Evaluation of the Oxygen Transfer Parameters (α and F) of a Coarse Bubble Aeration System by Off-gas Column Test

Off-gas Column Test를 이용한 하수처리장 심층포기시스템의 산소전달 매개변수(α와 F)의 산정

  • Kim, Chul Woong (School of Civil and Environmental Engineering, Yonsei University) ;
  • Lee, Se Ho (School of Civil and Environmental Engineering, Yonsei University) ;
  • Shin, Dong Rok (Environmental Dept., EcoOne Corp.) ;
  • Lee, Ji Yong (School of Civil and Environmental Engineering, Yonsei University) ;
  • Park, Jae Han (School of Civil and Environmental Engineering, Yonsei University) ;
  • Ahn, Yoon Hee (School of Civil and Environmental Engineering, Yonsei University) ;
  • Ko, Kwang Baik (School of Civil and Environmental Engineering, Yonsei University)
  • 김철웅 (연세대학교 공과대학 토목공학과 환경공학연구실) ;
  • 임세호 (연세대학교 공과대학 토목공학과 환경공학연구실) ;
  • 신동록 ((주) EcoOne Corp. 환경사업본부) ;
  • 이지영 (연세대학교 공과대학 토목공학과 환경공학연구실) ;
  • 박재한 (연세대학교 공과대학 토목공학과 환경공학연구실) ;
  • 안윤희 (연세대학교 공과대학 토목공학과 환경공학연구실) ;
  • 고광백 (연세대학교 공과대학 토목공학과 환경공학연구실)
  • Received : 2006.01.17
  • Accepted : 2006.10.20
  • Published : 2006.11.30

Abstract

Aeration by using diffusers usually requires approximately 50~90% of the total electricity needed to operate WWTP (WasteWater Treatment Plant)s. Accurate evaluation of the oxygen transfer efficiency for an aeration system, and recommendation of a better alternative may help saving WWTP operational costs. Appropriate techniques and methods to achieve this purpose have not been introduced in Korea. In this study, in-process analysis was performed for a coarse bubble aeration system by the off-gas method to evaluate its applicability in Korea. To accomplish this analysis, an off-gas test, unsteady-state clean water test and steady-state off-gas column test was conducted and comparisons to other aeration systems were made. The ${\alpha}$ and the F estimated from the results of the unsteady-state clean water test and the steady-state off-gas column test were 0.61 and 0.90 respectively in a coarse bubble aeration system. The comparison of P.E tube diffusers laid out single spiral roll and ceramic dome diffusers laid out full floor coverage showed that the oxygen transfer efficiency of the coarse bubble aeration system was less than or similar to other aeration systems. But, airflow rates per unit area were 4~5 times greater than other aeration systems. In regards to the oxygen transfer efficiency for airflow rates per unit area, a retrofit to higher efficiency diffusers was urgently needed. This study showed proved that off-gas methods can apply to evaluate diffuser performances to estimate operating factors and to compare other aeration systems in Korea.

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