• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.1
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• pp.1-11
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• 2010

In order to understand the biological environmental characteristics with temporal variations of the physico-chemical factors in 2012 Yeosu Expo site of Korea, we investigated at one station, once per week, from April 2006 to December 2007. The surface water temperature ranged from 6.8 to $27.8^{\circ}C$ and the bottom water temperature ranged from 6.3 to 25.9 $25.9^{\circ}C$. The salinity varied from 12.8 to 33.0 psu in the surface water and from 25.2 to 33.6 psu in the bottom water. A strong halocline was observed between the surface and bottom layers in the summer when a rapid decrease of salinity coincided with heavy rainfall. The DIN concentration ranged from 1.36 to $82.7{\mu}M$ in the surface water and from 0.82 to $25.2{\mu}M$ in the bottom water. Phosphate concentration varied from 0.06 to $2.13{\mu}M$ in the surface water and from 0.07 to $1.38{\mu}M$ in the bottom water. Silicate was $1.68-52.0{\mu}M$ in the surface water and $1.37-30.7{\mu}M$ in the bottom water. The nutrient concentrations were generally high during heavy rainfalls and low water temperature periods, and considerably decreased in spring and autumn. The N/P ratio ranged from 4.43 to 325 in the surface water and from 3.8 to 321 in the bottom water. It increased rapidly during the heavy rainfall season and remained at a value of approximately 16 in other periods. The chlorophyll a concentration ranged from 0.46 to $65.0{\mu}g$ $L^{-1}$ in the surface water and from 0.71 to $15.0{\mu}g$ $L^{-1}$ in the bottom water. $Chl-{\alpha}$ concentration remained low in periods of low water temperature, however rapidly increased in periods of high water temperature. From the results of principal component analysis (PCA) and multiple regression analysis (MRA), we conclude that temporal variations of physico-chemical and biological factors were greatly affected by the influx of fresh water, and that nutrients were well controlled by their uptake and assimilation by phytoplankton. Also, during the low water temperature periods, environmental structure in this study site was affected by recycled nutrients through nutrient cycling and mineralization.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.523-535
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• 1994

The strata-bound type iron ore bodies in the Chungju mine are interbedded with metamorphic rocks which are intruded by Mesozoic granitic rocks. The iron ore deposit occurs as layer or lens shape which are concordant with the metamorphic rocks. The iron ore is classified into banded and massive types based on the mode of texture and occurrence. Grain size and iron-oxides tend to become coarser toward massive ore than banded ore. Banded ores commonly contain internal layers defined by alternating magnetite- rich, hematite-rich, magnetite-hematite, and quartz-rich mesobands. The banded iron ore consists of hematite, magnetite, quartz, feldspar, and minor amounts of biotite, muscovite, chlorite, carbonates, epidote, allanite, and zircon. Massive ores which are characterized by high magnetite content occur in contact of granitic rocks. The massive iron ores consist mostly of magnetite and quartz, with minor amounts of hematite, pyrite, microcline, biotite, muscovite, chlorite, carbonates, epidote, allanite and zircon. Magnetite from banded and massive ores is almost pure $Fe_3O_4$ in composition, including 0.14 to 0.27 wt.% MnO and 0.10 to 0.15 wt.% MnO, respectively. Hematite of the ore contains 0.87 to 1.27 wt.% $TiO_2$ in banded ore and 3.44 to 6.96 wt.% $TiO_2$ in massive ore, respectively. Biotite shows a little compositional variation depending on ore types. Biotite of the banded ore has lower FeO, $TiO_2$ and $Al_2O_3$, and higher MgO and $SiO_2$ than the massive ore. The modes of occurrence and petrography of ore implies that massive ores might have been formed either under more reducing environments or higher temperature condition than banded ore. Banded ores might represent early episode of iron enrichment due to regional metamorphism. Massive ores might be related to the contact metamorphism resulting from late granitic intrusion.

• Economic and Environmental Geology
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• v.49 no.1
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• pp.1-11
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• 2016

Chrysotile is well known as a fibrous mineral in serpentinite by the previous studies in S. Korea. Previous studies in other countries showed that antigorite also occurred as asbestiform and harmful to humans. Therefore, the objective of this study was to investigate types and characteristics of fibrous serpentine minerals occurred in serpentinite in Hongseong, Chungnam and Gapyeong, Gyeonggi in S. Korea. XRD, SEM-EDS, PLM and EPMA mapping analyses were used to examine the occurrence and formation mechanism of serpentine minerals. Serpentinization partially occurred in amphibole-schist and calc-schist at two study sites, Hongseong, Chungnam and Gapyeong, Gyeonggi, respectively. Both chrysotile and antigorite occurred as a fibrous mineral at Hongseong site, but chrysotile occurred as a fibrous mineral at Gapyeong site. Based on PLM analysis with dispersion staining, the chrysotile was observed horizontally magenta and vertically blue colors. The antigorite appeared as horizontally gold to golden magenta and vertically blue magenta colors under central stop dispersion staining objective(DSO). PLM and SEM analyses showed the fibrous minerals were formed from plate form of serpentine minerals or by hydrothermal alternation of primary minerals. The EPMA mapping showed that Mg contents in chrysotile is relatively higher than that in antigorite while Si and O contents in antigorite is higher than them in chrysotile. However, more studies are necessary to know the exact variation in chemical composition of chrysotile and antigorite. These results indicate that even though asbestiform antigorite found associated with asbestos chrysotile in serpentinites, the fibrous antigorite can be distinguished from chrysotile by different dispersion staining colors.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.625-636
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• 2010

The geophysical characteristics and geological structure of the northeastern part of the Ulleung Basin were investigated from interpretation of geophysical data including gravity, magnetic, bathymetry data, and seismic data. Relative correction was applied to reduce errors between sets of gravity and magnetic data, obtained at different times and by different equipments. The northeastern margin of the Ulleung Basin is characterized by complicated morphology consisting of volcanic islands (Ulleungdo and Dokdo), the Dokdo seamounts, and a deep pathway (Korea Gap) with the maximum depth of -2500 m. Free-air anomalies generally reflect the topography effect. There are high anomalies over the volcanic islands and the Dokdo seamounts. Except local anomalous zones of volcanic edifices, the gradual increasing of the Bouguer anomalies from the Oki Bank toward the Ulleung Basin and the Korea Gap is related to higher mantle level and denser crust in the central of the Ulleung Basin. Complicated magnetic anomalies in the study area occur over volcanic islands and seamounts. The power spectrum analysis of the Bouguer anomalies indicates that the depth to the averaged Moho discontinuity is -16.1 km. The inversion of the Bouguer anomaly shows that the Moho depth under the Korea Gap is about -16~17 km and the Moho depths towards the Oki Bank and the northwestern part of Ulleung Island are gradually deeper. The inversion result suggests that the crust of the Ulleung Basin is thicker than normal oceanic crusts. The result of 20 gravity modeling is in good agreement with the results of the power spectrum analysis and the inversion of the Bouguer anomaly. Except the volcanic edifices, the main pattern of magnetization distribution shows lineation in NE-SW. The inversion results, the 2D gravity modeling, and the magnetization distribution support possible NE-SW spreading of the Ulleung Basin proposed by other papers.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.589-601
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• 2010

Recently it has been frequently reported arsenic contamination of geologic origin in groundwater. The iron-impregnated ranular activated carbon (Fe-GAC) was developed for effective removal of arsenic from groundwater n the study. Fe-GACs were prepared by impregnating iron compounds into a supporting medium (GAC) with 0.05 M iron nitrate solution. The materials were used in arsenic adsorption isotherm tests to know the effect of iron impregnation time, batch kinetic tests to understand the influence of pH, and column tests to evaluate for the preliminary operation of water treatment system. The results showed that the minimum twelve hours of impregnation time were required for making the Fe-GAC with sufficient iron content for arsenic removal, confirmed by a high arsenic adsorption capacity evaluated in the isotherm tests. Most of the impregnated iron compounds were iron hydroxynitrate $Fe_4(OH)_{11}NO_3{\cdot}2H_2O$ but a mall quantity of hematite was also identified in X-ray diffraction(XRD) analysis. The batch isotherms of Fe-GAC for arsenic adsorption were well explained by Langmuir than Freundlich model and the iron contents of Fe-GAC have positive linear correlations on logarithmic plots with Freundlich distribution coefficients ($K_F$ and Langmuir maximum adsorption capacities ($Q_m$. The results of kinetic experiments suggested hat Fe-GAC had he excellent arsenic adsorption capacities regardless of all pH conditions except for pH 11 and could be used a promising adsorbents for groundwater arsenic removal considering the general groundwater pH range of 6-8. The pseudo-second order model, based on the assumption that the ate-limiting step might be chemisorption, provided the best correlation of the kinetic experimental data and explained the arsenic adsorption system f Fe-GAC. The column test was conducted to valuate the feasibility of Fe-GAC use and the operation parameters in arsenic groundwater treatment system. The parameters obtained from the column test were the retardation actor of 482.4 and the distribution coefficient of 581.1 L/mg which were similar values of 511.5-592.5 L/mg acquired from Freundlich batch isotherm model. The results of this study suggested that Fe-GAC could be used as promising adsorbent of arsenic removal in a small groundwater supply system with water treatment facility.

• Economic and Environmental Geology
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• v.47 no.6
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• pp.611-623
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• 2014

The alluvial aquifer, widely developed near the four major rivers such as Nakdong River, can be used effectively for groundwater artificial recharge and is expected to be the future water resources in Korea. This study is aimed at examining the impact of repeatedly injected river water into the riverside alluvial aquifer on injection rate or efficiency in its system at Changweon area. For this, injection tests were performed two times, first on June 19 and second on September 25 through October 9, 2013, and the mixing ratios of river water to groundwater were used as the tool to compare the efficiency of injection. The mixing ratios were evaluated by using electrical conductivities of injected river water (average $EC=303{\mu}S/cm$) and groundwater ($EC{\fallingdotseq}6,000{\mu}S/cm$) measured at 20 m depth of four observation wells installed 10 m apart from each injection well. The result shows the remarkable differences on two respects. First, in some observation well, detection time for incipient injection effect during $2^{nd}$ injection test was shown to be much slower than that of $1^{st}$ injection test. Second, the hourly increasing rate of mixing ratios in $2^{nd}$ test was revealed to be reduced much more than that of $1^{st}$ test. This means that the efficiency of injection was badly deteriorated by only 1,210 minute injection work. Therefore, injection water needs to be adequately treated beforehand and repeated pumping work and/or resting phase is needed afterwards. To a certain extent, the improvement of water quality in saline aquifer was verified in this system by injection tests.

• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.121-129
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• 2014

This study was carried out to investigate the quality characteristics of protein enriched fermented milk made with whey and soybean flour. Protein-enriched fermented milk was prepared as follows: Soybean flour was added before fermentation. No synthetic aroma was added. The fermentation starter culture was ABT-4 (Chr. Hansen). Whey protein was added after fermentation. Sensory evaluation indicated that sample containing soybean flour amount of 5% were better than other samples. The pH values and titratable acidities of stored protein-enriched fermented milk and fermented milk, respectively, were not remarkably different. Crude protein was more than 3 times higher in protein-enriched fermented milk (8.77%) than in fermented milk (2.49%). The crude fat content of protein-enriched fermented milk was not remarkably different compared to that of fermented milk. Dietary fiber was more than 2.7 times higher in protein-enriched fermented milk (1.67%) than in fermented milk (0.62%), and the free amino acid content was more than 14 times higher in protein-enriched fermented milk (37.9%) than in fermented milk (2.6%).

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.7-16
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• 2002

Contamination of groundwater by agrochemicals used in the regional-scale Is now a major environmental problem, and this is especially true for Cheju island where virtually all potable water is from groundwater. The objective of this study was to assess leaching potential of eight pesticides in soils of citrus orchards using groundwater ubiquity score (GUS), retardation factor (RF) and attenuation factor (AF). Considering GUS estimated in 30 citrus orchard soils, metribuzin and metolachlor were classified as leacher, alachlor in volcanic ash soils and linuron in non-volcanic soils were classified as leacher, but chlorothalonil and chlorpyrifos were classified as non-leacher. For RF values, metribuzin was classified to be mobile in soils of low organic carbon, metolachlor and alachlor were classified to be moderately immobile in most soils, but linuron, diuron, diniconazole, chlorothalonil and chlorpyrifos were all classified to be very immobile. For AF values, diniconazole, chlorothalonil, and chlorpyrifos were classified to be very unlikely leachable in all of the soils, metribuzin was classified to be likely leachable, and metolahclor, alachlor, linuron and diuron were classified to be leachable only in non-volcanic soils. Although there were some variations in the relative potential of teachability of pesticides estimated with the three different indices, the ranking was essentially determined on the base of the intrinsic properties of the chemicals and environmental properties. Among the eight pesticides, metribuzin, metolachlor, and alachlor, which have high water solubility and low $K_{oc}$ values, have a significant leaching potential especially in non-volcanic ash soils of low organic carbon. But diniconazole, chlorothalonil, and chlorpyrifos, which have low water solubility and high $K_{oc}$ values, were classified to be very immobile in all of the soils. Therefore, to lower the possibility of pesticide contamination of the groundwater in Cheju island, those pesticides which have high water solubility and low $K_{oc}$ values should be used with care in soils of low organic carbon including non-volcanic ash soils.

• Korean Journal of Environmental Agriculture
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• v.34 no.1
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• pp.38-45
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• 2015

BACKGROUND: For commercial production of greenhouse crops under shorter day length condition, supplementary radiation has been usually achieved by the artificial light source with higher electric consumption such as high-pressure sodium, metal halide, or incandescent lamps. Light-Emitting Diodes (LEDs) with several characteristics, however, have been considered as a novel light source for plant production. Effects of supplementary lighting provided by the artificial light sources on growth of Kale seedlings during shorter day length were discussed in this experiment. METHODS AND RESULTS: Kale seedlings were grown under greenhouse under the three wave lamps (3 W), sodium lamps (Na), and red LEDs (peak at 630 nm) during six months, and leaf growth was observed at intervals of about 30 days after light exposure for 6 hours per day at sunrise and sunset. Photosynthetic photon flux (PPF) of supplementary red LEDs on the plant canopy was maintained at 0.1 (RL), 0.6 (RM), and $1.2(RH){\mu}mol/m^2/s$ PPF. PPF in 3 W and Na treatments was measured at $12{\mu}mol/m^2/s$. Natural light (NL) was considered as a control. Leaf fresh weight of the seedlings was more than 100% increased under the 3 W, Na and RH treatment compared to natural light considering as a conventional condition. Sugar synthesis in Kale leaves was significantly promoted by the RM or RH treatment. Leaf yield per $3.3m^2$ exposed by red LEDs of $1.2{\mu}mol/m^2/s$ PPF was 9% and 16% greater than in 3W or Na with a higher PPF, respectively. CONCLUSION: Growth of the leafy Kale seedlings were significantly affected by the supplementary radiation provided by three wave lamp, sodium lamp, and red LEDs with different light intensities during the shorter day length under greenhouse conditions. From this study, it was suggested that the leaf growth and secondary metabolism of Kale seedlings can be controlled by supplementary radiation using red LEDs of $1.2{\mu}mol/m^2/s$ PPF as well as three wave or sodium lamps in the experiment.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.161-167
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• 2015

BACKGROUND: For the heavy metal cotamination sites, it is very important to estimate the human bioavailability quotients for heavy metals in paddy soils released from mine tailings, which is a major source of contamination in Korea, and to assess the human health risks of heavy metals. METHODS AND RESULTS: This experiment was carried out to investigate the human bioavailability quotient of the heavy metals in paddy soils below part of the closed metalliferous mine. For estimating the human bioavailability quotients for heavy metals, 30 paddy soils below part of the closed mine were collected, and analyzed for Cd, Cu, Pb, Zn, and As using simple bioavailability extraction test(SBET). The quantities of Cd, Cu, Pb, Zn and As extracted from paddy soils below part of the mine by using the SBET analysis were 28.1, 17.3, 34.1, 14.6 and 2.3% respectively. Specially, the maximum values of Cd, Pb and Zn were 73.3, 81.5 and 58.1% of human bioavailability quotient, respectively, and varied considerably among the sampling sites. The human bioavailability quotient of Cd, Cu, Pb and Zn in soils near the closed mine showed significant positive correlation among soil pH value, O.M. and Ex. Ca. contents, while it correlated negatively between soil Ex. K and Ex. Mg contents in paddy soils. Also, its of Cd, Cu, Pb and Zn in paddy soils showed significant positive correlation with 0.1M HCl extractable and total contents, while in soils, it correlated negatively with As content in soil near the closed mine. CONCLUSION: The results of the simple bioavailability extraction test (SBET) indicate that regular ingestion of soils by the local population could be closed a potential health threat due to long-term heavy metals exposure in these mine areas.