Performance of an electrochemical COD (chemical oxygen demand) sensor with an electrode-surface grinding unit.
An electrochemical COD (chemical oxygen demand) sensor using an electrode-surface grinding unit was investigated. The electrolyzing (oxidizing) action of copper on an organic species was used as the basis of the COD measuring sensor. Using a simple three-electrode cell and a surface grinding unit, the organic species is activated by the catalytic action of copper and oxidized at a working electrode, poised at a positive potential. When synthetic wastewater was fed into the system, the measured Coulombic yields were found to be dependent on the COD of the synthetic wastewater. A linear correlation between the Coulombic yields and the COD of the synthetic wastewater was established (10-1000 mg L(-1)) when the electrode-surface grinding procedure was activated briefly at 8 h intervals. When various kinds of wastewater samples obtained from various sewage treatment plants were measured, linear correlations (r(2)> or = 0.92) between the measured EOD (electrochemical oxygen demand) value and COD of the samples were observed. At a practical wastewater treatment plant, the measurement system was successfully operated with high accuracy and good stability over 3 months. These experimental results show that the application of the measurement system would be a rapid and practical method for the determination of COD in water industries.
Geun Jeong
Bong
B
Department of Microbial Engineering, Konkuk University, Gwangjin-Gu, Seoul 143-701, Korea.
Min Yoon
Seok
S
Ho Choi
Chang
C
Koang Kwon
Kil
K
Sik Hyun
Moon
M
Heui Yi
Dong
D
Soo Park
Hyung
H
Kim
Mia
M
Joo Kim
Hyung
H
D004563:Electrochemistry; D004566:Electrodes; D009862:Online Systems; D010100:Oxygen / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods
D010100:Oxygen