KR100271563B1 - Device for detecting bromate and water treatment system using the same - Google Patents

Abstract

The present invention relates to a water treatment technology, and more particularly, to a bromate detection device and a water treatment system using the same, and a bromate detection device having a simple structure and capable of micro analysis, and a micro analysis using the same, and continuous bromate We want to provide a water treatment system that can measure, monitor and control. In the present invention, the absorbance analysis method using a flow injection anlysys (FIA) system for the detection of a small amount of bromate was employed. In addition, the structure of the bromate detection device is simplified in the present invention. A characteristic bromate detection device provided from the present invention comprises a chloropromazine / hydrochloric acid mixing reagent and selective inlet means for selectively introducing sample water into the mixing means; The mixing means for mixing the mixing reagent and the distilled or sample water; Absorbance analysis means for detecting bromate in the mixed solution provided through the mixing means; And control means for controlling the selective inflow means.

Description

Bromate detection device and water treatment system using the same

TECHNICAL FIELD The present invention relates to water treatment technology, and more particularly, to a bromate detection device and a water treatment system using the same.

Ozone oxidation treatment technology using the oxidizing power of ozone (O ₃ ) has an excellent effect on the removal of pollutants such as hardly decomposable substances, excellent removal effect on organic substances in the water, and the biodegradability of the biodegradability is increased It can be expected to increase the efficiency by the OH radical, which is an intermediate product of the increase and the ozone oxidation.

Due to the advantages of the ozonation treatment technology, developed countries have recently applied ozone oxidation treatment technology to water purification process in order to make tap water cleaner and safer, and its use is widely spread. In Korea, there are many movements to use ozone oxidation technology for water treatment due to several sources of water pollution and untrusted tap water. As a result, it is urgent to secure application and operation technologies related to ozone oxidation treatment. It is becoming.

However, in order to apply such ozonation treatment technology to the water treatment process, it is necessary to secure bromate (BrO ₃ ⁻ ) related technology. Bromate is a substance produced by oxidation of bromide (Br ⁻ ) in water, and may be produced by other oxidation treatment processes such as chlorine oxidation as well as ozone oxidation, and is known to be highly toxic to the human body. Therefore, developed countries including the United States treat bromate generation as a very serious problem in the treatment of water, and the movement of regulating the concentration of bromate in water to a low concentration of less than 10ppb is urgently prepared to take measures.

However, the development of a technology capable of detecting such low concentrations of bromate has not progressed significantly. Recently, a bromate detection technology using a flow injection analysis (FIA) system is emerging, but its structure is complicated and difficult to maintain and maintain, and it is impossible to continuously measure, monitor and control bromate. have. Moreover, in terms of bromate's microanalytic ability, the level is still low at home and abroad.

The present invention provides a bromate detection device having a simple structure and capable of microanalysis.

In another aspect, the present invention is to provide a water treatment system capable of microanalysis using the bromate detection device, the continuous measurement, monitoring and control of the bromate.

1 is an illustration of a bromate detection device according to the present invention.

2 is an exemplary diagram of an ozone oxidation treatment system using the bromate detection apparatus of FIG. 1.

Figure 3 is a graph showing the bromate production inhibitory results according to the ammonia concentration.

* Explanation of symbols for the main parts of the drawings

10: Capacity variable chemical pump 11: Teflon reaction coil

12 visible light spectrophotometer detector 13 sample injection loop

14: control computer

Characteristic bromate detection device provided from the present invention to achieve the above technical problem is a chloropromazine / hydrochloric acid mixing reagent and selective inlet means for selectively introducing the sample water into the mixing means; The mixing means for mixing the mixing reagent and the distilled or sample water; Absorbance analysis means for detecting bromate in the mixed solution provided through the mixing means; And control means for controlling the selective inflow means.

In addition, a characteristic water treatment system provided from the present invention to achieve the above technical problem is a chamber for oxidizing the influent; Selective inlet means for selectively introducing the chloropromazine / hydrochloric acid mixed reagent and the sample water discharged from the chamber into the mixing means; The mixing means for mixing the mixing reagent and the sample water; Absorbance analysis means for detecting bromate in the mixed solution introduced from the mixing means; Control means for controlling said selective inlet means; And bromate production inhibitory means for providing a bromate production inhibitory substance to the influent in response to the control means.

For continuous measurement, monitoring and control of bromates, a technique is required to analyze bromates to several ppb levels below the regulatory concentration. In general, ion chromatography has been used for bromate analysis, and spectrophotometric method through color development has also been used in some cases.

The ion chromatography method requires a considerable amount of time for analysis, making it difficult to detect bromate in real time, and due to the influence of interference of other anions, it is practically inappropriate to be applied to a bromate detection device. In comparison, the absorbance analysis method has a short analysis time and has an advantage of easy automation using the FIA system. Table 1 below compares the two methods for bromate analysis.

Ion chromatography Absorbance analysis -Difficult to detect bromate in real time-Not easy to analyze trace-It may happen that it can't be detected due to interference of other negative ions-It requires a lot of repetition time when analyzing a large amount of sample Not easy -Real-time detection of bromate-Relatively good trace analysis-Only independent and selective bromate detection-Small repetition time required for analysis of large samples-Multiple analysis-Easy to automate and commercialize

Therefore, in the present invention, the absorbance analysis method using the FIA system was employed for the trace detection of bromate. In addition, the structure of the bromate detection device is simplified in the present invention.

Hereinafter, preferred embodiments of the present invention will be introduced so that those skilled in the art may easily implement the present invention.

1 is a view illustrating an exemplary bromate detection apparatus according to the present invention.

Bromate can be detected at 530 nm wavelength using a visible light spectrophotometer (visible detector) because the derivative produced by the reaction with chloropromazine under acidic pH conditions will develop a blue color in the visible range .

Inhalation, reaction and measurement of the sample water are continuously carried out through the device as shown in FIG. 1. First, sample water, distilled water and chloropromazine / hydrochloric acid are supplied through the variable-variable chemical pump 10. (HCl) mixed reagent is continuously introduced into the analysis system.In the analysis standby state, the sample water is simply thrown out of the analysis system, and in the analysis system, distilled water and mixed reagent flow. It is mixed enough during the passage.

The analysis standby state is a preparatory step for sample analysis, and the visible light spectrophotometer detector 12 continuously displays a base line signal. In this state, only distilled water is mixed with the mixed reagents, and thus no color development occurs. Therefore, no absorption is maintained, and thus the baseline signal is maintained and is in a ready state.

The sample auto-injection loop 13 operated at a predetermined time interval injects the sample water into the analysis system by changing the path of the sample water and the distilled water at a predetermined time instantaneously. Distilled water continuously flows through the analysis system, and when sample water is momentarily injected, the flow of distilled water is changed into the sample water and reacts with the mixed reagent. If even a small amount of bromate is present in the sample water, the mixture is mixed with the mixed reagent and sufficiently reacts while passing through the Teflon reaction coil 11, and the color is absorbed by the visible light spectrophotometer detector 12, thereby exceeding the baseline signal. Will print If little bromate is present in the sample water, no reaction will occur and the baseline signal will be maintained as distilled water flows. After a specified time, the sample auto-injection loop 13 again changes the flow into distilled water instead of sample water and outputs a baseline signal again for the next analysis.

Operation control of the sample injection loop 13 is made in the control computer 14, and each time the signal output from the visible light spectrophotometer detector 12 is continuously stored in the control computer 14, and the signal is constant. If it is larger than the set value, a warning signal or the like is stopped to stop the ozone supply, or the NH ₄ Cl / H ₂ SO ₄ injection pump (not shown) is operated to suppress the bromate formation.

Using the bromate detection apparatus of the present invention as described above, when bromate is present in the sample water, the chloropromazine reagent reacts selectively with the bromate under acidic pH conditions, thereby reducing the sensitivity of the analysis without being affected by interference of other ions. You can increase it.

The bromate detection device enables bromate detection to a concentration of 1 ppb or less at only 0.15AUFS (AUto Full Scale) of the recorder, even by the signal-to-noise ratio (S / N ratio). In the total flow rate, the concentration of chloropromazine is adjusted to 100 mg / L, the concentration of HCl to 1.32 molar concentration, and the rotational speed of the peristatic pump used as the variable-volume chemical pump 10 is 32 RPM ( revolution per minute) and the concentration of chloropromazine / hydrochloric acid reagent can be adjusted according to the amount of sample.

2 is a diagram illustrating an ozone oxidation treatment system using the bromate detection apparatus of FIG. 1.

The system adds a feedback path for bromate control to the basic flow of influent, ozone oxidation chamber 20, and effluent. The bromate detection device 21 is configured to remove the effluent flowing out of the ozone oxidation chamber 20. The bromate is continuously monitored and detected and the information is transmitted to the control computer 22. The control computer 22 continuously records the bromate generation information and controls the NH ₄ Cl / H ₂ SO ₄ injection pumps 23 and 24. The NH ₄ Cl / H ₂ SO ₄ injection pumps 23 and 24 inject a predetermined amount of NH ₄ Cl / H ₂ SO ₄ into the influent water under the control of the control computer 22. Reference numeral 25 denotes an ozone generator, and 26 denotes a pH meter.

In the bromate detection device 21, the presence of bromate in the effluent from the ozone oxidation chamber 20 may be analyzed in real time or at a desired time interval. Analyzes are usually performed at intervals of several seconds and the results are continuously input to the connected control computer 22. Is bromate is detected or determined regulation level when detectable above (e.g. 10ppb) controls the instant NH ₄ Cl / H ₂ SO ₄ pumps (23, 24) In the NH ₄ Cl / H ₂ SO ₄ to the influent . The control computer 22 also controls the metering pump (not shown) to inject as much NH ₄ Cl / H ₂ SO ₄ as desired.

Hereinafter, the operation of the ozone oxidation treatment system will be described in more detail.

1) The bromate concentration of the effluent of the ozonation treatment chamber 20 in the bromate detection apparatus 21 is continuously analyzed at a designated time interval.

2) The bromate detection device 21 is controlled by the control computer 22 to continuously store information on the analyzed bromate concentration in the control computer 22.

3) If the detected bromate concentration exceeds the regulated concentration, it automatically enters the bromate production inhibition phase with a warning signal. The amount of NH ₄ Cl / H ₂ SO ₄ for inhibiting bromate production is derived as in Equation 1 below.

NH ₄ Cl amount = f (factor a × bromate production amount, factor b × ozone, factor c × pH)

H ₂ SO ₄ content = pH to maximize HOBr production (maintain H ₂ SO ₄ concentration to maintain pH 6.5-7)

4) The control computer 22 controls the NH ₄ Cl injection pump 23 according to the NH ₄ Cl amount calculated from Equation 1 to be injected into the inflow water in proportion to the treated water amount. In addition, the ozone generator 25 can be controlled to inject the ozone injection amount below the ozone demand amount to the extent that the bromate detection falls to a stable value. Then, the H ₂ SO ₄ injection pump 24 is controlled to maintain the pH (pH 6.5-7) at the desired level while continuously measuring the effluent with the pH meter 26.

5) When NH ₄ Cl consumption decreases, ozone dose is increased step by step again.

6) Continue to perform the above steps.

Hereinafter, the bromate production suppression mechanism will be described.

First, bromide ions in water react with ozone to primarily form hypobromite ions (OBr ⁻ ), which in turn react with 2 moles of ozone to produce bromate. Thus, in addition to the reaction with ozone, bromide may have a reaction with OH radicals.

Important factors in bromate production include pH, ammonia concentration (NH ₄ Cl produces ammonia in water), organic concentration, etc. This is the primary product of hypobromite ion (OBr ⁻⁾ during ozonation of bromide. ) Continue to react with ozone to produce protons to form HOBr, which can be converted to NH ₂ Br or organobromine compounds.

Therefore, in general surface water, the degree of inhibition of bromate production varies according to ammonia concentration and DOC (Dissolved Organic Carbon) concentration. Therefore, if applied, continuous bromate generation of bromate is generated during continuous monitoring of bromate production. In this case, bromine production can be suppressed by adding NH ₄ Cl or other harmless organic substances. In addition, bromate production can be suppressed by adjusting the pH or reducing the amount of injected ozone.

Figure 3 is a graph showing the results of the bromate production inhibitory test according to the ammonia concentration, in the case of injecting ammonia solution into the influent in the ozone oxidation treatment system 0ppm, 1ppm, 2ppm, 3ppm respectively Concentrations (ppb) are shown in bar graphs. As shown, when the ammonia solution is injected as compared with the case where no ammonia solution is injected, the degree of inhibition of the production of bromate is very excellent.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

For example, in the above-described embodiment, the ozone oxidation treatment system has been described as an example, but the present invention can be applied to other oxidation treatment systems such as a chlorine oxidation treatment system capable of producing bromate.

The present invention described above enables the micro analysis of the toxic byproduct bromate generated in the oxidation treatment process, which is a unit process of the water treatment facility, so that the concentration can be efficiently controlled below the regulated concentration, and the structure of the system is simple. It is easy to maintain and repair. In addition, the present invention can be expected to accelerate the development of oxidation, particularly ozone oxidation-related technology development.

Claims (10)

Selective inlet means for selectively introducing chloropromazine / hydrochloric acid mixed reagent and sample water into the mixing means; The mixing means for mixing the mixing reagent and the distilled or sample water; Absorbance analysis means for detecting bromate in the mixed solution provided through the mixing means; And Control means for controlling the selective inflow means Bromate detection device comprising a. The method of claim 1, wherein the selective inlet means, A sample automatic injection loop for selectively providing said sample number to said mixing means; And a capacity variable chemical pump for providing the mixing reagent to the mixing means and for supplying the distilled water or sample water to the sample injection loop. The method according to claim 1 or 2, wherein the mixing means, Bromate detection device comprising a Teflon reaction coil. The method according to claim 1 or 2, wherein the absorbance analysis means, A bromate detection device comprising a visible light spectrophotometer detector. The method of claim 2, wherein the sample automatic injection loop, And supplying the sample water to the mixing means at predetermined time intervals by providing the distilled water to the mixing means and being controlled by the control means. A chamber for oxidizing the influent; Selective inlet means for selectively introducing the chloropromazine / hydrochloric acid mixed reagent and the sample water discharged from the chamber into the mixing means; The mixing means for mixing the mixing reagent and the sample water; Absorbance analysis means for detecting bromate in the mixed solution introduced from the mixing means; Control means for controlling said selective inlet means; And Bromate production inhibitory means for providing a bromate production inhibitor to the influent in response to the control means Water treatment system comprising a. The method of claim 6, wherein the bromate production inhibitory means, A water treatment system comprising an ammonia injection pump. The method of claim 6, wherein the bromate production inhibitory means, Water treatment system, characterized in that the sulfuric acid injection pump. The method of claim 8, And a pH meter for measuring the acidity (pH) of said sample water and providing it to said control means. The method according to any one of claims 6 to 9, Wherein said chamber is an ozone oxidation treatment chamber, and said control means controls an ozone injection amount by controlling an ozone generator connected to said chamber.