• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.441-444
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• 2016

본 연구에서는 유입수의 유입 방향을 달리 하였을 때 각 여재의 처리효율 차이점을 조사하고자 하였다. 실험재료는 제올라이트, 화산석, 발포 세라믹, 폴리에틸렌(Poly Ethylene) 4종의 여재이며 총 용적 31 L의 아크릴반응조에 각각의 여재를 충진하였고 각각 상향류 및 하향류의 흐름 방식을 적용하여 2차에 걸쳐 여과실험을 진행하였다. 제거효율은 유입수 대비 유출수의 농도 변화를 통하여 관찰하였고, 수질 측정은 SS, COD, T-N, T-P 네 항목으로 수질공정시험법에 의거하여 분석하였다. 실험 결과 제올라이트는 SS, COD, T-N항목에서 상향류를 적용한 여과에서 제거효율이 높은 경향을 보였다. 특히 T-N항목의 경우 상향류 조건에서 49.2%, 하향류 조건에서 34.4%의 제거효율을 나타내 흐름조건별 제거효율에 가장 큰 격차를 보였다. 화산석의 경우 SS, COD, T-N항목은 흐름방식에 따른 제거효율에 주목할 만한 차이를 드러내지 않았으나 예외적으로 T-P항목만 상향류 조건에서 24.2%, 하향류 조건에서 15.9%의 제거효율을 나타냄으로써 상향류 조건에서 8.3% 높은 제거효율을 얻었다. 발포 세라믹 여재는 하향류를 적용한 여과에서 제거효율이 우세한 경향을 보였으며 특히 COD 항목의 경우 상향류 조건에서보다 하향류 조건에서 제거효율이 7.5% 향상된 결과를 얻었다. 폴리에틸렌 여재는 전반적으로 유입 조건에 따른 경향성을 나타내지 않았으나 예외적으로 SS항목의 경우 하향류 조건에서보다 상향류 조건을 적용한 여과에서 7.9% 높은 제거효율을 얻었다.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.261-268
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• 2014

A sewage was treated using serially combined vertical(VFCW)and horizontal flow sand-filled reed constructed wetland(HFCW) with intermittent feeding. The sand had 1~3 mm diameter. The sewage entering the sewage treatment plant of Gyeonsang National University was fed into the reed constructed wetland bed for 10 minutes every 6 hours at the hydraulic load of $314L/m^2{\cdot}day$ based on the surface ares of the VFCW. In the VFCW effluent pH values were lower than those of the influent, whereas they were higher than those of the influent in the HFCW. DO values were increased in VFCW, but they were decreased in the HFCW. The OTR was $58.72gO_2/m^2{\cdot}day$ in the VFCW and $7.72gO_2/m^2{\cdot}day$ in the HFCW. Average removal efficiencies were SS 94.80%, BOD 90.77%, $COD_{Cr}$ 85.87%, $COD_{Mn}$ 87.72%, T-N 64.74%, $NH_4{^+}$-N 86.44%, T-P 87.70%. Nearly, half of T-N in the effluent was $NO_3{^-}$-N but the concentration of $NO_2{^-}$-N in the effluent was less than 0.64 mg/L.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.217-224
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• 2008

To obtain optimum configuration, depth and load of constructed wetlands(CWs) for treating of hydroponic waste solution(HWS) which was produced in greenhouses, the study was conducted with 4 kinds of combined systems such as Vertical flow(VF)-Horizontal flow(HF), VF-VF, HF-VF and HF-HF CWs. In four configurations of CWs, the treatment efficiency of pollutants from HWS under depth of HF and VF beds, HWS loading and HWSs were investigated. Removal rate of pollutants under different depth of VF and HF in 2-stage hybrid CWs was in the order of 50 cm < 70 cm regardless of CWs configuration. Removal rate of pollutants under HWS loading in 2-stage hybrid CWs was in the order of $150L\;m^{-2}\;day^{-1}{\fallingdotseq}300L\;m^{-2}\;day^{-1}\;>\;450L\;m^{-2}\;day^{-1}$. The optimum depth and HWS loading were 70 cm and $300L\;m^{-2}\;day^{-1}$ in four configurations of CWs, respectively. Using this optimum condition, for various HWSs (cucumber, paprika and strawberry HWS), removal rate of pollutants in HF-HF CWs was higher than that in HF-VF CWs. Optimum configuration of 2-stage hybrid CWs for treating hydroponic waste solution in greenhouses was found out to be HF-HF CWs. Therefore, under the optimum conditions, removal rate of BOD, COD, SS, T-N and T-P in HF-HF CWs were 84, 81, 84, 51 and 93%, respectively.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.258-265
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• 2009

To develop environmentally friendly constructed wetlands(CWs) for treating domestic sewage which was produced in farming and fishing village, the efficiency of water treatment at different ventilation systems in the vertical bed, depths of horizontal bed, and sewage loads was investigated. In the vertical bed, BOD and COD by duplex ventilation system were lower than those by single ventilation system. But T-N and T-P concentrations by both ventilation systems in the vertical bed were little different. In the horizontal bed, BOD, COD, T-N and T-P in 1.0 m and 1.3 m depths were little different. To reduce the CWs' area and to improve the pollutant removal efficiencies, the optimum depth of horizontal bed was 1.3 m. In single and duplex ventilation CWs, the removal rate of BOD, COD, SS, T-N and T-P decreased slightly with the sewage load increases. In same sewage load conditions, the removal rates of BOD, COD, SS, T-N and T-P by duplex ventilation CWs were higher than those by single ventilation CWs. In summary, to effectively treat domestic sewage from farming and fishing village, the optimum constructed wetlands would be the duplex ventilation CWs.

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.202-210
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• 2006

To develop small-scale sewage treatment apparatus for detached house of agricultural village, a small-scale sewage treatment apparatus by natural purification method that consisted of packaged form of aerobic, anoxic and anaerobic bed was constructed. The efficiency of sewage treatment according to the sewage treatment method, sewage loading, and the injection method of sewage were investigated for small-scale sewage treatment apparatus of packaged form of aerobic, anoxic and anaerobic bed. The removal rate of pollutants according to the sewage treatment method for small-scale sewage treatment apparatus was high in the order of aerobic-anoxic-anoxic bed < aerobic-anoxic-anaerobic bed. The optimum filter media in small-scale sewage treatment apparatus was a broken stone. The removal rate of pollutants according to sewage loading in small-scale sewage treatment apparatus was high in the order of $1,200L/m^2{\cdot}day\fallingdotseq900L/m^2{\cdot}day\fallingdotseq600L/m^2{\cdot}day$. The removal rate of pollutants according to injection method of sewage in small-scale sewage treatment apparatus was high in the order of continuous injection $\fallingdotseq$ intermittent injection. When loaded under the optimum conditions, removal rate of BOD, COD, SS, T-N and T-P were 99, 95, 99, 83 and 96%, respectively, through this 3-stepped small-scale treatment apparatus arrayed with the order of aerobic, anoxic and anaerobic bed.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.106-114
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• 1998

In this research, single-, two- and four-stage intermittently aerated activated sludge system were investigated for simultaneous removal of nitrogen and phosphorus with swine wastewater. For the comparison of removal efficiency, conventional activated sludge system was operated. Operational conditions of intermittently aerated activated sludge system were SRT 20day, HRT 24hr and aeration/nonaeration time 1hr/1hr, respectively. Nitrogen and phosphorus removal efficiency in Intermittently aerated activated sludge system was upgraded compare with conventional activated sludge system. In single-stage intermittently aerated activated sludge system, release-uptake of $PO_4^{3-}-P$ was observed very well but, phosphosrus removal in effluent was not effective. In single-stage intermittently aerated activated sludge system, release-uptake of $PO_4^{3-}-P$ in first reactor, was observed very well but, in following reactor, $PO_4^{3-}-P$ concentation showed almost no change. T-N removal efficiency in conventional activated sludge system, single-, two-, and four-stage intermittently aerated activated sludge system were 48, 87, 90.9 and 95.5%, respectively, and phosphorus removal efficiency were 48, 75, 97 and 95%, respectively. Intermittently aerated activated sludge system as a alternative processes of conventional system leads to meet satisfactory effleunt with only on/off aeration regulation and save energy for aeration.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.1
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• pp.79-91
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• 2005

Wetland systems are widely accepted natural water purification systems around the world in nonpoint sources pollution control. Constructed wetlands have become a popular technology for treating contaminated surface and wastewater. In this study, the field experiment to reduce nonpoint source pollution loadings from polluted stream waters using wetland system was performed from June 2002 to March 2004, including winter performance using four newly constructed wetlands. The Dangjin stream water flowing into Seokmun estuarine lake was pumped into wetlands, and inflow and hydraulic residence time of the system was $500m^{3}{\~}1500m^{3}/day\;and\;2{\~}5$ days respectively. After 3 years operation plant-coverage was about $80~90\%$ from zero at initial stage even with no plantation. Average water quality of the influent in growing season was BOD_{5}\;3.96mg/L$, TSS 22.98 mg/L, T-N 3.29 mg/L, T-P 0.30 mg/L. The average removal rate of four wetlands for $BOD_{5},\;TSS,\;T-N\;and\;T-P$ in growing season was $24\%$, $62\%$, $54\%$, and $51\%$, respectively. And average water quality of the influent in winter season was $BOD_{5}$ 4.92 mg/L, TSS 12.47 mg/L, T-N 5.54 mg/L, and T-P 0.32 mg/L, respectively. The average removal rate of four wetlands for them was $-21\%$. $23\%$, $33\%$, and $53\%$, respectively. The reason of higher BOD_{5} effluent concentration in winter season might be that low temperature restrained microorganism activity and a organic body from the withered plant and algae was flown out. Except the result of $BOD_{5}$, the effectiveness of water quality improvement in winter season was satisfactory for treating polluted stream waters, and $BOD_{5}$ variation was within the range of background concentration. Performance of the experimental system was compared with existing data base (NADB), and it was within the range of general system performance. Overall, the wetland system was found to be satisfactory for NPS control such as improvement of polluted stream water.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.575-578
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• 2003

Constructed wetlands have become a popular technology for treating contaminated surface and wastewater. In this study, the field experiment to reduce nonpoint source pollution from watershed runoff during rainy day using wetland and pond. TSS and T-N removal rate of wetland-pond system and pond-wetland system was 91% and 73%, 94% and 70%, respectively and values were same range. $BOD_5$ and T-P removal rate of pond-wetland system (38% and 78%) was higher than wetland-pond system (27% and 62%). overall, pond-wetland system is more useful than wetland-pond system to control NPS.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.7-16
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• 2006

The present study evaluated effect of temperature on removals of organic matter (C), nitrogen (N) and phosphorus (P) in Modified-Dephanox (M-Dephanox) process, which is hybrid system, comparing with those of Modified-Ludzack Ettinger (MLE) under the suspended-growth bacteria, as control. M-Dephanox process was more stable than MLE process in the removal of C, N, P, especially in nitrification, as the temperature was decreased from $25^{\circ}C$ to $16^{\circ}C$. As the temperature was decreased from $25^{\circ}C$ to $16^{\circ}C$, the removal efficiency of $NH_4{^+}-N$ of M-Dephanox process was decreased by 3.8%, but that of MLE process decreased by 25.7%. T-N removal efficiency of M-Dephanox was higher than MLE process by 27.1% and 26.9% at $25^{\circ}C$ and $16^{\circ}C$ of temperature, respectively.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.238-243
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• 2006

In order to improve the water quality of stream water, the facilities equipped with rope media filter have been examined as a part of national projects. This work may provide design and operating parameters from 2 years monitoring for 2 streams. Depending on the characteristics of streams, the flow rate into the facilities were shown different, where K stream was almost the same and D stream was less than 25% of design flow rate. Although the clogging of filter media was not observed during the operation, the removal of accumulated sludges was required for the stable operation. The removal efficiencies of BOD, SS, T-N and T-P for D stream were 60.5%, 80.1%, 25.2% and 36.2%, respectively. The most important factor for the construction of stream water purification facilities was recommended for the selection of proper sites.