Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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Effect of electrode coating and applied voltage of pulsed electric fields (PEF) on sludge solubilization

펄스전기장 (Pulsed Electric Fields)의 전극 코팅과 인가 전압에 따른 슬러지의 가용화 효과

  • Um, Se-Eun (Department of Nanobiotronics, Hoseo University) ;
  • Chang, In-Soung (Department of Environmental Engineering, Hoseo University)
  • 엄세은 (호서대학교 나노바이오트로닉스학과) ;
  • 장인성 (호서대학교 환경공학과)
  • Received : 2018.07.25
  • Accepted : 2018.10.05
  • Published : 2018.10.31
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Abstract

Alternative technologies for sludge treatment and disposal need to be developed urgently because the amount of produced production has increased continuously. In this study, Pulsed Electric Fields (PEF) technique was applied for sludge solubilization and the performance was evaluated. The PEF equipped with electrodes coated by epoxy resin and teflon was inducted to the activated sludge suspension, and the effect of the coating materials on the solubilization was determined. In addition, the effect of the applied voltage on the solubilization yield was investigated as the applied voltage was increased from 6 to 12 and 15 kV. Sludge solubilization was not observed when the epoxy-coated electrode was used for PEF induction regardless of the applied voltage. However, sludge solubilization occurred when 12 and 15 kV were applied to the teflon-coated electrodes. The MLSS decreased to 9%, and the soluble-COD increased to 496% when the applied voltage was 15 kV. But sludge solubilization did not happen under 6 kV condition. The corona discharge was observed at applied voltages of 12 and 15 kV, (Ed- sorry but I cannot understand the following highlight) but if 6 kV, strongly indicating that the corona discharge make the sludge solubilized, which suggests that the critical voltage for sludge solubilization lies between 6 and 12 kV. Consequently, proper selection of electrode-coating materials and the applied voltage of PEF could lead to sludge solubilization by corona discharge.

하 폐수 슬러지 발생량의 꾸준한 증가로 인해 폐 슬러지의 효율적인 처리 기술개발이 요구되고 있다. 본 연구에서는 PEF (Pulsed Electric Fields) 기술을 활용하여 슬러지의 가용화를 통한 감량화 가능성을 평가하였다. PEF에 사용되는 스테인레스 재질의 전극에 테프론과 에폭시로 코팅한 후 활성슬러지 혼합액에 전계 펄스를 인가하여 전극 코팅에 따른 가용화 효율을 평가하였다. 또한 인가된 전압의 세기를 6, 12, 15 kV로 변화시켜 가며 가용화 정도를 평가하였다. 에폭시 코팅 전극에서는 MLSS, 용존성-COD, -TN, -TP를 분석한 결과 슬러지의 가용화가 발생하지 않은 것으로 나타났다. 그러나 테프론으로 코팅한 전극에서는 MLSS는 최대 9 % 감소하였고 MLVSS 역시 최대 10 % 감소하였다. 또한 용존성-COD는 최대 496 % 증가하였다. 인가전압 6 kV 하에서는 가용화가 거의 발생하지 않았으나, 12 kV와 15 kV의 전압에서는 슬러지 가용화가 발생한 것으로 나타났다. 또한 슬러지 가용화가 발생한 12 kV와 15 kV의 전압에서는 코로나가 발생한 것으로 보아 슬러지 가용화는 코로나에 의해 유도되었으며, 코로나가 발생하는 임계전압이 존재하는 것으로 판단되었다. 결론적으로 PEF의 인가전압과 적절한 코팅제를 선택하여 코로나 발생을 제어함으로써 슬러지의 가용화를 유도할 수 있음을 확인하였다.

Keywords

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