JP2982999B2 - Method for detecting concentration of slime control agent over time in papermaking water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for detecting the concentration of a slime control agent contained in water for papermaking, which changes over time, with time.

[0002]

2. Description of the Related Art Conventionally, papermaking water has played an important role in many industrial fields. In many cases, papermaking water is used to improve the quality of water according to the purpose of use or to supply raw materials for reactions. And various additives. For example, cooling water, which is most frequently used in papermaking water, contains various additives such as anticorrosives, scale inhibitors, slime control agents, and the like. Raw materials used remain. And
In order to make the most of the effects of additives in papermaking water, or to recycle used wastewater and make effective use of the remaining raw materials when reusing, trace the concentration of those additives over time. That is an important issue.

[0003] However, depending on the type of the additive, the concentration of water in the water cannot be measured, or even if it can be measured, the operation is complicated or requires a long time, so that the operation of the plant is difficult. It may not be practical for management.

[0004] For this reason, it has been practiced to predict the concentration change of the additive by computer simulation from the amount of water retained in the system and the amount discharged to the outside, but until the additive reaches the end of the flowing water system. However, in addition to various factors, there are unexpected outflow routes, and in many cases, the concentration of the additive is not maintained, which actually causes various problems.

[0005]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is to check the concentration of a slime control agent in papermaking water quickly and accurately at an arbitrary place and time. The purpose of the present invention is to provide a method for efficiently using the information.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, even if the amount of fluorescent substance is very small, use of a fluorescence spectrophotometer or an HPLC equipped with a fluorescence detector. By the detection method, it can be detected with extremely high sensitivity. Therefore, by allowing the additive to accompany the fluorescent substance 2-aminopyridine as a tracer,
They found that the concentration of the slime control agent could be tracked over time, and based on this finding, completed the present invention.

That is, according to the present invention, when the change in the concentration of the slime control agent contained in the papermaking water is tracked over time, 2-aminopyridine is added as a tracer together with the slime control agent, and the concentration is measured by a fluorescence detection method. An object of the present invention is to provide a method for detecting the concentration of a slime control agent over time, which comprises measuring the concentration of the slime control agent over time.

In the method of the present invention, it is necessary to use 2-aminopyridine as a tracer. About this tracer, (1) It is a low toxic substance,
(2) it does not remain in the papermaking water or its residual amount is negligibly small; (3) it is not corrosive to metallic materials; (4) it does not affect the final product; 2-Aminopyridine must satisfy the conditions of (5) being chemically stable and (6) being easily quantified without being disturbed by dissolved substances. Are all satisfied. That is, 2-aminopyridine is a low-toxicity compound used as an intermediate material for pharmaceuticals, for example, a material for antihistamines. 2-Aminopyridine added to papermaking water can be detected with extremely high sensitivity by a fluorescence detection method. As a specific detection method, for example, a method using a fluorescence spectrophotometer, HPLC with a fluorescence detector, or the like can be mentioned.

In the method of the present invention, 2-aminopyridine as a tracer may be mixed with an appropriate amount of a slime control agent to be added to the system and added together with the slime control agent. It may be added separately from the agent. From the calibration curve data shown in Table 1 and the calibration curve shown in FIG. 1, the amount of 2-aminopyridine added was determined from 0.002441406 ppm to 1.25 p.
Since extremely good linearity is exhibited in the range of pm, it may be added so as to have a concentration in this range. The above calibration curve was obtained by adding 2-aminopyridine to papermaking white water collected from a certain papermaking company, and using HPLC equipped with a fluorescence detector. Column: ODS 4.6 mm × 30 cm Solvent: 50% methanol 0.1% Acetic acid Flow rate: 0.8 mL / min Detection: Fluorescence detector Ex310 nm Em370 nm Sample: Centrifugally filtered white water was used as it was.

[0010]

[Table 1]

From the calibration curve data shown in Table 1,
The detection limit for -aminopyridine is estimated to be 2.4 ppb or less.

According to the method of the present invention, it is possible to detect the concentration of a slime control agent in water that is difficult to measure, and it is possible to perform necessary concentration management by tracking this concentration over time.

[0013]

According to the method of the present invention, by using 2-aminopyridine as a tracer, it is possible to quickly and accurately check the concentration of a slime control agent in papermaking water at any place and time. The concentration of the slime control agent can be efficiently controlled.

[0014]

Next, the present invention will be described in more detail by way of examples.

REFERENCE EXAMPLE 1 Stability test of 2-aminopyridine in papermaking company white water The stability of 2-aminopyridine in papermaking whitewater was confirmed for the purpose of controlling the concentration of a slime control agent added to a papermaking machine. It was assumed that a sample for analysis was collected on the day of drug addition using an actual machine and transported to an analysis facility under refrigerated conditions. Therefore, to reproduce this condition,
2-Aminopyridine was added to the papermaking white water to a concentration of 0.85 ppm, and left in a constant temperature oven at 40 ° C. for 8 hours.
Thereafter, the samples were stored in a refrigerator and the concentration of 2-aminopyridine was determined over time. The results are shown graphically in FIG.

As can be seen from FIG. 2, 2-aminopyridine is extremely stable up to 7 days after treatment, and therefore 2-aminopyridine is effective in adding to papermaking white water and controlling the drug concentration. Was confirmed.

Reference Example 2 Influence test of 2-aminopyridine on paper 2-aminopyridine was added to two types of papermaking raw materials of Company A in a large excess compared to the practically detected concentration, and was actually tested using a TAPPI papermaking tester. Paper was made. The concentration of 2-aminopyridine contained in the waste liquid after papermaking was quantified, and the results are shown in Tables 2 and 3.

The displacement of hue due to the addition of a chemical was measured using a lightning digital Hunter whiteness meter for the paper products. Table 4 shows the results. In the table, 2-AP is 2
-Is an abbreviation for aminopyridine.

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

From the above results, 2-aminopyridine is
It can be seen that when 5, 10, and 20 ppm are added to the raw materials, respectively, it can be recovered well. Therefore, the possibility of specific adsorption to papermaking raw materials is not considered. Also, no difference was observed in hue, and it was judged that there was no effect on the papermaking.

REFERENCE EXAMPLE 3 Simple actual machine test A simple actual machine test was performed on a papermaking machine. An outline is shown in FIG. Using a pump 2 from a water intake tank 1 storing tap water, the tap water is introduced into a 20-liter bucket 3 equipped with a stirrer 4 to which 2-aminopyridine has been previously added.
The water in the bucket overflows and the concentration of 2-aminopyridine inside decreases gradually. The decrease in the 2-aminopyridine concentration was determined over time, and the flow rate of the pump, that is, the amount of water flowing out due to overflow was calculated. The concentration of 2-aminopyridine was determined by filtering tap water collected from inside a bucket and injecting 5 microliters of the filtrate into HPLC.

(1) Measurement of Pump Flow Rate and Results of Quantification of 2-Aminopyridine Table 5 shows the measured values of the pump flow rate. The average of the eleven measurements is 1.5552 liters / minute. Table 6 and FIG. 4 show changes in the concentration of the added 2-aminopyridine over time. As can be seen from FIG. 4, a very high level of quantitative result was obtained with a coefficient of 0.999 when the correlation with the polynomial was calculated. Therefore, it is considered that the method can be used sufficiently for controlling the concentration of a drug in flowing water.

[0025]

[Table 5]

[0026]

[Table 6]

(2) Calculation of pump flow rate From Table 6, 2-aminopyridine was 1.3 in the first 2 minutes.
It has decreased from 328 ppm to 1.1430 ppm. So there is a 12.695% reduction in 2 minutes,
Since the capacity of the bucket is 20 liters, it means that 3.1459 liters are flowing out. Therefore, the average flow rate per minute is calculated to be 1.5730 liters. This value is in good agreement with the actual measured value of the pump flow rate of 1.5552 liter / min.

Example 1 The paper machine of Company A was operated under the temporary addition (short-time addition) treatment of the slime control agent commonly used in Company A, except that the slime control agent was accompanied by this tracer. We conducted a test to verify the effect of this tracer. That is, 2-aminopyridine of a 10% aqueous solution was added to the system from the seed box using a metering pump at a flow rate of 150 ml / min together with the slime control agent for 30 minutes, and immediately after that, the papermaking white water was sampled and contained. The aminopyridine concentration was measured. Table 7 shows the measurement results of the 2-aminopyridine concentration. Further, from this, the time course of the concentration of the slime control agent is calculated as shown in Table 7 from the concentration ratio and the specific gravity difference between the 2-aminopyridine of the 10% aqueous solution and the 100% concentration of the slime control agent.

[0029]

[Table 7]

Example 2 The tracer of this tracer for a long time was prepared in the same manner as in Example 1 except that the flow rate of the 2-aminopyridine aqueous solution and the addition times of the aqueous solution and the slime control agent were changed to 47 ml / min and 480 min, respectively. The effect of semi-continuous addition was verified.
Table 8 shows the measurement results of the 2-aminopyridine concentration.
In addition, the change in the concentration of the slime control agent over time was confirmed by comparing 2-aminopyridine in a 10% aqueous solution with 100%
It is calculated as shown in Table 8 from the concentration ratio of the slime control agent and the specific gravity difference.

[0031]

[Table 8]

Example 3 Using the ability to detect 2-aminopyridine aqueous solution with high sensitivity, it was confirmed how much slime control agent was accumulated in paper mill effluent and how much it changed depending on the addition method. Company A paper machine, 10% aqueous solution 2-
Aminopyridine 150m from seed box using metering pump
The same temporary addition as in Example 1 was carried out for 30 minutes together with the slime control agent at a flow rate of 1 / min, and immediately thereafter, 2-aminopyridine in the microorganism treatment tank (activated sludge tank) located at the end of the drainage system The concentration was measured over time. Further, the same semi-continuous addition as in Example 5 was performed in a paper machine of Company A, and the concentration of 2-aminopyridine was measured over time in the same manner as described above. Table 9 shows the results of these measurements together with changes in the concentration of the slime control agent calculated therefrom.
Shown in

[0033]

[Table 9]

Thus, in this plant, when the chemical addition method is semi-continuous, the bulking phenomenon of activated sludge which is considered to be caused by the addition of the slime control agent occurs. It can be seen that this phenomenon can be eliminated by switching. Conventionally, such an accurate concentration measurement has never been possible by a temporary addition method in which only such a low concentration of the slime control agent is discharged.

[Brief description of the drawings]

FIG. 1 is a graph showing an example of a calibration curve of 2-aminopyridine.

FIG. 2 is a graph showing an example of the stability of 2-aminopyridine.

FIG. 3 is a schematic diagram of a simple actual machine test in Reference Example 3.

FIG. 4 is a graph showing the change over time in the concentration of 2-aminopyridine in Reference Example 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake tank 2 Pump 3 Bucket 4 Stirrer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-1105093 (JP, A) JP-A-1-172754 (JP, A) JP-A-5-255253 (JP, A) JP-A-5-255253 277491 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 33/18 G01N 31/00

Claims (1)

(57) [Claims] 1. In tracking the concentration change of a slime control agent contained in papermaking water over time, 2-aminopyridine is added as a tracer together with the slime control agent, and the concentration is measured over time by a fluorescence detection method. A method for detecting the concentration of a slime control agent over time by detecting the concentration of the slime control agent.