• 한국지하수토양환경학회지:지하수토양환경
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• 제24권6호
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• pp.26-32
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• 2019

An analysis of groundwater quality is significant for monitoring and managing water contamination and groundwater system. For the purpose of those, the geochemical characteristics of groundwater were studied over the concern for water quality, water type and origin of nitrate nitrogen. Total colony counts were detected in 11 out of 20 samples, and the average value was 31.73 CFU/ml. Range and average of NO₃-N concentrations were 0.9~24.0 mg/L and 8.3 mg/L. All groundwater types were found to be Ca²⁺-HCO₃^-. The range and average of NO₃-N were 0.2~17.4 mg/L and 8.7 mg/L, and those of δ¹⁵N were 1.7~8.9‰, and 5.0‰. Careful consideration is required for evaluating the origin of nitrogen when NO₃-N concentration is low. In general, noticeable difference between rockbed and alluvial water was not found. The ranges of nitrate origins by chemical fertilizer, livestock manure and domestic sewage, and natural soil were 29.6~76.4%, 14.2~58.9% and 2.6~7.0%, and the average values of those were 57.4%, 37.4%, and 5.3%, respectively. Origin of nitrate was affected by more chemical fertilizer than the other parameters. Rockbed water was more affected by chemical fertilizer than alluvial water.

• 한국물환경학회지
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• 제30권5호
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• pp.517-523
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• 2014

In order to remove both nitrate and sulfate present in the concentrate of RO(reverse osmosis) process, a combined bio-regeneration and ion-exchange(IX) system was studied. For this purpose, both denitrifying bacteria(DNB) and sulfate reducing bacteria(SRB) were simultaneously cultivated in a bio-reactor under anaerobic conditions. When the IX column containing a nitrate-selective A520E resin was fully exhausted by nitrate and sulfate, the IX column was bio-regenerated by pumping the supernatant of the bio-reactor, which contains MLSS concentration of $125{\pm}25mg/L$, at the flowrate of 360 BV/hr. Even though the nitrate-selective A520E resin was used, the breakthrough curves of ionic species showed that sulfate was exhausted earlier than nitrate. The reason for this result is due to the fact that the concentration of sulfate in RO concentrate was 36 to 48 times higher than nitrate. The bio-reactor was successfully operated at a volumetric loading rate of 0.6 g $COD/l{\cdot}d$, nitrate-N loading rate of 0.13 g $NO_3{^-}-N/l{\cdot}d$, and sulfate loading rate of 0.08 g $SO_4{^{2-}}/l{\cdot}d$. The removal rate of SCOD, nitrate-N, sulfate was 90, 100, and 85%, respectively. When the virgin resin was fully exhausted and consecutively bio-regenerated for 2 days, 81% of nitrate and 93% of sulfate were reduced. When the virgin resin was repeatedly used up to 4 cycles of service and bio-regeneration, the ion-exchange capacity of bio-regenerated resin decreased to 95, 91, 88, and 81% of virgin resin.

• 한국결정학회지
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• 제1권1호
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• pp.14-18
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• 1990

Econazole nitrate, 1-{2-[(4-chlorophenyl)methoxy]-2-(2,4-dichlorophenyl) ethy1}-1H-imidazole mono-nitrate, C18 H16 CI13 N3 O4의 단위세포 상수는 a=19.337(4) A, b=15.191(5) A c=7.601(3)A, β=91.72(2)μ V=2000.0A3 Do=1.49g/ml Dm=1.47g/ml, M=4.31cm-1 F(000)=912.0, 2T=298K,공간군은 P2₁/C이고 단사 정계이며 Z=4이다. λ=(Mo-Ka)=0.7107 A을 사용한 1330개의 Intensity data에 대해 최종 R값은 0.06이다. Econazole nitrate의 각 세 ring은 각각 평면이며 B,A,C ring순서로 층계를 이루고 있다. 반면에 Econazole의 A와 C ring은 거의 같은 평면에 누워 있으나 B ring 은 거의 같은 평면이며 B,A,C ring순서로 층계를 이루고 있다.반면에 Econazole의 A와 C ring은 거의 같은 평면에 누워있으나 B ring과는 약 60˚의 평면각을 이루고 있다. Nitrate의 O(*3)와 Imidaze의 N(2) 사이의 수소결합은 Econazole slt의 안정화에 기여한다.

• Ocean Science Journal
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• 제41권3호
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• pp.125-137
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• 2006

Nutrients, chlorophyll-a, particulate organic carbon (POC), and environmental conditions were extensively investigated in the northern East China Sea (ECS) near Cheju Island during three seasonal cruises from 2003 to 2005. In spring and autumn, relatively high concentrations of nitrate ($2.6{\sim}12.4\;{\mu}mol\;kg^{-1}$) and phosphate ($0.17{\sim}0.61\;{\mu}mol\;kg^{-1}$) were observed in the surface waters in the western part of the study area because of the large supply of nutrients from deep waters by vertical mixing. The surface concentrations of nitrate and phosphate in summer were much lower than those in spring and autumn, which is ascribed to a reduced nutrient supply from the deep waters in summer because of surface layer stratification. While previous studies indicate that upwellings of the Kuroshio Current and the Changjiang (Yangtze River) are main sources of nutrients in the ECS, these two inputs seem not to have contributed significantly to the build-up of nutrients in the northern ECS during the time of this study. The lower nitrate:phosphate (N:P) ratio in the surface waters and the positive correlation between the surface N:P ratio and nitrate concentration indicate that nitrate acts as a main nutrient limiting phytoplankton growth in the northern ECS, contrary to previous reports of phosphate-limited phytoplankton growth in the ECS. This difference arises because most surface water nutrients are supplied by vertical mixing from deep waters with low N:P ratios and are not directly influenced by the Changjiang, which has a high N:P ratio. Surface chlorophyll-a levels showed large seasonal variation, with high concentrations ($0.38{\sim}4.14\;mg\;m^{-3}$) in spring and autumn and low concentrations ($0.22{\sim}1.05\;mg\;m^{-3}$) in summer. The surface distribution of chlorophyll-a coincided fairly well with that of nitrate in the northern ECS, implying that nitrate is an important nutrient controlling phytoplankton biomass. The POC:chlorophyll-a ratio was $4{\sim}6$ times higher in summer than in spring and autumn, presumably because of the high summer phytoplankton death rate caused by nutrient depletion in the surface waters.

• 한국세라믹학회지
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• 제46권6호
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• pp.592-595
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• 2009

Nanosize NiO powder was prepared by mixing acidic nickel nitrate with basic nickel carbonate. The particle size and morphology of NiO were mainly governed by the mole ratio of the nitrate to the carbonate. The effects were studied by DSC, XRD, FTIR, and SEM. Heat treatment conditions influence the particle size distribution of produced NiO powder extensively for the case of 3N7C (3 moles of the nitrate and 7 moles of the carbonate) and 4N6C, but only slightly for 1N9C and 2N8C. Uniform pseudospherical NiO particles were obtained in $50{\sim}70$ nm for 1N9C and $30{\sim}60$ nm for 2N8C by calcination at $750{^{\circ}C}$ for 2 h.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.471-478
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• 2011

The objectives were to compare the ability of various rumen microbial fractions to reduce nitrate and to assess the effect of nitrate on in vitro fermentation characteristics. Physical and chemical methods were used to differentiate the rumen microbial population into the following fractions: whole rumen fluid (WRF), protozoa (Pr), bacteria (Ba), and fungi (Fu). The three nitrogen substrate treatments were as follows: no supplemental nitrogen source, nitrate or urea, with the latter two being isonitrogenous additions. The results showed that during 24 h incubation, WRF, Pr and Ba fractions had an ability to reduce nitrate, and the rate of nitrate disappearance for the Pr fraction was similar to the WRF fraction, while the Ba fraction needed an adaptation period of 12 h before rapid nitrate disappearance. The WRF fraction had the greatest methane ($CH_4$) production and the Pr fraction had the greatest prevailing $H_2$ concentration (p<0.05). Compared to the urea treatment, nitrate diminished net gas and $CH_4$ production during incubation (p<0.05), and ammonia-N ($NH_3$-N) concentration (p<0.01). Nitrate also increased acetate, decreased propionate and decreased butyrate molar proportions (p<0.05). The Pr fraction had the highest acetate to propionate ratio (p<0.05). The Pr fraction as well as the Ba fraction appears to have an important role in nitrate reduction. Nitrate did not consistently alter total VFA concentration, but it did shift the VFA profile to higher acetate, lower propionate and lower butyrate molar proportions, consistent with less $CH_4$ production by all microbial fractions.

• 한국토양비료학회지
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• 제42권4호
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• pp.301-306
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• 2009

이 연구의 목적은 건강한 작물과 시들은 식물의 질소대사와 아스코리빈산 함량의 차이를 비교하는것에 있다. 시듬은 인공적으로 유도되었으며, 그방은 질소과다 시비 및 저칼륨 시비에 의한 것으로4개의 처리구를 두었다. 1N-1P-1K (control), 6N-1P-0K (0K), 6N-1P-0.5K (0.5K), and 6N-1P-2K (2K). 시듬 정도는 control, 0%; 2K, 10%; 0.5K, 40%; and 0K, 70%. 식물 생장에는 고질소 저 칼륨 처리구에서는 그리 큰 차이가 없었으며 질산태질소의 함량은 control 구와 비교하여 고 질소 처리구가 높았으며, 아스코리빈 산 함량은 고질소 처리구가 control구에 비하여 낮았음을 확인 할수 있었다.

• 한국토양비료학회지
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• 제30권1호
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• pp.84-88
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• 1997

시설재배조건하에서 토양의 질산태질소함량과 시용질소에 대한 배추의 수량반응 및 시비효율 등을 검토한 결과를 요약하면 다음과 같다. 토양의 $NO_3{^-}-N$함량은 배추의 수량 및 질소흡수량과는 유의한 정상관, 시비효율과는 유의한 부의 상관이 있어서, 시험전 토양의 $NO_3{^-}-N$ 310mg/kg정도 있으면 질소무비재배가 가능하였다. 질소시비량 추정회귀식에서 시험전토양의 질산태질소함량에 따른 배추의 질소시비량 추천식은 y=-1.424x+441.356(x:시험전토양의 $NO_3{^-}-N$, mg/kg, y:질소시비량 kg/ha)이었다.

• 아시안잔디학회지
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• 제1권1호
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• pp.49-55
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• 1987

Zoysia japonica를 부위별로 나누어서 그들간의 amylase와 nitrate reductase의 활성을 조사한 결과는 다음과 같다. 1. Amylase의 활성은 관부에서 8.36~9.46 unit/mg.rotein/hr.로 가장 높았고 이삭에서 2.04 unit/mg.rotein/hr.로 가장 낮았다. 포복경, 뿌리, 잎에서의 amylase의 활성을 각각 5.42~5.82, 3.76, 2.32~3.16 unit/mg.rotein/hr.나타내었다. 2. Nirate reductase의 활성은 빛을 많이 받는 잎에서 0.35~0.66 n mole/mg.rotein/hr.로 가장 높았고 관부에서 0.06~0.10 n mole/mg.rotein/hr.로 가장 낮았다. 이삭과 포복경에서는 각각 0.31,0.27~0.63 n mole/mg.rotein/hr.를 나타내었다. 이러한 결과로부터 저장기관인 관부나 관부 절간에서 높은 amylase의 활성을 이용하여, 양분을 이삭으로 이동시키고 있음을 알 수 있었다. nitrate reductase의 활성은 chloroplast를 갖지 않는 기관보다 광합성기관에서 더 높았다. 잔디밭에서 같이 사는 크로버와 비교해 보면 amylase의 활성이 Zoysia japonica보다 2배가량 더 높았다. 이러한 결과로부터 잔디밭에서 크로버가 더 생장력이 큼을 알 수 있었다.

• 한국물환경학회지
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• 제33권6호
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• pp.661-669
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• 2017

A distributed watershed model CAMEL (Chemicals, Agricultural Management and Erosion Losses) was applied to a small rural watershed where intensive livestock farming sites are located to estimate nitrate leaching rates from soil to groundwater. The model was calibrated against the stream flows, and T-N and $NO_3-N$ concentrations were observed at the watershed outlet for three rainfall events in 2014. The simulation results showed good agreement with the observed stream flows ($R^2=0.67{\sim}0.93$), T-N concentrations ($R^2=0.40{\sim}0.58$) and $NO_3-N$ concentrations ($R^2=0.43{\sim}0.65$). The estimated annual nitrate leaching rate of the watershed was 33.0 kg N/ha/yr. The contributing proportions of individual activities to the total nitrate leaching rate of the watershed were estimated for livestock farming, applications of chemical fertilizer, and manure. The simulation results showed that the highest contributor to the nitrate leaching rate of the watershed was chemical fertilizer applications. The simulation period was for one year only, however, and results may vary depending on different conditions. Gathering input data over a longer period of time and monitoring data for calibration is needed. When this has been accomplished, it is expected that this model can be applied to small rural watersheds for evaluating temporal and spatial variations of nitrogen transformations and transport processes.