• 한국해양학회지
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• v.21 no.2
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• pp.110-117
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• 1986

In southeastern sea of Korea, ammonium excretion rates of mixed macrozooplankton population ranged from 0.90 to 2.32$\mu\textrm{g}$ atoms NH$\_$4/-Nm$\^$-3/h$\^$-1/ and zooplankton excretion contributed from 3 to 15% of total nitrogen requirement by phytoplankton. Wet weight specific ex cretion rate was averaged to be 3.45$\mu\textrm{g}$ atoms NH$\_$4/-Ng$\^$-1/wet weight h$\^$-1/. Zooplankton biomass in wet weight and protein tended to increase to ward outer outer shelf. GDH assay of macrozooplankton demonstrated a typical Michaelis-Mentenkinetics with 5.1mM of half saturation constant(Km). Protein specific GDH activity in the present study ranged from 1.5 to 3.2$\mu\textrm{g}$ atoms NH $\_$4/-N mg$\^$-1/protein h$\^$-1/. Higher protein specific GDH activity in the outer shelf implies that zooplankters in the outer shelf were more active in nitrogen metabolism grazing higher primary production in the outer shelf. In the present study, averaged GDH/excretion ratio was 18.8${\pm}$2.6(n=6)showing high correlation between zooplankton GDH activity and direct ammonium excretion rate by zooplankton. GDH assay can be extremely useful in the future study for the ammonium regeneration by different size zooplankton fraction in various marine environments.

• Journal of Soil and Groundwater Environment
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• v.15 no.3
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• pp.61-68
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• 2010

Phytoextraction, one type of phytoremediation processes, has been widely used in the removal of heavy metals from polluted soil. This paper reviewed literature on metal uptake by plants and characterized the metal uptake by types of metals (Zn, Cu, Pb, Cd, and As), plant species, initial metal concentrations in soil and the distribution of metals in different parts of plants. The potential of metal accumulation and transport by plants was closely related to plants species, types of metals, and initial metal concentrations in soil. The plants belonging to Brassicaceae, Solanaceae, Poaceae, and Convolvulaceae families have shown the high potential capacity of Cd accumulation. The Gentianaceae, Euphorbiaceae, and Polygonaceae families have exhibited relatively high Pb uptake potential while the Pteridaceae and Cyperaceae families have shown relatively high Zn uptake potential. The Pteridaceae family could uptake a remarkably high amount of As compared with other plant families. The potential metal accumulation per plant biomass has increased with increasing initial metal concentration in soil up to a certain level and then decreased for Cd and Zn. For As, only Pteris vittata had a linear relationship between initial concentration in soil and potential of metal uptake. However, a meaningful relationship for Pb was not found in this study. Generally, the plants having high metal uptake potential for Cd or Pb mainly accumulated the metal in their roots. However, the Euphorbiaceae family has accumulated more than 80% of Pb in shoot. Zn has evenly accumulated in roots and stems except for the plants belonging to the Polygonaceae and Rosaceae families which accumulated Zn in their leaves. The Pteridaceae family has accumulated a higher amount of As in leaves than roots. The types of metals, plant species, and initial metal concentration in soil influence the metal uptake by plants. It is important to select site-specific plant species for effective removal of metals in soil. Therefore, this study may provide useful and beneficial information on metal accumulation by plants for the in situ phytoremediation.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.45-51
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• 2014

This is to study the effects of various pretreatment methods of agricultural residue, corn stover, and to compare the feature and pros and cons of each method including dilute sulfuric acid (DSA), soaking in aqueous ammonia (SAA), and ammonia recycle percolation (ARP). In order to convert corn stover to ethanol, various pretreatments followed by simultaneous saccharification and co-fermentation (SSCF) were tested and evaluated in terms of ethanol yield. With 3%, w/w of glucan loading using ARP-, DSA-, and SAA-treated solids, SSCFs using recombinant E. coli strain (ATCC$^{(R)}$ 55124) with commercial enzymes (15 FPU of Spezyme CP/g-glucan and 30 CBU/g-glucan enzyme loading) were tested. In the SSCF tests, 87, 90, and 78% of theoretical maximum ethanol yield were observed using ARP-, DSA-, and SAA-treated solids, respectively, which were 69, 58, and 74% on the basis of total carbohydrates (glucan + xylan) in the untreated corn stover. Ethanol yield of SAA-treated solid was higher than those of ARP- and DSA-treated solids. In addition, SSCF test using treated solids plus pretreated hydrolysate indicated that the DSA-treated hydrolysate showed the strongest inhibition effect on the KO11 strain, whereas the ARP-treated hydrolysate was found to have the second strongest inhibition effect. Bioconversion scheme using SAA pretreatment and SSCF can make the downstream process simple, which is suggested to produce ethanol economically because utilization of hemicellulose in the hydrolysate is not necessary.

• The Korean Journal of Malacology
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• v.28 no.2
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• pp.91-99
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• 2012

Corbicula japonica, belonging to Other Veneroida Family Corbiculidae, was distributed in the freshwater and brackish rivers, where was a sandy and shallow depth. Catch of C. japonica in the Seomjin River occupied at a large portion of the catch in Kyungnam Province, which was about 30% of total catch in Korea. C. japonica has little studied on biomass, scientific resources assessment and management, because of inaccurate catch report data in the Seojin River. In this study, we conducted scientific and systematic approaches under data limited situation with application of the potential fishery yield system for sustainable fisheries resources management. Estimation system of the potential fishery yield was consisted of 5 tier system. We have used to tier 1 and 2 which were demanded higher level of information than the other tiers. The potential fishery yields were estimated 77.66ton for tier 1 using commercial fishery-dependent data, and 129.82ton for tier 2 with fishery-independent survey data.

• Korean Journal of Agricultural Science
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• v.45 no.2
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• pp.197-203
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• 2018

Biochar is the carbon solid produced through the pyrolysis of a biomass from organic sources such as agricultural waste, animal manure, and sludge under limited or anaerobic conditions. Biochar has the effect of reducing greenhouse gases through the carbon sequestration method; additionally, biochar is known to function as a soil amendment. This experiment was conducted to evaluate the application of biochar on the growth characteristics of Chinese cabbage at Chungnam National University in Daejeon, Korea. The Chinese cabbage was grown for 50 days in a glasshouse in pots. A pruning branch was used to produce the bead and pellet forms of biochar through pyrolysis. The biochar was added to the soil at 0, 2, and 5% by weight. The Chinese cabbage with the 2% treatment of the bead form of biochar had the highest fresh weight ($149.43{\pm}15.92g\;plant^{-1}$) which was increased by 10% compared to the control ($136.91{\pm}31.46g\;plant^{-1}$). Moreover, for the 5% treatment of the bead form of biochar ($60.91{\pm}9.82g\;plant^{-1}$), the growth decreased by 57% compared to the control. As the content of the bead form of biochar increased, the shoot dry weight, leaf number, leaf length and lead width that appeared decreased. An increase in the total organic matter, Avail. $P_2O_5$, Ex. cation and EC was observed when the biochar content was increased. Our results support the application of 2% biochar in the bead form for increased growth of Chinese cabbage.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.155-164
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• 2010

Emission from biomass combustion such as meat charbroiling is an important source of organic aerosol. Since source profiles are necessary input profiles for source apportionment of aerosol by a chemical mass balance model, meat cooking organic source profiles are developed by measuring organic marker compounds, including palmitic acid, stearic acid, oleic acid and cholesterol as well as PAH compounds. Emissions from meat and pork charbroiling are collected on quartz filters with a PM10-high volume sampler, extracted with organic solvents, derivatized with diazomethane/TMS and analyzed by GC/MS isotope dilution method. Organic and elemental carbon are also analyzed by an OCEC analyzer. Wt.% of cholesterol to the organic carbon(OC) content from beef and pork charbroiling is only 0.056 and 0.062, but wt. % of all saturated fatty acids to the OC content from beef and pork charbroiling is 2.727 and 2.022, and the wt% of all unsaturated fatty acids to the OC content is 0.278 and 0.438, respectively. Content of total PAH compounds to the OC content from beef charbroiling is higher than that from pork charbroiling, and those are 0.116 wt% and 0.044 wt%. Among PAH compounds benzo(a)pyrene as a single compound is account for 0.0071 wt% and 0.0023 wt% of OC content from beef and pork charbroiling. Ratios of marker compound to cholesterol are calculated, and those values are in good agreement with the values already reported at the food cooking emission, indicating that they can be used as organic source profiles for the apportionment of organic aerosol.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.331-336
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• 2010

This study was carried out to investigate the dose-dependent effect of methyl jasmonate on both the adventitious root growth and the accumulation of various eleutherosides in the bioreactor culture of Eleutherococcus senticosus adventitious roots. The highest biomass production (5.4 g DW/L) was observed in the absence of methyl jasmonate and the root growth was significantly decreased by increasing the methyl jasmonate concentration. However, methyl jasmonate stimulated the production of both eleutheroside B, E and $E_1$. The highest level of eleutheroside B (359.9 ${\mu}g$/g DW) was obtained at 40 ${\mu}M$ of methyl jasmonate, while eleutheroside E and $E_1$ was accumulated at the highest level by the addition of 10 ${\mu}M$ of methyl jasmonate. Total eleutheroside was increased up to 3818.1 ${\mu}g$ per liter when 10 ${\mu}M$ of methyl jasmonate was applied. In addition, when the adventitious roots were cultured with 20 ${\mu}M$ of methyl jasmonate, the highest levels of eleutheroside B, E and $E_1$ were observed at the 12th, 3th and 9th days of culture, respectively.

• Journal of Environmental Science International
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• v.10 no.2
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• pp.119-127
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• 2001

The Keum river is one of the important river in Korea and has a drainage area of 9,873$\textrm{km}^2$. The Keum river is deepening pollution state due to development of the lower city and construction of a industrial complex. The water quality of the Keum river come to eutrophication state and belong to III grade of water quality standard. The concentration BOD in river is affected by the organic loading from a tributary and the algae biomass that largely happen to under eutrophication state. In the eutrophic water mass such as the Keum river, the autochthonous BOD was very important part for making a decision of water quality management, because it was accounted for majority of the total BOD. The purpose of this study was to survey the chatacteristics of water quality in summer and to estimate reaction coefficient. Also, we studied to correlationship between chlorophyll a and BOD(COD) for estimation of the autochthonous BOD. The correlationship between chlorophyll a and BOD(COD) were obtained through the culture experiment of phytoplankton in the laboratory. The results of this study may be summarized as follows ; The characteristics of water quality in summer were belong to III~IV grade of water quality standard as BOD and nutritive condition is very high. The BOD, ammonia nitrogen and phosphate loadings in Miho stream which inflowing untreated sewage from Chungju city was occupied with 64.07%, 26.36%, 46.08%, respectively. Maximum nutrient uptake (Vmax) was 0.4400$\mu$M/hr as substrate of ammonia nitrogen, 0.1652$\mu$M/hr as substrate of phosphate. Maximum specific growth rate ($\mu$max) was 1.2525$hr^{-1}$ as substrate of ammonia nitrogen, 1.5177$hr^{-1}$ as substrate of phosphate. The correlation coefficient between chlorophyll a and BOD by the culture experiment were found to be 0.911~0.935 and 0.942~0.947 in the case adding nutrient and no adding nutrient, respectively. The correlation coefficient between chlorophyll a and COD through the culture experiment were found to be 0.918~0.977 and 0.880~0.931 in the case adding nutrient and no adding nutrient, respectively. The autochthonous BOD(COD) was estimated to the relationship between BOD(COD) and chlorophyll a. The regression equation were found to be autochthonous BOD=(0.045~0.073)${\times}chlorophyll$ a and autochthonous $COD=(0.137~0.182){\times}chlorophyll$ a.

• Journal of the Korean earth science society
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• v.24 no.3
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• pp.216-233
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• 2003

This study delineates the phenomena related with global environmental changes such as global warming, ozone depletion, and El Ni${\tilde{n}}$o/Southern Oscillation (ENSO) noted in the Antarctic. Retreat of ice cliffs, glaciers, and calving of ice shelves indicate the effects of recently aggravated global warming. The ice cliff located at Marian Cove, King George Island, South Shetland Islands off the Antarctic Peninsula has been observed to be retreating faster in the last 7 years than in the previous 38 years since 1956. There are some indications of temperature and precipitation changes associated with ENSO around King Sejong Station. The regression analyses indicate significant trends such as a decrease in the total amount of ozone and an increase in ultraviolet radiation which was seen by a satellite (TOMS-EUV) in September and October which correspond to ozone-hole season over King Sejong Station. Increase of UV radiation due to the ozone depletion in the Antarctic has changed the growth rate of marine organisms. It may also result in changes to the productivity, biomass, and species composition of marine organisms which can affect the whole marine ecosystem. The recent ice-core drilling over Lake Vostok has been reviewed with emphasis on the four cycles of glacial stages over the past 420,000 years. It is time to show more interest in mainland Antarctica through investigations of the coring and vast ice sheet, terrestrial geology, and upper atmospheric sciences in order to understand the past environmental changes and to predict possible changes to the environment in the future.

• Korean Journal of Environment and Ecology
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• v.12 no.1
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• pp.30-41
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• 1998

This study analyzed urban greenspace area and vegetation structure by land use types for Kangnam-gu and Junglang-gu in Seoul different in income and building construction date. The study districts had a similar areal distribution of land use types. Residential lands accounted for about 32~37% of total area, natural lands, 19~22%, commercial and industrial lands(including transportation), 13~18%, and institutional lands, 13~17%. Greenspace covered only 20~30% of urban residential and commercial area in which human activities of living concentrate. Canopy stocking level in urban lands (all land uses except natural and agrecultural lands) was about 39% for Kangnam-gu and 50% for Junglang-gu, showing tree planting potential slightly higher in Kangnam-gu than in Junglang-gu. Woody plant cover was approximately 13%, and tree density was 3 trees/100m$^{2}$ forurban lands in both districts. The tree-age structure was largely characterized by young, growing tree population, and species diversity within a diameter class decreases as the diameter classes get larger. Urban lands of both districts had quite a similar species composition of woody plants (similarity indez of 0.70). Income and bulding construction date did not result in significant diference between the two districts in vegetation structure for urban lands. Some strategies were ezplored to solve problems found in the present greenspace structures. They included increase of biomass and greenspace area through minimization of unnecessary impervious surfaces, creation of multilayered and multiaged vegetation structures, and avoidance of intensive tree pruning and relocation of above ground utility lines.