3D 복극충진전기분해를 이용한 원전 ETA에 의해 유발된 폐수 내 COD 및 T-N 제거

Abstract

Ethanolamine (ETA) is mainly used to prevent corrosion of pipe in secondary cooling system of nuclear power plant. Condensed ETA in wastewater could increase COD and T-N when it was emitted to natural water system. Compared to conventional treatments, electrochemical oxidation process using packed bed bipolar electrodes was adopted to treat COD and T-N. According to arrangement of feeder electrode, single packed bed bipolar electrode reactor and multi-paired packed bed bipolar reactor were developed and conventional zero-valent iron (ZVI) was selected as conducting bipolar electrode. Bipolar electrodes were coordinated three-dimensionally in the reactor. The experimental results showed that COD and T-N was little removed in unit system at different pH condition (pH 8 and 11) on 100V. However, in multi-paired system that applied 600V, COD was eliminated 80.85% (anode-cathode-anode, A-C-A) and 85.11% (cathode-anode-cathode, C-A-C), respectively. T-N was also removed 96.88% (A-C-A) and 90.63% (C-A-C), simultaneously. Current efficiency was estimated both single and multi-paired system. At unit bipolar packed bed reactor, current efficiency was almost zero, however in multi-paired system, current efficiency was 300~500% at A-C-A and 250~350% at C-A-C. Current efficiency was over 100% hence it was confirmed that this system is more effective than conventional electrochemical oxidation system.