• 한국물환경학회지
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• 제28권3호
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• pp.409-417
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• 2012

SWAT model was applied for the Nakdong River Basin to characterize water quality variability and assess the feasibility of using the load duration curve to water quality management. The basin was divided into 67 sub-basins considering various watershed environment, and rainfall runoff and pollutant loading were simulated based on 6 year measurements of meteo-hydrological data, discharge data of treatment plants, and water quality data (SS, T-N and T-P). The results demonstrate that non-point source loads during wet season increase by 80 ~ 95% of total loads. Although the rate of water flow governs the amount of SS that is transported to the main streams, nutrient concentrations are highly elevated during dry season by being concentrated. This phenomenon is more pronounced in the lower basin, receiving large amounts of urban point source discharges such as treated sewages. Also, the load duration curves (LDC) demonstrate dominant source problems based on the load exceedances, showing that SS concentrations are associated with the rainy season and nutrients, such as T-P, may be more concentrated at low flow and more diluted at higher flow. Overall, the LDC method could be used conveniently to assess watershed characteristics and pollutant loads in watershed scale.

• 한국환경과학회지
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• 제16권3호
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• pp.369-376
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• 2007

This study was conducted to evaluate water quality in coastal sea of Kunsan using multivariate analysis. The analysis data in Coastal Sea of Kunsan use of surveyed data by the NFRDI from April 2000 to November 2002. Twelve water Quality parameter were determined on each sample. The results was summarized as follow ; Water quality in coastal sea of Kunsan could be explained up to 62.782% by four factors which were included in loading of nitrogen-nutrients by Keum river(24.688%), suspended solids variation (12.180%), seasonal climate variation (18.367%) and variation of DIP (10.546%). To analyze spatially and monthly variation by factor score, it was divided by inner area and outer area spatially, and spring and summer monthly. The result of time series analysis by factor score, inner area of Kunsan coastal sea(St.1 and St. 2) was the most affected by nitrogen-nutrient and suspended solids due to runoff by Keum river. It could be suggested from these results that it is important to reduce tile pollution loads from Kuem river for the control of the water quality in coastal sea of Kunsan.

• 한국식품저장유통학회지
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• 제30권4호
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• pp.589-601
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• 2023

Malaysian honey is rich in nutrients and bioactive compounds, which can be a healthy alternative to refined sugar in food production. However, liquid honey's viscous and sticky nature makes it unpreferable in industrial handling. This study, an atomization system coupled with vacuum drying to produce honey powders to overcome the problem. Three types of Malaysian honey, namely Acacia, Gelam, and Tualang, were encapsulated in Ca-alginate gel beads using the atomization system. The density viscosity, and surface tension of the honey-alginate solutions were measured, and the concentration of honey and alginate influenced the physical properties of the solutions. Honey-encapsulated gel beads in the size range of 2.16-2.92 mm were produced using the atomization system with the air-liquid mass flow rate ratios of 0.22-0.31, Weber number (We) of 112-545, and Ohnersorges number (Oh) of 0.35-10.46. Gel bead diameter can be predicted using a simple mathematical model. After vacuum drying, the honey gel powder produced was in the size range of 1.50-1.79 mm. Results showed that honey gel powders with good encapsulation efficiency and high honey loading could be produced using the atomization system and vacuum drying.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.629-632
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• 1999

Constructed wetlands are being used for the removal of nutrients from livestock wastewater. However, natural vegetation typically used in constructed wetlands does not have marketable value. As an alternative, agronomic plants grown under flooded or saturated soil conditions that promote denitrification can be used. Studies on constructed wetlands for swine wastewater were conducted in wetland cells that contained either natural wetland plants or a combination of soybeans and rice for two years with the objective of maximum nitrogen reduction to minimize the amount of land required for terminal treatment. Three systems, of two 3.6 by 33.5 m wetland cells connected in series were used; two systems each contained a different combination of emergent wetland vegetation: rush/bulrush (system 1) and bur-reed/cattail (system 2). The third system contained soybean (Glycine max) in saturated-soil-culture (SSC) in the first cell, and flooded rice (Oryza sativa) in the second cell. Nitrogen (N) loading rates of 3 and $10kg\;ha^{-1}\;day^{-1}$ were used in the first and second years, respectively. These loading rates were obtained by mixing swine lagoon liquid with fresh water before it was applied to the wetland. The nutrient removal efficiency was similar in the rush/bulrush, bur-reed/cattails and agronomic plant systems. Mean mass removal of N was 94 % at the loading rate of $3kg\;N\;ha^{-1}\;day^{-1}$ and decreased to 71% at the higher rate of $10kg\;N\;ha^{-1}\;day^{-1}$. The two years means for above-ground dry matter production for rush/bulrushes and bur-reed/cattails was l2 and $33Mg\;ha^{-1}$, respectively. Flooded rice yield was $4.5Mg\;ha^{-1}$ and soybean grown in saturation culture yielded $2.8Mg\;ha^{-1}$. Additionally, the performance of seven soybean cultivars using SSC in constructed wetlands with swine wastewater as the water source was evaluated for two years, The cultivar Young had the highest yield with 4.0 and $2.8Mg\;ha^{-1}$ in each year, This indicated that production of acceptable soybean yields in constructed wetlands seems feasible with SSC using swine lagoon liquid. Two microcosms studies were established to further investigate the management of constructed wetlands. In the first microcosm experiment, the effects of swine lagoon liquid on the growth of wetland plants at half (about 175 mg/l ammonia) and full strength (about 350 mg/l ammonia) was investigated. It was concluded that wetland plants can grow well in at least half strength lagoon liquid. In the second microcosm experiment, sequencing nitrification-wetland treatments was studied. When nitrified lagoon liquid was added in batch applications ($48kg\;N\;ha^{-1}\;day^{-1}$) to wetland microcosms the nitrogen removal rate was four to five times higher than when non-nitrified lagoon liquid was added. Wetland microcosms with plants were more effective than those with bare soil. These results suggest that vegetated wetlands with nitrification pretreatment are viable treatment systems for removal of large quantities of nitrogen from swine lagoon liquid.

• 환경생물
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• 제39권2호
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• pp.184-194
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• 2021

부남호는 하굿둑 건설 이후 수질이 급격히 악화되어 농업용수로 사용이 불가할 만큼 본래의 기능을 상실하였다. 따라서 해수 교환이나 유통의 필요성이 있으나, 극히 오염된 부남호의 물을 대량 방류할 시 문제가 야기될 수 있기 때문에 시기에 따른 환경 조사가 중요하다. 따라서 본 연구에서는 갈수기(4월)와 강우기(7월)에 천수만과 부남호의 수질 및 식물플랑크톤 분포 특성을 조사하였다. 갈수기에는 부유 생물이 정체되어 부남호 내에서 남조류 Oscillatoria spp. 세포수가 8.92×10⁷ cells L^-1로 대증식하였고, Nitrate+Nitrite을 제외한 영양염 대부분이 소비되었다. 강우기에는 담수 유입의 영향으로 부남호에서 용존 영양염이 크게 증가하였고 부남호에서 식물플랑크톤이 대증식하였다. 강우기 방류의 영향으로 천수만 내측 역시 높은 농도의 생물량을 보였다. 강우기 부남호에서 우점했던 남조류 Oscillatoria spp.와 Microcystis spp.가 천수만 내측에서도 다수 출현하였으며, 해수에서는 Cheatoceros spp., Eucampia zodiacus와 같은 규조류가 빠르게 증식하였다. 부영양화 지수는 부남호 내측에서 1을 초과하여 부영양 해역으로 평가되었다. 천수만은 강우기에 담수 방류의 영향을 받을 경우 부영양화 해역으로 평가되었다. 특히 부남호 내 방조제에 인접한 B3 정점의 8 m 이상 수심에서 정체된 해수 기원의 강한 빈산소 수괴가 관찰되었고, Nitrate+Nitrite를 제외한 영양염 농도가 극단적으로 높았다. 특히 COD 농도가 206 mg L^-1로 심하게 오염된 상태임을 확인하였다. 따라서 부남호는 지속적으로 육상기원의 영양염이 누적되며, 식물플랑크톤의 대발생과 침강으로 수질이 더욱 악화될 가능성이 높은 수역으로 판단되었고, 이를 근본적으로 해결하기 위해서는 해수유통을 통한 생태계 복원이 필수적이다.

• 한국환경과학회지
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• 제23권3호
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• pp.433-445
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• 2014

The objective of study was to analyze seasonal and inter-annual patterns of water chemistry of Miho Stream watershed during 2004 - 2007 along with some influences of tributaries and summer monsoon on the stream water quality. For the study, eight physico-chemical parameters such as nitrogen, phosphorus, BOD, COD and chlorophyll-a (CHL) etc. were analyzed in relation to spatial and temporal variability of seven sampling sites of the mainstream and some tributaries in the watershed. In the upstream reach, Mean of BOD, COD and TP averaged 3.2 mg/L, 6.5 mg/L and $186{\mu}g/L$, respectively, indicating an eutrophic conditions as a III-rank in the stream water quality criteria from the Ministry of Environment, Korea(MEK). The eutrophic water was due to a combined effect of Chiljang tributary with high nutrients ($TP=844{\mu}g/L$, TN=8.087 mg/L) and the point sources from some wastewater treatment plants. In the meantime, BOD, TN, and TP in the downstream reach were about > 1.2-1.5 folds than the values of the midstream reaches. This was mainly attributed to effluents of nutrient rich-water (mean TN: 11.980 mg/L) from two tributaries of Musim Stream and Suknam Stream, which is directly influenced by nearby wastewater disposal plants. Seasonal analysis of water chemistry showed that summer monsoon rainfall was one of the important factors influencing the water quality, and water quality had a large spatial heterogeneity during the rainfall period. In the premonsoon, BOD in the downstream averaged $6.0{\pm}2.47mg/L$, which was 1.4-fold greater than the mean of upstream reach. Mean of CHL-a as an indicator of primary productivity in the water body, was > 2.2 - 2.9 fold in the downstream than in the upstream, and this was a result of the high phosphorus loading from the watershed. Overall, our data suggest that some nutrient controls in point-source tributary streams are required for efficient water quality management of Miho Stream.

• 한국토양비료학회지
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• 제43권2호
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• pp.132-139
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• 2010

To manage the effluent nutrients amounts from rice paddy fields using free range ducks or rice bran, we evaluated the effects of a purifying paddy field which is no fertilizer, no pesticides, and dense rice seedling having a concept of constructed wetland. The experimental paddy field was located at downstream in the watershed of ducks using rice culture area in Milyang. The purifying paddy of land design were treated with seeding method, and vegetation type. As land design, direct seeding on plane, and direct seeding on high-ridge field in 2007. Planting rice only, and planting rice with water hyacinth were treated as vegetation type in purifying paddy in 2008. The purifying paddy fields were effective to reduce amount of T-N and T-P contents in effluent to 33.2~45.3%, and 53.1~55.4%, respectively. The direct seeding on high-ridge treatment, having long residence time of effluent water was more effective than plane plot as T-N 0.29 $g^{-1}m^{-2}d^{-1}$, and T-P 0.031 $g^{-1}m^{-2}d^{-1}$. The planting rice with water hyacinth treatment was effective than planting rice only as T-N 0.23 $g^{-1}m^{-2}d^{-1}$, and T-P 0.049 $g^{-1}m^{-2}d^{-1}$. The optimum area of purifying paddy field to treats all effluent were found out 3.2~4.7% of rice culture area using free range ducks, and rice bran at upper stream.

• 환경생물
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• 제20권1호
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• pp.91-99
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• 2002

오염부하량이 높은 경안천과 오염부하량이 낮은 철원북방 비무장지대내 토교저수지에서 식물플랑크톤의 크기별 현존량과 chlorophyll a농도에 대한 계절적 변화 및 환경요인과의 상호관계를 조사하였다. 또한 식물 플랑크톤의 크기를 고려하여 > $8\mu{m},\;3-8\mu{m},\;<3\mu{m}$ 세포 크기별로 분획하여 현존량과 chl. a 농도를 관찰하였다. 물리.화학적 환경요인은 경안천이 토교저수지보다 높게 나타났다. 식물플랑크톤 현존량은 경안천에서 10배 정도 높았으나 크기별 chl. a의 농도는 두 지점 모두 소형 플랑크톤에서 높은 농도를 보였다. 경안천 식물플랑크톤의 현존량은 대부분 미세형이었지만 chl. a는 부분적으로 극소형 이 우위를 차지하였다. 반면, 토교저수지에서는 현존량은 소형과 미세형이, chl. a는 소형에서 높이 분포하였다. 따라서 영양염 및 물리적 조건이 서로 상이한 수계에서의 식물플랑크톤의 분포는 출현종의 크기를 결정하기도하고 출현종의 특성에 따라 현존량과 chl. a의 불균형적 특성을 유도한다.

• 한국습지학회지
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• 제15권3호
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• pp.329-337
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• 2013

2008년 10월부터 2009년 9월까지 유입수계 하천의 수질특성을 파악하고 통계적 처리를 통하여 수질자료를 해석하였다. 순천만 유입수계 중에서 순천서천, 순천동천, 옥천은 환경부고시 하천수질 평가항목 모두에서 I등급으로 비교적 양호한 수질상태를 보였으나, 하천에서 유기물 오염의 지표인 BOD 항목에 대해서 해룡천과 순천만 유입지점에서는 각각 "약간 나쁨"과 "보통"의 결과를 나타내었다. 한편 총질소과 총인의 경우는 하수종말처리장 방류지점과 해룡천에서 다른 하천에 비해서 상대적으로 높은 결과를 나타내었다. 요인분석 결과 수질특성을 설명하는 1요인으로는 인간기원의 오염물질로서 기여율은 53.7%, 2요인으로는 지형적인 인자로서 기여율은 25.0%로 나타났다. 그리고 3요인은 자연환경의해서 기인된 요인들로서 기여율은 14.2%이며, 누적기여율은 92.8%로 평가되었다. 요인분석 결과 해룡천과 하수종말처리장 방류수로부터 상대적으로 많은 오염물질이 배출되어 순천만으로 유입되고 있어, 순천만의 수질 보존을 위해서는 순천하수종말처리장과 해룡천의 수질오염물질 배출의 보다 철저한 관리와 정화노력이 필요하다고 판단된다.

• 환경영향평가
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• 제26권1호
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• pp.68-77
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• 2017

낙동강 전 권역을 209개 유역으로 나누고 각 유역에서 배출되는 비점오염부하 기여율을 산정하기 위해 HSPF모델을 2012년 2013년을 기준으로 보정 및 검증을 실시하였다. 유량의 경우 보정한 결과 R2가 0.71~0.93, 검증은 0.71~0.79로 비교적 양호한 값으로 산정되었다. 수질의 경우는 % difference로 검 보정을 실시하였는데 보정의 경우 DO는 0.4~9.7 %, BOD는 0.5~30.2 % difference, TN은 낙본 C 및 황강 B를 제외 하고는 1.9~28.6 % difference로 나타났고 검증은 DO 0.2~13.7%, BOD는 1.3~23%, TN은 황강 B를 제외한 0.5~24.3%로 비교적 잘 모의 되었다. 그러나 TP는 농도가 다른 항목에 비해 미량이기 때문에 차이의 범위가 크게 나타났는데 보정의 경우 0.8~55.3 % difference이고 검증에서도 같은 결과를 얻었다. 209개 유역별 BOD 연간 누적부하량을 산정한 결과 RCH 123(경상남도 의령군), RCH 121(경상남도 진주시), RCH 92(대구광역시 달성군) 가 높은 것으로 나타났다. 그러나 영양염류에 대한 유역별 연간 누적부하량의 결과들은 BOD 연간 누적부하량 순위와 일치하지 않는 것으로 나타났다. 본류에 위치한 산림, 습지, 농지 등이 많은 유역들이 상대적으로 산림지역이나 습지가 많은 댐 상류지역의 유역들 보다 BOD 비점오염 부하량이 높은 것으로 나타났다. 토지형질을 비롯한 유역 특성들을 나타나는 다른 인자들이 비점오염 부하량과 밀접한 관계가 있는 것으로 나타났다.