TWI837129B - Diagnostic device for reverse osmosis systems - Google Patents

Abstract

A diagnostic device for a reverse osmosis system diagnoses the operating state of an RO system, wherein the RO system includes a pretreatment device 1 and an RO device 5 for performing membrane filtration on coagulation treatment water from the pretreatment device 1. The diagnostic device for the reverse osmosis system includes: a receiving unit for flux data of the RO device 5; an input unit for operating state information of the RO system; a storage unit for storing data indicating the relationship between an operating malfunction state of the RO system and a countermeasure; and a determination unit 35 for determining a countermeasure for the operating malfunction of the RO device based on the operating state information input by the input unit and the data stored in the storage unit.

Description

Reverse Osmosis System Diagnostic Device

The present invention relates to a diagnostic device for determining countermeasures for malfunction of a reverse osmosis (RO) system after defogging water has been treated with a membrane.

Various water treatments are performed in water treatment, various drainage treatments, and drainage recovery using well water, industrial water, tap water, etc. as raw water. For example, after adding a coagulant to the raw water to aggregate and coarsen suspended matter, colloidal components, or organic matter in the raw water, water treatment is performed to separate solids and liquids by sedimentation, suspension, filtration, membrane filtration, etc. Water treatment is performed to remove dirt and bacteria by membrane filtration alone and recover the treated water.

Generally, the causes of RO membrane clogging include: (i) excessive turbidity in the water supply; (ii) adhesion of scale and slime; (iii) poor pre-treatment if there is pre-treatment. As a countermeasure, the following operations can be performed.

Regarding (i), for example, the silt density index (SDI) of RO feed water is measured. If it is above the specified SDI, it is handled by changing the pretreatment conditions. Regarding (ii), for example, the water quality of RO feed water, RO treated water, and RO concentrated water is measured to optimize the recovery rate. Regarding (iii), the concentration of the coagulant added in the pretreatment is confirmed, and if it is above the allowable concentration, it is adjusted to below the allowable concentration.

When the filtration resistance of the RO membrane increases, backwashing or cleaning with chemicals such as acid and alkali is performed (Patent Document 1, etc.).

When the RO membrane ages, the flux may increase beyond the specified range.

[Patent document 1] Japanese Patent Publication No. 2016-185520

There are many reasons for RO membrane clogging, including excessive turbidity in the water supply, adhesion of scale or sludge, and poor pretreatment. The response strategy varies depending on the cause, so it is required to accurately determine the cause and quickly and appropriately establish a response strategy.

The purpose of the present invention is to provide a reverse osmosis system diagnostic device that can accurately determine countermeasures for malfunction of the reverse osmosis (RO) system.

The reverse osmosis system diagnostic device of the present invention diagnoses the operating state of the reverse osmosis system. The reverse osmosis system includes a pre-treatment device and a reverse osmosis device for performing reverse osmosis treatment on pre-treated water from the pre-treatment device. The reverse osmosis system diagnostic device includes: index data related to the permeability of the reverse osmosis device and the primary side flow path differential pressure. a receiving unit for receiving at least one of the reverse osmosis system; an input unit for inputting the operating status information of the reverse osmosis system; a storage unit for storing data indicating the relationship between the operating malfunction state and the countermeasures of the reverse osmosis system; and a determination unit for determining the countermeasures for the operating malfunction of the reverse osmosis device based on the operating status information input by the input unit and the data stored in the storage unit.

In one form of the present invention, the input unit includes a display component for displaying multiple questions and an input component for answering the questions.

In one form of the present invention, the operating status information includes the ratio of the concentrated water of the reverse osmosis device to the silt density index (SDI) value of the supply water.

In one form of the present invention, the operating status information includes the SDI value of the water supplied to the reverse osmosis device.

In one form of the present invention, the pre-treatment device includes a coagulation treatment device and a filter membrane device for coagulation treatment water, and the operating status information further includes the SDI value of the filtered water of the filter membrane device.

In one form of the present invention, the operating status information includes the concentration ratio of the non-precipitating standard substance and the concentration ratio of the scale-forming substance in the reverse osmosis device.

In one form of the present invention, the operating status information includes the conductivity of the supply water and permeate water to the reverse osmosis device, the free chlorine concentration of the reverse osmosis supply water, and the oxidation-reduction potential (ORP) of the reverse osmosis supply water.

In one form of the present invention, the receiving unit receives index data related to the permeability of the reverse osmosis device, and the index data related to the permeability is the corrected flux.

In one aspect of the present invention, when the corrected flux of the reverse osmosis device is outside a specified range, or when the rate of decrease of the corrected flux is greater than a specified value, the determination unit performs the diagnosis.

In one form of the present invention, the receiving unit receives the primary side flow path differential pressure of the reverse osmosis membrane device, and when the primary side flow path differential pressure of the reverse osmosis membrane device is greater than a specified value, or when the rising speed of the membrane differential pressure is greater than a specified value, the determining unit performs the diagnosis.

According to the present invention, the operating status of the RO system can be accurately diagnosed.

According to one aspect of the present invention, the cause of malfunction of the RO system can be appropriately determined.

1: Pre-processing device

1a: Coagulation treatment device

1b: Filter device

1c: Filtered water inflow piping to relay tank 1d

1d: Relay slot

1e: Piping and piping from the relay tank 1d to the pump 2

2: Pump

3, 7, 18: Valve

4, 6, 17: Piping

5:RO device

5a:RO membrane

8, 9, 27: Pressure sensor

9A, 27A: Flow meter

9B: Thermometer

19: pH meter

20: Operational circuit

20A: Primary side flow path differential pressure detection circuit

21: Alarm circuit

23, 26, 28: Conductivity meter

24: ORP meter

25: Free chlorine meter

30, 30A: Diagnostic device

31: Main body

32: Data Collection Department

33: Data Storage Department

34: Database (storage department)

35: Judgment Department

36: Display panel/LCD display panel

Y, N: switch

Figure 1 is a diagram of the RO system structure.

Figure 2 is a diagram showing the configuration of the diagnostic device for the RO system.

Figure 3 is a flow chart showing the diagnostic method of the RO system.

Figure 4 is a diagram of the structure of the pre-processing device.

Figure 5 is a diagram of the RO system configuration.

Figure 6 is a diagram showing the configuration of the diagnostic device for the RO system.

FIG7 is a flow chart showing the diagnostic method of the RO system.

In the present invention, the so-called index data related to permeability is the index data related to the permeability of the water to be treated by the reverse osmosis membrane, and can usually be the permeation flux (flux) or the permeation flow rate. In addition, in reverse osmosis treatment, constant flow filtration is often used to keep the treated water volume (permeation water volume) fixed. In this case, the operating pressure, average operating pressure, membrane differential pressure, and effective pressure can be used as the index data related to permeability.

Flux and permeation flow rate vary depending on temperature or membrane differential pressure, so it is better to convert the corrected flux or corrected permeation flow rate under standard membrane differential pressure and standard temperature conditions as index data related to permeability.

Permeate flow, permeate flow rate, operating pressure, average operating pressure, membrane differential pressure, effective pressure, and corrected flux are terms defined in Japanese Industrial Standard (JIS) K3802:2015 (Membrane Terminology), as described below.

Flux: The amount of water passing through a unit membrane area per unit time.

Permeate flow rate: The amount of water that passes through the membrane per unit time.

Operating pressure: The pressure before the supply water is pressed into the device by the pressurized module.

Average operating pressure: In a pressurized module, the average pressure (P ₀ ) of the supply water pressure (P _in ) and the concentrated water pressure (P _out ) as shown in the following equation (1). Unlike the membrane differential pressure, the secondary side pressure (P _prod ) does not need to be subtracted.

P ₀ =(P _in +P _out )/2Inter-membrane pressure difference (1)

Trans membrane pressure: The difference between the primary and secondary pressures of a membrane, element or module. In cross flow filtration, the average operating pressure is usually used as the primary pressure.

Effective pressure: In a pressurized module, the effective pressure acting on the membrane is the average operating pressure (P ₀ ) minus the osmotic pressure difference (△π) and the secondary side pressure (P _prod ).

Corrected flux: The flux converted to the standard membrane differential pressure and standard temperature conditions.

The following is an example of using corrected flux as index data related to permeability.

FIG1 is a configuration diagram of an RO system of an embodiment. Raw water is subjected to coagulation treatment and filtration treatment by a pre-treatment device 1, and then supplied to an RO device 5 via a pump 2, a valve 3, and a pipe 4. In the embodiment, as shown in FIG4, a device including the following components is used as the pre-treatment device 1: a coagulation treatment device 1a; a filtration device 1b for filtering coagulation treatment water; and a relay tank 1d for storing filtered treatment water, but the present invention is not limited thereto. Symbol 1c indicates an inflow pipe for filtered water to the relay tank 1d, and 1e indicates a pipe from the relay tank 1d to the pump 2. The pipe 1e is provided with a pH meter 19, a conductivity meter 23, an ORP meter 24 and a free chlorine meter 25, and the detection data of these are input to the diagnostic device 30 described later.

As the filtering device 1b, preferably a gravity filter, a pressure filter, a microfiltration (MF) membrane module, an ultrafiltration (UF) membrane module, etc. are used. In the embodiment described above, a hollow fiber UF membrane module is used.

The water passing through the RO membrane 5a of the RO device 5 is taken out as treated water through the pipe 6 and the valve 7, and the raw water that does not pass through the RO membrane 5a is taken out as concentrated water through the pipe 17 and the valve 18. The pressure sensor 8, the pressure sensor 9, and the pressure sensor 27 are respectively provided in the pipe 4, the pipe 6, and the pipe 17. The flow meter 9A, the thermometer 9B, and the conductivity meter 26 are further provided in the pipe 6. The flow meter 27A and the conductivity meter 28 are provided in the pipe 17. The detection values of the flow meter 9A, the pressure sensor 8, the pressure sensor 9, the pressure sensor 27, and the thermometer 9B are input to the calculation circuit 20, and the correction flux (correction of the permeation flux) is calculated. In addition, the detected pressures of the pressure sensors 8 and 27 are input to the calculation circuit 20, and the difference between the two is calculated as the primary flow path differential pressure.

As shown in FIG2 , the diagnostic device 30 includes a main body 31 and a liquid crystal display panel 36 having a touch switch function as an input unit. The main body 31 includes a data collection unit 32, a data storage unit 33, a database (storage unit) 34 and a determination unit 35.

The main body 31 includes a computer composed of a central processing unit (CPU), a flash memory, a read-only memory (ROM), a random access memory (RAM), a hard disk, etc.

The CPU of the main unit 31 executes the management program to realize the functions of the data collection unit 32, the data storage unit 33, the database 34 and the judgment unit 35.

In addition to receiving the corrected flux and primary flow path differential pressure data from the calculation circuit 20, the data from the conductivity meters 23, 26, 28, ORP meter 24, free chlorine meter 25, pH meter 19 and thermometer 9B, the data collection unit 32 also receives the response data of the diagnostic item category data from the display panel 36. The data storage unit 33 stores the response data and the judgment results described later together with the corrected flux, primary flow path differential pressure, conductivity, ORP, free chlorine, pH and other operating data. In the database 34, data indicating the malfunction status of the RO system and the countermeasures for the malfunction status are stored.

The determination unit 35 determines the countermeasures based on the data collected by the data collection unit 32 and the countermeasure data in the database 34, and displays them on the display panel 36.

As shown in FIG3 , when the correction flux of the RO device 5 is outside the specified range, or when the rate of decrease of the correction flux is above the specified value, an alarm is activated, and for example, the following multiple question characters Q1 to Q6 are displayed on the display panel 36. In addition, the yes answer switch Y and the no answer switch N are displayed adjacent to the right side of each question character. The answer switch Y and the answer switch N each have a lighting function that turns bright when the switch is touched once and turns dark when touched again. Among Y and N, the one that glows brightly indicates the selected answer. The answer operation is performed by the person in charge of the operation of the RO system, etc.

The UV260 of Q3 below indicates the organic matter measured by ultraviolet absorption spectrophotometry at a wavelength of 260nm. The removal rate of the conductivity of Q7 is shown in the following formula.

Q1: Is the SDI of RO concentrated water less than 3?

Q2: Na concentration ratio < (TOC concentration ratio + α)?

Q3: Na concentration ratio < (UV260 concentration ratio + β)?

Q4: Na concentration ratio < (Si concentration ratio + γ)?

Q5: Na concentration ratio < (Ca concentration ratio + δ)?

Q6: Na concentration ratio < (Mg concentration ratio + ε)?

Q7: Is the conductivity removal rate above ζ%?

Q8: Is the free chlorine concentration of RO water supply <η mg/L as Cl ₂ ?

Q9: Is OPR of RO water supply <θ mV?

α, β, γ, δ, ε, ζ, η, θ represent specific numbers. The question text is an example, and other question texts may be further displayed.

After answering all the question texts by touching switch Y or switch N, touch the input (Enter, Ent) switch indicating the end of the answer. In this way, the answer data is sent from the display panel 36 to the data collection unit 32.

When the answer to Q1 is N, the determination unit 35 reads the following countermeasures a1 to a3 from the database 34 and displays them on the display panel 36.

a1: Increase the amount of slime control agent added.

a2: Perform chemical cleaning.

a3: (If the performance has not been restored) replace the membrane.

When the answer to at least one of Q2 and Q3 is N, the following countermeasures b1 to b3 are read from the database 34 and displayed on the display panel 36.

b1: Re-evaluate agglutination conditions.

b2: Perform chemical cleaning.

b3: (If the performance has not been restored) replace the membrane.

If at least one of the answers to Q4 to Q6 is N, it is determined to be scale adhesion, and the following c1 and c2 are displayed.

c1: Re-evaluate the pH value of the RO water supply and double the amount of scale dispersant added (the response strategy varies depending on the type of scale, so contact the management department).

c2: Clean the RO device with chemicals.

In Q2~Q6, other non-precipitating substances such as K or Cl can be used instead of Na. In addition, in Q4~Q6, other scale-forming substances such as Ba, Sr, etc. can be used instead of Si, Ca, and Mg.

If the answer to any one or more of Q7 to Q9 is N, the following d1 and d2 will be displayed.

d1: Check the vessel and replace the membrane if the conductivity removal rate is less than 98%.

d2: When the free chlorine in the RO water supply is detected to be 0.1 mg/L as Cl ₂ or above, or the OPR (oxidation-reduction potential) is 450 mV or above, the concentration of reducing agent added to the RO water supply is increased.

If the answer to any of Q1 to Q9 is Y, the data is read from database 34 and displayed as follows. "Please contact the management department because a detailed water quality analysis is required."

Furthermore, as the question, "Even if chemical cleaning is performed, will the correction flux not be restored?" can be added. If the answer to this question is Y (not restored), "The RO membrane has aged, so please replace the RO membrane." or "Please contact the management department." etc. will be displayed.

In this way, when the RO system fails, effective countermeasures can be taken as soon as possible.

FIG. 5 is a configuration diagram of an RO system of another embodiment. The same symbols are used for the same parts as FIG. 1. The raw water is subjected to coagulation treatment and filtration treatment by the pre-treatment device 1, and then supplied to the RO device 5 via the pump 2, the valve 3 and the piping 4. In the embodiment, as shown in FIG. 4, the pre-treatment device 1 is used to include the following components: a coagulation treatment device 1a; a filtering device 1b, which performs filtering treatment on the coagulation treatment water; and a relay tank 1d, which stores the filtered treatment water, but is not limited to this. Symbol 1c represents the inflow piping of the filtered water to the relay tank 1d, and 1e represents the piping from the relay tank 1d to the pump 2. A pH meter 19 is provided in the piping 1e.

The water that passes through the RO membrane 5a of the RO device 5 is taken out as treated water through the pipe 6 and the valve 7, and the raw water that does not pass through the RO membrane 5a is taken out as concentrated water through the pipe 17 and the valve 18. Pressure sensors 8, 9, and 27 are respectively installed in the pipe 4, the pipe 6, and the pipe 17. In addition, a flow meter 9A and a thermometer 9B are installed in the pipe 6.

The detection pressures of the pressure sensors 8 and 27 are input to the primary flow path differential pressure detection circuit 20A, and the difference between the two is calculated as the primary flow path differential pressure. When the differential pressure is too large (above the specified value a), or the rising speed of the differential pressure is too large (above the specified value b), a signal is sent to the alarm circuit 21 to generate an alarm formed by sound and/or light, and a signal is sent to the diagnostic device 30A to perform a diagnosis.

As shown in FIG6 , the diagnostic device 30A includes a main body 31 and a liquid crystal display panel 36 having a touch switch function as an input unit. The main body 31 includes a data collection unit 32, a data storage unit 33, a database (storage unit) 34, and a determination unit 35.

In addition to receiving the primary side flow path differential pressure data, the data collection unit 32 also receives the response data and the corrected flux data of the diagnostic item category data from the display panel 36. The data storage unit 33 stores the response data and the judgment results described later together with the primary side flow path differential pressure, corrected flux and other operating data. In the database 34, data indicating the malfunction status of the RO system and the countermeasures for the malfunction status are stored.

The determination unit 35 determines the countermeasure based on the response data from the display panel 36 collected by the data collection unit 32 and the countermeasure data in the database 34, and displays it on the display panel 36.

As shown in FIG7 , when the primary side flow path differential pressure of the RO device 5 is abnormal (the primary side flow path differential pressure or the primary side flow path differential pressure rising speed is above the specified value), an alarm is activated, and the following multiple question characters Q1 to Q6 are displayed on the display panel 36, for example. In addition, a yes answer switch Y and a no answer switch N are displayed adjacent to the right side of each question character. The answer switch Y and the answer switch N each have a lighting function that turns bright when the switch is touched once and turns dark when touched again. Of Y and N, the one that glows brightly indicates the selected answer. The answer operation is performed by the person in charge of the operation of the RO system, etc. Furthermore, the display panel 36 can also display the alarm switch along with the alarm action, and when the person in charge of operation touches the alarm switch, the question text, etc. can be displayed.

Q1: Is the SDI of the water flowing into the relay tank less than α?

Q2: Is the SDI of the water flowing into the relay tank less than β?

Q3: Is the ratio of (SDI of RO concentrated water)/(SDI of RO feed water) greater than γ?

Q4: Na concentration ratio < (Si concentration ratio + δ)?

Q5: Na concentration ratio < (Ca concentration ratio + ε)?

Q6: Na concentration ratio < (Mg concentration ratio + ζ)?

Furthermore, α, β, γ, δ, ε, and ζ represent specific numbers. The question text is an example, and other question texts may also be displayed.

After answering all the question texts by touching switch Y or switch N, touch the input switch indicating the end of the answer. In this way, the answer data is sent from the display panel 36 to the data collection unit 32.

When the answer to Q1 is N, the determination unit 35 reads the following countermeasures A1 and A2 from the database 34 and displays them on the display panel 36.

A1: Insert the pin into the UF module.

A2: Perform chemical cleaning.

Furthermore, "inserting a pin" in countermeasure A1 means inserting a pin to block the hollow fibers in the hollow fiber module if they are damaged.

If the answer to Q2 is N, it is judged to be biological contamination, and the following countermeasures B1 and B2 are read from the database 34 and displayed on the display panel 36.

B1: Increase the amount of viscosity control agent added.

B2: Perform chemical cleaning on the RO device.

If the answer to Q3 is N, C1 and C2 are displayed as follows.

C1: Re-evaluate pre-treatment conditions.

C2: Chemical cleaning of the RO device.

If the answer to at least one of Q4 to Q6 is N, it is determined to be scale adhesion, and the following D1 and D2 are displayed.

D1: Re-evaluate the pH of the RO water supply and double the amount of scale dispersant added (the response strategy varies depending on the type of scale, so contact the management department).

D2: Chemical cleaning of the RO device.

In Q4~Q6, other non-precipitating substances such as K or Cl can be used instead of Na. In addition, in Q4~Q6, other scale-forming substances such as Ba, Sr, etc. can be used instead of Si, Ca, and Mg.

If the answer to any of Q1 to Q6 is Y, the data is read from database 34 and displayed as follows. "Please contact the management department because a detailed water quality analysis is required."

Furthermore, as the question, "Even if chemical cleaning is performed, will the differential pressure of the primary flow path not be restored?" can be added. If the answer to this question is Y (not restored), "The RO membrane has aged, so please replace the RO membrane" or "Please contact the management department." will be displayed.

In this way, when the RO system fails, effective countermeasures can be taken as soon as possible.

Although the present invention is not particularly limited, examples of raw water include tap water, industrial water, well water, and all drainage water.

The coagulant and coagulant aid used for the coagulation treatment are not particularly limited, but it is ideal to use an iron-based coagulant. In addition, the coagulation treatment may be omitted depending on the water quality.

When using an iron-based coagulant, the preferred pH is 4.5 to 7.0, and the most preferred pH is 5.0 to 6.0. If the pH is too low, there is a risk of clogging the membrane due to iron leakage. If the pH is too high, there is a possibility of poor coagulation.

It is better to add an oxidant (usually sodium hypochlorite) to the raw water. The preferred amount of addition is about 0.3mg/LasCl ₂ ~1.0mg/LasCl ₂ .

When a membrane filtration module is used in the filtration device 1b, it can be either a crossflow method or a total amount filtration method.

The treatment steps using the membrane filtration module include water flow, air bubbling, backwashing, and water filling. The filtration water flow time is 20 minutes to 40 minutes. The initial membrane differential pressure (the difference between the primary and secondary side pressures of the element or module) is about 0.02MPa~0.05MPa. When the membrane differential pressure becomes 0.07MPa~0.10MPa, it is better to perform chemical cleaning. The material of the membrane is polyvinylidene fluoride (PVDF), which has good chemical resistance. The pore size is preferably 0.01μm~0.5μm.

The amount of brine in the RO device 5 is preferably 3.6 m ³ /h or more. The RO membrane is not particularly limited, but an ultra-low pressure membrane with a standard pressure of 0.735 MPa is preferred, and the membrane area is preferably 35 m ² ~41 m ² . The initial pure water flux is preferably: 1.0 m/d (25°C) or more, 0.735 MPa, and the initial desalination rate is preferably 98% or more. It is preferred to set the recovery rate in a manner such that the calcium hardness Langelier Index is 0 or less. It is preferred to set the recovery rate in a manner such that the concentration of silicon dioxide in the brine is within the solubility. In addition, the recovery rate is usually 50%~80%.

The present invention has been described in detail using a specific form, but a person having ordinary knowledge in the relevant technical field should know that various changes can be made without departing from the intent and scope of the present invention.

This application is based on Japanese Patent Application No. 2018-097216, Japanese Patent Application No. 2018-097218 filed on May 21, 2018, and Japanese Patent Application No. 2018-102582 filed on May 29, 2018, and the entire texts thereof are cited by reference.

1‧‧‧Pre-treatment device

1e‧‧‧Pipes and pipes from the relay tank 1d to the pump 2

2‧‧‧Pump

3, 7, 18... Valve

4, 6, 17‧‧‧Piping

5‧‧‧RO device

5a‧‧‧RO membrane

8, 9, 27‧‧‧Pressure sensor

9A, 27A‧‧‧Flowmeter

9B‧‧‧Thermometer

19‧‧‧pH meter

20‧‧‧Computing circuits

21‧‧‧Alarm circuit

23, 26, 28‧‧‧Conductivity meter

24‧‧‧ORP meter

25‧‧‧Free chlorine meter

30‧‧‧Diagnostic equipment

Claims (7)

A reverse osmosis system diagnostic device diagnoses the operation state of the reverse osmosis system, wherein the reverse osmosis system includes a pre-treatment device and a reverse osmosis device that performs reverse osmosis treatment on pre-treated water from the pre-treatment device. The reverse osmosis system diagnostic device includes: a receiving unit for a correction flux as index data related to the permeability of the reverse osmosis device; an input unit for operating state information of the reverse osmosis system; a storage unit that stores data indicating the relationship between an operational malfunction state of the reverse osmosis system and a countermeasure; and a determination unit that determines a countermeasure for the operational malfunction of the reverse osmosis device based on the operational state information input by the input unit and the data stored in the storage unit. The input unit includes a display component for displaying a plurality of questions and an input component for answering questions. When the corrected flux of the reverse osmosis device is outside the specified range or the decreasing speed of the corrected flux is above the specified value, the determination unit performs the following diagnosis. <Diagnosis method> The following question texts Q1 to Q6 about the reverse osmosis device are displayed on the display component. According to the answers to the question texts Q1 to Q6 inputted in the input component for answering, the following countermeasures are read and displayed on the display component: Q1: Is the sludge density index of the reverse osmosis concentrated water less than 3? Q2: Is the concentration ratio of the non-precipitable standard substance < (total organic carbon concentration ratio +α); Q3: Is the concentration ratio of non-precipitable standard substances < (UV260 concentration ratio + β); Q4: Is the concentration ratio of non-precipitable standard substances < (scale-forming substance concentration ratio + γ); Q5: Is the concentration ratio of non-precipitable standard substances < (scale-forming substance concentration ratio + δ); Q6: Is the concentration ratio of non-precipitable standard substances < (scale-forming substance concentration ratio + ε); α, β, γ, δ, ε, ζ represent specific numbers. UV260 in Q3 represents organic substances measured by ultraviolet absorption spectrophotometry at a wavelength of 260 nm. In the case of "No" in Q1, the following will be displayed: The following countermeasures a1~a3: a1: increase the amount of slime control agent added; a2: perform chemical cleaning; a3: replace the membrane if the performance has not been restored. If at least one of Q2 and Q3 is answered with a no, the following countermeasures b1~b3 are displayed: b1: re-evaluate the coagulation conditions; b2: perform chemical cleaning; b3: replace the membrane if the performance has not been restored. If at least one of Q4~Q6 is answered with a no, it is judged to be scale adhesion, and the following countermeasures c1 and c2 are displayed: c1: re-evaluate the pH value of the reverse osmosis water supply and double the amount of scale dispersant added; c2: perform chemical cleaning on the reverse osmosis device. A diagnostic device for a reverse osmosis system as described in Item 1 of the patent application, wherein the operating status information includes the ratio of the sludge density index value of the concentrated water of the reverse osmosis device to the sludge density index value of the supply water. A diagnostic device for a reverse osmosis system as described in Item 2 of the patent application, wherein the operating status information includes a sludge density index value of the water supplied to the reverse osmosis device. As described in item 3 of the patent application scope, the diagnostic device for the reverse osmosis system, wherein the pre-treatment device includes a coagulation treatment device and a filter membrane device for coagulation treatment water, and the operating status information further includes the sludge density index value of the filtered water of the filter membrane device. A diagnostic device for a reverse osmosis system as described in any one of items 1 to 4 of the patent application scope, wherein the operating status information includes the conductivity of the supply water and permeate water to the reverse osmosis device, the free chlorine concentration of the reverse osmosis supply water, and the redox potential of the reverse osmosis supply water. A reverse osmosis system diagnostic device diagnoses the operation state of the reverse osmosis system, the reverse osmosis system comprising a pre-treatment device and a reverse osmosis device for performing reverse osmosis treatment on pre-treated water from the pre-treatment device, the reverse osmosis system diagnostic device comprising: a receiving unit for receiving the differential pressure of the primary side flow path of the reverse osmosis device; an input unit for inputting the operation state information of the reverse osmosis system; a storage unit for storing data indicating the relationship between the operation state of the reverse osmosis system and the countermeasures; and a determination unit for determining the countermeasures for the operation state of the reverse osmosis device based on the operation state information input by the input unit and the data stored in the storage unit, the input unit comprising a display unit. A display unit for multiple questions and an input unit for answering the questions, when the differential pressure of the primary side flow path of the reverse osmosis device is greater than a specified value, or when the rising speed of the differential pressure of the primary side flow path of the reverse osmosis device is greater than a specified value, the following diagnosis is performed, <Diagnosis method> The following question texts Q1 to Q6 about the reverse osmosis device are displayed on the display unit, and according to the answers to the question texts Q1 to Q6 inputted in the input unit for answering, the following countermeasures are read and displayed on the display unit: Q1: Whether the sludge density index of the water flowing into the relay tank is less than α; Q2: Whether the sludge density index of the water flowing into the relay tank is less than β; Q3: Whether ( =The ratio of the sludge density index of the reverse osmosis concentrated water)/(sludge density index of the reverse osmosis water supply) is greater than γ; Q4: Is the concentration ratio of the non-precipitable standard substance < (the concentration ratio of the scale-forming substance + δ); Q5: Is the concentration ratio of the non-precipitable standard substance < (the concentration ratio of the scale-forming substance + ε); Q6: Is the concentration ratio of the non-precipitable standard substance < (the concentration ratio of the scale-forming substance + ζ); α, β, γ, δ, ε, ζ represent specific numbers. If the answer to Q1 is no, the following countermeasures A1 and A2 are displayed: A1: For those with damage in the hollow fibers in the hollow fiber module of the pre-treatment device, insert a plug A2: Perform chemical cleaning. If the answer to Q2 is no, the following countermeasures B1 and B2 are displayed: B1: Increase the amount of slime control agent added; B2: Perform chemical cleaning on the reverse osmosis device. If the answer to Q3 is no, the following countermeasures C1 and C2 are displayed: C1: Re-evaluate the pretreatment conditions; C2: Perform chemical cleaning on the reverse osmosis device. If at least one of the answers to Q4~Q6 is no, it is judged to be scale adhesion, and the following countermeasures D1 and D2 are displayed: D1: Re-evaluate the pH of the reverse osmosis water supply and double the amount of scale dispersant added; D2: Perform chemical cleaning on the reverse osmosis device. As described in item 6 of the patent application scope, the diagnostic device for the reverse osmosis system, wherein the pre-treatment device includes a coagulation treatment device and a filter membrane device for coagulation treatment water, and the operating status information further includes the sludge density index value of the filtered water of the filter membrane device.

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