Concentration device and concentration method

Abstract

To provide a concentrator and a concentration method, which easily maintain microorganism recovery efficiency while removing impurities in a negative charge membrane method.SOLUTION: A concentrator 100 includes: a negative charge membrane 102 that has a hole with a first bore diameter and that is negatively charged; a water sample supply part 106 that is arranged on the upstream side of the negative charge membrane 102 and that supplies a water sample; and a preliminary membrane 103 that is arranged on a channel between the negative charge membranes 102 from the water sample supply part 106 and that has a hole with a second bore diameter.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a concentrating device and a concentrating method. [Background technology]

[0002] Conventionally, the negative charge membrane method has been known as a processing method for detecting viruses in water. For example, Patent Document 1 describes a method in which a purified virus liquid is prepared from a sample liquid such as environmental water (e.g., river water, lake water, seawater, rainwater, etc.), drinking water (e.g., well water, tap water, bottled water, etc.), industrial water (e.g., sewage, drainage, pool water, agricultural water, industrial water, refrigerant water, etc.), the prepared purified virus liquid is concentrated by the negative charge membrane method or the like, nucleic acid is extracted, and the virus is detected.

[0003] Also, in the past, when the sample water to be filtered contains impurities, a method has been known in which a prefilter having a larger pore size than the filter for the intended filtration is placed upstream of the filter to perform prefiltration and prevent clogging of the filtration membrane. For example, Patent Document 2 describes a method of preventing clogging of the downstream filter by first removing impurities using a prefilter having a larger pore size, and then filtering with the downstream filter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-195756 A [Patent Document 2] JP 2013-039047 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when prefiltration is performed in the negative membrane method, the virus recovery efficiency by the negative membrane method may be reduced. For example, the virus to be recovered may be captured in a prefilter arranged upstream of the negative membrane, resulting in a decrease in the virus captured by the negative membrane, and as a result, the virus recovery efficiency may be reduced.

[0006] An object of the present disclosure is to provide a concentrating device and a concentrating method that can easily maintain the recovery efficiency of microorganisms while removing contaminants in a negatively charged membrane method. [Means for solving the problem]

[0007] A concentrating device according to some embodiments includes a negatively charged membrane having pores of a first pore size, a sample water supply unit arranged upstream of the negatively charged membrane and supplying sample water, and a spare membrane arranged on a flow path between the sample water supply unit and the negatively charged membrane and having pores of a second pore size. In such a concentrating device, the spare membrane functions as a pre-filtration filter that removes impurities contained in the sample water. Therefore, according to the concentrating device, it is possible to maintain the recovery efficiency of microorganisms with the negatively charged membrane while removing impurities by pre-filtration with the spare membrane.

[0008] In one embodiment, the second pore size is a pore size that allows microorganisms to pass through, which prevents microorganisms from being captured in the preliminary membrane and maintains the efficiency of collecting microorganisms in the negatively charged membrane.

[0009] In one embodiment, the concentrating device further includes a mixed solution storage tank for storing a mixed solution to be mixed with the sample water, and a mixed solution supply pipe that joins the flow path upstream of the negative charge membrane and downstream of the spare membrane and supplies the mixed solution from the mixed solution storage tank. This prevents microorganisms from being adsorbed by ions contained in the mixed solution to form positively charged complexes, which are then captured by the negative charge that the spare membrane may have, thereby preventing a decrease in the recovery efficiency of microorganisms by the concentrating device.

[0010] In one embodiment, the concentrating device further includes an acidic solution storage tank for storing an acidic solution, an acidic solution supply pipe that joins the flow path downstream of the junction of the flow path and the mixed solution supply pipe and upstream of the negative charge membrane, and supplies the acidic solution from the acidic solution storage tank, an alkaline solution storage tank for storing an alkaline solution, and an alkaline solution supply pipe that joins the flow path downstream of the junction of the flow path and the mixed solution supply pipe and upstream of the negative charge membrane, and supplies the alkaline solution from the alkaline solution storage tank. This allows the concentrating device to perform acid washing and alkaline extraction processes to recover a concentrated solution of microorganisms.

[0011] In one embodiment, the second pore size is smaller than the first pore size, which allows smaller impurities to be removed from the preliminary membrane, thereby further suppressing clogging of the negatively charged membrane.

[0012] In one embodiment, the concentration device further includes a notification unit that notifies the user that the filtration resistance of the preliminary membrane has reached a predetermined threshold value or more when the filtration resistance of the preliminary membrane has reached a predetermined threshold value or more, thereby preventing clogging of the preliminary membrane and preventing problems such as a decrease in the processing performance of the concentration device.

[0013] A concentration method according to some embodiments includes a negatively charged membrane having pores of a first pore size, a sample water supply unit arranged upstream of the negatively charged membrane and supplying sample water, a spare membrane arranged on a flow path between the sample water supply unit and the negatively charged membrane and having pores of a second pore size, a mixed solution storage tank for storing a mixed solution to be mixed with the sample water, a mixed solution supply pipe that joins the flow path upstream of the negatively charged membrane and downstream of the spare membrane and supplies the mixed solution from the mixed solution storage tank, an acidic solution storage tank for storing an acidic solution, and an acidic solution supply tank that joins the flow path downstream of a junction of the flow path and the mixed solution supply pipe and upstream of the negatively charged membrane and supplies the acidic solution from the acidic solution storage tank. A concentration method performed by a concentration device including a supply pipe, an alkaline solution storage tank for storing an alkaline solution, and an alkaline solution supply pipe that joins the flow path downstream of the joining point of the flow path and the mixed solution supply pipe and upstream of the negatively charged membrane to supply the alkaline solution from the alkaline solution storage tank, the concentration method including a first step of supplying the sample water from the sample water supply unit to the negatively charged membrane and supplying the mixed solution from the mixed solution storage tank to mix the mixed solution with the sample water, a second step of supplying the acidic solution from the acidic solution storage tank to the negatively charged membrane, and a third step of supplying the alkaline solution from the alkaline solution storage tank to the negatively charged membrane. In this concentration method, the preliminary membrane functions as a pre-filtration filter that removes impurities contained in the sample water. Therefore, according to this concentration method, it is possible to maintain the recovery efficiency of microorganisms with the negatively charged membrane while removing impurities by pre-filtration with the preliminary membrane. Effect of the Invention

[0014] According to the present disclosure, it is possible to provide a concentrating device and a concentrating method that can easily maintain the recovery efficiency of microorganisms while removing contaminants in a negatively charged membrane method. [Brief description of the drawings]

[0015] [Figure 1]FIG. 1 is a schematic diagram of a concentrating device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram for explaining a first step of the treatment of the negative charge membrane method performed by the concentrating device of FIG. [Diagram 3] 3 is a schematic diagram for explaining a second step of the treatment of the negative charge membrane method performed by the concentrating device of FIG. 2. FIG. [Figure 4] 3 is a schematic diagram for explaining a third step of the treatment of the negative charge membrane method performed by the concentrating device of FIG. 1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] For example, prefiltration may be performed by placing a prefilter with a larger pore size than the filter intended for filtration upstream of the filter in question, in which case multiple filters are placed in the flow path, for example, by using multiple filter cartridges, stacking membrane filters, or stacking prefiltration layers.

[0018] For example, in the invention described in Patent Document 2, a pre-filter is provided upstream of the filter. The filter in the pre-filter has coarser pores than the filter in the filter, and is configured to be able to capture and remove plant debris. This is expected to reduce the frequency of clogging of the filter in the filter and improve the economic efficiency of the system as a whole.

[0019] However, when pre-filtration is performed in the negative membrane method, the recovery efficiency of viruses by the negative membrane method may be reduced. The negative membrane method is a process performed for the purpose of recovering a concentrated solution in which the virus concentration is increased by concentrating the viruses from the sample water. Microorganisms including bacteria and viruses have the property of being negatively charged in neutral to alkaline water areas. Since the sample water to be treated by the negative membrane method is neutral to alkaline, these microorganisms are negatively charged in the sample water. In the negative membrane method, such a property of microorganisms is utilized to recover the concentrated solution.

[0020] In the example described in Patent Document 1, the particle (A) has a positive surface charge. Therefore, the virus, humic acid, and particle (B), which have a negative surface charge, are adsorbed to the particle (A). At this time, the virus can have a positive surface charge, so it is relatively difficult to adsorb compared to the humic acid and particle (B). As a result, the virus is not adsorbed to the particle (A), and the humic acid and particle (B) are adsorbed to the particle (A). Then, the particle (A) is separated from the sample liquid in a state in which the humic acid or particle (B) is adsorbed, that is, in a state in which the particle size is large. As a result, the humic acid and particle (B) adsorbed to the particle (A) are also separated from the sample liquid together with the particle (A). In this way, a purified virus liquid from which humic acid has been removed can be obtained.

[0021] In addition, in the negative charge membrane method, a concentrated solution of microorganisms is purified by utilizing the property that microorganisms are negatively charged in sample water. Therefore, when prefiltration is performed in the negative charge membrane method, if the prefilter that performs the prefiltration has an electric charge, the microorganisms are captured by the prefilter and do not flow to the negative charge membrane downstream, and as a result, the negative charge membrane cannot capture the microorganisms in the sample water sufficiently. In other words, there is a risk that the recovery efficiency of microorganisms by the negative charge membrane method will decrease.

[0022] Therefore, when performing prefiltration using the negative charge membrane method, it is required to use a prefilter that does not easily capture microorganisms in the sample water. For example, a glass filter is sometimes used as a prefilter for prefiltration. This is because glass filters have the advantages of being less prone to deterioration, being able to ensure the thickness of the filtration layer, and being able to perform prefiltration efficiently. However, glass filters are negatively charged. Also, nylon mesh is sometimes used as a prefilter, but it can be positively charged. Therefore, glass filters and nylon mesh may capture charged microorganisms and are not suitable as prefilters in the negative charge membrane method.

[0023] In addition, in the process of concentrating microorganisms using the negatively charged membrane method, solutions with different pH levels are supplied to the negatively charged membrane in a sequence to control the detachment of particles. Therefore, when filters with different pore sizes are layered as prefilters for the negatively charged membrane, the particles captured by the layered prefilters may be drawn out by the solution supplied to the negatively charged membrane, which may result in the drawing out of undesired particles.

[0024] Thus, even in the negative charge membrane method, if the sample water contains impurities, it is desirable to perform prefiltration, but it is not appropriate to use a charged filter as a prefilter. Also, in the negative charge membrane method, it is necessary to control the attachment and detachment of particles by supplying an appropriate solution to the negative charge membrane, so it is difficult to automate the concentration device that performs the process by the negative charge membrane method.

[0025] A concentrating device and a concentrating method capable of solving the above-mentioned problems will be described below.

[0026] FIG. 1 is a schematic diagram of a concentrating device 100 according to an embodiment of the present disclosure. As shown in FIG. 1, the concentrating device 100 according to the present embodiment includes a control unit 101, a negatively charged membrane 102, a spare membrane 103, a suction bottle 104, a mixed solution storage tank 105, a sample water supply unit 106, an acidic solution storage tank 107, an alkaline solution storage tank 108, and an alarm unit 150. In FIG. 1, solid lines connecting each component indicate piping through which a fluid flows. Also, in FIG. 1, dashed lines connecting each component indicate transmission paths for signals transmitted and received between the control unit 101.

[0027] The control unit 101 is a processor that controls and manages the entire concentrating apparatus 100, including each of the components of the concentrating apparatus 100. The control unit 101 controls a first pump 111, a second pump 112, a third pump 113, and a fourth pump 114, which will be described later, by transmitting control signals to these components. The control unit 101 also acquires information on measured flow rates from a first flow meter 121 and a second flow meter 122, which will be described later. The processing executed by the control unit 101 may be designed using a microcomputer, Raspberry Pi, Arduino, or the like, but is not limited to these. The control unit 101 is composed of a processor such as a CPU (Central Processing Unit) that executes a program that specifies a control procedure. The program executed by the processor is stored, for example, in a storage medium inside or outside the concentrating apparatus 100.

[0028] The negatively charged membrane 102 is a membrane negatively charged. For example, a mixed cellulose membrane (hereinafter, simply referred to as "HA membrane") manufactured by Millipore Corporation can be used as the negatively charged membrane 102. The negatively charged membrane 102 has holes that are permeable to molecules that constitute a fluid, such as water molecules. The pore size (first pore size) of the pores of the negatively charged membrane 102 may be appropriately determined depending on the viruses, etc. to be captured by the negatively charged membrane 102. The first pore size is appropriately determined, for example, within the range of 0.1-30 μm. The negatively charged membrane 102 may be made of a material that can capture viruses, etc. depending on the surface charge of the viruses, etc.

[0029] An upstream pipe 131 for supplying a fluid is provided on the upstream side of the negatively charged membrane 102. A sample water supply pipe 132 is connected to the upstream pipe 131.

[0030] A sample water supply unit 106 is disposed upstream of the negatively charged membrane 102. The sample water supply unit 106 supplies sample water collected from a water treatment plant. The sample water supply unit 106 may be configured as a mechanism for supplying sample water collected from the water treatment plant using a hose or tube, or may be configured as a tank for storing sample water collected at the water treatment plant. A sample water supply pipe 132 is connected to the sample water supply unit 106, and the sample water is supplied to the negatively charged membrane 102 via the sample water supply pipe 132 and the upstream pipe 131 that form a flow path.

[0031] A spare membrane 103 is disposed on the flow path between the sample water supply unit 106 and the negative charge membrane 102. In this embodiment, specifically, the spare membrane 103 is disposed on the sample water supply pipe 132.

[0032] The preliminary membrane 103 functions as a prefilter for performing prefiltration in the concentrator 100. Specifically, the preliminary membrane 103 has holes with a pore size (second pore size) through which microorganisms can pass. For example, the preliminary membrane 103 has pores with a pore size appropriately determined in the range of 0.1-30 μm. In one embodiment, the preliminary membrane 103 may be an uncharged membrane. As a result, the preliminary membrane 103 can transmit the sample water containing microorganisms to the downstream side while capturing impurities larger than the second pore size. In particular, in one embodiment, when the preliminary membrane 103 is not charged, it does not adsorb charged microorganisms. Therefore, the uncharged preliminary membrane 103 can flow charged microorganisms to the downstream side without capturing them. In one embodiment, a negatively charged membrane can be used as the preliminary membrane 103. When a negatively charged membrane is used as the preliminary membrane 103, when filtering sample water that does not contain cations, such as fresh water, microorganisms such as viruses do not form complexes with cations, and therefore pass downstream without being captured by the preliminary membrane 103.

[0033] For example, non-charged nonwoven fabric, cellulose acetate, or low-charged nylon can be used as the membrane material of the preliminary membrane 103. However, the membrane material of the preliminary membrane 103 is not limited to those shown here, and other materials that do not adsorb charged microorganisms can also be used.

[0034] In the sample water supply pipe 132, a first pump 111 is disposed upstream of the preliminary membrane 103. The first pump 111 sends the sample water supplied from the sample water supply unit 106 to the preliminary membrane 103 under the control of the control unit 101.

[0035] The mixed solution storage tank 105 stores a solution (hereinafter simply referred to as "mixed solution") to be mixed with the sample water supplied from the sample water supply unit 106. The mixed solution may be, for example, a magnesium chloride solution, but is not limited to this. An appropriate solution may be used as the predetermined solution depending on the properties of the sample water. In this embodiment, the mixed solution will be described below as a magnesium chloride solution.

[0036] A mixed solution supply pipe 133 for supplying magnesium chloride solution is connected to the mixed solution storage tank 105. The mixed solution supply pipe 133 merges with the flow path (sample water supply pipe 132 in this embodiment) upstream of the negative charge membrane 102 and downstream of the preliminary membrane 103. Thus, the magnesium chloride solution is supplied from the mixed solution storage tank 105 to the sample water supply pipe 132 through the mixed solution supply pipe 133. Therefore, in this embodiment, the magnesium chloride solution, which is the mixed solution, is added to the sample water pre-filtered by the preliminary membrane 103. If the mixed solution is added upstream of the preliminary membrane 103, negatively charged microorganisms contained in the sample water and magnesium ions contained in the mixed solution are adsorbed, and the adsorbed complex becomes positively charged. As a result, the adsorbed complex may be captured by the preliminary membrane 103 due to the charge that the preliminary membrane may have. This may reduce the number of microorganisms contained in the sample water supplied to the negative charge membrane 102. However, by adding a mixed solution to the sample water that has been prefiltered as in the present embodiment, as described above, positively charged microparticles that have been adsorbed to magnesium ions are not captured by the preliminary membrane 103, thereby preventing a decrease in the efficiency of microorganism recovery by the concentrating device 100.

[0037] In the sample water supply pipe 132, a second pump 112 and a first flow meter 121 are disposed upstream of a junction P with the mixed solution storage tank 105 and downstream of the spare membrane 103. The second pump 112 is a pump that sends the sample water pre-filtered by the spare membrane 103 to the downstream side under the control of the control unit 101. The first flow meter 121 measures the flow rate of the sample water sent downstream by the second pump 112. The first flow meter 121 transmits information related to the measured flow rate to the control unit 101. The control unit 101 controls the sending of the liquid by the second pump 112 based on the acquired information related to the flow rate.

[0038] A fourth pump 114 and a second flow meter 122 are disposed in the mixed solution supply pipe 133. The fourth pump 114 is a pump that sends the mixed solution downstream under the control of the control unit 101. The fourth pump 114 may be, for example, a Peristaltic Pump (registered trademark) that sends the solution by squeezing a soft tube with a roller. The second flow meter 122 measures the flow rate of the mixed solution sent downstream by the fourth pump 114. The second flow meter 122 transmits information related to the measured flow rate to the control unit 101. The control unit 101 controls the sending of the solution by the fourth pump 114 based on the acquired information related to the flow rate.

[0039] In this way, the control unit 101 controls the liquid delivery by the second pump 112 and the fourth pump 114 based on the information on the flow rate acquired from the first flow meter 121 and the second flow meter 122, respectively. This allows the control unit 101 to adjust the mixing ratio of the mixed solution to the sample water. The sample water mixed with the mixed solution is supplied to the negatively charged membrane 102 via the upstream piping 131.

[0040] The acidic solution storage tank 107 is a tank that stores an acidic aqueous solution (acidic solution). In this specification, the acidic aqueous solution is described as a sulfuric acid solution as an example, but is not limited to this. An acidic solution supply pipe 134 that supplies the acidic solution from the acidic solution storage tank 107 is connected to the acidic solution storage tank 107. The acidic solution supply pipe 134 merges with the flow path (the upstream pipe 131 in this embodiment) downstream of the junction P and upstream of the negative charge membrane 102.

[0041] The alkaline solution storage tank 108 is a tank that stores an alkaline aqueous solution (alkaline solution). In this specification, the alkaline aqueous solution is described as an aqueous sodium hydroxide solution as an example, but is not limited to this. An alkaline solution supply pipe 135 that supplies the alkaline solution from the alkaline solution storage tank 108 is connected to the alkaline solution storage tank 108. The alkaline solution supply pipe 135 merges with the flow path (the upstream pipe 131 in this embodiment) downstream of the junction P and upstream of the negative charge membrane 102.

[0042] A downstream pipe 141 is provided on the downstream side of the negatively charged membrane 102 to discharge the fluid that has passed through the negatively charged membrane 102. Two different pipes 142 and 143 are branched and connected to the downstream pipe 141.

[0043] A third pump 113 is disposed in the first downstream pipe 142. The first downstream pipe 142 discharges a fluid from an outlet 110. The third pump 113 is a suction pump that draws a fluid from the negatively charged film 102 to the first downstream pipe 142 side under the control of the control unit 101. The third pump 113 may be configured, for example, by an aspirator that draws in a fluid by creating a reduced pressure state.

[0044] A suction bottle 104 is disposed downstream of the downstream second piping 143. The suction bottle 104 draws in the fluid supplied to the negatively charged membrane 102 by creating a reduced pressure state, and collects the fluid in a concentrated liquid collection container 104a provided therein.

[0045] The notification unit 150 notifies information. The notification unit 150 may be capable of notifying information by sound, vibration, image, or the like. The notification unit 150 may be configured to include, for example, a speaker and may notify information by sound. The notification unit 150 may be configured to include, for example, a vibrator and may notify information by vibration. The notification unit 150 may be configured to include a display. In this case, the display may function as the notification unit 150 and notify information by displaying an image. Note that the notification unit 150 does not necessarily have to be provided in the concentrating device 100. For example, the concentrating device 100 may be connected to an external electronic device so as to be capable of communicating information, and information may be transmitted from the concentrating device 100 to the external electronic device, and information may be notified from a notification unit provided in the external electronic device.

[0046] In this embodiment, when the filtration resistance of the preliminary membrane 103 becomes equal to or greater than a predetermined threshold, the notification unit 150 notifies the user that the filtration resistance has become equal to or greater than a predetermined threshold under the control of the control unit 101. Specifically, the control unit 101 determines whether the filtration resistance of the preliminary membrane 103 has become equal to or greater than a predetermined threshold. For example, the concentrating device 100 includes pressure indicators on the upstream and downstream sides of the preliminary membrane 103 in the sample water supply pipe 132. The control unit 101 calculates the filtration resistance of the preliminary membrane 103 by detecting the transmembrane pressure difference of the preliminary membrane 103 based on the value indicated by the pressure indicator. When the control unit 101 determines that the calculated filtration resistance is equal to or greater than a predetermined threshold, the notification unit 150 notifies the user of the filtration resistance. The predetermined threshold may be determined as an appropriate value that can detect, for example, that the preliminary membrane 103 is beginning to become clogged. When the control unit 101 determines that the filtration resistance is equal to or greater than a predetermined threshold, it is possible that the capture of impurities in the reserve membrane 103 has progressed, making it impossible to filter at a certain rate or higher. Therefore, a manager of the concentrating device 100 who has confirmed the notification from the notification unit 150 can maintain the filtration performance of the reserve membrane 103 by inspecting or cleaning the reserve membrane 103 or replacing the reserve membrane 103. In this way, the notification unit 150 can prevent problems such as a decrease in the processing performance of the concentrating device 100.

[0047] When the control unit 101 determines that the calculated filtration resistance is equal to or greater than a predetermined threshold value, the control unit 101 may stop the operation of the concentrating device 100 by an interlock or the like.

[0048] Next, the procedure of the negative charge membrane method using the concentrating device 100 shown in Fig. 1 will be described with reference to Fig. 2 to Fig. 4. Fig. 2 to Fig. 4 are schematic diagrams for explaining each step of the process of the negative charge membrane method executed by the concentrating device 100. In Fig. 2 to Fig. 4, the thick solid lines represent the flow of fluid, and the thick dashed lines represent the flow of signals. In the concentrating device 100, a concentrated solution of virus particles is recovered by the negative charge membrane method in the first to third steps.

[0049] Fig. 2 is a schematic diagram for explaining the first step of the treatment of the negative charge membrane method performed by the concentrating apparatus 100 of Fig. 1. The first step is a step for filtering the sample water.

[0050] In the first step, the control unit 101 drives the first pump 111, the second pump 112, the third pump 113, and the fourth pump 114. In particular, the control unit 101 controls the liquid delivery by the second pump 112 and the fourth pump 114 based on information on the flow rates acquired from the first flow meter 121 and the second flow meter 122, respectively.

[0051] In the first step, as shown by the thick solid line in Fig. 2, sample water is supplied from the sample water supply unit 106. The sample water supplied from the sample water supply unit 106 is pre-filtered by the preliminary membrane 103. As a result, impurities contained in the sample water are captured by the preliminary membrane 103, as shown diagrammatically in Fig. 2.

[0052] The pre-filtered sample water is supplied further downstream. The flow rate of the sample water is controlled by the liquid delivery control of the second pump 112. Furthermore, the control unit 101 controls the liquid delivery by the second pump 112 and the fourth pump 114 based on information on the flow rates acquired from the first flow meter 121 and the second flow meter 122, respectively, so that the mixed solution is mixed into the sample water while adjusting the mixing ratio of the mixed solution to the sample water.

[0053] When the mixed solution is mixed with the sample water, the negatively charged microorganisms contained in the sample water are adsorbed to the cations (magnesium ions in this case) contained in the mixed solution. The microorganisms are captured by the negatively charged membrane 102 while being adsorbed to the cations.

[0054] After the microorganisms are captured by the negatively charged membrane 102, the permeated fluid is drawn downstream by the third pump 113 and discharged from the outlet 110 via the downstream piping 141 and the first downstream piping 142.

[0055] Fig. 3 is a schematic diagram for explaining the second step of the treatment of the negative charge membrane method performed by the concentrating apparatus 100 of Fig. 1. The second step is a step of washing the negative charge membrane 102 with an acid.

[0056] In the second step, the third pump 113 is driven by the control unit 101. In the second step, as shown by a thick solid line in FIG. 3, an acid solution is supplied from the acid solution storage tank 107. The acid solution is supplied from the acid solution storage tank 107 to the negatively charged membrane 102 via the acid solution supply pipe 134 and the upstream pipe 131, and the negatively charged membrane 102 is acid-washed. As a result, the cations captured by the negatively charged membrane 102 in the first step are drawn out from the negatively charged membrane 102. The acid solution containing the drawn out cations is drawn downstream by the third pump 113 and discharged from the discharge port 110 via the downstream pipe 141 and the first downstream pipe 142. In this way, the cations are removed from the negatively charged membrane 102.

[0057] The acidic solution may be, for example, a 0.5 mM sulfuric acid solution with a pH of 3.0. The amount of the sulfuric acid solution to be supplied is preferably a volume that allows the sulfuric acid solution to be evenly in contact with the entire membrane surface of the negatively charged membrane 102. For example, the amount of the sulfuric acid solution to be supplied may be 1 / 10 the volume of the sample water or 10 mL or more.

[0058] The concentrating device 100 may be configured to include a valve downstream of the negatively charged membrane 102, and to be capable of controlling the time or state of contact between the sulfuric acid solution and the membrane and the immersion. In order to uniformly immerse the negatively charged membrane 102 in the sulfuric acid solution, when the negatively charged membrane 102 has a flat membrane structure, it is preferable to control the delivery of the sulfuric acid solution so that the sulfuric acid solution is uniformly spread over the membrane surface by about several millimeters. When the negatively charged membrane 102 has a housing shape, it is preferable to control the delivery of the sulfuric acid solution so that the sulfuric acid solution is spread on the upstream side of the negatively charged membrane 102. It is preferable that the negatively charged membrane 102 is immersed in the sulfuric acid solution for several seconds or more. This reduces the amount of cations remaining on the negatively charged membrane 102, and more appropriate acid washing can be performed.

[0059] Fig. 4 is a schematic diagram for explaining the third step of the treatment of the negative charge membrane method performed by the concentrating device 100 of Fig. 1. The third step is a step of recovering a concentrated solution of viruses by alkaline extraction.

[0060] In the third step, as shown by the thick solid line in Fig. 4, an alkaline solution is supplied from the alkaline solution storage tank 108. The alkaline solution is supplied from the alkaline solution storage tank 108 to the negatively charged membrane 102 via the alkaline solution supply pipe 135 and the upstream pipe 131, and alkaline evacuation is performed. As a result, the microorganisms captured by the negatively charged membrane 102 in the first step are evacuated from the negatively charged membrane 102.

[0061] Then, by creating a reduced pressure state in the suction bottle 104, the alkaline solution containing the induced microorganisms is drawn into the suction bottle 104 and flows into the concentrated liquid recovery container 104a via the downstream piping 141 and the second downstream piping 143. In this way, a concentrated liquid of the microorganisms is recovered in the concentrated liquid recovery container 104a.

[0062] The alkaline solution may be, for example, a 1.0 mM aqueous sodium hydroxide solution having a pH of 10.5-10.8. The amount of the aqueous sodium hydroxide solution to be supplied may be, for example, 10 ml or more. However, the smaller the amount of the aqueous sodium hydroxide solution to be supplied, the higher the virus concentration effect, and therefore, it is preferable.

[0063] The concentrating device 100 may be configured to include a valve downstream of the negatively charged membrane 102, and to be capable of controlling the time or state of contact and immersion of the sodium hydroxide aqueous solution with the negatively charged membrane 102. In order to uniformly immerse the sodium hydroxide aqueous solution in the negatively charged membrane 102, when the negatively charged membrane 102 has a flat membrane structure, it is preferable to control the delivery of the sodium hydroxide aqueous solution so that the sodium hydroxide aqueous solution is uniformly spread over the membrane surface by about several millimeters. When the negatively charged membrane 102 has a housing shape, it is preferable to control the delivery of the sodium hydroxide aqueous solution so that the sodium hydroxide aqueous solution is spread on the upstream side of the negatively charged membrane 102. It is preferable that the negatively charged membrane 102 is immersed in the sodium hydroxide aqueous solution for several seconds or more. This allows more viruses to be induced from the negatively charged membrane 102 and collected as a concentrated virus solution.

[0064] Thus, the concentrating apparatus 100 according to this embodiment includes the negatively charged membrane 102 and the spare membrane 103 arranged upstream of the negatively charged membrane 102. The spare membrane 103 functions as a pre-filtration filter that removes impurities contained in the sample water, thereby preventing clogging of the filtration in the negatively charged membrane 102, maintaining the recovery efficiency of microorganisms, and improving the quality of the concentration method.

[0065] In the concentrating device 100 according to the above embodiment, the second pore size of the spare membrane 103 functioning as a pre-filtration filter may be set smaller than the first pore size of the negatively charged membrane 102 performing the desired filtration. This allows the spare membrane 103 functioning as a pre-filtration filter to remove smaller impurities, thereby further suppressing clogging of the negatively charged membrane 102 and allowing the negatively charged membrane 102 to capture microorganisms by utilizing an electric charge.

[0066] In the above embodiment, the spare membrane 103 may be disposable and replaced after each concentration process. In this case, problems such as an extreme decrease in the processing capacity of the spare membrane 103 are unlikely to occur, so the concentrating device 100 does not need to include the notification unit 150.

[0067] In the above embodiment, the larger the diameter of the preliminary membrane 103 and the larger the filtration area of ​​the preliminary membrane 103, the higher the filtration efficiency that can be maintained in the negatively charged membrane 102.

[0068] The microorganisms to be captured by the negatively charged membrane 102 of the concentrating device 100 according to the above embodiment include bacteria and viruses. The virus may be any known virus. The virus may include, for example, a double-stranded DNA virus, a single-stranded DNA virus, a double-stranded RNA virus, a single-stranded RNA virus, a single-stranded RNA virus, a single-stranded RNA reverse transcription virus, or a double-stranded DNA reverse transcription virus.

[0069] Moreover, the concentrating device 100 according to the above embodiment can be similarly applied to charged particles suspended in liquid and colloidal dispersions.

[0070] The concentrating apparatus 100 described above can be used in various fields and applications. For example, the concentrating apparatus 100 described above can be used to grasp water quality management and treatment performance in a small area such as water treatment infrastructure such as a water purification plant, a sewage treatment plant, a water reclamation facility, or a seawater desalination facility, or a water treatment facility for each facility such as a building purification facility, a hospital, or a school. The concentrating apparatus 100 described above can be used for, for example, a dynamic survey of the environment in aquatic areas such as a river, an ocean, aquatic areas, a pool, or a bathing area. The concentrating apparatus 100 described above can be used for, for example, water quality testing of fine particles, colloidal dispersions, or microorganisms to grasp the microbial infection risk in a city that covers aquatic areas and environmental infrastructure. The concentrating apparatus 100 described above can be used to quantify risk and perform comparative verification with a threshold value that can be determined as safe, for the purpose of qualitative risk, safety understanding, or quality control of liquids used in the production of beverages or processed foods. The concentrating apparatus 100 described above can be used for water quality testing of industrial water, irrigation water, agricultural water, and the like. The concentrating device 100 described above can be used to perform quality control, safety assessment, or quality control of liquids used for temperature and humidity control in mist spraying, humidification devices, sprinkling water, etc. The concentrating device 100 described above can be used for quality control inspection of water related to medical treatment such as pharmaceutical manufacturing or artificial dialysis therapy.

[0071] The present disclosure is not limited to the configurations specified in the above-mentioned embodiments, and various modifications are possible within the scope of the gist of the disclosure described in the claims. For example, the functions included in each component, step, etc. can be reconfigured so as not to cause logical inconsistencies, and multiple components or steps can be combined into one or divided. [Explanation of symbols]

[0072] 100 Concentrator 101 Control section 102 Negative charge film 103 Spare Film 104 Suction bottle 104a Concentrate collection container 105 Mixed solution storage tank 106 Sample water supply unit 107 Acid Solution Storage Tank 108 Alkaline solution storage tank 110 Outlet 111 First Pump 112 Second Pump 113 3rd Pump 114 4th Pump 121 1st flow meter 122 2nd flow meter 131 Upstream piping 132 Sample water supply pipe 133 Mixed solution supply piping 134 Acid solution supply piping 135 Alkaline solution supply piping 141 Downstream piping 142 Downstream first pipe 143 Downstream second piping 150 Notification Department P confluence

Claims

1. a negatively charged membrane having pores of a first pore size and negatively charged; a sample water supply unit arranged upstream of the negative charge membrane and supplying sample water; a spare membrane disposed on a flow path between the sample water supply unit and the negatively charged membrane, the spare membrane having holes with a second pore size; a mixed solution storage tank for storing a mixed solution containing cations capable of adsorbing to negatively charged microorganisms contained in the sample water, to be mixed with the sample water; a mixed solution supply pipe that joins the flow path upstream of the negative charge membrane and downstream of the spare membrane and supplies the mixed solution from the mixed solution storage tank; an acid solution storage tank for storing an acid solution; an acid solution supply pipe that joins the flow path downstream of a joining point between the flow path and the mixed solution supply pipe and upstream of the negative charge membrane, and that supplies the acid solution from the acid solution storage tank; an alkaline solution storage tank for storing an alkaline solution; an alkaline solution supply pipe that joins the flow path downstream of a joining point between the flow path and the mixed solution supply pipe and upstream of the negative charge membrane, for supplying the alkaline solution from the alkaline solution storage tank; A concentrating device comprising:

2. 2. The concentrator of claim 1, wherein the second pore size is a pore size of 0.1-30 μm.

3. The concentrating device according to claim 1 or 2, wherein the second pore size is smaller than the first pore size.

4. The concentrating apparatus according to claim 1 , further comprising an alarm unit that, when a filtration resistance of the preliminary membrane becomes equal to or greater than a predetermined threshold, notifies the user that the filtration resistance has become equal to or greater than a predetermined threshold.

5. a negatively charged membrane having pores of a first pore size and negatively charged; a sample water supply unit arranged upstream of the negative charge membrane and supplying sample water; a spare membrane disposed on a flow path between the sample water supply unit and the negatively charged membrane, the spare membrane having holes with a second pore size; a mixed solution storage tank for storing a mixed solution containing cations capable of adsorbing to negatively charged microorganisms contained in the sample water, to be mixed with the sample water; a mixed solution supply pipe that joins the flow path upstream of the negative charge membrane and downstream of the spare membrane and supplies the mixed solution from the mixed solution storage tank; an acid solution storage tank for storing an acid solution; an acid solution supply pipe that joins the flow path downstream of a joining point between the flow path and the mixed solution supply pipe and upstream of the negative charge membrane, and that supplies the acid solution from the acid solution storage tank; an alkaline solution storage tank for storing an alkaline solution; an alkaline solution supply pipe that joins the flow path downstream of a joining point between the flow path and the mixed solution supply pipe and upstream of the negative charge membrane, for supplying the alkaline solution from the alkaline solution storage tank; A concentration method performed by a concentration device comprising: a first step of supplying the sample water from the sample water supply unit to the negatively charged membrane and supplying the mixed solution from the mixed solution storage tank to mix the sample water with the mixed solution; A second step of supplying the acidic solution from the acidic solution storage tank to the negatively charged membrane; a third step of supplying the alkaline solution from the alkaline solution storage tank to the negatively charged membrane; The method of the present invention comprises the steps of:

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