• 한국농공학회논문집
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• 제52권5호
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• pp.27-35
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• 2010

The characteristics of delivered nutrient loads were analyzed and the regression equations to estimate delivery ratios of nutrients (TN and TP) were developed using HSPF simulation results at six subwatersheds within the Bochung A unit watershed during 1998-2007. TN delivery ratio was higher than TP delivery ratio because significant amounts of TP was considered to be attached at soil as ${PO_4}^-$ during delivery process from discharged point of nutrient source to main stream. As a results of correlation analysis, factors related to geomorphic characteristics had not statistical correlation with TN and TP delivery ratios. TN loading rate from living and specific stream flow had statistical negative and positive correlation, respectively, with TN delivery ratio. TP loading rates from all sources and from land cover and specific stream flow had statistical negative, negative and positive correlation, respectively. The specific stream flow represents the most strong correlation with nutrient delivery ratios. The regression equations to estimate delivery ratios for TN and TP were developed by including statistical correlated factors and showed high efficiency of 0.98 and 0.95 of coefficient of determination for TN and TP, respectively.

• 대한환경공학회지
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• 제36권9호
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• pp.609-613
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• 2014

본 연구는 미세조류 생장에 중요한 영향인자인 N/P ratio가 미세조류의 생장과 하수의 영양염류 제거에 미치는 영향을 알아보고자 하였다. 실험을 위하여 1-70까지의 다양한 N/P ratio를 준비하였으며, 미세조류는 Botryococcus braunii를 사용하였다. 실험결과 바이오매스 생산을 위하여 필요한 N/P ratio는 5-30이었다. TN의 제거율은 N/P ratio 1-30까지는 82%, 31-70까지는 73-78%의 제거율을 나타내어 TN 제거를 위한 N/P ratio는 1-30까지가 가장 좋았다. TP의 제거율 N/P ratio 1-20까지는 80% 이상의 높은 제거율을 나타내었지만, 20 이상부터는 급격하게 하락하여 50 이상에서는 22% 정도의 제거율로 변화가 없이 일정하였다. 따라서 바이오매스 생산량과 하수에서의 TN, TP의 제거를 위한 N/P ratio는 1-30이 가장 좋은 비율로 나타났다. TN, TP 제거율과 바이오매스의 생산량 상관관계는 TP 제거율과 바이오매스 생산량의 상관계수가($R^2$) 0.9126으로 상관관계가 매우 높았으나, TN 제거율과 바이오매스 생산량과의 상관관계는 찾을 수가 없었다. 이는 하수에서 TP의 함량이 TN의 함량보다 바이오매스 생산량에 밀접한 관계가 있음을 알 수 있다.

• Environmental Engineering Research
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• 제19권3호
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• pp.223-228
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• 2014

We investigated seasonal algae variability and its influence on water quality in an agricultural reservoir. We observed that maximal total phosphorus (TP) loads were 1,715 kg from farmland in September, which changed the ecosystem in the reservoir. At this time, Dictyosphaerium pulchellum as green algae dominated. Aulacoseira ambigua as diatom became the most dominant from November 2010 to May 2011. The diatom was sensitive to water temperature. Microcystis spp. and Oscillatoria spp. as cyanobacteria were dominant during summer and fall, and sank down to the sediment during winter and spring. Increasing water temperature during summer causes anaerobic conditions in the sediment, leading to regrowth of cyanobacteria. With regard to the ratio of total nitrogen (TN) to TP, green algae and cyanobacteria were dominant at TN:TP ratios less than 20-30. Diatoms were dominant at TN:TP ratios greater than 30-40. Statistical analysis indicated that diatom growth was dependent on water temperature and TN concentration. TP concentration and water temperature were the key factors for the growth of cyanobacteria and green algae. From these results of this study, the management of land-use was an important parameter for improving water quality in the agricultural reservoir.

• 한국농공학회논문집
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• 제52권3호
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• pp.65-71
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• 2010

This study was conducted to investigate the dynamics of nutrients such as total nitrogen (TN), nitrate nitrogen ($NO_3$-N) total phosphorous (TP), and phosphate phosphorous ($PO_4$-P) in outflow from a cabbage farmland in a mixed land-use watershed. The TN concentrations in groundwater showed twice peaks in late July 2006 and late March 2007 (3.8, 4.7 mg/L, respectively), when it rained shortly after fertilizer application, indicating that nitrogen leaching is greatly influenced by fertilization and rainfall. The mean concentrations of TN and $NO_3$-N in surface water were not significantly higher than those in groundwater, while the mean concentrations of TP and $PO_4$-P in surface water were significantly (p < 0.05) were higher than those in groundwater. The TN concentrations in groundwater were generally higher than those in surface water during fertilization and early growing season due to the effect of fertilization, but vice versa in the other periods. In contrast, the TP concentrations in groundwater were always lower than those in surface water due to the sorption of particulate phosphorous by soil. The ratio of TN load in baseflow to that in total TN load (39 %) was much greater than the TP ratio (7 %), suggesting that baseflow contribute to nitrogen export. Therefore, proper fertilization management should be taken to reduce nitrogen load through baseflow.

• 분석과학
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• 제12권4호
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• pp.312-317
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• 1999

저농도, 고농도의 BOD, COD, TN, TP 항목에 대해 13개 기관을 대상으로 정도관리를 실시하였다. 정도관리 평가값은 6회에 걸쳐 주기적으로 반복측정한 평균치로 정하였으며, 이 값은 실제 조제한 값으로부터 오차율이 5%이내였으며, 표준편차도 0.44 (BOD, 저농도), 2.15 (BOD, 고농도), 0.12 (COD 저농도), 1.63 (COD 고농도), 0.35 (TN 저농도), 1.99 (TN 고농도), 0.05 (TP, 저농도), 0.14 (TP, 고농도)으로 정밀도가 아주 우수한 것으로 나타났다. 6회에 걸쳐 주기적으로 반복측정하여 허용상하한값과 경고상하한값을 구하여 정도관리차트를 얻었으며, 이 차트에 따라 평가한 결과 BOD 저농도의 경우 3개 기관이 5.30, 9.70, 5.30 mg/L로 허용상하한값을 벗어났으며, 고농도는 5개 기관이 허용상하한값을 벗어나 BOD 측정분석의 신뢰도가 다소 좋지 않은 것으로 나타났다. COD 저농도의 경우 4개 실험실, 고농도는 2개 기관이 41.00, 30.60 mg/L로 허용상하한값을 벗어났으며, 그외의 11개 기관은 신뢰할 수 있는 측정분석 결과를 산출하였다. TN 저농도의 경우 1개 기관만이 0.70 mg/L로 허용 하한값을 벗어났지 그외의 11개 기관은 거의 평가값에 가까운 우수한 측정분석 결과를 산출하였으며, 고농도는 거의 대부분인 11개 기관이 허용상하한값의 범위를 벗어나 측정분석 결과에 대한 신뢰도 향상에 보다 더 중점을 두어야 할 것으로 나타났다. TP 저농도의 경우 4개 기관이 1.14, 0.45, 0.64, 1.49 mg/L로 허용 상하한값을 벗어났으며, 고농도는 7개 기관이 허용 상하한값을 벗어나 TP 측정 분석의 신뢰도가 다소 좋지 않은 것으로 나타났다.

• ALGAE
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• 제32권4호
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• pp.275-284
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• 2017

Microcystis aeruginosa causes harmful algal blooms in the Nakdong River of Korea. We studied the effect of different concentrations and ratios of ammonium ($NH_4{^+}$), nitrate ($NO_3{^-}$), and phosphate ($PO{_4}^{3-}$) on growth of this species in BG-11 medium: each nutrient alone, $NO_3{^-}:NH_4{^+}$ ratio, the N : P ratio with fixed total N (TN), and the N : P ratio with fixed total P (TP). The single nutrient experiments indicated that M. aeruginosa had the highest growth rate at $NH_4{^+}$ and $NO_3{^-}$ concentrations of $500{\mu}M$, and at a $PO{_4}^{3-}$ concentration of $5{\mu}M$. The $NO_3{^-}:NH_4{^+}$ ratio experiments showed that M. aeruginosa had the highest growth rate at a ratio of 1 : 1 when TN was $100{\mu}M$ and $250{\mu}M$, and the lowest growth rate at a ratio of 1 : 1 when the TN was $500{\mu}M$. The N : P ratio with fixed TN experiments indicated that M. aeruginosa had the highest growth rates at 50 : 1, 20 : 1, and 100 : 1 ratios when the TN was 100, 250, and $500{\mu}M$, respectively. In contrast, the N : P ratio with fixed TP experiments showed that M. aeruginosa had the highest growth rates at 200 : 1 ratio at all tested TP concentrations. In conclusion, our results imply that the $NO_3{^-}:NH_4{^+}$ ratio and the $PO{_4}^{3-}$ concentration affect the early stage of growth of M. aeruginosa. In particular, our results suggest that the maximum growth of M. aeruginosa is not simply affected by the $NO_3{^-}:NH_4{^+}$ ratio and the N : P ratio, but is determined by the TN concentration if a certain minimum $PO{_4}^{3-}$ concentration is present.

• 생태와환경
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• 제41권4호
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• pp.512-518
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• 2008

This study were to evaluate trophic conditions, N : P ratios, and empirical relations of chlorophyll (CHL) systematically using TN, TP, and CHL values in agricultural reservoirs and drinking water supplying dams. During the study, nutrients and CHL varied depending on seasonal conditions and types of the reservoirs, but most reservoirs were diagnozed as eutrophic to hypertrophic. Mass ratios of TN : TP averaged 93.1 (range: $0.68{\sim}1342$) and about 96.6 % of the total observations (n=516) was > 17 in the N : P ratios. This result suggests that P was a potential factor limiting algal growth in the entire reservoir. Thus, TN : TP ratios were a function of phosphorus rather than nitrogen. Regression analysis of log-transformed N : P ratios against TP in DWDRs and ARs showed that ratios were linearly declined with an increase of TP ($R^2$>0.66; p<0.001). Seasonal mean CHL was minimum ($4.3{\mu}g\;L^{-1}$, range: $0.1{\sim}39.7{\mu}g\;L^{-1}$) in premonsoon, and was similar between the monsoon and postmonsoon. In contrast, one of the tremendous features was that values of CHL was greater in the ARs than DWDRs. Thus, the spatial and temporal patterns in CHL were similar to those of TP but not TN. Empirical models of CHL-TP showed that CHL variation could explain average 15.3% and 11.3% in DWDRs and ARs, respectively. Seasonal analysis of empirical models showed that CHL-TP relations were stronger in postmonsoon than those of premonsoon and monsoon.

• 한국농공학회지
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• 제44권3호
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• pp.136-145
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• 2002

Monitoring data from agricultural reservoirs throughout the country were analyzed to evaluate the limiting factor fur algal growth and relationships between Chl-a, total phosphorus (TP), and total nitrogen (TN). Total 394 reservoirs ranging from below 500 ㎥ to over 50 million ㎥ in storage volume were monitored from 1990 to 2000 with respect to TP, W, Chl-a, and their annual mean values were used fur the analysis. Based on N/P ratio, the dominant limiting factor for algal growth was turned out to be phosphorus in agricultural reservoirs (about 83%). Therefore, the proper managements of phosphorus in the agricultural watershed appear to be crucial to prevent excessive on algal growth. The effects of phosphorus and nitrogen ware most eminent during the summer period. And the effect of nutrients on the algal biomass (Chl-a) development appeared to be greater in smaller the reservoirs than in larger ones. Generally, Chl-a and TP demonstrated a close relationship while that of Chl-a and TN showed less correlationship. Chl-a and chemical oxygen demand (COD) also showed a good relationship. Beth ratios of Chl-a / TP and Chl-a / COD relationships were within the range of literature values. Quantitative analysis of TP and COD is relatively convenient compared to that of Chl-a, and the relationship between TP and COD and Chl-a from this study could be used beneficially for water quality management of agricultural reservoirs and related water quality modeling.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.567-570
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• 2003

Nutrients behavior were investigated at a paddy fields area(Soro-ri) with large-scaled plots on loam soil during irrigation seasons of $2001{\sim}2002$. The average concentration of TN, TDN and TDP in drainage water was higher than that in irrigation water. On the other hand, TP in irrigation water was higher than that in drainage water. The ratio of a TDN to TN accounts for over 90% and the ratio of TDP to TP accounts for $50{\sim}70%$. Especially, the ratio of TDP to TP in drainage water was bigger than that in irrigation water, suggesting that much of particulate component was reduced due to sedimentation and adsorption in paddy fields plots.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.543-546
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• 2004

Nutrients behavior were investigated at a paddy fields area(Soro-ri) with large-scaled plots on loam soil during irrigation seasons of $2001\~2003$. The average concentration of TN, TDN and TDP in drainage water was higher than that in irrigation water. On the other hand, the average concentration TP in irrigation water was higher than in drainage water. The ratio of TDN to TN accounted (or over $90\%$ and the ratio of TDP to TP accounted for $50\~70\%$. Especially the ratio of TDP to TP in drainage water was higher than that in irrigation water, suggesting that much of particulate component was reduced due to sedimentation and adsorption in paddy fields plots. Overall, particulate phosphorus usually account for 44 to $77\%$ of tile total phosphorus during storm events.