrane performance before chemical contact. Furthermore, it is preferable to use a separation membrane element or separation membrane of a type that contains as few components in the deposits as possible. Another method is to use a model fouling separation membrane element or model fouling separation membrane, which is made by passing water containing fouling components through the separation membrane element or separation membrane, in the chemical test.

[0047] Methods for bringing a separation membrane element or separation membrane into contact with a chemical include immersing the separation membrane element or separation membrane in a solution containing the chemical and allowing it to stand or shake, or allowing the chemical or a solution containing the chemical to permeate the separation membrane element or separation membrane by pressurizing it, or flowing a solution parallel to the surface of the separation membrane to bring it into contact with the membrane.

[0048] The chemical test results may include, for example, the change in the amount of deposits before and after chemical contact, the change in the performance of the separation membrane element or separation membrane before and after chemical contact, the amount of deposits after chemical contact, and the performance of the separation membrane element or separation membrane after chemical contact. The change can be, for example, a difference, a ratio, or a rate of change, and from the viewpoint of recommendation and chemical selection accuracy, it is preferable to use a ratio or a rate of change. The separation membrane element or separation membrane performance is an index that indicates the removal, permeation, or separation selectivity of solute and / or solvent, as described below, for example. From the viewpoint of recommendation and chemical selection accuracy, it is preferable to use the change in solvent permeation rate or the change in solvent permeation coefficient.

[0049] In chemical tests, the separation membrane element or membrane used as a comparison before chemical contact can be appropriately selected depending on the purpose. For example, when focusing on the difference from the initial state of the separation membrane element, unused separation membrane elements or membranes, or separation membrane elements that are clearly free of deposits, should be used. "Clearly free of deposits" means, for example, that the analysis and / or measurement results described later are the same as those of an unused separation membrane element or membrane. "Unused" refers to a state where the product is stored in a sealed state without being opened during manufacturing, product shipment, or after product shipment. Preferably, the product is stored under appropriate conditions without being opened during or after product shipment. Furthermore, when focusing on changes due to chemical contact, the separation membrane element or membrane before chemical contact should be used.

[0050] When determining the recommendation level based on chemical test results, if the change before and after chemical contact is used, the recommendation level should be determined such that a larger change corresponds to a higher recommendation level. Alternatively, the recommendation level can be determined such that a smaller amount of deposits after chemical contact corresponds to a higher recommendation level. Furthermore, the recommendation level can be determined such that a higher separation membrane performance after chemical contact corresponds to a higher recommendation level. Here, separation membrane performance can be measured using solute removal rate, amount of solute permeated through the membrane (solute permeation amount), solute permeation coefficient, solvent permeation amount, solvent permeation coefficient, etc. The recommendation level should be determined such that the higher the solute separation selectivity and / or the higher the solvent permeation, the higher the separation membrane performance. In other words, the recommendation level should be determined such that the amount of solute (solute permeation amount) or solute permeation coefficient is small, or the solvent permeation amount or solvent permeation coefficient is large.

[0051] One method for calculating the performance of a separation membrane is to determine the amount of solvent or solute that passes through the membrane during a specified time period, based on the weight of the permeated liquid or the readings from instruments such as flow meters and conductivity meters. Another example is the solvent permeation coefficient or solute permeation coefficient calculated using the following method.

[0052] The permeate in a separation membrane consists of a solvent and a solute. The solvent permeates through the reverse osmosis membrane (hereinafter referred to as the RO membrane) due to the pressure difference, and the solute permeates through the RO membrane due to the concentration difference. As shown in equation (1) below, the solvent permeation flux Jv is expressed as the product of the solvent permeation coefficient Lp, which is specific to the RO membrane, and the effective pressure difference ΔPe. Also, as shown in equation (2) below, the solute permeation flux Js is expressed as the product of the solute permeation coefficient P, which is specific to the RO membrane, and the intermembrane concentration difference (Cm - Cp).

[0053]

[0054]

[0055] Here, Cm is the solute concentration on the film surface of the liquid being treated, Cp is the solute concentration in the treated liquid, Cs is the average solute concentration, π(C) is the osmotic pressure at concentration C, and σ is the reflectance.

[0056] Here, we assume the use of a membrane with a high desalination rate, where the reflectance σ is very close to 1, and the solvent permeation flux J ｖ and solute permeation flux J ｓ This is given by equations (3) and (4) below.

[0057]

[0058]

[0059] Furthermore, Cp is given by the following equation (5).

[0060]

[0061] When determining the solute concentration Cm on the film surface on the side of the liquid being treated, it is preferable to take into account the concentration polarization phenomenon (a phenomenon in which the salt concentration on the film surface on the side of the liquid being treated becomes higher than the salt concentration of the bulk liquid being treated due to the accumulation of solute on the film surface).

[0062] This concentration polarization phenomenon involves, for example, the movement of solute Jv·C associated with the solvent permeate flux and the diffusion D of the solute on the film surface on the treated liquid side. Ｃ dC / dx and the amount of solubilized mass (J) that permeated the membrane. ｖ ・C ｐ The following equation (6) is used, which represents the material balance using the three material balance equations.

[0063]

[0064] Here, D Ｃ is the diffusion coefficient of a solute. By integrating formula (6) representing the mass balance, the following formula (7) for concentration polarization is obtained.

[0065]

[0066] Here, k=D Ｃ / δ, where k represents the mass transfer coefficient and δ represents the thickness of the layer in which mass transfer occurs.

[0067] For example, the mass transfer coefficient k can be determined as follows.

[0068] The mass transfer correlation (Sh=a·Reb·Scc) is a formula representing the flow characteristics of a usage mode of an RO membrane (e.g., a spiral reverse osmosis membrane element), and expresses the relationship among the Sherwood number (Nusselt number) Sh, the Reynolds number Re, and the Schmidt number Sc. The Sherwood number Sh is a dimensionless quantity obtained by dividing the product of the mass transfer coefficient k and the flow channel thickness d of the layer where mass transfer occurs by the solute diffusion coefficient Dc as shown in formula (8), and represents the ease of solute movement.

[0069]

[0070] Here, the Reynolds number Re is obtained by dividing the product of the flow velocity u, density ρ, and representative length d of the liquid to be treated by the viscosity coefficient η as shown in formula (9), and represents the influence of the flow velocity of the liquid to be treated.

[0071]

[0072] Further, the Schmidt number Sc is obtained by dividing the viscosity coefficient η by the product of the density ρ and the solute diffusion coefficient Dc as shown in formula (10), and represents the influence of the physical properties of the liquid to be treated.

[0073]

[0074] The respective exponents b and c of the Reynolds number Re and the Schmidt number Sc in the mass transfer correlation are set to predetermined fixed values. For example, according to the Deissler equation, which is known as a mass transfer correlation for piping and the like, the exponents b and c are set to 0.875 and 0.25, respectively.

[0075] In this case, the mass transfer correlation equation is given by equation (11), and further from equation (8) and equation (11) below, we obtain equation (12).

[0076]

[0077]

[0078] Here, the unknown mass transfer correlation coefficient a in equation (12) can be determined by conducting experiments in which the flow velocity u of the liquid being treated is changed according to the application of the RO membrane.

[0079] It is known that the solvent permeability coefficient Lp and solute permeability coefficient P, which are inherent to RO membranes, change reversibly due to the influence of temperature, pressure, etc. Although the method for correcting the above reversible change is arbitrary, for example, the solvent permeability coefficient and solute permeability coefficient after the change can be denoted as Lp' and P', respectively, and the viscosity of the liquid being treated can be μ, and the viscosity of the liquid being treated at 25°C can be denoted as μ. ２５ Let Tf be the temperature of the liquid being treated, Pf be the pressure of the liquid being treated, and Ps be the standard operating pressure (e.g., the standard operating pressure listed in the product catalog). Let c be a constant specific to each type of film. １ , c ２ d １ d ２ Therefore, it is determined by the following equations (13) and (14).

[0080]

[0081]

[0082] In this way, the solvent permeation flux Jv and solute permeation flux Js can be calculated. That is, if the values ​​of the flow rate of the liquid to be treated Qf, the flow rate of the liquid being treated Qp, the membrane area A, the solute concentration of the liquid to be treated Cf, the solute concentration of the liquid being treated Cp, the pressure of the liquid to be treated Pf, the standard operating pressure Ps, and the temperature of the liquid to be treated Tf are known in advance, Jv and Js can be calculated from these values, and then Lp and P that satisfy Jv and Js can be determined.

[0083] Examples of corresponding indicators for the degree of recommendation of the present invention include quantitative indicators such as scores (numerical values), as well as qualitative indicators that indicate the degree of recommendation using symbols, etc. From the viewpoint of quantitativeity, it is preferable that the degree of recommendation be a quantitative indicator. If the degree of recommendation is a qualitative indicator, it is preferable that it be either an interval scale or an ordinal scale. An example of an interval scale is when the degree of recommendation is represented by the number of plus signs, as shown in Table 1. An example of an ordinal scale is when the degree of recommendation is indicated by symbols such as ◎, ○, △, ×, as shown in Table 2, etc., or when the degree of recommendation is represented by symbols or strings of characters such as letters of the alphabet.

[0084] In embodiments of the present invention, from the viewpoint of calculating the degree of recommendation and the accuracy of drug selection, when the corresponding index indicating the degree of recommendation is a qualitative index, it is preferable to set the score of the qualitative index indicating that use is not recommended to 0, the score of the qualitative index with the highest degree of recommendation to the number of levels of the qualitative index indicating the degree of recommendation, and the scores of other qualitative indexes indicating that they are recommended to be smaller than the score of the qualitative index with the highest degree of recommendation, and to set the numerical value to be larger the greater the degree of recommendation indicated by the original qualitative index, and to use this as the degree of recommendation for each component. In this way, by converting qualitative indexes to quantitative indexes and calculating the cumulative degree of recommendation, drug types can be selected more systematically.

[0085] For example, as shown in Table 1, if even one "+" indicates effectiveness against each stain component and therefore use is recommended, and the more "+"s there are, the higher the recommendation, the more it can be converted into a score as shown below and in Table 3: +++ = 3 points, ++ = 2 points, + = 1 point, no + = 0 points.

[0086]

[0087] Furthermore, if there is a qualitative indicator that indicates, for example, that use is prohibited or not recommended, the score of that qualitative indicator shall be a negative number whose absolute value is 1 greater than the product of the score of the qualitative indicator with the highest recommendation level and the number of drug types listed in the corresponding table. For example, as shown in Table 4, there are four drug types and four levels of qualitative indicators, including "not listed," and the recommendation level for each qualitative indicator is ◎ = particularly effective (strongly recommended), ○ = effective (recommended), × = use prohibited, then the scores can be converted as shown below and in Table 5. ◎ = Excellent: 4 (points), ○ = Good: 3 (points), Unsigned = Average: 0 (points), × = Poor: -13 (points).

[0088]

[0089]

[0090] As another example, the recommendation level is determined based on the number of levels of the sign indicating the recommendation level. That is, for example, as shown in Table 6, there are three levels of signs indicating the recommendation level, including unsigned, and if ○ is more recommended than △, it can be converted to a score as shown below and in Table 7. ○ = Good: 3 (points), △ = Fair: 2 (points), Unsigned = Average: 0 (points).

[0091]

[0092]

[0093] As described above, it is preferable to determine the score by considering the degree of recommendation that each symbol represents.

[0094] Furthermore, it is preferable that the correspondence table used includes the types of chemicals effective against the main components contained in the separation membrane element deposits. In addition, it is preferable to use a correspondence table that includes the components classified as being more abundant than organic or inorganic matter, and / or the types of chemicals that are highly recommended for those components, based on, for example, whether organic or inorganic matter is more abundant in the separation membrane element deposits. Whether organic or inorganic matter is more abundant can be determined by general analysis and / or measurement methods, but from the viewpoint of quantitative accuracy, it is preferable to determine this from the measurement results of the ash content of the separation membrane element deposits as described below.

[0095] The criteria for judgment are not particularly limited and can be set appropriately according to the raw water conditions and operating conditions of the target water treatment plant. For example, if the ash content is 40% or less, more preferably 25% or less, it is determined that there is a high amount of organic matter. Also, for example, if the ash content is 60% or more, more preferably 75% or more, it is determined that there is a high amount of inorganic matter.

[0096] <Analysis and / or Measurement Results> The elements, ions, and chemical structures contained in the deposits of the separation membrane element are, for example, the elements, ions, and chemical structures contained in each of the components mentioned above. An element is, for example, information on chemical species obtained by the various analysis and / or measurement methods described later. Depending on the analysis and / or measurement method used, at least one result can be obtained that distinguishes between chemical species such as neutral atoms and ions, or a result that does not distinguish between them, and either can be used in this embodiment. The analysis and / or measurement results representing the abundance of an element or ion are the analysis and / or measurement results relating to the amount, concentration, or ratio of each element and / or ion. In a water treatment plant, the form in which each element exists can easily change depending on the raw water composition, temperature, pH, etc. Therefore, it is preferable to use the total amount result that does not distinguish between chemical species (form of elements) such as neutral atoms and ions when expressing the abundance of an element or ion contained in each component substance.

[0097] In embodiments of the present invention, chemical structure refers to information on a part of a chemical structure, such as a chemical bond, as well as the chemical structure of a single substance (pure substance). The analytical and / or measurement results representing the abundance of the chemical structure contained in each component substance include, for example, analytical and / or measurement results relating to the amount, concentration, or ratio of each pure substance, as well as analytical and / or measurement results relating to the amount, concentration, or ratio of chemical bonds. In other words, examples include the ultraviolet-visible absorption intensity at any wavelength (nm), the fluorescence absorption intensity, the fragment ion peak intensity in mass spectrometry (MS), the absorption intensity corresponding to any chemical structure in various chromatographic methods, and analytical and / or measurement results relating to the amount, concentration, or ratio of an index corresponding to any chemical structure contained in biologically derived contaminants. Of these, it is preferable to use analytical and / or measurement results relating to the amount, concentration, or ratio of an index corresponding to any chemical structure specific to biological organisms such as chemical bonds, as described later.

[0098] In embodiments of the present invention, the analytical results and / or measurement results are preferably analytical results and / or measurement results that represent the abundance of at least one of the elements or ions listed in A to G below. This makes it possible to select a more appropriate type of chemical that is effective against inorganic substances when a large amount of inorganic substances are present in the deposits on the separation membrane element. A. Silicon B. Calcium C. Aluminum and / or iron D. At least one of copper, manganese, and iron E. At least one of cobalt, nickel, zirconium, fluorine, barium, and strontium F. Phosphorus G. At least one of sulfate ions, carbonate ions, and phosphate ions In particular, it is preferable to use at least one of A. silicon, B. calcium, D. copper, manganese, and iron, and G. sulfate ions, carbonate ions, and phosphate ions, and it is even more preferable to use at least one of A. silicon and B. calcium.

[0099] In embodiments of the present invention, analytical and / or measurement results relating to the amount or ratio of at least one of the following chemical structures are preferred as chemical structures contained in the separation membrane element deposits. In particular, analytical and / or measurement results that represent the abundance of at least one of the chemical structures described in A to F below are preferred. A to F below are preferred when there is a large amount of organic matter in the deposits, and G below allows for the selection of a more appropriately effective chemical type when there is a large amount of inorganic matter in the deposits. Each component containing each of the following chemical structures is exemplified in parentheses. A. Ether bond (sugars) B. Ester bond (fats and oils) C. Amide bond (proteins, bio-derived substances) D. Sulfonyl bond (surfactants) E. Aromatic carbon-carbon double bond (humic substances) F. Phosphorus-oxygen double bond (bio-derived substances) G. Silicon-oxygen bond (hydrated silica) In particular, A. Ether bond, C. Amide bond, E. Aromatic carbon-carbon double bond, F. Phosphorus-oxygen bond, G. It is preferable to use at least one silicon-oxygen bond, more preferably at least one of A. ether bond, C. amide bond, E. aromatic carbon-carbon double bond, and G. silicon-oxygen bond, and particularly preferable to use at least one of A. ether bond, C. amide bond, E. aromatic carbon-carbon double bond, and G. silicon-oxygen bond. Furthermore, it is preferable to use results normalized by analytical and / or measurement results concerning the abundance of chemical structures that originate from a standard substance or separation membrane and not from the deposits on the separation membrane element, as shown in Formula 15 below. Analytical and / or measurement results that originate from a standard substance or separation membrane and not from the deposits on the separation membrane element are, for example, results that differ from the analytical and / or measurement results of the deposits among the analytical and / or measurement results of a standard substance commonly used in each analytical and / or measurement method. Alternatively, if the deposits are not collected from the separation membrane but the entire separation membrane is used, the analytical and / or measurement results of the separation membrane, where it is obvious that there are no deposits as described above, are results that differ from the analytical and / or measurement results of the deposits.

[0100]

[0101] Here, Is(x) is the result of analysis and / or measurement regarding the abundance of the chemical structure derived from the separation membrane element deposits, and I(x) ｓ ) is the result of analysis and / or measurement regarding the abundance of chemical structures derived from the separation membrane element deposits in the deposits, and I(x ｒ ) is the result of analysis and / or measurement regarding the abundance of chemical structures in the deposits that originate from the standard substance or the separation membrane, and not from the deposits on the separation membrane element.

[0102] A preferred method for analyzing and / or measuring chemical structure is infrared spectroscopy, as described below. This method is preferred because it allows simultaneous analysis of chemical bonds in organic and inorganic substances, as well as indices that simulate the ratio of organic to inorganic substances, as described below. Examples of preferred infrared spectroscopy results include the integral values ​​of intensity and the maximum absorption intensity in the wavenumber ranges A to G below. The corresponding chemical structures are illustrated in parentheses. A. 1150–1050 cm⁻¹ －１ (Ether bond) B. 1750–1710 cm －１ (Ester bond) C. 1650–1610 cm －１ (Amide bond) D. 1135–1095 cm －１ (Sulfonyl bond) E. 800–760 cm －１　 (Aromatic carbon-carbon double bond) F. 1210-1180cm －１ (Phosphorus-oxygen double bond) G. 1110–830 cm －１ (Silicon-oxygen bond) In particular, when selecting a type of drug that is effective against biologically derived substances, C. 1650-1610 cm －１ ,E. 800-760cm －１ , F. 1210-1180cm －１ It is preferable to use at least one of the above, and if you are selecting a chemical that is effective against other organic or inorganic substances, then A. 1150-1050 cm －１ ,B. 1750-1710cm －１ ,G. 1110-830cm －１It is preferable to use at least one of the following. It is also preferable to use the result normalized by the integral value or maximum absorption intensity in an arbitrary wavenumber range (hereinafter referred to as the absorption band) that does not originate from the deposits. In other words, in the above formula 15, the analysis result and / or measurement result regarding the abundance of each chemical structure is the integral value of the intensity in the aforementioned absorption band or the maximum absorption intensity. For example, it is preferable to analyze the standard substance simultaneously with the deposits and normalize by the integral value of the absorption band intensity derived from the standard substance and not from the deposits, or by the maximum absorption intensity. Alternatively, it is preferable to normalize by the maximum absorption intensity or integral value of the intensity of the absorption band that originates from the separation membrane and not from the deposits on the separation membrane element. The absorption band that originates from the separation membrane and not from the deposits on the separation membrane element is, for example, the absorption band of the separation membrane that is clearly free of deposits in a wavenumber range where the intensity is 0 or greater when the intensity is subtracted from the intensity of the analysis result of the separation membrane with deposits from the intensity of the analysis result of the separation membrane with deposits for each wavenumber. Furthermore, for example, an absorption band where the intensity is 0 or less in the analysis results of attached substances, and greater than 0 in the analysis results of a separation membrane where it is obvious that there are no attached substances.

[0103] Another preferred example when each component is of biological origin, or when selecting a suitable type of chemical for a biological substance, is to use an arbitrary analytical and / or measurement result corresponding to the abundance of the substance as an analytical and / or measurement result representing the abundance of the chemical structure contained in the separation membrane element deposit. An arbitrary analytical and / or measurement result corresponding to the abundance of a biological substance is, for example, the result obtained by the ATP (adenosine-5'-triphosphate) quantitative method or the A3 method for quantifying the total amounts of ATP, ADP (adenosine diphosphate), and AMP (adenosine monophosphate), as described later.

[0104] In embodiments of the present invention, in estimating the relative abundance of at least one of the major components contained in the separation membrane element deposits, it is preferable to use at least one of the analysis results described in A to C below to calculate the ratio of inorganic matter to organic matter in the separation membrane element deposits: A. Ash content B. Ratio of the total amount of metal elements to the amount of carbon element C. Ratio of metallic bonds and metal-oxygen bonds to any functional group containing carbon element.

[0105] All of the above A to C can be treated as indicators showing the ratio of organic to inorganic matter. These are indicators in which the larger the result value, the higher the ratio of inorganic matter to organic matter, and are preferably used when both the estimated abundance of organic matter and the estimated abundance of inorganic matter are used in calculating the recommendation score. For example, if the analysis and / or measurement result of any of the above A to C is X １、 The concentration of elements in the deposits on the separation membrane element is X. ２ In this case, the relative abundance of inorganic matter is X １ ×X ２ It can be estimated using, and the abundance ratio of organic matter is (100 - X １ ) × X ２ It can be estimated using this method.

[0106] Ash content is an index expressed as a percentage of the weight of an analytical sample before combustion, measured after burning the sample at a high temperature. Measurement can be carried out, for example, by the method described in the examples below.

[0107] Furthermore, examples of metal elements and chemical bonds for B. the ratio of the total amount of metal elements to the amount of carbon elements, and C. the ratio of metallic bonds and metal-oxygen bonds to any functional group containing carbon elements include the various metal elements mentioned above, as well as chemical bonds containing metal elements and oxygen elements. In other words, examples of metal-oxygen bonds include Si-O, Fe-O, Al-O, Ti-O, Zn-O, etc. Furthermore, as C. any functional group containing carbon elements, in addition to the chemical bonds in A. to C. or E. mentioned above, carbon-carbon single bonds, (aliphatic) carbon-carbon double bonds, and carbon-hydrogen bonds are listed as preferred examples, and C. amide bonds, E. aromatic carbon-carbon double bonds, carbon-carbon single bonds, (aliphatic) carbon-carbon double bonds, and carbon-hydrogen bonds are listed as particularly preferred examples.

[0108] In this embodiment, the analytical and / or measurement results representing the abundance of at least one element, ion, or chemical structure in the separation membrane element deposits are results relating to at least one of the amount, concentration, or content ratio of the element, ion, or chemical structure in the separation membrane element deposits. Examples include results obtained by directly calculating the separation membrane element deposits or the separation membrane containing the deposits, or by using multiple results. Furthermore, if at least one analytical and / or measurement result of an element, ion, or chemical structure is not the amount, concentration, or ratio in the separation membrane element deposits per unit area of ​​the separation membrane element or per dry weight of the separation membrane deposits, it is preferable to convert it using, for example, multiple analytical and / or measurement results before using it. Note that "per unit area of ​​the separation membrane element" refers to per unit area of ​​the separation membrane provided by the separation membrane element.

[0109] In embodiments of the present invention, the amount of at least one element, ion, and chemical structure contained in the separation membrane element deposit is preferably the amount of at least one element, ion, and chemical structure contained in the separation membrane element deposit per unit area of ​​the separation membrane element, the amount of substance per dry weight of the separation membrane element deposit, or the content ratio in the separation membrane element deposit. More preferably, it is the amount of substance of the element and / or ion contained in the separation membrane element deposit per dry weight of the separation membrane element deposit. This makes it possible to estimate the abundance ratio of each component in the separation membrane element deposit.

[0110] Furthermore, for example, in the case of elements and / or ions, it is preferable to use analytical and / or measurement results relating to the weight of presence (g or mg), amount of substance (mol), concentration (g / L or mg / L), or their ratios, and in the case of chemical bonds, it is preferable to use the ratio of the amount of presence for any particular chemical bond (functional group). In particular, it is preferable to use results relating to the ratio in the deposits on the separation membrane element, or the weight per dry weight of the deposit (mg / g-dry) or the amount of substance per dry weight of the deposit (mol / g-dry), and it is even more preferable to use the amount of substance per dry weight of the deposit (mol / g-dry).

[0111] As a further example, values ​​such as the membrane area of ​​the separation membrane element from which the deposits were collected, the weight of the deposits on the separation membrane used for analysis and / or measurement, and the amount of deposits per unit area of ​​the separation membrane element are used to estimate the relative abundance of each component, converted to values ​​per unit area of ​​the separation membrane element or per dry weight of the deposits on the separation membrane. It is also preferable to use results that take into account the number of years of operation of the water treatment plant. That is, for example, the amount of substance per unit area of ​​the separation membrane element (mol / m²) ２ ) and the amount of substance per year of operation in a water treatment plant (mol / year), and the value obtained by dividing by both (mol / m ２／(Years) is preferred. These values ​​include, for example, elements, ions, various analysis and / or measurement results as described below, as well as the dry weight of the deposit used in the analysis (mg-dry) and the area of ​​the separation membrane used in the analysis and / or measurement (m²). ２ ), or the area of ​​the separation membrane from which the attached material was collected (m²) ２ It is calculated using, for example, ), etc.

[0112] For example, if the analysis and / or measurement result is the weight of element E per dry weight of deposits W(E) (mg / g-dry), then the dry weight of deposits Wl (g / m²) per membrane area of ​​the separation membrane element ２ By calculating the product of this, the weight of element E per unit area Wm(E) (mg / m²) can be determined. ２ ) is calculated. Furthermore, as shown in Equation 16, the amount of substance Wm(E) (mol / m) per unit area of ​​the separation membrane element is calculated using the atomic weight Ar(E) of element E. ２ It is preferable to calculate ( ).

[0113]

[0114] Here, Ar(E) is the atomic weight of element E.

[0115] In this invention, the analysis results and / or measurement results include not only primary data directly obtained through analysis and / or measurement, but also results obtained through any data processing or analysis commonly used in analysis and / or measurement methods. These results are generally in the form of quantified information and can be obtained using various commercially available analysis or measurement devices, as well as measurement and / or analysis programs attached to such devices.

[0116] Furthermore, if there are chemicals already being used in the water treatment plant, it is preferable to consider their effects. Specifically, it is preferable to consider the effects of the chemicals already being used by performing calculations based on the type and / or concentration of the chemicals already being used on at least one of the analysis results and / or measurement results, as well as the estimated results of the abundance ratio of each component.

[0117] For example, one approach is to add the estimated reduction or concentration of each component, which is presumed to be reduced in deposits, raw water, and separation membrane filtration feedwater by the use of the agent, or the estimated amount or concentration when the agent is not used, to the relative abundance of each component used in calculating the cumulative recommendation level.

[0118] Another example involves adding the estimated reduction amount, estimated reduction amount or concentration, or estimated amount or concentration when the agent is not used, of each element, cation, and / or anion that constitutes each component, whose concentration is estimated to be reduced in deposits, raw water, and separation membrane filtration feedwater by the use of the agent, to the analytical results and / or measurement results of each element, cation, and / or anion when the agent is not used, when estimating the abundance ratio of each component.

[0119] The choice of which computational process to use can be arbitrarily selected based on the available information and the precision of the selection.

[0120] <Estimation of the relative abundance of each component> Each component refers to the various substances that may be contained in the deposits collected from the water treatment plant, as described above. If the main components contained in the deposits collected from the water treatment plant are the components described below, it is preferable to use the analytical results and / or measurement results described in each section.

[0121] If each component is an oxide, analytical and / or measurement results regarding the abundance of metal elements contained in the oxide are used. In estimating the abundance ratio of each component, if each component contains an oxide, it is preferable to estimate the abundance ratio of the oxide based on analytical and / or measurement results representing the abundance of metal elements contained in the oxide in the deposition of the separation membrane element. This improves the accuracy of the recommendation calculation.

[0122] For example, if each component is calcium oxide or silica (silicon dioxide), the analysis and / or measurement results regarding the abundance of calcium and silicon elements are used. Similarly, if each component is iron oxide or aluminum oxide, the analysis and / or measurement results regarding the abundance of iron and aluminum elements are used.

[0123] If each of the above components includes an inorganic salt, it is preferable to estimate the relative abundance of the inorganic salt based on analytical results and / or measurement results representing the amount of at least one of the cations, anions, and elements constituting the inorganic salt in the deposition on the separation membrane element. This improves the accuracy of the recommendation calculation.

[0124] Furthermore, for example, if each component is an inorganic salt, the analytical results and / or measurement results concerning the cation or anion constituting the inorganic salt, or the element constituting said cation or anion, are used. Hereafter, cations and anions will be collectively referred to as ions.

[0125] At this time, it is preferable to consider the abundance and ratio of metal elements and / or ions in the components. For example, if component i is an oxide, and the analysis and / or measurement results regarding the abundance of metal elements and / or ions I are a ｉ Therefore, b is an index that represents the abundance or ratio of metal element I in component i. ｉ In that case, the ratio of component i contained in the deposit is X as shown in Equation 17. ｉ We estimate b. ｉ Examples include weight ratios and mole ratios.

[0126]

[0127] For example, if each component is calcium carbonate or calcium sulfate, the analysis and / or measurement results of calcium ions, carbonate ions, sulfate ions, or the elements that constitute these ions, namely calcium, carbon, oxygen, or sulfur, are used. Of these, since carbon and oxygen are likely to be present in other components as well, it is preferable to use the analysis and / or measurement results regarding the abundance of carbonate ions, sulfate ions, calcium, and sulfur. Also, for example, in the case of iron chloride or aluminum chloride, the analysis and / or measurement results regarding the abundance of iron(II) ions, iron(III) ions, aluminum ions, chloride ions, or the elements that constitute these ions, namely iron, aluminum, or chlorine, are used.

[0128] As another example, it is preferable to use the analysis and / or measurement results of elements and / or ions that do not constitute other components. For example, if an anion constituting an inorganic salt A is an anion constituting another component substance, and a cation constituting inorganic salt A is not a component cation of the other component substance, it is preferable to use the cation constituting inorganic salt A, or an element that is a component of the cation but is not a component of the other component substance.

[0129] For example, first, the analysis and / or measurement results of the element and / or ion to be used to estimate the abundance ratio of any one component are determined. Next, for each of the remaining components, it is preferable to determine the analysis and / or measurement results of the element and / or ion to be used for each component in a way that does not overlap with the components already determined. For example, if the components are calcium oxide, calcium sulfate, and calcium carbonate, the abundance ratio of calcium oxide, which is an oxide, is estimated using the analysis and / or measurement results regarding the abundance of the element calcium. For example, the amount of substance (mol) of the element calcium per dry weight of the material attached to the separation membrane element is taken as the abundance ratio of calcium oxide. On the other hand, the abundance ratio of calcium sulfate is estimated using the analysis and / or measurement results of elements other than calcium. That is, for example, using the analysis and / or measurement results regarding the abundance of sulfate ions or sulfur elements, which are elements and / or ions that do not overlap with calcium oxide, for example, the amount of substance (mol) of the element sulfur per dry weight of the material attached to the separation membrane element is taken as the abundance ratio of calcium sulfate. Furthermore, the abundance ratio of calcium carbonate is determined using the analysis and / or measurement results regarding the abundance of elements other than those mentioned above, namely, carbonate ions or carbon elements, and the amount of carbon element per unit dry weight (mol) is taken as the abundance ratio of calcium carbonate.

[0130] Another preferred example is a method that uses the ions and / or elements constituting each component to estimate the relative abundance of each element based on the abundance of the corresponding ions. For example, the relative abundance of component i X as shown in Equation 18. ｉ We estimate this.

[0131]

[0132] Here, [Cat. (i)] represents the analytical and / or measurement results indicating the abundance of the cation and / or the element constituting the cation in the deposit, and [Ani. (i)] represents the analytical and / or measurement results indicating the abundance of the anion and / or the element constituting the anion in the deposit. Furthermore, Σ[Ani. (i)] is the sum of the analytical and / or measurement results indicating the abundance of the cations and / or the elements constituting all components from component 1 to component n in the deposit, where i is an integer from 1 to n. Here, components 1 to n are the components listed in the correspondence table indicating the recommendation level of the chemical types mentioned above.

[0133] A more preferred example is to consider the abundance of the cation and / or the element constituting the cation, and the anion and / or the element constituting the anion, in component i, as shown in formula 19. For example, a physical quantity c representing the abundance of the cation and / or the element constituting the cation contained in component i in component i. ｉ and a physical quantity a representing the abundance of the anion contained in component i and / or the element constituting said anion in component i. ｉ Let X be the relative abundance of component i. ｉ To estimate this, for example, using the aforementioned analysis results and / or measurement results [Cat. (i)] and [Ani. (i)] and the amount of substance (mol) per unit area of ​​separation membrane or amount of deposit, if 1 mol of component i contains 2 mol of the cation and / or elements constituting the cation and 1 mol of the anion and / or elements constituting the anion, then in formula 19, c ｉ = 2, a ｉLet = 1. As another example, if the analytical results and / or measurement results [Cat. (i)] and [Ani. (i)] are expressed as weight (g) per unit area of ​​separation membrane or per unit amount of deposit, and component i is aluminum chloride, and 1 g contains 0.20 g of aluminum, which is the cation and / or the element constituting the cation, and 0.80 g of chlorine, which is the anion and / or the element constituting the anion, then in formula 19, c ｉ = 0.20, a ｉ Let's assume it equals 0.80.

[0134]

[0135] Another example is the abundance ratio X of component i, as shown in Equation 20 above. ｉ One method for estimating this is given. Here, Σ[Cat. (i)] is the analytical result and / or measurement result representing the abundance of anions and / or elements constituting all components in the deposit, and is the sum of [Ani. (i)] from component 1 to component n. Also, [Cat. (i)] and [Ani. (i)] are the aforementioned analytical result and / or measurement result. Another preferred example is the aforementioned c as shown in equation 21. ｉ and a ｉ Using this method, the abundance ratio X of component i is calculated by considering the amount of the anion and / or the element constituting the anion in component i. ｉ An example of estimating this is given.

[0136]

[0137]

[0138] The choice of which of the above methods to use depends on the analysis and / or measurement results of the attached material being used. For example, one could use the results obtained from the various analysis and / or measurement methods described later that have the highest analysis and / or accuracy. Another example is to use the analysis and / or measurement results obtained using an analysis and / or measurement method that yields many of the results at once, from among all the analysis and / or measurement results used to estimate each component. Alternatively, one could choose according to the available analysis and / or measurement methods.

[0139] For example, if component i is calcium sulfate, the cation constituting component i and / or the element constituting said cation is a calcium ion or a calcium element, and analysis results and / or measurement results regarding the amount of calcium element present in the deposition of the separation membrane element are used. Also, the anion constituting component i and / or the element constituting said anion is a sulfate ion, a sulfur element, or an oxygen element, and analysis results and / or measurement results regarding the amount of sulfur element are used.

[0140] Furthermore, for example, if Table 1 is a correspondence table showing the recommended degree of different drug types, then component 1 is CaCO1 ３ (Calcium carbonate), component 2 is BaSO ４ (Barium sulfate) and SrSO ４ (Strontium sulfate), component 3 is SiO ２ (H ２ Let O)x be the result of analysis and / or measurement of the abundance of calcium element and carbonate ions in the deposits that constitute component 1 [Ca], [CO]. ３ ２－ ] and analytical and / or measurement results regarding the abundance of barium, strontium, and sulfate ions in the deposits that constitute component 2 [Ba], [Sr], [SO] ４ ２－ Using the analysis results and / or measurement results [Si] regarding the abundance of silicon element constituting component 3, the abundance ratio X of each component was determined. １ ~X ３ This is estimated using equations 22 to 24.

[0141]

[0142]

[0143]

[0144] Furthermore, for example, the abundance ratio X of each component is calculated using the analysis and / or measurement results [Ca] [C] regarding the abundance of calcium and carbon elements that constitute component 1, the analysis and / or measurement results [Ba] [Sr] [S] regarding the abundance of barium, strontium, and sulfur elements that constitute component 2, and the analysis and / or measurement results regarding the abundance of silicon element that constitutes component 3. １ ~X ３ This is estimated using equations 25, 26, and 24.

[0145]

[0146]

[0147] If each component is an organic substance, for example, the relative abundance is estimated using analytical results and / or measurement results regarding the amount of chemical structure contained in the component.

[0148] For example, if component 1 is a protein and component 2 is a sugar, then the chemical structure in component 1 is an amide bond and the chemical structure in component 2 is an ether bond, and the relative abundance X of each component is given by formula 27 or formula 28. １ and X ２ This is estimated. Here, [amide] represents the amount (ratio) of amide bonds in the deposit, and [ether] represents the amount (ratio) of ether bonds, which is the result of analysis and / or measurement. For example, it is the result of dividing the integral value of the intensity in the absorption band derived from each bond by the integral value of the intensity across all measured absorption bands, as obtained by the infrared absorption spectroscopy method described above.

[0149]

[0150]

[0151] Another example involves using analytical and / or measurement results that represent the amount of a bond originating from a component other than the component whose abundance is being estimated, within the attached material. For example, assuming component 1 is an oil or fat, and the chemical structure contained in component 1 is an ester bond, the elemental composition analysis result [Si] representing the amount of silicon element and / or ions, and the maximum absorption intensity I (Si-O) of the absorption band originating from the silicon-oxygen bond and the maximum absorption intensity I (ester) of the absorption band originating from the ester bond are used to estimate the abundance X of component 1 as shown in Equation 29. １ We estimate this.

[0152]

[0153] As another example, as mentioned above, analytical and / or measurement results relating to the quantity of an index corresponding to any chemical structure contained in a biologically derived substance can be used. For example, analytical and / or measurement results representing the amount of microorganisms or bacterial count estimated from the ATP amount mentioned above can be used. In this case, it is preferable to use analytical and / or measurement results representing the amount of microorganisms or bacterial count per unit weight of attached material. For example, it is preferable to calculate the amount of microorganisms or bacterial count per unit area by dividing the index by the weight of attached material per unit area of ​​membrane, and to estimate the relative abundance of the biologically derived substance component.

[0154] <Calculation of Cumulative Recommendation and Selection Method of Chemical Types> In this invention, the cumulative recommendation of multiple chemical types for the separation membrane element deposits is calculated based on the estimated abundance ratio of each component contained in the separation membrane element deposits and a corresponding index indicating the recommendation level of multiple chemical types used in water treatment plants for each of the aforementioned components. Furthermore, at least one or more chemical types are selected based on a comparison of the magnitudes of the calculated cumulative recommendation levels.

[0155] In embodiments of the present invention, it is preferable to use a score obtained by accumulating the product of the estimated abundance ratio of each component contained in the separation membrane element deposits and the recommendation score for each component when calculating the cumulative recommendation score. This makes it possible to quantitatively and systematically compare the cumulative recommendation scores for each type of chemical.

[0156] The estimated ratio of component i contained in the separation membrane element deposits is Xｉ , wherein when the recommendation degree of chemical D for component i, which is a corresponding indicator, is S ｄｉ , the cumulative recommendation degree TS of chemical D ｄｉ can be calculated using the product of S ｄｉ and X ｉ . For example, when there are 5 types of components contained in the deposits on a separation membrane element, and the estimated existence ratio of each component is X １ to X ５ , and a correspondence table that includes 3 types of chemicals D to F, in which corresponding indicators indicating recommendation degrees are described, is used, the cumulative recommendation degree TS of chemical D ｄ can be calculated using the following Formula 30.

[0157]

[0158] The cumulative recommendation degree TS of chemical E ｅ and the cumulative recommendation degree TS of chemical F ｆ are also calculated in the same manner using the estimated existence ratio X of component i ｉ and the recommendation degree S of chemical E for each component i ｅｉ or the recommendation degree S of chemical F ｆｉ , and a recommended chemical type is selected by comparing the magnitude of TS ｄ , TS ｅ and TS ｆ . Examples of recommended chemical types include the most recommended chemical type, that is, the chemical type having the largest cumulative recommendation degree, as well as any number of chemical types with high recommendation degrees, that is, large cumulative recommendation degrees.

[0159] <Analysis and / or Measurement Method> In the present invention, various general methods that can acquire analysis results and / or measurement results representing the abundance of at least any one of elements, ions, and chemical structures contained in deposits on a separation membrane element in the deposits on the separation membrane element can be used, and there is no particular limitation.

[0160] The material adhering to the separation membrane element may be used in either a wet or dry state. Methods for drying include natural drying and heat drying using an oven or constant temperature bath. For example, the collected material adhering to the separation membrane element can be dried by heating it to 20°C to 120°C and drying it until the weight change is less than ±0.1g. Alternatively, drying can be performed under low pressure conditions using a diagram pump or a vacuum dryer attached to an oil rotary vacuum pump. When used in a wet state, it is preferable to perform a moisture content adjustment treatment beforehand. Methods for adjusting the moisture content include adjusting the relative humidity at a constant temperature. For example, the saturated salt method described in JIS B 7920:2000 can be used.

[0161] When preparing the material adhering to the separation membrane element to be either dry or wet with controlled moisture content, it is preferable to perform this as a pretreatment at least one day before or immediately before the analysis or measurement.

[0162] When analyzing and / or measuring separation membrane element deposits together with the separation membrane, it is generally preferable to analyze and / or measure the separation functional layer side of the separation membrane, as the separation membrane element deposits tend to concentrate and accumulate on the separation functional layer side. From the viewpoint of detection depth, it is preferable to irradiate the separation functional layer side of the separation membrane with the analytical light source, for example, when using various light sources such as infrared light, electron beams, and X-rays as described later. By using an analytical method that allows control of the detection depth in this way, it is possible to obtain analytical results that contain as little information as possible about the separation membrane.

[0163] Methods for analyzing and / or measuring elements and / or ions include atomic absorption spectrophotometry, inductively coupled plasma emission spectrometry (ICP), total internal reflection X-ray fluorescence emission spectrometry (TXRF), energy-dispersive X-ray spectroscopy (EDX), electron probe microanalyzer (EPMA), Auger electron spectroscopy (AES), energy-dispersive spectroscopy (EDS), photoelectron spectroscopy using X-rays (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS) and Rutherford backscattering analysis (RBS) using ion beams. Of these, when analyzing and / or measuring deposits on a separation membrane together with the separation membrane, it is preferable to use a scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDX), electron probe microanalyzer (EPMA), Auger electron spectroscopy (AES), or XPS. When using collected deposits on the separation membrane element, it is preferable to use energy-dispersive X-ray spectroscopy (EDX) or inductively coupled plasma emission spectrometry (ICP), and it is preferable to use inductively coupled plasma emission spectrometry (ICP). Another possible method involves dissolving or burning the deposits on the separation membrane element with an acid solution, and then analyzing them by gas chromatography (GC) or liquid chromatography (LC). For example, methods described in JIS K 0050, JIS K 0132, JIS K 0152, JIS K 0154, JIS K 0102, etc., can be used.

[0164] Methods for analyzing chemical structure include infrared absorption spectroscopy (IR), ultraviolet-visible spectroscopy, nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), gas chromatography (GC), liquid chromatography (LC), and thin-layer chromatography (TLC). Of these, when analyzing deposits on a separation membrane together with the separation membrane, infrared absorption spectroscopy (IR) is preferred, and using total internal reflection infrared spectroscopy (ATR) is even more preferred. When using collected deposits on the separation membrane element, infrared absorption spectroscopy (IR), mass spectrometry (MS), nuclear magnetic resonance spectroscopy (NMR), etc., are preferred. Among infrared absorption spectroscopy methods, the tablet method using powders such as potassium bromide or potassium chloride, or mass spectrometry, is preferred. For example, methods described in JIS K 0117, JIS K 0124, JIS K 0114, JIS K 0123, JIS K 0127, JIS K 0138, JIS K 0115, JIS K 0133, JIS K 0102, etc., can be used.

[0165] The above methods can also be used to analyze indicators that simulate the ratio of organic to inorganic matter. Other methods include wet and dry methods for measuring ash content, such as the method described in JIS K 7250.

[0166] Other examples of analytical and / or measurement methods include quantitative methods for elements, ions, and chemical structures using various color reactions, such as the phenanthrone spectrophotometric method for iron quantification, the BCA method using bicinchoninic acid, the Bradford method using Coomassie brilliant blue dye, the copper-Folin (Lowry) method, and methods using the Pierce 660nm Protein Assay reagent. Other examples include ATP (adenosine-5'-triphosphate) quantification methods, the A3 method for quantifying the total amounts of ATP, ADP (adenosine diphosphate), and AMP (adenosine monophosphate), polyacrylamide electrophoresis (SDS-PAGE), and methods using fluorescent dyes and fluorescence microscopes. For example, methods described in JIS K 0102, etc., can be used.

[0167] Various general methods can be used to measure the amount of deposits on the separation membrane element. For example, one weighing method involves drying the deposits recovered from the separation membrane together with the container, weighing them using an electronic balance, and then subtracting the weight of the container (tare). Another example is a method that can obtain analytical results that correlate with the total amount of deposits on the separation membrane element. In addition to the various analytical and / or measurement results mentioned above, examples include using measurement results that correlate with the total amount of contamination, such as chromaticity, surface reflectance, and transmittance (transparency), and methods described in JIS Z 8722, for example, can be used. Of the above, it is particularly preferable to use the dry weight of the deposits.

[0168] <Example of Use> When determining whether or not to use chemicals that have not been used conventionally in a water treatment plant, the chemical selection method of the present invention can be used to predict in advance the troubles that may occur when new chemicals are used. Furthermore, if operational troubles occur in a water treatment plant due to deposits on the separation membrane element, the chemical selection method of the present invention can be used to systematically select chemicals that are more effective in improving the operational troubles.

[0169] Furthermore, by regularly performing the chemical selection method of the present invention at a frequency of once a day to once a week, it becomes easier to identify when the risk of separation membrane contamination suddenly increases, or when separation membrane troubles or operational troubles occur and where they occur, allowing for prompt implementation of corrective measures.

[0170] <Diagnostic Program, Evaluation Device, Recording Medium> Another embodiment of the present invention is a program for selecting chemical types to be used in a water treatment plant, comprising: a data input means for inputting data relating to analysis results and / or measurement results of deposits on a separation membrane element into the computer; a data recording means for recording the data and a corresponding index indicating the degree of recommendation for each component that may be contained in the deposits on the separation membrane element of a plurality of chemical types used in a water treatment plant in the computer; a means for estimating the abundance ratio of each component contained in the deposits on the separation membrane element from the analysis results and / or measurement results; a means for calculating the cumulative degree of recommendation for the deposits on the separation membrane element of the plurality of chemical types based on the estimated abundance ratio of each component and the corresponding index; and a means for selecting and outputting at least one or more chemical types based on a comparison of the magnitudes of the cumulative degrees of recommendation.

[0171] As shown in the schematic diagram of Figure 2 as an example of an embodiment of the present invention, the estimation means 23 estimates the abundance ratio of each component from the analysis results and / or measurement results of the deposits on the separation membrane element input to the data input means 22. The calculation means 25 calculates the cumulative recommendation level for each drug type from the estimation results and the corresponding index indicating the recommendation level for each component of a plurality of drug types recorded in the data recording means 24, and the output means 26 outputs at least one or more recommended drug types.

[0172] The output means 26 may output the cumulative recommendation score for each drug type, and the drug type with the highest cumulative recommendation score. In this case, the cumulative recommendation score for each drug type may be output as data in which the drug type and cumulative recommendation score are listed in a table format, or as a list of numerical and / or string data that allows the correspondence between the drug type and the cumulative recommendation score to be determined.

[0173] The data recording means 24 functions not only as a means for pre-recording data related to the corresponding indicator, but also as a means for inputting and recording new data related to the corresponding indicator into the computer 20 when using the program 21, etc.

[0174] In data relating to a corresponding indicator newly recorded in a computer, if the recommendation level is a qualitative indicator, it is preferable that the data recording means has a conversion means for converting the qualitative indicator into a quantitative indicator such as a score. This makes it possible to select drug types more systematically, even when the corresponding indicator showing the recommendation level is a qualitative indicator.

[0175] The data regarding the correspondence indicators can be of any type or format, as long as it shows the degree of recommendation for each drug type for each component.

[0176] The output means 26 outputs data relating to at least the recommended types of drugs. This data relating to the types of drugs includes the compound name, drug product name, and drug composition. From the standpoint of convenience, it is preferable that the cumulative recommendation score for each type of drug is also output as part of the output data, and it is even more preferable that the estimated abundance ratio of each component is also output.

[0177] This embodiment can be recorded on a computer memory, hard disk, or other recording device, and the recording method is not particularly limited. Another embodiment of the present invention includes a recording medium storing the aforementioned program, a computer-readable recording medium, and a device equipped with the aforementioned program.

[0178] The present invention will be described below using examples, but the present invention is not limited in any way by these examples.

[0179] (Analysis Method) The separation membrane element was disassembled, and deposits were collected from a specified area of ​​the separation membrane surface using a silicone scraper. The deposits were placed in a stainless steel dish and air-dried for 30 minutes. Then, they were dried at 120°C for 2 hours in a natural convection constant temperature test chamber MDN-19GA (Isuzu Manufacturing Co., Ltd.), and the dry weight of the deposits on the separation membrane element was measured.

[0180] The aforementioned deposits were further weighed into a platinum crucible, dried at 105°C for 4 hours, and then heated in an electric furnace at 550°C for 12 hours. The ash content was determined by gravimetric method. Furthermore, the ashed samples were melted in a mixed flux of sodium carbonate and boric acid, and solutions prepared by dissolving them in dilute nitric acid, as well as solutions prepared by dissolving them in nitric acid and hydrofluoric acid, were subjected to qualitative and semi-quantitative analysis using ICP emission spectroscopy with an Optima 4300DV (PerkinElmer, Inc.) to obtain elemental composition analysis results. Specifically, the abundance of each element per 1 kg of deposit (mg / kg-dry) was obtained for any given element.

[0181] <Example 1> In order to select a scale inhibitor to be used in the RO pretreatment of water treatment plant A, separation membrane element A, which had been used in water treatment plant A for approximately 1.4 years, was dismantled and deposits were collected. The dry weight of the deposits was measured, and further, the area of ​​the membrane from which the deposits were collected (m²) was measured. ２ The dry weight of deposits per unit area of ​​the separation membrane element was calculated from the above, and the result was 4.98 g / m². ２ The results of the elemental composition analysis are shown in Table 8.

[0182]

[0183] The index shown in Table 1 was used as a correspondence index to indicate the degree of recommendation for each component of multiple types of chemicals used in water treatment plants. Each symbol in Table 1 represents the following: +++: Excellent (highly recommended), ++: Good (strongly recommended), +: Fair (recommended), No +: Average (not recommended).

[0184] For each sign in Table 1, a score was calculated according to the number of +++ symbols. In other words, the sign with the lowest recommendation level, without a +, was assigned a score of 0, and the following scores were calculated to create Table 3: +++ = 3 (points), ++ = 2 (points), + = 1 (point), + none = 0 (points).

[0185] Based on the aforementioned elemental composition analysis results and the dry weight of deposits per unit area of ​​the separation membrane element, the relative abundance X of each component listed in Tables 1 and 3 is calculated. １ ~X ３The results of the estimation are as shown in Table 9. Further, from the recommendation degrees S １ to S ３ for each chemical type described in Table 3, the cumulative recommendation degree 100×Σ(Xi×Si) for each chemical type was calculated. For example, S １ to S ３ for Chemical A are as follows based on each recommendation degree described in "Chemical A" in Table 3, and the cumulative recommendation degree 100×Σ(Xi×Si) was 0.090 (points).

[0186]

[0187] S １ = 2 (points), S ２ = 2 (points), S ３ = 3 (points).

[0188] Similarly, as a result of calculating the cumulative recommendation degree for each chemical type, Chemical B was 0.086 (points) and Chemical C was 0.014 (points). As a result of comparing the magnitude of the cumulative recommendation degrees, Chemical A had the largest value, so Chemical A was selected as the scale inhibitor used in the RO pretreatment of water treatment plant A.

[0189] <Example 2> A rapid increase in differential pressure was observed in a separation membrane filtration unit of water treatment plant B, so it was decided to select a cleaning chemical. The separation membrane element B that had been used in water treatment plant B for one year was disassembled, and deposits were collected. The deposits were dried and weighed, and the dry weight of deposits per separation membrane element area was calculated from the membrane area (m ２ ) where the deposits were collected, and the result was 3.95 g / m ２ . The elemental composition analysis results are as shown in Table 10.

[0190]

[0191] The indicators described in Table 5 were used as correspondence indicators indicating recommendation degrees for each of the aforementioned components of a plurality of chemical types used in water treatment plants. As a result of estimating the abundance ratios X １ to X ５ of each component described in Table 5 using the aforementioned elemental composition analysis results and the dry weight of deposits per separation membrane element area, the results were as shown in Table 11. Further, from the recommendation degrees S １ to S ５From this, the cumulative recommendation score of each drug type was calculated as 100 × Σ(Xi × Si). For example, the S of drug A-1 １ ~S ５ The following is the result of the recommendation levels listed in Table 5, "Drug A-1," and the cumulative recommendation level 100 × Σ(Xi × Si) was -0.099 (points). １ =0 (point), S ２ =0 (point), S ３ =-13 (points), S ４ =3 (points), S ５ =0 (points).

[0192]

[0193] Similarly, the cumulative recommendation score for each chemical was calculated, and the results were 0.009 (points) for chemical A-2, 16.48 (points) for chemical B-1, and 16.59 (points) for chemical B-2. Comparing the cumulative recommendation scores of each chemical, chemical B-2 had the highest score, so chemical B-2 was selected and applied as the cleaning agent to be used in water treatment plant B, resulting in a decrease in differential pressure.

[0194] <Example 3> A rapid increase in differential pressure was observed in the separation membrane filtration unit of water treatment plant C. Therefore, the unit was cleaned with acidic and alkaline detergents, but the cleaning effect was unsatisfactory, and the differential pressure did not decrease significantly. To select a cleaning aid, separation membrane element C, which had been used in water treatment plant C for one year, was disassembled, and deposits were collected. The deposits were dried and weighed, and the area of ​​the membrane (m²) from which the deposits were collected was further measured. ２ The dry weight of deposits per unit area of ​​the separation membrane element was calculated from the above and found to be 0.22 g / m². ２ The results of the elemental composition analysis are shown in Table 12.

[0195]

[0196] Table 13 was used as a corresponding index to indicate the degree of recommendation for each component of multiple chemical types used in a water treatment plant. Similar to Example 2, the relative abundance of each component was estimated from the elemental composition analysis results and the dry weight of deposits per unit area of ​​the separation membrane element. Furthermore, the cumulative recommendation score of each chemical type, 100 × Σ(Xi × Si), was calculated from the recommendation scores listed in Table 13.

[0197]

[0198] The cumulative recommendation score for each chemical was calculated as follows: Chemical C-1: 2.691 points, Chemical C-2: 1.731 points, Chemical C-3: 0.713 points, Chemical C-4: 0.662 points, and Chemical C-5: 0.414 points. Comparing the cumulative recommendation scores of each chemical, Chemical C-1 had the highest score, followed by Chemical C-2. Therefore, when Chemical C-1 was mixed with a basic (alkaline) detergent and Chemical C-2 with an acidic detergent as cleaning additives used in water treatment plant C, the differential pressure decreased.

[0199] 1: Raw water storage tank 2: Raw water supply pump 3: Pretreatment membrane filtration unit 4: Pretreatment membrane filtered water storage tank 5: Separation membrane filtration unit 6: Booster pump 7: Pressure boosting pump 8: Raw water piping 9: Pretreatment membrane filtered water piping 10: Separation membrane filtered water supply piping 11: Separation membrane filtered permeate piping 12: Separation membrane filtered concentrated water piping 20: Computer 21: Program 22: Data input means 23: Means for estimating abundance ratio 24: Data recording means 25: Means for calculating cumulative recommendation score 26: Means for selecting and outputting chemical types

Claims

1. A method for selecting types of chemicals to be used in a water treatment plant, comprising: estimating the abundance ratio of at least one element, ion, and chemical structure contained in the deposits collected from within the water treatment plant from analytical results and / or measurement results representing the abundance of the deposits; calculating a cumulative recommendation level for the deposits of the multiple chemicals to be used in the water treatment plant based on the estimated abundance ratio of each component and a corresponding index indicating the recommendation level for each of the multiple chemicals to be used in the water treatment plant; and selecting at least one type of chemical based on a comparison of the magnitudes of the cumulative recommendation levels.

2. The method for selecting drug types according to claim 1, wherein in calculating the cumulative recommendation score, a score is obtained by accumulating the product of the estimated abundance ratio of each component and the recommendation score for each component.

3. A method for selecting chemical types according to claim 1 or 2, wherein, in estimating the abundance ratio of each component, if an oxide is included in each component, the abundance ratio of the oxide is estimated based on analytical results and / or measurement results representing the amount of metal elements contained in the oxide in the deposit.

4. A method for selecting a type of chemical according to claim 1 or 2, wherein, in estimating the abundance ratio of each component, if an inorganic salt is included among the components, the abundance ratio of the inorganic salt is estimated based on analytical results and / or measurement results representing the abundance of at least one of the cations, anions, and elements constituting the inorganic salt in the deposit.

5. The method for selecting the type of chemical according to claim 1 or 2, wherein the analysis result and / or measurement result represents the amount of at least one element or ion listed in A to G below present in the deposit: A. Silicon B. Calcium C. Aluminum and / or iron D. Copper, manganese, iron E. At least one of cobalt, nickel, zirconium, fluorine, barium, and strontium F. Phosphorus G. At least one of sulfate ions, carbonate ions, and phosphate ions 6. A method for selecting a type of chemical according to claim 1 or 2, wherein the analysis result and / or measurement result represents the amount of at least one of the chemical structures A to F described below in the attached substance: A. Ether bond B. Ester bond C. Amide bond D. Sulfonyl bond E. Aromatic carbon-carbon double bond F. Phosphorus-oxygen bond 7. A method for selecting a type of chemical according to claim 1 or 2, wherein the analysis result and / or measurement result is any of the following: the amount of at least one element, ion, and chemical structure contained in the deposit, per unit area of ​​the deposit region of the deposit, the amount of substance per unit dry weight of the deposit, or the content ratio in the deposit.

8. The method for selecting the type of chemical according to claim 7, wherein the analysis result and / or measurement result is the amount of substance of the element and / or ion contained in the deposit per unit dry weight of the deposit.

9. A method for selecting chemical types according to claim 1 or 2, wherein, in estimating the relative abundance of each component, at least one of the analysis results described in A to C below is used to calculate the ratio of inorganic matter to organic matter in the deposit: A. Ash content B. Ratio of the total amount of metal elements to the amount of carbon element C. Ratio of metallic bonds and metal-oxygen bonds to any functional group containing carbon element 10. A method for selecting chemical types according to claim 1 or 2, wherein the influence of chemicals already used in the water treatment plant is taken into consideration by performing calculation processing based on the type and / or concentration of chemicals already used in the water treatment plant on at least one of the analysis results and / or measurement results and the estimated results of the abundance ratio of each component.

11. The method for selecting chemical types according to claim 1 or 2, wherein the corresponding index is determined from the results of chemical tests using multiple types of chemicals on a separation membrane element or separation membrane to which any deposit is attached, and is a corresponding index indicating the degree of recommendation of the multiple types of chemicals for each component that may be contained in the deposit.

12. A method for selecting drug types according to claim 1 or 2, wherein the recommendation level in the corresponding index is a qualitative index, the score of the qualitative index indicating that use is not recommended is set to 0, the score of the qualitative index with the highest recommendation level is set to the number of levels of the qualitative index indicating the recommendation level, the scores of other qualitative index indicating that it is recommended are set to be smaller than the score of the qualitative index with the highest recommendation level, and to be larger the greater the recommendation level indicated by the original qualitative index, and are used as the recommendation level for each component.

13. The method for selecting the type of chemical according to claim 1 or 2, wherein the deposit is a deposit collected from any one of the following: plant piping, pretreatment filter, separation membrane element, and water passage member.

14. The method for selecting the type of chemical according to claim 13, wherein the deposit is collected from a separation membrane element installed on the upstream or downstream side of a water treatment plant.

15. The method for selecting the type of chemical according to claim 14, wherein the deposit is a deposit collected from the surface of the separation membrane.

16. The method for selecting the type of chemical according to claim 1 or 2, wherein the chemical used in the water treatment plant is at least one of a scale inhibitor, a cleaning agent, a cleaning aid, and a disinfectant.

17. A program for selecting types of chemicals to be used in a water treatment plant, wherein the computer functions as: a data input means for inputting data relating to the analysis results and / or measurement results of deposits collected from within the water treatment plant into the computer; a data recording means for recording the data and a corresponding index indicating the degree of recommendation for each component that may be contained in the deposits for a plurality of types of chemicals used in the water treatment plant; a means for estimating the abundance ratio of each component contained in the deposits from the analysis results and / or measurement results; a means for calculating the cumulative recommendation degree for the plurality of chemicals for the deposits based on the estimated abundance ratio of each component and the corresponding index; and a means for selecting and outputting at least one type of chemical based on a comparison of the magnitudes of the cumulative recommendation degrees.

18. The program according to claim 17, further comprising means for performing calculation processing based on the type and / or concentration of chemicals already used in the water treatment plant on at least one of the analysis results and / or measurement results and the estimated ratio of each component, thereby taking into account the influence of the chemicals already used.

19. A computer-readable recording medium having the program described in claim 16 or 17 recorded on it.

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