인공습지를 이용한 하구담수호 유입하천수 수질개선 현장실험결과 분석

함종화,윤춘경,구원석,김형철,신현범,Ham, Jong-Hwa,Yoon, Chun-G.,Koo, Won-Seok,Kim, Hyung-Chul,Shin, Hyun-Bhum 한국농공학회 2004 한국농공학회논문집 Vol.46 No.5

Wetland system is widely accepted as one of natural water purification systems around the world for nonpoint sources pollution control. Constructed wetlands have become a popular technology for treating contaminated surface and waste water. 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. Four wetlands were used and the size of each one was 0.8ha. Water of Dangjin stream flowing into Seokmun estuarine reservoir was pumped into wetlands. Inflow and hydraulic residence time of the system was 500 $m^3$/day∼1,500 $m^3$/day, 2∼5 days, respectively. After 2 year operation, plant-coverage of the wetlauds was about 70% from bare soil surface at initial stage . Average water quality of the influent was $BOD_5$ 4.17 mg/L, TSS 18.45 mg/L, T-N 4.32 mg/L, and T-P 0.30 mg/L. The average removal rate of $BOD_5$, TSS, T-N and T-P during the study period was 5.6%, 46.6%, 45.7%, and 54.8%, respectively. Organic ($BOD_5$) removal rate was low and the reason might be low influent concentration. Wetland removal rate of T-P was about 10% higher than T-N. 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 adequate for treating polluted water stream with stable removal efficiency even during the winter period. Most of the nonpoint source pollutions from watershed are transported by streams or ditches, and they could be controled by constructed wetland system before entering the lake or reservoir.

불확실성을 고려한 통합유역모델링

함종화,윤춘경,다니엘 라욱스,Ham, Jong-Hwa,Yoon, Chun-Gyoung,Loucks, Daniel P. 한국농공학회 2007 한국농공학회논문집 Vol.49 No.4

The uncertainty in water quality model predictions is inevitably high due to natural stochasticity, model uncertainty, and parameter uncertainty. An integrated modeling system under uncertainty was described and demonstrated for use in watershed management and receiving-water quality prediction. A watershed model (HSPF), a receiving water quality model (WASP), and a wetland model (NPS-WET) were incorporated into an integrated modeling system (modified-BASINS) and applied to the Hwaseong Reservoir watershed. Reservoir water quality was predicted using the calibrated integrated modeling system, and the deterministic integrated modeling output was useful for estimating mean water quality given future watershed conditions and assessing the spatial distribution of pollutant loads. A Monte Carlo simulation was used to investigate the effect of various uncertainties on output prediction. Without pollution control measures in the watershed, the concentrations of total nitrogen (T-N) and total phosphorous (T-P) in the Hwaseong Reservoir, considering uncertainty, would be less than about 4.8 and 0.26 mg 4.8 and 0.26 mg $L^{-1}$, respectively, with 95% confidence. The effects of two watershed management practices, a wastewater treatment plant (WWTP) and a constructed wetland (WETLAND), were evaluated. The combined scenario (WWTP + WETLAND) was the most effective at improving reservoir water quality, bringing concentrations of T-N and T-P in the Hwaseong Reservoir to less than 3.54 and 0.15 mg ${L^{-1}$, 26.7 and 42.9% improvements, respectively, with 95% confidence. Overall, the Monte Carlo simulation in the integrated modeling system was practical for estimating uncertainty and reliable in water quality prediction. The approach described here may allow decisions to be made based on probability and level of risk, and its application is recommended.

농업용 저수지 수질모델 (ARSIM-rev) 개발 및 적용

함종화,김동환,김형중,김미옥,Haam, Jong Hwa,Kim, Dong Hwan,Kim, Hyung Joong,Kim, Mi-Ock 한국농공학회 2012 한국농공학회논문집 Vol.54 No.6

Agricultural reservoir water quality simulation model (ARSIM-rev) was developed in this study for water quality simulation of a small and shallow agricultural reservoir with limited observed water quality data. Developed ARSIM-rev is a zero-dimensional water quality model because of little spatial differences in water quality between stations in a small and shallow agricultural reservoir. ARSIM-rev used same water quality reaction equations with WASP except for several equations, and daily based input parameters such as settling rate, release rate from sediment, and light extinction coefficient changed yearly based input parameters in ARSIM-rev. A number of pre- and post-processors were developed such as auto calibration and scenario analysis for ARSIM-rev. CE-QUAL-W2, WASP, and developed ARSIM-rev were applied to Mansu agricultural reservoir to evaluate model performance, and ARSIM-rev demonstrated similar model performance with CE-QUAL-W2 and WASP when low number of observed data was used for agricultural reservoir water quality simulation. Overall, developed ARSIM-rev was feasible for water quality simulation in a small and shallow agricultural reservoir with limited observed water quality data, and it can simulate agricultural reservoir water quality precisely enough like common water quality model such as CE-QUAL-W2 and WASP within a limited time.

물리적 설계인자가 인공습지의 처리효율에 미치는 영향

함종화,윤춘경,구원석,김형철,신현범,Ham Jong-Hwa,Yoon Chun G.,Koo Won-Seok,Kim Hyung-Chul,Shin Hyum-Bhum 한국농공학회 2005 한국농공학회논문집 Vol.47 No.5

The field scale experiment was performed to examine the effect of physical design parameters on the constructed wetland performance and recommend the feasible design of constructed wetland in Korean polder areas. Four sets (each set of 0.85 ha) of wetland (0.8 ha) and pond (0.08 ha) systems were used. Two different wetland systems, a wetland-pond system and a pond-wetland system, were studied to examine the effect of wetland and pond configuration. And two different length-to-width ratios were used, 2: 1 and 0.8: 1, to examine the effect of aspect ratio. A pond-wetland system was more preferable than a wetland-pond system, and also requires a smaller area than a wetland-pond system or a wetland system to reduce T-P. There was no difference in effluent concentration between the 2:1 system and the 0.8:1 system. Although the linear velocity of the 2:1 aspect was higher than the 0.8:1 aspect, resuspension was not a factor in this study due to a very low linear velocity. From this study and other literature review, it was found that design method of paddy rice field could be applied and expanded to the design of constructed wetland in Korea. Further investigation for the detailed design parameters of constructed wetland needs be continued for design method of paddy rice to be applied in full scale.

자유수면형 인공습지에 의한 저농도 고유량의 하천수질개선 효과 분석

함종화,윤춘경,구원석,김형철,신현범,Ham, Jong-Hwa,Yoon, Chun G.,Koo, Won-Seck,Kim, Hyung-Chul,Shin, Hyum-Bhum 한국농공학회 2005 한국농공학회논문집 Vol.47 No.1

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.

자유수면형 인공습지에서 식물식재 유무가 처리효율에 미치는 영향

함종화,김형중,김동환,홍대벽,Ham, Jong-Hwa,Kim, Hyung-Joong,Kim, Dong-Hwan,Hong, Dae-Byuk 한국농공학회 2011 한국농공학회논문집 Vol.53 No.6

Three different types of wetlands (unplanted wetland, reed planted wetland, cattail planted wetland) were constructed at the mouth of Seokmoon reservoir with 910 $m^2$ each to examine the effects of wetland plant on pollutant removal rate in constructed wetland, and operated for 9 years (2002~2010). Water depth of the wetland was maintained at 0.3~0.5 m, flow rate was about 40~200 $m^3$/day, and retention time was managed at about 1~5 days. There was no difference in removal rate of SS, TN, and TP between reed wetland and cattail wetland. Removal rate of SS and TN in planted wetland with reed and cattail were higher than unplanted wetland, whereas removal rate of TP in unplanted wetland was higher then planted wetland. The monthly variation of removal rate in planted wetlands was high compared with unplanted wetland. From the long term monitoring results, SS and TN removal rates of period3 (2008~2010) were higher than period1 (2002~2004) in planted wetland, whereas TP removal rate was decreased as time goes on. Overall, pollutant removal rate in constructed wetland was more influenced by existence of plants than by plant species. Although constructed wetland is operated long term period, SS, TN, and TP removal rate (SS 90 %, TN 60 %, TP 40 %) can be maintained high values.

여재를 이용한 인공습지 유출수 추가처리

함종화,김형중,김영경 한국습지학회 2009 한국습지학회지 Vol.11 No.2

본 연구는 인공습지 유출수를 추가처리하기 위해 다양한 재료를 이용한 추가처리시설의 적용가능성을 분석하였다. 석문담수호 유입부에 설치된 인공습지 중 무식재구, 갈대식재구, 부들식재구의 하단 배수로(폭 0.3m, 수심 0.35 m)에 각각 제강슬래그, 활성탄, 굴폐각을 이용해 1.0 m 길이로 추가처리시설을 설치하였으며, 각 후처리시설별로 유입유량을 다르게 적용하였다(제강슬래그 63 m3/day; 활성탄 19 m3/day; 굴폐각 81 m3/day). 제강슬래그, 활성탄, 굴폐각의 COD 처리율은 각각 6 %, 24 %, 1 %로 나타났으며, 제거량은 32, 30, 5 g/day로 나타나, 모든 추가처리시설에서 유기물제거에 효과적인 것으로 나타났다. T-N과 T-P의 제거효율은 활성탄에서 24 %와 4 %로 효과적이었으나, 제강슬래그 및 굴폐각에서는 효과가 없는 것으로 나타났다. 이상의 결과로부터 추가처리시설을 상대적으로 영양물질제거에 효과적인 인공습지와 연계하여 운영할 경우 영양물질 및 유기물을 효과적으로 제거할 수 있을 것으로 판단된다. Further treatment facility using various filter materials was evaluated to treat effluent of constructed wetland. Further treatment facility was installed with 1m length in outlet of 3 constructed wetland (unplanted constructed; reed bed constructed wetland; cattail bed constructed wetland) using 3 filter materials (slag, activated carbon, oyster shell). Flow rate of three further treatment facility was 63 m3/day (slag), 19 m3/day (activated carbon), and 81 m 3/day (Oyster shell). COD removal rate of slag, activated carbon, and oyster shell was 6 %, 24 %, 1 %, and removal mass was 32 g/day, 30 g/day, and 5 g/day, respectively. All of further treatment facility was effective to removal organic materials. T-N and T-P removal rate of activated carbon was 24 % and 4 %, and slag and oyster shell was not effective to remove T-N and T-P. Overall, further treatment facility was effective to remove organic mater, constructed wetland combined with further treatment facility can remove nutrient and organic matters effectively.

연못을 이용한 동절기 인공습지 오수처리수의 추가 처리

함종화,윤춘경,전지홍,김민희 한국농공학회 2002 한국농공학회논문집 Vol.44 No.4

Pilot study was performed to examine the feasibility of the pond system for further polishing of treatment wetland effluent from December 2000 to June 2001. The wetland system used for the experiment was highly effective to treat the sewage during the growing season, but it was less effective and its effluent was still high to discharge to the receiving water body. Therefore, the wetland effluent may need further treatment to prevent water quality degradation. Pond system could be used to hold and further polish the wetland effluent during the winter season and its feasibility was evaluated in this study. Additional water quality improvement was apparent in the pond system during winter season, and the pond effluent could be good enough to meet the effluent water quality standards if it is properly managed. Timing of the pond effluent discharge appears to be critical for pond system management because it is a closed system and whole water quality constituents are affected by physical, chemical, and biological pond environments. Once algae started to grow in mid-April, constituents in the pond water column interact each other actively and its control becomes more complicated. Therefore, upper layer of the pond water column which is clearer than the lower layer may need be discharged in March right after ice cover melted. In the experiment, water quality of the upper water column was markedly clear in March than any other times probably because of freezing-thawing effect. The remaining lower water column could be further treated by natural purification as temperature goes up or diluted with better quality of wetland effluent for appropriate water uses. This study demonstrated the feasibility of pond system for subsequent management of wetland effluent during the winter season, however, more study is needed for field application. 본 연구에서는 동절기 고농도의 습지처리수를 추가처리하기 위하여 연못시스템을 적용하여, 인공습지 및 연못시스템의 농도변화, 연못시스템 바닥에 있는 모래의 화학적 특성변화 및 인공습지와 연못시스템의 연계적용에 대해 분석하였으며, 그 결과를 요약하면 다음과 같다.1. 인공습지를 이용해 정화조 오수를 처리한 결과 동절기에도 일정한 처리율을 얻을 수 있었지만, 동절기 습지처리수를 하천으로 직접방류하기에는 높은 농도를 나타냈기 때문에 추가적인 처리가 요구되었다.2. 연못시스템에 오수 및 습지처리수를 채우고 실험한 결과, 각 항목별로 겨울동안 상당한 수질개선효과를 얻을 수 있었으며, 4월 이후에는 조류가 크게 번성하면서 대부분의 수질항목에서 다시 농도가 상승하기 시작하였다.3. 연못시스템의 바닥에 있는 모래를 화학분석한 결과 OM, TN, TP, AV. P2O5 항목에서 유기물질, 영양물질 및 조류의 침전에 의해 연못시스템 적용 후에 농도가 높아진 것으로 나타났다. 따라서, 연못시스템을 장기적으로 운영하였을 경우 침전 및 재용출 기작에 대한 추가적인 연구가 요구된다.4. 인공습지와 연못시스템을 연계적용하여 동절기 고농도의 습지처리수를 추가 처리할 경우, 3월중에 상층부를 방류하는 것이 수질관리에 유리한 것으로 나타났다. 3월초에 상층부만 방류할 경우의 제거율은 BOD5, SS, TP 및 TN이 각각 84.4%, 81.5%, 81.1% 및 76.3%로 나타나서 동절기 습지시스템의 유출수를 추가 처리하는데 연못시스템이 효과적인 대안으로 생각된다.5. 본 연구는 12월에 습지처리수를 저류한 후 수질변화를 관찰한 batch test였으나, 동절기 동안 습지처리수가 연못시스템으로 계속 유입(Plug-flow)될 경우의 수질변화에 대한 추가 연구가 필요하다.

대규모 인공습지의 초기 운영 결과

함종화 ( Jonghwa Ham ),이태호 ( Taeho Lee ) 한국농공학회 2014 한국농공학회 학술대회초록집 Vol.2014 No.-

화옹지구 간척지 개발사업은 공업화, 도시화로 인하여 감소되는 농지를 대체하고 수자원 확보, 육운개선, 도시민의 휴식 공간 제공 등의 목적으로 계획되었다. 화옹지구 간척지 개발사업의 결과 4,482ha의 간척지, 1,730ha의 담수호가 개발되어 5,440만톤의 수자원이 확보될 것이다. 그리나, 사업 완료 후 조성되는 1,730ha의 담수호 수질이 농업용수 수질기준을 초과하지 않도록 하기 위해 2002년에 관련기관 합동으로 수질오염방지 종합대책을 수립·확정하였다. 유역대책으로는 공공하수처리장 2개소, 마을하수도 15개소, 축산폐수처리용 저장액비 탱크, 가축분뇨 공공처리장 및 비점오염원 저감시설을 설치하였으며, 호내대책으로는 인공습지, 침강지 및 수초저류지를 설치하였다. 화성호로 유입되는 비점오염물질을 제거하기 위해 화성호로 유입되는 3개의 유입하천 말단에 각각 인공습지 (남양, 주곡, 매향)를 계획하여 2010년부터 2013년까지 설치하였다. 본 연구에서는 화성호 간척지에 조성된 3개의 인공습지 중 안정적으로 운영 중인 남양습지에서 조사한 수질결과를 분석하였다. 각각의 인공습지 앞에 입자성 물질을 침전시키기 위해 추가로 침강지를 조성하였으며, 인공습지의 면적이 넓고 정상 운영 전까지 시간이 충분하여 습지식물을 별도로 식재하지 않고 자연발아하여 정착하도록 하였다. 2014년 6월부터 정상운영 계획 중에 있는 남양인공습지는 시설점검 및 개략적인 수질개선효율을 조사하기 위해 2012년 5월부터 9월까지 임시 운영하였다. 현장에서 수온, pH, DO, EC를 조사하고, 채취한 시료는 수질오염공정시험법으로 COD, T-N, T-P, Chl-a를 분석하였다. 식생피도가 10% 이하로 습지식물이 거의 자생하지 않고 있었던 2012년 5월부터 9월까지 임시 운영한 결과 남양습지의 COD, T-N, T-P, Chl-a의 유입수 농도는 각각 12.2 mg/L, 2.14 mg/L, 0.114 mg/L, 53.1mg/㎥였으나, 인공습지를 통과하면서 각각 12.3%, 27.0%, 16.7%, 53.5% 처리되어 유출수의 농도는 10.7 mg/L, 1.56 mg/L, 0.095 mg/L, 24.7 mg/㎥로 나타났다. 평균 식생피도가 약 30%를 나타내었던 2014년 6월부터 8월까지 남양습지를 운영한 결과 COD, T-N, T-P, Chl-a의 처리효율은 각각 5.0%, 40.0%, 39.8%, 64.3%로 나타나 상대적으로 영양물질 및 Chl-a의 처리효율이 높게 나타났다. 위와 같이 화옹지구 간척지 개발사업 완료 후 조성되는 화성호의 수질을 농업용수 수질기준 이하로 유지하기 위해 모델링을 통해 적정 규모의 인공습지를 계획·설치하고, 인공습지를 운영한 결과 초기에 낮은 식생피도를 나타내고 있음에도 불구하고 영양물질에 대해 높은 처리율을 나타내었다. 2014년 6월부터 습지가 정상 운영되어 습지식물이 자생하게 되면 3개의 대규모 인공습지를 통해 화성호로 유입되는 오염물질이 상당량 제거되어 화성호의 수질이 농업용수 수질기준 이하로 유지될 수 있는 것으로 판단된다. 향후 조성된 인공습지의 수처리 효율 모니터링을 통해 수처리 효율을 검증하고 최상의 수처리 효율을 얻기 위한 최적의 인공습지 운영방안을 수립할 계획이다.

농촌유역의 수질예측을 위한 BASINS의 적용 - HSPF모형을 중심으로 -

함종화 ( Ham Jong Hwa ),윤춘경 ( Yoon Chun Gyeong ) 한국농공학회 2001 한국농공학회 학술대회초록집 Vol.2001 No.-

For the water quality management of stream and lake, it is important to estimate and control nonpoint source loading to meet the water quality standard. So, integrated watershed management is required. BASINS is a multipurpose environmental analysis system for use by regional, state, and local agencies in performing watershed and water quality based studies. BASINS was developed by the USEP A to facilitate examination of environmental information, to support analysis of environmental systems and to provide a framework for examining management alternatives. BASINS contains HSPF which is one of the watershed runoff model. By using HSPF, nonpoint source loading from upper stream watershed was estimated. As a result, the simulated runoff was in a good agreement with the observed data and indicated reasonable applicability for whole watershed.