JP2016161289A - Salt content measurement method and salt content measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a salinity content measurement method with which it is possible to simply and quickly obtain a salinity concentration contained in a sample solution, and a salinity content measurement device used in this measurement method.SOLUTION: Provided is a salinity content measurement method for measuring a salinity concentration contained in a sample solution S, the method being characterized by having the steps of: measuring the electrical conductivity E0 of the sample solution S; passing the sample solution S through a first filter F1 that collects first ions, obtaining a first filtrate having had the first ions removed, and measuring the electrical conductivity E1 of the first filtrate; and obtaining the concentration of first ions collected by the first filter F1 on the basis of a difference between the electrical conductivities E0 and E1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a salinity measuring method and a salinity measuring apparatus for a sample solution.

  The steel blades constituting the turbine blades and the rotor constituting the steam turbine are in an environment where drying and wetting are repeated in an operation involving rotation and stoppage. There is a risk that seawater leaks for various reasons and the salt content adheres to steel materials such as turbine blades, causing stress corrosion cracking (SCC) of the steel material, so it is necessary to control the density of salt content on the steel surface. .

Conventionally, a clean gauze was used to wipe the steel surface, and the sample solution obtained by collecting the salt attached to the gauze in purified water was analyzed with a chromatograph, and the salt density on the steel surface was examined (Sumiya method) ) However, it is usually difficult to bring a device for analyzing a small amount of salt collected in the sample solution to the site. Send the sample solution to an analysis room far away from the site and ask others to analyze it. It is common. Therefore, it is not uncommon for an analysis result to take one to two weeks. In this case, there is a problem that the judgment of the risk that SCC occurs is delayed. When the adhesion density of chloride ions exceeds the normal standard (for example, 10 mg / m ² ), it is necessary to perform a large-scale cleaning operation such as removing turbine blades from the rotor and washing with hot water. The delay in judging the sex hinders the resumption of steam turbine operation.

As an alternative to the smear method, for example, a surface deposit measuring device described in Patent Document 1 has been proposed. However, chloride ion (Cl ^-) To examine the concentration correctly, that there is a need to send the resulting sample solution for analysis chamber is the same as conventional smear method, rapid measurements in situ Difficult to get.

JP 2013-185911 A

  When the present inventors have examined based on the above background art, after the salt content adhering to the measurement surface of a predetermined area is dissolved in the sample solution by the conventional smear method or other methods, the ion concentration in the sample solution is determined. We thought that a simple and quick measurement method was necessary.

  This invention is made | formed in view of the said situation, Comprising: The salt content measuring method which can obtain the salt concentration contained in a sample liquid simply and rapidly, and the salt content measuring apparatus used for the measuring method are provided.

In order to solve the above problems, the present invention provides the following means.
A first aspect of the present invention is a salinity measuring method for measuring the concentration of salt contained in a sample solution,
Measuring the electrical conductivity E0 of the sample solution; passing the sample solution through a first filter that collects first ions; obtaining a first filtrate from which the first ions have been removed; Measuring the electrical conductivity E1 of one filtrate, and obtaining the concentration of the first ions collected in the first filter based on the difference between the electrical conductivities E0 and E1. It is a salinity measuring method characterized.

  According to the salinity measurement method of the first aspect, if a simple electric conductivity meter that can be carried and a first filter provided in the cartridge are prepared, the actual work is completed in a few minutes, so that it is included in the sample liquid S. The concentration of the first ion can be measured easily and rapidly. In order to obtain the concentration of the first ion and the concentration of the compound of the first ion from the difference (change amount) between the electric conductivity E0 and E1, the correspondence between the change amount of the electric conductivity and the change amount of the salinity concentration in advance. A calibration curve indicating the relationship may be prepared by a known method.

  In the second aspect of the present invention, the first filtrate is passed through a second filter that collects second ions to obtain a second filtrate from which the second ions have been removed. Further comprising the steps of measuring electrical conductivity E2 and obtaining the concentration of second ions collected by the second filter based on the difference between the electrical conductivities E1 and E2. It is the salt content measuring method as described in the first aspect.

  According to the salt content measurement method of the second aspect, the first ion and the second ion contained in the sample solution S can be separated and the concentration of each ion can be measured easily and rapidly. In order to obtain the concentration of the second ion and the concentration of the compound of the second ion from the difference (change amount) between the electrical conductivities E1 and E2, the change in the electrical conductivity and the change in the salinity concentration are previously determined. A calibration curve indicating the correspondence may be prepared by a known method.

  According to a third aspect of the present invention, the second filtrate is passed through a third filter that collects third ions to obtain a third filtrate from which the third ions have been removed. The step of measuring the electrical conductivity E3, and the step of obtaining the concentration of the third ions collected by the third filter based on the difference between the electrical conductivities E2 and E3, It is the salt content measuring method as described in a 2nd aspect.

  According to the salinity measurement method of the third aspect, the first ion, the second ion, and the third ion contained in the sample solution S can be separated, and the concentration of each ion can be measured easily and quickly. In order to obtain the concentration of the third ion and the concentration of the compound of the third ion from the difference (change amount) between the electrical conductivities E2 and E3, the change in the electrical conductivity and the change in the salinity concentration are previously determined. A calibration curve indicating the correspondence may be prepared by a known method.

  In a fourth aspect of the present invention, the first ion, the second ion, and the third ion are different from each other, and each ion is selected from the group consisting of a chloride ion, a sulfate ion, and a phosphate ion. It is any one sort of anion, It is a salt content measuring method as described in said 3rd aspect characterized by the above-mentioned.

  According to the salinity measurement method of the fourth aspect, chloride ions, sulfate ions, and phosphate ions, which are typical salinities contained in seawater, can be separated, and the concentration of each ion can be measured easily and quickly. it can.

  According to a fifth aspect of the present invention, the first ion, the second ion, and the third ion form different counter ions and precipitates in the first filter, the second filter, and the third filter, respectively. The salt content measuring method according to the third aspect or the fourth aspect, wherein the salt content is adsorbed by each filter.

  According to the salinity measurement method of the fifth aspect, each ion can be collected more reliably in each filter due to the formation of a precipitate, so that the accuracy of the salinity measurement result is improved.

  In the sixth aspect of the present invention, the counter ion of the first filter, the counter ion of the second filter, and the counter ion of the third filter are different counter ions, and each counter ion is a silver ion and a barium ion, respectively. And the salt content measuring method according to any one of the third to fifth aspects, wherein the cation is any one kind selected from the group consisting of calcium ions.

  According to the salinity measurement method of the sixth aspect, the first ions, the second ions, and the third ions that form and precipitate an ionic compound with each counter ion can be collected more reliably in each filter. The accuracy of the salinity measurement result is improved.

  The seventh aspect of the present invention is arranged such that the flow path for flowing the sample liquid in one direction and the sample liquid flowing in the one direction through the flow path pass in order, and the specific ion species in the sample liquid is One or more filters to be collected, and one or more inlet measurement units arranged on the inflow side of each of the one or more filters and measuring the electrical conductivity of the sample liquid immediately before flowing into each filter; , A salinity measuring apparatus provided with an outlet measuring unit that is disposed on the discharge side of the last filter through which the sample solution passes and measures the electrical conductivity of the sample solution discharged from the last filter.

  According to the salinity measuring apparatus of the seventh aspect, the work of passing the sample solution through the filter and the work of measuring the electrical conductivity before and after passing through the filter can be carried out efficiently. Moreover, since the device configuration is simple, it can be easily carried.

  The eighth aspect of the present invention is the filtration of the one or more filters so that the sample liquid flowing in one direction in the flow path passes through the one or more filters vertically upward or vertically downward. The salinity measuring apparatus according to the seventh aspect, wherein the surfaces are arranged horizontally.

In the salinity measuring apparatus according to the eighth aspect, when the sample liquid passes through the filter vertically upward, the sample liquid flowing in the flow channel comes into contact with the filtration surface of the filter arranged horizontally from below vertically, and the filter horizontal Since it diffuses in the direction and passes vertically upward, it can be filtered using the entire filtration surface of the filter and the entire filter.
In the salinity measurement apparatus according to the eighth aspect, when the sample liquid passes through the filter vertically downward, the sample liquid can naturally pass through the filter by its own weight. It can be distributed.

According to the salinity measurement method of the present invention, if a simple electric conductivity meter that can be carried and the first filter provided in the cartridge are prepared, the actual operation can be completed in a few minutes. The concentration of one ion can be measured easily and rapidly.
According to the salinity measuring apparatus of the present invention, it is possible to efficiently perform the work of passing the sample solution through the filter and the work of measuring the electrical conductivity before and after passing through the filter. Moreover, since the device configuration is simple, it can be easily carried.

It is a schematic block diagram of the salt content measuring apparatus 10 used in 1st embodiment of this invention. It is a schematic block diagram of the salt content measuring apparatus 20 used in 2nd embodiment of this invention. It is a schematic block diagram of the salt content measuring apparatus 30 used in 3rd embodiment of this invention. It is a schematic block diagram of the salt content measuring apparatus 40 used in 4th embodiment of this invention. It is a schematic block diagram of the salt content measuring apparatus 50 used in 5th embodiment of this invention. It is a schematic block diagram of the salt content measuring apparatus 60 used in 6th embodiment of this invention.

<First embodiment>
FIG. 1 is an example of a salinity measuring apparatus (hereinafter referred to as a measuring apparatus 10) applicable to the first embodiment of the salinity measuring method according to the present invention. The measuring apparatus 10 is arranged so that the water supply tank 1 for supplying the sample liquid S, the flow path 2 that circulates the sample liquid S in one direction, and the sample liquid S that flows in one direction through the flow path 2 pass in order. One or more filters F1, F2, F3 for collecting specific ionic species in the sample liquid S, and the sample liquid S immediately before flowing into each filter are arranged on the inflow side of each of the one or more filters. Samples discharged from the last filter F3 are arranged on the discharge side of the last filter F3 through which the sample liquid S passes and the cells C1, C2, C3 which are one or more inlet measurement units for measuring the electrical conductivity of This is a salinity measuring device 10 provided with a cell C4 which is an outlet measuring unit for measuring the electrical conductivity of the liquid S and a waste liquid tank 3 provided downstream of the flow path 2.

  In the measuring apparatus 10, each filter is a membrane type filter, and is arranged so that the filtration surface is substantially horizontal. With this arrangement, the sample liquid S flowing in one direction in the flow path 2 passes through each filter vertically upward. For example, when the sample liquid S flowing in the flow path 2 from the vertically lower side to the upper side of the filter F1 comes into contact with the center of the lower filtration surface of the disk-type membrane filter F1 provided in the cartridge 4, the resistance of the filtration surface The received sample liquid S spreads in the cartridge 4 in the circumferential direction of the membrane filter F1. Along with the spread in the horizontal direction, the sample liquid S passes through the filtration surface upward. As a result, the sample liquid S can be filtered using almost the entire surface and the entire membrane filter F1, which is preferable. A pump may be installed in the flow path 2 for the purpose of feeding the sample liquid S upward vertically. The same effect can be obtained when a cylindrical column filter is used instead of the membrane filter.

  The first embodiment of the salinity measuring method according to the present invention is a salinity measuring method for measuring the concentration of salinity contained in the sample liquid S using the measuring device 10, and measures the electrical conductivity E0 of the sample liquid S. And the sample solution S is passed through the first filter F1 that collects the first ions to obtain the first filtrate from which the first ions are removed, and the electrical conductivity E1 of the first filtrate is measured. And a step of obtaining the concentration of the first ions collected by the first filter F1 based on the difference between the electrical conductivities E0 and E1. The salt content measurement method of this embodiment may have a process of performing other treatments and measurements.

  The sample solution S in the present embodiment is an aqueous solution containing first ions, second ions, and third ions. When the sample liquid S is supplied to the water supply tank 1 and is pumped through the flow path 2, the sample liquid S flows into the first cell C <b> 1 arranged immediately before the cartridge 4. A pair of electrodes Y is provided in the first cell C1, and the electrical conductivity E0 of the sample solution S is measured by a known method. Subsequently, the sample liquid S flows into the cartridge 4, passes through the first filter F <b> 1 that collects the first ions, becomes the first filtrate from which the first ions are removed, and is discharged from the cartridge 4.

  When the liquid feeding in the flow path 2 is continued, the first filtrate flows into the second cell C2 disposed immediately before the cartridge 5. A pair of electrodes Y are provided in the second cell C2, and the electrical conductivity E1 of the first filtrate is measured by a known method. Next, the first filtrate flows into the cartridge 5, passes through the second filter F <b> 2 that collects the second ions, becomes a second filtrate from which the second ions are removed, and is discharged from the cartridge 5.

  When the liquid feeding in the flow path 2 is continued, the second filtrate flows into the third cell C3 disposed immediately before the cartridge 6. A pair of electrodes Y is provided in the third cell C3, and the electrical conductivity E2 of the second filtrate is measured by a known method. Next, the second filtrate flows into the cartridge 6, passes through the third filter F <b> 3 that collects the third ions, becomes the third filtrate from which the third ions are removed, and is discharged from the cartridge 6.

  If the liquid feeding in the flow path 2 is continued, the third filtrate flows into the fourth cell C4 arranged immediately after the cartridge 6. A pair of electrodes Y are provided in the fourth cell C4, and the electrical conductivity E3 of the third filtrate is measured by a known method. Next, the third filtrate is discharged from the fourth cell C4 and collected in the waste liquid tank 3.

  Based on the measured values of the electrical conductivities E0 to E3 obtained above, the concentrations of the first ions, second ions, and third ions collected by the filters F1, F2, and F3 are obtained. Specifically, it can be said that the difference between the electrical conductivity E1 and the electrical conductivity E0 is an amount that the first ions contribute to the conductivity of the sample liquid S. Therefore, the concentration of the first ions in the sample liquid S can be obtained by referring to a calibration curve prepared in advance by a known method and showing the relationship between the concentration of the first ions and the electrical conductivity. The concentration of the compound of the first ion is obtained in consideration of the molar ratio to the concentration of the first ion.

  Similarly, it can be said that the difference between the electrical conductivity E2 and the electrical conductivity E1 is an amount that the second ions contribute to the conductivity of the first filtrate. It can be said that the difference between the electrical conductivity E3 and the electrical conductivity E2 is an amount that the third ions contribute to the conductivity of the second filtrate. Therefore, the first filtrate is prepared by referring to each calibration curve prepared in advance by a known method and showing the relationship between the concentration of the second ion and the electric conductivity and the relationship between the concentration of the third ion and the electric conductivity. The concentration of the second ion in the solution and the concentration of the third ion in the second filtrate are obtained. Unless ions other than the specific ion species are collected in each filter, for example, unless unspecific ion collection in which the second ions are collected in the first filter F1, the ion concentration obtained above is It is the density | concentration of the 2nd ion in the sample liquid S, and the density | concentration of the 3rd ion. The concentration of the second ion compound and the third ion compound is obtained in consideration of the molar ratio of the second ion concentration to the third ion concentration.

In the present embodiment, the first ion, the second ion, and the third ion are different from each other, and each ion is a chloride ion (Cl ⁻ ), a sulfate ion (SO ₄ ²⁻ ), and a phosphate ion (PO). It is preferably any one kind of anion selected from the group consisting of ₄ ^3- ). Here, there are a total of six cases. The three types of ions constituting the group are representative anions contained in seawater.

  In the present embodiment, the first ion, the second ion, and the third ion are respectively formed in the first filter F1, the second filter F2, and the third filter F3 by forming different counter ions and precipitates. It is preferable to adsorb to. By forming the precipitate, each ion can be reliably collected in each filter.

Each counter ion of each filter F1, F2, F3 is a counter ion different from each other, and each counter ion is silver ion (Ag ⁺ ), barium ion (Ba ²⁺ ) and calcium ion (Ca ²⁺ ), respectively. The case where it is any one kind of cation chosen from the group which consists of is mentioned. There are six combinations of each filter and each counter cation.

As an example, for example, if the first filter F1 is a known Ba filter having barium ions, sulfate ions as the first ions contained in the sample liquid S form a barium sulfate precipitate and adsorb, and the Ba filter To be collected. When the second filter F2 is a known silver filter having silver ions, chloride ions as second ions contained in the first filtrate that has passed through the Ba filter are adsorbed by forming a silver chloride precipitate. Collected in silver filter. When the third filter F3 is a known Ca filter having calcium ions, the phosphate ions as the third ions contained in the second filtrate that has passed through the Ba filter and the silver filter are precipitates containing phosphoric acid (for example, Ca ₅ (PO ₄ ) OH, Ca ₃ (PO ₄ ) ₂ ) is formed and adsorbed and collected by the Ca filter.

  Therefore, in the case of the above example, each concentration of sulfate ion, chloride ion, and phosphate ion in the sample solution S can be obtained by the above-described measurement of electrical conductivity.

The type of the sample liquid S is not particularly limited. For example, the sample liquid S obtained by the smear method may be used for the purpose of examining the salt adhesion density attached to the steam turbine blade and its rotor.
For example, a sample containing sulfate ions, chloride ions and phosphate ions adhering to the measurement area by immersing gauze carefully wiped from the measurement area of a predetermined area on the steel surface of the turbine blade in purified water It can be set as the liquid S. Based on the concentration of each ion obtained by the salt content measurement method of the present embodiment, the adhesion density of each ion constituting the salt content adhered to the measurement region on the steel material surface can be calculated. Further, the concentration of the compound of each ion and the adhesion density are calculated from the relationship of the molar ratio between each ion and each ionic compound.

<Second embodiment>
FIG. 2 is an example of a salinity measuring apparatus (hereinafter referred to as a measuring apparatus 20) applicable to the second embodiment of the salinity measuring method according to the present invention. The components common to the measurement device 20 and the measurement device 10 of the first embodiment are denoted by common reference numerals.

The first filter F1 of the present embodiment is a known Ba filter having barium ions. When the sample liquid S is supplied to the water supply tank 1 and is pumped through the flow path 2, the sample liquid S flows into the first cell C <b> 1 arranged immediately before the cartridge 4. A pair of electrodes Y is provided in the first cell C1, and the electrical conductivity E0 of the sample solution S is measured by a known method.
Subsequently, the sample solution S flows into the cartridge 4, and sulfate ions as the first ions contained in the sample solution S form a barium sulfate precipitate and are adsorbed and collected by the Ba filter.
The first filtrate from which sulfate ions have been removed is discharged from the cartridge 4.

  When the liquid feeding in the flow path 2 is continued, the first filtrate flows into the second cell C <b> 2 arranged immediately after the cartridge 4. In the second cell C2, the electrical conductivity E1 of the first filtrate is measured by a known method. Next, the first filtrate is discharged from the second cell C <b> 2 and collected in the waste liquid tank 3.

Based on the measured values of the electrical conductivity E0 and the electrical conductivity E1 measured as described above, a calibration curve prepared in advance for the concentration of sulfate ions collected in the Ba filter, that is, the concentration of sulfate ions contained in the sample solution S, is obtained. Seek and ask. When sulfate ions constitute sodium sulfate (Na ₂ SO ₄ ) in the sample solution, the molar concentration of sodium ions in the sample solution is twice the molar concentration of sulfate ions.

<Third embodiment>
FIG. 3 is an example of a salinity measuring apparatus (hereinafter referred to as a measuring apparatus 30) applicable to the third embodiment of the salinity measuring method according to the present invention. The components common to the measurement device 30 and the measurement device 10 of the first embodiment are denoted by common reference numerals.

The second filter F2 of this embodiment is a known silver filter having silver ions. When the sample liquid S is supplied to the water supply tank 1 and is pumped through the flow path 2, the sample liquid S flows into the second cell C <b> 2 arranged immediately before the cartridge 5. A pair of electrodes Y are provided in the second cell C2, and the electrical conductivity E0 of the sample solution S is measured by a known method.
Subsequently, the sample liquid S flows into the cartridge 5, and chloride ions as second ions contained in the sample liquid S form a silver chloride precipitate and are adsorbed and collected by the silver filter.
The second filtrate from which chloride ions have been removed is discharged from the cartridge 5.

  When the liquid feeding in the flow path 2 is continued, the second filtrate flows into the third cell C3 arranged immediately after the cartridge 5. In the third cell C3, the electric conductivity E2 of the second filtrate is measured by a known method. Next, the second filtrate is discharged from the third cell C3 and collected in the waste liquid tank 3.

  Based on the difference between the electrical conductivity E0 and the electrical conductivity E2 measured above, the calibration curve prepared in advance for the concentration of chloride ions collected in the silver filter, that is, the concentration of chloride ions contained in the sample solution S Seek to find out. When chloride ions constitute sodium chloride (NaCl) in the sample solution, the molar concentration of sodium ions in the sample solution is the same as the molar concentration of chloride ions.

<Fourth embodiment>
FIG. 4 is an example of a salinity measuring apparatus (hereinafter referred to as a measuring apparatus 40) applicable to the fourth embodiment of the salinity measuring method according to the present invention. The components common to the measurement device 40 and the measurement device 10 of the first embodiment are denoted by common reference numerals.

The third filter F3 of this embodiment is a known Ca filter having calcium ions. When the sample liquid S is supplied to the water supply tank 1 and fed through the flow path 2 by a pump, the sample liquid S flows into the third cell C3 disposed immediately before the cartridge 6. A pair of electrodes Y are provided in the third cell C3, and the electrical conductivity E0 of the sample solution S is measured by a known method.
Subsequently, the sample solution S flows into the cartridge 6, and phosphate ions as third ions contained in the sample solution S are precipitates such as Ca ₅ (PO ₄ ) OH, Ca ₃ (PO ₄ ) _{2, and the} like. Is adsorbed and collected by the Ca filter.
The third filtrate from which phosphate ions have been removed is discharged from the cartridge 6.

  If the liquid feeding in the flow path 2 is continued, the third filtrate flows into the fourth cell C4 arranged immediately after the cartridge 6. In the fourth cell C4, the electrical conductivity E3 of the third filtrate is measured by a known method. Next, the third filtrate is discharged from the fourth cell C4 and collected in the waste liquid tank 3.

A calibration curve prepared in advance based on the difference between the electrical conductivity E0 and the electrical conductivity E3 measured above, and the concentration of phosphate ions collected in the Ca filter, that is, the phosphate ion concentration contained in the sample solution S. Seek to find out. When phosphate ions constitute trisodium phosphate (Na ₃ PO ₄ ) in the sample solution, the molar concentration of sodium ions is three times the molar concentration of phosphate ions.

<Fifth embodiment>
FIG. 5 is an example of a salinity measuring apparatus (hereinafter referred to as a measuring apparatus 50) applicable to the fifth embodiment of the salinity measuring method according to the present invention. The components common to the measurement device 50 and the measurement device 10 of the first embodiment are denoted by common reference numerals.

  In the measuring device 50, each of the filters F1, F2, and F3 is a membrane type filter and is disposed so that the filtration surface is substantially horizontal. With this arrangement, the sample liquid S flowing in one direction in the flow channel 2 passes through each filter vertically downward. For example, when the sample liquid S flowing in the flow path 2 from vertically above the filter F3 comes into contact with the center of the upper filtration surface of the disk-type membrane filter F3 provided in the cartridge 6, the sample naturally grows by its own weight. The liquid S passes through the filtration surface downward. Similarly, the sample liquid S naturally passes through the filters F2 and F1 and is collected in the waste liquid tank 3 by its own weight. Therefore, even if a pump for feeding the sample liquid S is not installed in the flow path 2, the sample liquid S can flow in one direction of the flow path 2, that is, downward. Since the measuring device 50 is reduced in size and weight because it is not necessary to provide the pump and its power source, it is easier to use the measuring device 50 outdoors or to carry it to the site easily.

  The third filter F3 of the present embodiment is a Ca filter, the second filter F2 is a silver filter, and the first filter F1 is a Ba filter. When the sample liquid S sequentially passes through the filters F3, F2, and F1, phosphate ions, chloride ions, and sulfate ions contained in the sample liquid S are collected. The electric conductivity E0 to E4 is measured by the cells C4, C3, C2, and C1 arranged before and after each filter, and the change in the electric conductivity before and after passing through each filter is collected by each filter. The amount of ions obtained is determined according to a calibration curve.

<Sixth embodiment>
FIG. 6 is an example of a salinity measuring apparatus (hereinafter referred to as a measuring apparatus 60) applicable to the sixth embodiment of the salinity measuring method according to the present invention. Components common to the measurement device 60 and the measurement device 10 of the first embodiment are denoted by common reference numerals.

In the present embodiment, a Ba filter as the first filter F1 and a Ca filter as the third filter F3 are stacked in a single cartridge 7 via a separator.
When the sample liquid S of the measuring device 60 is supplied to the water supply tank 1 and is pumped through the flow path 2, the sample liquid S flows into the first cell C <b> 1 disposed immediately before the cartridge 7. A pair of electrodes Y is provided in the first cell C1, and the electrical conductivity E0 of the sample solution S is measured by a known method.
Subsequently, the sample liquid S flows into the cartridge 7, and sulfate ions as the first ions contained in the sample liquid S form a precipitate and are collected while passing through the Ba filter. Furthermore, while the filtrate passing through the separator passes through the Ca filter, phosphate ions as third ions contained in the filtrate form a precipitate and are collected. The filtrate that has passed through the Ca filter is discharged out of the cartridge 7.

  When the liquid feeding in the flow path 2 is continued, the filtrate flows into the second cell C2 arranged immediately after the cartridge 7. In the second cell C2, the electrical conductivity E1 of the filtrate is measured by a known method. Next, the filtrate is discharged from the second cell C <b> 2 and collected in the waste liquid tank 3.

  Based on the measured values of electrical conductivity E0 and electrical conductivity E1 measured as described above, the concentration of both sulfate ions and phosphate ions collected by the Ba filter and Ca filter, ie, the sample solution S is included. The concentration of both sulfate ions and phosphate ions is determined with reference to a calibration curve prepared in advance.

  As mentioned above, although the embodiment of the salinity measuring method and the salinity measuring apparatus of the present invention has been described, the present invention is not limited to the above embodiment, and can be appropriately changed without departing from the spirit of the present invention. Moreover, it is possible to replace the constituent elements in the above-described embodiments with known constituent elements as appropriate.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

[Example 1]
(Preparation of sample solution)
Using 1 to 10 g of cotton gauze containing purified water, the measurement area of about 200 cm ² of the steel surface of the turbine blade suspected of having salt from seawater adhered thereto was wiped off. When wiping off, workers wore salt-free rubber gloves.
The wiped gauze was immersed in 50 ml of purified water in a beaker and heated with a heater at 100 ° C. for 30 minutes with the lid closed to prevent evaporation. After cooling to room temperature, the gauze was taken out, the gauze was squeezed, and the purified water taken out by the gauze was returned to the beaker. Next, the gauze after squeezing was immersed in 50 ml of purified water in another beaker, and the series of steps of heating, cooling, and squeezing was further repeated twice. Thereby, the sample liquid S which dissolved the salt content wiped off with the gauze in a total of 150 ml of purified water was obtained.

Using the measuring apparatus 10 of FIG. 1, the sample liquid S was injected into the water supply tank 1 and pumped in the flow path 2 in order.
In the commercially available Ba filter (Tech Jam, Agilent, Thermo, etc.) that is the first filter F1, sulfate ions are generated by the reaction of Na ₂ SO ₄ + Ba ²⁺ → BaSO ₄ (precipitation) + Na ^+. It was collected.
In a commercially available silver filter (Tech Jam, Agilent, Thermo, etc.) as the second filter F2, chloride ions were collected by the reaction of NaCl + Ag ⁺ → AgCl (precipitation) + Na ⁺ .
In the commercially available Ca filter (manufactured by Techjam, Agilent, Thermo, etc.) as the third filter F3, phosphorous is obtained by the reaction of 2Na ₃ PO ₄ + 3Ca ²⁺ → Ca ₃ (PO ₄ ) ₂ + 6Na ^+. Acid ions were collected.

From the difference (E0-E1) in the electrical conductivity (unit: mS / m) measured in the first cell C1 and the second cell C2, the sulfate ion concentration in the sample solution S is 0.20 mg / It turned out to be L.
From the difference (E1-E2) in electrical conductivity (unit: mS / m) measured in the second cell C2 and the third cell C3, the chloride ion concentration in the sample solution S is 0.60 mg with reference to the calibration curve. It turned out to be / L.
From the difference (E2-E3) in electrical conductivity (unit: mS / m) measured in the third cell C3 and the fourth cell C4, the phosphate ion concentration in the sample solution S is 0.16 mg with reference to the calibration curve. It turned out to be / L.

From the above results, the salt adhesion density in the measurement region (200 cm ² ) on the surface of the steel material to which each ion contained in the sample liquid S was adhered was Na ₂ SO ₄ = 10 mg / m ² ; NaCl = 30 mg / m, respectively. ² ; found to be Na ₃ PO ₄ = 8 mg / m ² .

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, each structure and those combination in each embodiment are examples, and addition of a well-known structure is within the range which does not deviate from the meaning of this invention. , Omissions, substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

  The present invention can be widely used in the field of using steel materials such as turbines and ships.

10, 20, 30, 40, 50, 60 ... measuring device, 1 ... water supply tank, 2 ... flow path, 3 ... waste liquid tank, 4, 5, 6, 7 ... cartridge, F1 ... first filter, F2 ... second Filter, F3 ... Third filter, F4 ... Fourth filter, C1 ... First cell, C2 ... Second cell, C3 ... Third cell, C4 ... Fourth cell, S ... Sample solution, Y ... Electrode

Claims (8)

A salinity measuring method for measuring the concentration of salinity contained in a sample solution,
Measuring the electrical conductivity E0 of the sample solution;
Passing the sample solution through a first filter that collects first ions, obtaining a first filtrate from which the first ions have been removed, and measuring an electrical conductivity E1 of the first filtrate;
Obtaining the concentration of the first ions collected in the first filter based on the difference between the electrical conductivity E0 and E1, and
A salinity measuring method characterized by comprising: Passing the first filtrate through a second filter that collects second ions, obtaining a second filtrate from which the second ions have been removed, and measuring the electrical conductivity E2 of the second filtrate. When,
Obtaining a concentration of second ions collected in the second filter based on the difference between the electrical conductivity E1 and E2,
The salt content measuring method according to claim 1, further comprising: Passing the second filtrate through a third filter for collecting third ions, obtaining a third filtrate from which the third ions have been removed, and measuring the electrical conductivity E3 of the third filtrate When,
Obtaining a concentration of third ions collected in the third filter based on the difference between the electrical conductivity E2 and E3,
The salt content measuring method according to claim 2, further comprising:   The first ion, the second ion, and the third ion are different from each other, and each ion is any one anion selected from the group consisting of chloride ion, sulfate ion, and phosphate ion. The salinity measurement method according to claim 3.   The first ion, the second ion, and the third ion are adsorbed on each filter by forming different counter ions and precipitates in the first filter, the second filter, and the third filter, respectively. The salinity measuring method according to claim 3 or 4, characterized in that   The counter ion of the first filter, the counter ion of the second filter, and the counter ion of the third filter are different counter ions, and each counter ion is selected from the group consisting of silver ion, barium ion and calcium ion, respectively. The salt content measuring method according to any one of claims 3 to 5, wherein the salt content is any one kind of cation. A flow path through which the sample liquid flows in one direction;
One or more filters that are arranged so that the sample liquid flowing in one direction through the channel sequentially passes, and that collects specific ion species in the sample liquid;
One or more inlet measurement units arranged on the inflow side of each of the one or more filters and measuring the electrical conductivity of the sample solution immediately before flowing into the filters;
An outlet measuring unit that is disposed on the discharge side of the last filter through which the sample solution passes and measures the electrical conductivity of the sample solution discharged from the last filter;
A salinity measuring device equipped with   The filtration surface of the one or more filters is horizontally arranged so that the sample liquid flowing in one direction in the flow path passes through the one or more filters vertically upward or vertically downward. The salinity measuring apparatus according to claim 7.

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