• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.220-220
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• 2020

영산강수계는 상류에 4개의 농업용 댐이 위치하여 환경대응용수 확보 및 하천유지유량이 절대적으로 부족하고, 갈수기 하천 유량의 약 67 %가 광주 제 1, 2 하수처리장 방류수가 차지하고 있어 하천의 수질과 수생태계를 위협하고 있다. 이에 최근에는 오염된 하천의 건강성을 회복하기 위한 방법으로 수생태계의 정화능력을 활용한 인공습지가 각광받고 있다. 영산강 유역에서도 자연의 정화능력을 활용하여 하천 오염원을 저감시키기 위한 사업의 일환으로 2016년 광주 제 2 하수처리장 방류구에 서창오미공원 습지를 조성하였다. 이 습지는 유입량이 적어 정상적 기능이 어려운 기존 습지를 재조성한 것으로 하수처리장 방류수 약 5만 ㎥/day을 습지로 유입시켜 수질정화용 식재식물을 이용하여 하수처리장 방류수 수질을 개선한 사업이다. 2016~2017년 모니터링 결과, 습지 유입 전·후 BOD는 평균 33.5 %, 최대 73.1 % 저감 되었으며, T-P 또한 평균 59.3 %, 최대 91.6 % 저감 되었다. 그러나 습지는 운영기간 경과 시 퇴적물 축적, 고사체로 인한 T-P 용출 등으로 인하여 처리수의 수질이 더 악화될 우려가 있기 때문에 습지 조성 후 지속적인 유지관리와 모니터링이 필요하다. 그 예로 하수처리장 방류수와 비점오염원 처리를 위해 주암호에 조성된 인공습지의 경우, 2001년 준공 후 지속적인 관리 및 모니터링을 통하여 약 17년이 지난 2018년에도 BOD 49.3 % T-N 65.1 %, T-P 19.2 % 로 저감되어 오염원 및 영양염류 제거에 큰 효과가 있는 것으로 나타났다. 따라서 본 조사에서는 서창오미공원과 주암호 인공습지 운영 결과를 토대로 습지 모니터링의 중요성과 적정 운영 방안을 제시하고자 하며, 영산강 하천의 점·비점오염원 저감을 위한 신규 인공습지 조성 사업에 기초자료로 활용하고자 한다.

• Journal of the Korean GEO-environmental Society
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• v.10 no.1
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• pp.43-48
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• 2009

This study was performed to investigate the characteristics of nutrient removal by Sequencing Batch Reactor (SBR) system, which could achieve high removal efficiencies of nitrogen and phosphorus and make it possible convenient management and operation. In this study, dissolved oxygen (DO), chemical oxygen demand (COD), nitrogen, and phosphorus in SBR system were examined by variation of anoxic-oxic phase repetition in order to optimize an operational method. The 1~4 times of anoxic-oxic phases (Run 1~4) were repeated during 1 cycle operation period. As the repetition frequency increased, it was more difficult to maintain DO condition enough for denitrification. The SBR system showed high COD removal efficiency more than 91% regardless of operational condition. About 68% of nitrogen removal rate was obtained in conditions of 2 or 3 times repetition of anoxic phases, in which NOx-N among discharged total nitrogen account for more than 99%. Approximately 40% of phosphorus was eliminated in the conditions of 1~3 times of anoxic phase repetition.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.3-3
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• 2021

하천의 식생은 생태서식처 제공, 강턱이나 하안 경사의 안정, 영양염류나 오염물 차단에 의한 수질 개선 등의 다양한 생태서비스를 제공하는 반면, 과도하고 편중된 식생 분포로 인해 흐름저항이 증가하고 이로 인한 홍수위 상승과 홍수피해 위험이 가중될 수 있다. 기후변화 영향과 토지이용 변화에 따른 수리수문 특성 변화와 유역으로부터 영양염류의 유입은 하천내 식생이 과도하게 퍼지는 직접적인 원인이 될 수 있다. 과도한 식생분포로 인한 흐름저항과 홍수위 상승을 평가하기 위해 식생하도의 흐름저항과 관련된 매개변수의 다양성과 복잡성에 따른 해석상의 한계에도 불구하고 이에 대한 이론적 해석과 수학모형의 개발, 실험실 수로와 하천현장조사, 수치모형을 이용한 예측 등의 다양한 연구가 수행되고 있다. 본 연구에서는 소규모 실험실 수로에서 단순화된 식생 구조와 배열이 적용되는 한계성과 상류에서 유입되는 유량과 유속 등의 수리조건을 통제할 수 없는 현장실험의 한계성을 보완하고자 목본류 형태의 식생패치를 실규모 하천실험 수로에 조성하여 통제된 수리조건에서의 식생하도의 구간 흐름저항을 추정하기 위한 계측 실험을 수행하였다. 실규모 실험에서는 피에조미터 형식의 정밀 압력식 센서를 이용하여 수위와 수면경사를 계측하였으며, 실험구간의 접근 수로에서 ADCP(Acoustic Doppler Current Profiler)를 이용하여 유입 유량에 대한 정보를 수집하였다. 전체 수로 길이 약 600 m, 하폭 11 m, 깊이 2 m 규모의 실규모 하도 일부 80 m 완경사 구간에 식생패치를 설치하고 구간 수면경사를 실측함으로써 식생하도의 흐름저항을 직접 산정하였다. 이러한 실규모 식생하도의 실험을 통해 식생패치의 밀도, 횡적 차단면적, 구간 차단부피, 목본 식생의 물리적 특성, 식생패치의 배열 등의 다양한 식생분포 조건에 따른 수리조건별 흐름저항 값의 변화를 분석할 수 있다. 식생하도에 대한 정확한 흐름저항 추정과 홍수위 변화에 대한 해석은 하천 식생의 생태서비스와 홍수방어의 하천 치수효과의 최적 솔루션을 제시하기 위한 하도관리의 다양한 방안을 제시하는데 필수적인 정보로 활용될 수 있다.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.99-110
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• 2023

Non-point source (NP) pollutants in an agricultural landuse are discharged from a large area compared to those in other land uses, and thus effective source control measures are needed. To develop appropriate control measures, it is necessary to quantify discharge load of each source and evaluate the degree of water quality improvement by implementing different options of the control measures. This study used Hydrological Simulation Program-FORTRAN (HSPF) to quantify pollutant discharge loads from different sources and effects of different control measures on water quality improvements, thereby supporting decision making in developing appropirate pollutant control strategies. The study area is the Gyeseong river watershed in Changnyeong county, Gyeongsangnam-do, with agricultural areas occupying the largest proportion (26.13%) of the total area except for the forest area. The main pollutant sources include chemical and liquid fertilizers for agricultural activities, and manure produced from small scale livestock facilities and applied to agriculture lands or stacked near the facilities. Source loads of chemical fertilizers, liquid fertilizers and livestock manure of small scale livestock facilities, and point sources such as municipal wastewater treatment plants (WWTPs), community WWTPs, private sewage treament plants were considered in the HSPF model setup. Especially, NITR and PHOS modules were used to simulate detailed fate and transport processes including vegitation uptake, nutrient deposition, adsorption/desorption, and loss by deep percolation. The HSPF model was calibrated and validated based on the observed data from 2015 to 2020 at the outlet of the watershed. The calibrated model showed reasonably good performance in simulating the flow and water quality. Five Pollutants control scenarios were established from three sectors: agriculture pollution management (drainge outlet control, and replacement of controlled release fertilizers), livestock pollution management (liquid fertilizer reduction, and 'manure management of small scale livestock facilities) and private STP management. Each pollutant control measure was further divided into short-term, mid-term, and long-term scenarios based on the potential achievement period. The simulation results showed that the most effective control measure is the replacement of controlled release fertilizers followed by the drainge outlet control and the manure management of small scale livestock facilities. Furthermore, the simulation showed that application of all the control measures in the entire watershed can decrease the annual TN and TP loads at the outlet by 40.6% and 41.1%, respectively, and the annual average concentrations of TN and TP at the outlet by 35.1% and 29.2%, respectively. This study supports decision makers in priotizing different pollutant control measures based on their predicted performance on the water quality improvements in an agriculturally dominated watershed.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.207-215
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• 2002

Changes in salinity, hydraulic conductivity and penetration resistance in a reclaimed tidal land reclaimed in 1986 were studied. The salinity monitoring based on electrical conductivity of saturated extract, ECe, was conducted from 1994, when the land use for experimental crop production started after tile drainage. The site was abandoned since 1999. The hydraulic conductivity was measured by a sand fill auger hole method, and the resistance was measured with a dynamic penetrometer in situ. The averaged ECe in 1994 was $33.7dS\;m^{-1}$ ranging from 25.5 to $44.8dS\;m^{-1}$, and was decreased to $25.7dS\;m^{-1}$ with large range from 0.8 to $70.3dS\;m^{-1}$ before experiment was $1.89{\times}10^{-7}m\;s^{-1}$. It increased to $1.32{\times}10^6m\;s^{-1}$ in the top 20-cm soil with large variability, while it showed $3.44{\times}10^7m\;s^{-1}$ beneath the 20-cm soil depth with less variability. The penetration resistance of the soil ranged from 0.05 to 9.99MPa. The vertical distribution of penetration resistance indicated the hardened layer was developed at the depth of 20~40 cm where the hydraulic conductivity was sharply decreased.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.271-277
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• 2011

To improve the quality of water from water supply source and to establish the management plan of dead plants in flood control reservoir around Juam Lake, the effect of water quality by dead plant in column with passing time was investigated. In column test, the amounts of release by Carex dimorpholepis were $7,893-7,917mg\;m^{-2}\;month^{-1}$ COD, $2,711-2,816mg\;m^{-2}\;month^{-1}$ T-N and $342-547mg\;m^{-2}\;month^{-1}$ T-P. The amounts of release by Miscanthus sacchariflorus were $6,487-6,507mg\;m^{-2}$ COD, $1,813-1,868mg\;m^{-2}$ T-N and $226-405mg\;m^{-2}\;month^{-1}$ T-P in column. Therefore, the release of COD, T-N and T-P by Carex dimorpholepis were more than those by Miscanthus sacchariflorus Benth in column.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.324-332
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• 2014

In order to reveal the long-term variations of water quality in Jinhae Bay, water qualities had been monitored at 9 survey stations of Jinhae Bay during 2000~2012. The surface and bottom waters concentrations of chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chlorophyll-a (Chl.-a) were higher at the survey stations of Masan Bay than the stations of other Bays. Especially, station 1 which is located at the inner area of Masan Bay had the highest values in the concentrations of COD, DIN, and Chl.-a because there were terrestrial pollutant sources near the station 1 and sea current had not well circulated in the inner area of Masan Bay. In factor analysis, the station 1 also had the highest factor values related to factors which increase organic matters and nutrients in surface and bottom waters of Masan Bay. However, the stations (st.5, st.6, st.7, st.8, and st.9) of other Bays had lower values of the factors. In time series analysis, the COD concentrations of the bottom waters at 8 stations except for station 1 distinctly decreased. However, the COD concentrations of the surface waters showed no distinct decrease trends at all stations. In the concentrations of nutrients (DIN and DIP) of both surface and bottom waters, there were tremendous decrease trends at all stations. Therefore, these distinct decrease trends of the COD in bottom waters and the nutrients in surface and bottom waters of Jinhae Bay could have been associated with water improvement actions such as TPLMS (total pollution load management system).

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.147-154
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• 1999

This study was carried out to obtain reasonable management method of salt-affected soil for ecological restoration in the reclaimed land. Chemical properties of reclaimed soil was investigated base on reclamation years. Ionic acitivity in soil and satruration extract were analyzed to estimate the effect of salt interception by planting ground treatment. The soil porperties of reclaimed land was saline-sodic soil with $11.3dSm^{-1}$ of electrical conductivity, 34.8% of exchangeable sodium percent in first reclamation year. Electrical conductivity, exchangeable sodium and exchangeable chlorine were remarkedly decreased during six years after reclamation but chemical properties of reclaimed soil was unsuitable status for tree growth. Exchangeable sodium perecnt was higher in the neighborhood parks and street tree sites than in the buffer green spaces and was higher in subsoil than in topsoil of profile in all sites. Content of soduim, chloride and sulfate in saturation extract were more than other ions. Content of soduim and chloride were higher in the neighborhood parks and street tree sites than in the buffer green spaces and were higher in subsoil than in topsoil. Content of calcium plus magnesium of soil was higher in the buffer green space than in the neighborhood park and street tree but content of calcium and magnesium in saturation extract were higher, as result from exchangeable sodium, in the neighborhood parks and street tree sites than in the buffer green spaces. Concentration of salt in soil showed the difference with mounding height and planting ground treatment. The lowest concentration of salt appeared in buffer green spaces and street tree sites was the highest. Salt interception by mounding height in the same planting ground treatment was more effective 120cm of mounding height than 70cm of mounding height.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.172-180
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• 1993

Chemical properties of the soils were surveyed in the field of vinyl houses concentrated in the area of Bunpyong-dong and Shinchon-dong of Cheongju, Chilgeum-dong of Chungju and Gageum-myeon of Jungweon-gun. Chungcheongbuk-do province. 1. Content of chemical component of the soil in the vinyl house was higher than in open field. In more than half of the vinyl house soils surveyed, electric conductivity was more than 4.0 mmhos/cm and available phosphate was more than 1,000ppm. 2. Contents of availble phosphate and exchangeable potassium were increased with years of cultivation and their content of accumulation in soil were in the order of Bunpyong-dong>Shinchon-dong>Gageum-myeon>Chilgeum-dong. While their mobility was comparatively low. 3. $NO_3$-N content was remarkably higher in vinyl house soil and the older in cultivation made $NO_3$-N content higher same as the case of available phosphate content. However easy leaching of $NO_3$-N through soil profile is expected due to the fact that $NO_3$-N content was rapidly decreased by removal of polyethylene film cover from the frame of house after harvest of crops. 4. It is a tendency that various chemical contents of vinyl house soils wer higher in 1992 than in 1988~1990, especially much higher from the area of Bunpyong-dong and Shinchon-dong of Cheongju. 5. Salt accumulation in vinyl house soil has been increased with continuing cultivation. Therefore amount of fertilizer application should be controlled in order to avoid salt toxicity, quality deterioration for crop and salt contamination of ground water.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.92-94
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• 1998

최근 도시근교 시설재배토양의 염류 과다집적과 연작장해 발생으로 생산성이 저하되고 있다. 그리고 고품질 연중생산이 가능한 양액 재배 면적이 '93년 23ha에서 '97년 414ha로 급속히 증가되고 있는데 이 중 약12%가 담액경이나 박막수경의 순수 수경재배 방식이 차지하고 있다. 순환식 담액수경 상추재배를 기준으로 할 때 농가 300평 재배시 약 100ton의 양액이 소요되며 이 양액은 1회 재배가 끝난 후 상당량이 폐기되고 있고 고형 배지경 양액 재배의 경우에도 대부분 비 순환식 재배로 1회 관수 후 나오는 배액이 그대로 버려지고 이어 토양 및 지하수 등 환경오염, 자원 낭비 등의 여러 가지 문제를 야기시키고 있다. (중략)