• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.969-975
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• 2010

Estimating the organic matter loadings from individual treated sewage has become important for establishment of effective management strategies to control refractory organic matter (R-OM) in watersheds. For this study, regression equations were constructed using treated sewage data to convert the chemical oxygen demand (COD) concentrations, which are mostly available from open database, into total organic carbon (TOC) and R-OM concentrations. Effluent samples were collected from five major sewage treatment plants (STPs) located upstream of the lake Paldang. Variations in the OM concentrations were not associated with either the location of the STP or the sampling season. The effluent investigated were characterized by higher ratio of R-OM with respect to biodegradable organic matter (B-OM) and higher presence of dissolved organic matters (DOM) versus particulate organic matter (POM). Compared to $COD_{Mn}$, $COD_{Cr}$ exhibited higher oxidation efficiencies and greater variations in the concentrations. The concentrations of $COD_{Mn}$ were positively correlated with dissolved organic carbon (DOC), total organic carbon (TOC), and R-OM concentrations. There was nearly no seasonal and annual variation in the regression equations between $COD_{Mn}$ and TOC or R-OM concentrations. The constructed regression equations for TOC and R-OM were $0.650({\pm}0.071){\times}COD_{Mn}+1.426({\pm}0.575)$ and $0.340({\pm}0.083){\times}COD_{Mn}+2.054({\pm}0.670)$, respectively. The established equations are expected to contribute to estimating OM loadings from the STPs into the lake Paldang and also to compensating for the deficiency of the data for effluent OM concentrations in STP.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.173-181
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• 1993

Seasonal distributions of nutrients and particulate organic matter were investigated in Asan Bay, Korea. Most of nutrients were high in August and low in February. The atomic ratios of inorganic nitrogen to phosphorous were close to Redfield ratio except in May when the ratio was 24.8. In May, nutrient concentrations except phosphorous decreased with salinity until $31.5{\sim}32.0%0$, but the concentrations increased again with salinity, impling that there were nutrient input sources within the estuary. Howerer, significant inverse relationships between nutrients and salinity in August suggest that nutrient sources were river discharge. Maximum chlorophyll a concentrations occurred in May. Relatively low ratios of $R_b$ to $R_a$($R_b$: fluorescence before acidification; $R_a$: fluorescence after acidification) during the study periods indicate that phytoplankton were not in good physiological condition. Relatively low ratio of particulate biogenic silica(PBSi) to particulate organic carbon(POC) and high ratios of PBSi and POC to chlorophyll a during the study periods suggest input of non-living detrital PBSi and POC from bottom in Asan Bay, where strong tidal mixing occurs.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.713-721
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• 2013

This study is about emission characteristics of HAPs and particulate matters emitted by spray of paint and organic solvent usually used in vehicle paint facilities. To analyze emission characteristics of HAPs and particulate matters emitted from vehicle paint facilities are calculated based on the measuring emission quantity of pollutants based on the amount of paint used (kg) and unit area ($m^2$) by paint manufacturers (J company, K company, and R company). In cases of paint manufacturers (J, K, and R), average emission factors of VOCs, carbonyl compound, particulate matter, and PAHs per 1 kg of paint were 327.81 g/kg, 5.98 g/kg, 336.70 g/kg, and 0.0078 g/kg respectively. The average emission factors of VOCs, carbonyl compounds, particulate matters, and PAHs by unit area were $171.55g/m^2$, $3.10g/m^2$, $176.27g/m^2$, and $0.0036g/m^2$ respectively.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.98-104
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• 2010

An experimental investigation was conducted to analyze the effects of EGR ratio on the combustion, exhaust emissions characteristics and size distributions of particulate matter in a single cylinder diesel engine with common-rail injection system fueled with biodiesel derived from soybean. In order to analyze the combustion, exhaust emissions and measurement of size distributions of particulate matter were carried out under various EGR ratio which was varied from 20~60% and the results were compared to those of results without EGR. The experimental results show that ignition delay was extended and maximum value of rate of heat release (ROHR) was decreased according to increasing of EGR ratio. In addition, oxidies of nitrogen ($NO_x$) emissions were reduced but soot emissions were increased under increasing of EGR ratio. However, under higher EGR ratio region, soot was slightly decreased. And then the particulate size distribution shows that high exhaust gas temperature restrain the formation of soluble organic fraction (SOF) which were beyond the accumulation mode (100~300nm) and lead to increase of nuclei mode particles.

• Journal of Korean Society on Water Environment
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• v.27 no.3
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• pp.306-313
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• 2011

In this paper, runoff characteristics of South-Han river watershed in terms of refractory organic matters were investigated. The concentrations of DOC, POC, R-DOC, R-POC in runoff and flow rates were determined by monitoring 27 times in dry season and 4 times in rainy season. The concentrations of the dissolved refractory organic matter, R-DOC was the lowest in fall and similar in the other dry seasons. The particulate refractory organic matter, R-POC showed less fluctuation than R-DOC. In summer, mass loading was the highest than other dry seasons. The concentrations of R-DOC, R-POC were showed to be affected by runoff volume. The mass loading grows higher as runoff volume gets higher.

• Journal of Korean Society on Water Environment
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• v.33 no.5
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• pp.580-586
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• 2017

The fractionation characteristics of organic matter were investigated in inflow and effluent of each other pollution sources and river. While the DOC/TOC ratio in the influent of public sewage treatment plant and livestock disposal facilities was above 0.58, the POC/TOC ratio of human livestock Night soil treatment plant and stormwater runoff was more than 0.7. The TOC removal efficiency of public sewage treatment plant and human livestock Night soil treatment plant were 88.5 % and 99.6 %, respectively. Although the concentration distribution of organic matter pollution most of total organic carbon (TOC) in effluent of pollution sources accounted for dissolved organic carbon (DOC) type (DOC/TOC ratio >0.89) and Refractory-DOC (RDOC)/TOC ratio was higher (>0.65). The fractionation characteristics of organic matter in river were similar with that of sewage treatment plant and TOC concentration showed the positive correlation with DOC ($r^2=0.93$) and RDOC ($r^2=0.89$) concentration. The decay rate of Labile DOC (LDOC) (avg. $0.128day^{-1}$) was higher than labile particulate organic carbon (LPOC) ($0.082day^{-1}$), while that of DOC ($0.008day^{-1}$) was lower than POC ($0.039day^{-1}$) (paired t-test, p < 0.001, n = 5). These study results suggested that it should consider important both TOC and DOC as the target indicator to control refractory organic matter in pollution sources.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.138-142
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• 1998

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now being studied actively. In this study, an experiment was conducted to analyze the effects of low sulfur diesel fuel in heavy duty diesel engine equipped with DOC. We tested to estimate change of engine performance for the low and high sulfur diesel fuels in a 11,000cc diesel engine equipped with DOC. We conducted test to estimate the reduction efficiency of exhaust gas in D-13 mode of heavy duty diesel regulation mode and in smoke opacity mode for two samples of high sulfur content (0.2%) and low sulfur content(0.05%)

• Korean Journal of Ecology and Environment
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• v.47 no.2
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• pp.127-134
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• 2014

Organic carbon and nitrogen stable isotope ratios of particulate organic matter (POM) were determined at 7 stations (6 stations in Han river and Paldang dam outflow station) from May to October 2013, in order to understand the origin of POM at the Han river. ${\delta}^{13}C$ values of POM in four stations showed significant seasonal changes season, but ${\delta}^{15}N$ values were enriched in around Kyeongan stream (K). POC, PN and Chl-a concentration showed a similar seasonal pattern in Kyeongan stream, with an apparent decrease from July to August. POC and PN concentration has a higher correlation with Chl-a concentration in Kyeongan stream (K). ${\delta}^{13}C$ and ${\delta}^{15}N$ values of POM has a lighter value during lower Chl-a concentration peroid, compared to other seasons. Our results revealed that Kyeongan stream (K) seemed to be influenced by substantial amount of organic manure or fertilizer input in 2013, compared to the previous year (2012). These results suggest that the analysis of stable isotope ratios is a simple but useful tool for the identification of organic matter origin in aquatic environments.

• Journal of Sensor Science and Technology
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• v.32 no.3
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• pp.147-153
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• 2023

Metal-organic frameworks (MOFs) of cobalt gallate were synthesized and deposited on gold electrodes using self-assembly monolayers (SAMs) and hydrothermal processing. These MOF films exhibit strong adsorption capabilities for gaseous particulates, and the use of SAMs allows the synthesis and deposition processes to be completed in a single step. When cobalt gallate is mixed with SAMs, a coordination bond is formed between the cobalt ion and the carboxylate or hydroxyl groups of the SAMs, particularly under hydrothermal conditions. Additionally, the quartz crystal microbalance (QCM) gas sensor accurately measures the number of particulates adsorbed on the MOF films in real-time. Thus, the QCM gas sensor is a valuable tool for quantitatively measuring gases, such as SO₂, NO₂, and CO₂. Furthermore, the QCM MOF film gas sensor was more effective for gas adsorption than the MOF particles alone and allowed the accurate modeling of gas adsorption. Moreover, the QCM MOF films accurately detect the adsorption-desorption mechanisms of SO₂ and NO₂, which exist as gaseous particulate matter, at specific gas concentrations.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.401-410
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• 2017

This study analyzed the changes in the concentrations of organic matters in constructed treatment wetlands, coming from discharge water from a sewage treatment plant and non-point pollutant sources during rainfall events. At the beginning of a rainfall event, a massive amount of particulate organic matter flowed in, and was removed from the sedimentation basin (S1, S2); dissolved organic matter was removed after passing through stepwise treatment processes in the wetland. During dry period in the wetland, the removal efficiency rate for COD and TOC was -21 and -7%, respectively; during the rainfall event, the removal efficiency rate for COD and TOC were 47 and 43%, respectively. The highly-concentrated organic matters that flowd in at the beginning of the rainfall event was stabilized by various structures in the wetland before water discharge. Cyanobacteria blooms annually at the confluence of the So-ok stream and Daecheong Lake. Therefore, it is expected that the wetland will contribute significantly to reducing cyanobacteria and improving water quality in the area.