Development of a COD(Chemical Oxygen Demand) Sensor Using an Electrode-surface Grinding Unit

전극표면 연마 유니트를 이용한 전기화학적 COD측정용 센서의 개발

  • Published : 2006.04.30

Abstract

An electrochemical COD(Chemical Oxygen Demand) sensor using an electrode-surface finding unit has been constructed. The electrolyzing(oxidizing) action of copper on the organic species was used as the basis of the COD measuring sensor. Using a simple three electrode cell, organic species which has been activated by the catalytic action of copper is oxidized at a working electrode, poised at a positive potential. A novel modification of the above method allowed for extended use of the electrode, in which the action of the electrode is regenerated by an electrode-surface grinding unit. When samples obtained from a wastewater treatment factory were measured, a linear correlation($r^2=0.93$) between the measured value(EOD) and $COD_{Mn}$ of the samples was observed. Overall results indicated that the electrochemical sensor with grinding unit could be applied for continuous measurements of COD in practical fields.

수질의 빠르고 정확한 COD(Chemical Oxygen Demand)의 측정을 위하여 전극표면 연마장치가 부착된 전기화학적 측정 센서시스템을 연구하였다. 수질 내 유기물에 대한 Cu의 산화작용이 COD 측정의 기본원리로 이용되었으며, 3전극계를 적용한 전기화학 셀을 COD 측정시스템에 적용하였다. 장시간의 COD 측정에 대비하여, Cu전극의 내구성과 안정성을 유지시키기 위해 회전되는 연마석을 이용한 자동연마장치를 부착하였다. 유기물을 함유한 인공시료 및 실제 현장시료를 이용하여 COD 변화에 대한 측정가능성을 실험하였고, $COD_{Mn}$ 수치와 COD 측정용 센서를 이용하여 측정한 Coulombic yield와의 사이에 높은 상관관계($r^2=0.93$)를 가지며 이 측정값을 EOD(electrochemical oxygen demand)로 표현할 수 있다는 것을 확인하였다. 이러한 측정 결과를 토대로 이 시스템이 폐수처리장 및 하수에 연속 COD 측정 장치로 적용할 수 있는 가능성이 있을 것으로 확인하였다.

Keywords

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