JPH10213578A - Water quality analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase measurement sensitivity to nitrogen in a water quality analyzer in which both TOC and TN in a water solution specimen can be measured by one analyzer. SOLUTION: An oxidation catalyst 4 in a reaction tube 6 is heated to a specified temperature of 680 to 900 deg.C by an electric furnace 8, and refining air is fed as carrier gas from a flow control part 12 to the reaction tube 6 at a flow rate of 150ml/min. Under the conditions, a water solution specimen of 100μl is sampled by a specimen sampling part 10, and filled into the reaction tube 6. Also the specimen gas vaporized in the reaction tube 6 is fed through a dehumidifying part 14 to the CO2 meter 16 of an NDIR (Non-dispersion type infrared spectrophotometer) by the carrier gas, and the CO2 density is measured. Then it is fed to a chemical luminous type NO meter 18, and NO density is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for analyzing TOC (total organic carbon) and TN (total nitrogen) in an aqueous solution sample using a single analyzer.
And a water quality analyzer that can measure both. Such a water quality analyzer vaporizes an aqueous solution sample by catalytic pyrolysis, and converts all nitrogen in the sample to NO and all carbon to C
An oxidation reaction section for converting to O ₂ , a sample sampling section for collecting a certain amount of an aqueous solution sample and injecting it into the oxidation reaction section, a carrier gas supply section for supplying a carrier gas to the oxidation reaction section, and a carrier gas from the oxidation reaction section A NO detection unit for detecting NO in the sample vaporized gas sent together with the gas and a CO ₂ detection unit for detecting CO ₂ in the sample vaporized gas are provided. Such a water quality analyzer is used as a TOC monitor or a TN monitor for monitoring pollutants contained in sewage and river water, and is used in sea areas where environmental standards are established or in factories where wastewater standards are established. It is used for monitoring water quality.

[0002]

2. Description of the Related Art A non-dispersive infrared CO ₂ meter using a non-dispersive infrared spectrophotometer (NDIR) is used as a detection unit in a TOC meter for measuring only TOC. A TN meter that measures only TN includes a chemiluminescence NO meter that includes an ozone generation unit as a detection unit and measures light emission due to the reaction between NO and ozone supplied from the ozone generation unit, or CO ₂
A non-dispersive infrared NO meter using NDIR is used in the same manner as the meter.

[0003] However, in a water quality analyzer in which both TOC and TN can be measured by one analyzer, both the CO ₂ meter and the NO meter use NDIR as a detection unit. This is because even if the NDIR is the same device, the type of gas sealed in the filter cell is different,
This is because it has versatility that different component gases can be measured, and the apparatus is simple.

[0004]

Problems to be Solved by the Invention NDIR as NO meter
Was found to be insufficient in measurement sensitivity to nitrogen. Accordingly, an object of the present invention is to improve the measurement sensitivity to nitrogen in a water quality analyzer capable of measuring both TOC and TN in an aqueous solution sample with one analyzer.

[0005]

According to the present invention, a chemiluminescence type (chemiluminescence type) is provided which includes an ozone generator as an NO detector and measures light emission due to the reaction between ozone and NO supplied from the ozone generator. A NO meter is used as the CO ₂ detection unit, and a non-dispersive infrared CO ₂ meter is used as in the related art. Regarding NO detection, a chemiluminescent NO meter can measure with higher sensitivity than NDIR.

[0006]

FIG. 1 schematically shows an embodiment. Reference numeral 2 denotes an oxidation reaction section, and a quartz glass reaction tube 6 filled with an oxidation catalyst 4 of a metal oxide or a noble metal catalyst is heated to a predetermined temperature by an electric furnace 8. A certain amount of the aqueous solution sample is collected by the sample sampling unit 10 and injected into the reaction tube 6 from above. The aqueous solution sample injected into the reaction tube 6 comes into contact with the heated oxidation catalyst 4 to be thermally decomposed and vaporized, and the nitrogen component in the sample becomes NO.
And at the same time the carbon component is converted to CO ₂ . From the upper part of the reaction tube 6, purified air from which the carbon content has been removed is controlled as a constant flow rate by the flow rate control unit 12 and supplied as a carrier gas.

[0007] The sample gas vaporized in the reaction tube 6 is sent by a carrier gas, guided to a non-dispersive infrared CO ₂ meter 16 as a CO ₂ detector through a dehumidifying section, and the CO ₂ concentration is measured. The sample gas that has passed through the CO ₂ meter 16 is led to a chemiluminescence type NO meter 18, where chemiluminescence generated by the reaction of NO in the sample gas with ozone supplied from the ozone generator 20 is detected. The NO concentration is measured.
The sample gas that has passed through the NO meter 18 is released through an ozone decomposition unit. The ozone generator 20 uses air as a raw material. As the raw material, purified air from which carbon has been removed is supplied at a constant flow rate controlled by the flow rate control unit 12.

The detection outputs of the non-dispersive infrared CO ₂ meter 16 and the chemiluminescence NO meter 18 are respectively processed by a data processing section 22 to obtain the concentrations of CO ₂ and NO, respectively. 24. The data processing unit 22 is an analog amplifier for amplifying the detection output of the non-dispersive infrared CO ₂ meter 16 and the chemiluminescence NO meter 18, an A / D converter for converting the amplified output to a digital signal, and the converted signal. CO ₂ and NO from the digital signal
And the like for calculating the density of the image.

Next, the operation of this embodiment will be described. The oxidation catalyst 4 in the reaction tube 6 is heated to 680 to 900 ° C. by the electric furnace 8.
, And purified air is supplied as a carrier gas from the flow controller 12 to the reaction tube 6 at a flow rate of 150 ml / min. In this state, a 100 μl aqueous solution sample was collected by the sample
Inject into The sample gas vaporized in the reaction tube 6 is sent by a carrier gas, passed through the dehumidifying section 14 to the CO ₂ meter 16 to measure the CO ₂ concentration, and then to the NO meter 18 to measure the NO concentration.

In the embodiment shown in FIG. 1, the CO ₂ total 16 and the NO total 1
Since 8 is connected in series, the sample gas vaporized in the reaction tube 6 is led to the NO meter 18 via the CO ₂ meter 16, and the same sample gas is measured by both the CO ₂ meter 16 and the NO meter 18. .

FIG. 2 shows an example of another arrangement of the CO ₂ meter 16 and the NO meter 18. In FIG. 2, the sample gas vaporized in the reaction tube 6 is sent by the carrier gas, and
After that, the switching unit 26 switches between the CO ₂ meter 16 and the NO meter 18 and guides them.

[0012]

According to the present invention, in a water quality analyzer capable of measuring both TOC and TN in an aqueous solution sample with a single analyzer, a chemiluminescent NO meter is used as the NO detecting portion, so that CO _{2 can be} detected. And NO detector are both NDI
Compared with the conventional analyzer using R, the sensitivity of measuring the amount of nitrogen is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing one embodiment.

FIG. 2 is a block diagram showing another arrangement example of the CO ₂ meter and the NO meter.

[Explanation of symbols]

2 Oxidation reaction unit 4 Oxidation catalyst 6 Reaction tube 8 Electric furnace 10 Sample sampling unit 12 Flow control unit 16 Non-dispersive infrared CO ₂ meter 18 Chemiluminescence NO meter 20 Ozone generation unit 22 Data processing unit

Claims (1)

[Claims] An oxidation reaction section for thermally decomposing and vaporizing an aqueous solution sample, converting all the nitrogen in the sample to NO and converting all carbon to CO ₂ , and collecting a certain amount of the aqueous solution sample to obtain the oxidation reaction section A sample sampling unit for injecting the carrier gas to the oxidation reaction unit, a carrier gas supply unit for supplying a carrier gas to the oxidation reaction unit, a NO detection unit for detecting NO in the sample vaporized gas sent together with the carrier gas from the oxidation reaction unit, and a sample thereof. In a water quality analyzer provided with a CO ₂ detecting unit for detecting CO ₂ in a vaporized gas, the NO detecting unit includes an ozone generating unit and measures light emission due to a reaction between ozone supplied from the ozone generating unit and NO. A water quality analyzer, wherein the CO ₂ detection unit is a non-dispersive infrared CO ₂ meter.