JP3484207B2 - Organic pollutant measurement method using ultraviolet oxidation - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring organic pollutants using ultraviolet oxidation, and more specifically, irradiating a sample water containing various organic compounds constituting organic pollutants with an ultraviolet lamp (UV lamp). The present invention relates to a novel method for measuring organic pollutants, which monitors organic pollutants.

[0002]

2. Description of the Related Art In recent years, the water source of water supply facilities often depends on river water.
Due to the concentration of the population, pollution of domestic wastewater has progressed, and the management of organic pollutants has become indispensable for supplying delicious water. The constituent components of this organic pollutant can be managed by measuring the COD component, but the COD analyzer has a problem in that it takes a long measuring time and is easy to maintain.

Further, conventionally, the water quality of public waters such as rivers, lakes and marshes of works and factories, and the degree of organic pollution are measured by measuring the absorbance of ultraviolet rays. The ultraviolet absorbance measuring method using this automatic ultraviolet absorbance measuring device (UV meter) does not require a reagent, and the measuring operation is simpler and easier than the COD analysis method described above, and maintenance is also extremely easy. , The COD analysis method is used instead of the COD analysis method, but the amount of the organic pollutants in the sample water is not always COD depending on the quality of the sample water.
It cannot be said that it has a good correlation with the value.

The present invention has been made in view of the above problems, and an object thereof is to further improve the correlation between the amount of organic pollutants in the sample water and the COD value without depending on the water quality of the sample water. Another object of the present invention is to provide a method for measuring an organic pollutant using ultraviolet oxidation.

[0005]

Means and Actions for Solving the Problems In the conventional ultraviolet absorptiometry, the inventors of the present invention have found that the amount of organic pollutants in the sample water is not always COD depending on the quality of the sample water.
Since a good correlation with the value cannot be obtained, as a means for obtaining an oxidation reaction close to the effect of the oxidizing power of KMnO ₄ used as a reagent when measuring COD components, an ultraviolet lamp (hereinafter,
Focusing on the irradiation effect of irradiating the sample water with a UV lamp). Then, by irradiating the sample water containing various organic compounds constituting the organic pollutant with a UV lamp,
Based on the principle that the organic pollutants are oxidized and decomposed by absorbing ultraviolet rays, the oxidation rates of various organic compounds constituting the organic pollutants with a UV lamp were measured in advance without a reagent. As a result, a good oxidation rate of various organic compounds, therefore, the this effect only by oxidizing power UV lamps to the organic pollutant water sample is effective closer to that of KMnO ₄ may be unsubstituted or reagents The present inventors have found out.

Actually, the measurement result of the oxidation rate (each concentration was set to about 50 ppmc) is shown in Table 1 below. From Table 1, other organic compounds except toluene are
It can be seen that the oxidation rate is close to the effect of the oxidizing power of KMnO ₄ . Note that toluene has a low solubility in sample water, and the measured values listed in Table 1 are not necessarily accurate as compared with other organic compounds.

[0007]

[Table 1]

Therefore, it is possible to obtain a measurement value of the amount of organic pollutants closer to the COD value by measuring the change amount of the UV absorbance before and after the irradiation of the UV lamp, as compared with the conventional UV absorbance measuring method. Good correlation with the COD value is obtained. That is, in the present invention, the correlation between the amount of organic pollutants and the COD value can be raised to one rank by taking out the oxidized portion of the organic pollutants in the sample water using the UV lamp.

Thus, the method for measuring organic pollutants using ultraviolet oxidation according to the present invention irradiates the sample water with ultraviolet rays to oxidize the organic pollutants in the sample water, and to measure the amount of change in the ultraviolet absorbance before and after the oxidation reaction. Measure .

That is, according to the present invention, by irradiating the sample water containing various organic compounds constituting the organic pollutant with a UV lamp, the organic pollutant is oxidized and decomposed by absorbing ultraviolet rays. Based on the principle that the oxidation of organic pollutants using a UV lamp
Since it shows an oxidation rate close to the effect of the oxidizing power of O ₄ , UV
The organic pollutants are measured by irradiating the lamp for a certain period of time or continuously to oxidize the organic pollutants in the sample water and measuring the amount of change in the UV absorbance before and after UV lamp irradiation in the UV wavelength range of 254 nm. By irradiating the sample water with a UV lamp, the amount of the organic pollutant measured only by extracting the oxidized component of the organic pollutant has a good correlation with the COD value. have.

At this time, unlike the COD analysis method of measuring organic pollutants using a KMnO ₄ reagent, the sample water is directly measured by the absorbance measurement method as in the present invention.
No reagent is required, and the measurement operation is simple and easy.

Further, unlike the conventional method for measuring the ultraviolet absorbance by a UV meter, in the present invention, the amount of the organic contaminants before and after the oxidation reaction of the organic contaminants by the irradiation of the UV lamp is measured by the ultraviolet absorbance, so that The effect of turbidity can be corrected.

Moreover, the organic pollutants in the sample water generally have an ultraviolet wavelength of 25 which is an index of the organic pollutants.
Since it strongly absorbs ultraviolet rays around 4 nm, the amount of organic pollutants is measured by measuring the amount of change in ultraviolet absorbance at a wavelength of 254 nm before and after the oxidation reaction of organic pollutants. 254
It is preferable to use a mercury lamp which has a radiation spectrum in the vicinity of nm and has a particularly strong light amount in the vicinity of a wavelength of 185 nm that promotes the oxidation of organic substances, because the oxidation is promoted and the measurement can be performed in a short time.

[0014]

Embodiments of the present invention will be described below.
However, the present invention is not limited thereby. 1 and 2 are views for explaining a first embodiment of the present invention. In FIG. 1 and FIG. 2, the method for measuring organic pollutants using ultraviolet oxidation uses an ultraviolet lamp 1,
Sample water 2 having various turbidity (pollution) B'and containing various organic compounds constituting the organic pollutant U ', and inorganic ions C'
For a certain period of time (t) to oxidize the organic pollutants in the sample water, and the ultraviolet absorbance Ab _{sT = 0} and the ultraviolet absorbance Ab before and after the oxidation reaction in the ultraviolet region wavelength near 254 nm.
_The amount of change ΔAb _s (= Ab _{sT = 0} −Ab _{sT = t} ) with _{sT = t} is measured, and the three-way solenoid valve 3, constant pressure trap 4,
Lighting of the ultraviolet lamp 1 using an organic pollutant measuring device including a sampling device composed of the measurement control device 5, an ultraviolet absorption meter 6 and an ultraviolet lamp 1 provided on the upstream side of the ultraviolet absorption meter. (Lighting pulse indicated by symbol P in FIG. 2) and measurement line switching by the three-way solenoid valve 3 (switching pulse indicated by symbol Q in FIG. 2) are synchronized, and the ultraviolet lamp 1 is not irradiated and before the oxidation reaction. UV absorbance Ab _{sT = 0} is the indicated hold value (= U + B +) before the oxidation reaction.
C), and after irradiating the sample water 2 with the ultraviolet lamp 1 for a certain time (t), the ultraviolet absorbance Ab _{sT = t} is obtained as the indicated hold value (= B ″ + C ″) after the oxidation reaction, The difference signal of the high and low of both instruction hold values is changed ΔAb _s [=
(U + B + C)-(B ″ + C ″)] can be used to measure the amount of organic pollutants. In FIG. 1, reference numeral 7 is a flow meter.

In FIGS. 3 and 4, while continuously flowing a small flow rate of sample water 2, oxidation is performed by turning on the ultraviolet lamp 1 provided in the preceding stage of the ultraviolet absorptiometer 6 (lighting pulse indicated by reference symbol R in FIG. 4). It is a figure for demonstrating the 2nd Example of this invention which was made to measure the amount of the produced organic pollutants with the ultraviolet absorptiometer 6.

In FIGS. 3 and 4, the method for measuring organic pollutants is as follows: a sampling device comprising a constant pressure trap 4 and a measurement control device 5, an ultraviolet absorptiometer 6, and an ultraviolet ray provided upstream of the ultraviolet absorptiometer. Using the organic pollutant measuring device composed of the lamp 1, the ultraviolet lamp 1 is intermittently turned on while continuously flowing a small amount of sample water 2, and the ultraviolet absorbance Ab _{sT = 0} , Ab _{sT The} amount of oxidized organic pollutants can be measured from the deviation of the maximum value and the minimum value of _{= t} .

In FIG. 5, a mercury lamp is used as the ultraviolet lamp 11, and the amount of the organic pollutant is measured by using an organic pollutant measuring device in which the reaction tank 11a by the ultraviolet lamp 11 and the detection cell 12 of the ultraviolet absorptiometer are integrated. It is a figure for demonstrating the 3rd Example of this invention made to measure.

In FIG. 5, the wavelength 254 is used in this embodiment.
A mercury lamp 11 having an emission spectrum in the vicinity of nm and a strong light amount in the vicinity of a wavelength of 185 nm that promotes oxidation of organic substances is used as an ultraviolet lamp, and the reaction tank 11a by the mercury lamp and the detection cell 12 are integrated. At the same time, the detection cell has a wavelength of 2 as an index of organic pollutants.
A 54 nm bandpass filter 13 is provided, and the two-way solenoid valve 1 is provided at the inlet 14 of the sample water 2 on the upstream side of the reaction tank 11a.
5, the two-way solenoid valve 15 is used to switch the inflow / outflow operation of the sample water 2 using the organic pollutant measuring device configured to provide the amount of the oxidized organic pollutant to the second amount.
It is measured by the same method as in the examples. Then, an optical system for measuring an absorbance of an arbitrary cell length L is configured to include a cell window 16, a slit 17, and a silicon photosensor 18 in addition to the bandpass filter 13. In FIG. 5, reference numeral 19 is an outlet for the sample water 2.

FIG. 6 shows a fourth embodiment of the present invention in which the amount of organic pollutants is measured while monitoring the ultraviolet absorbance Ab _{sT = 0} and the ultraviolet absorbance Ab _{sT = t} before and after irradiation with an ultraviolet lamp. In FIG. 6, the organic pollutant measuring apparatus is provided with a constant pressure trap 4, a two-way solenoid valve 20 and an ultraviolet lamp 1 sequentially from the inlet 14 side of the sample water 2,
An ultraviolet ray measuring tank 21 of an ultraviolet ray absorptiometer is provided in the middle of a branch channel G branched from the sample water introducing channel F formed between the two-way solenoid valve 20 and the ultraviolet lamp 1, and further on the downstream side of the ultraviolet lamp 1. A circulation pump 22 that circulates the sample water 2 from the ultraviolet ray measuring tank 21 to the ultraviolet ray lamp 1 side is provided between the ultraviolet ray measuring tank 21 and the ultraviolet ray measuring tank 21. In FIG. 6, reference numeral 23 is a rotary cell length modulation type ultraviolet absorptiometer.

The measurement sequence will be briefly described below. In FIG. 6, while opening the two-way solenoid valve 20,
After turning off the ultraviolet lamp 1, the sample water 2 was poured into the ultraviolet measuring tank 21 by the circulation pump 22 and the ultraviolet measuring tank 21 was filled with new sample water, and then the stable point of the indicated value of the ultraviolet absorptiometer was measured before the oxidation reaction. The ultraviolet absorbance value Ab _sT is read as ₀ , and then the two-way solenoid valve 20 is closed, the ultraviolet lamp 1 is turned on, and the sample water 2 is circulated by the circulation pump 22 while the organic pollutant in the sample water 2 is being circulated. And wait for the indicated value to stabilize, and after a certain period of time, read the UV absorbance value Ab _{sT = t} after the oxidation reaction, and obtain the Ab _{sT = 0.}
The amount of organic pollutants can be measured from the change value ΔAb _s between _{AbsT = t} and _{AbsT = t} .

[0021]

As described above, according to the present invention, the sample water containing various organic compounds constituting the organic pollutant is irradiated with a UV lamp, and the organic pollutant absorbs ultraviolet rays to be oxidized. Based on the principle that it is decomposed, the organic contaminants in the sample water are irradiated by irradiating the UV lamp, and the amount of change in the ultraviolet absorbance before and after the UV lamp irradiation is measured to measure the amount of the organic contaminants. By irradiating the sample water with a UV lamp,
The amount of the organic pollutant measured by only extracting the oxidized component of the organic pollutant can have a good correlation with the COD value.

At this time, unlike the COD analysis method for measuring organic pollutants using a KMnO ₄ reagent, the sample water is directly measured by the absorbance measurement method as in the present invention.
No reagent is required, and the measurement operation is simple and easy.

Also, unlike the conventional method of measuring the ultraviolet absorbance by a UV meter, in the present invention, the amount of the organic pollutants before and after the oxidation reaction of the organic pollutants by the irradiation of the UV lamp is measured by the ultraviolet absorbance, so that the sample water is used. The effect of turbidity can be corrected.

Moreover, the organic pollutants in the sample water generally have an ultraviolet wavelength of 25 which is an index of the organic pollutants.
Since it strongly absorbs ultraviolet rays around 4 nm, the amount of organic pollutants is measured by measuring the amount of change in ultraviolet absorbance at a wavelength of 254 nm before and after the oxidation reaction of organic pollutants. 254
The use of a mercury lamp having a radiation spectrum in the vicinity of nm and a particularly strong light amount in the vicinity of a wavelength of 185 nm that promotes the oxidation of organic substances has the advantage that the oxidation can be accelerated and measurement can be performed in a short time.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation in the first embodiment.

FIG. 3 is a structural explanatory view for explaining a second embodiment of the present invention.

FIG. 4 is a diagram for explaining an operation in the second embodiment.

FIG. 5 is a structural explanatory view for explaining a third embodiment of the present invention.

FIG. 6 is a structural explanatory view for explaining a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... UV lamp, 2 ... Sample water, 3 ... three-way solenoid valve, 4 ...
Constant pressure trap, 5 ... Measurement control device, 6 ... Ultraviolet light absorptiometer, 11 ... Ultraviolet lamp, ΔAb _s ... Absorbance change amount.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-228144 (JP, A) JP-A-62-228145 (JP, A) JP-A-62-228146 (JP, A) Actual development Sho-64- 34555 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 33/18 G01N 21/33 G01N 21/77

Claims (4)

(57) [Claims] 1. A method for measuring organic pollutants using ultraviolet oxidation, which comprises irradiating sample water with ultraviolet rays to oxidize the organic pollutants in the sample water and measuring the amount of change in ultraviolet absorbance before and after the oxidation reaction. A constant pressure trap, measurement system
Sampling device consisting of control device and UV absorption meter
And an ultraviolet ray run provided upstream of the ultraviolet ray absorptiometer.
Using an organic pollutant measuring device composed of
UV lamp continuously flowing a small amount of sample water
Lights up intermittently, and the maximum and minimum values of UV absorbance
From the deviation of the
Method for measuring organic pollutants used. 2. A mercury lamp having an emission spectrum near a wavelength of 254 nm and having a strong light amount near a wavelength of 185 nm that promotes the oxidation of organic substances is used as an ultraviolet lamp, and the reaction tank by the ultraviolet lamp and the ultraviolet absorptiometer are integrated. In addition, the ultraviolet absorption meter is provided with a bandpass filter having a wavelength of 254 nm, which is an index of organic pollutants, and a two-way solenoid valve is provided on the upstream side of the reaction tank to measure the organic pollutants. An organic pollutant using ultraviolet oxidation according to claim 1 , wherein an inflow / outflow operation of the sample water is switched by the two-way solenoid valve using an apparatus to measure the amount of the oxidized organic pollutant. Measuring method. 3. Irradiate the sample water with ultraviolet light
UV absorbance before and after the oxidation reaction by oxidizing mechanical pollutants
Of UV oxidation, which consists of measuring the change in
A method for measuring mechanical pollutants,
A pressure trap, a two-way solenoid valve and an ultraviolet lamp are installed in sequence.
The sample water guide formed between the two-way solenoid valve and the ultraviolet lamp.
An ultraviolet absorption meter was installed in the middle of the branch flow path branched from the inlet flow path.
Furthermore, at the downstream side of the UV lamp, the UV absorbance
Sample water between the UV absorptiometer and the
It was constructed by providing a circulation pump to circulate on the side of the lamp
Existence using UV oxidation using an organic pollutant measuring device
Method for measuring organic pollutants. 4. The two- way solenoid valve is opened, the ultraviolet lamp is turned off, sample water is poured into the ultraviolet absorptiometer to fill the ultraviolet absorptiometer with new sample water, and then the stable point of the indicated value of the ultraviolet absorptiometer is reached. Is read as the ultraviolet absorbance value before the oxidation reaction, after that, with the two-way solenoid valve closed, the ultraviolet lamp is turned on, the organic pollutants in the sample water are oxidized, waiting for the stability of the indicated value, The method for measuring organic pollutants using ultraviolet oxidation according to claim 3 , wherein the ultraviolet absorbance value after the oxidation reaction is read after a certain period of time, and the amount of the organic pollutants is measured from the change value of the ultraviolet absorbance before and after the oxidation reaction.