• Journal of Environmental Science International
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• v.26 no.6
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• pp.691-710
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• 2017

This study was performed to investigate the geochemical and benthic environment of three shellfish farms in Suncheon Bay during the period of September 2014 ~ April 2015. Three sampling stations were selected; St.1 is the shellfish farm of razor clam near Jangsan area. St.2 is the shellfish farm of small ark shell near Hwapo area and St.3 is the shellfish farm of razor clam near Yongdu area. Razor clam was the dominant species at St.1, small ark shell and granulated ark shell were dominant at St.2 and St.3, respectively. Granulated ark shell inhabited St.3, although it is not cultured at that station. This station's exposure to air during the ebb tide and sediment composition likely provides the appropriate habitat for granulated ark shell species. Analysis of the number of different species showed that 8 benthos species were found to be distributed at St.1, 18 species at St.2, and 13 species at St.3. Among three stations, the highest Ignition Loss (IL), Chemical Oxygen Demand (COD) and Acid Volatile Sulfide (AVS) values were obtained from the sediment at St.2. The analysis of pore water from St.2 also showed the highest values of Total Organic Carbon (TOC), ammonia ($NH_4^+$), Dissolved Inorganic Nitrogen (DIN) and phosphate ($PO_4^{3-}$). These results are related to the fact that species dominance and richness is the highest in St.2.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.211-222
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• 2013

Objectives: A great number of people visit forests for their bountiful healing factors. We investigated the quantity of terpene and analyzed the correlations with meteorological and environmental factors at Mt. Mudeung in order to support public health. Methods: The terpene amounts were investigated along 11 main trails using stainless steel tube packed by Tenax TA (150 mg) and Carbopack B (130 mg) during March to November 2012. Terpene amounts of 20 species (${\alpha}$-pinene, camphene, etc.), and meteorological and environmental factors were investigated in the field. Results: Terpene of 16 species was released from the forest and total terpene amounts were 2,080 pptv at the site of Chamaecyparis obtusa, the highest among 11 sites, nearby the first reservoir on Mt. Mudeung. Terpene concentrations in the forest were nine to 23 times higher than found in urban areas. Total terpene amounts had positive correlations with temperature, humidity, carbon dioxide and oxygen (p<0.01) with $R^2$ of 0.345, 0.369, 0.591, 0.145, respectively, from April to July. Wind speed and solar radiation in the forest had a negative correlation with terpene amounts and showed statistical insignificance with p-values of 0.118 and 0.233, respectively. Conclusions: This study suggests that the amounts of terpene around Mt. Mudeung are indeed higher, so visitors may enjoy a therapeutic walk in the forest with a healing effect. These results showed the forest was very effective for improving human health.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.219-225
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• 1978

Several samples of tile dried purple laver grown and processed at the major laver producing districts, i. e Mokpo, Wando, Hadong and Jangrim, along the southern coast of Korea were Quantitatively investigated to determine composing patterns of the fatty acids by gas-liquid chromatography. The total lipid contents in dried purple laver of Hadong were $1.8\%$ being the highest value. Upon analyzing fatty acid composition, some differences were observed in their quantitative distribution at different growing places. Dried purple laver of Wando contained mainly $C_{16:0},\;C_{18:1},\;C_{16:1}\;and\;C_{17:0}$ fatty acids, that of Mokpo contained $C_{16:0},\;C_{20:5},\;C_{18:1}\;and\;C_{16:1}$ fatty acids, and that of Hadong $C_{16:0},\;C_{20:5},\;C_{18:0}\;and\;C_{20:1}$ fatty acids, and that of Jangrim $C_{20:5},\;C_{16:0},\;C_{18:1}\;and\;C_{18:0}$ fatty acids, each in order of acid quantity. In regard to the composing pattern of carbon number of fatty acids, the dried purple laver o Mokpo, Hadong, and Jangrim contained $C_{16},\;C_{18}\;and\;C_{20}$ fatty acids with the identical distributional pattern, while that of Jangrim contained $C_{16},\;C_{18}\;and\;C_{17}$ fatty acids as major components. Dried Purple laver of Jangrim contained especially high amount of $C_{20:5}$ fatty acids.

• Journal of the Korean Applied Science and Technology
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• v.14 no.1
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• pp.61-76
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• 1997

Triacylglycerols of the seeds of Ginkgo biloba have been resolved by high-performace liquid chromatography(HPLC} in the silver-ion and reverse-phase modes. The fatty acids were identified by a combination of capillary gas chromatography and gas-chromatography /mass spectrometry as the methyl and /or picolinyl ester. The main components are $C_{18:2{\omega}6}$(39.0mol%), $C_{18:1{\omega}7}$(asclepic acid 21.5mol%), and $C_{18:1{\omega}9}$(oleic acid, 13.8mol%). Considerable amounts of unusual acid such as $C_{20:3{\Delta}^{5,11,14}$ (5.7mol%), $C_{18:2{\Delta}^{5,9}$(2.8mol%), and $C_{18:3}{\Delta}^{5,9,12}$(1.6mol%), were checked. In addition, an anteiso-branched fatty acid, 14-methylhexadecanoic acid, was also present as a minor component(0.9 mol%). The triacylglycerols were separated into 17 fractions by reverse-phase HPLC, and the fractionation was achieved according to the partition numnber(PN) in which a ${\Delta}^5$-non methylene interrupted double bond($^5$-NMDB) showed different behaviour from a methylene interrupted double bond in a molecule with a given cahinlength. Silver-ion HPLC exhibited excellent resolution in which fractions(23 fractions) were resolved on the basis of the number and configuration of double bonds. In this instance, the strength of interaction of a ${\Delta}^5$-NMDB system with silver ions seemed to be weaker than a methylene interrupted double bond system. The principal triacylglycerol species are as follows ; $(C_{18:2{\omega}6)2}/C_{18:1{\omega}7}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$, $C_{16:1{\omega}7}/C_{18:1{\omega}9}/C_{20:3}{\Delta}^{5,11,14}$, $C_{16:1{\omega}7}/C_{18:1{\omega}7}/C_{20:3}{\Delta}^{5,11,14}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $C_{18:1{\omega}9}/C_{18:2}{\Delta}^{5,5}/C_{20:3}{\Delta}^{5,11,14}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$ and $(C_{18:1{\omega}9)2}/C_{18:2{\omega}6}$, while simple triacylglycerols without $C_{18:2{\omega}6})_3$ were not present. Stereospecific analysis showed that fatty acids with ${\Delta}^5$-NMDB system and saturated chains were predominantly located at the site of sn-3 carbon of glycerol backbones. It is evident that there is asymmetry in the distribution of fatty acids in the TG molecules of Ginkgo nut oils.

• 한국해양학회지
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• v.3 no.1
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• pp.16-25
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• 1968

This study was undertaken to assess the annual cycle of primary production and plant pigments in a downstream of the Han River. Measurements were carried out at three week intervals during April 1966 and March 1967, and ancillary data include water temperature, transparency, pH, dissolved oxygen and phytoplankton cell number. The seasonal cycle in water temperature profile shows the hihgest in the end of August with 27$^{\circ}C$, lowest in the middle of February with 0.2$^{\circ}C$. The transparency with Secchi disk reading varied from a maximum 4.0m in fall and a minimum 0.5m or less in early spring and flood season of summer. The pH of the river water varied from 6.5 to 7.3, averaged 6.91 in the surface water and 6.98 in the bottom water, showed little seasonalvariability. The dissolved oxygen in the surface water ranged from 5.93-9.64ml/L, while in the bottom water it ranged from 5.54-9.72 ml/L, and the oxygen saturation never fall below 94%. None thermal, the distribution of pH and content of oxygen, stratifications occurred. An apparent seasonal cycle of primary productivity was observed with remarkably high levels in the spring and fall, the lowest level in the winter. The range of net carbon assimilations showed 3.1-112.6 mgC/㎥/day or 15-427 mgC/㎡/day in spring, 37.0-271.2 mgC/㎥/day or 115-329 mgC/㎡/day in summer, 27.2-168.0 mgC/㎥ /day or 139-415 mgC/㎡/day in fall and 0.5-10.9 mgC/㎥/day or 5-19 mg/㎡/day in winter, respectively. Amount of chlorophyll ${\alpha}$ ranged from a minimum concentration of 0.2-0.3 mg/㎥ in the middle of February and a maximum 4.1-6.7 mg/㎥ in the middle of June. A general increase trend in chlorophyll ${\alpha}$ concentration was noted with increase of the river water temperature.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.568-573
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• 2008

Kinetic tests on pyrolysis of waste fishing net [WFN; nylon-6], waste ship lubricating oil [WSLO] and their mixture were carried out by thermogravimetric analysis (TGA) with heating rate of 0.5, 1.0, and $2.0^{\circ}C/min$. Pyrolysis of waste fishing net started at $300^{\circ}C$, and the main region of decomposition temperature was between 360 and $440^{\circ}C$ at each heating rate. Decomposition temperature of the mixture of WFN and WSLO was lower than that of WFN and WSLO, and the shape of thermogravimetic graph of mixture was different as well. The corresponding kinetic parameters including activation energy and pre-exponential factor were determined by differential method over the degree of conversions. The values of activation energies for the mixture of WFN and WSLO were between 98 and 427 kJ/mol as the conversion increased from 5% to 95%. Tubing reactor was used to analysis of pyrolyzed oil at $440^{\circ}C$ for 80 min. The selectivity of specific hydrocarbons was not detected and the carbon number distribution of the pyrolyzed oil was below $C_{22}$.

• Korean Journal of Environmental Biology
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• v.17 no.2
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• pp.129-138
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• 1999

Chlorinated aromatic compounds are one of the largest groups of environmental pollutants as a result of world-wide distribution by using them as herbicides, insecticides, fungicides, solvents, hydraulic and heat transfer fluids, plasticizers, and intermediates for chemical synthesis. Because of their toxicity, persistence, and bioaccumulation, the compounds contaminated ubiquitously in the biosphere has attracted public concerns in terms of serious influences to wild lives and a human being, such as carcinogenicity, mutagenicity, and disturbance in endocrine systems. The biological recalcitrance of the compounds is caused by the number, type, and position of the chlorine substituents as well as by their aromatic structures. In general, the carbon-halogen bonds increase the recalcitrance by increasing electronegativity of the substituent, so that the dechlorination of the compounds is focused as an important mechanism for biodegradation of chlorinated aromatics, along with the cleavage of aromatic rings. The removal of the chlorine substituents has been known as a key step for degradation of chlorinated aromatic compounds under aerobic condition. This can occur as an initial step via oxygenolytic, reductive, and hydrolytic mechanisms. The studies on the biochemistry and genetics about microbial dechlorination give us the potential informations for microbial degradation of xenobiotics contaminated in natural microcosms. Such investigations might provide biotechnological approaches to solve the environmental contamination, such as designing effective bioremediation systems using genetically engineered microorganisms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.979-984
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• 2011

Although sludge production has been increased due to the number of the wastewater treatment plants expanded, needs of the techniques for the sludge reduction and disposal has been issued importantly because the sludge dumping to ocean is prohibited from 2012 by the London Dumping Convention. Therefore, the sludge solubilization using electrolysis as an alternative techniques for the sludge disposal was carried out in this study. Iridium coated titanium based insoluble electrodes were used and 20 volt was applied to the electrolysis reactor using DC power supply. Supernatants of the treated sludge was monitored: The soluble COD, TN, TP of it was increased to 151%, 22% and 6% respectively. And the sludge floc size distribution was changed, that is, the flocs ranged from 0.1 to 1.0 ${\mu}m$ were increased. All of these results indicate that the cells were lysed and the internal matters bursted out of the cell after electrolysis. As well as the reduction of the sludge production, the soluble organic matters from the cells could be used as an external carbon sources in the advanced wastewater treatment plants.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.253-258
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• 2018

Phytoplankton community was studied in relation to a typhoon at Bok-gyo Bridge area in Juam Lake, Korea. In August 31, 2000, a typhoon (Prapiroon) was passed by Juam Lake with great power enough to destroy summer stratification of Juam Lake. Destratification resulted in temporal mixing of the whole water column and changed the physical and chemical properties of water bodies, and caused the changes of the biological properties. The transparency decreased from 195 cm before the typhoon to 84 cm after the typhoon with the resuspension of the bottom sediment. In the vertical distribution of the phytoplankton population, the maximum population was measured at depth of 2 m before the typhoon. However, immediately after the typhoon, the population distributed evenly throughout the entire water layers. The carbon biomass of the phytoplankton was also highest at the depth of 2 m before the typhoon, but immediately after the typhoon, it was uniformly distributed throughout the whole water layers. The vertical profiles of the concentrations of chlorophyll a, however, did not show a significant difference before and after the typhoon. The typhoon induced destratification and restratification altered the taxa of the phytoplankton. The major dominant phytoplankton taxa before the typhoon was diatoms including Aulacoseira granulata, but the green algae overwhelmed the diatoms in cell number and biomass after the typhoon. The chlorophycean dominance was replaced by cyanophycean dominance with the heavy rain and descent of water temperture at the end of September.

• Clean Technology
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• v.29 no.4
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• pp.272-278
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• 2023

There is a lot of interest in methods for pollutants using adsorption, and recent research is being conducted to show that biochar can be used to remove organic and inorganic pollutants. In particular, wood waste as waste biomass requires a biomass recycling method, and a method to increase the adsorption capacity of biochar produced using wood waste is needed. Biochar is created by Hydrothermal carbonization (HTC) using, which uses low temperature and high pressure, has low energy consumption and does not require moisture removal pretreatment, and biochar is created through chemical activation using KOH, NaOH, and ZnCl₂ chemicals. The adsorption characteristics of biochar were determined by analyzing iodine adsorptivity, specific surface area, pore diameter, pore volume, pore distribution, and SEM according to the activation. The results of analyzing the selecting biochar by activating the biochar produced at HTC 300℃, 4 hr by KOH, NaOH, and ZnCl₂ chemicals, the specific surface area was 774~1.387 m²/g, showing a high specific surface area similar to activated carbon, and it was confirmed that micropores with an average pore diameter in the range of 21~24 Å were formed. As a result of SEM observation, the surface was uniform with a certain shape depending on activation. It was confirmed that one pore was developed and the number of pores increased.