• Journal of the Korean Wood Science and Technology
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• 제47권3호
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• pp.277-289
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• 2019

Herein, a case study discussing the effect of carbonaceous aerosol pollution, which is emitted during the charcoal kiln manufacturing processes or carbonization processes, on the atmospheric environment is presented . In South Korea, in situ analysis of different charcoal production plants specialized in the production of charcoal sauna indicate that the emitted organic carbon (OC) and elemental carbon (EC) aerosols are significantly influenced by the nature of the biomass and technological processes, i.e., treatment or emissions abatement systems for the exhaust effluent gases. In detail, total carbon (TC), which is calculated as the sum of OC and EC emission factors, varied widely from a charcoal production site to another ranging from 21.8 to 35.8 gTC/kg-oak, where the mean value for the considered production sites was approximately 28 gTC/kg-oak (N = 7 and sum = 196.4). Results indicate that the emission factors from a modern charcoal production process in South Korea are quantitatively lower in comparison with the traditional kiln. This study aims to propose advanced wood processes for the production of charcoal from the viewpoint of environmental protection policy and green engineering.

• 한국환경과학회지
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• 제12권11호
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• pp.1173-1179
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• 2003

Laboratory sorption isotherm batch studies have been attempted to elucidate interaction of synthetic pyrethroids (bifenthrin and permethrin) with sediments and their fractions. As a nonlinear isothermal model, the Freundlich equation was applied to sorption results obtained from sediments to investigate the relationship between synthetic pyrethroids and sediments containing different amounts of organic carbon. Results demonstrated that the sorption capabilities of bifenthrin and cis- and trans-permethrin was in the order of bifenthrin, cis-permethrin and trans-permethrin, respectively, indicating that adsorbed bifenthrin was the most stable followed by cis- and trans-permethrin in all sediments. Their sorption capability was closely related to organic carbon contents in sediments. Higher sorption was observed in sediments containing higher organic carbon contents. Sorption study extended into the fractions, clay and humic acids, extracted from a sediment, indicated that higher sorption capacity in humic acids occurred than in the clay of both examined bifenthrin and permethrin. This study demonstrates the sorption of synthetic pyrethroids with sediments, and will help in the understanding of the transport and fate of synthetic pyrethroids existing in field sediments.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.16-19
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• 2006

Humin is the insoluble fraction of humic materials and play an important roles in the irreversible sorption of hydrophobic organic contaminants onto soil particles. However, there have been limited knowledge about the sorption and chemical properties of humin due to the difficulties in its separation from the inorganic matrix(mainly clays and oxides). In this study, do-ashed humin was isolated from a soil sample after removing free lipid and alkali-soluble humic fractions followed by dissolution of mineral matrix with 2% HF, and characterized by elemental analysis, C-13 NMR spectroscopic method. Sorption behavior of 1-naphthol with humin was also investigated from aqueous solution. C-13 NMR spectra indicate that humin molecules are mainly made up of aliphatic carbon including carbohydrate, methylene chain etc.. Sorption intensity for 1-naphthol was increased as organic carbon content of humin increased and log Koc values for the 1-naphthol sorption were determined to be ${\sim}3.12$

• 농업과학연구
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• 제44권1호
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• pp.16-22
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• 2017

An experiment was conducted to detect aquaculture pond bottom soil nutrients, pH and electrical conductivity with a view to optimize production and to incorporate the scientific method of fish nursing, rearing and culturing at Noakhali district in Bangladesh. The soil samples were collected from the recently dug ponds (1 - 5 years) and older ponds (> 5 years). Samples were taken from five different spots in a Z shape from each pond and were mixed to get a composite sample. The composite samples from the ponds were collected in polyethylene bags and shipped to the laboratory for analysis. The soil samples were analyzed with respect to pH, electrical conductivity (EC), organic carbon (OC), organic matter (OM), nitrogen (N), phosphorous (P), potassium (K) and sulfur (S). The average value of pH, OC, OM, N, P, K and S were $7.43{\pm}0.40$, $2.21{\pm}1.43%$, $1.47{\pm}0.53%$, $2.52{\pm}0.94{\mu}g\;g^{-1}$, $0.126{\pm}0.047{\mu}g\;g^{-1}$, $3.84{\pm}1.77{\mu}g\;g^{-1}$, $0.191{\pm}0.106{\mu}g\;g^{-1}$ and $306.72{\pm}222.05{\mu}g\;g^{-1}$ respectively, in Noakhali. The average EC, OC, OM, N and P contents were found to be higher in Subornachar than those in Sonapur. On the other hand pH, K and S were found to be higher in Sonapur than the values of Subornachar. The pH, EC, OC, OM, N and S contents were found to be higher in new ponds than old ponds whereas P and K contents were found to be higher in old pond than in new pond.

• 센서학회지
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• 제30권5호
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• pp.320-325
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• 2021

Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) methods are conventional analytical methods to analyze water quality. Both of these methods are technically indirect measurement methods, require complicated preconditions, and are time-consuming. On the other hand, the total organic carbon (TOC) method is a direct and fast measurement method which is more intuitive and accurate than the BOD and COD methods. However, general TOC analysis methods involve complicated processes and high power consumption owing to the process of phase transition from liquid to gas by a high-temperature heater. Furthermore, periodic consumables are also required for the removal of inorganic carbon (IC). Titanium dioxide (TiO₂) is one of the most suitable photocatalysts for simple processes. Its usage involves low power consumption because it only reacts with the organic carbon (OC) without the requirement of any other reagents and extra processes. We investigated a TiO₂ photocatalyst-based TOC analysis for simple and affordable products. TiO₂-coated fiber substrate maintained under carbon included water was exposed to ultraviolet (UV) radiation of wavelength 365 nm. This method is suitable for the real-time monitoring of water pollution because of its fast reaction time. Its linear property is also sufficient to match the real value.

• 한국대기환경학회지
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• 제32권6호
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• pp.633-641
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• 2016

Two identical Particle Into Liquid Samplers-Total Organic Carbon (PILS-TOC) were operated to measure fine particle Water Soluble Organic Carbon (WSOC) for one week on Feb. in 2016. The dual instrument operations provided validated WSOC concentrations to have a continuous WSOC measurement during the sample analysis period. Both PILS-TOC instruments were operated downstream of an carbon denuder to remove positive adsorption artifacts associated with semi-volatile organic compounds. Comparison of WSOC showed good agreement each other. The linear regression had a coefficient of determination ($r^2$) of 0.92 and a regression slope of 1.01 for the first period. The lower collection efficiency due to lower steam temperature is discussed. In addition, the potential primary source related to WSOC based on the comparison of black carbon (BC) concentrations is explained. The results of good agreement between two PILS-TOC measurements can provide the validation of WSOC cooperations and knowledge regarding the origins of WSOC and their behaviors.

• 한국환경과학회지
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• 제25권10호
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• pp.1349-1368
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• 2016

Concentrations of fine particulate matter ($PM_{2.5}$) and several of its particle constituents measured outside homes in Houston, Texas, and Los Angeles, California, were characterized using multiple regression analysis with proximity to point and mobile sources and meteorological factors as the independent variables. $PM_{2.5}$ mass and the concentrations of organic carbon (OC), elemental carbon (EC), benzo-[a]-pyrene (BaP), perylene (Per), benzo-[g,h,i]-perylene (BghiP), and coronene (Cor) were examined. Negative associations of wind speed with concentrations demonstrated the effect of dilution by high wind speed. Atmospheric stability increase was associated with concentration increase. Petrochemical source proximity was included in the EC model in Houston. Area source proximity was not selected for any of the $PM_{2.5}$ constituents' regression models. When the median values of the meteorological factors were used and the proximity to sources varied, the air concentrations calculated using the models for the eleven $PM_{2.5}$ constituents outside the homes closest to influential highways were 1.5-15.8 fold higher than those outside homes furthest from the highway emission sources. When the median distance to the sources was used in the models, the concentrations of the $PM_{2.5}$ constituents varied 2 to 82 fold, as the meteorological conditions varied over the observed range. We found different relationships between the two urban areas, illustrating the unique nature of urban sources and suggesting that localized sources need to be evaluated carefully to understand their potential contributions to $PM_{2.5}$ mass and its particle constituents concentrations near residences, which influence baseline indoor air concentrations and personal exposures. The results of this study could assist in the appropriate design of monitoring networks for community-level sampling and help improve the accuracy of exposure models linking emission sources with estimated pollutant concentrations at the residential level.

• 한국대기환경학회지
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• 제31권4호
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• pp.330-344
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• 2015

Semi-continuous measurements of $PM_{2.5}$ mass, organic and elemental carbon were made for the period of January to October 2014, at six national air monitoring stations in Korea. OC and EC concentrations showed a clear seasonal variation with the highest in winter (January) and the lowest in summer (August). In winter, the high carbonaceous concentrations were likely influenced by increased fuel combustion from residential heating. OC and EC concentrations varied by monitoring stations with 5.9 and $1.7{\mu}g/m^3$ in Joongbu area, 4.2 and $1.2{\mu}g/m^3$ in Honam area, 4.0 and $1.3{\mu}g/m^3$ in Yeongnam area, 3.7 and $1.6{\mu}g/m^3$ in Seoul Metropolitan area, 3.0 and $0.8{\mu}g/m^3$ in Jeju Island, 2.9 and $0.7{\mu}g/m^3$ in Baengnyeong Island respectively. The concentrations of OC and EC comprised 9.6~ 15.5% and 2.4~ 4.7% of $PM_{2.5}$. Urban Joongbu area located adjacent to the intersection of several main roads showed the highest carbon concentration among six national air monitoring station. On the other hand, background Baengnyeong Island showed the lowest carbon concentration and the highest OC/EC ratio (4.5). During the haze episode, OC and EC were enhanced with increase in $PM_{2.5}$ about 1.3~ 3 and 1.3~ 4.0 times respectively. The concentrations of OC, EC in the Asian dust case are about 1~ 2.4 times greater than in the nondust case. The origins of air mass pathways arriving at Seoul, using the backward trajectory analysis, can be mostly classified into 6 groups (Sector I Northern Korea including the sea of Okhotsk, Sector II Northern China including Mongolia, Sector III Southern China, Sector IV South Pacific area, Sector V Japan, Sector VI Southern Korea area). When an air mass originating from northern China and Mongolia, the OC concentrations were the most elevated, with a higher OC/EC ratio (2.4~ 3.3), and accounting for 17% of $PM_{2.5}$ mass on average.

• Journal of the korean society of oceanography
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• 제34권1호
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• pp.36-42
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• 1999

To assess present status of polychlorinated biphenyls (PCBs) contamination in Kyeonggi Bay, Namyang Bay, and Lake Shihwa, 63 sediment samples were analyzed and applied to equilibrium partitioning approach. Sediment quality criteria (SQC) for exposure to Kanechlor mixture (KC-mix) was calculated as a value of 16 ${\mu}$g/g-organic carbon (OC). Two sites (Sites Kl8 and Kl9) within Incheon North Harbor (INH) with total PCBs concentrations 48 and 38 ${\mu}$g/g-OC, respectively, exceeded SQC, indicating a potential of adverse biological effects. The advantage and disadvantage of equilibrium partitioning approach has been discussed.

• 분석과학
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• 제25권2호
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• pp.133-145
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• 2012

대기 중의 총부유먼지(total suspended particulate, TSP)를 구성하는 성분들 중 organic carbon (OC), element carbon (EC), 금속성분은 양적으로 중요한 구성인자에 해당한다. 이들을 제외한 나머지 부분은 아직까지 정성 및 정량분석이 취약한 미지 물질(${\Sigma}X$)에 해당한다. 본 연구에서는 서울시 강서 지역에서 2009년 2-12월 기간동안 관측한 자료를 이용하여, TSP의 주요 성분들 간의 관계에 대한 분석을 시도하였다. 이를 통해, TSP의 거동을 다양한 각도에서 해석하기 위한 기초 자료로 활용하고자 하였다. 전체 연구기간 동안, TSP를 이루는 주요인자로서 미지의 영역이 평균적으로 48.6%를 차지할 정도로 더 지배적이란 것을 확인하였다. 그리고 TSP에 대한 그 구성 성분들간의 관계를 검토하였을 때, 미지 물질들은 이온성분들과 밀접한 연관성을 보일뿐 아니라 TSP의 함량과 정비례 관계임을 확인하였다. 반면, 양자를 TSP의 농도로 표준화(normalization)를 하였을 경우, 뚜렷한 반비례 관계에(강한 역상관성)이 두드러지게 나타났다. 이러한 현상은 ${\Sigma}X$가 이온성분과는 달리 수용성이 떨어지는 특성을 지닌 것을 반영한 것으로 사료된다. TSP의 거동을 보다 체계적으로 이해하고 이를 도시 대기질 관리에 적용하기 위해서는, ${\Sigma}X$의 조성이나 거동을 명확하게 규정하기 위한 여러 가지 연구가 필요하다.