JP2023070174A - Total organic carbon measuring device - Google Patents

Abstract

To provide a measuring device that does not need a gas-liquid separation device, a degasifier, and a scrubber device for preventing corrosive gas, can measure the amount of CO2 gas without being affected by ionized substance under a high conductivity (in a solution densely containing ionizable substance such as sodium other than organic materials) which is impossible when a conductivity manner is used, and can measure the total organic carbon amount in the measurement solution on a business level.SOLUTION: The total organic carbon measuring device includes: an oxidation chamber for forming an oxidized measurement solution by irradiating a measurement solution with ultraviolet rays from an ultraviolet rays supply source or burning an organic material in the measurement solution under a high-temperature and high-pressure condition; and a DCO2 detector for detecting the amount of CO2 in the solution in at least one of the side of supplying the measurement solution into the oxidation chamber and the side of discharging the oxidized measurement solution from the oxidation chamber.SELECTED DRAWING: Figure 1-2

Description

The present invention relates to the measurement of the total organic carbon (hereinafter sometimes referred to as TOC) contained in the water to be measured, and more specifically, the total amount of _CO2 dissolved in the water to be measured can be directly measured. It relates to an organic carbon measuring device.

A total organic carbon measuring device, a so-called TOC meter, is used to measure the state of water pollution caused by organic substances. In such an apparatus, the degree of contamination is represented by the amount of carbon in the organic substances present in the water. However, since it is not possible to directly measure the amount of organic carbon in water, it is a method of forcibly oxidizing organic matter in the water to be measured to convert it to carbon dioxide (CO ₂ ) and then determining the amount of total organic carbon (TOC). is commonly used.

TOC meters used for such measurements employ several types of methods as shown below.
For example, there is a high-temperature combustion TOC meter (high-temperature combustion/NDIR: CO ₂ analysis) 30 with a configuration diagram in FIG. By injecting the measurement solution into the furnace 31 (heat source: heater H) and burning the entire solution containing organic matter at a high temperature (for example, about 800 ° C.), the moisture is instantly evaporated, and the organic matter varies depending on the type. In this method, the fuel is combusted with a delay of about 2 minutes to change into water and CO ₂ (carbon dioxide gas), and the amount of CO ₂ is analyzed by a non-diffusion infrared analyzer (NDIR) 32 . In FIG. 3(a), 33 is a gas-liquid separator, 34 is a dehumidifier, 35 is a scrubber, 36 is an aerator (IC remover by _N2 gas purge), 37 is a measuring solution injector, and P1 and P2 are operating pumps. is.

In addition, the wet oxidation TOC meter (decomposition of organic matter by UV/NDIR: CO ₂ analysis) 40, whose configuration diagram is shown in FIG. It is the same as the above-mentioned high-temperature combustion type TOC analyzer, but instead of high-temperature combustion, UV (ultraviolet) is used as a method of burning organic matter, and the energy of ultraviolet rays is used to decompose organic matter without raising the temperature (oxidation chamber 41 from the combustion furnace to the UV chamber). However, a UV lamp is used to irradiate the solution with UV (ultraviolet rays), but unlike a general germicidal UV fluorescent lamp, it is necessary to use a lamp with a very short wavelength of 185 nm, which has large energy. In FIG. 4(a), 43 is a gas-liquid separator, 44 is a dehumidifier, 45 is a scrubber, 46 is an aerator (IC remover by _N2 gas purge), and P1 and P2 are operating pumps.

In the method using NDIR 32 and 42 described in FIGS. 3 and 4 above, CO ₂ gas is extracted from the liquid/gas state (or mixture) and NDIR (non-diffusion infrared spectrometer, for example, see FIG. 7(a)) ), but the method for extracting _CO2 gas is a gas-liquid separator (see, for example, Fig. 7 (b)), a degassing device, and a scrubber device for preventing corrosive gas (for example, Fig. 7 (c )) are necessary equipment for NDIR because corrosive gases and moisture cause deterioration and measurement errors.
In addition, it is necessary to remove CO ₂ (carbon dioxide gas) contained in the measurement solution from the beginning, so that the pH of the measurement solution is adjusted to about 2 and incidental equipment is introduced to remove CO ₂ (carbon dioxide gas) by aeration or the like. Problems such as maintenance associated with this and influence on measured values will occur.

Furthermore, the UV oxidation/conductivity TOC meter (UV oxidation/conductivity measurement) 50, whose configuration is shown in FIG. It uses rate meters 58a and 58b (see, for example, FIG. 5(a)), and its principle is that CO ₂ (carbon dioxide gas) produced by oxidation by UV irradiation (UVp) in the oxidation chamber 51 is In this method, the amount of ionized CO ₂ (carbon dioxide gas) is proportional to the electrical conductivity, so the amount of CO ₂ (carbon dioxide gas) is obtained from the electrical conductivity.

This conductivity method uses a method in which the conductivity before oxidation is first measured and compared with the conductivity after oxidation.
However, as a drawback, unlike the NDIR method, it does not require a device such as a gas-liquid separator because it directly measures the conductivity in a solution. becomes higher than the conductivity of CO ₂ (carbon dioxide gas), resulting in a large measurement error. Therefore, water quality equal to or higher than that of distilled water is usually required, and the scope of use is limited to pure water used in semiconductor factories, pharmaceuticals, and the like.

In view of the drawbacks of this conductivity method, in the wet oxidation/conductivity method TOC meter 60 shown in _FIG . gas) is dissolved in ultrapure water made by a small ultrapure water device 62 whose configuration diagram _is shown in FIG. is measured with a conductivity meter (see FIG. 6(b), reference numeral 58a, incorporated in the ultrapure water device 62), and then the CO ₂ (carbon dioxide gas) generated by oxidation is measured once through the thin film 68b through and dissolved in ultrapure water made by a small ultrapure water device 62 whose configuration diagram is _shown in FIG. By the method of measuring with a conductivity meter (see FIG. 6(b), reference numeral 58b, incorporated in the ultrapure water device 62), ions contained in the measurement solution Ls and causing errors in measurement can be removed, so high Conductivity can also be measured, but it requires an ultrapure water system, and since it is a conductivity method, it has the disadvantages of increasing the measurement error for high-concentration organic substances. Reference numeral 63 is an ion exchange resin, and P1 and P2 are pumps.

Thus, the conventional total organic carbon measuring device (TOC meter) for measuring organic matter in water consists of removing _CO2 contained in the water to be measured, oxidizing the organic matter to _CO2 , and separating _CO2 . The process of measuring CO2 and the process of measuring _CO2 are necessary, but in these complicated processes, the present application attempts to improve measurement accuracy, reduce costs, and simplify maintenance by simplifying these processes without degrading performance. It is.

In view of this situation, the conventional total organic carbon measuring device (TOC meter) for measuring organic matter in water has problems such as its complicated structure or narrow range of gas supply and measurement conditions. Since the basic principle is to extract and measure _CO2 gas generated from oxidized organic matter, a mechanism for extracting _CO2 gas from water and ancillary facilities such as carrier gas supply for gas analysis are required. Furthermore, due to the structure of the NDIR (non-diffusive infrared spectrometer), moisture and corrosive gases contained in CO ₂ cause measurement errors, and NDIR corrodes and deteriorates, so dehumidifiers and scrubbers are required. , the resulting complication hindered price reduction.

Therefore, in the present invention, if a detector (sensor) is directly installed in an aqueous solution containing CO ₂ gas, and the amount of CO ₂ gas can be directly measured, a "gas-liquid separator", a "deaerator", and a "corrosive gas It eliminates the need for a scrubber device for prevention, and even with high conductivity (solutions with high concentration of ionizing substances such as sodium other than organic substances), which was impossible with the conductivity method, ionization To provide a measuring device capable of measuring the amount of CO ₂ gas without being affected by substances and measuring the total amount of organic carbon in a solution to be measured at a practical level.

That is, the first aspect of the present invention for solving the above problems is to irradiate the measurement solution with ultraviolet rays from an ultraviolet source or burn the organic matter contained in the measurement solution under high temperature and high pressure conditions to measure the oxidized state. Dissolved carbon dioxide gas (dissolved CO ₂ , DCO ₂ (Dissolved CO ₂ )) (also referred to as "dissolved carbon detector" or "DCO ₂ detector").

In a second aspect of the present invention, an oxidizing agent for adjusting the pH of the measurement solution is introduced into the measurement solution on the upstream side of the DCO ₂ detector on the side of supplying the measurement solution to the oxidation chamber in the first aspect. The total organic carbon measuring device is characterized by comprising a pH adjusting section for controlling the pH.

A third aspect of the present invention is a total organic carbon measuring device characterized in that the UV source in the first aspect is an ultraviolet lamp (UV lamp) or an excimer lamp.

In a fourth aspect of the present invention, the measuring solution whose _CO2 amount is detected by the _DCO2 detector on the side supplying the measuring solution to the oxidation chamber in the first aspect is adjusted to have a pH of 2. The total organic carbon measuring device is characterized in that In addition, _the dissolved carbon dioxide gas in the solution changes to carbonate H ₂ CO ₃ , bicarbonate ion HCO ^3- _, and carbonate ion CO ₃ ^2- depending on the pH of the solution. This is the reason why the pH must be about 2 or less, and the pH of the DCO ₂ detector of this TOC meter must be maintained at about 2 as well.

A fifth aspect of the present invention is that the detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement solution in the first aspect is formed by the CO ₂ absorbed by the measurement solution or the oxidized measurement solution. CO ₂ is taken into the permeable membrane and detected directly inside the membrane with mid-infrared rays, but in order to enable continuous measurement, the CO ₂ in the permeable membrane is separated from the solution by obtaining a permeable membrane that can enter and exit freely. after obtaining CO ₂ gas by means of the detector, quantitative analysis is performed using the mid-infrared absorbance of the CO ₂ gas.

A sixth aspect of the present invention is that the detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement solution in the first aspect is formed by the CO ₂ absorbed by the measurement solution or the oxidized measurement solution. CO ₂ is taken _into the permeable membrane and detected directly inside the membrane with mid-infrared rays. Second, the CO ₂ gas that has passed through the permeable membrane and exited outside the permeable membrane is discharged to the outside of the device and not used for measurement, and the CO ₂ gas contained in the permeable membrane is absorbed by mid-infrared rays. It is a total organic carbon measuring device characterized by being carried out by the detector that quantitatively analyzes using a degree.

A seventh aspect of the present invention is that the detection of the amount of CO ₂ in the measurement solution or the oxidized measurement solution in the first aspect is formed by CO ₂ contained in the measurement solution or the oxidized measurement solution CO ₂ is transferred from the measurement solution or oxidized measurement solution side to obtain a composite film composed of the order of reflector/CO ₂ permeable film/protective member or the order of CO ₂ permeable film/reflector, and the permeable The _CO2 gas that permeates the membrane and is discharged to the outside is not used for measurement _. The _CO2 gas inside the permeable membrane makes the mid-infrared The total organic carbon measuring apparatus is characterized in that the detector performs quantitative analysis using mid-infrared absorbance of CO ₂ gas whose sensitivity is increased by increasing the absorbance of infrared light.

In an eighth aspect of the present invention, the detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement solution in the first aspect is formed by CO ₂ contained in the measurement solution or the oxidized measurement solution. A total organic carbon measuring apparatus characterized in that CO ₂ is separated by a permeable membrane to obtain CO ₂ gas by the detector, and the obtained CO ₂ gas is quantitatively analyzed with mid-infrared rays.

In a ninth aspect of the present invention, the DCO ₂ detector according to the first aspect has a liquid inlet on one end and a liquid outlet and a detector installation site on the other end. , and is installed at the installation site of the detector of the detector chamber, which is provided inside the housing and consists of a helical liquid guide plate provided from the inlet to the contact site between the detector and the liquid. The total organic carbon measuring device is characterized in that
In a tenth aspect of the present invention, bubbles formed by vaporization _of CO 2 dissolved in the measurement solution or oxidized measurement solution in the first aspect are converted into dissolved CO ₂ in the measurement solution or oxidized measurement solution. conversion is performed using a gas-liquid two-phase flow mixer.

ADVANTAGE OF THE INVENTION According to this invention, there exists an effect shown below.
1. Direct measurement of the amount of _CO2 in the measured solution eliminates the need for conventional gas-liquid separators and dehumidifiers as well as scrubbers to remove corrosive gases.
2. It has the advantage over the wet oxidation method that it does not require a carrier gas such as nitrogen gas.
3. It is now possible to measure high-conductivity solutions, which was a drawback of the UV oxidation method.
4. It is also possible to measure solutions with high concentrations of total organic carbon, which was a drawback of the wet oxidation method.
5. There are few restrictions on the solutions used for measurement.
6. An aerator, which was required to remove inorganic carbon (IC) from the measurement solution, is no longer necessary.
7. Aeration eliminates the disappearance of volatile organics, which was a source of error.
8. It is possible to eliminate measurement errors during "conductivity measurement of sample water", and improvement of measurement accuracy can be expected.
9. It is possible to eliminate the conversion error that occurs during "conductivity/ _CO2 conversion", and an improvement in measurement accuracy can be expected.
10. Online measurement is possible, and water quality control based on the measurement results is possible.

1 is a schematic configuration diagram of an example of a total organic carbon measuring device according to the present invention; FIG. FIG. 2 is a schematic configuration diagram of another example of the total organic carbon measuring device according to the present invention; BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the detector based on this invention, (a) is a schematic diagram which shows an example of schematic structure of _DCO2 detector (1a, 1b) based on embodiment of this invention. It is a specific schematic configuration diagram of the detector according to the present invention, (b) and (c) are schematic diagrams showing an example of the schematic structure of the DCO ₂ detector (1a, 1b) according to the embodiment of the present invention, (b) shows the basic structure, and (c) is a schematic structure used to further increase the detection sensitivity, which is an application of the light integration structure. FIG. 2D is a specific schematic configuration diagram of the DCO ₂ detector according to the present invention, and (d) is a schematic structural diagram showing another embodiment. FIG. 2 is a specific schematic configuration diagram of a DCO ₂ detector according to the present invention, where (e) is a schematic structural diagram showing another embodiment, and (f) is a photograph of the external appearance. It is a conventional high temperature combustion TOC meter (high temperature combustion/NDIR: _CO2 analysis). (a) is a block diagram, (b) is an external photograph, and (c) is an internal photograph. It is a wet oxidation type TOC meter (decomposition of organic matter by UV/NDIR: _CO2 analysis). (a) is a block diagram, (b) is an external photograph, and (c) is an internal photograph. It is a wet oxidation/conductivity TOC meter (wet oxidation/conductivity measurement). (a) is a configuration diagram, and (b) is an internal photograph. This is a wet oxidation/conductivity TOC meter (wet oxidation/conductivity measurement) of a different form from that of FIG. (a) is a configuration diagram, and (b) is a configuration diagram of an ultrapure water device. (a) is an NDIR device, (b) is an incidental facility (gas-liquid separator), and (c) is an internal photograph of an incidental facility (scrubber device).

The total organic carbon measuring device according to this embodiment will be described in detail below.
It should be noted that the present invention is not limited to the contents in the following description, and can include various modifications and alternative examples without departing from the scope of the present invention.

FIGS. 1-1 and 1-2 are one example and another example of a schematic configuration diagram of a total organic carbon measuring device according to the present invention, wherein 10A and 10B are total organic carbon measuring devices according to the present invention, 2 is an oxidation chamber, UVp is an ultraviolet supply source (UV lamp), 4 is a measurement solution storage tank, 5 is a drain port, 6 is a pipe, 7 is an oxidant (Ox) supply source, 7a is an oxidant input position, and 8 is a gas-liquid two-phase. Flow mixer, P1, P2 are operating pumps, 1a is the inlet side DCO ₂ detector of the oxidation chamber 2, 1b is the outlet side DCO ₂ detector of the oxidation chamber 2. Although not shown, a control/measuring unit for controlling the operation, measurement, etc. of the measuring apparatus 10 is provided.

The difference in the features of the total organic carbon measuring apparatuses 10A and 10B according to the present invention is that, first, both of them are of a system in which CO ₂ is taken into a permeable film and detected directly by mid-infrared rays, but the total organic carbon measuring apparatus 10B In order to enable continuous measurement and avoid the influence of the CO ₂ gas in the permeable membrane that has passed through the permeable membrane and exited the permeable membrane, the CO ₂ gas passes through the permeable membrane and the permeable It is possible to separate the CO ₂ gas that has come out of the membrane by discharging it to the outside of the total organic carbon measurement device, and to avoid the influence of the CO ₂ gas that has come out of this permeable membrane on the infrared measurement. After obtaining the CO ₂ gas present in the permeable membrane, the DCO ₂ detector performs a quantitative analysis using the mid-infrared absorbance of the CO ₂ gas.
Furthermore, secondly, in the process of oxidizing organic matter to CO ₂ in the present invention, when a high concentration of organic matter is oxidized, part of the "dissolved carbon dioxide gas" gasifies into "bubbles" and "gas-liquid two A “phase flow” may occur. Therefore, in the total organic carbon measuring apparatus according to the present invention using a dissolved carbon dioxide detector, bubbling CO ₂ may cause measurement errors. As in the organic carbon measurement device 10B, a "gas-liquid two-phase flow mixer (code 8)" is installed on the downstream side of the oxidation chamber 2 and used, so that CO ₂ components that are gasified and become bubbles The point is that a method of dissolving is used. It goes without saying that this second difference can also be applied to the total organic carbon measuring apparatus 10A according to the present invention.

FIG. 2-1(a) is a schematic structural diagram showing an example of a DCO ₂ detector (indicated by symbols 1a and 1b in FIG. 1) used in the present invention.
Dissolved CO ₂ in the measurement solution is taken into the permeable membrane 21 by contact with the CO ₂ permeable membrane 21 which is the contact portion with the measuring solution Ls ^B or the oxidized measuring solution Ls ^A , and Mid-infrared rays are irradiated, and the amount of mid-infrared absorption proportional to the CO ₂ concentration of the mid-infrared rays in the CO ₂ permeable film 21 is detected and measured (absorbance measurement) by the photodetector 23 . Furthermore, the protective member 25 is made of glass that is impermeable to CO ₂ gas and is permeable to mid-infrared rays, such as “sapphire glass”.

As the CO ₂ permeable membrane 21 shown in FIG. 2-1(a), a membrane is used that allows CO ₂ gas to permeate bidirectionally between the surface in contact with the measurement solution and the opposite surface. In addition, detection and measurement do not involve consumption of CO ₂ , so there is an advantage that measurement errors can be eliminated.

Another example of the embodiment of the present invention uses detectors 1a and 1b as shown in FIG. 2-2(b).
The DCO ₂ detector shown in Fig. 2-1(a) is a method for directly measuring CO ₂ in a solution that absorbs CO ₂ on the surface of a film that has absorbed CO ₂ from the degree of attenuation using mid-infrared rays. However, when aiming for detection with higher sensitivity, mid-infrared rays are transmitted through the CO ₂ adsorption thick film 27 (see FIG. 2-2(b)), and returned mid-infrared rays are emitted by the gold-plated reflector 26 on the opposite side. passes through the adsorption thick film 27 again and then is guided to the photodetector 23, so that a larger amount of attenuation due to CO ₂ can be obtained.
The sapphire glass (protective member) 25 used is permeable to mid-infrared rays, but plays a role in preventing CO ₂ and water vapor from leaking from the measurement solution side to the electric system. The gold-plated punching plate of the reflecting plate 26 is a plate with small holes 26a for CO ₂ entry and exit, and the purpose is to allow CO ₂ to enter and exit the CO ₂ adsorption thick film 27 and to maintain the thick film. If the total area of the holes is large, the reflective surface will be reduced, so it is necessary to suppress the area of the holes to about 30 to 40% of the total area.
There is an efficiency difference of 10 to 100 times or more between CO ₂ absorption due to reflection on the surface of the CO ₂ adsorbent and transmission absorption.

Another example of the embodiment of the present invention uses a detection device in which a detector chamber 28 of a housing and a detector are combined as shown in FIG. 2-2(c). This ^device improves the detection efficiency of the DCO ₂ detectors 1a and ^1b _. A detector chamber 28 is provided so as to cover the contact site S (the area surrounded by the dashed line) with the solution, and the chamber 28 has a helical liquid guide from the measurement solution inlet 28 IN toward the contact site S. A chamber is provided with a plate 29 and the liquid after measurement is discharged from a liquid discharge port 28OUT.
By using the detector chamber 28 having such a configuration, when the oxidizing agent is injected into the measurement solution in front of the chamber, it is efficiently mixed in the measurement solution by the helical liquid guide plate 29 of the liquid guide plate. The pH can be easily lowered to around 2, and it has the effect of efficiently obtaining free carbon dioxide gas.
In addition, the helical liquid guide plate makes the water flow turbulent and the mixing effect of the oxidant causes the water flow to become turbulent, and the detection surface of the DCO ₂ detector (sensor) is constantly exposed to fresh water, resulting in an efficient detection effect. There are advantages that can be obtained.

In addition, as shown in FIG. 2-3(d), the detection of the amount of CO ₂ in the measurement solution or the oxidized measurement solution is performed from the measurement solution or oxidized measurement solution side through the reflector/CO ₂ permeable membrane. / A composite film composed of the order of the protective member or the order of the CO ₂ permeable film / reflector _is obtained. (indicated by arrow lines), the sensitivity is increased by increasing the absorbance of the CO ₂ gas in the mid-infrared rays, and the detector performs quantitative analysis using the absorbance of the CO ₂ gas in the mid-infrared rays. Reference numeral 260 is a reflector.
Furthermore, as shown in FIGS. 2-4(e) and 2-4(f), the detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement solution enables continuous measurement and passes through a permeable membrane. In order to avoid the effect of the _CO2 gas that has passed through the permeable membrane and exited to the outside of the permeable membrane, the _CO2 gas that has passed through the permeable membrane and exited to the outside of the permeable membrane is used as the sweep gas SG, such as nitrogen gas or _CO2 free gas. is used, and the CO ₂ gas emitted outside is discharged to the outside of the device and not used for measurement, and the CO ₂ gas contained in the permeable membrane is quantitatively analyzed using the absorbance of mid-infrared rays. performed by the instrument. This technique is available in the detectors used in the present invention.

Next, a method for measuring the total organic carbon content in an aqueous solution using the total organic carbon measuring device according to this embodiment will be described with reference to FIGS. 1-1 and 1-2. The DCO ₂ detectors 1a and 1b described in (a) of FIG. 2-1 are used as the detectors in the figure.
As shown in FIGS. 1-1 and 1-2, each component is connected by piping to prepare total organic carbon measuring devices 10A and 10B. The common configuration of the total organic carbon measuring apparatuses 10A and 10B is that the measurement solution Ls is circulated from the liquid storage tank 4 to the pipe 6 using the pump P1, and the detector IN (1a) is included in the measurement solution Ls along the way. Inorganic carbon (IC) is detected and its "inorganic carbon concentration: IC" is measured.

Next, the measurement solution Ls is sent to the oxidation chamber 2, where it is irradiated with ultraviolet rays from an ultraviolet source (here, an ultraviolet lamp “UV lamp” UVp), and oxidized so that the solution contains Carbonization of the organic matter (that is, generation of organic carbon) is performed, and the liquid containing the organic carbon (also referred to as "oxidized measurement solution") flows through the pipe 6 and is sent to the detector OUT (1b) for detection. By measuring the CO ₂ (carbon dioxide gas) concentration contained in the liquid with the device OUT (1b), it is possible to calculate the "total carbon concentration: TC" contained in the measurement solution Ls. In addition, a high-temperature oxidation chamber that can oxidize the contained organic matter while the solution remains liquid under high temperature and high pressure conditions that do not vaporize the solution, such as 230° C. and 30 kg/cm ² , should be used. In the normal high-temperature oxidation method, the solution vaporizes, but it is possible to oxidize the organic substance in a liquid state under high temperature and high pressure conditions that do not vaporize. It is also possible to adopt a combustion method instead of a method, and the present CO ₂ sensor can be used.
That is, replacing the UV oxidation chamber with a high temperature oxidation chamber can provide the same effect or better.

Here, as described above, in the total organic carbon measuring apparatus according to the present invention, in the process of oxidizing organic matter to CO ₂ , when high-concentration organic matter is oxidized, part of the "dissolved carbon dioxide gas" is gasified and " It may cause gas-liquid two-phase flow.
In such a state, in the total organic carbon measuring apparatus according to the present invention using a dissolved carbon dioxide gas detector, bubbling CO ₂ causes measurement errors. As in the total organic carbon measuring apparatus 10B, it is preferable to use a method of dissolving the CO ₂ component that is gasified and formed into bubbles using a "gas-liquid two-phase flow mixer (code 8)".

From the "inorganic carbon concentration: IC" contained in the measurement solution obtained by measurement and the "total carbon concentration: TC" contained in the oxidized measurement solution, the following formula (1) is used to calculate the "total Organic carbon concentration: TOC” is calculated.

In the measurement of total organic carbon according to the present invention, it should be noted that the dissolved _CO2 in the aqueous solution to be _measured changes its _form depending on the pH. Gas measurements become pH dependent.
For this purpose, an acid such as phosphoric acid or sulfuric acid is added as an oxidizing agent to the aqueous solution to be measured to lower the pH to about 2. In this state, everything becomes "free carbon dioxide gas", so it is necessary to remove "inorganic carbon IC". In this case, when aeration is performed with nitrogen gas, all of the gas can be separated as CO ₂ gas, so that the detector measurement according to the present invention becomes possible.
In addition, if the pH is a constant value, it is also possible to measure without pH control from a calculation point of view by setting a calibration curve.

1a, 1b DCO ₂ detector (1a: detector IN, 1b: detector OUT)
2, 41, 51, 61 Oxidation Chamber 4 Measurement Solution (Measurement Water) Storage Tank 5 Drain Port 6 Piping 7 pH Adjuster (Oxidant Supply Source)
7a Oxidant injection position 8 Gas-liquid two-phase flow mixer 10A, 10B Total organic carbon measuring device 30, 40, 50, 60 (conventional) total organic carbon measuring device 21 CO ₂ permeable membrane 22 Light emission Device 23 Light receiver 25 Protective member (sapphire glass plate)
26 reflector (gold-plated punching plate)
26a _CO2 entry/exit hole 27 adsorption thick film 28 detector chamber 28IN measurement solution inlet 28OUT liquid outlet 29 helical liquid guide plate 31 high temperature combustion furnace 32, 42 NDIR (infrared spectroscopy)
33, 43 Gas-liquid separator 34, 44 Dehumidifier 35, 45 Halogen scrubber 36, 46 Aerator (IC remover by _N2 gas purge)
37 Measurement solution injector 58a, 58b Conductivity meter 62 Ultrapure water device 63 Ion exchange resin 68a, 68b Thin film 260 Reflector H Heater Ls Measurement solution (measurement water)
Ls ^A oxidized measuring solution Ls ^B measuring solution Ox oxidizing agent P1, P2 pump UVp UV lamp (ultraviolet source)
S Contact part SG Sweep gas

Claims (10)

an oxidation chamber for forming an oxidized measurement solution by irradiating the measurement solution with ultraviolet rays from an ultraviolet source or burning organic matter contained in the measurement solution under high temperature and pressure conditions; and a side for supplying the measurement solution to the oxidation chamber. , and a DCO ₂ detector for measuring dissolved carbon dioxide gas (dissolved CO ₂ ) provided on either or both of the sides discharging the oxidized measurement solution from the oxidation chamber. . 2. A pH adjustment unit for introducing an oxidizing agent for adjusting the pH of the measurement solution into the measurement solution upstream of the DCO ₂ detector on the side of supplying the measurement solution to the oxidation chamber. Total organic carbon measuring device according to. 2. A total organic carbon measuring apparatus according to claim 1, wherein said UV source is an ultraviolet lamp (UV lamp) or an excimer lamp. 2. The method according to claim 1, wherein the measuring solution whose _CO2 amount is detected by the _DCO2 detector on the side supplying the measuring solution to the oxidation chamber is adjusted so that the pH is 2. Organic carbon measuring device. Detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement _{solution is achieved by taking CO 2 absorbed} by the measurement solution or formed in the oxidized measurement solution directly into the permeable membrane. is detected by mid-infrared rays, but in order to enable continuous measurement, the CO ₂ in the permeable membrane is separated from the solution by obtaining a permeable membrane that can freely enter and exit, and after obtaining the CO ₂ gas, the CO ₂ gas 2. The total organic carbon measuring apparatus according to claim 1, characterized in that the detector performs quantitative analysis using the absorbance of mid-infrared rays. Detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement solution _is achieved by taking CO ₂ absorbed by the measurement solution or formed in the oxidized measurement solution directly into the permeable membrane. is detected in the mid-infrared, but in order to enable continuous measurement and to avoid the influence of CO ₂ gas that has passed through the permeable membrane and exited the permeable membrane, The CO ₂ gas that has flowed outside is discharged to the outside of the device and is not used for measurement, and the detector quantitatively analyzes the CO ₂ gas contained in the permeable membrane using the absorbance of mid-infrared rays. The total organic carbon measuring device according to claim 1, characterized in that: Detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement solution causes CO ₂ contained in the measurement solution or CO ₂ formed in the oxidized measurement solution to be transferred to the measurement solution or the oxidized measurement solution. , a composite film composed of the order of reflector/CO ₂ permeable film/protective member or the order of CO ₂ permeable film/reflector is obtained, and the CO ₂ gas transmitted through the permeable film and discharged to the outside is not used for measurement, and the CO ₂ gas inside the permeable membrane reciprocates the mid-infrared ray multiple times inside the permeable membrane, increasing the absorbance of the CO ₂ gas to the mid-infrared ray to increase the sensitivity. 2. A total organic carbon measuring apparatus according to claim 1, wherein said detector quantitatively analyzes using absorbance of mid-infrared rays of _two gases. Detection of the amount of CO ₂ in the measurement solution or in the oxidized measurement _solution is achieved by separating CO ₂ contained in the measurement solution or formed in the oxidized measurement solution by obtaining a permeable membrane to separate CO _2. The total organic carbon measuring device according to claim 1, characterized in that it is carried out by said detector to obtain 2 gases, and the obtained CO ₂ gas is quantitatively analyzed with mid-infrared rays. The DCO ₂ detector has a housing having a liquid inlet on one end and a liquid outlet and a detector installation portion on the other end, and the flow provided inside the housing. 2. The detector according to claim 1, wherein the detector is installed at the position where the detector is installed in a detector chamber comprising a helical liquid guide plate extending from an inlet to a contact position between the detector and the liquid. Total organic carbon measuring device. The gas-liquid two-phase flow mixer is used to convert bubbles formed by vaporization of CO ₂ dissolved in the measurement solution or oxidized measurement solution into CO ₂ dissolved in the measurement solution or oxidized measurement solution. The total organic carbon measuring device according to claim 1, characterized in that

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