• Asian Journal of Atmospheric Environment
• /
• v.6 no.1
• /
• pp.67-72
• /
• 2012

The chemical characterization of water-soluble organic carbon in ash emitted from a coal combustion boiler has not been reported yet. A total of 5 ash samples were collected from the outlet of an electrostatic precipitator in a commercial 500 MW coal-fired power plant, with their chemical characteristics investigated. XAD7HP resin was used to quantify the hydrophilic and hydrophobic water-soluble organic carbons (WSOC), which are the fractions of WSOC that penetrate and remain on the resin column, respectively. Calibration results indicate that the hydrophilic fraction includes aliphatic dicarboxylic acids and carbonyls (<4 carbons), amines and saccharides, while the hydrophobic fraction includes aliphatic dicarboxylic acids (>4-5 carbons), phenols, aromatic acids, cyclic acid and humic acid. The average mass of the WSOC in the ash samples was found to depend on the bituminous coal type being burned, and ranged from 163 to 259 ${\mu}g$ C/g of ash, which corresponds to 59-96 mg C of WSOC/kg of coal combusted. The WSOC mass accounted for 0.02-0.03 wt% of the used ash sample mass. Based on the flow rate of flue gas produced from the combustion of the blended coals in the 500 MW coal combustion boiler, it was estimated that the WSOC particles were emitted to the atmosphere at flow rates of 4.6-7.2 g C/hr. The results also indicated that the hydrophilic WSOC fraction in the coal burned accounted for 64-82% of the total WSOC, which was 2-4 times greater than the mass of the hydrophobic WSOC fraction.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.1
• /
• pp.31-37
• /
• 2002

This paper was investigated to clarify the possibility of a biodegradation of materials adsorbed on different porous granular-activated carbons (GACs) such as coal-& coconut-based GAC. Total organic carbon, humic substance and ammonia were used to compare their removal efficiencies. The objective of this study is to determine the adsorption capacity of bioregenerated GAC. When raw water reacted with chloride, the yield of THMs increased as a function of the input amount of chloride. The formation of trihalomethanes (THMs) was investigated in water treated with chlorine when humic acid was used as THM precursor. As the input amount of chloride in raw water increased by two or five-fold to remove the $NH_3$, the chloroform of the THMs significantly increased also five or ten-fold. It was found that the chloroform was significantly removed by the treatment of biological activated carbon (BAG) in comparison with the ozone treatment, and the removal efficiency of THMs in coal-typed GAC was $10-30\%$ better than coconut-typed GAC due to the biological degradation on the surface of the activated carbons.

• Clean Technology
• /
• v.16 no.1
• /
• pp.33-38
• /
• 2010

The characteristics of desorption reaction and the heating values of used activated carbons collected from the companies of Shiwha/Banwal industrial complex were investigated. The desorption characteristics of used activated carbons were analyzed based on the data obtained from a thermogravimetric analyzer. The activation energies and reaction orders for desorption reaction of used activated carbons were calculated by employing Freeman-Carroll method. Heating values of volatile organic compounds(VOC) desorbed from used activated carbons were estimated based on the data obtained from a total hydrocarbon analyzer. It was found that the reaction orders of desorption of used activated carbons were 0.1~0.8, their desorption activation energies, 6.9~26.4 kJ/mol, and VOC heating values, 0.4~10.7 kcal/kg.

• Journal of the korean society of oceanography
• /
• v.32 no.3
• /
• pp.103-111
• /
• 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.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.2 no.1
• /
• pp.69-78
• /
• 1998

Contents of heavy metals (Cr, Cu, Zn, Cd, and Pb) in the sediments of Ulsan Bay were investigated by the sequential extraction methods that classifies heavy metals into five types of chemical forms: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. The analytes were determined by using an ICP-MS. Total Cr concentrations in the sediments were in the range of 41.6-96.4, Cu 60.7-680, Zn 189-1954, Cd 33.1-83.4, and Pb 138-567 mg/kg. Results of sequential fractionation indicates that relatively high proportion $(\~44\%)$ of Cu is associated with organic matter A large proportion of Pb is associated with three types of chemical forms: Fe-Mn oxides, organic matter, and residual. There were significant correlation in concentrations between the exchangeable components and total organic carbons. The heavy metals in the residual phase cannot be easily released to the environment since these are bound to the crystal lattice. But, reducible and organic Phases cfn a significant amount of most heavy metals. Therefore. there is potential danger of a substantial amount of metals becoming chemically mobile with environmental changes.

• Journal of Korean Society for Atmospheric Environment
• /
• v.30 no.5
• /
• pp.461-476
• /
• 2014

Continuous Water-Soluble Organic Carbons (WSOC) by the Particle Into Liquid Sampler - Total Organic Carbon (PILS-TOC) analyzer were measured at the Seoul intensive monitoring site from June 17 through July 5 in 2014. In addition, the 24 hour integrated PM2.5 collected by Teflon and Quartz filters were analyzed for water soluble ions by Ion chromatography (IC), WSOC by TOC from water extracts, organic carbon (OC), elemental carbon (EC) by carbon analyzer using the thermal optical transmittance (TOT) method, and mass fragment ions (m/z) related to alkanes and PAHs (Poly Aromatic Hydrocarbons) by Gas Chromatography-Mass Spectrometer-Thermal Desorption (GC/MS-TD). Based on the statistical analysis, four different Carbonaceous Thermal Distributions (CTDs) from OCEC thermal-gram were identified. This study discusses the primary and secondary sources of WSOC based on the Classified CTD, organic mass fragments, and diurnal patterns of WSOC. The results provide knowledge regarding the origins of WSOC and their behaviors.

• Journal of Environmental Science International
• /
• v.2 no.1
• /
• pp.69-78
• /
• 1993

Contents of heavy metals (Cr, Cu, Zn, Cd, and Pb) in the sediments of Ulsan Bay were investigated by the sequential extraction methods that classifies heavy metals into five types of chemical forms: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. The analyses were determined by using an ICP-MS. Total Cr concentrations in the sediments were in the range of 41.6-96.4, Cu 60.7-680, Zn 189-1954, Cd 33.1-83.4, and Pb 138-567 mg/kg. Results of sequential fractionation indicates that relatively high proportion ( ~44%) of Cu is associated with organic matter. A large proportion of Pb is associated with three types of chemical forms: Fe-Mn oxides, organic matter, and residual. There were significant correlation in concentrations between the exchangeable components and total organic carbons. The heavy metals In the residual phase cannot be easily released to the environment since these are bound to the crystal lattice. But, reducible and organic Phases con a significant amount of most heavy metals. Therefore, there is Potential dancer of a substantial amount of metals becoming chemically mobile with environmental changes.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.4
• /
• pp.496-501
• /
• 2012

Thirty-five available feeds were fermented in vitro in order to investigate their soluble total organic carbon (TOCs) and methane ($CH_4$) production rate. A fermentation reactor was designed to capture the $CH_4$ gas emitted and to collect liquor from the reactor during in vitro fermentation. The results showed that $CH_4$ production rate greatly varied among feeds with different ingredients. The lowest $CH_4$-producing feeds were corn gluten feed, brewer's grain, and orchard grass among the energy, protein, and forage feed groups, respectively. Significant differences (p<0.05) were found in digestibility, soluble total organic carbon (TOCs), and $CH_4$ emissions among feeds, during 48 h of in vitro fermentation. Digestibility and TOCs was not found to be related due to different fermentation pattern of each but TOCs production was directly proportional to $CH_4$ production (y = 0.0076x, $r^2$ = 0.83). From this in vitro study, TOCs production could be used as an indirect index for estimation of $CH_4$ emission from feed ingredients.

• Journal of Korean Society for Atmospheric Environment
• /
• v.13 no.3
• /
• pp.179-191
• /
• 1997

The concentrations of organic and elemental carbon were determined using fine particle samples collected from Kosan, Cheju Island during the summer seasons of 1994 and 1995. The daily mean concentrations of organic and elemental carbon for each measurement period were 3.74 and 0.27 $\mu\textrm{g}$/㎥ in 1994, while those of 1995 were 2.36 and 0.10 $\mu\textrm{g}$/㎥, respectively The concentrations of organic carbon were higher than those commonly observed from clean areas around the world, but those of elemental carbon were lower than, or comparable to, other clean areas in the world. The resulting ratios of total carbon to elemental carbon at this site were thus higher than those seen from other metropolitan and non-polluted regions abroad. In addition according to our analysis, the 1994 measurement period can be classified into two periods: enhanced (July 20 and August 1) and reduced levels (August 2 and 9) of the carbonaceous species. The observed difference between two periods may be in part accounted for by the air trajectories representing each period. During the former period, the air masses from the Asian continent and Japan were dominant, while the air masses from the North Pacific Ocean came during the latter period. OC/EC ratios at the site were calculated to predict the possible formation of secondary organic aerosol . Based on our observations, we suggest that the formation of secondary organic aerosol might be an important pathway to the production of organic carbons.

• Applied Chemistry for Engineering
• /
• v.21 no.6
• /
• pp.680-683
• /
• 2010

Nano carbon balls (NCBs), activated carbons (ACs) and their mixture (new carbon mixtures, NCMs) were used to reduce volatile organic compounds (VOCs) emitted from the automobile felt. The optimum analytical method to measure the trace amount of the VOCs, including formaldehyde and acetaldehyde, has been established by utilizing high performance liquid chromatography (HPLC) and gas chromatography (GC). The levels of formaldehyde and acetaldehyde released from newly produced felt were in the ranges of 0.3~6.0 ppm and 0.2~3.0 ppm, respectively. After 14 days of aging at the room temperature, however, their levels were still in the ranges of 0.2~0.5 ppm and 0.2~0.4 ppm, respectively. By applying NCMs of 2 wt% to the automobile felt, the amount of the total volatile organic compounds (TVOCs) was reduced under the chronic inhalation minimum risk level of $0.32mmmm{\mu}g/TP$.