• 한국환경보건학회지
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• 제19권4호
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• pp.25-32
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• 1993

Granular activated carbon is commonly used in fixed-bed adsorbers to remove organic chemicals. In this experiment organic chemical solutions were prepared by adding the reagent grade organic chemical to distilled water. Isotherm adsorption tests of volatile organic chemicals were conducted using bottle-point technique and column test. Organic chemicals after passing through the column were extracted with hexane and analyzed with gas chromatography (Hewlett-Packard 5890) to check the adsorption capacity and breakthrough curve. The result were as follows: 1. The BET surface area of coconut activated carbon was 658~1,010 m$^2$/g where as coconut shell carbon was 6.6 m$^2$/g. Coconut activated carbon increased the BET surface area and adsorption capacity in bottle-point isotherm. 2. The adsorption capacity of coconut activated carbon for trichloroethylene (TCE) was reduced in the presence of humic substance. 3. A decrease in particle size of activated carbon resulted in higher adsorption capacity and lower intraparticle diffusion coefficient. It is reflected not only as a decrease in Freudlich adsorption capacity value (K) but also as an increase in Freudlich exponenent value (1/n).

• 한국환경농학회지
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• 제7권2호
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• pp.136-145
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• 1988

도시폐기물의 퇴비화 과정중 퇴비중의 탄소화합물 함량을 시기별로 조사한 결과 다음과 같다. 1. 유기물, 섬유소, 총 탄소, 유기탄소, 미생물 분해가능 탄소 함량은 퇴비화에 따라 감소되었고 리그닌, 미생물 이용 불가능 탄소함량은 약간 증가 되었다. 2. 총 탄소와 미생물 분해가 가능 탄소 함량과 차이는 6.2% 였다. 3. 유기물질의 실제 분해율은 분해율보다 큰 증가 현상을 보였다. 4. 모든 탄소화합물의 실제 분해 능력은 분해능력과 유사하였다. 5. 리그닌의 분해율 및 분해능력은(-)값을 보였으나, 실제 분해율 및 실제분해 능력은(+)값을 가졌다. 6. 퇴비중 유기물, 섬유소, 총탄소, 유기탄소, 미생물 이용 가능 탄소간에 고도의 유의성있는 정의 상관이있었다. 7. 미생물 분해불가능 탄소와 유기물, 섬유소, 총 탄소 유기탄소 및 미생물 분해가능 탄소와는 부의 상관이 있었다. 8. 퇴비중 리그닌과 미생물에 분해 불가능 탄소와도 고도의 정의 상관이 있었다.

• 한국물환경학회지
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• 제28권2호
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• pp.238-246
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• 2012

Organic matters budget in Lake Hoengseong were monthly investigated from April 2009 to November 2009. The intense rainfall occurred at between July and August and the hydrological factors were highly varied during the rainfall season. By the concentrated rainfall, the elevation, influx and efflux were sharply increased and the turbid water was also flowed into the middle water column in Lake. The inflow of turbid water increased the nutrient concentrations in water body and this appears to stimulate of phytoplankton regard as the primary productivity of influx of organic matter. Monthly average concentration of dissolved organic carbon (DOC) was generally higher than the particulate organic carbon (POC) concentration in Lake, but Temporal and spatial variation of POC concentration was higher than DOC and the maximum POC concentration was recorded in surface water in August, had the highest phytoplankton biomass. Organic carbon concentration in inflow site was rarely changed during the dry season, but the concentration was rapidly increased by the initial intense rainfall. In organic matters budget, the most of the organic matters was inflowed from the inflow site at rainfall season. Especially, the influx of allochthonous organic matters during the intense rainfall was 72.4% in the total influx organic matters.

• 수산해양교육연구
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• 제20권1호
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• pp.58-67
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• 2008

Seasonal variations in carbon dioxide in the air and soil organic carbon in the sediments were monitored at the constructed wetland formed by reclamation work at Goheung Bay. Sediment sampling in the constructed wetland and carbon dioxide measurement in the air were conducted on June 16 and August 23, 2007. Sediments in the constructed wetland were sampled at 11 different points (June 16) and 14 points (August 23), while carbon dioxide in the air was measured at 13 points (June 16) and 15 points (August 23). Water content and organic carbon in the sampled sediments were analyzed in the laboratory. Water content of the sediments was higher than that of general soil, and the variation between June and August was not evident. The amounts of organic carbons in the sediments sampled on August 23 were higher than those sampled on June 16. Also, there was more organic carbon in the sediments sampled at the field of reeds than in the pure wetland area. Daily maximum variation in carbon dioxide in the air was higher on June 16, but the amount of carbon dioxide in the air was greater on August 23. The results of the study suggest that organic carbon in the sediments and carbon dioxide in the air were greater in summer (August 23) than in spring season (June 16) in the constructed wetland at Goheung Bay.

• Journal of Ecology and Environment
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• 제37권3호
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• pp.139-145
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• 2014

Denitrification permanently removes nitrate from aquatic ecosystems, so construction of denitrification walls to enhance denitrification activity is often suggested to reduce the nitrate levels from tributary ecosystems. However, little information is available to guide the choice of appropriate organic materials for increasing denitrification rates in the walls. This study investigated how differences in organic substrates originating from litter and organic materials affected denitrification and carbon mineralization rates in riparian sediments. Potential denitrification rates were highest in riparian sediments that contained large quantities of extractable organic carbon (Ext. Org C) and that had high anaerobic carbon mineralization rates, but they were negatively correlated with C:N ratios. Therefore, this research suggested that the both carbon quantity and quality should be considered when assessing the efficiency of organic substrates to remove nitrate from tributary ecosystems.

• 환경생물
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• 제26권3호
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• pp.170-176
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• 2008

월악산 용하계곡에 발달되어 있는 굴참나무림에서 2005년부터 2006년까지 지상부와 지하부 생물량, 낙엽층 그리고 토양의 유기탄소의 분포를 조사하였으며, 탄소수지를 파악하기 위해 토양 호흡량을 측정하였다. 지상부와 지하부 생물량에 분포된 탄소량은 각각 56.22, 13.90 ton C ha$^{-1}$이 었으며, 낙엽층과 토양의 유기탄소량은 각각 4.7 ton C ha$^{-1}$, 119.14 ton C ha$^{-1}$ 50 cm-depth$^{-1}$로, 조사지 굴참나무림의 전체 유기탄소량은 193.96 ton C ha$^{-1}$이었으며, 이중 61.43%의 유기탄소가 토양에 분포하는 것으로 조사되었다. 본 굴참나무림에서 연간 지상부와 지하부 생물량에 의한 유기탄소의 순 증가량은 7.68 ton C ha$^{-1}$ yr$^{-1}$이었으며, 토양호흡을 통해 6.21 ton C ha$^{-1}$ yr$^{-1}$의 유기탄소가 방출되어 본 굴참나무림에서는 연간 대기로부터 1.47 ton C ha$^{-1}$ yr$^{-1}$가 순흡수되는 것으로 조사되었다.

• Carbon letters
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• 제26권
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• pp.102-106
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• 2018

• Ocean and Polar Research
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• 제32권2호
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• pp.145-156
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• 2010

This study investigated organic carbon fluxes in Ulleung Basin sediments, East Sea based on a chamber experiment and geochemical analyses. At depths greater than 2,000 m, Ulleung Basin sediments have high organic carbon contents (over 2.0%). Apparent sedimentation rates (ASR) calculated from excess $^{210}Pb$ activity distribution, varied from 0.036 to $0.047\;cm\;yr^{-1}$. The mass accumulation rates (MAR) calculated from porosity, grain density (GD), and ASR, ranged from 131 to $184\;g\;m^{-2}\;yr^{-1}$. These results were in agreement with sediment trap results obtained at a water depth of 2100 m. Input fluxes of organic carbon varied from 7.89 to $11.08\;gC\;m^{-2}\;yr^{-1}$ at the basin sediments, with an average of $9.56\;gC\;m^{-2}\;yr^{-1}$. Below a sediment depth of 15cm, burial fluxes of organic carbon ranged from 2.02 to $3.10\;gC\;m^{-2}\;yr^{-1}$. Within the basin sediments, regenerated fluxes of organic carbon estimated with oxygen consumption rate, varied from 6.22 to $6.90\;gC\;m^{-2}\;yr^{-1}$. However, the regenerated fluxes of organic carbon calculated by subtracting burial flux from input flux, varied from 5.87 to $7.98\;gC\;m^{-2}\;yr^{-1}$. Respectively, the proportions of the input flux, regenerated flux, and burial flux to the primary production ($233.6\;gC\;m^{-2}\;yr^{-1}$) in the Ulleung Basin were about 4.1%, 3.0%, and 1.1%. These proportions were extraordinarily higher than the average of world open ocean. Based upon these results, the Ulleung Basin might play an integral role in the deposition and removal of organic carbon.

• Journal of the korean society of oceanography
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• 제32권3호
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• pp.103-111
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• 1997

Biogeochemical cycling of organic carbon is quantitatively partitioned in terms of 1) flux to the ocean bottom, 2) benthic utilization at or near the sediment-water interface, 3) remineralization and 4) burial within sediments, by making an independent determination for each component process from a single coastal site in Kwangyang Bay. The partitioning suggests that the benthic utilization at or near the sediment-water interface is the major mode of organic carbon cycling at the site. The benthic utilization takes 61.8% (441.6 gCm$^{-2}$ yr $^{-1}$) of the total near-bottem organic carbon flux, 714.6 gCm $^{-2}$yr$^{-1}$, and far exceeds the remineralization of organic carbon within the sediments which amounts only to 6% (41.24 gCm$^{-2}$yr$^{-1}$) of the total near-bottom flux. The residence time is about 1.6 years for the sedimentary metabolic organic carbon in the upper 45 cm. The dominant partitioning of the benthic utilization in the carbon budget suggests that most of labile organic carbons are consumed at or near the sediment-water interface and are left over to the sediment column by significantly diminished amounts.

• 한국산업보건학회지
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• 제6권1호
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• pp.55-66
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• 1996

This study was conducted to evaluate breakthrough characteristics of respirator cartridge using multi-organic vapors, including carbon tetrachloride, trichloroethylene, and toluene. The organic vapors were used as single phase, binary system, and ternary system. The results are summarized as follows. 1. Organic vapors studied were 1,000 ppm, 750 ppm, 500 ppm and 250 ppm in single phase. Carbon tetrachloride having the highest molecular weight showed the breakthrough first, and breakthrough sequency by organic vapor was dependent on its molecular weight. The 10% breakthrough times at 1,000 ppm of organic vapor were 97 minutes for carbon tetrachloride, 129 minutes for trichloroethylene and 135 minutes for toluene. 2. When concentrations of organic vapors were at levels of the Threshold Limit Values, the lives of the respirator cartridges were 122 hours in carbon tetrachloride, 18 hours in trichloroethylene and 28 hours in toluene. 3. In the binary system at a total concentration of 1,000 ppm with carbon tetrachloride and trichloroethylene, breakthrough times ranged from 104 minutes to 125 minutes, which were longer than 97 minutes in a single phase (1,000 ppm) for carbon tetrachloride, but shorter than breakthrough times for TCE and Toluene. 4. Breakthrough times in the binary system with carbon tetrachloride and toluene were 131~132 minutes. 5. Breakthrough times in the ternary system with carbon tetrachloride, toluene, and trichloroethyl ene were $120{\pm}8$ minutes, which were longer than 97 minutes in the single phase (1,000 ppm) for carbon tetrachloride, equal to 129 minutes for trichloroethylene, and shorter than 135 minutes for toluene. Those were almost similar to $124{\pm}9$ minutes of breakthrough times in the binary systems.