비점오염원 처리를 위한 동복천 인공습지의 시기별 및 부하량별 수처리 효율 평가

Evaluation of Wastewater Treatment Efficiency in Dongbokcheon Constructed Wetlands for Treating Non-point Source Pollution at Different Treatment Time and Wastewater Loading

비점오염원 저감을 위해 설치된 동복천 인공습지의 효율적인 관리 방안을 제시하기 위하여, 동복천 인공습지의 시기별 및 부하량별 수처리 효율평가를 실시하였다. 유입수의 BOD, SS, T-N 및 T-P 함량은 각각 $0.85{\sim}3.14mg\;L^{-1}$, $3.33{\sim}9.70mg\;L^{-1}$, $0.64{\sim}5.33mg\;L^{-1}$ 및 $0.03{\sim}0.10mg\;L^{-1}$ 범위이었으며, 연평균 처리효율은 BOD, SS, T-N 및 T-P가 각각 34%, 5%, 31% 및 13%로서 BOD와 T-N의 처리효율이 SS와 T-P 처리효율 보다 높았다. 인공습지 구성시스템별 오염물질 부하량에 따른 오염물질 처리량은 BOD에서 침강지 > 습지조 > 침전지, SS에서 침전지 > 습지조 > 침강지, T-N에서 침전지 > 침강지 > 습지조 순이었으며, T-P의 경우에는 침전지와 침강지에서는 큰 차이가 없었으나 습지조에서는 다른 시스템에 비해 높은 효율을 보였다.

To treat non-point source pollution in Dongbok lake, removal efficiencies of pollutants were investigated in Dongbokcheon constructed wetlands (CWs) at different treatment time and wastewater loading. The wetlands consisted of forebay, wetlands ($1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$, $5^{th}$, $6^{th}$, $7^{th}$, and $8^{th}$ wetlands) and sedimentation pond. The concentrations of BOD, SS, T-N, and T-P in inflow ranged $0.85{\sim}3.14mg\;L^{-1}$, $3.33{\sim}9.70mg\;L^{-1}$, $0.64{\sim}5.33mg\;L^{-1}$, and $0.03{\sim}0.10mg\;L^{-1}$ from April to October in 2008, respectively. The removal rates of BOD, SS, T-N, and T-P in Dongbokcheon CWs were 34%, 5%, 31%, and 13%, respectively. The removal rates of BOD and T-N were higher than those for SS and T-P. The amounts of pollutant removal in Dongbokcheon CWs were higher in the order of forebay > wetlands > sedimentation pond for BOD, sedimentation pond > wetlands > forebay for SS, sedimentation pond > forebay > wetlands for T-N. The amount of T-P removal in wetlands was higher than forebay and sedimentation pond.