KR100927847B1 - A total organic carbon analyzer - Google Patents

Abstract

PURPOSE: A total organic carbon analyzer is provided to prevent clogging of a device by not causing crystals from a reaction solution mixed with sodium persulfate and phosphoric acid, and to prevent errors by removing moisture. CONSTITUTION: A total organic carbon analyzer(100) comprises: a water sample supply unit(10) which supplies a water sample to a stirrer(41) through a sample tube(12) connected to a sample pump(11); a gas supply unit(20) which supplies acidification carrier gas and oxygen carrier gas; a reagent supply unit(30) which supplies a reagent to a stirrer through a reagent tube(32); an acidification reaction unit(40) for converting inorganic carbon in the water sample by reacting with phosphoric acid; a reaction unit(50) for converting organic carbon into carbon dioxide gas; a cooling unit(60) for removing moisture contained within carbon dioxide gas supplied by the oxygen carrier gas; a concentration measuring unit(70); and a display unit(80) for displaying the total organic carbon(TOC) value of the water sample.

Description

A total organic carbon analyzer

The present invention relates to a total organic carbon analyzer, in particular, consisting of a wet oxidation circuit and a carbon dioxide gas meter, the structure is simple, since the mixed reaction solution of sodium persulfate and phosphoric acid does not cause crystals, damage due to blockage of the device is prevented, It removes moisture and does not cause errors in measurement, and it is possible to measure the total amount of organic carbon contained in various measurement water such as highly contaminated water or surface water and process water. Relates to a total organic carbon analyzer.

Common total organic carbon (TOC) measurement methods proposed by the American Water Association's AWWA Standard method are the combustion-infrared method and the sulfate-ultraviolet oxidation method. ), Wet-oxidation method.

The combustion-infrared method is a method of oxidizing an organic carbon to carbon dioxide and water by oxidizing a sample to be measured at a high temperature of about 900 ° C. using an oxidation catalyst such as cobalt oxide. At this time, the generated carbon dioxide is quantified using an infrared analyzer. This method requires a high temperature and an infrared analyzer, so the apparatus is expensive.

The persulfate-ultraviolet method is a method of oxidizing organic carbon by adding persulfate to a measurement sample and irradiating ultraviolet rays. As with the combustion-infrared method, it is quantified by an infrared analyzer.

In the wet oxidation method, the sample is first acidified to release inorganic carbon into the atmosphere, and then, using persulfate as a catalyst, carbon dioxide generated when heated to 116 to 130 ° C. is quantified by an infrared analyzer.

All three methods use an infrared analyzer and have a complex disadvantage in that the analysis device is used (US Patent 5,413,763, US Patent 5,567,388, US Patent 5,820,823).

In order to solve the above problems, the oxidation of organic carbon uses wet oxidation and absorbs the generated carbon dioxide into alkaline solution, and then changes the hydrogen ion concentration of alkaline solution by measuring the absorbance using a spectrophotometer in the visible range. The method of quantifying is easily conceivable.

US Patent No. 6,368,870 makes it easy to measure based on this method. Organic carbon is oxidized using persulfate and heated to absorb carbon dioxide in alkaline solution and quantify the amount of carbon dioxide absorbed by the change in pH. In the method of using, there are external disease and internal disease as a measuring method, so that the internal disease is contained in the foreign disease.

The outer bottle has an acidic substance and the inner bottle has an alkaline solution.

The test sequence is as follows.

First, the buffer solution is added to the sample to be measured and the hydrogen ion concentration is adjusted to 2 to remove inorganic carbon.

Put the inner bottle containing the alkaline solution into the outer bottle and close the lid.

When heated at 100 ~ 150 ℃, the carbon dioxide generated from the solution of the outer bottle is collected in the alkali solution of the inner bottle and the color is changed by the indicator phenolphthalein.

With the inner bottle in the outer bottle, the absorbance is analyzed and quantified using a spectrophotometer.

However, if the total organic carbon is measured by this method, when measuring the absorbance with a spectrophotometer, the path of the light is from the light source to the outer bottle → the acid solution contained in the outer bottle → the inner bottle → the alkali solution in the inner bottle (the part to be measured) → the inner bottle. It is detected at the detector by the path of glass → acid solution contained in foreign bottles → foreign glass.

In this method, since the light from the light source of the spectrophotometer reaches the detector through various paths, the variation in absorbance is large and the absorbance value itself is low. In addition, since it is difficult for the inner disease to always stand at a constant angle in the outer disease, this may also cause measurement errors.

The conventional total organic carbon measuring device has a problem that it is impossible to measure by overconcentration when the seawater or salinity is out of the measurement range, and there is a functionally limited problem in that only the total organic carbon can be measured.

Conventional total organic carbon meter has a problem that the water sample to measure the total amount of organic carbon can be measured singly, the versatility of the measurement is deteriorated, sediment is generated in the process of converting inorganic carbon to carbon dioxide, clogging the pipe There is a problem that the equipment is damaged.

Therefore, it is possible to filter the samples of seawater or salt water of excessive concentration outside the measurement range so that the measurement range is not limited.The total organic carbon, chemical oxygen demand (COD) and biological oxygen demand (BOD) are converted into corresponding values. An improved total organic carbon analyzer capable of measuring multiple water samples simultaneously and selectively supplying and measuring them. No deposits are generated when inorganic carbon is converted to carbon dioxide. There is an urgent need.

Accordingly, the present invention has been made in view of the problems of the prior art as described above, which consists of a wet oxidation circuit and a carbon dioxide gas meter, which is simple in structure, and does not cause crystals, thereby preventing damage due to blockage of the device and removing moisture. The purpose is to provide a total organic carbon analyzer that can measure the amount of organic carbon contained in various measurement water without being limited by the degree of contamination of water samples.

In addition, another object of the present invention is to connect a plurality of different water samples to the water sample supply unit at the same time and to be selectively supplied to measure.

Another object of the present invention is to manufacture a tube in contact with a reagent made of fluorine material to increase the chemical resistance and corrosion resistance, to adjust the carrier gas with a flow valve so that a constant supply amount is supplied, the inorganic carbon contained in the water sample It is to convert carbon dioxide gas to subtract inorganic carbon from total carbon so that the total amount of organic carbon can be easily measured.

Another object of the present invention is to prepare a material of the reactor borosilicate glass material so that the transmittance of the UV light source is not lowered and is not affected by high heat, carbon dioxide gas is converted to the persulfate oxidation by using a cooler This is to minimize the moisture in the carbon dioxide gas causing the measurement error.

Another object of the present invention is to easily calculate the corresponding chemical oxygen demand (COD), biological oxygen demand (BOD) by measuring the total organic carbon, and by separating and draining and cooling the water in the carbon dioxide gas, sodium persulfate and phosphoric acid The reaction mixture is to prevent the formation of crystals.

In order to achieve the above object, the present invention provides a water sample supply unit for supplying a water sample to be measured, a gas supply unit for supplying an acidic and oxygen carrier gas for flowing carbon dioxide gas, a reagent supply unit for supplying a reaction reagent, a water sample, and a reaction reagent. , An acidification reaction part for acidifying a mixture of carrier gas, a reaction part for reacting carbon dioxide converted from inorganic carbon to acidic reaction to convert organic carbon into carbon dioxide gas by persulfate oxidation, and water in carbon dioxide gas To provide a total organic carbon analyzer comprising a cooling unit, a concentration measuring unit for measuring the carbon dioxide concentration in the carbon dioxide gas, a display unit for outputting the measured value.

In the present invention, the structure of the wet oxidation circuit and the carbon dioxide gas meter is simple and does not cause crystals, thereby preventing damage due to clogging of the device, removing water, and causing no error in measurement, and are not limited to the degree of contamination of the water sample. There is an effect that can measure the amount of organic carbon contained in the various measurement water without.

In addition, by connecting a plurality of different water samples at the same time to the water sample supply unit and selectively supplied to measure the water, the tube is made of fluorine material to increase the chemical resistance and corrosion resistance, the carrier gas is controlled by the flow valve There is an effect to supply a constant supply amount.

In addition, by converting the inorganic carbon contained in the water sample to carbon dioxide gas, it is possible to measure the total organic carbon easily by subtracting the inorganic carbon from the total carbon, and the material of the reactor is made of borosilicate glass material to transmit the UV light source There is an effect of minimizing the moisture in the carbon dioxide gas causing the error in the measurement by cooling the carbon dioxide gas is converted to the persulfate oxidation by using a cooler so as not to be affected by the high temperature without being degraded.

By measuring total organic carbon, the corresponding chemical oxygen demand (COD) and biological oxygen demand (BOD) can be easily calculated, and the mixed reaction solution of sodium persulfate and phosphoric acid is crystallized by separating and draining and cooling water in carbon dioxide gas. Has the effect of preventing the generation of

Preferred embodiments of the total organic carbon analyzer according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing a total organic carbon analyzer according to the present invention.

As shown therein, the total organic carbon analyzer of the present invention includes: a water sample supply unit 10 for supplying a water sample for measuring the total amount of organic carbon contained in the water sample to be measured; A gas supply unit 20 supplying an acidified carrier gas for flowing carbon dioxide gas and an oxygen carrier gas; A reagent supply unit 30 for supplying a reaction reagent; An acidification reaction part 40 for stirring and acidifying the mixed solution (water sample, reaction reagent, carrier gas) supplied through each of the supply parts 10, 20, and 30; A reaction unit 50 for reacting the carbon dioxide converted from the inorganic carbon to the acidification reaction so as to convert the organic carbon into carbon dioxide by oxidizing the persulfate into UV light; Cooling unit 60 for separating the water in the carbon dioxide gas; A concentration measuring unit 70 for measuring the carbon dioxide concentration in the carbon dioxide gas; The analyzer 100 is configured as a display unit 80 that outputs the measured value.

The water sample supply unit 10 is provided with a sample tube 12 having a sample pump 11 so as to supply a water sample to be measured to the stirrer 41, and the sample tube 12 has a flow sensor 12a and a water sample. A standard solution valve 13 for calibrating and replenishing a water sample supplied from the supply unit 10 and a water sample discharge valve 14 for discharging the water sample to the outside are provided.

In addition, the sample tube 12 of the water sample supply unit 10 further includes a solenoid valve branch valve 15 to selectively supply and control a plurality of water samples, as shown in FIG. In many cases, the solenoid valve branch valve 15 is to control them.

The gas supply unit 20 is provided with a gas pipe 20a provided with flow rate sensors 21 and 22 to supply the acidified carrier gas and the oxygen carrier gas to the stirrer 41, and the gas pipe 21a is provided with an acidified carrier gas. Throttle valve 20b and check valves 23 and 24 for controlling the flow of the oxygen carrier gas are provided, and the gas pipe 20a is partially branched from the gas pipe 20a and connected to the reactor 52 of the reaction part 50. The solenoid valve 25 for controlling the flow of the acidified carrier gas is provided.

Reagent supply unit 30 is provided with a reagent tube 32 is provided with a reagent pump 31 to supply the reaction reagent to the stirrer 41, between the reagent pump 31 and the stirrer 41 (flow sensor ( 32a) is installed.

The sample tube 12 and the reagent tube 32 are made of synthetic rubber containing fluorine atoms, that is, excellent in elasticity and resistant to heat, oil, and chemical corrosion, and thus made of fluorine rubber used as aerospace material and packing material. , The temperature of the reaction sample provided from the reagent supply unit 30 is to maintain 2 ~ 70 ℃.

Since the sample pump 11 and the reagent pump 31 should not idle, the water sample and the reaction reagent are injected into the sample tube 12 and the reagent tube 32 before starting or after the preparation work is completed. To extend the shelf life.

The acidification reaction unit 40 includes an agitator 41 for uniformly mixing the water sample, the acidification carrier gas, and the reaction reagents supplied through the water sample supply unit 10, the gas supply unit 20, and the reagent supply unit 30, respectively. And an acidification reactor 42 which is formed in a coil shape and in which an inorganic carbon in the water sample reacts with phosphoric acid to be converted into carbon dioxide gas during the acidification reaction of the mixture sample stirred by the stirrer 41.

The reaction unit 50 is the carbon dioxide gas in which the inorganic carbon is converted to reaction in the acidification reaction unit 40 is separated into gas / liquid and disposed of, waste water treatment at the same time irradiated with UV rays to the organic carbon in the water sample during gas / liquid separation A gas / liquid separator 51 and a reactor 52 for reacting the persulfate of the reaction reagent to convert the organic carbon into carbon dioxide gas by the persulfate oxidation are provided integrally.

The gas / liquid separator 51 is for removing the inorganic carbon from the carbon dioxide gas generated in the acidification reaction unit 40, the separated carbon dioxide gas is exhausted through the waste gas pipe (51a), the separated water is a check valve And partially drained through the wastewater pipe 51b by the 51b 'and the wastewater pump 51b ".

The reactor 52 converts organic carbon into carbon dioxide gas through persulfate oxidation upon irradiation with organic light in the water sample from which inorganic carbon has been removed, the oxidant in the reaction reagent and residual phosphoric acid through a gas / liquid separator 51, and UV light. A UV lamp tube 52b is installed inside the reactor body 52a so that the drain pipe 52c for discharging the wastewater collected during the reaction to the wastewater pipe 51b and an inlet pipe for introducing an oxygen carrier gas ( 52d) is formed, and the carbon dioxide that is overlaid on the opposite side of the reactor body 52a integrally formed with the gas / liquid separator 51 communicates with the gas exhaust pipe 52e for discharging through the waste gas pipe 51a. A water drain pipe 52f for discharging the waste water pipe 51b is provided.

The UV lamp is inserted into the UV lamp tube 52b of the reactor so that the oxidant and the water sample of the reactor 52 can be irradiated with ultraviolet rays. The reactor 52 is a UV lamp when the reagent and the water sample are not injected. Do not turn on the power.

The gas / liquid separator 51 and the reactor 52 of the reaction part 50 are made of a borosilicate glass material heat-treated, so that the transmittance does not decrease when irradiated with UV light and is not affected by high heat.

The cooling unit 60 primarily cools the heat of the carbon dioxide gas supplied from the reaction unit 50 so as to aggregate and remove water contained in the carbon dioxide gas flowing and supplied by the oxygen carrier gas moved to the reaction unit 50. And a cooler 62 which aggregates moisture while maintaining the cooling temperature of the carbon dioxide gas passing through the cooling pipe 61 within 2 to 7 ° C. This is because the cooling temperature is an optimal temperature at which moisture contained in the atomized state in the carbon dioxide gas can aggregate.

The cooler 62 must remove moisture before the carbon dioxide gas enters the non-dispersion infrared carbon dioxide gas detector (NDIR) because moisture (steam) interferes with the non-dispersion infrared carbon dioxide gas detector (NDIR), It can be composed of any one of an electronic cooler, a hunting water roller, an air breasted coil cooler, and a permission tube, which can be selectively configured according to the type of sample to be measured and the manufacturing cost of the device.

The concentration measuring unit 70 filters the solid granules in the carbon dioxide gas from which water is removed through the cooling unit 60, and then is moved to a non-dispersion infrared carbon dioxide gas detector NDIR or a conduction cell carbon dioxide gas detector carbon dioxide. The concentration of the gas is measured. In the present invention, a method of measuring using a non-dispersive infrared carbon dioxide gas detector (NDIR) will be described as an example.

As shown in FIGS. 1 and 4, the infrared carbon dioxide gas detector NDIR constituting the concentration measuring unit 70 includes an actuator 71 and an infrared lamp 72, and the actuator 71 is an infrared carbon dioxide. It is a high-pressure generator that controls the voltage of the gas meter, so the primary voltage can reach 220V and the secondary voltage can reach 3000V, so be careful of high-voltage accidents and do not touch exposed parts of the relevant contacts during work.

The infrared lamp 72 is made of a quartz glass material with good transmittance, which is controlled by the actuator 71 and whose wavelength is not reduced to emit infrared light, and is scaled on the outer wall of the infrared lamp 72 to maximize oxidation efficiency. When scaling occurs, it is cleaned according to the nature of the scale to maintain the oxidation efficiency.

Concentration measuring unit 70 is chlorine (Cl ^-), sulfate (SO4 ^{2 -) -,} phosphate (HPO4 ^{2 -),} phosphoric acid solution (PO4 ^{3 -),} nitrogen (NO3), or the concentration is 400mg / l or more of sulfur ( S ^{2 -),} such as a concentration of 100mg / or more ion traps (IRON tRAP) filter (73 to absorb so that they can be measured or the sea water with high salt content of the waste water) that can be configured are further included. At this time, the ion trap filter 73 is coupled to the calibration button 73a for calibration.

The display unit 80 outputs an analog signal corresponding to the carbon dioxide gas concentration measurement value of the concentration measuring unit 70, amplifies, converts the analog signal into a digital signal, and calculates the total organic carbon (TOC) value of the water sample. It consists of an intermediate amplifier 81, an analog / digital converter 82, a data processor 83, and an output 84 for display.

The intermediate amplifier 81 amplifies the concentration measurement value of the carbon dioxide gas in the concentration measuring unit 70, the analog / digital converter 82 is to convert the analog signal passed through the intermediate amplifier 81 to digital, the data processor Reference numeral 83 calculates the concentration of the total organic carbon in the water sample by calculating and processing the analog concentration measurement value through the analog / digital converter 82 to generate a standard calibration graph.

A data processor 83 and external components such as a keyboard, power panel, and main board, which are not shown in the drawing, are provided. The keyboard has numeric keys and function keys for inputting data and selecting functions. Make sure

The output unit 84 is a device for outputting the measured value processed by the data processor 83 using the monitor 84a or the printer 84b.

The display unit 80 is configured to measure the total organic carbon (TOC) in the water sample and calculate and output a corresponding chemical oxygen demand (COD) and biological oxygen demand (BOD) by the data processor 83, and the display unit 80 is configured to display the measured value of total organic carbon or organic carbon through the output unit 84 at average concentrations per minute, hourly, daily, and monthly.

The analyzer 100 includes an operation controller and an intelligent alarm not shown in the drawing. The operation controller is a non-dispersible infrared carbon dioxide gas measuring instrument of the concentration measuring unit 70 at 80 degrees Celsius, which is a proper operating temperature of the reactor 52. (NDIR) or battery also automatically protects various functions by controlling the temperature conditions so that the constant temperature environment of 2 ~ 7 ℃ is maintained in the cooler 62 of the cooling unit 60, which is 40 degrees Celsius, which is the optimum temperature of the carbon dioxide meter. The intelligent alarm is composed of sensor, single chip and external components, and the alarm will sound when reaction reagent, water sample does not flow into the semi-functional 52, or when acidity and oxygen carrier gas flow abnormally. It is to be operated again when it stops and returns to normal state.

Referring to the operation of the total organic carbon analyzer of the present invention configured as described above are as follows.

As shown in FIG. 1, in order to use the analyzer 100 for the measurement, a pure water (water sample) prepared in advance, a standard solution of 1000 mg / Lc, a phosphoric acid / sodium persulfate reagent / washing agent were prepared, and the concentration was measured by a test operation. After the calibration operation through the calibration of the unit 70, zero (ZERO) gas, standard gas calibration is used for measurement, briefly look at the test operation process for calibration.

A standard solution of 1000 mg / L.c was treated with anhydrous potassium hydrogen phthalate, and placed in a weighing bottle and dried in a desiccator for 2 hours at 118 ° C., and then cooled in a desiccator. Accurately measure 2.125 g of dried potassium phthalate (KHP), melt in a 1000 ml volumetric flask, and dilute to scale.

Then, open the shut-off valve of the air supply device (not shown) to adjust the pressure to 0.2 mpa so that the flow rate of the acidified carrier gas reaches 20 ml / min, and the flow rate of the oxygen carrier gas is 160-220 ml /. min or 100-120 ml / min. At this time, connect the earth leakage protection breaker of the operation controller and the main power switch and check the monitor screen.

Meanwhile, distilled water is taken with a 20 ml syringe, and the distilled water is injected into the sample pump 11 and the sample tube 12 through the standard solution valve 13 of the water sample supply unit 10 so that the sample pump 11 does not idle. Then, the phosphoric acid and sodium persulfate solution is taken with another syringe, and reagents are injected into the reagent pump 31 and the reagent tube 32 of the reagent supply unit 30 to prevent idling of the reagent pump 31.

Then, the operation controller is operated to drive the sample pump 11 and the reagent pump 31 to move the distilled water and the reaction reagent to replace the water sample to the reaction unit 50, respectively. After fully injecting a mixture of distilled water and reaction reagent mixed into the reactor 52 of the reaction unit 50, turn on the UV light source power switch.

The non-dispersion type infrared carbon dioxide gas detector (NDIR) of the concentration measuring unit 70 is calibrated. Loosen the sealing nut (not shown) of the concentration measuring unit 70 and inject high purity nitrogen or oxygen zero gas into the 'standard gas supply part G, and then adjust the zero gas potentiometer (not shown). Confirm that the value '0' appears on the display 80.

After injecting carbon dioxide standard gas of 400, 1000, or 2000 ppm into the concentration measuring unit 70, the process of adjusting the standard gas potentiometer to bring the value shown on the monitor as close as possible to the standard gas concentration value is 2 to 3 times. After repeating, test preparation and calibration are completed.

In order to measure the total amount of organic carbon in the water sample using the calibrated analyzer 100 as described above, the total organic carbon amount (TOC) = total carbon (TC) -inorganic carbon (IC) can be measured simply and quickly using a basic equation. can do.

After the test operation procedure is sequentially performed on the analyzer 100, power is supplied, and preparation of water sample preparation, preparation of acidic carrier gas and oxygen carrier gas, and preparation of reaction reagent are performed. In this case, the water sample supply unit 10 connects a plurality of types of water samples using a single type of water sample or a solenoid branch valve 15, and then selectively supplies only the water samples required for the measurement. In many cases, no replacement is required, which shortens the preparation and time for measurement.

Thereafter, when the sample pump 11 of the water sample supply unit 10 and the reagent pump 31 of the reagent supply unit 30 are operated, the water sample and the reaction reagent flow along the sample tube 12 and the reagent tube 32. The acidified carrier gas of the gas supply unit 20 flows into the gas pipe 20a in a state in which the supply amount is controlled and the backflow is prevented through the flow sensor 21 and the check valve 23 so that the stirrer of the acidification reaction unit 40 is prevented. 41, the solenoid valve 25 is kept closed to prevent the inflow of acidified carrier gas into the reaction unit 50.

Since the sample tube 12 and the reagent tube 32 are made of a fluorine rubber material, they can flexibly respond to shaking due to flow, and have excellent chemical resistance and thus have long durability. At this time, the flow rate to be supplied is supplied to the stirrer 41 in the order of water sample, reaction reagent, acidified carrier gas in order of rapidity.

The water sample supplied to the stirrer 41, the reaction reagent, and the acidified carrier gas are mixed to form a mixture sample. The inorganic carbon in the water sample reacts with phosphoric acid while flowing into the acidification reactor 42 and undergoing an acidification reaction process. Converted to gas. At this time, looking at the process of converting inorganic carbon into carbon dioxide gas;

-Before measuring the total amount of organic carbon, carbonates, bicarbonates and carbon dioxide in dissolved state must be removed. The purpose is to find out the amount of organic carbon. After mixing the water sample and the reaction reagent, the inorganic carbon and phosphoric acid react therein.

M _e CO ₃ + H ₃ PO ₄ -----> M _e HP ₄ + CO ₂ + H ₂ O, M _e HCO ₃ + H ₃ PO ₄ -----> M _e H ₂ PO ₄ + CO ₂ + H ₂ O

When the inorganic carbon reacts with phosphoric acid and is converted into carbon dioxide gas, it is supplied to the gas / liquid separator 51 of the reaction unit 50 by the acidified carrier gas, and carbon dioxide gas and water, which are pure gas states contained in the carbon dioxide gas, The gaseous carbon dioxide gas is separated and discharged to the outside of the analyzer 100 through the waste gas pipe 51a and some moisture through the waste water pipe 51b.

While the acidic carrier gas of the gas supply unit 20 is blocked while the inorganic carbon is removed, the oxygen carrier gas sequentially moves the flow sensor 22, the check valve 24, and the open solenoid valve 25. It passes through the bottom of the reactor 52 of the reaction unit 50 while passing through.

At this time, the water sample and the reaction reagent are mixed, enters the reactor 52 and irradiates with UV rays to rapidly react the oxidizing agent sodium persulfate (ammonium) with the organic carbon in the reaction sample to form carbon dioxide gas. Looking at the reaction to convert to;

CO ₂ H ₂ O + λ ----> H

H + H -----> H ₂

Organism + ₂ H ₂ O ----> 1 / 2CO ₂ + H ₂ O

Organic Carbon + S ₂ O = 8 + H ₂ O ----> (UV Rays) H ₂ SO ₄ + SO = 4 + 1 / 2CO ₂

That is, the organic carbon is converted into carbon dioxide gas by persulfate oxidation of the persulfate of the organic carbon and the reaction reagent in the water sample when irradiated with UV light.

In this way, the carbon dioxide gas in which the organic carbon is converted is flowed to the cooling unit 60 through the upper portion of the reactor 52 of the reaction unit 50 by the oxygen carrier gas.

The carbon dioxide gas condenses moisture present in the carbon dioxide gas while passing through the cooler 62 of the cooling unit 60 at a temperature of 2 ° C. to 7 ° C., and is treated with wastewater through the wastewater pipe 51b.

On the other hand, the carbon dioxide gas from which water is removed while passing through the cooling unit 60 is supplied to the concentration measuring unit 70, and the concentration of carbon dioxide in the carbon dioxide gas by the non-dispersive infrared carbon dioxide gas detector NDIR or the conduction cell carbon dioxide gas meter. Can be saved.

As shown in FIG. 4 and FIG. 5, first, a method of obtaining the concentration of carbon dioxide by using the non-dispersion infrared carbon dioxide gas detector NDIR will be described.

1) Analysis principle: The carbon dioxide gas is based on the selective absorption of infrared rays, the absorption intensity is determined by the concentration of carbon dioxide gas, and the change in the concentration of carbon dioxide gas is measured by the contrast of infrared rays before and after the measurement. Details are as follows.

-The reason for analyzing gas using infrared rays is as follows.

(1) Every gas has its own specific absorption spectrum for infrared light.

Almost all gases (including water vapor), with the exception of monatomic and homonuclear diatomic gases, have a selective absorption of infrared radiation. Different gases have specific absorption spectra different for infrared. For example, carbon dioxide is near 4.26 µm, carbon monoxide is near 4.65 µm and methane is near 3.35 µm.

(2) Infrared thermal reaction is the strongest of all light beams.

Infrared light absorbs a significant portion of the energy of a corresponding frequency band after passing through a gas. That is, quantitative analysis of the gas to be measured may be performed through energy changes of infrared rays before and after measured using a measuring instrument that is very sensitive to thermal reaction.

(3) The structure of the measuring instrument uses a double optical path thin film capacitance meter, and the two optical path spectra of the working reference are the same and the energy is the same. If the infrared spectrum emitted from the control light source is divided into four parts A, B, C, and D, A is the specific absorption spectrum corresponding to the gas to be measured, and B and C are the background interference gas to the process to be measured. The absorption spectrum, D, has other spectral components of 0.76 to 12 µm.

Thus, after the infrared rays of the working light path pass through the working gas chamber, A, B, and C are partially consumed. The B, C, and D spectra cannot all enter the instrument because this infrared light passes through the OPTICAL FILTER again and can only pass the A spectrum.

In addition, after the infrared ray of the reference optical path passes through the (OPTICAL FILTER), all of the B + C + D spectrum is also blocked, but A has no loss. The two chambers of the instrument contain A gas, which is sensitive only to the A spectrum, so the energy (A spectrum) obtained from the two chambers is different. The thermal reaction and gas expansion caused by these two reception rooms are also different. The expansion pressure acting on the thin film capacitance copper pole also floats, causing a change in the distance between the copper pole and the positive electrode and causing a change in the amount of capacitance.

On the other hand, according to the control of the light cutting piece, the thin film capacitance has a periodic change which is the same as the light cutting frequency, and the change range is the energy of A (that is, the specific absorption spectrum of the gas to be measured). It is related to change.

2) The measurement principle of NDIR is as follows.

First, there is a DC polarization voltage at the anode of the thin film capacitance, and the capacitance is continuously charged in accordance with the change of capacitance, and the prepole receives a voltage signal that is changed from both sides of the resistor RＷ. The signal can be sent to the main amplifier to magnify the signal and then subjected to proper processing to complete the gas-thermal-electrical conversion to accurately measure the change in energy (gas to be measured).

The correspondence between the change in A energy and the change in A gas concentration can be explained by Bill's Law.

I = IO e-K. C.L

(In formula: IO-initial energy of light before passing through the gas to be measured, I-residual energy of light after passing through the gas to be measured, K-absorption coefficient of the gas to be measured, C-volume percentage concentration of the gas to be measured, L -The thickness of the gas to be measured (with the length of the working gas chamber of the instrument).

In addition, since IO, K, and L are all quantitative and only C is variable in a measuring instrument, when a infrared ray measures the change of the energy after passing through the measurement object gas, the concentration change of the measurement object gas can be measured.

In addition, there are two types of sensors for measuring the change in energy: semiconductor and cosmetic. Currently, the semiconductor infrared carbon dioxide meter is slightly less sensitive than cosmetics, and is mainly used in places where the TOC content is relatively high, such as petrochemical companies and wastewater treatment plants.

As shown in Figure 6 and Figure 7, Next, let's find a way to obtain the concentration of carbon dioxide using the conduction cell carbon dioxide gas meter.

1) Measurement process: When the acidified carrier gas passes through the stirrer 41, it carries a quantity of conductive liquid and enters the coil pipe of the gas / liquid reactor 51 to proceed with sufficient chemical reaction. If a small amount of carbon dioxide is contained in the acidified carrier gas supplied from the gas supply unit 20 causes the following reaction.

^{_{CO 2 + 2OH - ----> CO}} = 3 + H 2 O

The acidified carrier gas after the reaction exits the gas / liquid separator 51, and the conducting liquid after the reaction measures the conductivity at the <measuring electrode>.

If carbonic acid gas is contained in the acidified carrier gas, after the reaction, the conduction liquid enters the <negative ion exchange resin> and thus the reaction occurs as follows. Therefore, the ion concentration of the conduction liquid is always kept constant. Passed conduction liquid is measured for conductivity at <reference electrode>.

_{^{2R-OH + C0 = 3 ----}} > R 2 CO 3 + 2OH -

2) The working principle of the conduction cell carbon dioxide meter is as follows.

The electrolyte solutions all have conduction capacities, but the former belongs to electron conduction and the latter is based on the transition of ions, so the conduction principle of both is completely different. When evaluating the conductivity of a solution, it is usually expressed as conductivity (L) and the relation is as follows.

L = 1 / R = K / Q = λ.C / 1000Q

(Conductivity in L-electrolyte solution (unit: Ω), R-resistance, conductivity of K-electrolyte solution (determined by solution type, concentration, and temperature), Q-conductor constant (determined by geometric dimensions of the electrolytic cell) ), Λ-electrolyte equivalent conductivity, and C-electrolyte equivalent concentration.

The conductivity of the electrolyte solution is only related to the equivalent conductivity of ions when the geometry of the conduction cell is fixed, the composition and concentration of the electrolyte is also fixed (0.001N NaOH), and the temperature environment of the two pairs of conduction cells is relatively always warm. And the total amount of equivalent conductivity of ions. In other words, the conductivity is obtained by the following reaction formula.

^{L1 = C (∧Na + + ∧OH} -). / 1000Q

When a trace amount of carbon dioxide gas enters the gas / liquid reaction tube and is absorbed in OH ^_ , the conductivity is measured at X% and the conductivity is measured at <Measurement electrode>.

^{L2 = C. [∧Na + +} ∧OH - -C X X% ∧OH - + C X X% C0 = 3]

Putting these two formulas together, the conductivity of the solution changes as follows.

ΔL = L1-L2 = CC _X X% (∧OH ^-- C0 ⁼ ₃ ) / 1000Q

(△ L --- conductivity change value, L1 --- conductivity measured at the reference electrode, L2 --- conductivity measured at the measuring electrode, ∧Na ⁺ --- equivalent conductivity of sodium ions, C0 ⁼ ₃ --- Equivalent conductivity of nitrate ion, CO2 gas concentration in C _X --- reaction gas, X% --- reaction efficiency of CO2 and NaOH)

Here, the reaction rate X% is a fixed value when the flow rate of the conductive liquid, the flow rate of the gas, the temperature, and the solution equivalent concentration are all constant. Therefore, the change in conductivity is only related to the concentration of carbon dioxide, and thus the concentration of trace carbon dioxide in the reaction gas can be obtained by measuring the change in conductivity ΔL.

As such, the measured value of the amount of carbon dioxide measured by the concentration measuring unit 70 is transmitted to the display unit 80. The measured value is first amplified through the intermediate amplifier 81, and the amplified measured value converts the analog signal into a digital signal. After converting into a digital signal through an analog / digital converter 82 converting to a digital signal, the total organic carbon content (TOC) is obtained, and the chemical oxygen demand (COD) and biological oxygen demand (BOD) are calculated by using a corresponding relation. An example of the correspondence relationship is as follows.

First, it is assumed that the condition is that the ratio of the total organic carbon content (TOC) / chemical oxygen demand (COD) / biological oxygen demand (BOD) of the stabilized water sample is stabilized as a condition. In this case, the total organic carbon content (TOC) / chemical oxygen demand (COD) / biological oxygen demand (BOD) values of the water samples were measured, respectively, and the total organic carbon content (TOC) = 100 as a corresponding value of COD / BOD. The chemical oxygen demand (COD) / biological oxygen demand (BOD) is measured by simply calculating the parameters of the chemical oxygen demand (COD) / biological oxygen demand (BOD) and converting them into the data. There is an advantage that a separate device and equipment for it is unnecessary.

If the total organic carbon (TOC) actual measurement is 20, the biological oxygen demand (BOD) is 30, and the chemical oxygen demand (COD) is 10, TOC = 100/20 = 5 times, BOD = 30 × 5 = 150, COD If the total organic carbon content is measured by setting the parameter of COD to 50 and the parameter of BOD to 150 in the data processor 83, the chemical oxygen demand (COD) / biological The value of the oxygen demand (BOD) can be calculated, where a TOC = 100 value represents a default value.

In addition, the carbon dioxide gas flowing into the concentration measuring unit 70 passes through the ion trap filter 73 and the concentrations of chlorine (Cl ⁻ ) and sulfuric acid (SO 4 ^{2 −} ) are 400 mg / l or more, or nitrogen (NO 3 ⁻ ) or phosphoric acid. (HPO4 ^2- ), phosphate solution (PO4 ^3- ), sulfur (S ^2- ), etc., the concentration of 100mg / or more of the solid granules contained in seawater or high salt content wastewater can be removed to measure a variety of water samples There is an advantage that the versatility is increased without being constrained by the contamination, concentration and other conditions of the measured sample.

The display unit 80 monitors or prints the measured value and the calculated value of total organic carbon (TOC) / chemical oxygen demand (COD) / biological oxygen demand (BOD) at an average concentration per minute, hourly, daily, and monthly It is possible to record data easily and conveniently, and can be applied differently according to the measurement conditions, thereby increasing the operability.

In the above, the present invention has been illustrated and described with reference to specific preferred embodiments, but the present invention is not limited to the above-described embodiments and is not limited to the spirit of the present invention. Various changes and modifications can be made by those who have

1 is a schematic view showing a total organic carbon analyzer according to the present invention,

2 is a schematic diagram illustrating a water sample supply unit according to another embodiment;

3 is a schematic view showing a reaction unit,

4 and 5 is a schematic configuration and electrical circuit diagram of the non-dispersion infrared carbon dioxide gas detector (NDIR),

6 and 7 are schematic configuration diagrams and electrical circuit diagrams of a conduction cell carbon dioxide gas measuring device (conductivity cell).

<Description of Symbols for Main Parts of Drawings>

10: water sample supply unit 11: sample pump

12 sample tube 12a flow sensor

13: Standard solution valve 14: Water sample discharge valve

15: solenoid valve branch valve

20: gas supply unit 20a: gas pipe

20b: Throttle Valve 21: Flow Sensor

22: flow sensor 23: check valve

24: check valve 25: solenoid valve

30: reagent supply unit 31: reagent pump

32: reagent tube 32a: flow sensor

40: acidification reaction part 41: agitator

42: acidification reactor 50: reaction part

51: gas / liquid separator 51a: waste gas pipe

51b: Waste water pipe 51b ': Solenoid valve

51b ": wastewater pump 52: reactor

52a: reactor body 52b: UV lamp tube

52c: drain pipe 52d: inlet pipe

52e: gas exhaust pipe 52f: water drain pipe

60: cooling unit 61: cooler pipe

62: cooler

70: concentration measuring unit 71: actuator

72: infrared lamp 73: ion trap filter

73a: calibration button 80: display

81: intermediate amplifier 82: analog / digital converter

83: data processor 84: output unit

84a: monitor 84b: printer

100: analyzer G: standard gas supply unit

Claims (15)

In the total organic carbon analyzer for measuring the amount of organic carbon, A water sample supply unit 10 for supplying a sample of measurement water to the stirrer 41 through a sample tube 12 connected to the sample pump 11, A gas supply unit 20 for supplying an acidified carrier gas and an oxygen carrier gas, A reagent supply unit 30 for supplying a reaction reagent to the stirrer 41 through the reagent tube 32; An agitator 41 for mixing the mixture sample supplied by each supply unit is provided with an acidification reaction unit 40 for converting the inorganic carbon in the water sample with phosphoric acid to convert to carbon dioxide gas during the acidification reaction, The carbon dioxide gas reacted with the inorganic carbon in the acidification reaction part 40 is separated into gas / liquid, disposed of and disposed of in wastewater and treated with UV light. Reaction unit 50 for converting the organic carbon into carbon dioxide gas by the persulfate oxidation action, A cooling unit 60 for removing moisture contained in carbon dioxide gas flow-fed by the oxygen carrier gas supplied to the reaction unit 50; Concentration measuring unit 70 consisting of a non-dispersive infrared carbon dioxide gas meter (NDIR) or a conduction cell carbon dioxide gas meter (conductivity cell) for filtering and moving the solid granules in the carbon dioxide gas from which water is removed. Wow, The display unit 80 further outputs an analog signal corresponding to the carbon dioxide gas concentration measurement value of the concentration measuring unit 70 to display a total organic carbon (TOC) value of the water sample by amplification, analog / digital conversion, and arithmetic processing. Total organic carbon analyzer comprising a. The total organic carbon analyzer according to claim 1, wherein the sample tube (12) and the reagent tube (32) of the water sample supply unit (10) and the reagent supply unit (30) are made of a fluororubber material. The total organic carbon analyzer according to claim 1, wherein the temperature of the reaction sample is maintained in a range of 2 to 70 ° C. The total organic carbon analyzer according to claim 1, wherein the acidification reactor (42) for acidifying the mixture sample mixed in the stirrer (41) is configured in the form of a coil. The gas / liquid separator of the coil pipe shape for removing the inorganic carbon from the carbon dioxide gas generated in the acidification reaction unit 40, Reactor body for converting organic carbon into carbon dioxide gas by irradiating UV rays with organic matter in the water sample from which inorganic carbon has been removed from the gas / liquid separator (51) and oxidant and residual phosphoric acid in the reaction reagent. UV lamp tube 52b is provided inside 52a, a drain tube 52c for discharging wastewater collected during the reaction, and an inlet tube 52d for introducing oxygen carrier gas therein, and a gas / liquid separator On the opposite side of the reactor body 52a in which the 51 is integrally formed, the total organic material comprises a reactor 52 having a water drain pipe 52f communicating with a gas exhaust pipe 52e through which overflow carbon dioxide gas is exhausted. Carbon analyzer. According to claim 1, Cooling unit 60 is a cooling pipe 61 for dissipating the heat of the carbon dioxide gas gas supplied from the reaction unit 50 to the primary cooling, and the carbon dioxide passed through the cooling pipe 61 Total organic carbon analyzer, characterized in that consisting of a cooler 62 for agglomeration of moisture while maintaining a cooling temperature of the gas 2 ~ 7 ℃. According to claim 1, wherein the concentration measuring unit 70 is a non-dispersion type infrared carbon dioxide gas meter is composed of an actuator 71 for controlling the voltage, and an infrared lamp 72 for emitting infrared rays inside the actuator (71). Total organic carbon analyzer, characterized in that. The method of claim 1, wherein the concentration measuring unit 70 is chlorine (Cl ^-), sulfate (SO4 ^{2 -)} concentration of 400mg / l or more, or nitrogen (NO3 ^-), the phosphate (HPO4 ^{2 -),} phosphoric acid solution (PO4 ^{3 -),} a sulfur (S ^{2 -),} the concentration of such gun according to claim 1, further comprising an ion trap (IRON tRAP) filter 73 to absorb so that they can be measured with high 100mg / or more sea water or salt content of the waste water Organic Carbon Analyzer. The method of claim 1, wherein the display unit 80 is an intermediate amplifier 81 for amplifying the concentration measurement value of the carbon dioxide gas in the concentration measuring unit 70, and converts the analog signal passed through the intermediate amplifier 81 into a digital signal In the data processor 83 and the data processor 83 for calculating the concentration of total organic carbon in the water sample by arithmetic processing the analog concentration measurement value passed through the analog / digital converter 82 and the analog / digital converter 82. A total organic carbon analyzer comprising an output unit (84) for outputting the processed measurement value to a monitor (84a) or a printer (84b). The total organic carbon analyzer of claim 1, wherein the water sample supply unit (10) further includes a solenoid valve branch valve (15) to selectively supply a plurality of water samples. The total organic carbon analyzer according to claim 5, wherein the gas / liquid separator (51) and the reactor (52) of the reactor (50) are made of borosilicate glass material heat-processed. 7. The total organic carbon analyzer of claim 6, wherein the cooler (62) comprises one of an electric cooler, a hunting water roller, an air breasted coil cooler, and a permission tube. The method of claim 1, wherein the display unit 80 calculates and outputs a corresponding chemical oxygen demand (COD) and a biological oxygen demand (BOD) by measuring a total organic carbon (TOC) in the water sample. Total organic carbon analyzer, characterized in that configured to be. 13. The total organic carbon analyzer of claim 12, wherein the infrared lamp (72) is made of a quartz glass material whose wavelength transmittance is not reduced. The total organic carbon analyzer according to claim 13, wherein the display unit (80) displays the measured values in average concentrations per minute, hourly, daily, and monthly.

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