• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.55-65
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• 2003

The combined effect of bioaugmentation of dechlorinating bacterial cultures and addition of iron powder($Fe^0$ on reductive dechlorination of tetrachloroethylene(PCE) and other chlorinated ethylenes in a artificially contaminated soil slurry(60micromoles PCE/kg soil). Two different anaerobic bacterial cultures, a pure bacterial culture of Desulfitobacterium sp. strain Y-51 capable of dechlorinating PCE to cis-1,2-dechloroethylene(cis-DCE) and the other enrichment culture PE-1 capable of dechlorinating PCE completely to ethylene, were used for the bioaugmentation test. Both treatments introduced with the strain Y-51 and PE-1 culture (3mg dry cell weight/kg soil) showed conversion of PCE to cis-DCE within 40days. The treatments added with $Fe^0$(0.1-1.0%) alone to the soil slurry resulted in extended PCE dechlorination to ethylene and ethane and the dechlorination rate depended on the amount of $Fe^0$ added. The combined use of the bacterial cultures with $Fe^0$(0.1-1.0%)) showed the higher PCE dechlorination rate than the separated application and the pattern of PCE dechlorination and end-product formation was different from those of the separated application. When 0.1% of $Fe^0$ was added with the cultures, the treatments with the strain Y-51 and $Fe^0$ resulted in cis-DCE accumulation from PCE dechlorination, but the treatment with the enrichment culture and $Fe^0$ showed the more extended dechlorination via cis-DCE. These results suggested that the combined application of and the bactrial culture, specially the complete dechlorinating enrichment culture, is practically effective for bioremediation of PCE contaminated soil.

• Economic and Environmental Geology
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• v.30 no.5
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• pp.417-431
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• 1997

Characteristics of sedimentary rocks and enrichment of toxic elements in shale and coal from the Chungnam coal field were investigated based upon geochemistry of major, trace and rare earth elements. Shale and coal of the area are interbedded along the Traissic to the Jurassic Daedong Supergroup, which can be subdivided into grey shale, black shale and coal. The coal had been mined, however all the mines are abandonded due to the economic problems. The shale and coal are characterized by relatively low contents of $SiO_2$, and $Al_2O_3$ and high levels of loss-on-ignition (LOI), CaO and $Na_2O$ in comparison with the North American Shale Composite (NASC). Light rare earth elements (La, Ce, Yb and Lu) are highly enriched with the coal. Ratios of $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ in shale and coal range from 30.0 to 351.8 and from 4.2 to 106.8, which have partly negative correlations against $SiO_2/Al_2O_3$ (1.24 to 6.06), respectively. Those are suggested that controls of mineral compositions in shale and coal can be due to substitution and migration of those elements by diagenesis and metamorphism. Shale and coal of the area may be deposited in terrestrial basin deduced from high C/S (39 to 895) and variable composition of organic carbon (0.39 to 18.40 wt.%) and low contents of reduced sulfur (0.01 to 0.05 wt.%). These shale and coal were originated from the high grade metamorphic and/or igneous rocks, and the rare earth elements of those rocks are slightly influenced with diagenesis and metamorphism on the basis of $Al_2O_3$ versus La, La against Ce, Zr versus Yb, the ratios of La/Ce (0.38 to 0.85) and Th/U (3.6 to 14.6). Characteristics of trace and rare earth elements as Co/Th (0.07 to 0.86), La/Sc (0.31 to 11.05), Se/Th (0.28 to 1.06), V/Ni (1.14 to 3.97), Cr/V (1.4 to 28.3), Ni/Co (2.12 to 8.00) and Zr/Hf (22.6~45.1) in the shale and coal argue for inefficient mixing of the simple source lithologies during sedimentation. These rocks also show much variation in $La_N/Yb_N$ (1.36 to 21.68), Th/Yb (3.5 to 20.0) and La/Th (0.31 to 7.89), and their origin is explained by derivation from a mixture of mainly acidic igneous and metamorphic rocks. Average concentrations in the shale and coal are As=7.2 and 7.5, Ba=913 and 974, Cr=500 and 145, Cu=20 and 26, Ni=38 and 35, Pb=30 and 36, and Zn=77 and 92 ppm, respectively, which are similar to those in the NASC. Average enrichment indices for major elements in the shale (0.79) and coal (0.77) are lower than those in the NASC. In addition, average enrichment index for rare earth elements in coal (2.39) is enriched rather than the shale (1.55). On the basis of the NASC, concentrations of minor and/or environmental toxic elements in the shale and coal were depleted of all the elements examined, excepting Cr, Pb, Rb and Th. Average enrichment indices of trace and/or potentially toxic elements (As, Cr, Cu, Ni, Pb, U and Zn) are 1.23 to 1.24 for shale and 1.06 to 1.22 for coal, respectively.

• Korean Journal of Organic Agriculture
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• v.15 no.1
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• pp.71-84
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• 2007

Predicting plant responses to changing atmospheric $CO_2$ and to the possibility of global warming are important concerns. The $CO_2$ concentration of the global atmosphere has increased during the last decades. This increase is expected to result in changes of global temperatures and this will also affect the growth and development of bell pepper (Capsicum annum L.) and other crops. The objective of this study was to evaluate the effects of atmospheric $CO_2$ enrichment and high temperature on the growth and development of bell pepper under three temperature regimes. There was no statistical difference in the days required from seeding to flowering between $CO_2$ treatments, whereas among three temperature regimes, high temperature plots of $35/25^{\circ}C$ showed the shortest days (52.5 days) required from seeding to flowering. The plant height of bell peppers 15 weeks after emergence showed no statistical significance, while plots of $30/20^{\circ}C$ showed the highest plant height among the three temperature regimes. Time-course response of plant height to $CO_2$, enrichment was restrained in high $CO_2$, concentration (800ppm), at the same time higher temperature promoted plant height. Average leaf area per plant of 400ppm was $6,008.8cm^2$ and it was $5,225.1cm^2$ in the plots of 800ppm, showing 15% more leaf area compared to 400ppm $CO_2$ concentration. Leaf dry weight between $CO_2$ concentration and among temperature regimes showed a statistical significance. The average leaf dry weight in the plot of 800ppm showed the highest (44.1g), which was 18.5% higher compared to that of 400ppm (37.2g) and among temperature regimes, it was the highest (49.8g) in the plot of $35/25^{\circ}C$. Above-ground dry weight showed statistical significance between $CO_2$ concentration and among temperature regimes. The average above-ground dry weight of 800ppm $CO_2$ concentration was 141.4g, 17.9% higher compared to 400ppm $CO_2$ concentration (119.9g). Among three temperature regimes, plots of $30/20^{\circ}C$ showed the highest average above-ground dry weight (168.9g), while plots of $35/25^{\circ}C$ were the lowest (102.3g). In the average bell pepper dry weight, 800ppm of $CO_2$ concentration showed higher bell pepper dry weight (59.5g) than that (44.3g) of 400ppm of $CO_2$ concentration. It was judged that high $CO_2$ concentration was profitable fur bell pepper yield and there was a tendency that when there was high $CO_2$, concentration (800ppm), low temperature ($25/15^{\circ}C$) was profitable for bell pepper dry weight, whereas it was the reverse ($30/20^{\circ}C$), in the case of ambient $CO_2$, concentration (400ppm). In the specific leaf area according to $CO_2$, concentration, 800ppm showed 117.4, which was 35.5% higher compared to that (159.1) of 400ppm, showing that leaf becomes thicker as $CO_2$ concentration increases. Regarding correlation coefficients among crop characteristics, leaf area was negatively correlated with the number of bell peppers per plant and bell pepper dry weight, showing that the higher the leaf area, the lower the bell pepper yield. Bell pepper dry weight per plant showed positively significant correlation with the number of bell peppers per plant and total above dry weight, which showed that the higher the number of bell peppers and the total above dry weight, the higher the bell pepper yield.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.4
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• pp.213-228
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• 2009

This study was conducted to investigate spatio-temporal changes in macrobenthic community structure and benthic environmental conditions in Geoje-Hansa Bay, which is the greatest oyster producing site in Korea. Field survey for benthic environment and macrobenthos was seasonally carried out at 15 stations covering oyster farming sites and non-farming sites from February to November, 2008. The grain size of surface sediments was dominated by very fine silt with the mean phi of about $9\;{\Phi}$ and TOC was 1.9% on average. Mean dissolved oxygen content was 8.1 mg/L and lowest in August corresponding to the 2nd degree in seawater quality criteria. Total species number was 351 and mean density was $3,675\;ind./m^2$, both of which were dominated by polychaete worms. Spatio-temporal variation in above two biological variables was great with higher values seasonally in spring and spatially in channels rather than inner bay. Dominant species were Lumbrineris longifolia (21.3%), Aphelochaeta monilaris (17.8%) and Ericthonius pugnax(6.1%), all of which are typical species of organically enriched area. From the multivariate analyses, the whole macrobenthic community was distinguished into two groups of channel and inner bay group. Spatio-temporal changes of macrobenthic community in Geoje-Hansan Bay were related to those of TOC and acid volatile sulfide (AVS). Our results showed that Geoje-Hansan Bay should be intermediately affected by organic pollution, and that such organic enrichment was more remarkable at farming stations in the inner bay.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.159-169
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• 2007

Excessive input of organic matters from fish cage farms to the coastal waters has been considered as one of the major factors disturbing their benthic ecosystem. Sediment samples were taken from around the two fish cage zones (A and B) in Tongyeong coast in June and August 2003, to evaluate the ecological impacts of fish cage farming activity on the macrobenthic polychaete communities. Polychaete accounted for $81{\sim}87%$ of the total macrofauna individuals from each of the sampling stations. The number of species, abundance, diversity and dominant species of polychaete were rapidly changed with the distance from the fish cages. Within 10 m from the fish cages, Capitella capitata, which is a bio-indicator for the highly enriched sediments, was a dominant species and the lowest diversity was recorded. In particular, the maximum density (${\sim}18,410\;ind.m^2$) of C. capitata was found at Farm A where fish cages were more densely established within a semi-enclosed bay system. The sampling zone between 10 m and 15 m showed a rapid decrease of C. capitata with a rapid increase of the numbers of species, implying that this zone may be an ecotone point from a highly to a slightly enriched area. In the sampling zone between 15 m and 60 m, a transitional zone, which represents slightly enriched condition before normal one, was observed with additional increase and maintenance of the number of species and density of polychaete. In addition, the potential bio-indicators of organic enrichment, such as Lumbrineris longifolia and Aphelochaeta monilaris were the predominant species in the sampling zone. Multidimensional scaling (MDS) ordination plots and k-dominance curves confirmed the above results on the gradual changes in the macrobenthic polychaete communities. Our findings suggest that the magnitude of impact of fish cage farming activity on polychaete communities is probably governed by a distance from fish cage, density of fish cage and geomorphological characteristics around fish cage farm.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.297-309
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• 2016

This study was carried out to investigate the differences in sedimentary environments and benthic polychaete communities between farming grounds and natural habitats (non-farming ground) in Gamak Bay. Sampling stations of natural habitats were evenly distributed in the entire bay. And mussel farm, oyster farm and ark-shell farm were selected as farming grounds. Dominant sedimentary facies was mud in most sampling stations of farming grounds and natural habitats. However organic contents were higher in the farming grounds than natural habitats of the bay. The species number and mean density of polychaetous community in the natural habitats were greater than those from the farming grounds. Lumbrineris longifolia, known as potential organic enrichment indicator species, was first dominant species both in farming grounds and natural habitats of the bay. However, the next dominant species consisted of different species between two benthic habitats. As a result of community analysis using cluster analysis and nMDS, the natural habitats were divided into several station groups, but most of stations in farming grounds were clustered into one group. Pearson' correlation analysis and PCA showed high relationships between sedimentary environmental factors and benthic polychaetous community in natural habitats, but low or no relationships in farming grounds. That means benthic polychaetous community established in farming ground was under unusual condition such as high input of organic matter. Thus it is necessary to improve the benthic environmental quality of the farming grounds as well as the north-western inner part in Gamak Bay through long-term monitoring efforts.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.67-83
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• 2012

In order to evaluate die geochemical characteristics of sediment in a semi-enclosed bay used as shellfish and fish farming area, the concentrations of metallic(V, Cr, Mn, Fe, Co. Ni, Cu, Zn, Ag, Cd, Hg, Ph, As) and non-metallic(P, Se) elements and uranium were measured in the surface sediment samples collected from 19 stations of Gamak Bay in April 2010. Metal contamination status in the sediments were also evaluated using the sediment quality guidelines(SQGs) proposed by the National Oceanic and Atmospheric Administration(NOAA) and the enrichment factor(EF). The concentrations of elements in sediment were mainly controlled by quartz-dilution effect(V, Cr, Fe, Co and Ni), the dilution effect of organic matter(Cd and U), and metal redistribution by the decomposition of organic matter(Mn, Ag, As, and Se). The concentrations of metals, except As and Ni, in sediments from all sampling stations were lower than ERL values of NOAA. Conclusively, the surface sediment of Gamak Bay was slightly polluted with Ni, Ag, Cd, and Cd but was not polluted with other elements on the basis of EF results. Our results suggest that the surface sediment in Gamak Bay is not polluted by metallic elements.

• Corrosion Science and Technology
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• v.7 no.1
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• pp.50-60
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• 2008

The majority of the described experimental results deal with relatively pure aluminium. Variations were made in the pretreatment of the aluminum substrates and an investigation was performed on the resulting changes in oxide layer composition and chemistry. Subsequently, the bonding behavior of the surfaces was investigated by using model adhesion molecules. These molecules were chosen to represent the bonding functionality of an organic polymer. They were applied onto the pretreated surfaces as a monolayer and the bonding behavior was studied using infrared reflection absorption spectroscopy. A direct and clear relation was found between the hydroxyl fraction on the oxide surfaces and the amount of molecules that subsequently bonded to the surface. Moreover, it was found that most bonds between the oxide surface and organic functional groups are not stable in the presence of water. The best performance was obtained using molecules, which are capable of chemisorption with the oxide surface. Finally, it was found that freshly prepared relatively pure aluminum substrates, which are left in air, rapidly lose their bonding capacity towards organic functional groups. This can be attributed to the adsorption of contamination and water to the oxide surface. In addition the adhesion of a typical epoxy-coated aluminum system was investigated during exposure to water at different temperatures. The coating was found to quite rapidly lose its adhesion upon exposure to water. This rapid loss of adhesion corresponds well with the data where it was demonstrated that the studied epoxy coating only bonds through physisorptive hydrogen bonding, these bonds not being stable in the presence of water. After the initial loss the adhesion of the coating was however found to recover again and even exceeded the adhesion prior to exposure. The improvement could be ascribed to the growth of a thin oxyhydroxide layer on the aluminum substrate, which forms a new, water-stable and stronger bond with the epoxy coating. Two routes for improvement of adhesion are finally decribed including an interphasial polymeric thin layer and a treatment in boiling water of the substrate before coating takes place. The adhesion properties were finely also studied as a function of the Mg content of the alloys. It was shown that an enrichment of Mg in the oxide could take place when Mg containing alloys are heat-treated. It is expected that for these alloys the (hydr)oxide fraction also depends on the pre-treatment and on the distribution of magnesium as compared to the aluminium hydroxides, with a direct impact on adhesive properties.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.421-428
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• 2014

Total 20 surface sediments were collected in Anjung bay to investigate the physicochemical environment and heavy metal contents. The physicochemical investigation ranged from 6.41% to 11.68% (average $9.52{\pm}1.28%$) for ignition loss (IL), from 17.99 mg/g to 43.84 mg/g (average $27.53{\pm}6.39mg/g$) for chemical oxygen demand (COD), and from 0.05 mg/g to 0.61 mg/g (average $0.17{\pm}0.14mg/g$) for acid volatile sulfide (AVS) with significant correlation between water content (W/C) and COD. A contour of spatial distribution indicated higher organic pollution at the bottom of ascidian, Stylea clava, cultural waters. Most of metals contents was not exceeded the NOAA's effect range-low (ERL). Estimated enrichment factor (EF) ranging 0.96-1.12 indicated that the sediment environment of the studied waters was relatively pristine from heavy metal pollution in spite of increased vessel traffics, so far.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.89-91
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• 2000

Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.