JP5631015B2 - Concentration measuring method and detecting method and device for specific oil in waste water or specific oil-containing waste water - Google Patents

Description

  The present invention relates to a technique for detecting a specific chemical substance or specific wastewater contained in wastewater such as factory wastewater or circulating water using fluorescence and / or ultraviolet / visible light absorption specific to a specific chemical substance or specific wastewater.

  Many chemical components (surfactant, cutting oil, etc.) are used in the industry, and some of these chemical components are mixed and treated in the factory drainage system. However, due to equipment troubles, etc., the mixing ratio into the drainage system will increase significantly, resulting in an increase in COD (chemical oxygen demand). doing. Therefore, it is necessary to quickly detect an increase in the concentration of chemical components in the drainage system.

  Methods for detecting the increase in the concentration of chemical components include test analysis methods such as COD, TOC (total organic carbon) and chromaticity described in Non-Patent Document 1 and Non-Patent Document 2, TOC automatic analyzer is on the market.

  In addition, there are measurement methods using a fluorescence photometry method and an ultraviolet / visible absorption photometry method which are optical measurement methods. These are methods in which the former applies a phenomenon of emitting specific fluorescence by applying excitation light to a specific chemical substance or specific waste water, and the latter is a method in which light absorption occurs at a specific excitation wavelength. Ultraviolet / visible absorptiometry has been applied to industrial wastewater, etc., and fluorometry has high detection sensitivity, and research has been conducted mainly on liquid samples with relatively low COD concentrations such as river water and lakes. (Non-Patent Document 3).

Industrial water test method JIS-K0101 Factory drainage test method JIS-K0102 Kazuhiro Komatsu, Akio Imai, Kazuo Matsushige, Kyoko Nara, Nobuyuki Kawasaki, Characterization of Lake and Basin Water DOM by Three-dimensional Excitation Fluorescence Spectroscopy, Journal of Water Environment Society, Vol. 31, no. 5,2007

Existing detection devices have the following problems.
First, since the COD automatic analyzer can continuously measure only every hour, it is difficult to detect an increase in concentration in real time, and there are problems of waste liquid disposal due to the use of chemicals and high running costs. Since the TOC automatic analyzer can perform continuous measurement only at intervals of 5 to 10 minutes, there is a time delay in detecting an increase in concentration.

  Next, the measurement method using the fluorometric method and ultraviolet / visible absorption photometric method, which are optical measurement methods, has high detection sensitivity in the fluorophotometric method, but the fluorescence is quenched (concentration quenching) in a high concentration range. In the ultraviolet / visible absorptiometric method, the absorbance exceeds the upper limit of detection, so that there is a problem that detection in a high concentration region and concentration estimation cannot be performed. Furthermore, these optical measurement methods are strongly influenced by suspended solids (SS). In other words, unlike river water and lakes, wastewater containing chemical components at high concentrations, such as factory wastewater, often contains SS at high concentrations, and light is blocked or absorbed by the contained SS, There is a possibility that fluorescence may be emitted from the SS itself, which has a problem of affecting the detection accuracy. In addition, there is a problem that fluorescence is quenched by the influence of pH, background, and coexisting salts (iron components, etc.) in the wastewater. Further, in the ultraviolet / visible absorptiometric method, there is a problem that SS adheres to the detection portion as dirt, making measurement difficult.

  From the above, it has been difficult to apply the fluorescence measurement method and the ultraviolet / visible absorption photometry method, which are optical measurement methods, to wastewater containing chemical components.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a method for measuring and detecting the concentration of a specific chemical substance or specific wastewater in wastewater that can be applied easily and quickly. .

  In order to solve the above-mentioned problems, the present inventors have diluted a wastewater containing a specific chemical substance or a specific wastewater at an appropriate dilution ratio calculated according to the raw water state, thereby obtaining a fluorometric method or an ultraviolet / visible light absorption. It came to provide the method and apparatus which measure and detect the density | concentration of a specific chemical substance or a specific waste water more effectively using a photometric method.

The gist of the present invention is the following (1) to ( 14 ).
(1) using a fluorescence specific to a particular oil or a particular oil-containing wastewater, in the method of performing density measurement of the particular oil or a particular oil-containing wastewater is mixed in the raw water,
The specific oil is a flame retardant hydraulic oil or a water-soluble cutting oil, and the specific oil-containing wastewater is a drainage containing a flame retardant hydraulic oil or a water-soluble cutting oil,
The fluorescence spectrum is measured for the specific oil or the liquid sample containing the specific oil-containing wastewater in the entire excitation wavelength range of 200 to 800 nm, and the excitation wavelength and the fluorescence wavelength at the peak position of the fluorescence spectrum intensity of the specific oil or the specific oil-containing wastewater. And create a calibration curve by obtaining the correlation between the fluorescence spectrum intensity at the peak position and the concentration of the soluble chemical oxygen demand in the specific oil or specific oil-containing wastewater. A correlation between the fluorescence spectrum intensity and the concentration of the soluble chemical oxygen demand in the database generation process is obtained for the liquid sample obtained by continuously sampling the database and the raw water. In addition, a dilution ratio setting step for calculating the dilution ratio of the liquid sample according to the raw aqueous state,
A dilution step of obtaining diluted raw water by mixing dilution water with a liquid sample obtained by continuously sampling the raw water at the dilution rate calculated in the dilution rate setting step;
In the diluted raw water, a measurement step of measuring the fluorescence spectrum intensity at the excitation wavelength of the peak position;
Using the correlation in the database creation step, from the measurement result in the measurement step, calculate the concentration of the soluble chemical oxygen demand of the specific oil or specific oil-containing wastewater in the diluted raw water, Furthermore, a concentration calculation step for calculating the concentration of the dissolved chemical oxygen demand of the specific oil or the specific oil- containing wastewater in the raw water using the dilution factor;
A method for measuring the concentration of a specific oil in a wastewater or a specific oil-containing wastewater.
(2) Preparation of the calibration curve uses an approximate expression represented by the following formula (1), and the concentration measurement of the specific oil or the specific oil-containing wastewater in the drainage according to (1) Method.
Fluorescence spectrum intensity = a {1-exp (−bC)} + d (1)
(Here, in the above formula (1), a, b and d are constants, and C is the soluble chemical oxygen demand of the oil or oil-containing waste water.)
(3) In the method for calculating the concentration of the soluble chemical oxygen demand of the particular oil or a particular oil-containing wastewater in the in the diluted raw water, previously soluble chemical oxygen demand concentration and total chemical oxygen demand by keeping the correlation relationship between the concentration of the amount, and calculates the concentration of total chemical oxygen demand from the concentration of the resulting soluble chemical oxygen demand is calculated, (1) Or the density | concentration measuring method of the specific oil or specific oil-containing waste water in the waste_water | drain as described in (2).
(4) One of the influence of solid matter in the fluorescence analysis and the influence of the background of the liquid sample is provided by providing an SS removal step in which a filter is installed as a solid matter removal treatment for the raw water or diluted raw water. Alternatively, the method for measuring the concentration of specific oil or specific oil-containing wastewater in wastewater according to any one of (1) to (3), wherein two effects are reduced.
(5) About said SS removal process, the blockage | closure of a filter is prevented by performing regular backwashing, The specific oil in any one of (1)-(4) characterized by the above-mentioned Or a method for measuring the concentration of specific oil-containing wastewater.
( 6 ) The appropriate dilution ratio calculated according to the raw water state uses an actual dilution ratio calculated based on flow rate data, (1) to ( 5 ), Of measuring the concentration of specific oil or specific oil-containing wastewater in the drainage of water.
( 7 ) Using the concentration measurement method according to any one of (1) to ( 6 ) above, a detection step that issues an alarm when a preset reference value is exceeded, And / or a coping process for coping with the concentration adjustment of the wastewater, and a method for detecting specific oil in the wastewater or specific oil-containing wastewater.
(8) using a fluorescence specific to a particular oil or a particular oil-containing wastewater, in the apparatus for performing the density measurement of the particular oil or a particular oil-containing wastewater is mixed in the raw water,
The specific oil is a flame retardant hydraulic oil or a water-soluble cutting oil, and the specific oil-containing wastewater is a drainage containing a flame retardant hydraulic oil or a water-soluble cutting oil,
The fluorescence spectrum is measured for the specific oil or the liquid sample containing the specific oil-containing wastewater in the entire excitation wavelength range of 200 to 800 nm, and the excitation wavelength and the fluorescence wavelength at the peak position of the fluorescence spectrum intensity of the specific oil or the specific oil-containing wastewater. And create a calibration curve by obtaining the correlation between the fluorescence spectrum intensity at the peak position and the concentration of the soluble chemical oxygen demand in the specific oil or specific oil-containing wastewater. Databaseization means,
For a liquid sample obtained by continuously sampling the raw water, the raw water state is obtained so that a correlation between the fluorescence spectrum intensity and the concentration of the soluble chemical oxygen demand in the database is obtained. Dilution ratio setting means for calculating the dilution ratio of the liquid sample according to
Dilution means for obtaining diluted raw water by mixing dilution water with a liquid sample obtained by continuously sampling the raw water at the dilution ratio calculated by the dilution ratio setting means,
In the diluted raw water, measuring means for measuring the fluorescence spectrum intensity at the excitation wavelength of the peak position;
Using the correlation in the database creation means, from the measurement results in the measurement means, calculate the concentration of the dissolved chemical oxygen demand of the specific oil or specific oil-containing wastewater in the diluted raw water, Further, concentration calculation means for calculating the concentration of the dissolved chemical oxygen demand of the specific oil or the specific oil- containing wastewater in the raw water using the dilution factor;
A device for measuring the concentration of a specific oil in a waste water or a specific oil-containing waste water.
( 9 ) Concentration measurement of specific oil or specific oil-containing wastewater in wastewater according to ( 8 ), wherein the calibration curve is created using an approximate expression represented by the following equation (1): apparatus.
Fluorescence spectrum intensity = a {1-exp (−bC)} + d (1)
(Here, in the above formula (1), a, b and d are constants, and C is the soluble chemical oxygen demand of the oil or oil-containing waste water.)
(10) An apparatus for calculating the concentration of the soluble chemical oxygen demand of the particular oil or a particular oil-containing wastewater in the in the diluted raw water, previously soluble chemical oxygen demand concentration and total chemical oxygen demand by keeping the correlation relationship between the concentration of the amount, and calculates the concentration of total chemical oxygen demand from the concentration of the resulting soluble chemical oxygen demand is calculated, (8) Or the density | concentration measuring apparatus of the specific oil in the waste_water | drain or specific oil-containing waste_water | drain as described in ( 9 ).
( 11 ) One of the influences of solid matter in the fluorescence analysis and the influence of the background of the liquid sample is provided by providing SS removal means for installing a filter as solid matter removal treatment for the raw water or diluted raw water. Alternatively, the concentration measuring apparatus for specific oil or specific oil-containing wastewater in wastewater according to any one of ( 8 ) to ( 10 ), wherein two effects are reduced.
( 12 ) The SS removal means includes means for preventing clogging of the filter by performing periodic backwashing, wherein the SS removal means is characterized in that in the wastewater according to any one of ( 8 ) to ( 11 ) Concentration measuring device for specific oil or specific oil-containing wastewater.
( 13 ) Any one of ( 8 ) to ( 12 ), wherein an appropriate dilution factor calculated according to the raw water condition is an actual dilution factor calculated based on flow rate data. Concentration measuring device for specific oil or specific oil-containing wastewater in wastewater.
( 14 ) Using the concentration measuring device according to any one of ( 8 ) to ( 13 ), a detection unit that issues an alarm when a preset reference value is exceeded, And / or a coping means for coping with the concentration adjustment of the wastewater, and a specific oil in the wastewater or a specific oil-containing wastewater detection device.

  According to the present invention, waste water containing a specific chemical substance or specific waste water is diluted with an appropriate dilution factor calculated according to the raw water state, so far, concentration quenching, excess detection upper limit, pH, background, solid matter Therefore, it can be applied to wastewater in which the fluorescence method and / or the ultraviolet / visible absorption photometry method cannot be applied due to the influence of the coexisting salt. Furthermore, since the SS concentration in the waste water is also diluted by dilution, it is possible to reduce the influence on the detection accuracy due to the blocking and absorption of light by SS or the fluorescence emitted from SS itself. Moreover, clogging due to SS in the drainage pipe is less likely to occur. In addition, pre-treatment such as filters can be added to the drainage system to reduce the effects of background and solid matter, and solid matter treatment combined with dilution can cause clogging of the filter. It becomes difficult. Furthermore, since an appropriate dilution ratio is set, it is possible to measure accurately without wasting water resources.

It is a principle diagram of fluorescence spectrum measurement. It is a block diagram which shows the detection method in the waste_water | drain containing specific chemical substance or specific waste_water | drain based on this invention. It is a figure which shows correlation with A component density | concentration and fluorescence spectrum intensity | strength. It is a figure which shows correlation with A component density | concentration and ultraviolet and visible light absorbency. It is a figure which shows the approximated curve in the correlation of A component density | concentration and fluorescence spectrum intensity | strength. 2 is a three-dimensional excitation / fluorescence spectrum diagram of oil-containing wastewater in Example 1. FIG. 1 is an ultraviolet / visible absorption spectrum diagram of oil-containing wastewater in Example 1. FIG. It is a figure which shows the correlation and soluble curve of the soluble COD density | concentration of the oil-containing wastewater in Example 1, a mixing density | concentration, a component density | concentration, and fluorescence spectrum intensity | strength. It is a figure which shows the correlation of the soluble COD density | concentration of an oil-containing wastewater in Example 1, a mixing density | concentration, a component density | concentration, and an ultraviolet-visible light absorbency, and an approximated curve. It is a figure which shows the time-dependent change before and behind dilution of the fluorescence spectrum intensity | strength and soluble COD density | concentration in Example 1. FIG. It is a figure which shows the correlation of the soluble COD measured value in Example 1, and the soluble COD density | concentration calculated value by this invention. It is a figure which shows the reduction effect of the influence of the background by dilution in Example 1. FIG. It is a figure which shows the correlation of the total COD density | concentration in Example 1, and soluble COD density | concentration. It is a figure which shows the correlation of the total COD density | concentration in Example 1, and the total COD density | concentration calculation value by this invention. It is a figure which shows the change of the fluorescence spectrum intensity by the presence or absence of filtration in Example 3. FIG. It is a figure which shows the time-dependent change of the fluorescence spectrum intensity by the presence or absence of the filter in Example 3. FIG. It is a three-dimensional excitation and fluorescence spectrum figure of the water-soluble cutting oil in Example 4. It is a figure which shows the change of the fluorescence intensity when the pH of the oil-containing wastewater in Example 5 is adjusted. It is a figure which shows the reduction effect of the influence of pH by the dilution in Example 5. FIG. It is a figure which shows the change of the fluorescence intensity when the solid substance density | concentration of the oil containing waste water in Example 6 is adjusted. It is a figure which shows the reduction effect of the influence of the solid substance by the dilution in Example 6. FIG. It is a figure which shows the change of the fluorescence intensity when adjusting the coexistence salt density | concentration of the oil-containing wastewater in Example 7. FIG. FIG. 10 is a graph showing the effect of reducing the influence of the coexisting salt by dilution in Example 7.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

First, FIG. 1 shows a principle diagram of a fluorescence spectrum measuring apparatus using a fluorometric method.
Light 2 (hereinafter referred to as excitation light 2) generated using the xenon lamp 1 as a light source is divided into a monitor cell 4 and a sample cell 5 containing a liquid sample such as waste water to be measured by a beam splitter 3. The excitation light 2 that has entered the monitor-side detector 4 is used as specific photometry. On the other hand, when the sample cell 5 containing the liquid sample is irradiated with the excitation light 2 having a certain wavelength, fluorescence 6 corresponding to the component contained in the liquid sample is generated and detected by the photomultiplier tube 7. Read the spectral intensity (photometric value). In this case, even if multiple components coexist in the liquid sample and emit fluorescence at the same excitation wavelength, if the fluorescence wavelength is different, select the optimal fluorescence wavelength and measure the multiple components separately (Fluorescence spectrum measurement).

  The wavelength of the excitation light 2 can be continuously changed from a wavelength range that can be measured using a general-purpose fluorescence spectrophotometer, that is, 200 nm to 800 nm. The wavelength of the fluorescence 6 is also continuously measured in a wavelength range that can be measured using a general-purpose fluorescence spectrophotometer, that is, 200 nm to 800 nm. When the component to be detected is specified, the wavelength range of excitation light and / or fluorescence can be narrowed.

  In the analysis procedure, the filtrate (liquid sample) after filtering with filter paper is transferred to the sample cell by about 1 to 2 mL, irradiated with excitation light, and the displayed photometric value is recorded. The operation procedure is very simple, and it takes only a few seconds to a few minutes from setting the sample cell to the measuring instrument until an analysis result is obtained.

  The fluorescence spectrum of the target specific chemical substance or specific wastewater is measured in advance, and the excitation wavelength, fluorescence wavelength, and fluorescence spectrum intensity characteristic of the specific chemical substance or specific wastewater are compiled into a database. Furthermore, diluting the target raw water and measuring the fluorescence spectrum intensity at the excitation wavelength and fluorescence wavelength of the aqueous solution (diluted raw water) in which the component concentration of the specific chemical substance or the mixed concentration of the specific wastewater is changed, and the component of the specific chemical substance A correlation or calibration curve between the concentration or the concentration of specific wastewater and the fluorescence spectrum intensity at the excitation wavelength and the fluorescence wavelength is prepared in advance, and the specific in the liquid sample is determined from the fluorescence spectrum intensity at the excitation wavelength and the fluorescence wavelength of the liquid sample. The concentration of chemical substances or the concentration of specific wastewater can be estimated.

  The specific chemical substance is a chemical substance that can be specified as a compound or a drug and emits fluorescence among chemical substances mixed in waste water. Specific drainage refers to wastewater that can be identified as a series of drainage and emits fluorescence. The component concentration represents the concentration of the specific chemical substance contained in the liquid sample, and the contamination concentration represents the concentration of the specific wastewater contained in the liquid sample.

Next, as a reference form, ultraviolet / visible absorption spectrum measurement by ultraviolet / visible absorption photometry will be described.
By applying light of about 200 nm to 800 nm to a liquid sample and measuring the degree of light absorption by the target component in the liquid sample, that is, the absorbance when the light passes through the liquid sample, the concentration of the component is measured. Is a method of quantitatively analyzing

  In the analysis procedure, the filtrate (liquid sample) after filtration with filter paper is transferred to the sample cell by about 1 to 2 mL, irradiated with light, and the displayed absorbance value is recorded. The operation procedure is very simple, and it takes only a few seconds to a few minutes from setting the sample cell to the measuring instrument until an analysis result is obtained.

  The UV / visible absorption spectrum of the specific chemical substance or specific wastewater to be measured is measured in advance, and an absorption wavelength characteristic of the specific chemical substance or specific wastewater is selected. Furthermore, measure the ultraviolet / visible absorbance of the above absorption wavelength for an aqueous solution (diluted raw water) in which the target raw water is diluted and the component concentration of the specific chemical substance or the concentration of the specific wastewater mixed is changed, and the component concentration of the specific chemical substance Or, create a correlation or calibration curve between the contamination concentration of the specific wastewater and the ultraviolet / visible absorbance beforehand, and determine the component concentration of the specific chemical substance in the liquid sample or the contamination concentration of the specific wastewater from the ultraviolet / visible absorbance of the liquid sample. Can be estimated.

  The relationship between the concentration of the specified chemical substance or the concentration of the specified wastewater to be controlled and the UV / visible absorbance conforms to the Lambert-Beer law. Therefore, UV / visible absorption spectrum measurement is required to detect low-concentration components with high sensitivity. In order to detect a high-concentration component by increasing the optical path length at the time and, conversely, exceeding the measurement upper limit of ultraviolet / visible absorbance, it is possible to detect with high accuracy by shortening the optical path length.

  However, since the fluorescence spectrum intensity and ultraviolet / visible absorbance of the fluorometric method may be affected by the fluorescent component and the surrounding properties of the light absorbing component (pH of liquid sample, coexisting salt, SS, etc.), for example, It is desirable to perform a pretreatment for adjusting the pH or the like of the liquid sample to be detected to a certain range. In particular, since the measurement is based on the optical principle, the turbidity and SS of the liquid sample are such that light is blocked / absorbed, fluorescence is emitted from the SS itself, fluorescence spectrum intensity and ultraviolet / visible absorbance. Therefore, it is desirable to reduce the SS concentration. Furthermore, in a liquid contact type detector, SS adheres to the detection part as dirt, making measurement difficult. Therefore, it is desirable to reduce the SS concentration.

  Furthermore, in the fluorometric method, there is a quenching action in which the fluorescence is weakened as the concentration of the component in the liquid sample increases. This is considered to be caused by collision between molecules existing in water or non-collision energy transfer between different or similar excited-unexcited molecules. Because of this action, low-concentration contamination can be detected with high sensitivity in the fluorescence method, but if it is mixed at high concentration, it may be erroneously determined as low-concentration contamination and cannot be detected correctly. .

  In addition, in the UV / visible absorptiometry, there is an upper limit of detection of the measuring device, and when the concentration exceeds a certain level, the absorbance becomes very high (it does not transmit light). Become.

  In the present invention, in applying the principle of the fluorescence photometry and / or ultraviolet / visible absorption photometry as described above, the problem that the specific chemical substance or specific wastewater cannot be measured due to concentration quenching or exceeding the detection upper limit, In order to reduce the influence of SS concentration, pH, background and coexisting salt in the liquid sample, attention was paid to diluting at an appropriate dilution factor calculated according to the raw aqueous state.

In FIG. 2, the structure which shows the detection method in the waste_water | drain containing a specific chemical substance or specific waste_water | drain based on this invention is shown.
The raw water 11 is mixed with specific chemical substances or specific waste water 12. About the specific chemical substance or the specific waste water 12, in the dilution rate setting step 16, a database in the fluorescence photometry and / or the ultraviolet / visible absorption photometry is performed in advance. In the dilution rate setting step 16 based on the database creation step 13, an appropriate dilution rate is determined according to the raw aqueous state. Based on the obtained dilution ratio, in the dilution step 17, the raw water 11 and the dilution water 15 are mixed to obtain a diluted raw water 19. As for the obtained diluted raw | natural water 19, a solid substance is removed by SS removal process 18 as needed. The diluted raw water 19 that has undergone the SS removal step is measured in the measurement step 20 by a fluorescence method and / or an ultraviolet / visible absorption photometry method. A calibration curve or the like is obtained with the correlation 14 based on the database creation step 13, and the COD concentration or the like of the raw water 11 is calculated in the concentration calculation step 21 from the measurement step 20 and the correlation 14. When the obtained COD concentration or the like exceeds a preset target level, an alarm is issued in the detection step 23, and in the coping step 24, measures such as blocking the flow path are performed on site.

  In the database preparation step 13, the data of the fluorescence method and / or the ultraviolet / visible absorption photometry method is made into a database for the specific chemical substance or the specific waste water 12. That is, for a specific chemical substance to be managed or a liquid sample containing a specific wastewater 12 at a high concentration, a fluorescence spectrum measurement and / or ultraviolet / visible absorption spectrum measurement is performed in advance to grasp the fluorescence characteristics and / or ultraviolet / visible absorption characteristics, and fluorescence In the photometric method, the data of excitation wavelength, fluorescence wavelength, and fluorescence spectrum intensity are made into a database, and in the ultraviolet / visible absorption photometry method, the data of excitation wavelength, ultraviolet / visible absorbance are made into a database. Furthermore, it is desirable to measure the COD concentration and / or TOC of specific chemical substances or specific wastewater.

  The correlation 14 is obtained by previously measuring the fluorescence spectrum and / or ultraviolet / visible absorption spectrum of the aqueous solution in which the COD concentration, the component concentration, or the mixed concentration in the specific chemical substance or the specific waste water 12 is changed in the database creation step 13. The correlation between the COD concentration, component concentration, or contamination concentration in the specific chemical substance or specific waste water 12 to be managed and the fluorescence spectrum intensity and / or ultraviolet / visible absorbance at the peak position is obtained, and a calibration curve is obtained. Create and obtain in advance. When obtaining a calibration curve, it is desirable to adjust the pH and remove the solid matter in order to exclude the influence of pH and solid matter.

  Using the calibration curve, in the dilution factor setting step 16 to be described later, the quenching action of the fluorescence method does not occur, and the upper limit of detection of the ultraviolet / visible absorption photometry is not exceeded, and the correlation with the fluorescence spectrum intensity and the ultraviolet / visible absorbance is correlated. It is possible to set a density range in which is seen. In order to set this concentration range, it is necessary to obtain a wide range of concentration data. However, when the variation in the concentration of the actual sample is small, the correlation can be obtained by arbitrarily diluting the actual sample.

  For example, FIG. 3 shows the correlation between the component concentration of the chemical substance A contained in the waste water and the fluorescence spectrum intensity, and linearity with the fluorescence spectrum intensity is seen up to the component concentration of 10 mg / L. Quenching occurs and linearity is not seen. Therefore, when the target raw water 11 contains the chemical substance A exceeding 10 mg / L, the correct concentration cannot be detected unless it is diluted to a concentration range of 10 mg / L or less. That is, when 20 mg / L of chemical substance A is contained in the target wastewater, a value of 1030 mV is detected as the fluorescence spectrum intensity, which is the same as the fluorescence spectrum intensity of chemical substance A of 14 mg / L. , Misjudgment. Therefore, in this case, it is necessary to dilute the target waste water at least twice. Similarly, FIG. 4 shows the correlation between the component concentration of the chemical substance A and the ultraviolet / visible absorbance, but linearity is seen up to the component concentration of 10 mg / L, but when it exceeds that, the upper limit value remains. Also in this case, since 20 mg / L of the chemical substance A cannot be detected correctly, an erroneous determination is made.

  Whether or not there is a correlation between the COD concentration, the component concentration, or the mixed concentration in the specific chemical substance or the specific waste water 12 and the fluorescence spectrum intensity or the ultraviolet / visible absorbance is determined when the desired concentration measurement accuracy is set to 5%. Can be determined based on whether the approximate straight line and the actually measured value are within 5%.

  In addition, fitting may be performed using a curve instead of a linear shape. As the concentration increases, the COD concentration, component concentration, or Care must be taken in the management using this calibration curve because a peaking curve that makes it difficult to see changes in the concentration of contamination is obtained. That is, changes in fluorescence spectrum intensity and ultraviolet / visible absorbance are small on the high concentration side, and it may be difficult to detect abnormal value detection or contamination.

  Therefore, using the fitted approximate curve, the effective range of the calibration curve can be obtained by making it a necessary condition that the measurement concentration fluctuation range occurring within the fluorescence spectrum intensity fluctuation range is within the concentration measurement accuracy range. Can be determined.

  For the curve, for example, an approximate expression represented by Expression (1) can be used.

... Formula (1)

  Here, Fluorescence represents the intensity of the fluorescence spectrum, C represents one of the COD concentration of the specific chemical substance or the specific waste water, the component concentration of the specific chemical substance, or the concentration of the specific waste water mixed, and a, b, and d represent constants, respectively.

  Therefore, since the above-mentioned peak is observed in the curve of the formula (1), it is necessary to determine a range where the quenching action of the fluorometric method does not occur, that is, an effective range of the calibration curve. The reason for this is that if the range in which the quenching action occurs is included in the calibration curve, the change in the fluorescence spectrum intensity decreases as the concentration increases, which affects the analysis accuracy.

  To determine the effective range of the calibration curve, use the fluctuation range of the fluorescence spectrum intensity in the average water quality of the wastewater, obtain the concentration range of the calibration curve corresponding to the fluctuation range, and the concentration range is the desired concentration measurement accuracy. The effective range of the calibration curve can be defined as a range that falls within the range.

  That is, first, the time-lapse data of the target wastewater is collected in advance, and the fluctuation range of the fluorescence spectrum intensity in the average water quality is grasped. For example, if the average water quality is for one week of water quality, obtain data at the time of 3 points or more, for example, 2 days, 4 days, 6 days, and grasp the fluctuation range. Can do. Next, based on the obtained calibration curve, it is ascertained how much the concentration range corresponds to a certain concentration range of the fluorescence spectrum intensity. Next, the concentration measurement accuracy is set, and the range where the concentration range corresponding to the fluctuation range of the fluorescence spectrum intensity at the certain concentration falls within the concentration measurement accuracy can be set as the effective range of the calibration curve.

  For example, FIG. 5 shows a case where the fitting is performed by the equation (1) based on the data of FIG. At this time, the fluctuation range of the fluorescence spectrum intensity in the average water quality was found to be ± 5 mV from the time-lapse data of wastewater collected in advance. At this time, when the range of the desired concentration measurement accuracy is 10%, the concentration range corresponding to the fluctuation range ± 5 mV of the fluorescence spectrum intensity at a certain concentration is obtained as shown in Equation (2).

... Formula (2)

  From this equation, it can be seen that the fluctuation range of fluorescence spectrum intensity ± 5 mV corresponds to the concentration range of 11.2 to 13.1 mg / L at 12 mg / L and 12.0 to 14.4 mg / L at 13 mg / L. It was.

  Next, since the desired concentration measurement accuracy is 10%, it is 10.8 to 13.2 mg / L at 12 mg / L, and 11.7 to 14.3 mg / L at 13 mg / L. At this time, at 12 mg / L, the concentration range corresponding to the fluctuation range of the fluorescence spectrum intensity was within the range of the desired concentration measurement accuracy, and was outside the range at 13 mg / L. Therefore, the effective range of the calibration curve in FIG. 5 is 12 mg / L or less.

  However, in the above method, even in the concentration range of 0 to 0.7 mg / L, the concentration range corresponding to the fluctuation range of the fluorescence spectrum intensity is within the range of the desired concentration measurement accuracy. It can be disregarded because it deviates from the purpose of determining the range where the quenching action of the law does not occur.

  In the correlation 14, a correlation between the soluble chemical oxygen demand and the total chemical oxygen demand is obtained in advance. By using this, it becomes possible to estimate the total chemical oxygen demand from the soluble chemical oxygen demand in the concentration calculation step 21 described later.

  In the dilution factor setting step 16, the dilution factor in the dilution step 17 described later is set based on the correlation 14. The dilution factor varies depending on the specific chemical substance or specific wastewater 12 to be processed, but the fluorescence spectrum intensity, ultraviolet / visible absorbance with respect to the COD concentration, component concentration, or contamination concentration in the specific chemical substance or specific wastewater 12 is a quenching action. It is desirable to dilute to a concentration range where a correlation is observed at a concentration lower than the concentration at which the occurrence of gas is below the upper limit of detection.

  Examples of the purpose of setting the dilution rate include a dilution rate for the purpose of concentration management and a dilution rate for the purpose of detecting abnormal values.

  In the dilution ratio for the purpose of concentration management, the raw water 11 containing the target specific chemical substance or specific waste water 12 is periodically sampled and analyzed, and the specific chemical substance or specific waste water 12 in the raw water 11 Based on the COD concentration, component concentration, or contamination concentration data, the average value and / or the standard deviation can be determined. For example, if the average component concentration of the specified chemical substance A is 27.5 ± 2.5 mg / L by sampling and analysis twice to three times every week for 3 months, 40 mg with a margin of up to 30 mg / L If the measurement range is set up to / L and dilution is performed 4 times, the measurement range of the specified chemical substance A is within 10 mg / L.

  As the dilution factor for the purpose of detecting an abnormal value, an abnormal value of COD concentration, component concentration, or mixed concentration in the target specific chemical substance or specific waste water 12 is set so as to be within the measurement range. decide. For example, when the target abnormal value is set to 80 mg / L, if the dilution factor is set to 10 with a margin, the measurement range of the specific chemical substance A is within 10 mg / L.

  However, for the purpose of concentration management or abnormal value detection, if the average concentration range or the set abnormal value of the raw water is within the effective range of the calibration curve for fluorescence analysis or ultraviolet / visible absorbance, set the dilution factor. Is 1 time, and in the present invention, a dilution factor of 1 is also included.

  Moreover, in order to adjust the appropriate dilution ratio calculated according to the raw water state, it is necessary to keep the flow rate of the incoming raw water 11 and the flow rate of the dilution water 15 constant. For this purpose, it is possible to select a pump that draws the raw water 11 into the analyzer so that the flow rate does not change greatly, or to control the water pressure by using a pressure reducing valve and a constant flow valve in the dilution water 15 to make the flow rate constant. . Furthermore, by monitoring the flow rates of the raw water 11 and dilution water 15 with a flow meter at the same time as the fluorescence spectrum intensity and the ultraviolet / visible absorbance, the dilution factor can be constantly maintained and managed. Regarding the dilution factor, when the analysis accuracy is set to 5%, it can be determined that the change rate of the dilution factor is within 5%. For example, if the dilution factor is set to 5 times, flow rate fluctuations that result in 5 ± 0.25 times dilution are acceptable.

  In the dilution step 17, based on the dilution rate set in the dilution rate setting step 16, the raw water 11 containing the specific chemical substance to be managed or the specific waste water 12 is continuously diluted. The quenching action can be reduced by diluting the raw water 11 containing the specific chemical substance or the specific waste water 12 with the dilution water 15 at a constant magnification. Therefore, it is possible to avoid the erroneous determination that the concentration is low and to detect the correct concentration. In addition, by diluting, the turbidity and SS concentration of the liquid sample can be reduced, so that the influence can be reduced, and when a filter is additionally provided for removing turbidity and SS, The occurrence of clogging can be suppressed.

  As a specific dilution method, there is a method in which the dilution water 15 is united with the raw water 11 continuously flowing in at a constant flow rate. In the dilution water 15, almost no fluorescence spectrum intensity is observed at the peak position of the fluorescence spectrum of the specific chemical substance or specific waste water 12, and almost no ultraviolet / visible absorbance is observed at the peak position of the ultraviolet / visible absorption spectrum. It is desirable to use water with low COD and TOC concentrations. For example, if the analysis error is within 5%, the fluorescence spectrum intensity at the same peak position of the dilution water 15 when the fluorescence spectrum intensity and the ultraviolet / visible absorbance at the peak position of the target specific chemical substance or specified wastewater 12 are 100. If the ultraviolet / visible absorbance is 5 or less, it is acceptable. If the average COD concentration is about 100 mg / L, it is desirable to use dilution water 15 having a COD concentration of less than 10 mg / L, such as tap water and industrial water, and the average COD concentration of the specific chemical substance or specific waste water 12 is 10 mg. If it is about / L, it is desirable to use dilution water 15 such as distilled water having a COD concentration of less than 1 mg / L.

  In the SS removal step 18, the SS component in the raw water 11 is removed by installing a filter in the flow path. By removing the SS component, fluctuations in fluorescence spectrum intensity and ultraviolet / visible absorbance are suppressed and stabilized. Furthermore, the blockage by the SS component of the drain pipe can be suppressed. Although the SS removal level by the filter varies depending on the liquid sample, it is desirable to remove the turbidity to such an extent that the fluorescence spectrum intensity and the ultraviolet / visible absorbance do not change significantly before and after the filtration treatment. For example, if the fluorescence spectrum intensity does not change significantly between a liquid sample filtered through JIS P 3801 with a 5-type A filter paper and a liquid sample obtained by filtering the filtered liquid sample with a 5-type C filter paper, It is considered sufficient to remove turbidity. Regarding changes in the fluorescence spectrum intensity and ultraviolet / visible absorbance due to filtration, for example, if the analysis error is within 5%, it is acceptable if the change is within 5% due to filtration.

  Further, by regularly back-cleaning the filter, the occurrence of clogging is considerably reduced, and the frequency of periodic maintenance operations such as filter cleaning and filter replacement is reduced.

  In the measurement step 20, a fluorescence spectrum and / or ultraviolet / visible absorption spectrum specific to the specific chemical substance or specific wastewater 12 to be managed is selected from the fluorescence property and / or ultraviolet / visible absorption property obtained in the database creation step 13. The fluorescence spectrum intensity and / or ultraviolet / visible absorbance is measured, and the fluorescence spectrum intensity and / or ultraviolet / visible absorbance at the peak position of the fluorescence spectrum and / or ultraviolet / visible absorption spectrum of the target specific chemical substance or specified wastewater 12 is measured. Get.

  Using the calibration curve created in the correlation 14 from the obtained fluorescence spectrum intensity and / or ultraviolet / visible absorbance, the fluorescence spectrum intensity and / or the diluted raw water 19 containing the specified chemical substance or specified waste water 12 to be managed From the ultraviolet / visible absorbance, the COD concentration, component concentration, or contamination concentration in the specified chemical substance or specified waste water 12 to be managed in the diluted raw water 19 obtained by diluting the raw water 11 in the dilution step 17 is estimated. can do.

  However, since the fluorescence spectrum intensity and ultraviolet / visible absorbance of the fluorometric method may be affected by the fluorescent component and the surrounding properties (pH of liquid sample, coexisting salt, SS, etc.), the raw water Depending on the pH variation of 11, it is desirable to add, for example, a pretreatment step for adjusting the pH of the liquid sample to be detected to a certain range.

  In addition, in order to obtain actual measurement data of the dilution rate that may be used in the concentration calculation step 21 described later, two or more of the three flow rate data of the target raw water 11, the dilution water 15, and the diluted raw water 19 are used. taking measurement.

  In the concentration calculation step 21, the concentration of the specific chemical substance or the specific waste water 12 of the diluted raw water 19 obtained in the measurement step 20 is calculated by dividing the flow rate data obtained in the measurement step 20 to obtain a dilution factor. It becomes possible to estimate the COD concentration, the component concentration, or the contamination concentration in the specific chemical substance or specific waste water 12 contained in the target raw water 11. However, the dilution rate set in the dilution rate setting step 16 may be used as long as the flow rate can be controlled to be substantially constant. If the analysis accuracy is set to 5%, it can be determined that the change rate of the dilution factor is within 5%. For example, when the dilution rate is set to 5 times, flow rate fluctuations that result in 5 ± 0.25 times dilution are acceptable.

  Further, the total chemical oxygen demand can be estimated from the solubility chemical oxygen demand using the correlation between the soluble chemical oxygen demand and the total chemical oxygen demand obtained in the correlation 14. .

  In the detection step 23, it is determined whether or not a desired detection level has been exceeded based on the COD concentration, component concentration, or contamination concentration of the target raw water 11 obtained in the concentration calculation step 21. Make it work.

  In the coping process 14, a measure such as blocking the flow path is performed for the alarm operated in the detection process 13.

  In addition, when the specific chemical substance is a flame retardant hydraulic oil or a water-soluble cutting oil, or the specific drainage includes a flame retardant hydraulic oil or a water-soluble cutting oil, the flame retardant hydraulic oil or the water-soluble cutting oil When the fluorescent substance itself emits fluorescence, components other than the flame retardant hydraulic fluid or water-soluble cutting oil may emit fluorescent light, and dilution is necessary when emitting a high fluorescence spectrum intensity. In this case, the concentration of the flame-retardant hydraulic fluid or water-soluble cutting oil can be measured by following the same steps as described above.

(Example 1: Estimation of COD concentration, contamination concentration and component concentration of oil-containing wastewater)
Hereinafter, a method for estimating the COD concentration, the mixing concentration, and the component concentration for the oil-containing wastewater will be described.

  In the database creation step 13 shown in FIG. 2, as shown in FIG. 6, it is clear that there are peaks at (excitation wavelength) / (fluorescence wavelength) = 220 nm / 300 nm, 270 nm / 300 nm as the fluorescence characteristics of the oil-containing wastewater. did. However, since 270 nm / 300 nm is close to the excitation wavelength and the fluorescence wavelength and is strongly influenced by scattered light, 220 nm / 300 nm was selected as the wavelength set used for detection in the measurement step 20 described later.

  Further, as shown in FIG. 7, it was clarified that there are peaks at excitation wavelengths of 220 nm and 260 nm as ultraviolet / visible absorption characteristics of the oil-containing waste water. Since a commercially available analyzer based on ultraviolet / visible absorptiometry is set to 264 nm, the wavelength used for detection is set to 264 nm.

  In the correlation 14 shown in FIG. 2, the fluorescence spectrum and ultraviolet / visible absorption spectrum of the oil-containing wastewater are measured, and the correlation between the COD concentration, contamination concentration and component concentration of the oil-containing wastewater, and the fluorescence spectrum intensity at the peak position, A calibration curve was prepared in advance (FIGS. 8 and 9). For the COD concentration, the following formula (3) was obtained.

... Formula (3)

  For the COD concentration, the actual sample and the actual sample diluted with pure water were adjusted to pH 8, and the fluorescence spectrum intensity and the ultraviolet / visible absorbance were measured for the liquid sample filtered through the 5 C filter paper specified in JIS P 3801. Plotted with actual measured values of COD concentration. Contamination concentration and component concentration were correlated by diluting oil-containing wastewater in stages with pure water. As a result, concentration quenching was observed at a COD concentration of about 50 mg / L or more. Furthermore, the divergence from the formula (3) has increased. This is due to the influence of solids contained in the liquid sample, the influence of pH, the influence of the background, and the quenching action of iron as a coexisting salt on the high COD concentration side. This is because of the large influence. That is, on the low COD concentration side after dilution, the effect of solids, the effect of pH, the effect of background, and the effect of coexisting salts were reduced, so that the deviation from equation (3) was reduced.

  In addition, the fluctuation range of the fluorescence spectrum intensity in the average water quality was found to be ± 7.5 mV from the time-lapse data of wastewater collected in advance. The average water quality was obtained from 50 analytical data obtained over 2 months. At this time, in FIG. 8, the COD concentration ranges corresponding to the fluctuation range ± 7.5 mV of the fluorescence spectrum intensity at a certain concentration are 64.3 to 76.7 mg / L at 70 mg / L, and 68.6 to 75 mg / L. It was found to correspond to a concentration range of 82.6 mg / L.

  Next, since the desired concentration measurement accuracy is 10%, it is 63 to 77 mg / L at 70 mg / L and 67.5 to 82.5 mg / L at 75 mg / L. At this time, at 70 mg / L, the concentration range corresponding to the fluctuation range of the fluorescence spectrum intensity was within the range of the desired concentration measurement accuracy, and was outside the range at 75 mg / L. Therefore, the effective range of the calibration curve in FIG. 8 is 70 mg / L or less.

  Similarly, a correlation was recognized up to a contamination concentration of 7.0% or less and a component concentration of 0.38% or less.

  The concentration range where linearity is observed below the upper limit of detection in the ultraviolet / visible absorptiometry is 0 to 100 mg / L for COD concentration, 0 to 10% for mixed concentration, and 0 to 0.67% for component concentration. Admitted. It was found that measurement could not be performed in the higher concentration range because the detection limit was exceeded.

  From the result obtained from the correlation 14, concentration quenching was observed in the fluorescence spectrum intensity, and the range of the effective calibration curve was limited as compared with the ultraviolet / visible absorptiometry. The dilution factor for reducing the influence of quenching was determined. The abnormal value COD concentration was set to 250 mg / L, the mixing concentration was 34%, the component concentration was set to 1.9%, the curve fitting in the correlation 14 was used, and the dilution rate was 250/70 = 3.57, A 4-fold dilution was made for allowance.

  In the dilution step 17, the oil-containing wastewater was continuously diluted 4 times based on the dilution rate set in the dilution rate setting step 16. Specifically, the raw water flow rate that continuously flows in was set to 2.0 L / min, the fresh water flow rate was set to 6.0 L / min, and they were combined. Fresh water has a fluorescence spectrum intensity at a peak position of 220 nm / 300 nm of about 2.5, and when the analysis error is within 5%, it is 2.5 / 100 = 2.5% compared to the fluorescence spectrum intensity of oil-containing wastewater. Therefore, it can be tolerated. The average COD concentration was 2.7 mg / L, and it was confirmed that there was no problem as dilution water.

  In the measurement process 20, the fluorescence spectrum intensity and / or ultraviolet / visible absorption spectrum intensity at the peak position of 220 nm / 300 nm of the fluorescence spectrum of the oil-containing wastewater obtained in the database preparation process 13 was obtained.

  Using the calibration curve created in the correlation 14, the COD concentration, contamination concentration, and component concentration of the diluted raw water 19 were estimated from the fluorescence spectrum intensity of the diluted raw water 19 in which the oil-containing wastewater was diluted. FIG. 10 shows changes in fluorescence spectrum intensity and estimated COD concentration over time when dilution is not performed and when the dilution is performed, together with the measured COD concentration. As a result, when the dilution was not performed, the wastewater COD concentration from the fluorescence spectrum intensity could hardly be estimated. However, by performing the dilution, the COD concentration of the diluted raw water 9 and the measured COD concentration agree well. I understood that.

  Moreover, in the measurement process 20, the raw | natural water flow volume and the fresh water flow volume were measured.

  In the concentration calculation step 21, the COD concentration, the mixed concentration and the component concentration of the diluted raw water 19 obtained in the measurement step 20 are used as the raw water flow rate measured in the measurement step 20 and the dilution rate calculated each time from the fresh water flow rate. Thus, the COD concentration in the raw water 11 of the oil-containing wastewater was determined. FIG. 11 shows a comparison between the calculated COD concentration of the raw water 11 of the oil-containing wastewater and the measured COD concentration. Moreover, the result of having calculated | required the COD density | concentration in oil-containing drainage source water using the dilution factor 4 times set in the dilution factor setting process 16 for the comparison is shown. As a result, when the dilution rate was fixed at 4 times, the COD concentration calculation value and the COD concentration actual measurement value were better matched when the dilution rate was calculated each time. This is because the pipe may be blocked by the SS component of the raw water flow rate, the set flow rate cannot be kept constant, the flow rate is reduced, and the dilution factor is increased. As a result, due to fluctuations in the dilution factor set in the dilution factor setting step 16, the calculated value of the raw water COD concentration by the set dilution factor deviates from the measured COD concentration, and the raw water COD concentration by the actually measured dilution factor The calculated value was in good agreement with the measured COD concentration.

  In addition, by using the correlation 14, it is possible to estimate the concentration and component concentration of oil-containing wastewater.

  FIG. 12 shows the effect of reducing the influence of the background by performing dilution. Before the dilution, a large fluctuation was observed in the fluorescence intensity, but the influence of the background was reduced, so that the baseline fluctuation was suppressed and the fluorescence spectrum intensity and absorbance were stabilized.

  In the detection step 23, it was determined whether the calculated COD concentration value obtained in the concentration calculation step 21 exceeded the target abnormal value. As a result, on the 35th day in FIG. 10, the calculated COD concentration detected a COD concentration of 300 mg / L in the raw water 11 (75 mg / L in diluted raw water 9), and judged that it was an abnormal value, and the alarm was activated.

  In the coping process 24, after the field worker confirmed the alarm that was activated in the detection process 23, the supply of the oil-containing drainage raw water line was stopped.

(Example 2: Estimation of total chemical oxygen demand)
Hereinafter, a method for estimating the total COD concentration after obtaining the soluble COD concentration for oil-containing wastewater in Example 1 will be described.

  Based on the correlation 14, a correlation between the soluble COD concentration and the total COD concentration is obtained in advance. The result is shown in FIG. Here, it is judged that the soluble COD concentration and the total COD concentration are linear, approximation is performed with a straight line passing through the origin, and the conversion coefficient between the soluble COD concentration and the total COD concentration is obtained by obtaining the slope thereof. . This conversion factor is divided by the calculated COD concentration value obtained in Example 1, that is, the following calculation formula (4) is established to obtain the calculated total COD concentration value.

... Formula (4)

  FIG. 14 shows the correlation between the calculated total COD concentration according to the present invention and the total measured COD concentration obtained from the calculation formula (4). As a result, the estimated value and the measured value agreed well.

(Example 3: Reduction of SS concentration and improvement of detectability by filter)
Hereinafter, in Example 1, the SS removal process 18 is added after the dilution process 17, and the method of estimating the soluble COD concentration for oil-containing wastewater will be described.

  In the SS removal step 18, a filter for removing floating solids in the raw water 11 was installed on the diluted raw water 19 diluted four times in the dilution step 17, and regular backwashing was performed. The filter is selected in advance, and the diluted raw water 19 having a soluble COD concentration equal to the target detected concentration is subjected to a liquid sample that has not been filtered, and a 5-type A filter paper defined in JIS P 3801. The fluorescence spectrum intensity and the absorbance were compared between the filtered liquid sample and the liquid sample obtained by filtering the filtered liquid sample with 5 types C filter paper. As a result, the fluorescence spectrum intensity greatly increased in the filtered liquid sample from the unfiltered liquid sample, and the influence of light blocking / absorption due to the solid removal by the filter was reduced. Further, in the filtered liquid sample, it was confirmed that the fluorescence spectrum intensity of the filtrate was not greatly changed between the 5 type A filter paper and the 5 type C filter paper, and a filter corresponding to the 5 type A filter paper was installed (FIG. 15). reference).

  In addition, by removing the SS by installing a filter, the influence of light blocking / absorption due to the solid substance of the fluorescence spectrum intensity and absorbance is reduced, and further, the influence of the background is reduced, thereby changing the baseline. It was suppressed and the fluorescence spectrum intensity and absorbance were stabilized (see FIG. 16). Furthermore, the frequency of the drainage pipe clogging once a week was suppressed to once a month or more.

  Further, as a result of passing water for one month after installing the filter, it was confirmed that the filter was clogged in about 3 days. Therefore, using the dilution water 15 used in the dilution step 17, it was 1 every 2 hours. Back washing was performed once. By removing solid matter using a filter combined with dilution, the filter replacement time was changed from 3 days to 2 weeks or more, and the replacement frequency was greatly reduced.

(Example 4: Estimating the concentration of water-soluble cutting oil)
Hereinafter, in Example 1, when the said specific chemical substance is a water-soluble cutting oil, the method to estimate the water-soluble cutting oil density | concentration in the waste_water | drain containing a water-soluble cutting oil is demonstrated.

  In the database preparation step 13, as shown in FIG. 17, it was clarified that a peak exists at (excitation wavelength) / (fluorescence wavelength) = 280 nm / 340 to 360 nm as the fluorescence characteristics of the water-soluble cutting oil. Therefore, (excitation wavelength) / (fluorescence wavelength) = 280 nm / 360 nm was selected as the wavelength set used for detection. Further, no ultraviolet / visible light absorption characteristics were observed.

  In correlation 14, as in Example 1, a correlation and calibration curve between the COD concentration and component concentration of the water-soluble cutting oil and the fluorescence spectrum intensity at the peak position were prepared in advance. However, since the raw water 11 and the diluted raw water 19 are stable at about pH 7 and have a small amount of solid components and little influence on the fluorescence analysis, pH adjustment and solid removal should be performed when determining the correlation. Not done.

  The desired component concentration detection level of the water-soluble cutting oil is 0.05 v / v%, and the quenching action of the fluorescence spectrum intensity is not seen in the component concentration range of 0 to 0.1 v / v%, and the linearity is As a result, the effective range of the calibration curve was not determined.

  However, when the fluctuation range of the fluorescence spectrum intensity in the average water quality is ± 5 mV and the desired concentration measurement accuracy range is 5%, the fluctuation range of the fluorescence spectrum intensity is ± 5 mV. Therefore, even if the effective range of the calibration curve was scrutinized, the effective range of the calibration curve was sufficiently satisfied.

  In the dilution factor setting step 16, the dilution factor for the purpose of detecting an abnormal value was determined based on the result obtained from the correlation 14, but the desired detection level was within the effective range of the calibration curve. The raw water 11 was not diluted, that is, the dilution factor was set to 1 and the dilution step 17 was also omitted.

  In the SS removal step 18, since the raw water 11 and the diluted raw water 19 have few solid components and the influence on the fluorescence analysis was small, the SS removal step 18 was also omitted.

  In the measurement process 20, the fluorescence spectrum intensity in the peak position of 280 nm / 360 nm of the fluorescence spectrum of the water-soluble cutting oil obtained in the database preparation process 13 was obtained.

  Using the calibration curve created in the correlation 14, the COD concentration and the component concentration of the water-soluble cutting oil in the wastewater containing the water-soluble cutting oil were estimated from the fluorescence spectrum intensity of the wastewater containing the water-soluble cutting oil. As a result, it was found that the estimated COD concentration value of the water-soluble cutting oil in the waste water was in good agreement with the measured COD concentration value.

  The concentration calculation step 21 was omitted because the raw water 11 was not diluted.

  In the detection step 23, it was determined whether the estimated value of the water-soluble cutting oil concentration obtained in the measurement step 20 exceeded the target abnormal value. As a result, since the estimated component concentration value of the water-soluble cutting oil exceeded 0.05 v / v% on the 10th day, it was judged as an abnormal value and the alarm was activated.

  In the coping process 24, after the field worker confirmed the alarm that was activated in the detection process 23, the supply amount of the raw water line containing the water-soluble cutting oil was reduced.

(Example 5: Reduction of pH effect by dilution)
Hereinafter, the effect of reducing the influence of pH due to dilution will be described by performing a batch test using the oil-containing wastewater in Example 1.

  FIG. 18 shows changes in fluorescence intensity when the oil-containing wastewater is adjusted to pH 3 to 9 with respect to a liquid sample obtained by filtering the oil-containing wastewater with 5 types C filter paper defined in JIS P3801. As a result, it was found that in the oil-containing wastewater, the fluorescence intensity greatly decreased at pH 4 or lower.

  Next, using an oil-containing wastewater having a pH of 4, an effect of reducing the influence of pH by dilution was observed. Specifically, the dissolution obtained by using the correlation 14 in Example 1 from the fluorescence intensity when a liquid sample obtained by filtering oil-containing wastewater having a pH of 4 with 5 type C filter paper defined in JIS P 3801 was diluted 10 times. The soluble COD concentration was multiplied by a dilution factor of 10 and compared with the measured soluble COD concentration.

  FIG. 19 shows the examination results. At pH 4, the fluorescence intensity greatly decreased as in FIG. 18. As a result of calculating the soluble COD concentration based on this fluorescence intensity, it was 17.5 mg / L. On the other hand, the liquid sample having a pH of about 5 was measured by 10-fold dilution, and the soluble COD concentration was calculated based on the obtained fluorescence intensity. As a result, it was 5.7 mg / L. By multiplying this value by 10 times the dilution rate, the calculated soluble COD concentration was 57 mg / L. Further, the actually measured value of the soluble COD concentration at this time was 58.8 mg / L.

  From the above results, it was possible to reduce the influence of pH by performing dilution, and to improve the concentration measurement accuracy of the soluble COD concentration.

  The same can be said for the ultraviolet / visible absorptiometry.

(Example 6: Reduction of influence of solid substance by dilution)
Hereinafter, the reduction effect of the influence of the solid substance by dilution is demonstrated by performing a batch test using the oil-containing wastewater in Example 1. FIG.

  FIG. 20 shows changes in fluorescence intensity when the solid concentration is adjusted by mixing the oil-containing wastewater adjusted to pH 8 and the oil-containing wastewater filtrate. As a result, in the oil-containing wastewater, it was found that the fluorescence intensity decreased as the solid concentration increased.

  Next, using an oil-containing wastewater having a solid concentration of 360 mg / L, the effect of reducing the influence of the solid by dilution was observed. Specifically, for a liquid sample in which a solid substance concentration of 360 mg / L of oil-containing wastewater was adjusted to pH 8, from the fluorescence intensity when diluted 10 times, to the soluble COD concentration determined using the correlation 14 in Example 1 Multiply by a dilution factor of 10 and compare with the measured dissolved COD concentration.

  FIG. 21 shows the examination results. At a solid matter concentration of 360 mg / L, the fluorescence intensity decreased as in FIG. 20. As a result of calculating the soluble COD concentration based on this fluorescence intensity, it was 1.9 mg / L. On the other hand, the liquid sample having a pH of about 5 was measured by performing 10-fold dilution, and the soluble COD concentration was calculated based on the obtained fluorescence intensity. As a result, it was 4.7 mg / L. By multiplying this value by 10 times the dilution factor, the calculated soluble COD concentration was 47 mg / L. Further, the actually measured value of the soluble COD concentration at this time was 58.8 mg / L.

From the above results, it was possible to reduce the influence of solid matter by performing dilution, and to improve the concentration measurement accuracy of the soluble COD concentration.

  The same can be said for the ultraviolet / visible absorptiometry.

(Example 7: Reduction of influence of coexisting salt by dilution)
Hereinafter, the effect of reducing the influence of the coexisting salt due to dilution will be described by performing a batch test using the oil-containing wastewater in Example 1.

  FIG. 22 shows the fluorescence intensity when adjusting the concentration of the coexisting salt by adding soluble iron as coexisting salt to the oil-containing wastewater adjusted to pH 8 and filtered with JIS P 3801 as specified in Class 5 C filter paper. Showing change. As a result, it was found that the fluorescence intensity decreased in the oil-containing wastewater as the concentration of the coexisting salt increased. However, the oil-containing wastewater does not contain soluble iron, which is a coexisting salt, so as to affect the fluorescence intensity.

  Next, using an oil-containing wastewater having a coexisting salt concentration of 100 mg / L, an effect of reducing the influence of the coexisting salt by dilution was observed. Specifically, from the fluorescence intensity when diluted 10-fold with respect to a liquid sample prepared by adjusting oil-containing wastewater having a coexisting salt concentration of 100 mg / L to pH 8, and filtered through 5 types C filter paper defined in JIS P 3801, Example 1 The soluble COD concentration obtained using the correlation 14 in FIG. 5 was multiplied by a dilution factor of 10 and compared with the actually measured soluble COD concentration.

  FIG. 23 shows the examination results. At the coexisting salt concentration of 100 mg / L, the fluorescence intensity decreased as in FIG. 22. As a result of calculating the soluble COD concentration based on this fluorescence intensity, it was 27.4 mg / L. On the other hand, the liquid sample having a pH of about 5 was measured by 10-fold dilution, and the soluble COD concentration was calculated based on the obtained fluorescence intensity. As a result, it was 4.9 mg / L. By multiplying this value by 10 times the dilution factor, the calculated soluble COD concentration was 49 mg / L. Further, the actually measured value of the soluble COD concentration at this time was 58.8 mg / L.

From the above results, it was possible to reduce the influence of the coexisting salt by performing dilution, and to improve the concentration measurement accuracy of the soluble COD concentration.

  The above results were the same for the ultraviolet / visible absorptiometry.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Xenon lamp 2 Excitation light 3 Beam splitter 4 Monitor side detector 5 Sample cell 6 Fluorescence 7 Photomultiplier tube 8 Processor 11 Raw water 12 Specific chemical substance or specific waste water 13 Database production process 14 Correlation 15 Water for dilution 16 Dilution rate setting process 17 Dilution process 18 SS removal process 19 Diluted raw water 20 Measurement process 21 Concentration calculation process 22 Effluent water 23 Detection process 24 Countermeasure process 25 Concentration measurement method 26 Countermeasure method

Claims (14)

In the method carried out using a specific fluorescence particular oil or a particular oil-containing wastewater, the concentration measurement of the particular oil or a particular oil-containing wastewater is mixed in the raw water,
The specific oil is a flame retardant hydraulic oil or a water-soluble cutting oil, and the specific oil-containing wastewater is a drainage containing a flame retardant hydraulic oil or a water-soluble cutting oil,
A fluorescence spectrum is measured for the specific oil or a liquid sample containing a specific oil-containing wastewater in the entire excitation wavelength range of 200 to 800 nm, and the excitation wavelength and the fluorescence wavelength at the peak position of the fluorescence spectrum intensity of the specific oil or the specific oil-containing wastewater. And create a calibration curve by obtaining the correlation between the fluorescence spectrum intensity at the peak position and the concentration of the soluble chemical oxygen demand in the specific oil or specific oil-containing wastewater. A correlation between the fluorescence spectrum intensity and the concentration of the soluble chemical oxygen demand in the database generation process is obtained for the liquid sample obtained by continuously sampling the database and the raw water. In addition, a dilution ratio setting step for calculating the dilution ratio of the liquid sample according to the raw aqueous state,
A dilution step of obtaining diluted raw water by mixing dilution water with a liquid sample obtained by continuously sampling the raw water at the dilution rate calculated in the dilution rate setting step;
In the diluted raw water, a measurement step of measuring the fluorescence spectrum intensity at the excitation wavelength of the peak position;
Using the correlation in the database creation step, from the measurement result in the measurement step, calculate the concentration of the soluble chemical oxygen demand of the specific oil or specific oil-containing wastewater in the diluted raw water, Furthermore, a concentration calculation step for calculating the concentration of the dissolved chemical oxygen demand of the specific oil or the specific oil- containing wastewater in the raw water using the dilution factor;
A method for measuring the concentration of a specific oil in a wastewater or a specific oil-containing wastewater. The method for measuring the concentration of specific oil in wastewater or specific oil-containing wastewater according to claim 1, wherein the calibration curve is created using an approximate expression represented by the following formula (1).
Fluorescence spectrum intensity = a {1-exp (−bC)} + d (1)
(Here, in the above formula (1), a, b and d are constants, and C is the soluble chemical oxygen demand of the oil or oil-containing waste water.) In the method of calculating the concentration of the soluble chemical oxygen demand of the specific oil or the specific oil-containing wastewater in the diluted raw water,
By calculating the correlation between the concentration of the soluble chemical oxygen demand and the concentration of the total chemical oxygen demand in advance, the total chemical oxygen demand is calculated from the calculated concentration of the soluble chemical oxygen demand. The method for measuring the concentration of a specific oil in a wastewater or a specific oil-containing wastewater according to claim 1 or 2, wherein the concentration of the required amount is calculated .   By providing an SS removal step in which a filter is installed as a solid matter removal treatment for the raw water or diluted raw water, one or two of the influence of solid matter in the fluorescence analysis and the influence of the background of the liquid sample are included. The method for measuring the concentration of a specific oil in a wastewater or a specific oil-containing wastewater according to any one of claims 1 to 3, wherein the influence is reduced.   5. The specific oil in the wastewater or the specific oil-containing wastewater according to claim 1, wherein the SS removal step is performed by periodically performing backwashing to prevent clogging of the filter. Concentration measurement method. The specific dilution rate calculated according to the raw water state uses an actual dilution rate calculated based on flow rate data, and the identification in waste water according to any one of claims 1 to 5 , Of concentration of oil or specific oil-containing wastewater. Using the concentration measurement method according to any one of claims 1 to 6 , a detection step of issuing an alarm when a preset reference value is exceeded,
A method for detecting a specific oil in a waste water or a specific oil-containing waste water, comprising: a coping process for performing a coping process for limiting the supply of waste water and / or adjusting the concentration of waste water. In the apparatus for performing it, the concentration measurement of the particular oil or a particular oil-containing wastewater is mixed in the raw water using a specific fluorescence particular oil or a particular oil-containing wastewater,
The specific oil is a flame retardant hydraulic oil or a water-soluble cutting oil, and the specific oil-containing wastewater is a drainage containing a flame retardant hydraulic oil or a water-soluble cutting oil,
The fluorescence spectrum is measured for the specific oil or the liquid sample containing the specific oil-containing wastewater in the entire excitation wavelength range of 200 to 800 nm, and the excitation wavelength and the fluorescence wavelength at the peak position of the fluorescence spectrum intensity of the specific oil or the specific oil-containing wastewater. And create a calibration curve by obtaining the correlation between the fluorescence spectrum intensity at the peak position and the concentration of the soluble chemical oxygen demand in the specific oil or specific oil-containing wastewater. Databaseization means,
For a liquid sample obtained by continuously sampling the raw water, the raw water state is obtained so that a correlation between the fluorescence spectrum intensity and the concentration of the soluble chemical oxygen demand in the database is obtained. Dilution ratio setting means for calculating the dilution ratio of the liquid sample according to
Dilution means for obtaining diluted raw water by mixing dilution water with a liquid sample obtained by continuously sampling the raw water at the dilution ratio calculated by the dilution ratio setting means,
In the diluted raw water, measuring means for measuring the fluorescence spectrum intensity at the excitation wavelength of the peak position;
Using the correlation in the database creation means, from the measurement results in the measurement means, calculate the concentration of the dissolved chemical oxygen demand of the specific oil or specific oil-containing wastewater in the diluted raw water, Further, concentration calculation means for calculating the concentration of the dissolved chemical oxygen demand of the specific oil or the specific oil- containing wastewater in the raw water using the dilution factor;
A device for measuring the concentration of a specific oil in a waste water or a specific oil-containing waste water. 9. The concentration measuring device for specific oil in waste water or specific oil-containing waste water according to claim 8 , wherein the calibration curve is created using an approximate expression represented by the following formula (1).
Fluorescence spectrum intensity = a {1-exp (−bC)} + d (1)
(Here, in the above formula (1), a, b and d are constants, and C is the soluble chemical oxygen demand of the oil or oil-containing waste water.) In the apparatus for calculating the concentration of the soluble chemical oxygen demand of the specific oil or the specific oil-containing wastewater in the diluted raw water,
By calculating the correlation between the concentration of the soluble chemical oxygen demand and the concentration of the total chemical oxygen demand in advance, the total chemical oxygen demand is calculated from the calculated concentration of the soluble chemical oxygen demand. The concentration measuring apparatus for specific oil or specific oil-containing wastewater in wastewater according to claim 8 or 9 , wherein the concentration of the required amount is calculated . By providing SS removal means for installing a filter as solid matter removal treatment for the raw water or diluted raw water, one or two of the influence of solid matter in the fluorescence analysis and the influence of the background of the liquid sample The concentration measuring device for specific oil or specific oil-containing wastewater in wastewater according to any one of claims 8 to 10 , wherein the influence is reduced. The specific oil or specific in waste water according to any one of claims 8 to 11 , wherein the SS removing means includes means for preventing clogging of the filter by performing periodic back washing. Concentration measuring device for oil-containing wastewater. The appropriate dilution factor calculated according to the raw water state uses an actual dilution factor calculated based on flow rate data, and is specified in waste water according to any one of claims 8 to 12. For measuring concentration of oil or specific oil-containing wastewater. Using the concentration measuring device according to any one of claims 8 to 13 , a detection unit that issues an alarm when a preset reference value is exceeded,
Coping means for coping with limiting the drainage supply and / or adjusting the drainage concentration;
A device for detecting a specific oil in a waste water or a specific oil-containing waste water.