Membrane treatment method and biofouling suppression method

Abstract

The present invention provides a technique for inhibiting endotoxin production in a water system, or a technique for satisfying both biofouling inhibition and endotoxin production inhibition. The present invention provides a membrane treatment method or a biofouling suppression method in which a bound halogen compound is present in a water system in which gram-negative bacteria are present. The present invention provides a method for inhibiting endotoxin production in a water system, wherein a bound halogen compound is made to be present in the water system.

Description

Technical Field

[0001] The present invention relates to a membrane treatment method, a biological fouling inhibition method, an endotoxin generation inhibition method in water, an endotoxin concentration reduction method in water, and the like. Background Art

[0002] If the endotoxin in the bacterial cell, which is called endotoxin, enters the human body, it will cause a decrease in activities such as fever or blood sugar. Therefore, it is desirable to suppress the endotoxin concentration as low as possible in the treated water after water system treatment, especially in the treated water of a water treatment system for medical use (for example, pure water, dialysate, etc.).

[0003] Generally, membrane treatment is performed to suppress the endotoxin concentration. However, depending on the condition of the membrane or the operating conditions, sometimes the endotoxin cannot be suppressed below the target concentration, and sometimes additional treatment such as ultraviolet (UV) treatment is required after membrane treatment (for example, Patent Document 1, Non-Patent Document 2).

[0004] In addition, in order to suppress biofouling of a water treatment device or system such as membrane treatment, a slime inhibitor or the like is usually used. However, it is also known that, for example, when a slime inhibitor such as chlorine (sodium hypochlorite) exerts a biofouling inhibitory effect on a water system, endotoxin is generated or produced in the water system, and thus endotoxin exists in the water system (for example, Non-Patent Document 1).

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: WO2020 / 004272

[0008] Patent Document 2: WO2011 / 125762

[0009] Non-Patent Documents

[0010] Non-Patent Document 1: Huang Huang et al., "Effect of chlorination on endotoxin activities in secondary sewage effluent and typical Gram-negative bacteria", "Water Research", (45(2011)4751 - 4757)(Huang Huang et al., "Effect of chlorination on endotoxin activities in secondary sewage effluent and typical Gram-negative bacteria", WATER RESEARCH 45(2011)4751 - 4757.)

[0011] Non-Patent Document 2: Kenichi Ono et al., "Effect of Membrane Pressure in Reverse Osmosis Apparatus on Concentration of Endotoxin in Treated Water", Journal of Dialysis 35(5): 281-286, 2002

[0012] Non-Patent Document 3: J.S. Vrouwenvelder et al., "Biofouling of Spiral Wound Membrane Systems" (published by International Water Association (IWA) in 2011) (J.S. Vrouwenvelder et al., "Biofouling of Spiral Wound Membrane Systems" IWA Publishing (2011).)

[0013] Non-Patent Document 4: Wataru Suda et al., "16S Analysis and Metagenomic Analysis of Bacterial Flora in the Environment Using Next-Generation Sequencer", Journal of the Japanese Society for Microbial Ecology 27(2): 63-39, 2012 Summary of the Invention

[0014] Problems to be Solved by the Invention

[0015] Therefore, the main object of the present invention is to provide a technique for suppressing the generation of endotoxin in a water system, or a technique that satisfies both biofouling suppression and endotoxin generation suppression.

[0016] Technical Means for Solving the Problems

[0017] The present inventors made diligent studies, and as a result, by making a bound halogen compound (hereinafter, also referred to as "the bound halogen compound") generated by using at least a halogen-based compound and an amino group-containing compound (hereinafter, also referred to as "amino compound") as a stabilizing compound present in a water system, a technique for suppressing the generation of endotoxin in a water system and a technique that satisfies both biofouling suppression and endotoxin generation suppression were newly discovered. The present invention is as described below.

[0018] The present invention provides a membrane treatment method or a biofouling suppression method, in which a bound halogen compound generated by using at least a halogen-based compound and an amino compound as a stabilizing compound is present in a water system in which Gram-negative bacteria are present.

[0019] In addition, the present invention provides an endotoxin generation suppression method in a water system, in which a bound halogen compound generated by using at least a halogen-based compound and an amino compound as a stabilizing compound is present in the water system.

[0020] Effects of the Invention

[0021] According to the present invention, a technique for suppressing the generation of endotoxin in a water system, or a technique that satisfies both biological fouling suppression and endotoxin generation suppression, can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram showing an example of the water system of the present invention.

[0023] Figure 2 is a schematic diagram of a water treatment device including MFS used in the water passing test of the [Embodiment] of this case. The present embodiment is not limited thereto.

[0024] Figure 3 is a diagram showing the presence ratio of each bacterium in the bacterial flora in the biofilm attached to the RO membrane surface after the water passing test of the [Embodiment] of this case. From the bottom up are Cupriavidus, Pseudomonas, Ralstonia, Acidovorax, Azotobacter, other gram-negative bacteria, gram-positive bacteria, and Unknown.

[0025] Figure 4 is a schematic diagram of a water treatment device including MFS used in the water passing test of the [Embodiment] of this case. The present embodiment is not limited thereto. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, the modes for implementing the present invention will be described. In addition, the embodiments described below are examples showing representative embodiments of the present invention, and do not limit and interpret the scope of the present invention thereby. In addition, the upper limit value (hereinafter) and the lower limit value (above) in the numerical values can be arbitrarily combined as needed. In the present embodiment, for example, "(in the case of performing)" such as "(in the case of adjusting)" can be regarded as "process" or "step", and "step" can be regarded as "(in the case of performing)" or "process", and "process" can be regarded as "(in the case of performing)" or "step". In the present embodiment, "process", "component", "mechanism" can be regarded as a system, device, part, or method, and vice versa, "device" can be regarded as a system, component, mechanism, or part, and vice versa. In addition, "part" can be regarded as a part or device included in an institution, device, component, or system, and vice versa.

[0027] 1. Membrane treatment method and biological fouling suppression method of the present invention

[0028] ​​​​In the description of the method of the present embodiment, it is appropriate to omit the description of each structure or each method such as the water system, membrane treatment, biofouling inhibition, endotoxin generation inhibition, chemicals, etc. that are repeated with those described later in "2." etc. The description of "2." etc. also applies to the present embodiment and can be appropriately adopted.

[0029] Conventionally, as a slime inhibitor for a water treatment system, inorganic bound chlorine such as chloramine or 2,2-dibromo-3-nitrilopropionamide (DBNPA), an organic slime inhibitor of the isothiazoline type, etc. have been generally used. However, if these are used for a long time, sometimes drug-resistant bacteria proliferate. As the drug-resistant bacteria, Gram-negative bacteria are mostly dominant, and endotoxins derived therefrom are discharged.

[0030] In addition, conventionally, in a water system in which Gram-negative bacteria are present, when a biofouling inhibitor is added to the water system, there has been a problem that the amount of endotoxin in the water system increases. For example, in the case of 5-chloro-2-methyl-4-isothiazoline-3-one (Cl-MIT), which is a kind of organic slime inhibitor, alone, in the case of chloramine (mono-, di-, tri-), which is a kind of bound halogen compound commonly used for disinfection of tap water or swimming pools, etc., and in the case of sodium hypochlorite, which is a kind of chlorine-based oxidant with strong bactericidal power as described in Non-Patent Document 1, although Gram-negative bacteria in the water system can be inhibited and biofouling can be inhibited, an effect of inhibiting endotoxin generation has not been obtained.

[0031] Therefore, the present inventors focused on the relationship between endotoxin concentration inhibition and biofouling inhibition in a water system, the occupancy ratio of Gram-negative bacteria, which are the cause of endotoxin generation and the cause of concentration increase, in the bacterial flora, and explored and used methods of compounds capable of inhibiting biofouling.

[0032] The inventors of the present invention have made intensive studies and as a result, it has been found that by allowing a bound halogen compound formed by using at least a halogen-based compound and an amino compound as a stabilizing compound or a bound halogen compound having a molecular weight of 60 or more (hereinafter referred to as the "bound halogen compound") to be present in a water system, it is possible to achieve endotoxin production inhibition, and endotoxin production inhibition and biofouling inhibition. Moreover, an excellent advantage of the bound halogen compound is that even when the presence of Gram-negative bacteria in the water system is high, endotoxin production inhibition, and endotoxin production inhibition and biofouling inhibition can be achieved by using it. That is, by allowing the bound halogen compound to be present in the water system, it is also possible to lower the concentration of endotoxin in the water system. In addition, the inventors of the present invention have found that if the bound halogen compound is allowed to be present in the water system, the dominant presence ratio of Gram-negative bacteria in the water system can be inhibited, and thus there is an advantage that endotoxin production can be easily inhibited, and the state of the flora in the water system and the endotoxin concentration in the water system can be controlled.

[0033] In addition, the inventors of the present invention have made intensive studies and as a result, it has been found that if a bound halogen compound of a stabilizing compound having an amino group such as sulfamic acid and a halogen-based compound is added as a biofouling inhibitor or an endotoxin production inhibitor to a water system containing Gram-negative bacteria, it shows an effect in inhibiting the growth of a biofilm, and the presence ratio (proportion) of Gram-negative bacteria in the biofilm can be inhibited, and in addition, the production amount or generation amount of endotoxin can be inhibited.

[0034] Furthermore, the inventors of the present invention have found that when a bound halogen of a stabilizing amino compound such as sulfamic acid and a halogen-based compound or a chemical agent containing the bound halogen is added to a water system (preferably a water treatment system) at a concentration capable of inhibiting the growth of a biofilm as a biofilm inhibitor, the endotoxin production amount can be inhibited to 50% or less as compared with general biofouling inhibition methods such as chloramine, DBNPA, and isothiazoline.

[0035] Therefore, the inventors of the present invention have made intensive studies and as a result, it has been found that by allowing a bound halogen compound formed by using at least a halogen-based compound and a stabilizing amino compound to be present in a water system, it is possible to achieve either endotoxin production inhibition or both concentration inhibition and biofouling inhibition in the water system. Furthermore, the inventors of the present invention have also found that even in a water system dominated by Gram-negative bacteria, by allowing the bound halogen compound to be present in the water system, there is an excellent advantage that endotoxin production can be inhibited and biofouling can also be inhibited.

[0036] Furthermore, the inventors of the present invention also found that by using, as an index, one or more of the type of Gram-negative bacteria selected, the number of Gram-negative bacteria, and the ratio of the presence of Gram-negative bacteria in the flora, it is possible to determine the presence or use (time point, period, amount, total halogen concentration, etc.) of the bound halogen compound in the water system. In addition, Pseudomonas spp. and / or Cupriavidus spp. can be used as an index.

[0037] Furthermore, the inventors of the present invention found that although no endotoxin production inhibitory effect was obtained when the organic slime inhibitor was used alone, when the organic slime inhibitor was contained or used in the water system, by intermittently (for example, adding for 1 hour to 0.25 hours in a day) containing or using the bound halogen compound in the water system, the endotoxin production inhibitory effect was close to that in the case of continuous addition of the bound halogen compound alone, and the endotoxin production amount was about half or less of that in the case of using the organic slime inhibitor alone.

[0038] Furthermore, the inventors of the present invention also found that by using the bound halogen compound in the water system, the endotoxin concentration can be suppressed low before membrane treatment, so that the subsequent treatment can be further simplified, the load can be reduced, or the endotoxin concentration in the final process can be suppressed, and treated water with a reduced endotoxin concentration can be produced.

[0039] Therefore, the present embodiment can provide a membrane treatment method or a biofouling inhibition method in which a bound halogen compound formed by at least using a halogen-based compound and an amino compound as a stabilizing compound or a bound halogen compound having a molecular weight of 60 or more is present in the water system. At this time, the bound halogen compound can also be used to inhibit the production of endotoxin in the water system. In addition, the present embodiment can also provide a membrane treatment method accompanied by biofouling inhibition or biofilm formation inhibition.

[0040] The present embodiment can provide an endotoxin production inhibition method in which the bound halogen compound is present in the water system. In addition, the present embodiment can be an endotoxin production inhibition method or an endotoxin concentration reduction method, and can also be a method for producing or generating treated water with inhibited endotoxin production or reduced endotoxin concentration.

[0041] The combined halogen compound is preferably a compound formed by using at least a halogen-based compound and a stabilizing compound (preferably an amino compound). It can be a compound formed by adding a one-component agent or a multi-component agent to a water system, or a compound formed by adding a halogen-based compound and / or a stabilizing compound to the water system at the same time or at different times. Alternatively, it can also be a compound formed by using a halogen-based compound or a stabilizing compound present in the water system and then adding a halogen-based compound and / or a stabilizing compound. In addition, the water system to be used is not particularly limited, and it can also be applied to a system containing a halogen-based compound or an amino compound derived from raw water or a process, or it can be a water system into which either one is introduced.

[0042] Furthermore, in this embodiment, since both biofouling inhibition and endotoxin generation inhibition can be achieved, a method for inhibiting biofouling and endotoxin generation in a water system, a method for inhibiting the growth of Gram-negative bacteria and biofouling in a water system can be provided. In addition, it can also be a method for producing or generating treated water with inhibited endotoxin generation or reduced endotoxin concentration by membrane treatment.

[0043] This embodiment can provide a membrane treatment method or a biofouling inhibition method, in which an agent containing a combined halogen compound formed by using at least a halogen-based compound and an amino compound as a stabilizing compound or a combined halogen compound with a molecular weight of 60 or more is added to a water system.

[0044] In addition, this embodiment can also provide a membrane treatment method or a biofouling inhibition method, in which a combined halogen compound formed by using at least a halogen-based compound and / or a stabilizing compound is present in the water system.

[0045] This embodiment can also provide a membrane treatment method or a biofouling inhibition method, in which in a water system containing a halogen-based compound or an amino compound derived from raw water or a process, a combined halogen compound is generated by using a halogen-based compound and / or a stabilizing compound, and the combined halogen compound is present in the water system.

[0046] This embodiment preferably adjusts the total halogen concentration in the water system to a specified concentration (preferably 0.01 mg / L to 100 mg / L) and / or adjusts the water system to a specified total halogen concentration (preferably 0.01 mg / L to 100 mg / L).

[0047] This embodiment preferably uses a combined halogen compound in the water system or the agent, which is formed by adjusting the molar ratio of the stabilizing compound to the halogen-based compound (stabilizing compound / halogen-based compound) to 1.0 or more.

[0048] This embodiment preferably uses, as an index, one or more of the species selected from Gram-negative bacteria, the number of Gram-negative bacteria, and the ratio of Gram-negative bacteria in the bacterial flora to determine the use (time point of use, period of use, amount present, total halogen concentration, etc.) of the bound halogen compound.

[0049] The water system in this embodiment is preferably a water system in which Gram-negative bacteria are present, and is preferably a water treatment system, more preferably a membrane treatment system. The water system is not particularly limited, and examples thereof include: a water treatment water system; a circulating water system such as a cooling tower; a process water system, a water use system, or a drainage recovery system in pulp manufacturing, etc. The water system is preferably a water treatment system, and the water treatment system is more preferably a membrane treatment system or a water system or a water treatment system including a membrane treatment device. The water system is preferably a water system including a membrane treatment system including a membrane treatment device.

[0050] In this embodiment, by containing or using the bound halogen compound in the water system, a technique for better suppressing endotoxin generation in the water system can be provided, and in addition, a technique for better satisfying both endotoxin generation suppression and biological fouling suppression in the water system can be provided. Furthermore, in this embodiment, in the water system, more appropriate use efficiency or use cost reduction effects, more appropriate endotoxin generation suppression effects, biological fouling suppression effects, etc. can be obtained.

[0051] 1-1. Bound halogen compound

[0052] The combined halogen compound used in this embodiment is preferably a compound formed by using at least a halogen-based compound and a stabilizing compound (preferably an amino compound), or a compound having a molecular weight of 60 or more. The combined halogen compound is preferably a compound formed by using at least a halogen-based compound and a stabilizing compound (preferably a stabilized amino compound). In addition, examples of the combined halogen compound include one or more selected from combined chlorine compounds (also called combined chlorine agents, stabilized chlorine agents), stabilized bromides (also called combined bromine agents, stabilized bromine agents), etc., but are not limited to these. Among them, as a preferred combined halogen compound, a chlorine-based aminosulfonic acid compound and / or a bromine-based aminosulfonic acid compound are preferred. The chlorine-based aminosulfonic acid compound can be formed, for example, from a chlorine-based oxide (such as sodium hypochlorite, etc.) and an aminosulfonic acid compound (such as aminosulfonic acid) under the condition that the pH value is 11 or more. The bromine-based aminosulfonic acid compound can be formed, for example, from a bromine-based oxide (such as liquid bromine, etc.) and an aminosulfonic acid compound (such as aminosulfonic acid) under the condition that the pH value is 11 or more. In addition, the so-called molecular weight can be obtained by the sum of the atomic weights contained in the molecule. In addition, the molecular weight of the combined halogen compound is not particularly limited, and the preferred lower limit is preferably 60 or more in molecular weight, and the preferred upper limit is not particularly limited and can be 1,000 or less or 500 or less. The combined halogen compound or the agent containing the compound can use commercially available products or can use the combined halogen compound obtained by a known manufacturing method.

[0053] The combined halogen compound or the agent containing the compound is preferably a combined halogen compound formed by using at least a halogen-based compound and a stabilizing compound. The combined halogen compound can also be a combined halogen compound (such as a stabilized bromide, etc.) formed by using a halogen-based compound and a stabilized amino compound and further using a stabilized bromide as described in <Stabilized Bromide> below. In addition, the halogen-based compound or the stabilizing compound existing in the water system can be utilized or used, and the halogen-based compound and / or the stabilizing compound can be further added or mixed in the water system to form a combined halogen compound.

[0054] In addition, it is preferred to further use a halogen-based compound and / or a stabilizing compound to form the combined halogen compound in a water system or water containing a halogen-based compound or an amino compound derived from raw water or a process. The raw water derived from can be raw water or treated water introduced as raw water, and the process-derived can be process water after being treated by each treatment process, and more preferably a water system derived from raw water or a process containing a halogen-based compound or a stabilizing compound (preferably an amino compound).

[0055] In addition, the halogen-based compounds and stabilization compounds used in this embodiment can be used directly. Alternatively, they can also be used as agents respectively. The halogen-based compounds and stabilization compounds used in this embodiment can be used as halogen-based oxidants and stabilizers respectively. Alternatively, they can also be used as agents containing halogen-based compounds or halogen-based oxidants, and agents containing stabilization compounds or stabilizers respectively.

[0056] 1-1-1. Halogen-based compounds

[0057] Examples of the halogen-based compounds used in this embodiment include one or more selected from chlorine-based oxides, bromine-based oxides, etc. Chlorine-based oxides and bromine-based oxides can be chlorine-based oxidants and bromine-based oxidants respectively. Regarding bromine-based oxides, the description of <stabilized bromide> can be preferably adopted.

[0058] The chlorine-based oxides are not particularly limited. For example, they include chlorine gas, chlorine dioxide, hypochlorous acid or its salts, chlorous acid or its salts, chloric acid or its salts, perchloric acid or its salts, trichloroisocyanuric acid chloride or its salts, etc. One or more selected from these can be used, and hypochlorite is preferably used among them.

[0059] Examples of hypochlorites include alkali metal hypochlorites such as sodium hypochlorite and potassium hypochlorite; alkaline earth metal hypochlorites such as calcium hypochlorite and barium hypochlorite, etc. One or more selected from these can be used.

[0060] Examples of chlorites include alkali metal chlorites such as sodium chlorite and potassium chlorite; alkaline earth metal chlorites such as barium chlorite; other metal chlorites such as nickel chlorite, etc. One or more selected from these can be used.

[0061] Examples of chlorates include ammonium chlorate; alkali metal chlorates such as sodium chlorate and potassium chlorate; alkaline earth metal chlorates such as calcium chlorate and barium chlorate, etc. One or more selected from these can be used.

[0062] Examples of perchlorates include sodium perchlorate, potassium perchlorate, etc. One or more selected from these can be used.

[0063] Examples of trichloroisocyanuric acid chlorides include sodium trichloroisocyanurate, etc. One or more selected from these can be used.

[0064] The bromine-based oxides are not particularly limited. For example, they include bromine (liquid bromine), bromine chloride, bromic acid, bromates, and hypobromous acid, etc. One or more selected from these can be used.

[0065] 1-1-2. Stabilization compounds

[0066] The stabilizing compound used in this embodiment is not particularly limited, and preferably a compound that can react with a halogen-based compound to form a bound halogen compound, which is also called a stabilizer. As the preferred stabilizing compound, for example, compounds having an amino group such as an aminosulfonic acid compound (hereinafter, also called "stabilizing amino compound") can be cited, and one or more than two of these can be used.

[0067] In addition, in this embodiment, a monovalent functional group (-NHH, -NHR, -NRR') formed by removing hydrogen from a primary amine or a secondary amine is called an "amino group", which is distinguished from ammonia (or its salt). Among the compounds having an amino group used in this embodiment (hereinafter, also called "amino compounds"), there are one or more amino groups, and they can also be heterocyclic.

[0068] <Amino compounds>

[0069] As the amino compounds used in this embodiment, for example, organic amino compounds such as primary amines (R-NH2) such as urea, acid amides (RCONH2) such as amino acids, sulfonamides (RSO2NH2 (R is a hydrocarbon residue, etc.)), and heterocyclic compounds having an amino group such as hydantoin can be cited; inorganic amino compounds such as hydroxylamine (NH2OH) and hydrazine (NH2NH2). As sulfonamides, for example, aminosulfonic acid, 4-aminosulfonylbenzoic acid, carbamic acid, methanesulfonamide, etc. can be cited; as amino acids, glycine, etc. can be cited. In addition, hydantoin is structurally equivalent to the cyclic condensate of glycolic acid and urea.

[0070] In addition, the amino compound is preferably a sulfur-containing amino compound such as an aminosulfonic acid compound or an aminosulfonylbenzoic acid compound (preferably having a molecular weight of 20 or more, and / or preferably having a molecular weight of 400 or 300, 200 or less). One or more than two of these amino compounds can be used.

[0071] <Bound halogen compound: chloramine sulfonic acid>

[0072] The aminosulfonic acid compound constituting the chloramine sulfonic acid compound is preferably a compound represented by R 1 R 2 NSO3H…〔1〕. Preferably, R 1 and R 2 in the general formula 〔1〕 are each independently H or an alkyl group having 1 to 8 carbon atoms or a functional group containing a benzene ring.

[0073] As the aminosulfonic acid compound, for example, aminosulfonic acid (amide sulfuric acid) or its salt in which both R 1 groups and R 2 groups are hydrogen atoms; N-methylaminosulfonic acid, N-ethylaminosulfonic acid, N-propylaminosulfonic acid, N-isopropylaminosulfonic acid, N-butylaminosulfonic acid, etc., in which both R1 Based on R 2 Aminesulfonic acid or its salt in which one of the groups is a hydrogen atom and the other is an alkyl group having 1 to 8 carbon atoms; N,N-dimethylaminesulfonic acid, N,N-diethylaminesulfonic acid, N,N-dipropylaminesulfonic acid, N,N-dibutylaminesulfonic acid, N-methyl-N-ethylaminesulfonic acid, N-methyl-N-propylaminesulfonic acid, etc. for the two Rs 1 Based on R 2 Aminesulfonic acid or its salt in which both groups are alkyl groups having 1 to 8 carbon atoms, etc., and is not limited to these. One or more than two selected from these can be used.

[0074] As an example of the production of chloramine compounds, for example, a method of mixing an aqueous solution of a stabilizer (for example, an aqueous solution of an aminesulfonic acid compound, etc.) and an aqueous solution of a chlorine-based oxide (for example, an aqueous solution of sodium hypochlorite, etc.) in the presence of a base can be cited. The chloramine compound can be formed from at least a stabilizing compound and a chlorine-based oxide. The pH value during the production of the chloramine compound or the pH value of the agent containing the produced chloramine compound is preferably 12 or more, more preferably 13 or more. For example, as an example of the production of sodium chloraminesulfonate, the method described in [Examples] of Patent Document 2 (WO 2011 / 125762; Japanese Patent No. 5720964 Gazette) can be referred to.

[0075] The usage ratio of the chlorine-based oxide and the stabilizing compound (for example, an aminesulfonic acid compound, etc.) is not particularly limited. Relative to 1 mole of the total chlorine concentration (Cl2) of the chlorine-based halogen compound, it is preferably 0.5 mole to 5.0 moles of the chlorine stabilizing compound (preferably an aminesulfonic acid compound), more preferably 0.5 mole to 2.5 moles, and even more preferably 1.0 mole to 2.2 moles. The said usage ratio can also be the content ratio in the agent.

[0076] As the aminesulfonic acid compound, more preferably R 1 , R 2 are respectively H, the narrow sense of aminesulfonic acid. N-methylaminesulfonic acid, N,N-dimethylaminesulfonic acid, N-phenylaminesulfonic acid, chloramine T, etc. can also be used. Regarding the aminesulfonic acid compound, these aminesulfonic acids can be used in the state of free (powdered) acids, and can also be salts such as alkali metal salts such as sodium salts, potassium salts, and lithium salts. One or more than two selected from these can be used.

[0077] Chloraminesulfonic acid refers to chloraminesulfonic acid in which at least one hydrogen atom in the NH2 group of aminesulfonic acid (H2NSO2OH) is substituted by a chlorine atom. As chloraminesulfonic acid, for example, monochloraminesulfonic acid, dichloraminesulfonic acid, etc. can be cited.

[0078] The so-called chloraminesulfonate refers to a chloraminesulfonate formed by substituting at least one hydrogen atom in the OH group of amidosulfonic acid (H2NSO2OH) with a metal ion (for example, an alkali metal ion such as a lithium ion, a sodium ion, or a potassium ion).

[0079] Examples of the chloraminesulfonate include lithium chloraminesulfonate, sodium chloraminesulfonate, and potassium chloraminesulfonate, etc., and one or more than two selected from these can be used. Among these, sodium chloraminesulfonate is preferred.

[0080] In addition, as other chloramine compounds, chloramine T etc. can be used. In addition, one or more than two selected from these can be used.

[0081] <Stabilized bromide>

[0082] The so-called stabilized bromide is preferably a compound having at least one nitrogen atom or carbon atom bonded to a bromine atom (N-Br bond, C-Br bond), and is equivalent to a bound halogen compound. The so-called stabilized bromide is preferably a bromide that hardly undergoes changes due to decomposition etc. in water, and the generated bromide can stably exist in water.

[0083] Examples of the stabilized bromide include reaction products of "bromine-based oxides or bromine compounds, and reaction products of chlorine-based oxides" and "amidosulfonic acid compounds (stabilized amino compounds)", etc., but are not limited to these. Regarding the pH value during the production of the said reaction product or the pH value of the reaction product, an alkali is preferred, more preferably 11 or more, further preferably 12 or more, and still further preferably 13 or more. These can be commercially available products, or stabilized bromides obtained by known production methods can be used.

[0084] The bromine-based halogen compound is not particularly limited, and examples thereof include bromine (liquid bromine), bromine chloride, bromic acid, bromate, and hypobromous acid, etc., and one or more than two selected from these can be used.

[0085] The bromine compound is not particularly limited, and examples thereof include alkali metal bromides such as sodium bromide, potassium bromide, and lithium bromide, ammonium bromide, and hydrobromic acid, etc., and one or more than two selected from these can be used.

[0086] Regarding the chlorine-based halogen compound (chlorine-based oxide (for example, hypochlorite, chlorite, chlorate, perchlorate, trichloroisocyanuric acid chloride, etc.)) used in the stabilized bromide, the descriptions such as the "chlorine-based compound (preferably chlorine-based oxide)" of the said <chloramine compound> are applicable to these, and the structures etc. described above can be appropriately adopted. Among them, hypochlorite (for example, sodium hypochlorite) is preferred.

[0087] Regarding the "sulfamic acid compound", the description of the "sulfamic acid compound that constitutes the chlorosulfamic acid compound, which is the compound represented by R 1 R 2 NSO3H…〔1〕" and so on applies to these, and the structure and the like described can be suitably adopted. Among the "sulfamic acid compounds", sulfamic acid or its salt is preferred.

[0088] As an example of the production of the stabilized bromide, for example, the following method can be cited: A mixed solution 1 is prepared by mixing an aqueous solution of sodium bromide and sodium hypochlorite. On the other hand, a mixed solution 2 is prepared by mixing an aqueous solution of sulfamic acid and an aqueous solution of sodium hydroxide. The mixed solution 1 and the mixed solution 2 are mixed in the presence of a base.

[0089] For example, bromamine or bromaminesulfonic acid containing an ammonium salt and bromine, and bromaminesulfonate, and DBNPA etc. as other compounds can be used.

[0090] 1-1-3. Optional components

[0091] In addition, within the range that does not impair the effects of this embodiment, optional components or optional agents can also be suitably included in the agent containing the combined halogen compound. As the optional components or optional agents, for example, corrosion inhibitors, scale inhibitors, slime inhibitors, solvents or dispersion media such as water, dispersant enzymes, bactericides, and antifoaming agents, etc. can be cited, but it is not limited thereto. In addition, various agents that can be used in a normal water system or water treatment can also be used. One or more than two can be suitably selected from these optional components or optional agents. In addition, the optional components or optional agents can be further suitably added or used independently of the addition or use of the combined halogen compound or the agent containing the compound.

[0092] 1-1-4. Adjustment or generation of the combined halogen compound

[0093] <Molar ratio of halogen-based compound to stabilized compound>

[0094] When generating the combined halogen compound, the molar ratio of the halogen compound to the stabilizing compound (preferably an amino compound) (the molar ratio of the stabilizing compound (preferably an amino compound) / halogen compound) is not particularly limited. As a preferred lower limit value, it is preferably 0.5 or more, more preferably 1.0 or more. In addition, as a preferred upper limit value, it is preferably 5.0 or less, more preferably 2.2 or less, still more preferably 2.0 or less, and further preferably 1.5 or less. The combined halogen compound is preferably a compound generated by adjusting or mixing in a manner such that the molar ratio of the stabilizing compound / halogen compound (more preferably 1.0 or more) is achieved in the generation of a medicament or a water system. The molar ratio can be the molar ratio in the medicament or the molar ratio when used in a water system. In addition, the molar amount of the halogen compound is preferably set to 1 mole of the total chlorine concentration (Cl2). As a manufacturing example, the method described in Patent Document 2 (WO2011 / 125762) can be referred to.

[0095] The pH value of the reaction product or medicament containing the combined halogen compound is preferably 12 or more, more preferably 13 or more. The pH value can also be the pH value when generating the reaction product. The usage ratio can be the usage ratio when used in a water system or the content ratio in the medicament.

[0096] 1-2. Organic slime inhibitor

[0097] In a water system, there is a high possibility that an organic slime inhibitor generates or promotes the generation of endotoxin. However, by using the combined halogen compound used in this embodiment in combination, the generation or concentration reduction of endotoxin when using an organic slime inhibitor can be inhibited. Furthermore, the use of the combined halogen compound in a water system when used in combination with an organic slime inhibitor can be continuous or intermittent, and can also be in the same period or different periods as the use of the organic slime inhibitor. In this embodiment, the use of the combined halogen compound when used in combination with an organic slime inhibitor has the following very excellent effects: Even if it is an intermittent addition and the addition is within a short time, effects such as endotoxin generation inhibition can be exerted.

[0098] The organic slime inhibitor or its components (hereinafter, also referred to as "organic slime inhibiting compound") is not particularly limited. For example, isothiazoline compounds, halogenated cyanoacetamide compounds, aldehyde compounds, and oxime compounds represented by tetrazolyl oxime or dichloroethylglyoxime dioxime can be cited, and one or more of these can be used. In addition, the organic slime inhibitor can also be a medicament containing one or more compounds selected from these. The organic slime inhibitor or the compound used in the organic slime inhibitor can use commercially available products or compounds obtained by known manufacturing methods.

[0099] <Isothiazoline compound>

[0100] As the isothiazoline compound, there is no particular limitation. For example, 5-chloro-2-methyl-4-isothiazolin-3-one (Cl-MIT), 2-methyl-4-isothiazolin-3-one (2-methyl-4-isothiazoline-3-one, MIT), 2-ethyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-ethyl-4-isothiazolin-3-one, 5-chloro-2-tert-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-cyclohexyl-4-isothiazolin-3-one, etc. can be mentioned, and one or more than two of these can be used. In addition, as the isothiazoline compound, a complex compound of the above isothiazoline compound and magnesium chloride, magnesium nitrate, copper chloride, copper nitrate, calcium chloride, etc. can also be used. One or more than two of these can be selected and used.

[0101] Among the isothiazoline compounds, 5-chloro-2-methyl-4-isothiazolin-3-one (Cl-MIT), 2-methyl-4-isothiazolin-3-one (MIT), or a mixture of these is preferred, and it is more preferred to use at least Cl-MIT.

[0102] <Halogenated cyanoacetamide compound>

[0103] As the halogenated cyanoacetamide compound, there is no particular limitation. For example, 2-halo-3-aminopropionamides such as 2-chloro-3-aminopropionamide and 2-bromo-3-aminopropionamide; 2,2-dihalo-3-aminopropionamides such as 2,2-dichloro-3-aminopropionamide, 2,2-dibromo-3-aminopropionamide (DBNPA), and 2-chloro-2-bromo-3-aminopropionamide; N-C1-3 alkyl-2-halo-3-aminopropionamides such as N-methyl-2-chloro-3-aminopropionamide and N-methyl-2-bromo-3-aminopropionamide; N-C1-3 alkyl-2,2-dihalo-3-aminopropionamides such as N-methyl-2,2-dichloro-3-aminopropionamide and N-methyl-2,2-dibromo-3-aminopropionamide, etc. One or more than two of these can be selected and used.

[0104] In addition, the halogenated cyanoacetamide compound can also be a compound represented by NC-CX 1 X 2 -(C=O)-NHR 3 ... [2]. In the general formula [2], X 1 , X 2 each independently represents a halogen atom or a hydrogen atom, and at least one of X 1 , X 2 is a halogen atom. R3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. As the halogen atom, a chlorine atom or a bromine atom can be mentioned, and a bromine atom is preferred. As the C1-3 alkyl group, either a straight-chain or a branched-chain one can be used, and examples include: methyl, ethyl, n-propyl, isopropyl, etc. One or more than two of these can be used.

[0105] Among the halogenated cyanoacetamide compounds, dihalogenated amino propionamides are preferred, and among these, 2,2-dibromo-3-amino propionamide (DBNPA) is even more preferred.

[0106] <Aldehyde compound>

[0107] As the aldehyde compound, there is no particular limitation, and examples include: monoaldehyde compounds such as acetaldehyde; dialdehyde compounds such as glyoxal and ortho-phthalaldehyde, etc. One or more than two of these can be used.

[0108] Among the aldehyde compounds, dialdehyde compounds are preferred, and among the dialdehyde compounds, glutaraldehyde is preferred from the viewpoint of high safety.

[0109] <Oxime compound>

[0110] As the oxime compound, there is no particular limitation, and examples include: oxime compounds having a tetrazole ring (CH2N4) (for example, tetrazolyl oxime, etc.), and halogenated oxime compounds (for example, dichloro glyoxal dioxime, etc.), etc. One or more than two of these can be used. The oxime compound is a compound having a structure represented by >C=N-OH in the molecule.

[0111] As the oxime compound having a tetrazole ring, for example, picarbutrazox (molecular formula: C 20 H 23 N7O3, molecular weight: 409.44, CAS No. 500207-04-5), etc. can be mentioned.

[0112] As the halogenated oxime compound, for example, dichloro glyoxal dioxime, α-chlorobenzaldehyde oxime, α-chlorobenzaldehyde oxime acetate, 4-hydroxyphenyl-α-ketoacetylhydroxamic acid chloride (alias PARACLOX), etc. can be mentioned. One or more than two of these can be used.

[0113] Among the organic slime inhibitors, one or more than two selected from 2,2-dibromo-3-amino propionamide (DBNPA), 5-chloro-2-methyl-4-isothiazolin-3-one (Cl-MIT), and 2-methyl-4-isothiazolin-3-one (MIT), or a mixture of these, glutaraldehyde, etc. are preferred.

[0114] In addition, within the scope that does not impair the effects of this embodiment, arbitrary components or arbitrary agents may be appropriately included in the organic slime inhibitor. Additionally, the structure described in the "1-1-3. Arbitrary Components" can be appropriately adopted, etc.

[0115] 1-3. Presence, content, and use of the bound halogen compound in the water system

[0116] In this embodiment, by causing the bound halogen compound to be present in the water system or adjusting the amount present, the effects of inhibiting endotoxin generation and / or inhibiting biofouling can be exerted, or the cost of using chemicals can be reduced. By the method of this embodiment, the generation of endotoxin in the treated water can also be inhibited or the increase in endotoxin concentration can be inhibited, such treated water can be obtained, and the endotoxin concentration in the treated water can also be reduced.

[0117] In this embodiment, the presence of the bound halogen compound in the water system can be controlled. Thus, the presence, generation, or amount present of the bound halogen compound in the water system can also be adjusted or controlled, and the adjustment or control can be executed by the control unit.

[0118] In this embodiment, by adjusting the amount present of the bound halogen compound in the water system, etc., the total halogen concentration of the water system, the endotoxin concentration of the water system, the number of or the presence ratio of Gram-negative bacteria in the water system, etc. can also be adjusted. As "adjusting the amount present of the bound halogen compound", there is no particular limitation, and examples include: starting or stopping (ending) the addition of the bound halogen compound, increasing or decreasing the addition amount of the bound halogen compound, increasing or decreasing the amount present or the use concentration of the bound halogen compound, adjusting the total halogen concentration, etc.

[0119] As the treated water obtained by this embodiment, preferably, it is treated water with reduced endotoxin concentration, inhibited endotoxin generation, removed endotoxin, etc. There is no particular limitation, and examples include tap water, medical water (e.g., dialysis water, cleaning water, etc.), pharmaceutical purified water, etc., and one or more than two of these can be selected.

[0120] In this embodiment, the location of the water system where the bound halogen compound is present is not particularly limited and can be any location, device, system, or process.

[0121] In addition, in the present embodiment, the location where one or more compounds selected from the bound halogen compounds, halogen-based compounds, and stabilizing compounds (hereinafter, also referred to as "compounds used in the present embodiment" or "the compounds") are added, or the location where the bound halogen compounds present in the water system are generated is not particularly limited. Preferably, it is the water in the water system, and substances manufactured as chemicals can also be added at locations outside the water system (such as chemical factories) to generate them. As a preferred form, it is preferred to add the compounds used in the present embodiment to the water system before membrane treatment; and / or generate the bound halogen compounds in the water system. The addition location of the compounds, chemicals, etc. can also be the generation location of the bound halogen compounds used in the present embodiment. In addition, in the present embodiment, the chemicals can also contain the compounds used in the present embodiment, and the chemicals can be added to the water system.

[0122] The water system in which the bound halogen compounds are present is more preferably a water treatment system for performing water treatment, and further preferably a membrane treatment system for performing membrane treatment.

[0123] In addition, in the present embodiment, when the bound halogen compounds are present in the water system, within the range that does not impair the effects of the present embodiment, one or more compounds selected from bound halogen compounds with a molecular weight less than 60, organic compounds, and other chemicals for inhibiting biofilms, etc. can be used, or they can be contained together in the form of a single-form chemical.

[0124] <Total halogen concentration in the water system>

[0125] In the present embodiment, it is preferred to control the presence of the bound halogen compounds in the water system to adjust the total halogen concentration in the water system to a specified concentration, whereby a water system (treated water, circulating water, etc.) with a desired concentration can be prepared.

[0126] In addition, the total halogen concentration in the chemicals containing the bound halogen compounds is not particularly limited. Preferably, when the chemicals are added to the water system, the total halogen concentration in the water system can be adjusted to a desired concentration.

[0127] The total halogen concentration (mg / 1 L of the water system; mg-Cl2 / L in terms of total chlorine concentration) in the water system is not particularly limited. Regarding the total halogen concentration, as a preferable lower limit value, it is preferably 0.01 mg / L or more, more preferably 0.05 mg / L or more, still more preferably 0.1 mg / L or more. Additionally, as a preferable upper limit value, it is preferably 100 mg / L or less, more preferably 50 mg / L or less, still more preferably 40 mg / L or less, further more preferably 30 mg / L or less, and more preferably 20 mg / L or less. As the preferable numerical range, it is preferably 0.01 mg / L to 50 mg / L, and more preferably 0.1 mg / L to 20 mg / L. Thus, in the water system, better biofilm inhibition or biofouling inhibition can be achieved, and endotoxin generation inhibition can also be achieved. Therefore, treated water with a lower endotoxin concentration can be obtained more preferably.

[0128] In the present embodiment, the period (hour (hour) / day) during which the combined halogen compound is used in the water system is not particularly limited. As a preferable lower limit value, it is preferably 0.1 h / day or more, more preferably 0.25 h / day or more, still more preferably 1 h / day or more, further more preferably 3 h / day or more or 6 h / day or more. Additionally, the number of days of the use period is not particularly limited and can be about 1 day to 7 days. Further, by using it in combination with an organic slime control agent, the use period can also be reduced, preferably 0.1 h / day to 2 h / day, and more preferably 0.25 h / day to 1 h / day. In addition, the use period can be the existence period or the addition period.

[0129] In this embodiment, the use concentration of the organic slime control agent relative to the water system (mg (based on the mass of the agent) / 1 L of the water system) is not particularly limited. As a preferable lower limit value, it is preferably 0.001 mg / L or more, more preferably 0.01 mg / L or more, further preferably 0.03 mg / L or more, and further preferably 0.05 mg / L or more. In addition, as a preferable upper limit value, it is preferably 1000 mg / L or less, more preferably 100 mg / L or less, and further preferably 50 mg / L or less. As a preferable numerical range, it is preferably 0.01 mg / L to 100 mg / L. In addition, the use period (hours (hour) / day) of the organic slime inhibitor relative to the water system is not particularly limited. As a preferable lower limit value, it is preferably 1 h / day or more, more preferably 3 h / day or more, further preferably 6 h / day or more, and further more preferably 12 h / day or more, more preferably 18 h / day or more or 20 h / day or more. In addition, as the preferable upper limit value, it is preferably 24 h / day or less, 23.5 h / day or less, 23 h / day or less, or 22 h / day or less. In this embodiment, in order to use the organic slime control agent outside the use period of the combined halogen compound, the two can be used in different periods in such a way that their use periods do not overlap, or the use periods of the two can overlap.

[0130] <Endotoxin concentration in the water system>

[0131] In this embodiment, the endotoxin concentration in the water system can be inhibited or reduced. In this embodiment, it is preferable to control the presence of the combined halogen compound in the water system until the water system reaches the desired endotoxin concentration, whereby a water system or treated water with a desired low endotoxin concentration can be obtained. In addition, the endotoxin concentration in the water system can also be set as the endotoxin concentration of the treated water. In addition, as an index for endotoxin inhibition, for example, the endotoxin concentration at the time of control (without adding the agent) can be set to 100%.

[0132] In addition, regarding the endotoxin concentration (EU / mL) in the water system, as its preferable upper limit value, it is preferably 90 EU / mL or less, more preferably 80 EU / mL or less, more preferably 70 EU / mL or less, more preferably 60 EU / mL or less, more preferably 50 EU / mL or less, more preferably 40 EU / mL or less, further preferably 30 EU / mL or less, further more preferably 20 EU / mL or less, more preferably 15 EU / mL or less, more preferably 10 EU / mL or less, more preferably 9 EU / mL or less, more preferably 8 EU / mL or less.

[0133] <Each condition in the water system>

[0134] The pH value of the water system is not particularly limited, preferably 3 to 9, more preferably 4 to 9, and still more preferably 5 to 9. The pH value can also be adjusted using a pH adjuster.

[0135] The water temperature of the water system is not particularly limited, preferably 4°C to 50°C, and still more preferably 10°C to 40°C.

[0136] The total organic carbon (TOC) of the water system is not particularly limited, preferably 100 mg / L or less, more preferably 50 mg / L or less, still more preferably 10 mg / L or less, and even more preferably 5 mg / L or less. It is ideal that the TOC is low.

[0137] The oxidation-reduction potential (ORP) of the water system is not particularly limited, preferably 200 mV to 600 mV, and more preferably 200 mV to 400 mV.

[0138] <Status (index) of Gram-negative bacteria in the water system>

[0139] In the present embodiment, it is preferable to control the presence (e.g., inclusion or use) of the bound halogen compound in the water system based on the status of Gram-negative bacteria in the water system. "Presence" can be "generation". The control can also be executed by a control unit.

[0140] Furthermore, it is more preferable to use one or more selected from the bound halogen compound, halogen-based compound, and stabilizing compound in such a manner that the total halogen concentration in the water system becomes the desired concentration and / or in such a manner that the endotoxin concentration in the water system becomes the desired concentration (relative ratio, EU / mL). In addition, the endotoxin concentration in the water system can also be the endotoxin concentration in the treated water.

[0141] In addition, the addition and addition order of the compound for adjusting the desired concentration are not particularly limited. The bound halogen compound can be added alone, the halogen-based compound and / or stabilizing compound for adjustment can be added alone, or it can be a combination of these. The addition of the compound can be at the same time or at different times. Regarding the combination, for example, the halogen-based compound and / or stabilizing compound for adjustment can be added after adding the bound halogen compound, the bound halogen compound can be added after adding the halogen-based compound and / or stabilizing compound for adjustment, or it can be a combination of these, without particular limitation.

[0142] As the state of Gram-negative bacteria in the water system, it is preferably one or more selected from the presence ratio of all Gram-negative bacteria in the flora, the presence ratio of the Gram-negative bacteria in the whole of Gram-negative bacteria and Gram-positive bacteria excluding bacteria that cannot be discriminated as Gram-negative or positive, the presence ratio of individual Gram-negative bacteria, the types of Gram-negative bacteria, and the number of all or individual Gram-negative bacteria. Among them, from the viewpoint of being able to suppress endotoxin production with good precision, the presence ratio of all Gram-negative bacteria in the flora is preferred. In addition, from the viewpoints of simplicity and ease of measurement, the number of all or individual Gram-negative bacteria is preferred. In addition, as a means for discriminating the state of Gram-negative bacteria in the water system, amplicon sequencing data analysis (QIIME2) can be cited.

[0143] In addition, as the index, it is preferably at least using or containing bacteria of the genus Pseudomonas and / or the genus Cupriavidus.

[0144] In the present embodiment, "all Gram-negative bacteria" refers to all Gram-negative bacteria that can be detected by a bacterial measurement method (preferably a genetic analysis method), and "individual Gram-negative bacteria" refers to a group of Gram-negative bacteria that can be detected by a bacterial measurement method (preferably a genetic analysis method) and are classified into each bacterial group such as genus bacteria.

[0145] In the present embodiment, it is further preferred to use the state of Gram-negative bacteria in the water system as an index and determine the presence (preferably the content or usage amount) of the bound halogen compound in the water system based on the index. From the viewpoints of suppressing endotoxin production and reducing endotoxin concentration, it is preferred to make Gram-negative bacteria not dominant by using the determination process or method.

[0146] Regarding the presence or generation (preferably the content or usage amount (list of determination items)) of the bound halogen compound in the water system to be determined, there is no particular limitation. For example, one or more selected from the time points of use (start, maintenance, end, etc.), usage period, usage amount, adjustment of the total halogen concentration, etc. can be cited.

[0147] As the index, the state of Gram-negative bacteria in the water system is preferred. The Gram-negative bacteria are not particularly limited and are preferably corresponding or changed for each water system based on the results of flora analysis or bacterial examination, etc. of each site of the water system. For example, dominant bacteria can be selected according to the flora of a certain water system and the Gram-negative bacteria and their presence ratios occupying therein.

[0148] In the present embodiment, by controlling the presence or generation (e.g., inclusion, use) of the combined halogen compound in the water system based on the index, effects such as inhibition of endotoxin generation, inhibition of biofilm formation, and inhibition of biofouling in the water system can be exerted. Thereby, the endotoxin concentration in the water system or the treated water obtained can be reduced. Therefore, prevention or improvement of various symptoms or various diseases caused by endotoxins in the treated water can also be expected. By using the present embodiment, treated water used in medical applications and the like can also be manufactured, generated, and provided.

[0149] As a preferred form of the present embodiment, it is more preferably that when the presence ratio of Gram-negative bacteria in the flora in the water system is equal to or higher than a specified value, the combined halogen compound is present in the water system, and the specified value is set within the range of 60% to 10%. In addition, as a preferred form of the present embodiment, it is more preferably that when the number of bacteria in the water system is equal to or higher than a specified value, the combined halogen compound is present in the water system, and the specified value is set within the range of 1,000 cfu / mL to 10 cfu / mL. In addition, these presence ratios and the number of bacteria can be appropriately combined, and the compound can be present in the water system until either one or both of them reach the specified value.

[0150] <Status of Gram-negative bacteria in the water system: Presence ratio in the flora in the water system>

[0151] In the present embodiment, the value of the presence ratio in the flora in the water system as an index can be appropriately set. Preferably, the presence ratio of all Gram-negative bacteria in the flora in the set water system is set as the "specified value". In addition, since all bacteria are composed of negative bacteria and positive bacteria, the presence ratio of Gram-positive bacteria in the flora can also be set as the "specified value" (e.g., 100% of the flora - 10% of all Gram-negative bacteria) in consideration of the presence ratio of Gram-negative bacteria involved in endotoxin generation. However, since Gram-negative bacteria are involved in endotoxin generation, it is ideal to use the "presence ratio of Gram-negative bacteria" as the benchmark.

[0152] Generally, when the proportion of Gram-negative bacteria increases, the endotoxin concentration in the water system or treated water is likely to increase. On the other hand, according to the [Examples] described below, by using a combined halogen compound, the proportion of all Gram-negative bacteria in the flora in the water system can be significantly reduced, and the endotoxin concentration in the water system can also be significantly reduced. Therefore, as a preferred form of the present embodiment, it is preferable to set the "proportion of all Gram-negative bacteria in the flora in the water system" to a "specified value", and when it is "above the specified value", add, contain, or use the compound (preferably the combined halogen compound, halogen-based compound, or stabilizing compound) in the water system, and in order to inhibit endotoxin generation or reduce the endotoxin concentration, make the combined halogen compound present in the water system (such as increasing the addition or use amount of the compound, or increasing the total halogen concentration).

[0153] In the present embodiment, from the viewpoint of inhibiting endotoxin generation, it is more preferable to set the proportion (specified value) of all Gram-negative bacteria in the flora to a lower value. It is preferably set to 60% or more, more preferably 50% or more, further preferably 40% or more, more preferably 30% or more, more preferably 20% or more, further preferably 10% or more, or 5% or more. Two or more of these set values can be appropriately combined and set within the range of the set value. For example, the specified value can be set within the range of 60% to 10%.

[0154] In addition, for example, when setting the proportion of Gram-negative bacteria in the flora in the water system to a desired specified value (such as 10% or more), it is preferable to make the combined halogen compound present (such as starting to use the compound or increasing the use amount) or control the amount of the combined halogen compound present to be the desired set value. At this time, for example, the concentration of the combined halogen compound in the water system can be further increased and / or the presence period of the combined halogen compound in the water system can be further extended to reach the desired specified value.

[0155] In addition, in the present embodiment, as the set value of "the proportion of Gram-negative bacteria in the overall Gram-negative and Gram-positive bacteria excluding bacteria that cannot be distinguished as Gram-negative or positive", the set value of the "proportion of all Gram-negative bacteria in the flora (specified value)" can be appropriately adopted. For example, when it is 50% or more, by adjusting the proportion of Gram-negative bacteria to a lower value (such as 20% or less than 10%), endotoxin generation can be inhibited.

[0156] In addition, in a case where it does not correspond to "equal to or greater than the specified value of the presence ratio" (that is, in a case of "equal to or less than the specified value"), from the viewpoints of cost reduction of the compound or agent, suppression of the generation of resistant bacteria, etc., the use of the compound in the water system may also be terminated, or the amount of the bound halogen compound present or the amount of use of the compound may be reduced. Furthermore, based on the case where "equal to or greater than the specified value" is set to "equal to or less than the specified value", it may also be set to terminate the use of the compound or the bound halogen compound, etc. in the water system or reduce the amount of use. For example, it may be set to 60% to 10% or less, or 10% or less, and in the case of "equal to or less than the specified value", the use of the compound in the water system may be terminated, or the amount of the bound halogen compound present or the amount of use of the compound may be reduced.

[0157] In addition, for example, the type of Gram-negative bacteria may be selected according to the dominant rank in the flora in the water system for each water system. For example, it may be selected from the top of the presence ratio of Gram-negative bacteria up to the 2nd, 3rd, 4th, or 5th place, more preferably from the top up to the 2nd or 3rd place, etc. In addition, individual Gram-negative bacteria may be used as an index for each water system, and each Gram-negative bacteria and its presence ratio in the flora in the water system may also be selected and appropriately set. In such a case, discriminant analysis and selection may be performed using amplicon sequencing data analysis (QIIME2). For example, "equal to or greater than the specified value" of a certain Gram-negative bacteria or multiple Gram-negative bacteria at the top selected by discriminant analysis is preferably set to 5% or more, more preferably 10% or more, further preferably 20% or more, more preferably 30% or more, or 40% or more. At this time, it is preferable to control the presence or generation of the bound halogen compound in the water system or the amount of the compound present. In addition, as described above, in a case where it does not correspond to the numerical value or in a case where "equal to or greater than the specified value" is set to "equal to or less than the specified value", it may also be set to terminate the use of the compound in the water system or reduce the amount of use. The specified value may also be set within a range of a specified value (for example, 5% to 40%) obtained by appropriately combining two or more of these set values.

[0158] <Status of bacteria in the water system: Number of bacteria in the water system>

[0159] In the present embodiment, the numerical value of the number of bacteria in the water system, the number of all Gram-negative bacteria, or the number of individual Gram-negative bacteria used as an index may be appropriately set, and preferably, the number of all bacteria or the number of Gram-negative bacteria in the set water system is set to the "specified value".

[0160] In the present embodiment, from the viewpoint of suppressing endotoxin production, the lower the number of bacteria (prescribed value) in the water system is set, the more preferable it is. It is preferably set to 10,000 cfu / mL or more, more preferably 1,000 cfu / mL or more, further preferably 500 cfu / mL or more, still further preferably 100 cfu / mL or more or 50 cfu / mL or more, more preferably 30 cfu / mL or more, 20 cfu / mL or more or 10 cfu / mL or more. Two or more of these set values can be appropriately combined and set within the range of the set value. For example, the prescribed value can be set within the range of 1,000 cfu / mL to 10 cfu / mL. In addition, the "number of bacteria in the water system" of the prescribed value can be replaced with the "number of all Gram-negative bacteria in the water system" or the "number of individual Gram-negative bacteria".

[0161] As a preferred form of the present embodiment, it is preferable to set the number of bacteria in the water system to the "prescribed value", and when it is above the "prescribed value", add, contain or use the compound in the water system, and in order to suppress endotoxin production or reduce the endotoxin concentration, control the presence of the bound halogen compound (the amount of the compound present) in the water system. In addition, when it does not correspond to above the "prescribed value" (that is, when it is below the "prescribed value"), it is preferable to discontinue the use of the compound in the water system, reduce the usage amount, etc. For example, when the number of bacteria in the water system is 10 cfu / mL or more (prescribed value), it is preferable to make the compound or the bound halogen compound, etc. present and adjust it to less than the prescribed value (10 cfu / mL). In addition, for the setting of the prescribed value, the adjustment (increase or decrease of concentration and presence period) or control, etc. of the compound, the <state of Gram-negative bacteria in the water system: the presence ratio in the flora in the water system> can be appropriately adopted.

[0162] In addition, in the present embodiment, the "water system" of the number of bacteria in the water system may be the "treated water" after treatment, that is, it may be the number of bacteria in the treated water. In addition, as shown in the [Examples] described later, as shown in the control of the water system (raw water), at least half to more than 70% of all bacteria are Gram-negative bacteria. Therefore, "all bacteria" including both "Gram-negative bacteria" and Gram-positive bacteria can also be used as an index, and the number of Gram-negative bacteria can be appropriately used, and the number of all bacteria is set above a specified value. More preferably, the specified value is set within the range of 1000 cfu / mL to 10 cfu / mL. When the number of bacteria in the water system is equivalent to or higher than the specified value, it is preferable to use the combined halogen compound in the water system, and in order to inhibit endotoxin generation or reduce the endotoxin concentration, the presence of the combined halogen compound (the amount of the compound present) in the water system is controlled. In addition, in the case where it is not equivalent to the "above the specified value" (that is, the case of "below the specified value"), it is preferable to discontinue the use of the compound in the water system, reduce the usage amount, etc.

[0163] In addition, in the case where it is not equivalent to the "above the specified value of the number of bacteria" (that is, the case of "below the specified value or less than the specified value"), from the viewpoints of cost reduction of the compound or agent, inhibition of the generation of resistant bacteria, etc., the use of the combined halogen compound in the water system can also be discontinued, or the usage amount of the combined halogen compound can be reduced. Furthermore, based on the case where "above the specified value" is set to "below the specified value", it can be set to discontinue the use of the combined halogen compound in the water system or reduce the usage amount. For example, it is preferable to set the specified value within the range of 1,000 cfu / mL to 10 cfu / mL. In the case of "below the specified value", from the viewpoints of cost reduction of the compound or agent, inhibition of the generation of resistant bacteria, etc., the use of the compound or the combined halogen compound in the water system can also be discontinued, or the usage amount of the combined halogen compound can be reduced.

[0164] Gram-negative bacteria, which are preferably used as indicators in this embodiment, include, for example, at least one or more of the genus Pseudomonas, the genus Cupriavidus, the genus Methyloversatilis, the genus Sphingopyxis, the genus Rhizobacter, the genus Novosphingobium, the genus Xanthobacteraceae, the genus Berkiella, the genus Neochlamydia, the genus Legionella, the genus Vermiphilaceae, the genus Sphingomonas, the genus Phenylobacterium, the genus Nannocystis, the genus Bradyrhizobium, and the genus Hyphomicrobium. All of these can be regarded as "all gram-negative bacteria". Among them, it is preferably to use at least the genus Pseudomonas and / or the genus Cupriavidus as indicators. With fewer indicators, a higher presence ratio in the bacterial flora, and fewer numbers of the bacteria used as indicators, the operation efficiency of bacterial inspection is better, and it is easier to more simply and accurately judge the application period and dosage of the agent.

[0165] The water system is preferably controlled to have the combined halogen compound present when at least one selected from the gram-negative bacteria, or the genus Pseudomonas and / or the genus Cupriavidus is set as an indicator and the indicator is present, or when a desired numerical range (threshold value) is set and is met.

[0166] <Method for measuring bacteria in water system>

[0167] In this embodiment, the state of bacteria in the water system (flora analysis, classification, bacterial count, identification, etc.) can be determined using well-known methods for detecting or measuring bacteria. As methods for detecting or measuring bacteria, for example, one or more methods selected from the agar plate method (Colony Forming Unit; CFU / mL), MPN method (Most Probable Number: MPN / 100mL), antibody method (enzyme labeling, fluorescence labeling, radioactive substance labeling, etc.), quantitative polymerase chain reaction (PCR) method (copies / mL), Terminal Restriction Fragment Length Polymorphism (T-RFLP) method, immunoblotting method, Western blotting method, enzyme-linked immunosorbent assay (ELISA) method, mass spectrometry method, gene analysis method, etc. can be used for qualitative and quantitative confirmation. For example, a Gram-negative bacteria ELISA kit, determination of 16S rDNA concentration using gene analysis method, and analysis of amplicon sequencing data (QIIME2), etc. can be cited.

[0168] The gene analysis method is not particularly limited. For example, one or more methods selected from Western blotting, ELISA, deoxyribonucleic acid (DNA) chip, fluorescence in situ hybridization (FISH) analysis, immunostaining method, and other known gene analysis methods [e.g., Sanger sequencing analysis, Next Generation Sequencing (NGS), PCR, Ligase chain reaction (LCR), Strand displacement amplification (SDA), Nucleic acid sequence-based amplification (NASBA), Isothermal and chimeric primer-initiated amplification (ICAN), Loop-mediated isothermal amplification (LAMP) method, etc.] can be mentioned.

[0169] In the present embodiment, the object when confirming (detecting, measuring, etc.) the state of Gram-negative bacteria in the water system is not particularly limited as long as it is the water system. For example, water in the water system such as treated water or circulating water, and biofilms present in the water system can be mentioned. As the biofilm, plankton in water, or attachments on pipes, devices, membranes, etc. of the water system can be mentioned.

[0170] In addition, the place for confirming (detecting or measuring) the flora is not particularly limited as long as it is the water system, and the place where the biofilm exists is preferred. As the place where the biofilm exists, pipes, flow paths, water storage tanks, membranes, and membrane treatment devices, etc. can be mentioned, and the place where attachment or accumulation occurs is preferred. The collection of the biofilm can be appropriately carried out by known methods. For example, filtration and concentration of plankton or scraping of attachments can be mentioned.

[0171] 1-4. Examples of the present embodiment

[0172] Examples of the present embodiment will be described below, but the present embodiment is not limited thereto.

[0173] Examples of the membrane treatment method, biofilm inhibition method, biological fouling inhibition method, endotoxin generation inhibition method, etc. in the present embodiment are described below, but are not limited to these. The control unit used in the present embodiment is configured to execute the method in the present embodiment, and the method in the present embodiment may be appropriately executed by an operator (person) instead of the control unit. The control mechanism can perform feedback control by performing adjustments or controls such as such increases and decreases.

[0174] <Example 1 of the Present Embodiment>

[0175] Example 1 of the present embodiment is described below, but the present embodiment is not limited thereto.

[0176] Example 1 of the present embodiment is a biofilm inhibition method, which includes:

[0177] a step of measuring bacteria in the water system; and

[0178] a step of controlling the amount of a combined halogen compound formed by at least using a halogen-based compound and a stabilized amino compound in the water system based on the measurement result of the bacteria,

[0179] The method is preferably a biofilm inhibition method in a water system in which Gram-negative bacteria are present. The control unit can control each step or each part, etc. to execute the method.

[0180] In addition to being a biofilm inhibition method, Example 1 of the present embodiment may also be one or more selected from a membrane treatment method, a biological fouling inhibition method, an endotoxin generation inhibition method, an endotoxin concentration reduction method, a method for producing treated water with a reduced endotoxin concentration, etc. When controlling the amount of the combined halogen compound present or the use of the compound, examples include increasing or decreasing the addition amount or use amount of the compound or a medicament containing the compound, increasing or decreasing the total halogen concentration, etc. The compound is one or more selected from the combined halogen compound, the halogen-based compound, and the stabilized compound (preferably an amino compound).

[0181] Example 1 of the present embodiment preferably further includes a step of performing membrane treatment on the treated water containing the combined halogen compound, and more preferably further includes a step of recovering the treated water in which endotoxin generation is inhibited by the membrane treatment. At this time, Embodiment 1 of the present embodiment may also be a membrane treatment method.

[0182] In addition, Example 1 of the present embodiment may also further include a step of circulating the circulating water containing the combined halogen compound, and furthermore, the circulating water is more preferably circulating water in which endotoxin generation is inhibited or the concentration is reduced.

[0183] As a more preferred form of Example 1 of the present embodiment, based on the results of the bacteria measurement of the water system, the following situations can be controlled: when the state of Gram-negative bacteria is equal to or higher than the set specified value, increase the amount of the combined halogen compound present in the water system (turn on (ON) the inclusion or use), and / or when it does not correspond to being equal to or higher than the specified value, reduce the amount of the combined halogen compound present in the water system (turn off (OFF) the inclusion or use). "The situation where it does not correspond to being equal to or higher than the specified value" can be a situation where the state of Gram-negative bacteria is equal to or lower than the specified value, or becomes equal to or lower than the specified value. In order to increase the amount of the combined halogen compound present in the water system, the use of the compound can be started, and in order to reduce the amount, the use of the compound can be terminated (ended). Additionally, the range of the specified value for maintaining the amount of the combined halogen compound present in the water system can be further set between "equal to or higher than the specified value" and "equal to or lower than the specified value".

[0184] In this way, based on the results of the bacteria measurement of the water system, the control of the presence (inclusion or use), turning on, and turning off of the combined halogen compound in the water system can be simply and accurately performed continuously or intermittently. As the control of the presence, for example, addition or non-addition of the compound or the medicament containing the compound, increase or decrease in the usage amount of the compound or the medicament containing the compound, increase or decrease in the total halogen concentration, etc. can be cited, but it is not limited thereto.

[0185] A more preferred state of the Gram-negative bacteria is to use one or more selected from the presence ratio of all Gram-negative bacteria in the bacterial flora, the presence ratio of individual Gram-negative bacteria, the types of Gram-negative bacteria, and the number of all or individual Gram-negative bacteria.

[0186] As a more preferred form, it is preferred that when the presence ratio of Gram-negative bacteria in the bacterial flora in the water system is equal to or higher than the specified value (for example, 10%), start or increase the use of the combined halogen compound, and / or when it does not correspond to being equal to or higher than the specified value (for example, 5%), terminate or reduce the use of the combined halogen compound.

[0187] As another more preferred form, it is preferred that when the number of bacteria in the water system is equal to or higher than the specified value (for example, 100 cfu / mL), make the combined halogen compound present (start or increase the use), and it is preferred that when it does not correspond to being equal to or higher than the specified value, terminate or reduce the use of the combined halogen compound.

[0188] 1-5. Application of the water system of the present embodiment

[0189] The water system to which the present embodiment is applied is not particularly limited. The present embodiment is preferably applied to a water system such as a water system in which treated water with suppressed endotoxin generation or reduced endotoxin concentration is expected to be produced. Furthermore, it can be applied to a water system that generates biological fouling, and it is also an advantage of the present embodiment to suppress biological fouling or inhibit biofilm formation in the water system. In addition, the compound or the agent containing the compound will also be referred to as an agent hereinafter.

[0190] The water system to which the present embodiment can be applied is not particularly limited. For example, it may include systems including various processes for water treatment, water treatment systems such as membrane treatment systems; circulating water systems (cooling water systems, boiler water systems) including cooling towers, boilers, etc.; circulating water systems such as pulp process water systems in pulp manufacturing or process water systems such as scrubber water systems, and one or more than two selected from these can be applied.

[0191] In a water treatment system or the like, the agent can be added to the water to be treated or the like for use, and it is preferably added immediately before membrane treatment or between membrane treatment and the treatment before it. In a circulating water system or the like, the agent can be added to circulating water, make-up water, or the like for use.

[0192] The place and method of adding the agent in the present embodiment are not particularly limited, and in the water system in use, it can be added at any part as an aqueous solution prepared at an arbitrary concentration. In addition, in the present embodiment, it can be applied to circulating water systems of heat exchangers in building air conditioners, general factories, petrochemical complexes, etc.

[0193] The operation method for making the bound halogen compound present in the present embodiment can be applied to a membrane device (preferably a reverse osmosis membrane device). The operation method can be suitably implemented by the membrane treatment method, biological fouling inhibition method, endotoxin generation inhibition method, endotoxin concentration reduction method, etc. The operation method of the present embodiment can be applied to the membrane treatment method, biological fouling inhibition method, endotoxin generation inhibition method, water system, device or system, etc. The operation method of the present embodiment can be applied to a water treatment system having at least a membrane treatment system (preferably a reverse osmosis membrane system).

[0194] The separation membrane used in this embodiment is not particularly limited. For example, ultrafiltration membranes (UF (ultrafiltration) membranes), microfiltration membranes (MF (microfiltration) membranes), nanofiltration membranes (NF (nanofiltration) membranes), reverse osmosis membranes (RO (reverse osmosis) membranes), etc. may be cited, and one or more than two of these may be selected. Among them, a reverse osmosis membrane is preferred. The reverse osmosis membrane (RO membrane) is not particularly limited. For example, membranes in the form of spiral, hollow fiber, flat film, etc. and made of substances such as cellulose acetate, aromatic polyamide, aromatic polyimide, etc. on the surface layer may be cited.

[0195] The water system including a reverse osmosis membrane device is not particularly limited. For example, water treatment water systems; circulating water systems such as cooling towers; process water systems such as pulp manufacturing, water use systems, or drainage recovery, etc. may be cited.

[0196] As an example of a water system including a reverse osmosis membrane device, it may also be arranged and include, in order or out of order: a coagulation treatment process, in which raw water flows in and a coagulant is injected into the raw water to cause turbidity, etc. to coagulate or flocculate; a solid-liquid separation process, in which the treated water containing the coagulated matter is separated into a precipitate and a supernatant; and a turbidity removal membrane treatment process, in which turbidity, etc. is further removed from the inflowing supernatant before reverse osmosis membrane treatment. In addition, for these treatment processes, treatment devices or treatment parts configured to perform the treatment processes separately may also be used.

[0197] As an example of a water system including a reverse osmosis membrane device, for example, refer to Figure 1 the water system 1 shown in the figure for description, but the water system related to this embodiment is not limited thereto. In the water system 1 including the reverse osmosis membrane device 2, it includes: a coagulation process performed by the coagulation treatment device 5, the coagulation treatment device 5 being configured to flow in raw water and inject a coagulant into the raw water to cause turbidity, etc. to coagulate or flocculate; a solid-liquid separation process performed by the solid-liquid separation device 4, the solid-liquid separation device 4 being configured to separate the treated water containing the coagulated matter into a precipitate and a supernatant; a pretreatment process performed by the filter 3, the filter 3 being configured to perform a turbidity removal membrane treatment for further removing turbidity, etc. from the inflowing supernatant before reverse osmosis membrane treatment; and a reverse osmosis membrane treatment process performed by the reverse osmosis membrane device 2, the reverse osmosis membrane device 2 being supplied with the treated water containing the combined halogen compound after pretreatment. In the reverse osmosis membrane treatment process, it can be separated into concentrated water and permeate water.

[0198] In the present embodiment, the compound (the bound halogen compound, halogen-based compound, or stabilizing compound) or a medicament containing these is preferably added in the pretreatment step, the reverse osmosis membrane step, or the steps prior thereto, and can be added to a pipe or a flow path that flows into the pretreatment step or the reverse osmosis membrane step, or can also be added between the pretreatment step and the reverse osmosis membrane step. Further, the compound or the like is preferably added downstream after the solid-liquid separation step.

[0199] In addition, as an example of a water system including a reverse osmosis membrane device, the following water treatment device (preferably an ultrapure water device) can be cited. The water treatment device includes: a raw water supply path configured to supply raw water; and a reverse osmosis membrane device configured to separate the raw water supplied from the raw water supply path into permeate water and concentrated water.

[0200] In addition, as an example of a water system including a reverse osmosis membrane device, the following water treatment device can be cited. The water treatment device includes: a raw water supply path configured to supply raw water; a filtration device and a filtration treatment water tank configured to filter the raw water supplied from the raw water supply path; and a filter device and a reverse osmosis membrane device configured to use the filtered water to be treated as a pretreatment for reverse osmosis membrane treatment. The turbidity removal membrane treatment can also be performed by the filter device.

[0201] 1-6. Each measurement method

[0202] <Calculation method of total residual chlorine concentration>

[0203] In the present embodiment, the total residual chlorine concentration is calculated based on the following method. In addition, Japanese Industrial Standards (JIS) K 0400-33-10:1999 can be referred to.

[0204] Total residual chlorine concentration = Free chlorine concentration + Activated bound chlorine concentration + Stabilized bound chlorine concentration.

[0205] Free chlorine concentration: The free chlorine concentration obtained by the N,N-diethyl-p-phenylenediamine (DPD) method (pocket residual chlorine meter, manufactured by HACH Company) [here, the free chlorine concentration obtained by the DPD method is the chlorine concentration measurement result (mg-Cl2 / L) 5 seconds to 30 seconds after using the free chlorine measurement reagent, i.e., DPD (Free) reagent].

[0206] Activated combined chlorine concentration: The value obtained by subtracting the measurement result of the free chlorine concentration (mg-Cl2 / L) from the chlorine concentration measurement result (mg-Cl2 / L) after 300 seconds obtained using the free chlorine measurement reagent, i.e., DPD (Free) reagent.

[0207] Stabilized combined chlorine concentration: The value obtained by subtracting the chlorine concentration measurement result (mg-Cl2 / L) after 300 seconds obtained using the free chlorine measurement reagent, i.e., DPD (Free) reagent, from the chlorine concentration measurement result (mg-Cl2 / L) after 180 seconds obtained using the total chlorine measurement reagent, i.e., DPD (Total) reagent.

[0208] Free chlorine ratio (%) = (Free chlorine concentration / Total residual chlorine concentration) × 100

[0209] Stabilized combined chlorine ratio (%) = (Stabilized combined chlorine concentration / Total residual chlorine concentration) × 100

[0210] In addition, the temperature of the test environment is set to 25°C.

[0211] <Measurement methods for pH value, TOC, and ORP>

[0212] The pH value (25°C) of the water system (such as the water to be treated and the circulating water) can be measured using a handheld pH meter manufactured by HORIBA. In addition, the TOC of the water system can be measured using a TOC meter. The ORP of the water system can be measured using an ORP meter.

[0213] <Measurement method for endotoxin concentration>

[0214] In this embodiment, the concentration of endotoxin in the water system or in water is measured and calculated based on the endotoxin test method: turbidimetry (the entire 17th revised edition of the Japanese Pharmacopoeia (General Test Methods) 4.01) (the entire 17th revised edition of the Japanese Pharmacopoeia (Notice No. 64 of the Ministry of Health, Labour and Welfare of Japan on March 7, 2016)).

[0215] <Analysis of the flora and types of bacteria>

[0216] In the present embodiment, for the analysis of the types of flora and bacteria, etc., amplicon sequencing data analysis (QIIME2) can be used. 16S rRNA gene amplicon sequencing analysis can be performed on samples collected in the water system, and based on the results of the analysis, the open-source analysis software QIIME2 can be used to calculate the presence ratio of each bacterium, the presence ratio of Gram-negative bacteria in the flora, etc. At this time, for example, it can also be set in the form of taxonomic bar plots (for example, https: / / view.qiime2.org). As the database used in the 16S rRNA gene amplicon sequencing analysis, the Silva database for bacteria can be used.

[0217] <Method for measuring the number of bacteria (cfu / mL)>

[0218] In the present embodiment, the number of bacteria (cfu / mL) in the water system or in water can be measured and calculated based on the method for measuring the number of bacteria using the dilution agar medium method (cultivation: temperature 30 °C, 3 days). In addition, CFU is an abbreviation for Colony forming unit, which is a unit representing the number of viable bacteria (the number of living bacteria).

[0219] 2. Method for inhibiting endotoxin production of the present invention

[0220] In the description of the method and the like of the present embodiment, it is appropriate to omit the description of each structure or each treatment method such as biofouling inhibition, endotoxin production inhibition, and chemicals that are repeated with the above-mentioned "1." and the following "3.", etc. The descriptions of the above-mentioned "1." and "3." etc. are also applicable to the present embodiment and can be appropriately adopted.

[0221] The present embodiment can provide a method for inhibiting endotoxin production or reducing endotoxin concentration in a water system, a method for producing treated water with a reduced endotoxin concentration, in which a bound halogen compound generated by at least using a halogen-based compound and a stabilized amino compound or a bound halogen compound with a molecular weight of 60 or more is present in the water system. Preferably, the bound halogen compound is present or applied to a water system in which Gram-negative bacteria are present.

[0222] Preferably, a chemical agent containing a bound halogen compound generated by at least using a halogen-based compound and a stabilized amino compound or a bound halogen compound with a molecular weight of 60 or more is added to the water system.

[0223] The bound halogen compound is preferably a bound halogen compound generated by at least using a halogen-based compound and / or a stabilized compound in a water system containing a halogen-based compound or an amino compound derived from raw water or from a process.

[0224] Preferably, the total halogen concentration in the water system is adjusted to 0.01 mg / L to 100 mg / L.

[0225] The combined halogen compound is preferably a combined halogen compound formed by adjusting the molar ratio of the halogen compound to the stabilizing compound (stabilizing compound / halogen compound) to 1.0 or more.

[0226] When the presence ratio of Gram-negative bacteria in the flora in the water system is equal to or higher than a specified value, it is preferable to make the compound present in the water system. More preferably, the specified value is in the range of 60% to 10%, and thus it is preferable to make the combined halogen compound present or control it.

[0227] When the number of bacteria in the water system is equal to or higher than a specified value, it is preferable to make the compound present in the water system. More preferably, the specified value is in the range of 1,000 cfu / mL to 10 cfu / mL, and thus it is preferable to make the combined halogen compound present or control it.

[0228] In addition, the combined halogen compound used in the present embodiment has, for example, a biofouling inhibition effect, a biofilm inhibition effect, an endotoxin generation inhibition effect, an endotoxin concentration reduction effect, a Gram-negative bacteria proliferation inhibition effect, a presence ratio inhibition effect of Gram-negative bacteria in the flora, etc., and preferably exhibits the above effects in the water system. Therefore, the combined halogen compound can be contained in a biofouling inhibitor, a biofilm inhibitor, an endotoxin generation inhibitor, an endotoxin concentration reducer, a Gram-negative bacteria proliferation inhibitor, a presence ratio inhibitor of Gram-negative bacteria in the flora, etc., or the combined halogen compound can be used in these agents. In addition, for example, a biofouling inhibitor for inhibiting endotoxin generation, an endotoxin generation inhibitor accompanied by biofouling inhibition, etc. can be cited. In the present embodiment, the combined halogen compound itself can be used as the agent in the present embodiment, the combined halogen compound can be used in combination with other components, or a multi-formulation agent combination of an agent containing the combined halogen compound and an agent of other components can be prepared and mixed for use when in use. In addition, when other agents, such as a slime inhibitor or a biofouling inhibitor (preferably an organic agent), are used in the water system, the agent in the present embodiment is expected to have an effect such as the endotoxin generation inhibition effect, and is preferably used continuously or intermittently, more preferably intermittently. In addition, in order to generate the combined halogen compound, a multi-formulation agent combination or a combined product containing a first agent containing a halogen compound and a second agent containing a stabilizing compound can be prepared and mixed for use when in use.

[0229] In the present embodiment, there may also be provided the bound halogen compound or its use for achieving the purposes such as the inhibition of biological fouling, the inhibition of biofilm formation, the inhibition of endotoxin generation, the reduction of endotoxin concentration, the inhibition of the proliferation of Gram-negative bacteria, and the inhibition of the ratio of Gram-negative bacteria in the flora. In addition, in the present embodiment, the bound halogen compound may also be used for manufacturing agents or preparations such as the biological fouling inhibitor. In addition, in the present embodiment, there may also be provided a method for biological fouling inhibition and the like using the bound halogen compound.

[0230] 3. Another embodiment of the present invention

[0231] In the description of the method of the present embodiment, the present technology, etc., the description of each structure or each treatment method, each technical feature, etc. of biological fouling inhibition, endotoxin generation inhibition, agents, etc., which are repeated with the content described in the above "1.", "2.", and the following content, etc., is preferably omitted. The descriptions of the above "1.", "2.", etc. are also applicable to the present embodiment and can be appropriately adopted.

[0232] In the system for membrane treatment, biological fouling inhibition, endotoxin concentration reduction, etc. of the present embodiment, it is preferably to include a management device for membrane treatment, biological fouling inhibition, endotoxin concentration reduction, etc. that at least includes a control unit. The management control system for membrane treatment, biological fouling inhibition, endotoxin concentration reduction, etc. of the present embodiment may also be further provided with a communication unit, and the communication unit can enable the control unit or the management device for membrane treatment, biological fouling inhibition, endotoxin concentration reduction, etc. including the control unit to perform signal transmission and reception with other parts or other devices wirelessly and / or wiredly.

[0233] In addition, the method related to this embodiment can also be implemented by a device including a central processing unit (CPU), etc., in a device (such as a computer, a programmable logic controller (PLC), a server, a cloud service, etc.) for managing membrane treatment conditions, biofouling conditions, endotoxin concentration conditions, etc., or a control unit. Additionally, the method related to this embodiment can be saved as a program in a hardware resource including a recording medium (such as a non-volatile memory (Universal Serial Bus (USB) memory, etc.), a solid state drive (SSD), a hard disk drive (HDD), a compact disc (CD), a digital video disc (DVD), a Blu-ray Disc, etc.), and can be implemented by the control unit. A management system for green liquor treatment conditions, etc., which is controlled by the control unit to add a specified amount of chemical agent to the crude green liquor, and a device including the control unit or the system can also be provided. Additionally, the management device may also include an input unit such as a keyboard, a communication unit such as a network, a display unit such as a display, etc.

[0234] A device or management system for managing membrane treatment conditions, biofouling conditions, endotoxin concentration conditions, etc. may include: an input unit such as a keyboard, a communication unit such as a network, an output unit such as a display, a storage unit such as an HDD, the measurement unit, a chemical agent addition unit, etc. The device or system preferably includes an input unit, an output unit, and a storage unit, and further preferably includes a communication unit and / or a measurement unit. Additionally, it preferably includes a chemical agent addition unit.

[0235] In the input unit, user operations can be accepted by an operator who executes the method of this embodiment. The input unit may include, for example, a mouse and / or a keyboard, etc. Additionally, the display surface of the display device can also be configured as an input unit that accepts touch operations.

[0236] The output unit can output membrane treatment conditions, biofouling conditions, endotoxin concentration conditions, etc., and information related thereto (such as tables, graphs, explanatory texts, etc.). Examples of the output unit include a display device that displays images, a speaker that outputs sounds, a printing device that prints on a printing medium such as paper, etc., but are not limited to these.

[0237] The storage unit can store data input by the operator and data set for observing the green liquor treatment conditions. The storage unit may include, for example, a recording medium.

[0238] In addition, a management system for performing membrane treatment, biological fouling inhibition, endotoxin generation inhibition, etc. of the present embodiment can be implemented by using programs and hardware. Although not limited thereto, one embodiment (not shown) of the computer 1 in one embodiment of the present embodiment includes at least a CPU as a component of the computer 1, and further may include one or two selected from a random access memory (RAM), a storage unit, an output unit, an input unit, a communication unit, a read only memory (ROM), and a measurement unit, etc. Preferably, it includes the RAM, the storage unit, the output unit, and the input unit among them, and further preferably includes at least one of the communication unit, the measurement unit, the ROM, etc. Each component is preferably connected by a bus as a data transmission path, for example.

[0239] In addition, the present technology can also adopt the following structures or technical features.

[0240] · [1] A membrane treatment method, a biological fouling inhibition method, or an endotoxin generation inhibition method, in which a combined halogen compound generated by using at least a halogen-based compound and a stabilizing compound (preferably a stabilized amino compound) or a medicament containing the compound, or a combined halogen compound having a molecular weight of 60 or more (for example, a molecular weight of 1000 or less or 500 or less) or a medicament containing the compound is present in a water system in which Gram-negative bacteria are present.

[0241] · [2] The method according to [1] above, wherein a medicament containing a combined halogen compound generated by using at least a halogen-based compound and a stabilizing compound (preferably a stabilized amino compound) or a combined halogen compound having a molecular weight of 60 or more is added to the water system. The combined halogen compound is preferably at least one of a chlorine-based aminosulfonic acid compound and a bromine-based aminosulfonic acid compound.

[0242] · [3] The method according to [1] or [2] above, wherein the combined halogen compound is a combined halogen compound generated by using at least a halogen-based compound and / or a stabilizing compound.

[0243] · [4] The method according to any one of [1] to [3] above, wherein the combined halogen compound is a combined halogen compound generated by using a halogen-based compound and / or a stabilizing compound in a water system containing a halogen-based compound or an amino compound derived from raw water or a process.

[0244] · [5] The method according to any one of [1] to [4] above, wherein the total halogen concentration in the water system is adjusted to 0.01 mg / L to 100 mg / L.

[0245] [6] The method according to any one of [1] to [5], wherein the bound halogen compound is a bound halogen compound produced by adjusting the molar ratio of the halogen compound to the stabilizing compound (stabilizing compound / halogen compound) to 1.0 or more.

[0246] [7] A method according to any one of [1] to [6], wherein the bound halogen compound is allowed to exist when the ratio of Gram-negative bacteria in the flora in the water system is greater than a prescribed value, and the prescribed value is in the range of 60% to 10%.

[0247] [8] The method according to any one of [1] to [7], wherein the bound halogen compound is allowed to exist when the bacterial count in the water system is greater than or equal to a predetermined value, wherein the predetermined value is within a range of 1,000 cfu / mL to 10 cfu / mL.

[0248] [9] A method according to any one of [1] to [8], wherein the water system uses at least one of the Gram-negative bacteria of the genus Pseudomonas, Cupricobacterium, Methylotrophic Bacteria, Sphingomyelinum, Rhizobium, Neosphingobacterium, Xanthomonas, Bird's-eye Bacteria, Neochlamydia, Legionnaires' Disease Bacteria, Vermiphilaceae, Sphingomonas, Phenylbacterium, Cytomegalovirus, Bradyrhizobium, and Filamentobacterium as an indicator, and in the presence of the indicator, the bound halogen compound is allowed to exist.

[0249]

[10] The method according to any one of [1] to [9], wherein the water system uses Pseudomonas and / or Cupriavidus as indicators, and the bound halogen compound is allowed to exist in the presence of the indicators.

[0250]

[11] The method according to any one of [1] to

[10] , wherein the bound halogen compound is used to suppress the generation of endotoxin in the water system.

[0251]

[12] The method according to any one of [1] to

[11] , wherein the water system is a water system including a water treatment device including a membrane treatment device.

[0252]

[13] The method according to any one of [1] to

[12] , wherein treated water in which endotoxin production is suppressed or endotoxin concentration is reduced is obtained.

[0253] ·

[14] An endotoxin production inhibitor or endotoxin concentration reducer, containing a bound halogen compound with a molecular weight of 60 or more, or a bound halogen compound formed by using at least a halogen-based compound and / or a stabilizing compound. An endotoxin production inhibitor combination product or a combination product for an endotoxin concentration reducer, comprising a first agent containing a halogen-based compound and a second agent containing a stabilizing compound. The combination product in this specification can be a kit product or a set product. Additionally, the agent in this specification can also be a composition, for example, a composition for inhibiting endotoxin production or reducing endotoxin concentration.

[0254] ·

[15] A water treatment agent containing at least either a halogen-based compound or a stabilizing compound, and when used for inhibiting endotoxin production or reducing endotoxin concentration in a water system, it is used in combination with a halogen-based compound and a stabilizing compound. Additionally, the agent can also be a water treatment composition.

[0255] ·

[16] A bound halogen compound with a molecular weight of 60 or more, or a bound halogen compound formed by using at least a halogen-based compound and / or a stabilizing compound, or its use, which is present in the agent or combination product described in the above

[14] or

[15] , or in the manufacture of an endotoxin production inhibitor or an endotoxin concentration reducer, or an endotoxin production inhibitor combination product or an endotoxin concentration reducer combination product, or is used for manufacturing these.

[0256] ·

[17] A bound halogen compound with a molecular weight of 60 or more, or a bound halogen compound formed by using at least a halogen-based compound and / or a stabilizing compound, or its use, for inhibiting endotoxin production or reducing endotoxin concentration.

[0257] ·

[18] A water treatment method using the agent, composition, product, or compound described in any one of the above

[14] to

[17] .

[0258] Examples

[0259] The following examples and comparative examples are listed to illustrate the embodiments of the present invention. In addition, the scope of the present invention is not limited to the examples.

[0260] [Example 1]

[0261] <Experimental conditions>

[0262] Water was passed through an acrylic unit [membrane fouling simulator (MFS) (Non-Patent Document 3)] sandwiching an RO membrane (a polyamide-based RO membrane ES20, 20 cm × 2 cm, manufactured by Nitto Denko Corporation) and a spacer at a rate of 100 mL / min, and dechlorinated tap water (raw water) containing IPA (isopropyl alcohol: 0.7 mg / L in terms of TOC) and sodium phosphate (0.02 mg / L in terms of P) as nutrient sources was added. A slime control agent was added at a concentration that could inhibit the differential pressure rise of more than 80% of the units compared to the control (without adding the agent), and the endotoxin concentration at the outlet of the MFS unit at this time was analyzed (see Figure 2 ). In addition, the endotoxin concentration, total chlorine concentration (total residual chlorine concentration), etc. in [Example 1] and [Example 2] were measured according to the above-mentioned "1-6. Each measurement method".

[0263] In addition, Figure 2 There are 21 series of MFS in

[0264] Series 1 to 3 were not added (control), Series 4 to 6 were "chloramine", Series 7 to 9 were DBNPA, Series 10 to 12 were Cl-MIT, Series 13 to 15 were chloramine sulfonic acid, Series 16 to 18 were chloramine sulfonic acid + Cl-MIT, and Series 19 to 21 were not implemented.

[0265] The water to be treated was pressurized by a pump and supplied to the MFS as feed water (water volume: 100 mL / min, water pressure: 0.2 MPa, water temperature: 25°C) for RO membrane treatment. In addition, compared with the MFS used in [Example 1], the flow rate was 100 mL / min per unit. The pH value of the water to be treated was 5 to 9.

[0266] <Preparation of the agent containing sodium monochloramine sulfonate>

[0267] The agent containing sodium monochloramine sulfonate prepared by the following method was used as the chloramine sulfonic acid in [Example 1] and [Example 2]. At this time, the molar ratio of (stabilizing compound / chlorine-based compound) was 1.57.

[0268] An aqueous sodium hydroxide solution was prepared using pure water such that sodium hydroxide (manufactured by KISHIDA CHEMICAL CO., LTD.) was 48% by mass. After mixing 19.5 g of the pre-prepared aqueous sodium hydroxide solution with 7.5 g of pure water, 15.0 g of amidosulfuric acid (sulfamic acid) (manufactured by KISHIDA CHEMICAL CO., LTD.) was added and mixed. Thereafter, 58.0 g of sodium hypochlorite (manufactured by Asahi Glass Co., Ltd.) with an available chlorine concentration of 12% by mass was further added and mixed to prepare a monochloramine sulfonic acid reagent. In addition, the total chlorine concentration of this agent was 7% by mass in terms of Cl2.

[0269] <Chloramine Reagents Containing Ammonium Salts and Chlorine>

[0270] A solution prepared by adding and mixing 0.38 g of ammonium sulfate (manufactured by KISHIDA CHEMICAL CO., LTD.) into 10 L of pure water and a solution prepared by adding and mixing 3.48 g of an aqueous sodium hypochlorite solution with an available chlorine concentration of 12% by mass (manufactured by Asahi Glass Co., Ltd.) into 10 L of pure water were separately prepared. They were added to a test water system (water flow rate: 300 mL) in an addition amount of 0.1 mL each and mixed using a static mixer, thereby forming chloramine in the system.

[0271] <Mixture Reagent of Cl-MIT and MIT>

[0272] As a mixture reagent of 5-chloro-2-methyl-4-isothiazolin-3-one (Cl-MIT) and 2-methyl-4-isothiazolin-3-one (MIT), "KATHON WT" manufactured by DOW CHEMICAL COMPANY (Japan) Limited was used. In addition, this reagent contained approximately 10.4% by mass of Cl-MIT and approximately 3.5% by mass of MIT.

[0273] <DBNPA Reagent>

[0274] DBNPA: 2,2-dibromo-3-nitrilopropionamide

[0275] Reactant A: A substance obtained by mixing an aqueous ammonium bromide solution and an aqueous sodium hypochlorite solution.

[0276] The test results using the MFS test device showed that compared with the cases of single treatment with chloramine, DBNPA (2,2-dibromo-3-nitrilopropionamide), and Cl-MIT (5-chloro-2-methyl-4-isothiazolin-3-one), the endotoxin concentration could be inhibited to 50% or less in the case of single treatment with monochloramine sulfonic acid. In addition, in the alternate treatment with monochloramine sulfonic acid + Cl-MIT, the endotoxin concentration could also be significantly inhibited. The endotoxin concentration of the control was 201 EU / mL.

[0277] [Table 1]

[0278] Table 1

[0279]

[0280] In addition, the addition concentration of chloramine and chloraminesulfonic acid in mg / L is "mg-Cl2 / L" (calculated based on the total chlorine concentration).

[0281] [Example 2] Occupancy rate of Gram-negative bacteria in the RO membrane

[0282] The <Experimental conditions> of Example 2 are the same as those of Example 1. Regarding the chemicals and the addition period, they are as described below. The measurement of the bacterial flora in the RO membrane is carried out as follows.

[0283] Test Example 2-1: Control: No chemical added (endotoxin concentration 201 EU / mL)

[0284] Test Example 2-2: Continuously add 1.2 mg / L of Cl-MIT

[0285] Test Example 2-3: Continuously add 5.2 mg-Cl2 / L of chloraminesulfonic acid

[0286] <Sampling of fouling substances>

[0287] 1) Remove the RO membrane and the water supply gasket from the device.

[0288] 2) Cut the water supply gasket and the RO membrane into strips 1 cm to 2 cm wide together with the attached biofilm, and place them in a sterilized 50 mL centrifuge tube.

[0289] 3) Place zirconia balls and 30 ml of pure water in the centrifuge tube.

[0290] 4) Cover the lid and stir well using a vortex to separate the biofilm from the water supply gasket and the RO membrane.

[0291] 5) Use clean forceps to remove the water supply gasket and the RO membrane. In addition, if there is biofilm attached to the water supply gasket and the RO membrane, shake off the biofilm in 10 mL of separately prepared pure water (PW).

[0292] 6) After completely removing the water supply gasket and the RO membrane, put the 10 mL of PW from step "5)" into the centrifuge tube.

[0293] 7) Perform centrifugation at 12,000 rpm for 10 minutes.

[0294] 8) For the sample after discarding the supernatant, 16S rRNA amplicon analysis was performed using the following <Measurement Device and Analysis> to measure the proportions of various types of bacterial flora and Gram-negative bacteria. In addition, QIIME: Blast analysis of the output operational taxonomic units (OTUs); preparation of amplicons after DNA extraction; change of the sequence to be analyzed (400 bp - less than 500 bp).

[0295] · Run at 2 bp × 300 bp paired ends by MiSeq. · Data sorting based on Multiplex Identifier (MID) tags. · Preparation of microbial community composition and heat map using QIIME with the acquired data. · Extract DNA from the sample and prepare an amplicon library. · Perform homology search based on Blast for each OTU output by QIIME.

[0296] <Measurement Device and Analysis>

[0297] Device: MiSeq(R) system (next-generation sequencer)

[0298] For the analysis results, calculate the microbial community analysis results using Qiime2.

[0299] Analysis software: Qiime2 / Algorithm: DADA / Database: SILVA

[0300] Using the MFS test device, collect the biofilm attached to the RO membrane surface in the MFS after performing a water flow test using MFS under the <Experimental Conditions> and perform microbial community analysis.

[0301] [Table 2]

[0302] Table 2 Test Example 2-1 Test Example 2-2 Test Example 2-3 Control Cl-MIT Chloramine sulfonic acid Gram-negative bacteria Cupriavidus 26.3 30.2 4.6 Pseudomonas 42.1 61.4 4.8 Ralstonia 4.3 1.3 0.3 Acidovorax 5.5 - 0.1 Azotobacter 3.0 4.8 0.4 Others 6.6 1.1 6.5 Gram-positive bacteria 3.1 - 75.1 Unknown 9.1 1.2 8.2 Total (100%) 100 100 100 Gram-negative bacteria (%) 87.8 98.8 16.7 (Negative bacteria / [Negative bacteria + Positive bacteria]) (%) 96.6 100.0 18.2

[0303] As a result, as Figure 2As shown in Table 2, in the case of the control without the addition of drugs and the treatment with Cl-MIT alone, Pseudomonas bacteria or Cupriavidus bacteria, which are Gram-negative bacteria, are dominant, while in the case of the treatment with ClSul alone, Mycobacterial bacteria and Mycobacterium bacteria, which are Gram-positive bacteria, are dominant. The above situation shows that the difference in endotoxin concentration is caused by the difference in the flora of the biofilm caused by the applied slime inhibitor. In addition, since the number of bacteria in the raw water is 2.2×10⁵ cfu / mL, chloramine sulfonic acid is present in the water system, and the number of bacteria in the water system (preferably the total number of Gram-negative bacteria) is made to be 1,000 cfu / mL to less than 10 cfu / mL, whereby the number of Gram-negative bacteria in the water system can be significantly inhibited, and thus the generation or concentration reduction of endotoxin in the water system can be inhibited.

[0304] [Example 3]

[0305] <Experimental conditions>

[0306] The dechlorinated tap water (raw water) added with citric acid (0.7 mg / L in terms of TOC), ammonium chloride (0.6 mg / L in terms of N), and sodium phosphate (0.02 mg / L in terms of P) as nutrient sources was heated to 35 °C using a water heater, and the tap water (raw water) was passed through an acrylic unit [MFS (Non-Patent Document 3)] sandwiching an RO membrane (polyamide-based RO membrane ES20, size 20 cm × 2 cm, manufactured by Nitto Denko Corporation) and gaskets at a rate of 100 mL / min, and a slime control agent was added at a concentration that can inhibit the differential pressure rise of more than 80% of the units compared to the control (without the addition of drugs), and the endotoxin concentration at the outlet of the MFS unit at this time was analyzed (refer to Figure 4 ). The conditions of the treated water (feed water) at this time (for example, water volume, water pressure, temperature, pH value, RO membrane treatment conditions, etc.) are the same as those in Example 1. In addition, the endotoxin concentration, total chlorine concentration (total residual chlorine concentration), etc. are measured in accordance with the above-mentioned "1-6. Each measurement method".

[0307] In addition, Figure 4 There are 3 series of MFS in

[0308] Series 1 is not added (control), Series 2 is a chlorine-based aminosulfonic acid compound, and Series 3 is a bromine-based aminosulfonic acid compound. The chlorine-based aminosulfonic acid compound is the same as the compounds used in Example 1 and Example 2, and the bromine-based aminosulfonic acid compound is a compound manufactured by the following method. In addition, Table 1 in Example 1 is the measurement result of the endotoxin concentration 32 days after the start of the test, and Table 3 in Example 3 is the measurement result of the endotoxin concentration 10 days after the start of the test.

[0309] <Preparation of Bromine-based Amidosulfonic Acid Compounds>

[0310] Use the agent prepared by the following method as the bromine-based amidosulfonic acid compound in [Example 3]. At this time, the molar ratio of (stabilized compound / bromine-based compound) is 1.08.

[0311] Under a nitrogen atmosphere, add 12.9 g of sodium hydroxide to 51.9 g of water and stir well. Then, while cooling, mix 10.7 g of amidosulfonic acid, 16.3 g of liquid bromine, 8.2 g of potassium hydroxide, and 51.9 g of water to prepare a composition. The pH value of the composition is 14, and the effective halogen concentration (effective chlorine conversion concentration) of the composition is 7% by mass in terms of Cl2.

[0312] [Table 3]

[0313]

[0314] The test results using the MFS test device show that compared with the raw water and the control, chloramine sulfonic acid and bromamine sulfonic acid can suppress the discharge amount of endotoxin to a low level. In addition, the differential pressure inhibition effect and the endotoxin concentration of chloramine sulfonic acid and bromamine sulfonic acid are at the same level.

[0315] The endotoxin concentration of the raw water used in Example 3 is 283 EU / mL.

[0316] The test results using the MFS test device show that compared with the raw water and the control, chloramine sulfonic acid and bromamine sulfonic acid in Example 3 can suppress the discharge amount of endotoxin to a low level. In addition, the differential pressure inhibition effect and the endotoxin concentration inhibition effect of chloramine sulfonic acid and bromamine sulfonic acid are at the same level. Based on this, it is considered that the bromine-based amidosulfonic acid compound, like the chlorine-based amidosulfonic acid compound, has the effect of reducing the proliferation or the number of bacteria such as Gram-negative bacteria that produce endotoxin.

[0317] Therefore, it is considered that by making a bound halogen compound (preferably a bound chlorine-based compound and / or a bound bromine-based compound) present in the water system, the absolute amount of Gram-negative bacteria present in the water system decreases, and the bacterial flora of the bacteria attached to the inside of the water system also changes (bacteria that are difficult to discharge endotoxin are dominant). As a method of making a bound halogen compound present in the water system, it is possible to consider adding a bound halogen compound, or adding a halogen-based compound and / or a stabilized compound to the water system in such a way that a bound halogen compound is generated in the water system. It is considered that the endotoxin concentration can be reduced and biological fouling can be suppressed thereby.

[0318] Explanation of Reference Numerals in the Drawings

[0319] 1: Water system

[0320] 2: Reverse osmosis membrane device

[0321] 3: Filter

[0322] 4: Solid-liquid separation device

[0323] 5: Condensation device

[0324] 10: First chemical addition device; Second chemical addition device

Claims

1. A membrane treatment method or a method for inhibiting biological fouling, in which a bound halogen compound formed by using a halogen-based compound and an amino compound as a stabilizing compound is present in a water system in which Gram-negative bacteria are present.

2. The membrane treatment method or biofouling inhibition method according to claim 1, wherein, Add a medicament containing a bound halogen compound formed by using a halogen-based compound and an amino compound as a stabilizing compound to the water system.

3. The membrane treatment method or biofouling inhibition method according to claim 1 or 2, wherein, The bound halogen compound is a bound halogen compound formed by using a halogen-based compound and / or a stabilizing compound in a water system containing a halogen-based compound or an amino compound derived from raw water or a process.

4. The membrane treatment method or biofouling inhibition method according to claim 1 or 2, wherein, Adjust the total halogen concentration in the water system to 0.01 mg / L to 100 mg / L.

5. The membrane treatment method or biofouling inhibition method according to claim 1 or 2, wherein, The bound halogen compound is a bound halogen compound formed by adjusting the molar ratio (stabilizing compound / halogen-based compound) of the halogen-based compound and the stabilizing compound to 1.0 or more.

6. The membrane treatment method or biological fouling inhibition method according to claim 1 or 2, wherein, The bound halogen compound is present based on the presence ratio of Gram-negative bacteria in the flora of the water system and / or the number of bacteria in the water system.

7. The membrane treatment method or biofouling inhibition method according to claim 1 or 2, wherein When the presence ratio of Gram-negative bacteria in the flora of the water system is equal to or higher than a specified value, the bound halogen compound is present in the water system, and the specified value is set within the range of 60% to 10%.

8. The membrane treatment method or biofouling inhibition method according to claim 1 or 2, wherein, When the number of bacteria in the water system is equal to or higher than a specified value, the bound halogen compound is present in the water system, and the specified value is set within the range of 1,000 cfu / mL to 10 cfu / mL.

9. The membrane treatment method or biological fouling inhibition method according to claim 1 or 2, wherein, The water system uses at least one of Gram-negative bacteria such as bacteria of the genus Pseudomonas, Cupriavidus, Methyloversatilis, Sphingopyxis, Rhizobacter, Novosphingobium, Xanthobacteraceae, Berkiella, Neochlamydia, Legionella, Vermiphilaceae, Sphingomonas, Phenylobacterium, Nannocystis, Bradyrhizobium, and Hyphomicrobium as an index, and when the index is present, the bound halogen compound is present.

10. The membrane treatment method or biofouling inhibition method according to claim 1 or 2, wherein, The water system uses bacteria of the genus Pseudomonas and / or Cupriavidus as an index, and when the index is present, the bound halogen compound is present.

11. The membrane treatment method or biological fouling inhibition method according to claim 1 or 2, wherein, Use the bound halogen compound to inhibit the generation of endotoxin in the water system.

12. The membrane treatment method or biological fouling inhibition method according to claim 1 or 2, wherein, The water system is a water system including a water treatment system including a membrane treatment device.

13. A method for inhibiting endotoxin generation in a water system, wherein a bound halogen compound formed by using at least a halogen-based compound and an amino compound as a stabilizing compound is present in the water system.

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