Journal of Wetlands Research (한국습지학회지)

Korean Wetlands Society (한국습지학회)
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Simulation of Various Baffle Types in a Constructed Wetland Sedimentation Tank using CFD

CFD를 이용한 Hybrid 인공습지의 초기침강지 저류판 구조 모의

  • Noh, Taegyun (Department of Civil and Environmental Engineering, Kongju National University) ;
  • Jeon, Jechan (Department of Civil and Environmental Engineering, Kongju National University) ;
  • Kim, Lee-Hyung (Department of Civil and Environmental Engineering, Kongju National University)
  • 노태균 (공주대학교 건설환경공학과) ;
  • 전제찬 (공주대학교 건설환경공학과) ;
  • 김이형 (공주대학교 건설환경공학과)
  • Received : 2016.07.28
  • Accepted : 2016.08.29
  • Published : 2016.08.31
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Abstract

Constructed wetlands are widely applied in urban and rural areas for various purposes such as pollutants reduction, acquisition of eco-spaces and habitats, flooding reduction, acquisition of water resources and environmental education. Since the design of constructed wetlands utilizes ecosystems, special consideration must be given to ecological mechanisms, environmental mechanisms and hydrological mechanisms. To ensure the sustainable functionality of constructed wetlands, it is necessary to achieve stable flow rate and velocity, and remove sediments to ensure sufficient space for detention. To enhance the efficiency of constructed wetland sedimentation basins, this study determined the optimal position for baffle installation, and applied Computational Fluid Dynamics (CFD) to the cross-sectional design of wetlands. CFD analysis revealed that the decrease in flow velocity with baffle installation enhanced the efficiency of sedimentation of particulate matters. Vertical baffles had higher sedimentation efficiency than those with an inclined angle. When vertical baffles were installed in the sedimentation basin of a hybrid constructed wetland to reduce non-point source pollutants in urban areas, the average flow velocity within the basin decreased by 10~30%, while the sedimentation efficiency improved by 1.3~1.5 times. The application of CFD to constructed wetlands is expected to improve the cost efficiency of designing hybrid constructed wetlands with high removal efficiency.

인공습지는 오염물질 저감기능을 포함하는 여러 가지 생태서비스 기능 때문에 다양하게 적용되고 있다. 그러나 인공습지에 많은 입자상 물질이 유입하게 되면 유지관리의 어려움과 기능의 저하를 초래한다. 따라서 본 연구는 인공습지 내입자상 물질의 제거효율 향상을 위한 침강지내 최적 baffle 설치방안을 도출하고자 수행되었다. 최적 저류판 설치방안은 침강지내 유체와 입자의 흐름을 해석함으로써 도출가능하며, 이를 위해 전산유체역학(Computational Fluid Dynamics, CFD) 이론을 활용하였다. 연구결과는 baffle이 유속을 저하시키고 입자상 물질의 침강효율을 증가시키는 것으로 나타났으며, 경사각을 가진 저류판보다는 수직 저류판이 효과적인 것으로 나타났다. 이러한 연구결과를 활용하여 공공지역 비점오염저감시설로 설치된 소규모 하이브리드 인공습지의 침강지 효율개선 방안을 도출하였다. 수직각을 이용한 저류판을 설치할 경우 침강효율이 1.2~1.3배 정도 증가하는 것으로 나타났다. 이러한 침강지 내 저류판의 설치에 따른 결과는 인공습지의 전반적인 저감 효율을 증가시킬 뿐만 아니라 유지관리 빈도를 줄임으로써 비용효율적 인공습지 설계에 기여할 것으로 평가된다.

Keywords

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