JP2953904B2 - Analyzer for silica component in water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring and analyzing silica components in water, and more particularly to an analyzer capable of continuously or intermittently measuring the total silica content including not only ionic components but also non-ionic components. It concerns the device.

[0002]

2. Description of the Related Art In order to control the operation of a pure water producing apparatus, a reverse osmosis membrane apparatus, a condensate desalination apparatus, etc., various conventional silica component measurement / analysis apparatuses for measuring silica components in water have been used. For example, in a pure water production system, the silica concentration in the treated water is measured, and when the concentration in the treated water exceeds a predetermined set value, the silica is used so as to perform an appropriate corresponding operation necessary for the operation of the equipment. Have been.

[0003] The measurement and analysis of the silica component in water in these apparatuses is based on a method based on JIS K0101. In short, the heteropoly compound formed by the reaction of ionic silica with ammonium molybdate (molybdate reagent). The silica is quantified by measuring the yellow absorbance of the sample. There is also known a method in which the produced heteropoly compound is reduced with 4-amino-3-hydroxy-1-naphthalenesulfonic acid to convert it to molybdenum blue, and the absorbance is measured to quantify silica.

In recent years, there has been a demand for producing and managing cleaner high-purity water, which is generally called ultrapure water. This is because, for example, in the semiconductor manufacturing field, stains may remain on a wafer whose semiconductor has been washed with pure water, which is one of the causes of lowering the product yield. It has been pointed out that many of the causes of this stain are derived from silica components in water.

However, water quality cannot be controlled for all the silica components that cause such spots, depending on the measuring method using the molybdic acid reagent described above. This is because, as can be understood from the principle, only the ionic silica component can be measured by the above-mentioned measuring method, and the non-ionic silica component present in a trace amount in water (usually “colloidal silica”) cannot be quantified. is there.

On the other hand, as a method for quantifying the colloidal silica component in water, for example, a sample is filtered (pore size 0.45 to 0.45).
1 mm), add sodium carbonate to the filtrate and boil to convert nonionic silica into an ionized form, and then quantify it with molybdenum yellow and blue (JIS K010).
1).

As a method for quantifying the total silica component, a JIS K0101 gravimetric method is also known. This method involves adding hydrochloric acid and perchloric acid to a sample and heating the sample to generate white smoke of perchloric acid. And dehydrate the silica to make it insoluble,
After dissolving the salts by adding water, the silica is separated by filtration, the silica is volatilized with sulfuric acid and hydrofluoric acid, and the silica is quantified from the weight loss. It is also known to add sodium carbonate to a sample, evaporate it to dryness, melt it, convert the silica into ions, and quantify the sample with molybdenum yellow and blue.

However, these methods of measuring the colloidal silica component or the method of measuring the total silica component require both troublesome and time-consuming operations such as heating and boiling, and the measurement requires a pure water production apparatus or the like. It was not possible to incorporate a device for this. However, even if the treated water is taken out and the concentration of all silica components in the treated water is measured in the laboratory by the above method, and the measurement result indicates that the quality of the treated water is low, the corresponding operations required for the equipment are considerable. Can be performed only after a long time delay, and in fact, the control is performed only by measuring the ionic silica component using the above molybdic acid reagent, which can perform substantially in-line measurement. It is the current situation.

[0009]

SUMMARY OF THE INVENTION In view of the above-mentioned state of the art, the present inventor has proposed a colloidal silica component in treated water such as a pure water production device, a reverse osmosis membrane device, and a condensate desalination device. The present inventors have intensively studied a method capable of measuring all silica components quickly and with a simple method, and have accomplished the present invention.

That is, the present invention makes it possible to quickly and easily measure the total silica component (or separately the ionic and non-ionic silica components) in water of interest, including both ionic and non-ionic silica components. An object of the present invention is to provide a device for analyzing a silica component in water that can be obtained.

Another object of the present invention is to provide a simple silica component analyzer capable of in-line measuring all silica components in treated water of various facilities and the like.

Still another object of the present invention is to continuously monitor the total silica component in the treated water of various facilities, whereby the concentration of the silica component in the treated water is controlled to a predetermined control reference value. It is an object of the present invention to provide a silica component analyzing apparatus capable of promptly performing a corresponding operation of the equipment when exceeding the limit, and realizing good management of treated water quality.

[0013]

Means for Solving the Problems and Actions The present inventor has conducted various studies to achieve the above object, and has conducted conventional studies on the treatment of inorganic fine particles in ultrapure water. For example, forcing colloidal substances by bubbling ozone. Proposal to oxidize to oxidized solid particles and remove them ("A Mechanistic Study of Ozon
e-Induced Paarticle Destabilization ", JOURNAL AWWA,
1991), this method cannot ionize colloidal silica in water. No other suitable prior art is known for ionizing inorganic fine particles contained in pure water.

However, the inventor of the present invention has found that when treatment is carried out in combination with forced oxidation and ultraviolet irradiation, ionization of colloidal silica occurs, which has not been predicted at all. The present invention has been made based on such findings. That is, the characteristics of the apparatus for analyzing a silica component in water according to the present invention include a sampling pipe for diverting sample water from a main pipe through which water to be analyzed flows, and a non-water sample contained in the sample water flowing through the sampling pipe. An ionization apparatus for ionizing an ionic silica component, and a reagent for injecting a reagent used for measurement of molybdenum yellow absorption spectrophotometry or a reagent used for measurement of molybdenum blue absorption spectrophotometry into sample water passing through the ionization apparatus Injection means, optical means for detecting the yellow or blue absorbance of the sample water after reagent injection, the ionization treatment device, the oxidant injection means for bringing the oxidant into contact with the sample water, and irradiating ultraviolet rays The ultraviolet irradiation means.

In the ionization treatment apparatus having the above structure, the oxidizing agent injecting means and the ultraviolet irradiation means may be provided as one apparatus, but it is preferable in terms of structure that they are separately provided so as to form sequential steps. The oxidizing agent injecting means is, for example, an oxidizing gas such as an ozone gas or a chlorine gas, or an oxidizing liquid such as sodium hypochlorite is directly injected into a sample sampling pipe, or an oxidizing gas is injected into the tank while passing the sample water through the tank. It can be provided to inject an agent. As the ultraviolet irradiation device, an existing ultraviolet irradiation device can be used, but it is preferable to use a device of a type in which the sample water flows around the ultraviolet light emitting lamp.

As the reagent injecting means for injecting the reagent into the sample water having passed through the ionization apparatus, an appropriate device for injecting a required reagent can be used.
The apparatus shown in FIG. 1 or FIG. 2 of JP-A-51 can be used. Reagents, when performing molybdenum yellow absorption spectrophotometry, in addition to ammonium molybdate solution,
When sulfuric acid, hydrochloric acid, oxalic acid, or the like is used and molybdenum blue absorption spectroscopy is carried out, 4-amino- In addition to 3-hydroxy-1-naphthalenesulfonic acid, hydrochloric acid, oxalic acid and the like are used.

An optical device for measuring the absorbance of the sample water colored yellow or blue, for example, a device for passing visible light through a filter to a specific wavelength, or a light emitting diode for emitting light of a specific wavelength An optical device in which a light-emitting source composed of a light-emitting element such as a photocell and a light-receiving part composed of a light-receiving element such as a phototube or a phototransistor are opposed to each other with a transparent cell through which sample water passes can be exemplified. The quality of the water can be monitored by displaying the amount of light with a galvanometer or by performing appropriate arithmetic processing using a computer and displaying it on a CRT or the like. By transmitting the necessary control information to the control device of the treated water treatment equipment, it is possible to realize preferable management of the treated water quality.

The sample collection tube can switch between a path for flowing the sample through the ionization apparatus to the reagent injecting means and a path for bypassing the ionization apparatus and flowing the sample to the reagent injecting means. If provided, it is possible to arbitrarily select between measuring and analyzing only the silica component of the ionic substance contained in the sample water in a state without ionization treatment and measuring and analyzing the total silica content. It is also possible to accurately grasp both the and the nonionic silica component.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. Example 1 In FIG. 1, reference numeral 1 denotes a main pipe through which treated water of, for example, a pure water production apparatus flows, and sample water diverted through a sampling pipe 2 branched from the main pipe 1 continuously. It is sent to the lower part of the ozone diffusion tank 3. Ozone is injected into the ozone diffusion tank 3 from below by an ozone gas injection pipe 4, and exhausted ozone gas is exhausted through an exhaust pipe 5.

The sample water that has been ozone diffused in the ozone diffusion tank 3 is sent from the upper part of the ozone diffusion tank 3 to the lower part of the next storage tank 6, and after the deaeration of ozone in water is performed. It is sent to the ultraviolet irradiation device 7 from above.

The ultraviolet irradiation device 7 is provided so that a sample water flows along a lengthwise direction of a transparent glass tube 8 having a built-in ultraviolet light-emitting lamp. Irradiated.

The sample water which has been irradiated with the ultraviolet rays is sent to the detection device 10 through the storage tank 9, and the measurement is performed by the molybdenum yellow absorption photometry or the molybdenum blue absorption photometry.

FIG. 2 shows an example of an apparatus configuration capable of performing both the measurement by the molybdenum yellow absorption spectrophotometer and the measurement by the molybdenum blue absorption spectrophotometer of the detection apparatus 10. This is a known apparatus. The configuration will be briefly described along with the operation.

First, the sampling valve 101 is opened, a predetermined amount of sample water is first taken into a reaction tank 102 made of a transparent material, and the sampling valve 101 is closed. Next, while stirring, a mixed solution of hydrochloric acid and ammonium molybdate as a reagent is supplied from the first reagent storage tank 103 to the reaction tank 1 by a pump 104.
02 and allowed to react for a certain period of time. Then
The oxalic acid solution is injected into the reaction tank 102 from the second reagent storage tank 105 by the pump 106, and the reaction is similarly performed for a predetermined time. Thereafter, a certain amount of a mixture of sodium sulfite, sodium hydrogen sulfite, and 4-amino-3-hydroxy-1-naphthalenesulfonic acid is injected from the third reagent tank 107 into the reaction tank 102 by the pump 108, and the mixture is supplied for a certain time. Allow the reaction to take place.

By the above operation, the sample water taken into the reaction tank reacts with the ionic silica contained therein to give a blue color, and the blue color is contained. It is proportional to the amount of the ionic silica component. The light from the light emitting source 109 is transmitted through the reaction tank 102 to the light receiving unit 11.
At 0, the light is received, photoelectrically converted, and measured by the galvanometer 111. The amount of total silica contained in the sample water can be determined by comparing this measurement result with a previously determined calibration curve.

After the measurement, the sample water in the reaction tank 102 is drained by the drain valve 112 to prepare for the next sample water measurement.

Using the above-described apparatus shown in FIGS. 1 and 2, an analysis test by the following molybdenum yellow absorption spectrophotometry was performed. For comparison, all silica was analyzed according to the procedure specified by the molybdenum yellow absorption spectrophotometer of JIS K0101, and the results are shown in Table 1 below.

As sample water, working waters A and B and city waters A and B were passed through an ozone diffusion tank 3 having a capacity of 100 ml at a flow rate of 10 ml / min, and ozone was injected into an ionization apparatus. Using an ozone master (ozone generator manufactured by Sakura Co., Ltd.), air was diffused to a dissolved ozone concentration of 5 ppm.
A lamp having a 15 W ultraviolet lamp inside was used.

[0029]

[Table 1]

As can be seen from the results, the results measured using the apparatus of the present invention were substantially the same as the results analyzed by the JIS method, and it was confirmed that the analysis of all silica was possible with the apparatus of the present invention. Was done.

Embodiment 2 The apparatus shown in FIG. 3 is different from the apparatus shown in FIG. 1 in that a sampling pipe 2 branched and connected to a main pipe 1 is provided with an ozone diffusion tank 3, an ultraviolet irradiation device 8, and a storage tank 6, 9 is provided so as to have a path for flowing the sample water to the detection device 10 through the ionization processing device 9 (hereinafter referred to as a main path) and a path for flowing the sample water to the detection device 10 through the bypass path 11. ing. Reference numerals 12 and 13 denote switching valves for switching between opening and closing so that the sample water flows from one of the paths. Other configurations are the same as those in FIG.

The apparatus shown in FIG. 3 is connected to the apparatus shown in FIG.
Tests were performed using, as sample water, ion-exchanged water of the ultrapure water production apparatus, permeated water of the reverse osmosis membrane apparatus, and concentrated water on the non-permeate side of the reverse osmosis membrane apparatus. The test is performed by switching the switching valves 12 and 13 so that each sample water passes through the ionization apparatus (via the main path) and does not pass (via the bypass path). The processing conditions and the like were the same as in Example 1.

For comparison, all of the sample waters were analyzed for total silica according to the procedure specified in the above-mentioned molybdenum yellow absorption spectrophotometer of JIS K0101. The results are shown in Table 2 below.

[0034]

[Table 2]

From the above results, when the ionization treatment was performed via the main path, the measurement of all silica substantially in accordance with the JIS method can be performed similarly to the first embodiment, and the measurement was performed via the bypass path. When the ionization treatment is not performed, it can be seen that the measurement of only the ionic silica component except the colloidal silica component in the sample water can be performed in the same manner as in the related art, and as a result, the ionic and nonionic silica components can be measured. The content could be analyzed.

The present invention is not limited to the above-described embodiment. For example, it is also possible to continuously measure and analyze the treated water of a pure water production facility.

FIG. 4 shows an example of an apparatus which can be used as the detection apparatus 10 of the apparatus shown in FIG. 1 or 3 for this purpose. In this detection device, the sample water is continuously flowed from the sampling valve 101 to the coil-shaped reaction pipe 120, the transparent cell 122 in the dark box 121, and the water discharge pipe 123, and the first reagent storage tank 103 and the second reagent storage 105 are provided on the way. And a reaction of molybdenum yellow absorption spectroscopy is performed in the reaction pipe 120, and the absorbance is optically measured in the transparent cell 122, thereby realizing a continuous measurement analysis. it can.

[0038]

According to the apparatus for analyzing a silica component in water according to the present invention, the total silica component including both ionic and nonionic components in the target water (or separately the ionic and nonionic silica components) Can be measured quickly and easily.

In addition, there is an effect that all the silica components in the water in the various facilities can be easily measured and analyzed in-line, and since continuous monitoring can be performed, the concentration of the silica component in the treated water is a predetermined control standard. When the value exceeds the value, there is an effect that the corresponding operation of the equipment can be promptly performed, and good management of the treated water quality can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a configuration outline of an apparatus for analyzing a silica component in water according to the present invention,

FIG. 2 is a diagram showing an example of a configuration outline of a detection device used in the present invention,

FIG. 3 is a block diagram showing another example of a configuration outline of an apparatus for analyzing a silica component in water according to the present invention,

FIG. 4 is a diagram showing another example of the configuration outline of the detection device used in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main piping, 2 ... Sample collection pipe, 3 ... Ozone diffusion tank, 4 ... Ozone gas injection pipe, 5 ... Exhaust pipe,
6, 9 ... storage tank, 7 ... ultraviolet irradiation device, 8 ...
Transparent glass tube, 10 detection device, 11 bypass path, 12, 13 switching valve, 101 sampling valve,
102: reaction tank, 103: first reagent storage tank, 10
5 ... second reagent storage tank, 107 ... third reagent storage tank, 1
09: light emitting source, 110: light receiving unit, 20: galvanometer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 21/77 G01N 21/78 G01N 31/00 G01N 33/18

Claims (3)

(57) [Claims] 1. A sampling pipe for dividing a sample water from a main pipe through which water to be analyzed flows, and an ionization treatment for ionizing a non-ionic silica component contained in the sample water flowing through the sampling pipe. An apparatus, a reagent injecting means for injecting a reagent used for the measurement of molybdenum yellow absorption spectrophotometry or a reagent used for the measurement of molybdenum blue absorption spectrophotometry into the sample water passed through the ionization treatment apparatus, and a sample water after the reagent injection. Optical means for detecting the yellow or blue absorbance of the sample, wherein the ionization apparatus has an oxidizing agent injection means for injecting an oxidizing agent into the sample water, and an ultraviolet irradiation means for irradiating the sample water with ultraviolet light An analyzer for analyzing a silica component in water. 2. The analyzer according to claim 1, wherein the oxidizing agent is ozone. 3. The sample collection tube according to claim 1, wherein the sample collection tube has a path for allowing the sample to flow through the ionization apparatus to the reagent injecting means, and allows the sample to flow to the reagent injection means by bypassing the ionization apparatus. An analyzer for analyzing a silica component in water, wherein a path is provided so as to be switchable.