• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.99-106
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• 1998

Two kinds of carrageenan were extracted from red seaweeds, Tichocarpus crinitus, collected in The Peter the Great Bay of Russia on August, 1996. One is KC1-insoluble carrageenan and another is KC1-soluble carrageenan. The yield of KC1-insoluble carrageenan was 17.15%, which is composed of 18.06% total sulfate, 5.61% protein, 3.51% K+, 0.49% Na+, 1.66% Ca2+, 54.26% galactose, 4.68% xylose, trace of mannose and glucose. The yield of KC1-soluble carrageenan was 3.52%, which is composed of 24.06% total sulfate, 5.2% protein, 5.32% K+, 0.16% Na+, 2.80% Ca2+, 33.54% galactose, 5.48% xylose, 4.32% mannose, trace of glucose. But rhamnose was not detected in both case. FT-IR spectrum showed that the KC1-insoluble carrageenan was kappa-type carrageenan and that KC1-soluble carrageenan was lambda, iota hybrid-type carrageenan. KC1-insoluble carrageenan was very weakly formation the gel compared with KC1-insoluble carrageenan from other red seaweeds. So we investigated viscosity. Both type carrageenan was stable in the temperature until 9$0^{\circ}C$, 1 hr. The viscosity of the solution of KC1-insoluble carrageenan was increased to about two folds by K+, but was not changed by Ca2+. The viscosity of the solution of KC1-soluble carrageenan was reduced by K+ and Ca2+. Both of them was stabilized in alkali but was reduced in comparison with acid conditions. In this study, both carrageenan was expected as thickening agent than gelling agent for food additives.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.635-649
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• 2007

Geochemical composition, stable isotopes $({\delta}^{18}O,\;{\delta}D,\;{\delta}^{34}S)$ and noble gases(He, Ne and Ar) of nine hot spring water and three groundwater for five hot springs(Jukam, Hwasun, Dokog, Jirisan, Beunsan) from the Honam area were analyzed to investigate the hydrogeochemical characteristics and the hydrogeochemical evolution of the hot spring waters, and to interpret the source of sulfur, helium and argon dissolved in the hot spring waters. The hot spring waters show low water temperature ranging from 23.0 to $30.5^{\circ}C$ and alkaline characteristics of pH 7.67 to 9.98. Electrical conductivity of hot spring waters is $153{\sim}746{\mu}S/cm$. Groundwaters in this area were characterized by the acidic to neutral pH range$(5.85{\sim}7.21)$, the wide electrical conductivity range $(44{\sim}165{\mu}S/cm)$. The geochemical compositions of hot spring and groundwaters can be divided into three water types: (1) $Na-HCO_3$ water type, (2) Na-Cl water type and (3) $Ca-HCO_3$ water type. The hot spring water of $Ca-HCO_3$ water type in early stage have been evolved through $Ca(Na)-HCO_3$ water type into $Na-HCO_3$ type in final stage. In particular, Jurim alkaline(pH 9.98) hot spring water plotted at the end point of $Na-HCO_3$ type in the Piper diagram is likely to arrive into the final stage in geochemical evolution process. Hydrogen and oxygen isotopic data of the hot spring water samples indicate that the hot spring waters originated from the local meteoric water showing latitude and altitude effects. The ${\delta}^{34}S$ value for sulfate of the hot spring waters varies widely from 0.5 to $25.9%o$. The sulfur source of most hot spring waters in this area is igneous origin. However, The ${\delta}^{34}S$ also indicates the sulfur of JR1 hot water is originated from marine sulfur which might be derived ken ancient seawater sulfates. The $^3He/^4He\;and\;^4He/^{20}Ne$ ratios of the hot spring waters range from $0.0143{\times}10^{-6}\;to\;0.407{\times}10^{-6}\;and\;6.49{\sim}584{\times}10^{-6}$, respectively. The hot spring waters are plotted on the mixing line between air and crustal components. It means that the He gas in the hot spring waters was mainly originated from crustal sources. However, the JR1 hot spring water show a little mixing ratio of the helium gas of mantle source. The $^{40}Ar/^{36}Ar$ ratios of hot spring water are in the range from $292.3{\times}10^{-6}\;to\;304.1{\times}10^{-6}$, implying the atmospheric argon source.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.107-107
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• 2015

최근 기후변화로 인한 강우강도 증대, 산업화에 따른 토지개발 등으로 인하여 다량의 점착성 부유사(Cohesive Sediments)가 하천, 호소 등 수자원 환경으로 유입되고 있다. 점착성 부유사는 하천, 호소의 난류 조건에 따라 부유하거나 혹은 응집, 침전하여 하상 저니층을 형성한다. 부유사, 미생물 및 각종 유기입자가 포함된 하상 저니층은 검은색으로 외관상 보기 좋지 않을 뿐 아니라, 혐기성상태에서 부패하여 수생태계의 건강성을 해치게 된다. 또한 미세 부유사 및 미생물 입자는 각종 중금속, 유기오염물질을 흡착하고, 조건에 따라 재용출할 수 있는 저장매체로 작용하기 때문에 수자원환경에 미치는 영향이 아주 크다. 특히, 수중 미생물(조류) 작용에 의해 생성되는 EPS (Extracellular Polymeric Substances)는 부유사 및 미생물 입자들을 서로 엉겨 붙게 하여, 부유사-미생물 혼합 응집체 및 저니층 형성을 가속화하게 된다. 본 연구에서는 EPS가 부유사 응집에 미치는 영향을 파악하기 위하여, Xanthan Gum (Sigma-Aldrich, USA)을 EPS의 지표 물질로 사용하고, Kaolinite(Sigma-Aldrich, USA)를 수자원환경에 존재하는 대표적인 부유사로 사용하여 응집실험(Jar Test)을 수행하였다. 이온농도가 응집에 미치는 영향을 파악하기 위하여 수체 이온농도를 0.0001M NaCl, 0.001M NaCl, 0.01M NaCl, 그리고 0.001M NaCl + 0.1mg/L $Ca^{2+}$, 0.001M NaCl + 0.5mg/L $Ca^{2+}$, 0.001M NaCl + 1.0 mg/L $Ca^{2+}$으로 보정하여 응집실험을 수행하였다. 250 rpm 급속 교반 1븐, 50 rpm 완속교반 5시간, 침잔 1시간 후 응집체를 채취하여 응집체 이미지 분석을 통해 응집체 크기 및 형상을 측정하였고, 수표면 2 cm 지점에서 상등액을 채수하여 잔류 고형물 농도 분석을 실시하였다. 응집실험을 통하여 다음과 같은 결과를 도출하였다.. 낮은 이온농도의 경우, EPS가 큰 고분자 구조체에 부유 입자들이 엮어 응집되는 Sweeping Flocculation의 특징을 나타내었다. 하지만, 이온농도가 높아질수록 경우, EPS 고분자 구조체 내부 반발력이 감소하여 크기가 축소되고, 이에 따라 부유 입자 표면에 패치 형태로 흡착되었다. EPS가 패치형태로 입자에 흡착한 경우, 응집제 농도 증가에 따라 응집능 최적점이 형성되고, 이후 표면하전 역전이나 Steric Stabilization에 의해 응집능이 저감되는 형태를 나타낸다. 따라서,수중이온농도가 EPS의 사슬형 고분자 응집제의 크기, 형태(Morphology)를 결정하고, 더 나아가 응집능을 결정하는 중요한 인자로 나타났다. 따라서, 후속 연구를 통하여 생체고분자물질의 크기 및 형태 변화, 이에 따른 응집능변화를 면밀히 연구하고자 한다.

• Journal of the Mineralogical Society of Korea
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• v.15 no.3
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• pp.147-159
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• 2002

Weathered bentonites occcur as surficial alterations of some domestic bentonite deposits in the Tertiary formations, with the thickness of less than about 50 cm, along naturally-formed weathering surface with slopping in gentle. 7 $\AA$-halloysite was found together with montmorillonite in the weathered bentonite. Compared to normal bentonite, the weathered one is generally more clay-rich and contains little amounts of original rock-forming minerals and residues. In the electron microscopy, fine-scale occurrence of the clay minerals tends to be somewhat discrete and segregated rather than closely associated. h curled margin of montmorillonite lamella is deformed to become obtuse in the weathered bentonite. Halloysite occurs as acicular to tubular crystals with the length of less than 2 $\mu$m and the width of about 0.3 $\mu$m, which commonly forms bundle-shaped aggregates. Electron microscopic observations on the fine-scale occurrence and texture of the wtathered bentonites indicate that the clay mineral transition from montmorillonite to halloysite has undergone without accompanying any intermediate phases of both clay minerals such as a mixed-layered type (M/H). The alteration reaction between these two clay minerals probably took place in the form of dissolution and precipitation mechanism in oxidation condition. An intense chemical leaching of SiO$_2$, Na, K and Ca might occur during the alteration reaction, forming a lot of dissolution cavity and residual concentration of A1$_2$O$_3$ and Fe, relatively. As the result of the chemical change, a fsvorable condition for halloysite formation seemed to be provided.

• Economic and Environmental Geology
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• v.36 no.6
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• pp.441-455
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• 2003

The most common water types are found to be Ca-$HCO_3$, Ca-Na-$HCO_3$ and Ca-Na-$HCO_3$-Cl in Gwangju groundwater. Groundwater near the Gwangju stream are characterized Ca-Cl water type, with over 50 mg/L of C1- and 400 ${\mu}$S/cm of EC. The systematic variation of $Cl^-$, $HCO_3^-$,- EC and ${\gamma}^{18}O$ values in groundwater with distance away from drainages is caused by streamwater infiltration. Stable isotope data indicate that ${\gamma}$D and ${\gamma}^{18}O$ values of groundwaters near drainages were enriched by evaporation effect, showing a equation of ${\gamma}$D=7. 1${\times}{\gamma}^{18}O$-1. ${\gamma}^{18}O$ values over -6${\textperthansand}$ are anomalous in the unconfined groundwater zones, which are influenced by the local surface water enriched in $^{18}O$ composition. Groundwater in highland shows remarkably light ${\gamma}^{18}O$ values below -8$\textperthousand$. The infiltration of streamwater is dominant in unconfined alluvium aquifer near drainages. ${\gamma}^{13}$CDIC values (-17.6∼-15.2$\textperthousand$) of groundwaters near drainages revealed that dissolved inorganic carbon (DIC) is predominantly originated from natural soil-derived $CO_2$. ${\gamma}^{15}N$ and ${\gamma}^{18}O$ values of nitrate are 0∼17.0${\textperthansand}$ and 6.6∼17.4${\textperthansand}$, respectively. Relationship between ${\gamma}^{15}N$ and ${\gamma}^{18}O$ shows a systematic isotopic fractionation caused by denitrification of 40∼60%, suggesting that the major source of groundwater nitrate originated from nitrate of soils, and mixing nitrate of soil and sewage or manure.

• 한국해양학회지
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• v.24 no.3
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• pp.132-147
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• 1989

A total of 83 surface sediments and 55 sea water samples, collected from the southwestern sea of Cheju Island, were analyzed in order to understand their textural characteristics, geochemical composition and the clay mineralogical features. The sediments were subdivided into ten textural classes, namely clayey sand, slightly gravelly muddy sand, sandy clay, clay and mud. The coarse and fine-grained mixed sediments are distributed in the northern part and around the Island, whereas the fine-grained deposits are mainly distributed in the central and southern parts of the study area; small scale mud patches are distributed in the southwestern and northern parts of Cheju Island. The high concentration of total suspended matter in study area gradually increase toward the southwestern and northwestern offshore area. The concentration of geochemical elements is as follow: the content of Mn, Al, Zn, Cr, Cu and Sn increase toward the southern part which is covered mainly with fine-grained deoposits, whereas the content of Ca, Mg and Ag is higher in the northern area; the elements such as Ni, Na, Fe and Pb are more concentrated relatively in muddy deposits rather than in sandy sediments. The light minerals such as Na-Ca feldspars show a high content around the Socotra Rock, toward the Soheugsan and Cheju Islands, but the K-feldspars are relatively high around the Cheju Island. It was noticed that the provenance of these sediments is partly influenced by the geological characteristics near the island. X-ray diffractogram for clay minerals from the southeastern mud patch and around the Soheugsan Island shows the diagnostic calcite peak indicating that the greater part of these clay fraction may have been derived from present and ancient Hwangho River. The high concentration of smectite in the northern part near the Cheju and around the Soheugsan Islands, eastern side of Socotra Rock probably result from supplies smectite altered from volcanic materials distributed in the Cheju Island and Socotra Rock, whereas the samples near the Chuja and northern parts of the Cheju Island contain weak calcite peak and high concentration of kaolinite and chlorite which is closely related to the geolgical characteristics on the adjacenting land area.

• Economic and Environmental Geology
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• v.31 no.3
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• pp.201-213
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• 1998

From the Jungwon and Munkyeong areas which are among the famous producers of the carbonate-type groundwaters in Korea, various kinds of natural waters (deep groundwater, shallow groundwater and surface water) were collected between 1996 and 1997 and were studied for hydrogeochemical and environmental isotope (${\delta}^{34}S_{so4}$, ${\delta}^{18}O$, ${\delta}D$)systematics. Two types of deep groundwaters (carbonate type and alkali type) occur together in the two areas, and each shows distinct hydrogeochemical and environmental isotope characteristics. The carbonate type waters show the hydrochemical feature of the 'calcium(-sodium)-bicarbonate(-sulfate) type', whereas the alkali type water of the 'sodium-bicarbonate type'. The former type waters are characterized by lower pH, higher Eh, and higher amounts of dissolved ions (especialJy, $Ca^{2+}$, $Na^{+}$, $Mg^{2+}$, $HCO_3{^-}$ and $SO_4{^{2-}}$). Two types of deep groundwaters are all saturated or supersaturated with respect to calcite. Two types of deep groundwaters were both derived from pre-thermonuclear (about more than 40 years old) meteoric waters (with lighter 0 and H isotope data than younger waters, i.e., shallow cold groundwaters and surface waters) which evolved through prolonged water-rock interaction. Based on the geologic setting, water chemistry, and environmental isotope data, however, each of these two different types of deep groundwaters represents distinct hydrologic and hydrogeochemical evolution at depths. The carbonate type groundwaters were formed through mixing with acidic waters that were derived from dissolution of pyrites in hydrothermal vein ores (for the Jungwon area water) or in anthracite coal beds (for the Munkyeong area water). If the deeply percolating meteoric waters did not meet pyrites during the circulation, only the alkali type groundwaters would form. This hydrologic and hydrogeochemical model may be successfully applied to the other carbonate type groundwaters in Korea.

• Economic and Environmental Geology
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• v.42 no.6
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• pp.541-548
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• 2009

The Dongrae thermal water area located at the southeastern marginal part of the Korean Peninsula is one of the oldest hot springs in Korea. The Dongrae thermal water shows Na-Cl type of water chemistry, whereas the shallow cold groundwater is Ca(-Na)-$HCO_3$ type. In this paper, we discuss the age of the Dongrae hot spring, i.e. groundwater cycle among meteoric water-surface water-shallow groundwater-hot spring water. The $^{87}Sr/^{86}Sr$ ratios of the thermal water in Dongrae area range from 0.705663 to 0.705688 and are lower than those of groundwater, surface water and rain water as well as aquifer bearing granite. These Sr isotopic signatures in the Dongrae thermal water indicate that the circulation rate between thermal water and current meteoric water including groundwater, surface water and rain water in the Dongrae area should be very slow. The $^{14}C$ age of the Dongrae hot spring water range from $1,271{\pm}36$ BP(before present) to $2,467{\pm}36$ BP whereas that of the shallow groundwater is $-495{\pm}33$ BP. This suggests that the period of groundwater cycle among meteoric water, surface water, shallow groundwater and hot spring should be more than 1,270 years. Then, it also indicates that the present Dongrae hot spring may be a mixed water between the old thermal water heated for at least 1,270 years and the present shallow cold groundwater.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.253-260
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• 2005

Salt accumulation in the plastic film house soils under continuous cultivation condition causes problems such as salt damages to plants, nitrate accumulation in vegetables, groundwater contamination, etc. due to excess application of fertilizers. Objective of this research was to find an optimum adsorbent to reduce salt concentration in the soil solution of plastic film house soils, where crop injuries have been observed due to the salt accumulation. The soils were significantly high in available P $(1,431{\sim}6,516mg\;kg^{-1}),\;NO_3-N\;(117.60{\sim}395.73mg\;kg^{-1})$, exchangeable Ca $(4.06{\sim}11.07\;cmol_c\;kg^{-1})$ and Mg $(2.59{\sim}18.76\;cmol_c\;kg^{-1})$, as compared to those of the average upland soils in Korea. Soils were treated with each of adsorbent such as ion-exchange resin, zeolite, rice bran, etc. at 2% level and prepared into saturated-paste samples. After equilibrium, soil solution was vacuum-extracted from the soil and measured for changes of the pH, EC, and concentrations of $Ca^{2+},\;Mg^{2+},\;K^+,\;Na^+,\;{NH_4}^+,\;{PO_4}^{3-}\;and\;{NO_3}^-$. Rice bran effectively removed ${PO_4}^{3-}\;and\;{NO_3}^-$ in the soil solution up to 100%. Efficiency was decreased in the orders of rice bran > ion-exchange resin > zeolite. Removal efficiencies of zeolite and ion-exchange resin for $Ca^{2+}$ were ranged from 1 to 65% and from 7 to 61%, respectively. Ion-exchange resin was also effective for removing $Mg^{2+},\;K^+,\;Na^+,\;and\;{NH_4}^+$. Overall results demonstrated that rice bran and ion-exchange resin could be applicable for salt accumulated soil to remove the respective anion and cation.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.734-741
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• 1998

Electrode characteristics were studied in the interface between sample solutions and $K^+$ ion selective PVC membrane electrodes containing neutral carriers, dibenzo-18-crown-6(D18Cr6) and valinomycin(Val). The effect of doping of base electrolytes, the chemical structure and the content of carrier, variation of plasticizer, membrane thickness, and concentration variation of sample solution on the response characteristics of electrode such as the measured Nernstian slope, the detection limit, the linear response range, and potentiometric selectivity coefficients, were studied. In order to synthesize the membrane D18Cr6 and Val as neutral carriers were used, and complex between the carrier and $K^+$ ions were used as active materials. PVC membrane electrodes were made of plasticizers (DBP, DOS, and DBS), the base electrolyte[potassium tetraphenylborate(KTPB)], and solvent(THF). The chemical structure of carrier D18Cr6 was best for electrode and ideal electrode characteristics were appeared especially in case of doping of TPB. The optimum carrier content was about 3.23 wt % in case of D18Cr6 and Val. DBP was best as a plasticizer. As membrane thickness decreased the electrode characteristics was improved. But its characteristics were lowered below the optimum membrane thickness because of the elution of carrier, deterioration of membrane strength, etc. In the case of D18Cr6, the selectivity coefficients by the mixed solution method for the $K^+$ ion were in the order of $NH_4{^+}>Ca^{2+}>Mg^{2+}>Na^+$.