• Korean Journal of Soil Science and Fertilizer
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• v.42 no.1
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• pp.14-20
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• 2009

Classification of land uses and analysis of nitrogen isotope fractionation in groundwater nitrate were carried out to examine its contamination sources in Jeju province. ${\delta}^{15}N$ values of urea (hydrolyzed with urease), ammonium sulfate, compost, water from septic tank were -1.7, -5.8, +14.1, and +24.0‰, respectively. Urea, when it was directly distillated, showed -16.5‰. Based on these ${\delta}^{15}N$ values, sources of nitrate could be classified as originated from chemical fertilizers with ${\delta}^{15}N$ values below +5‰ and as from animal manure or municipal waste with ${\delta}^{15}N$ values over +10‰. Results of ${\delta}^{15}N$ analysis of 33 wells showed that most wells had the chemical fertilizers as their dominant contamination source. However, some wells were contaminated by other sources: animal wastes or municipal wastes. Some wells were also contaminated by the combined sources of nitrate. It was also demonstrated that ${\delta}^{15}N$ analysis could be a useful tool even in the case where no apparent contamination source is found.

• Journal of the Korean earth science society
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• v.33 no.6
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• pp.481-496
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• 2012

REE, major and trace elements, and Sr-Nd isotopic ratios of surface sediments around Jeju Island were analyzed for identifying the origin of the sediments. The Chemical Index of Alteration (CIA) between 44.2 to 68.9 (av. 59.4) shows a similarity with the Huanghe sediment. The most sediments found within the study areas show a very similar chondrite-normalized REE pattern that has enriched LREE ($La_{(N)}/Sm_{(N)}$ >3) and small negative Eu anomaly, typically of average shales. The UCC-nornalized REE patterns of the southwestern offshore sediment samples show a very similar pattem with the Changjiang sediment with enriched in most REE and more convex REE pattern than those of the Huanghe and Keum rivers sediments, which indicates that the Changjiang River's suspended sediments have been transported into the western part of Jeju Island. The $^{87}Sr/^{86}Sr$ isotopic ratios vs ${\varepsilon}_{Nd}(0)$ values were thus used as a tracer to discriminate the provenance of sediments in the study area. Based on the discriminated diagram, it clearly showed that most sediments in the western and northwestern part were closely plotted with sediments of the Huanghe River. However, the sediments in the southwestern part near the Changjianf estuary were closely plotted with submerged delta sediments of the Changjiang River. In contrast, the sediment samples of the northeastern part showed discriminative figures from those of the Chinese rivers. It suggests that sediments around Jeju Island must be originated from diverse sources.

• The Journal of the Petrological Society of Korea
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• v.12 no.3
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• pp.135-153
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• 2003

In order to understand its origin and petrogenesis, petrochemical studies of major, trace elements, REE, and stable isotopes of oxygen and carbon from the Hongcheon Fe-REE deposits have been investigated. The Hongcheon Fe-REE deposit intruding into Precambrian metasedimentary rocks consists of magnetite, various carbonates such as ankerite, siderite, magnesite and strontianite, monazite, aegirine-augite, Na-amphibole, and sulfides. Compared with major elements abundances of typical ferro-carbonatites, the Hongcheon Fe-REE deposit is enriched in FeO and depleted in CaO with increasing of $SiO_2$, where $TiO_2$and $A1_2O_3$increased and CaO, FeO, MgO and $P_2O_5$ are slightly decreased, but those are rather scattered and their trends are somewhat ambiguous. V Ni, U and Rb slightly increasing with of $SiO_2$increase and scattering or no trends of other detected elements. Nb, Zr and Zn are depleted then the abundances of typical ferro-carbonatites (Woolley and Kempe, 1989). In rare earth elements a large enrichment of total REE (maximum 14.8 wt%) and LREE relative to chondrites and HREE depleted more then the values of ferro-carbontites therefore La/Lu ratios shows large abundances (max. 16,197). The results of stable isotopes of O and C from minerals of ankerite and strontianite and whole rocks represent studied rocks are from igneous carbonatitic melts. Although petrochemical characteristics of the Hongcheon Fe-REE deposits are somewhat different from normal ferro-carbonatites from the world, this discrepancy suggests another conclusion that petrochemical characteristic of the studied Fe-REE mineralized rocks are similar to those of phoscorites from Kovdor, Russia and Sokli, Finland showing the same petrochemical compositions described above.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4643-4651
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• 2013

In this study, we have surveyed the new technologies in the cryogenic distillation of ITER, equilibrium reactors and helium refrigeration cycle contained in the isotope separation system (ISS). We also have collected thermodynamic and transport properties for $H_2$, HD, $D_2$, HT, DT and $T_2$ components of which properties are not built in a general purpose chemical process simulators such as Aspen Plus and PRO/II with PROVISION. Verification works have been performed to compare between literature data and simulation results. For the simulation of ISS involving six hydrogen isotope components, four distillation columns and two equilibrium reactors are used for the separation of $D_2$ and DT from $T_2$.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.93-102
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• 2007

The runoff characteristics of organic matter in turbid water were investigated in eleven tributary streams of the Han River system, Korea. The flow-weighted event mean concentrations of organic matter ranged from 1.5 to 3.2 mg $L^{-1}$ of DOM and 2.2 of 29.1 mg $L^{-1}$ of POM, respectively. The SUVA value which reflects the proportion of humic substance in organic matters was higher during the rainfall season, meaning that the runoff of refractory form increase in this period. Stable carbon isotope ratios of both POM and DOM were different among streams, which reflect the sources of organic matter. DOM isotope ratios were less depleted of $^{13}C$ than that of POM by approximately 1 to $2%_{\circ}$ ${\delta}^{13}C$ of the several turbid streams (the Mandae Stream, the Jawoon Stream, and the Daegi stream) were heavier than those of clear streams. ${\delta}^{13}C$ values in the turbid upstream tributaries were similar to those of downstream reaches (such as the Soyang River, the Sum River, and the Seo River). From the ${\delta}^{13}C$ analysis of POM it could be calculated that $C_4$ pathway contributed approximately 15.9 to 23.6% of organic matter in several turbid upstream sites, and over 20% in the three sites of large downstream reaches. On the contrary it contributed only 9.1 to 12.8% in clear streams of forest watersheds. In the Soyang River, $C_4$ pathway organic matter contributed 8.8% of the DOM pool.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1681-1685
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• 2010

우리나라 가축분뇨 발생량 중 약 10%만이 정화방류 및 공공처리에 의해 처리되고 있으며 2012년 이후 해양투기가 전면 금지됨에 따라 가축분뇨의 자원화 및 육상처리에 대한 대책이 절실한 실정이다. 이에 최근 이에 대한 대안 중 하나로 산림지 및 조림지역에 축산분뇨 액비를 처리하자는 대안이 대두되고 있다. 가축분뇨로부터 생산된 액비는 화학비료를 대신하여 자연순환농업에 효과적으로 사용될 수 있으며, 가축분뇨를 비료로 재활용할 수 있는 장점이 있는 반면, 시용량이나 시용 시기, 시용대상에 따라 환경, 특히 수질 및 지하수에 미치는 영향이 있을 수 있다. 따라서, 저농도액비 시용이 지하수 수질에 미치는 영향 및 환경영향평가, 영향성분 수지의 균형여부 등에 대한 모니터링과 분석이 필요하다. 따라서 본 연구에서는 백합나무 조림지인 바이오순환림에 저농도액비를 시용하였을 때 지하수에 미치는 영향을 살펴보기 위하여 매주 지하수의 수질 모니터링을 실시하였으며, 이를 수질항목에 대하여 분석한 후 액비시용에 따른 수질변화를 제시하였으며, 지하수 오염여부를 결정하는 대표항목인 질산성질소의 오염원을 판별하기 위하여 질소 동위원소비를 분석하였다. 추후 지속적인 지하수 모니터링을 통하여 다양한 수질항목에 대한 분석이 이루어진다면 바이오순환림을 비롯한 산림지에서의 저농도액비 시용에 따른 수질 영향 평가 및 모형 구축의 기초자료로 활용될 수 있을 것으로 판단된다.

• Economic and Environmental Geology
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• v.45 no.1
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• pp.23-30
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• 2012

Major ions and nitrogen isotopic analyses were performed to determine the geochemical characters and to identify the source of nitrate of the shallow groundwater around agricultural field in the Youngdong area. The pH value of groundwater ranges from 60. to 8.2 (pH 7.2, mean). The average of EC, Eh and DO is 369 ${\mu}S/cm$ (70~729 ${\mu}S/cm$), 165.6 mV (29~383.2 mV), 4.3 mg/L (1.8~8.0 mg/L) respectively. The ion concentraion of groundwater was in the order of $Ca^{2+}$>$Na^{2+}$>$Mg^{2+}$>$K^{2+}$ and ${HCO_3}^-$>${NO_3}^-$>${SO_4}^{2-}$>$Cl^-$>$F^-$. Most of groundwater is Ca-$HCO_3$ type. The groundwater was affected by water-rock interaction in the shallow depth. Some groundwater is Ca-Cl or Na-$HCO_3$ (2.5%) type that was due to agricultural activities. The $NO_3$_N concetration of grondwater range from 10.2 mg/l to 26.9 mg/l, which show that this area is under nitrate pollution. ${\delta}^{15}N-NO_3$ value of the groundwater is the origins of are a combination of animal wastes and man-made fertilizers.

• Economic and Environmental Geology
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• v.38 no.4 s.173
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• pp.463-479
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• 2005

The Sr and Pb isotopic ratios and chemical composition were measured for atmospheric bulk deposition samples collected in the Jeonju, Gunsan and Namweon areas over a period of one year. Acidity of deposition ranged pH $4\~7$ with little higher in dry season, and around pH 5.0 in rainy season. The EC and TDS of rainy season was low showing dilution effect, and increased during dry season. Sulfate $(SO_4)\;and\;NO_3$ are atmospheric aerosols largely of anthropogenic origin in winter. Sodium was concentrated in winter deposition, Ca was concentrated in spring to summer deposition. Namweon has lower EC and TDS than those of other, and Jeonju has higher. Namweon was concentrated in $HCO_3$ and Cunsan was concentrated in Cl. Aluminium, Cu, and Zn show good correlation index with TDS, indicating of their origin atmospheric. $^{87}Sr/^{86}Sr$ ratios of bulk deposition ranged from 0.7109 to 0.7128. The isotopic variations are correlated with mixing of isotopic compositions of local soils, road deposit and biogenic aerosol. In order to constrain further the origin of aerosols in rainwater, it will be necessary to collect additional Sr isotopic data for aerosols. Lead isotope ratios for all areas were similar and belonged to Pb isotope ratios of Seoul's aerosols, but little different with Beijing's aerosols. It showing that Pb in the Korea mainly derived from the gasoline combustion, not exclusively from the Beijing.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.707-716
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• 2005

Organic geochemical analyses including Rock-Eval pyrolysis, elemental analysis and stable carbon isotope analysis were performed to evaluate the characteristics of organic matter in the ODP Leg 127 Site 794A sediments and to understand paleoceanographic changes. Based on the TOC contents, C/N ratio, HI vs. OI, $\delta^{13}C_{org}$ and C/S ratio, results imply that dark layers containing a large amount of terrigenous organic matter were deposited under the suboxic/anoxic conditions, whereas the light layers containing largely marine organic matter were deposited under the oxic conditions. These results indicate that increasing surface-productivity by the input of a large amount of terrigenous organic matter from adjacent continent led to the deposition of dark layers during the interglacial highstands, whereas marine primary production and dilution caused by Kosa from the China desert area led to the deposition of light layers with the decreased to terrigenous organic matter during the glacial lowstands.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.419-423
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• 2006

유류누출지역의 수리지질, 수리지화학 및 미생물 분석을 통하여 지층특성이 지하수 흐름, 수질 및 미생물 특성에 미치는 영향을 고찰한 결과 지표에서 심도 $1.8{\sim}3.5m$ 구간에 수십 cm에서 2m 정도의 두께를 갖는 투수성이 상대적으로 양호한 지층이 존재함을 확인할 수 있었다. 이러한 지층의 존재에 의하여 상하부의 지하수대의 수두차이가 현저함을 관측하였으며 유류 수송관에서 누출된 유류가 이 투수성 지층을 따라 이동하여 이 구간의 토양 및 지하수가 오염되었다고 판단할 수 있다. 지하수 수질은 이러한 지층의 특성에 따라 다른 이온성분 및 동위원소 특징을 보여주었으며 이는 다변량통계분석에 의해서도 확인할 수 있었다. 미생물 DGGE 분석결과 역시 유사한 특징을 보여주어 이러한 수리지화학, 수리지질 및 미생물 특징이 서로 밀접한 상관성을 보여줌을 확인할 수 있었다.