• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.180-186
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• 2005

This paper discusses the development of mixtures for silica fume as a stabilization/solidification agent and a binder for industrial wastewater residue containing organic and heavy metal contaminants. The UCS (unconfined compressive strength) gradually increased to 66.7% as the silica fume content increased to 15%. The leaching of TOC (total organic carbon) and chromium decreased as more OPC (Ordinary Portland Cement) was substituted with the silica fume. When a mixture had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution. Also, microstructural studies of the solidified analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contrilbute to setting but coated the cement particles and retarded the setting reactions. The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and the contaminant leachability.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.4
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• pp.164-173
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• 2004

Field survey on the marine environmental characteristics by the distribution of dinoflagellate cysts and organic matter was carried out bimonthly at 6 stations in Gamak Bay, the southern part of Korean Peninsula from June 2000 to April 2001. The range of environmental factors on vertical sediments such as ignition loss (IL), chemical oxygen demand (CODs), total sulfide (H₂S), particulate organic carbon (POC), particulate organic nitrogen (PON) and phaeopigment were 3.21∼11.18％. 12.25∼99.26 mgO₂/g dry, 2.49∼116.18 ㎍/g dry, 2.91∼116.18 mgC/g dry, 0.53∼2.82 mgN/g dry and 2.49∼116.18 ㎍/g dry, respectively. A total of 38 species dinoflageuate cysts belonged to 21 genera, 36 species, and 2 unidentified species. A cysts density were 18∼3,836 cysts/g dry. Vertical distribution of organic matter and dinoflagellate cysts was rapidly decreased from surface to deeper sediment. The eutrophication in the northwestern parts of Gamak Bay might originated since 1980s.

• 한국해양학회지
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• v.29 no.2
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• pp.107-118
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• 1994

An investigation of the annual change and C:N:P ratio in particulate organic matter (POM) in Chinhae Bay, a semi-enclosed bay of the southern coast of Korean Peninsula, was carried out for a period of 12 months between January and December, 1993. The concentrations of POM have a broad range: 198∼4,416 ugC/l, 24∼792 ugN/l and 4.5∼69.0 ugP/l, Marked seasonal changes of POM, particularly particulate organic carbon (POC) and nitrogen (PON), were observed in the surface water. Generally, the concentration of POM peaks in summer. The C:N:P composition ratio of particulate organic matter, which is high in summer, also shows a seasonal change. The C:N assimilation ratio is constant at 6.53, which is consistent with the Redfield ratio. The significant linear relationship between POM and chlorophyll-a in the surface water during the survey period (except for January and February) and the C:N ratio suggest that the concentration of POM is controlled by phytoplankton biomass. POM peaks in summer, a period characterized by high freshwater input and the strong stratification, as a result of the intense proliferation of phytoplankton by a large amount of nutrient loading from the tributaries. On the other hand, the high C:P and N:P ratios in summer indicate that P is limited for phytoplankton growth owing to N-enrichment from a high input of freshwater with a high dissolved inorganic N:P ratio.

• Particle and aerosol research
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• v.7 no.4
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• pp.131-138
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• 2011

The concentration levels of n-alkanes and water soluble organic carbon (WSOC) at Anmyon, a Global Atmospheric Watch (GAW) station operated by Korea Meteorological Administration (KMA), has been characterized for the PM10 samples collected in 2010. It was found that the concentrations of WSOC at Anmyon were comparable to those in Seoul and lower than those in Gosan, another background area in Korea. However, the maximum concentration of the WSOC at Anmyon was observed in fall while that at Seoul was in winter. It suggests that the emission and/or transformation characteristics at two areas are different. The concentrations of n-alkanes at Anmyon were slightly lower than at Gosan and about one thirds at Seoul. However, it was found that at Gosan the n-alkanes from natural sources were dominant at Gosan. On the other hand, n-alkanes from anthropogenic sources were dominant at Anmyon. Study directions to further understand the characteristics of aerosols at Anmyon are discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.442-450
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• 1997

The chemical properties of water masses were investigated at 33 stations of the southeastern last Sea in February, 1995 on board R/V Tam-Yang. The water masses were not clearly distinguished due to the vortical mixing in winter. However, on the basis of the T-S and $T-O_2$ diagrams, water masses in the study area were divided into five groups (Type I, Type II, Type III, Type IV, Type V). (1) $>9.0^{\circ}C,\;>34.35\;psu,\;5.08\~5.60m\ell/\ell$ at Type I, (2) $6.0\~9.0^{\circ}C,\;34.15\~34.35\;psu,\;5.60\~5.90\;m\ell/\ell$ at Type II, (3) $4.0\~6.0^{\circ}C,\;34.00\~34.15\;psu,\;>5.90m\ell/\ell$ at Type III, (4) $1.5\~4.0^{\circ}C,\;34.00\~34.05\;psu,\;5.40\~5.90\;m\ell/\ell$ at Type IV, (5) $<1.5^{\circ}C,\;34.05\~34.07\;psu,\;4.80\~5.40\;m\ell/\ell$ at Type V. In the vertical profiles of nutrients, the concentrations were very low in the surface layer and increased rapidly with depth. The highest concentrations occurred in Type IV, while the concentrations in Type I were the lowest. The N/P ratios were less than Redfield ratio, indicating that nitrogenous nutrients were the limiting factor tor phytoplankton growth. The concentrations of POC and PON were in the range of $0.49\~20.03\;{\mu}g-at/\ell\;and\;0.09\~5.34\;{\mu}g-at/\ell$, respectively. The relatively high concentration occured in the surface layer of inner shore, showing that the concentration at each water mass followed the order Type I > Type II > Type III > Type IV > Type V, respectively. The C:N ratio in particulate organic matter was lower than the values reported in other region due to relatively high concentrations of PON in the study area. Relatively high ratios of POC to chlorophyll $\alpha$ during the study periods indicate that non-living detritus comparised most of the POC in the study area.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.197-197
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• 2010

음식물쓰레기의 삼성분은 수분, 휘발분, 회분이며 이들이 차지하는 비율은 계절, 지역별로 다소 상이하지만 수분 약 80%, 회분3%, 휘발분 17%이다. 음식물쓰레기 전처리과정으로 이물질제거, 탈수공정이 있으며 탈수공정에서 다량의 탈리액이 발생한다. 본 연구에서는 탈리액을 데칸타를 이용하여 1차로 원심분리하여 고.액 분리한 액을 실험대상으로 하였다. 실험대상 탈리액의 물성은 BOD 78,800[mg/l], COD 41,000[mg/l], 부유물질 25,900[mg/l], 총질소 928[mg/l]이었다. 탈리액에는 기름성분(육류, 식용유등), 입자상물질등이 포함되어 있으며 이들은 난분해성 유기물질로, 이를 제거하는데 기존의 처리방법으로 많은 어려움이 있어 주요한 수질오염 발생원이 되고 있다. 예를들면 하수처리장 폭기조 수면에 유막을 형성하여 산소공급을 방해함으로 미생물번식을 방해하는 요인이 된다. 본 연구는 음식물쓰레기 탈리액의 수분, 고형분, 유분으로의 삼상분리에 관한 것이다. 유분은 에멀젼형태로 안정되게 수층에 분산되어 존재한다. 미세기포를 이용한 부상법의 경우 미세기포 표면과 유분의 화학적친화력이 낮아 기포표면에 유분이 잘 부착되지 않으며, 원심분리 방법만으로는 유분 분리효율이 낮고, 추출에 의한 분리시 추출액이 다량 소요되고 처리시간이 길며 추출액 비용이 많이 소요된다. 탈리액을 유분, 슬러지, 수분으로 분리하면 환경오염을 일으키는 주요성분을 신재생에너지 원료로 활용할 수 있다. 유분의 주성분이 동식물성 유지이므로 전처리시 산촉매를 이용 수분과 유리지방산을 제거하고 염기성촉매를 이용하여 전이에스테르화 반응을 거치면 바이오디젤인 FAME과 글리세롤으로 변환하므로 글리세롤을 분리하면 바이오디젤을 얻을 수 있다. 슬러지는 입자상 물질로 착화가 잘 되고 건조하면 발열량이 높으며 중금속등에 오염되지 않아 청정연료로 활용이 가능하다. 실험실에서의 탈리액 삼상분리방법은 다음과 같다. 탈리액 30ml당 추출액으로 노말헥산을 1ml를 가한 다음 플라스크에서 $80^{\circ}C$로 가열 후 방냉한다. 가열중 노말헥산의 손실을 방지하기 위하여 증발가스를 콘덴서에서 응축하여 플라스크로 재순환한다. 탈리액을 플라스크에서 꺼내어 원심분리기 rack에 300-400g씩 병에 각각 넣고 4,000rpm으로 30분간 운전한다. 탈리액은 상부로부터 유분층, 미세입자층, 수층, 슬러지층으로 분리된다. 각 층의 계면에서 2종의 성분이 약간 섞일 수 있다. 유분을 분리한 후 유분층 잔존물과 미세입자층, 수층 상층부의 혼합물을 취하여 50g씩 병에 넣고 3,500rpm으로 10분간 운전한 후 유분을 분리한다. 마지막으로 미세입자층만을 3,500rpm으로 10분간 원심분리한 후 유분을 따로 분리한다. 얻어진 유분은 rotary evaporator에서 $120^{\circ}C$로 가열하여 유분과 노말헥산을 분리하며 분리효율을 제고하기 위하여 감압하에서 운전한다. 분리된 유분의 고위발열량이 9,450[Kcal/kg]이었으며 원소분석 결과 탄소 74.7%, 수소 12.55%, 질소 0.08%, 유황분 0.0003%이었다. 분리된 유분의 양은 계절별로 시료별로 다르며 가을철에는 1.6-1.9%, 여름철은 1.0-1.3%이었다. 분리된 슬러지로부터 Hg, As, Cr, Cd, Pb 중금속 성분이 검출되지 않았으며 수분 2.8%, 휘발분 76.85%, 회분 7.52%, 고정탄소 12.83%이었고 원소분석결과 탄소 45.25%, 수소 7.46%, 질소 5.05%, 산소 34.39%, 유황분 0.33%이었으며 저위발열량은 4,480[Kcal/kg]이었다. 분리된 슬러지 양은 11-19% 이었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.220-227
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• 2016

In this paper, polychlorinated biphenyls (PCBs) were measured in surface sediments collected three times (June, October, December, 2013), inside Jeju Harbor as major harbors of Jeju Island. The concentration of PCBs inside Jeju Harbor was in the range of 1.62~4.45 (mean) ng/g on a dry weight basis and the levels were very low. In the analysis of PCBS homologue patterns, high-chlorinated PCB congeners were dominant in surface sediments inside Jeju Harbor, indicating that their sources were originated from shipping activity. In the relationships between PCBs concentrations and particle size (mud, sand and gravel) in surface sediments, PCBs concentrations were higher in the sediments with higher mud content, indicating that higher PCBs were distributed with increasing sediments of fine gradules. The PCBs concentrations in surface sediments in this study were very low, compared with ER-L (effect range-low) and TEL (threshold effects level) among sediment quality guideleines (SQGs) applied in foreign countries, such as USA, Canada, and Australia, etc), indicating that their biological effects on the bottom organisms in marine environment were expected to be very low.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.11-20
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• 2015

In the present work, a basic study on the in-situ biogenic methane generation from low grade coal bed was conducted. Lignite from Indonesia was used as a sample feedstock. A series of BMP (Biochemical Methane Potential) tests were carried out under the different experimental conditions. Although nutrients and anaerobic digester sludge were added to the coal, the produced amount of methane was limited. Both temperature control and particle size reduction showed little effect on the increase of methane potential. When rice straw was added to lignite as an external carbon source, methane yield of 94.4~110.4 mL/g VS was obtained after 60 days of BMP test. The calorific value of lignite after BMP test decreased (4.5~12.1 %) as increasing the content of rice straw (12.5~50 wt % of lignite), implying that anaerobic digestion of rice straw led to partial degradation of lignite. Therefore, rice straw could be used as an external carbon source for the start-up of in-situ biogas generation from low grade coal bed.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.163-172
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• 2005

Field survey on the marine environmental characteristics by the distribution of dinoflagellate cysts and organic matter carried out bimonthly at 14 stations in the central parts of South Sea, Korea from April 2002 to January 2003. The range of environmental factors on surface sediments such as water content, ignition loss (IL), chemical oxygen demand (CODs), particulate organic carbon (POC), particulate organic nitrogen (PON) and phaeopigment were $38.7\~68.9\%,\;3.9\~12.5\%,\;9.60\~44.05mgO_2\;gdry^{-1},\;3.12\~13.14mgC\; gdry^{-1},\;0.49\~2.01mgN\;gdry^{-1}\;and\;1.61\~29.51{\mu}g\;gdry^{-1}\;gdry-1$, respectively. A total dinoflagellate cysts identified were 33 species, which belonged to 18 genera,31 species, and 2 unidentified species. A cysts density were $42\~2,880\; cysts\;gdry^{-1}$. The dominant species of dinoflagellate cysts were Spinrferites bulloideus and Scrippsiella trochoidea all the year and autotrophic species was more abundant than heterotrophic species. The organic matter and dinoflgellate cysts were more abundant nearshore than offshore, and the origin of organic matter was autochthonous rather than from terrestrial. The two factors derived from the loading factor of PCA. Factor 1 was 'accumulation of oragnic matter in the offshore', factor 2 was 'cysts abundance', and the central parts of Korean South Sea was separated with 3 regions by score distribution of PCA.

• 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.