KR20040023169A - Composite electrode for COD measurement - Google Patents
Composite electrode for COD measurement Download PDFInfo
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- KR20040023169A KR20040023169A KR1020020054826A KR20020054826A KR20040023169A KR 20040023169 A KR20040023169 A KR 20040023169A KR 1020020054826 A KR1020020054826 A KR 1020020054826A KR 20020054826 A KR20020054826 A KR 20020054826A KR 20040023169 A KR20040023169 A KR 20040023169A
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- electrode
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- composite electrode
- cod
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/18—Water
- G01N33/1806—Biological oxygen demand [BOD] or chemical oxygen demand [COD]
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/18—Water
- G01N33/1893—Water using flow cells
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- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Immunology (AREA)
- Engineering & Computer Science (AREA)
- Pathology (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Medicinal Chemistry (AREA)
- Food Science & Technology (AREA)
- Molecular Biology (AREA)
- Biodiversity & Conservation Biology (AREA)
- Biomedical Technology (AREA)
- Emergency Medicine (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Abstract
Description
본 발명은 안정적이면서 견고하고 재현성 있는 전극을 사용하여 COD를 측정하는 방법 및 이를 이용한 유기물 농도 측정 장치에 관한 것이다. 자연, 인공 수질환경 (강, 바다, 하천수, 호수, 댐, 저수지, 늪지 등) 및 오염환경 (생활폐수, 축산폐수, 산업폐수, 폐수처리장 등)에서 중요한 화학성분들에 대한 정보를 알아내는 것은 매우 중요하다. 특히 여러가지 화학종 중에서 유기물의 농도를 측정할 수 있거나 이의 변화를 감지하는 것은 수질환경의 보호 및 오염수역의 처리를 위해서는 필수적일 뿐만 아니라 이에 대한 실시간 모니터링 기술이 시급히 요구되고 있는 실정이다. 이러한 분석 및 처리측면에서 전기화학적 기술은 이미 가장 적절한 수단으로서 광범위하게 발전되어 왔고, 특히 분석물질을 실시간으로 측정하기 위해 수반되어야 할 요소들 - 안정성, 정확성, 재현성, 신속성, 경제성 등이 보장될 수 있는 가장 확실한 방법으로서 부각되어 왔다.The present invention relates to a method for measuring COD using a stable, robust and reproducible electrode, and an organic material concentration measuring apparatus using the same. It is very difficult to find information on important chemicals in natural and artificial water environments (rivers, seas, rivers, lakes, dams, reservoirs, swamps, etc.) and in contaminated environments (living wastes, livestock wastes, industrial wastes, wastewater treatment plants, etc.). It is important. In particular, the measurement of the concentration of organic matter or the detection of changes among various chemical species is not only essential for the protection of the water environment and the treatment of polluted water, but also a situation in which real-time monitoring technology is urgently required. In terms of such analysis and processing, electrochemical techniques have already been extensively developed as the most appropriate means, and in particular, the factors that must be involved in real time measurement of analytes-stability, accuracy, reproducibility, speed, economics, etc. can be guaranteed. It has emerged as the surest way to be.
현재까지 오염 유기물질의 정량을 위해서 측정지표로 사용되는 방법에는 화학적 산소소비량 (Chemical Oxygen Demand), 생화학적 산소소비량 (Biochemical Oxygen Demand), 총유기체 탄소량 (Total Organic Carbon) 등이 있는데, 이 중에서 COD는 주로 정수장, 댐 등의 폐쇄성 수역에서 모든 유기물질을 산화시키기 위한 산소량을 구하여 생태계에 미치는 잠재적인 영향을 나타내는데 사용되어 왔다. 뿐만 아니라 현재는 생활하수, 실험폐액, 폐수처리장 방류수, 폐수 배출수 등과 같은 다양한 유기폐수와 동적수계에까지 그 영역이 확대되어 실제 BOD 나 TOC 에 비하여 그 측정값의 필요성이 증대되고 있다.To date, the methods used as measurement indicators for the quantification of contaminated organic substances include chemical oxygen demand, biochemical oxygen demand, and total organic carbon. COD has been used to determine the potential impact on ecosystems by determining the amount of oxygen used to oxidize all organic matter in closed waters, mainly in water treatment plants and dams. In addition, the area has been expanded to various organic wastewater and dynamic water systems such as domestic sewage, laboratory wastewater, wastewater treatment plant effluent, and wastewater effluent, and the necessity of the measured value is increasing compared to actual BOD or TOC.
표준 COD의 측정방법은 강한 산화제를 이용하여 유기물을 고온, 강산에서 화학적으로 산화시키는 방법으로써 과망간산칼륨(KMnO4) 및 중크롬산칼륨(K2Cr2O7)을 이용한 방법이 있다 [참조 American Public Health Association, Standard Methods for the Examination of Water and Wastewater, 17th Edition, American Public Health Association, Washington, DC, 1989, pp. 5-10]. 그러나 화학적으로 안정하게 존재하는 연쇄상 유기물질의 분해가 어려워 정확한 측정이 곤란하며 염화물이나 아질산염 등에 의해 실험오차가 커지는 문제점이 있고 분석조작상의 개인오차와 실험에 이용되는 산화제의 종류 및 농도, 온도, 가열시간, 반응조건의 변화에 의해서도 큰 영향을 받는다. 또한 고온과 강산이라는 극한조건에서 수행해야 하고 수은화합물과 황산과 같은 위험한 시약을 사용하고 있기 때문에 측정시 특별한 주의를 요하고 다루기가 위험하며 실험 이후 발생되는 폐액의 문제를 해결하지 못하고 있다. 게다가, 1회 측정시 사용되는 분석시약이 다량 소모되므로 비용면에서도 비효율적이다. 무엇보다도 이와 같은 COD 측정방법은 30분~1시간 정도의 측정 시간을 필요로 하는데, 이는 변동하고 있는 수계에서의 유기 물질의 농도를 실시간 모니터링 하는데 적합치 못한 단점이 있다. 이를 위한 COD의 연속측정 및 표준화가 시급히 요구되지만, 배출수량의 자동측정은 가능하나 실제 COD값의 정확한 측정을 위해서는 시간이 많이 소요되므로 일정한 시간에 측정한 COD값에 배출수량을 곱하여 그 값을 24시간으로 적산할 수 밖에 없어 매시간 정확한 COD 총량을 구하기는 사실상 어려운 일이다.Standard COD is a method of chemically oxidizing an organic substance at a high temperature and a strong acid using a strong oxidizing agent, using potassium permanganate (KMnO 4 ) and potassium dichromate (K 2 Cr 2 O 7 ). Association, Standard Methods for the Examination of Water and Wastewater, 17th Edition, American Public Health Association, Washington, DC, 1989, pp. 5-10]. However, it is difficult to make accurate measurement because it is difficult to decompose chemically stable chain organic materials, and there is a problem that the experimental error is increased due to chloride or nitrite. It is also greatly affected by changes in time and reaction conditions. In addition, it has to be carried out under extreme conditions such as high temperature and strong acid, and because it uses dangerous reagents such as mercury compound and sulfuric acid, it requires special care in handling and is dangerous to handle and does not solve the problem of waste liquid generated after the experiment. In addition, it is inefficient in terms of cost since a large amount of analyte used in one measurement is consumed. Above all, such a COD measurement method requires a measurement time of about 30 minutes to 1 hour, which is not suitable for real-time monitoring of the concentration of organic substances in a fluctuating water system. Continuous measurement and standardization of COD is urgently needed, but automatic measurement of discharge quantity is possible, but it takes much time for accurate measurement of actual COD value, so multiply the COD value measured at regular time by the discharge quantity. It is difficult to find the exact total COD amount every hour because it can only be integrated with time.
따라서, 표준 COD값과 높은 상관관계를 가지고 있으면서 연속측정이 가능한방법인 전극을 이용한 폐수 내 유기물농도 측정방법이 대두되었으며, 이 방법은 간단한 전극만으로 유기물질의 양을 측정함으로써 적외선 흡광도법이나 전위차 적정법을 이용하는 방법에 비하여 측정이 신속하며 보다 정확한 값을 제공해 줄 수 있다. 현재까지 유기물질에 대한 정량측정을 위해 유기물 산화의 촉매역할을 하고 있는 금속 및 이의 산화물질들을 전극으로 구성하여 유기물의 양을 간접적으로 측정할 수 있는 방법들이 빠르게 활용되어 오고 있다 [참조 Rossler-Fromme, R. and Scholz, F. 1996, Fresenius J. Anal. Chem 356:197-201; Lee, K.-H., 1999, Analytica Chemica Acta 398:161-171].Therefore, a method of measuring organic matter concentration in wastewater using an electrode, which has a high correlation with a standard COD value, and which is a method of continuous measurement has emerged. Compared to using the method, the measurement is faster and can provide more accurate values. To date, quantitative measurement of organic materials has been rapidly used to measure the amount of organic matter indirectly by forming electrodes and metals that act as catalysts for the oxidation of organic materials. , R. and Scholz, F. 1996, Fresenius J. Anal. Chem 356: 197-201; Lee, K.-H., 1999, Analytica Chemica Acta 398: 161-171.
이와 같은 전기화학적 측정법에 사용되는 금속전극은 다양하게 발달되어 왔다. 먼저, 높은 전위(>1.5Vvs.NHE)를 사용하여 OH 라디칼과 유기물과의 반응을 유도하는 전기화학적 산화방법에서는 산화주석, 산화납 전극 등이 사용되었다. 이와 같은 전극은 높은 산소발생 과전위를 가지고 있기 때문에 높은 전위를 인가할 수 있어 상대적으로 폭넓은 범위의 유기물을 분석할 수 있는 장점이 있으나 산화과정 동안에 높은 전압을 인가하기 때문에 장시간 운용시 전극의 활성도가 감소되어 바탕전류값이 불안정하고 유기물에 의한 오염문제가 발생하여 별도의 전극에 대한 세척단계가 필요하다.Metal electrodes used in such an electrochemical measurement method have been variously developed. First, tin oxide and lead oxide electrodes have been used in the electrochemical oxidation method using the high potential (> 1.5 V vs. NHE) to induce the reaction between OH radicals and organics. Such an electrode has the advantage of being able to apply a high potential because it has a high oxygen generation overpotential, so that it can analyze a wide range of organic matter, but because of the high voltage applied during the oxidation process, the activity of the electrode when operating for a long time Since the background current value is unstable and the contamination problem caused by organic matter occurs, a washing step for a separate electrode is required.
위와 같은 전기화학적 산화방식에 의하여 유기물의 양을 측정하는 방법 이외에 금속전극과 유기물과의 직접적인 반응성(reactivity)을 이용하여 유기물의 양을 측정할 수 있는데 이것은 주로 정전압전류법에 의해 가능하다. 이 방법에 사용되고 있는 전극은 구리(Cu), 니켈(Ni), 루세늄 (Ru), 이리듐 (Ir), 크롬(Cr), 은(Ag) 및이의 산화물과 합금 등을 사용하며, 이들은 일정한 산화전압 인가조건 하에서 표면에 산화촉매능이 우수한 금속산화물을 형성시켜 여러 형태의 유기물과 빠른 시간 내 반응할 수가 있기 때문에 알콜류(alcohols), 알디톨(alditols), 탄수화물 (carbohydrates), 알데하이드(aldehydes), 아민(amines), 아미노산(amino acid) 등과 같이 검출하기 어려운 유기물의 센서로서 많이 이용되어 왔다.In addition to the method of measuring the amount of organic matter by the above-described electrochemical oxidation method, the amount of organic matter can be measured by using direct reactivity between the metal electrode and the organic matter. This is mainly possible by the constant voltage current method. The electrodes used in this method include copper (Cu), nickel (Ni), ruthenium (Ru), iridium (Ir), chromium (Cr), silver (Ag), and their oxides and alloys. Metal oxides with excellent oxidation catalyst on the surface can be reacted with various types of organic materials under the conditions of applying voltage, so alcohols, alditols, carbohydrates, aldehydes, It has been widely used as a sensor for organic substances that are difficult to detect such as amines and amino acids.
그러나 이상의 전기화학적 유기물 산화 또는 COD 측정에 사용되는 금속 또는 이들의 산화물 전극들은 벌크(bulk)금속 또는 금속합금으로 이루어진 전극의 표면을 전기화학적으로 산화시키거나 내구성이 높은 백금, 금 또는 유리질 탄소전극 등의 표면에 이들 금속들의 산화물을 형성시킨 형태이다. 이들 전극은 장시간 사용할 경우 전극 표면이 오염되거나 파손되기도 하며 벌크전극의 지속적인 산화로 인하여 전극의 표면 변형이 심화되어 활성 표면적의 심각한 변화가 초래되어 안정적인 신호를 기대하기 어려운 경우가 대부분이다. 전술한 바와 같이 유기물 농도측정에 있어서 표준분석방법인 크롬법과 망간법에 비하여 짧은 측정시간과 폐액 등에 의한 2차오염 문제가 적은 전기화학적인 방법을 이용하는 것이 바람직하나 보다 신뢰성 있는 측정결과를 위해서는 보다 안정적이고 재현성 있는 특성을 지닌 전극의 사용이 필수적이다.However, the metals or oxide electrodes thereof used in the above-mentioned electrochemical organic oxidation or COD measurement are electrochemically oxidized on the surface of the electrode made of bulk metal or metal alloy, or durable platinum, gold or glassy carbon electrode. The oxides of these metals are formed on the surface of. These electrodes are often contaminated or damaged when used for a long time, and the surface deformation of the electrodes is deepened due to the continuous oxidation of the bulk electrode, which causes a serious change in the active surface area, which is difficult to expect a stable signal. As mentioned above, it is preferable to use the electrochemical method which has less secondary pollution problem due to short measurement time and waste liquid than the chromium method and manganese method, which is the standard analysis method, but more stable for more reliable measurement results. The use of electrodes with reproducible and reproducible properties is essential.
본 발명은 상기와 같은 문제점을 해결하기 위한 것으로서 안정성 및 재현성을 얻기 위하여 촉매능을 갖는 입자, 고분자 물질 및 전도체 물질을 혼합하고 고온에서 혼합 가열함으로써 얻어진 변성 복합재료전극(bulk-modified composite electrode)을 제공함에 있다.The present invention is to solve the above problems and to obtain a bulk-modified composite electrode obtained by mixing the particles having a catalytic capacity, a high molecular material and a conductor material and mixed heating at a high temperature in order to obtain stability and reproducibility In providing.
본 발명의 부수적인 목적은 상기 방법을 이용하여 변동수계에서의 유기물질의 농도를 실시간으로 모니터링할 수 있는 유기물질 농도, 즉 전기화학적 산소 요구량 측정용 셀 및 시스템을 제공함에 있다.An additional object of the present invention is to provide an organic material concentration, ie, an electrochemical oxygen demand measurement cell and system, which can monitor the concentration of organic material in a variable water system in real time using the above method.
도 1은 흐름주입 분석에 사용할 수 있는 셀의 분해사시도이다.1 is an exploded perspective view of a cell that can be used for flow injection analysis.
도 2는 회분식 분석에 사용할 수 있는 셀의 사시도이다.2 is a perspective view of a cell that can be used for batch analysis.
도 3은 전기화학적 산소요구량 측정용 시스템을 나타낸 모식도이다.Figure 3 is a schematic diagram showing a system for measuring the electrochemical oxygen demand.
도 4는 금속변성 복합재료전극을 사용하여 흐름주입법으로 분석한 전기화학적 산소요구량 측정값과 표준 화학적 산소요구량 측정값의 상관관계도이다.4 is a correlation diagram between the electrochemical oxygen demand measurement value and the standard chemical oxygen demand measurement value analyzed by the flow injection method using a metal modified composite electrode.
도 5는 회분식 분석시 발생된 전류값과 표준 화학적 산소요구량 측정값의 상관관계도이다.FIG. 5 is a correlation diagram of current values generated during batch analysis and standard chemical oxygen demand measurement values. FIG.
도 6은 금속산화물변성 복합재료전극을 사용하여 흐름주입법으로 분석한 전기화학적 산소요구량 측정값과 표준 화학적 산소요구량 측정값의 상관관계도이다.6 is a correlation diagram between an electrochemical oxygen demand measurement value and a standard chemical oxygen demand measurement value analyzed by a flow injection method using a metal oxide modified composite electrode.
본 발명의 상기와 같은 목적은The above object of the present invention
전기화학적 방법에 의해 COD를 측정하기 위한,For measuring COD by electrochemical method,
촉매능을 갖는 분말과;Powder having catalytic activity;
유기용매에 대한 내성을 갖는 고분자 수지와;A polymer resin having resistance to an organic solvent;
전도성을 갖는 카본 블랙 및 그라파이트 중에서 선택된 어느 하나를 혼합하여 고온에서 성형됨을 특징으로하는 복합재료 전극에 의해 달성된다.It is achieved by a composite electrode characterized in that any one selected from conductive carbon black and graphite is mixed to form at high temperatures.
아직까지 상기의 금속변성형태의 전극을 COD 측정에 이용한 예는 지금까지 없었을 뿐만 아니라, 이 전극은 표면변성전극이나 변성 탄소 분말(carbon paste) 전극에 비해 전도체 역할을 하는 탄소와 촉매 변성체의 입자가 고분자 매질 내에 고르게 분포된 형태로 얻어지기 때문에, 촉매 변성체에 의한 빠른 반응성은 물론 표면에 제한적으로 노출된 촉매 변성체의 산화시 전극표면에서만 활성화가 진행되므로 전극 신호의 빠른 안정화와 함께 재현성을 확보할 수가 있어 빠르고 정확한 COD 측정에 적합하다. 또한 이 전극은 표면을 연마함으로써 새로운 전극 표면을 일정하게 재생할 수가 있어 다양한 유기물 산화반응의 신호 재현성을 높일 수 있고 장기간 운용에도 적합하다.Until now, there have been no examples of using the above-described metal-modified electrode for COD measurement, and the electrode is composed of particles of carbon and catalyst modified bodies that act as conductors compared to surface-modified electrodes or modified carbon paste electrodes. Is obtained in an evenly distributed form in the polymer medium, so that the activation proceeds only at the electrode surface during oxidation of the catalytic modified body exposed to the surface as well as the rapid reactivity by the catalytic modified body, thereby providing fast stabilization and reproducibility. It can be secured and is suitable for fast and accurate COD measurement. In addition, the electrode can be polished to regenerate the surface of a new electrode, thereby improving the signal reproducibility of various organic oxidation reactions, and is suitable for long-term operation.
상기한 금속변성 복합재료전극의 제조 방법은 다음과 같다.The manufacturing method of the metal modified composite electrode is as follows.
금속변성 복합재료전극의 제조에 사용되는 변성체로는 유기물 촉매인 금속입자, 예를 들면, 구리, 니켈, 니켈-티타늄, 루비듐, 이리듐, 크롬, 납, 은 등을 들 수 있으며, 이들 중에서 선택된 하나 이상을 첨가할 수 있다. 전극의 매질 역할을 하는 고분자 수지로는 유기용매에 대한 내성이 강한 고분자 수지, 예를 들면, 테플론(teflon), 폴리클로로트리플루오르에틸렌(Kel-F, polychlorotrifluoro- ethylene), 폴리스티렌(PS, polystylene), 폴리에틸렌(PE, polyethylene), 폴리프로필렌(PP, polypropylene), 폴리비닐클로라이드(PVC, polyvinylchloride) 및 폴리에테르에테르케톤(PEEK, polyetheretherketone) 등을 들 수 있으며, 이들 중에서 선택된 하나 이상을 사용할 수 있다. 전도성물질로는 카본 블랙(carbon black) 또는 그라파이트 (graphite) 분말을 사용할 수 있다. 본 실시예에서는 변성체로서 구리입자와 매질로서 PEEK를, 전도체로서 carbon black 혹은 graphite를 사용하여 혼합, 열성형하여 금속변성 복합재료전극을 제조하였다. 전극의 형태나 크기는 달리할 수 있다.The modified body used in the preparation of the metal-modified composite electrode includes metal particles, for example, copper, nickel, nickel-titanium, rubidium, iridium, chromium, lead, and silver, which are organic catalysts. The above can be added. The polymer resin serving as the medium of the electrode is a polymer resin that is highly resistant to organic solvents such as teflon, polychlorotrifluoroethylene (Kel-F, polychlorotrifluoroethylene), and polystyrene (PS, polystylene). , Polyethylene (PE, polyethylene), polypropylene (PP, polypropylene), polyvinyl chloride (PVC, polyvinylchloride) and polyether ether ketone (PEEK, polyetheretherketone), and the like, and the like. As the conductive material, carbon black or graphite powder may be used. In this embodiment, a metal modified composite electrode was manufactured by mixing and thermoforming by using copper particles as a modified body, PEEK as a medium, and carbon black or graphite as a conductor. The shape or size of the electrode can vary.
각 성분을 혼합하는 방법에는 입자상태로 직접 혼합하는 방법, 용매를 이용하여 혼합하는 방법 및 사출성형을 이용하여 혼합하는 방법이 있다. 각각의 혼합방법에 대하여 간단히 설명한다.Methods of mixing each component include a method of directly mixing in a particulate state, a method of mixing using a solvent, and a method of mixing using injection molding. Each mixing method is briefly described.
분말상태에서 직접 혼합하는 방법은 혼합조건에 따라 고분자, 탄소, 촉매를동시에 섞어서 혼합하는 방법과 고분자와 탄소, 고분자와 촉매, 촉매와 고분자를 먼저 혼합시킨 후 나머지 한가지를 혼합시키는 방법이 있다. 우선 혼합 전 각각의 분말들을 체(sieve)를 이용하여 작은크기로 균일화시키고 효과적인 혼합을 위하여 볼밀(ball-mill)을 사용하여 12시간이상 충분히 섞어준다. 혼합 후 원하는 크기와 형태로 제작된 금형에 넣고 가열하고 압력을 가하여 펠렛(pellet)으로 성형하였다. 금형의 가열온도는 고분자의 녹는점이나 유리 전이온도보다 약간 높은 온도로 설정할 수 있는데 고분자물질의 성분에 따라 유리 전이온도가 다르므로 성형온도는 고분자의 특성에 따라 달리 적용될 수 있다. PEEK를 사용한 본 실시예의 경우에는 약 400℃ 에서 성형이 이루어졌다. 상기 고분자 매질은 유기용매에 대한 내성이 강하지만 함량이 지나칠 경우 전도도가 떨어지고 경도가 낮아 가공이나 연마가 용이하지 않으므로 일정한 함량을 유지해야 하고 carbon black 또는 graphite같은 전도체 물질을 반드시 첨가해 주는 것이 바람직하다. 변성체인 금속촉매의 경우에 있어서도 함량이 증가하면 촉매능력의 향상으로 인해 이상적일 것이나 그 함량이 지나치면 열성형 과정에서 금속입자간의 뭉침현상을 유발하고 매질속에 금속입자의 효과적인 분산을 기대할 수 없다. 또한 전도성물질인 경우에 있어서 전도도의 향상을 위해서 많은 양을 포함시키는 것이 이상적이나 고분자와 탄소의 혼합에 제한을 받게 되어 그 함량을 조절해야만 한다. 따라서 가능한 한 변성체인 금속입자의 함량이 많으면서 금속입자간의 뭉침현상이 잘 나타나지 않는 조건에서 매질과 변성체 및 전도성물질의 함량을 결정하는 것이 바람직하며 본 실시예에서는 대략 그 중량비가 PEEK 60%, 구리 25%, graphite 15% 되도록 혼합하였다.Direct mixing in powder state includes mixing the polymer, carbon, and catalyst at the same time according to the mixing conditions, and mixing the polymer and carbon, the polymer and the catalyst, the catalyst and the polymer first, and then mixing the other one. First, before mixing, the powders are homogenized to a small size using a sieve and mixed well for more than 12 hours using a ball mill for effective mixing. After mixing, the mixture was put into a mold manufactured in a desired size and shape, and heated and pressed to form a pellet. The heating temperature of the mold can be set to a temperature slightly higher than the melting point or glass transition temperature of the polymer. Since the glass transition temperature varies depending on the components of the polymer material, the molding temperature can be applied differently depending on the characteristics of the polymer. In the case of this example using PEEK, molding took place at about 400 ° C. The polymer medium has a strong resistance to organic solvents, but if the content is excessive, the conductivity is low and the hardness is not easy to be processed or polished. . In the case of a modified metal catalyst, an increase in the content may be ideal due to the improvement of the catalytic capacity, but when the content is too high, it causes aggregation of metal particles in the thermoforming process and effective dispersion of the metal particles in the medium cannot be expected. In addition, in the case of a conductive material, it is ideal to include a large amount in order to improve conductivity, but it is limited to the mixture of polymer and carbon, and thus the content must be controlled. Therefore, it is desirable to determine the content of the medium, the modified body, and the conductive material under the condition that the content of the metal particles, which are modified as much as possible, and the aggregation between the metal particles is not easily seen, in this embodiment, the weight ratio is approximately PEEK 60%, 25% copper and 15% graphite were mixed.
상기 언급된 분말들의 보다 균일한 혼합을 위해서는 유기용매를 사용할 수가 있다. 사용하고자 하는 고분자가 용해 가능한 용매를 준비한 후 고분자를 녹여 점도가 큰 고분자 용액을 만든 후에 칭량된 탄소와 금속촉매를 동일한 용매에 적신 후 고분자 용액에 첨가한다. 이 때 분쇄혼합기(homogenizer)를 사용하여 탄소와 촉매가 잘 분산되도록 혼합한 후에 고분자가 녹지 않는 용매를 선택하여 고분자 혼합용액만을 석출하여 건조시킨 후 분쇄기를 이용하여 분쇄한다. 이 후 분쇄된 혼합물을 원하는 크기와 형태의 금형에 넣고 가열하여 성형하는 것이 가능하다.Organic solvents can be used for more uniform mixing of the aforementioned powders. After preparing a solvent in which the polymer to be used is soluble, the polymer is dissolved to make a polymer solution having a high viscosity, and then the weighed carbon and the metal catalyst are wetted in the same solvent and added to the polymer solution. At this time, using a homogenizer to mix the carbon and the catalyst to be dispersed well, select a solvent in which the polymer is not dissolved to precipitate and dry only the polymer mixed solution and then pulverize using a grinder. After this, the pulverized mixture can be put into a mold of a desired size and shape and heated to be molded.
스크루에 의한 혼합 사출기를 이용한 방법도 매질인 고분자와 금속촉매 및 전도성 물질인 탄소(carbon black 또는 graphite)를 혼합 성형하는 데 바람직하다.The method using a screw injection molding machine is also preferable for mixing and molding a polymer as a medium, a metal catalyst and carbon (carbon black or graphite) as a conductive material.
상기의 전극을 이용하여 전기화학적 반응셀을 구성한 결과를 도 1과 도 2에 나타내었다. 작업전극은 금속변성 복합재료전극이고 대전극으로는 백금전극 또는 스테인레스강(stainless steel)을 사용할 수 있으며 기준전극으로는 일반적으로 사용하는 은/염화은 (Ag/AgCl) 전극 또는 포화칼로멜(SCE)을 사용할 수 있다. 상기 작업전극 표면은 간단한 연마에 의해서 손쉽게 표면을 재생할 수 있다. 사용되는 전해질은 전극의 성상에 따라서 또는 분석대상시료와의 반응성에 따라서 수산화나트륨(NaOH), 황산수용액(H2SO4) 및 황산나트륨(Na2SO4) 등을 한가지 이상 선택하여 사용할 수 있다. 이 작업전극을 사용하여 반응조의 형태만 달리하면 회분식 또는 연속식으로 측정가능하다.The results of the electrochemical reaction cell using the electrode are shown in FIGS. 1 and 2. The working electrode is a metal-modified composite electrode, and the counter electrode may be made of platinum electrode or stainless steel, and the reference electrode is a silver / silver chloride (Ag / AgCl) electrode or saturated caramel (SCE). Can be used. The working electrode surface can be easily regenerated by simple polishing. As the electrolyte used, one or more sodium hydroxide (NaOH), aqueous sulfuric acid solution (H 2 SO 4 ), sodium sulfate (Na 2 SO 4 ), etc. may be selected and used depending on the properties of the electrode or the reactivity with the sample to be analyzed. By using this working electrode, it can be measured batchwise or continuously only by changing the shape of the reactor.
도 1은 흐름주입 분석법에 사용하기 위한 박막셀(Thin-layer cell)이다. 박막셀은 금속변성 복합재료전극, 기준전극 및 대전극의 3전극을 포함하는 셀로서, 상기 금속변성 복합재료전극의 일면과 상기 기준전극이 부착된 상기 대전극의 일면 사이에 분석대상시료가 유입될 수 있는 공간이 형성된 절연막이 구비되며, 상기 분석대상시료가 유입 및 배출되는 유입구 및 배출구가 상기 대전극을 관통하는 구조를 갖는다. 이러한 셀은 전극반응을 보다 빠르게 하고, 셀 크기 및 분석물질의 양을 최소화하여 반응성을 높임으로써 저농도 및 고농도 유기물질의 양을 보다 빠르고 정확하게 측정할 수가 있다. 즉, 전극부분에서의 반응은 분석물질의 질량이동(mass transfer)과 전극반응속도(kinetics)의 상관관계에 의한 영향을 받게 되는데, 상기 언급된 반응셀의 경우 분석물질의 확산속도는 일정하게 유지하고 셀 용량 및 분석물질의 양을 최소한으로 줄여 분석물질의 질량이동 및 셀 저항의 영향을 최소화하면 전극부위에서의 반응을 신속하게 유도할 수 있다. 측정방법은 기준전극과 대전극간 정전압전류법에 의해 가능하다. 도 1에서 작업전극(1)으로 테플론 혹은 호마이카 수지에 금속변성 복합재료전극을 몰딩시켜 사용하며, 기준전극(2)은 Ag/AgCl 전극을 사용한다. 대전극(3)은 셀블록 전체가 스테인레스강으로 되어있으며 작업전극과 대전극사이에는 일정한 유로가 형성될 수 있도록 테플론막(4)이 놓여져 있다. 셀전체는 나사에 의해 보호판(7)과 함께 압착되어 있다. 분석대상시료는 주입구(5)로 들어가 셀을 통과하여 배출구(6)쪽으로 나가게 된다.1 is a thin-layer cell for use in a flow injection assay. The thin film cell is a cell including three electrodes of a metal modified composite electrode, a reference electrode, and a counter electrode, and an analyte sample flows between one surface of the metal modified composite electrode and one surface of the counter electrode to which the reference electrode is attached. An insulating film having a space therein is provided, and an inlet and an outlet through which the analyte sample is introduced and discharged have a structure passing through the counter electrode. These cells can measure the amount of low and high concentrations of organic materials faster and more accurately by increasing electrode reactions and minimizing cell size and analyte levels to increase reactivity. That is, the reaction at the electrode part is affected by the correlation between the mass transfer of the analyte and the kinetics of the electrode. In the reaction cell, the diffusion rate of the analyte is kept constant. In addition, minimizing the effects of mass transfer and cell resistance of the analyte by minimizing the cell capacity and the amount of analyte can lead to a rapid reaction at the electrode. The measuring method is possible by the constant voltage current method between the reference electrode and the counter electrode. In FIG. 1, a metal modified composite electrode is molded in a Teflon or Homica resin as the working electrode 1, and the reference electrode 2 uses an Ag / AgCl electrode. The counter electrode 3 is made of stainless steel as a whole of the cell block, and a Teflon film 4 is placed to form a constant flow path between the working electrode and the counter electrode. The whole cell is crimped together with the protective plate 7 by screws. The sample to be analyzed enters the inlet 5 and passes through the cell to the outlet 6.
도 2는 회분법으로 측정할 수 있는 벌크형 전기화학적 측정셀로서 반응조(8)에 작업전극(1), 기준전극(2), 대전극(3)의 3전극을 일정간격 이격시켜 배치한 구성을 갖는다. 분석대상시료는 주입구(5)로 유입되고 일정량이 채워지면배출구(6)를 통하여 배출된다. 이 셀의 작업전극과 기준전극에 일정전압을 인가한 후에 전류 혹은 전하량법에 의해 유기물의 양을 측정할 수가 있다.2 is a bulk type electrochemical measuring cell which can be measured by a batch method, in which the three electrodes of the working electrode 1, the reference electrode 2, and the counter electrode 3 are arranged in the reaction tank 8 at a predetermined interval. Have The sample to be analyzed is introduced into the inlet 5 and discharged through the outlet 6 when a certain amount is filled. After a constant voltage is applied to the working electrode and the reference electrode of this cell, the amount of organic matter can be measured by current or charge amount method.
박막셀이나 벌크형 셀에서 작업전극의 인가전압범위는 금속변성 복합재료전극의 성상에 따라 다양하게 적용시킬 수가 있다. 또한 경우에 따라서는 작업전극을 하나 이상 사용하여 폐수내 유기물의 특성에 따라 반응성이 우수한 작업전극을 선택하게 함으로써, 정확성을 높이는 방법도 사용될 수 있다.In the thin film cell or the bulk cell, the applied voltage range of the working electrode can be variously applied depending on the properties of the metal modified composite electrode. In some cases, one or more working electrodes may be used to select a working electrode having excellent reactivity according to the characteristics of organic matter in the wastewater, thereby increasing the accuracy.
한편 도 3은 전기화학적 방법에 의해 유기물의 농도를 분석하는 전기화학적 산소요구량 측정시스템을 도식화한 것이다. 측정셀에 유입되는 것들은 기본전해질 (10), 표준시료(11), 희석용전해질(12), 분석대상시료(13)로서 다채널 펌프(20) 또는 여러개의 단채널 펌프를 통하여 유입된다. 분석대상시료(13)는 펌프에 유입되기 전 전처리장치 (도면 미도시, 공개특허번호 10-2001-0086986)를 거쳐 여과되며, 시료원수관(21) 및 시료배수관(22)을 통하여 유입 및 배출된다. 유기물 농도 측정을 위한 분석대상시료(13) 또는 검정(calibration)을 위한 표준시료(11)는 희석용전해질과 함께 혼합되어 기본전해질 (10)과 비슷한 농도를 유지하면서 셀(100)로 유입된다. 이러한 선택적인 조작은 각각의 유로에 설치되어 있는 밸브(23,24)와 제어부(25)를 제어함으로써 이루어진다. 제어부(25)의 제어를 받는 자동주입기(26)는 바탕값을 설정해주는 기본전해질(10)을 일정하게 셀(100)로 흘려보내주다가 시료(12와 혼합된 11 또는 12와 혼합된 13) 측정시에는 유로를 바꾸어 셀(100)로 흘려보내주는 역할을 한다. 정전압기(27)는 일정전압을 반응셀에 인가해주며, 측정이끝나거나 측정할 필요가 없는 시료는 배출구(28)를 통하여 외부로 배출되며, 셀(100)의 반응시 나오는 전류값은 제어부(25)에서 기록하여 COD값으로 환산해 준다.On the other hand, Figure 3 is a schematic diagram of the electrochemical oxygen demand measurement system for analyzing the concentration of organic matter by the electrochemical method. What is introduced into the measurement cell is introduced through the multi-channel pump 20 or a plurality of short-channel pumps as the basic electrolyte (10), the standard sample (11), the dilute electrolyte (12), the sample to be analyzed (13). The sample 13 to be analyzed is filtered through a pretreatment device (not shown in the drawing, Patent Publication No. 10-2001-0086986) before entering the pump, and is introduced and discharged through the sample water supply pipe 21 and the sample drain pipe 22. do. The analyte sample 13 for measuring organic concentration or the standard sample 11 for calibration is mixed with the dilute electrolyte and introduced into the cell 100 while maintaining a concentration similar to that of the basic electrolyte 10. This selective operation is achieved by controlling the valves 23 and 24 and the control unit 25 provided in the respective flow paths. The autoinjector 26 under the control of the control unit 25 constantly flows the basic electrolyte 10 that sets the background value to the cell 100, and measures 11 or 13 mixed with the sample 12. The city changes the flow path and serves to flow to the cell 100. The constant voltage generator 27 applies a constant voltage to the reaction cell, and the sample which is not measured or needs to be measured is discharged to the outside through the discharge port 28, and the current value generated during the reaction of the cell 100 is controlled. Record at (25) and convert to COD value.
이하에서는 실시예를 통하여 본 발명을 더욱 구체화하나, 본 발명이 하기의 실시예에 의하여 한정되는 것은 아니다.Hereinafter, the present invention will be further illustrated by examples, but the present invention is not limited to the following examples.
우선, PEEK 60중량부(450PF, VICTREX Co, Ltd. USA), 구리입자 25중량부, 그라파이트 15중량부를 혼합한 후 볼밀을 이용하여 12시간 동안 충분히 혼합하였다. 혼합 후, 혼합된 분말을 금형에 넣고 400℃로 가열하고, 1 ton의 압력을 가하여 직경 1㎝, 높이 0.5㎝의 펠렛으로 성형하여 금속변성 복합재료전극을 제조하였다.First, 60 parts by weight of PEEK (450PF, VICTREX Co, Ltd. USA), 25 parts by weight of copper particles, and 15 parts by weight of graphite were mixed, and then sufficiently mixed for 12 hours using a ball mill. After mixing, the mixed powder was placed in a mold and heated to 400 ° C., and a pressure of 1 ton was applied to form a pellet having a diameter of 1 cm and a height of 0.5 cm to prepare a metal-modified composite electrode.
제조된 금속변성 복합재료전극을 두가지 형태의 셀에 적용시켜 각각 실시예 1과 실시예 2로 나타내었다.The prepared metal modified composite electrode was applied to two types of cells, and is shown in Examples 1 and 2, respectively.
실시예 1Example 1
실시예 1은 흐름주입 분석법 즉, 도 1의 박막셀 및 도 3의 측정시스템을 적용시킨 예이다.Example 1 is an example in which the flow injection analysis method, that is, the thin film cell of FIG. 1 and the measurement system of FIG. 3 are applied.
우선, 작업전극으로는 상기에서 제조한 금속변성 복합재료전극을, 대전극으로는 스테인레스강(stainless steel)을, 기준전극으로는 은/염화은 전극을 사용하였으며, 표준 전해질용액으로는 수산화나트륨 용액을 사용하여 박막셀을 구성하였다. 분석대상시료로는 하천수, 하수종말처리장 시료, 염색폐수를 그 대상으로 하였으며, 먼저 각 시료에 대하여 중크롬산칼륨에 의한 표준 COD측정법으로 COD값을 측정하였다. 다음으로는 작업전극에 약 550~600mV (vs. Ag/AgCl)의 전압이 인가된 상태에서 상기 시료들을 박막셀에 주입하였으며, 이때 작업전극과 대전극 사이에서 발생되는 전류값을 모니터링하였다. 발생된 전류값은 피크형태로 나타나며 기본전해질만 유입시 나타나는 바탕 전류값으로부터 피크까지의 높이를 전기화학적 산소요구량(EOD; Electrochemical Oxygen Demand)으로 정의하였다. 상기 표준 COD측정법에 의한 COD측정값과 박막셀에 의한 EOD측정값과의 관계를 도 4에 나타내었다.First, a metal modified composite electrode prepared above as a working electrode, stainless steel as a counter electrode, silver / silver chloride electrode as a reference electrode, and sodium hydroxide solution as a standard electrolyte solution were used. To form a thin film cell. Samples to be analyzed were river water, sewage treatment plant samples, and dyeing wastewater. COD values were measured for each sample by standard COD measurement using potassium dichromate. Next, the sample was injected into the thin film cell while a voltage of about 550 to 600 mV (vs. Ag / AgCl) was applied to the working electrode, and the current value generated between the working electrode and the counter electrode was monitored. The generated current value is in the form of a peak, and the height from the background current value that appears when only the basic electrolyte is introduced is defined as the electrochemical oxygen demand (EOD). The relationship between the COD measurement value by the standard COD measurement method and the EOD measurement value by the thin film cell is shown in FIG. 4.
도 4에서 X축은 중크롬산칼륨에 의한 표준 COD측정방법으로 각각의 농도에 대해 3회 반복한 산술평균값이고 Y축은 박막셀에 의한 EOD측정방법으로 각각의 농도에 대해 3회 반복한 산술평균값으로 나타낸 것이다.In FIG. 4, the X-axis is a standard COD measurement method using potassium dichromate, and the arithmetic mean value is repeated three times for each concentration, and the Y-axis is represented by an arithmetic mean value repeated three times for each concentration by the EOD measurement method using a thin film cell. .
상기 측정에 사용된 3종류의 폐수에 대하여 크롬법으로 측정한 표준 COD값과 박막셀을 사용하여 측정한 EOD값을 비교했을 때 각 폐수에서 r=0.99 로 나타났다. 즉, EOD값은 표준 COD값과 높은 상관관계를 가지고 있음을 알 수 있었다. 또한 전극의 표면을 연마후에도 동일한 결과를 얻을 수 있었다. 따라서, 이러한 결과는 금속변성 복합재료전극과 유기물과의 반응을 측정하여 얻은 EOD값이 EOD/COD 비율에 의해서 효과적으로 COD값으로 전환될 수 있어 COD값을 연속적으로 측정할 수 있음을 의미하는 것이다.When the standard COD values measured by the chromium method and the EOD values measured using the thin film cell were compared with respect to the three types of wastewater used in the above measurement, r = 0.99 was found in each wastewater. That is, the EOD value was found to have a high correlation with the standard COD value. The same result was obtained even after polishing the surface of the electrode. Therefore, this result means that the EOD value obtained by measuring the reaction between the metal-modified composite electrode and the organic material can be effectively converted to the COD value by the EOD / COD ratio, so that the COD value can be continuously measured.
실시예 2Example 2
실시예 1에서 사용한 작업전극을 회분식 방법, 즉 벌크형 전기화학셀에 적용시킨 예이다. 기준전극으로는 은/염화은 전극을 사용하였고 대전극으로는 백금전극을 사용하였으며, 표준 전해질용액으로는 수산화나트륨 용액을 사용하여 벌크형 셀을 구성하였다. 분석대상시료로는 실시예 1에서 사용한 하수종말처리장 시료를 각각 다른 비율로 희석시켜 사용하였다. 작업전극에 600mV (vs. Ag/AgCl)의 전압을 인가한 후 전류값이 평형상태에 도달하였을 때의 평균값(steady-state current)을 측정하였다. 이러한 작업을 각 시료의 농도에 따라 3회 반복측정한 값의 평균치를 산출하였다. 각 시료에 대한 표준 COD값을 3회 측정하고 그 산술평균값과 평균값을 도 5에 나타내었다. COD값과 평균값의 비교 결과 상관계수는 r=0.99로 나타났다.The working electrode used in Example 1 was applied to a batch method, that is, a bulk type electrochemical cell. A silver / silver chloride electrode was used as a reference electrode, a platinum electrode was used as a counter electrode, and a sodium hydroxide solution was used as a standard electrolyte solution. As samples to be analyzed, samples of sewage treatment plants used in Example 1 were diluted at different ratios. After applying a voltage of 600mV (vs. Ag / AgCl) to the working electrode, the average value (steady-state current) when the current value reached an equilibrium state was measured. This operation was calculated as the average of three repeated measurements according to the concentration of each sample. The standard COD value for each sample was measured three times and the arithmetic mean value and average value are shown in FIG. 5. As a result of comparing the COD value and the mean value, the correlation coefficient was r = 0.99.
실시예 3Example 3
작업전극으로 금속변성 복합재료 전극대신 금속산화물 변성 복합재료전극을 사용하여 흐름주입 분석법에 의해 적용시킨 예이다. 작업전극으로는 산화니켈(NiO)을, 폴리머로는 폴리스티렌(polystytene)과 폴리비닐벤젠(polyvinylbenzene)을 사용하였으며 전도체로서 카본블랙을 사용하여 제조하였다. 각 조성은 산화니켈이 19.21%, 폴리머가 75.76%, 카본블랙이 5.06%이고 전해질은 실시예 1과 동일하게 수산화나트륨 0.1M을 사용하였다. 기준전극은 수은/산화수은(Hg/HgO)전극을 사용하였고 대전극은 실시예 1에서 사용한 것과 동일하게 적용하였다. 작업전극에 인가한 전압의 크기는 600mV였다. 작업전극의 크기(직경 3.0mm)와 주입된 시료양(20uL), 유속(0.5mL/min) 등은 실시예 1과는 달리하여 측정하였다. 측정시료는 실시예 1에서 사용한 하수처리장 시료 원수(100%)를 80%, 60%, 40% ,20%로 각각 희석하여 각 농도에 해당하는 EOD값을 얻어 표준 크롬법에 의한 COD값과 비교하였고 EOD의 측정값은 3회실시하여 평균값을 산출한 결과를 도 6에 나타내었다.It is an example applied by flow injection analysis using metal oxide modified composite electrode instead of metal modified composite electrode as working electrode. Nickel oxide (NiO) was used as a working electrode, and polystyrene (polystytene) and polyvinylbenzene (polyvinylbenzene) were used as a polymer, and carbon black was used as a conductor. Each composition was 19.21% nickel oxide, 75.76% polymer, 5.06% carbon black, and 0.1M sodium hydroxide was used in the same manner as in Example 1. Mercury / mercury oxide (Hg / HgO) electrode was used as the reference electrode, and the counter electrode was applied in the same manner as in Example 1. The magnitude of the voltage applied to the working electrode was 600 mV. The size of the working electrode (diameter 3.0mm), the injected sample amount (20uL), the flow rate (0.5mL / min) and the like was measured differently from Example 1. The measured sample was diluted with 80%, 60%, 40%, and 20% of raw water (100%) of the sewage treatment plant sample used in Example 1 to obtain an EOD value corresponding to each concentration, and compared with the COD value by standard chromium method. The measured value of EOD was performed three times, and the average value was calculated in FIG. 6.
이러한 결과로부터 금속변성 복합재료전극을 이용한 3전극의 회분식 방법 역시 평균값/COD 비율에 의해서 효과적으로 COD값으로 전환될 수 있으며, 전류값이 일정한 상태에서는 시간에 따라 적분이 가능함으로 전하량법으로도 유기물의 농도를 측정할 수 있음을 의미하는 것이다.From these results, the batch method of the three-electrode using the metal-modified composite electrode can also be effectively converted to COD value by the average value / COD ratio, and it is possible to integrate over time when the current value is constant. It means that the concentration can be measured.
본 발명에 의하면 수질 내 유기물의 정량분석을 수행할 수 있으므로, 기존의 망간법 또는 크롬법에 비하여 짧은 측정시간 내에 수질환경의 오염지표로 사용되는 유기물의 농도 측정할 수 있게 된다. 전극표면에서 촉매변성체와 전도성 입자가 고르게 분포된 형태이기 때문에 전극신호의 빠른 안정화와 재현성을 확보할 수 있어 빠르고 정확한 COD측정에 적합하다. 또한 장기간 운용시에 전극표면이 비활성화가 되어 반응속도가 저하될 경우에도 별도의 전극 세척장치가 필요없이 전극의 표면만 간단히 연마함으로써 전극을 장기간 재현성 있게 사용할 수가 있어 유기물의 양을 24시간 내내 모니터링 할 수 있다. 뿐만 아니라 전극을 이용한 전기화학적 산소요구량 측정 시스템은 소모되는 시약을 최소화하여 유지관리 비용을 줄이고 안전한 시약을 사용함으로써 폐액 등의 2차 오염물질이 거의 발생하지 않는 장점을 가진다.According to the present invention, since the quantitative analysis of organic matter in water can be performed, it is possible to measure the concentration of organic matter used as a pollution indicator of the water environment within a short measurement time compared to the conventional manganese method or chromium method. Since the catalyst densities and conductive particles are evenly distributed on the surface of the electrode, fast stabilization and reproducibility of the electrode signal can be ensured, which is suitable for fast and accurate COD measurement. In addition, even if the surface of the electrode is deactivated during long-term operation and the reaction rate decreases, the electrode surface can be used reproducibly for a long time by simply polishing the surface of the electrode without the need for a separate electrode cleaning device. Can be. In addition, the electrochemical oxygen demand measurement system using the electrode has the advantage that the secondary pollution such as waste liquid is generated rarely by minimizing the consumed reagents, reducing maintenance costs and using a safe reagent.
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|---|---|---|---|---|
| KR100776981B1 (en) * | 2006-06-23 | 2007-11-21 | 건국대학교 산학협력단 | Surface renewable iridium oxide composite hydrogen ion electrodes and their preparation methods |
| KR101202362B1 (en) * | 2010-03-02 | 2012-11-16 | 주식회사 과학기술분석센타 | Catalyst Including Pt-Ru of Working Electrode for COD Measuring Sensor and Manufacturing Process thereof |
| WO2015026104A1 (en) * | 2013-08-20 | 2015-02-26 | 주식회사 이지센싱 | Hydrogen ion electrode composed of composite material of nano iridium oxide and polymer resin and enabling surface regeneration, ph sensor using same, and method for manufacturing same |
| KR20150021454A (en) * | 2013-08-20 | 2015-03-02 | 주식회사 이지센싱 | Surface Renewable Hydrogen Ion Electrodes Made of Composite of Nano-Iridium Oxide and Polymer Resin, pH Sensor Using the Same and Preparation Method Thereof |
| KR101519359B1 (en) * | 2014-11-03 | 2015-05-13 | 길주형 | On-Line Multipurpose Chloride Analyzer |
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| WO2010132957A1 (en) * | 2009-05-22 | 2010-11-25 | Aqua Diagnostic Holdings Pty Ltd | Water analysis |
| WO2011000572A1 (en) | 2009-07-02 | 2011-01-06 | Patenthandel Portfoliofonds I Gmbh & Co. Kg | Method and device for detecting long-term biological effects in cells |
| CN102706946B (en) * | 2011-03-28 | 2014-09-17 | 同济大学 | Method for rapidly determining COD of waste water difficult to be oxidized |
| ES2595114B1 (en) * | 2015-06-26 | 2017-10-09 | Adasa Sistemas, S.A.U. | Sensor, probe and equipment for chemical demand measurement of soluble oxygen based on amperometric detection for water quality control applications |
| CN112903772B (en) * | 2021-01-16 | 2022-01-04 | 中国科学院南京土壤研究所 | In-situ initial measurement and prejudgment method for TOC concentration of solution |
| CN114858879A (en) * | 2022-04-20 | 2022-08-05 | 广东工业大学 | Method and device for rapidly detecting compost maturity |
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| JPS552959A (en) * | 1978-06-22 | 1980-01-10 | Sharp Corp | Automatic cod measuring device |
| JPS57152479A (en) * | 1981-03-16 | 1982-09-20 | Toyo Soda Mfg Co Ltd | Production of gas diffusion electrode |
| JPS6052759A (en) * | 1983-08-31 | 1985-03-26 | Terumo Corp | Oxygen sensor |
| JPS60127448A (en) * | 1983-12-13 | 1985-07-08 | Sumitomo Metal Ind Ltd | Cod measuring method and apparatus therefor |
| JPH08145944A (en) * | 1994-11-18 | 1996-06-07 | Nakano Vinegar Co Ltd | Electrical analyzing method for cod and cod measuring device |
| KR100247133B1 (en) * | 1997-12-24 | 2000-06-01 | 김혜정 | Chemical oxygen demand analyzer of industry waste-water using robot and analyzing method |
| KR100277170B1 (en) * | 1998-04-23 | 2001-09-17 | 박종만 | Metal modified carbon electrode |
| JP2000046793A (en) * | 1998-07-23 | 2000-02-18 | Trp:Kk | System for evaluating water fouling |
| JP3495994B2 (en) * | 2001-02-02 | 2004-02-09 | 飯島電子工業株式会社 | Method and apparatus for measuring chemical oxygen demand |
| KR20030003849A (en) * | 2001-07-04 | 2003-01-14 | 주식회사 에코아이티이십일 | Copper electrode-based electrochemical sensor for measurement of COD and the method of measuring of COD and the automatic analyzer thereof |
| KR100481316B1 (en) * | 2002-04-11 | 2005-04-07 | 주식회사 팬지아이십일 | Determination Of Organic Compound By Metal Ion Coating Based Carbon Composite Electrode And It's Preparation Method |
-
2002
- 2002-09-11 KR KR1020020054826A patent/KR100623933B1/en active IP Right Grant
-
2003
- 2003-09-09 AU AU2003261001A patent/AU2003261001A1/en not_active Abandoned
- 2003-09-09 WO PCT/KR2003/001871 patent/WO2004025672A2/en not_active Application Discontinuation
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100776981B1 (en) * | 2006-06-23 | 2007-11-21 | 건국대학교 산학협력단 | Surface renewable iridium oxide composite hydrogen ion electrodes and their preparation methods |
| KR101202362B1 (en) * | 2010-03-02 | 2012-11-16 | 주식회사 과학기술분석센타 | Catalyst Including Pt-Ru of Working Electrode for COD Measuring Sensor and Manufacturing Process thereof |
| WO2015026104A1 (en) * | 2013-08-20 | 2015-02-26 | 주식회사 이지센싱 | Hydrogen ion electrode composed of composite material of nano iridium oxide and polymer resin and enabling surface regeneration, ph sensor using same, and method for manufacturing same |
| KR20150021454A (en) * | 2013-08-20 | 2015-03-02 | 주식회사 이지센싱 | Surface Renewable Hydrogen Ion Electrodes Made of Composite of Nano-Iridium Oxide and Polymer Resin, pH Sensor Using the Same and Preparation Method Thereof |
| US9810655B2 (en) | 2013-08-20 | 2017-11-07 | Ez Sensing Inc. | Hydrogen ion electrode composed of composite material of nano iridium oxide and polymer resin and enabling surface regeneration, pH sensor using same, and method for manufacturing same |
| KR101519359B1 (en) * | 2014-11-03 | 2015-05-13 | 길주형 | On-Line Multipurpose Chloride Analyzer |
Also Published As
| Publication number | Publication date |
|---|---|
| KR100623933B1 (en) | 2006-09-13 |
| AU2003261001A1 (en) | 2004-04-30 |
| AU2003261001A8 (en) | 2004-04-30 |
| WO2004025672A2 (en) | 2004-03-25 |
| WO2004025672A3 (en) | 2004-06-24 |
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