• 한국물환경학회지
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• 제26권6호
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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.

• 한국물환경학회지
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• 제36권3호
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• pp.194-205
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• 2020

The characteristics and behavior of dissolved organic matter (DOM) were determined by analyzing the molecular weight fractions and fluorescence properties of water samples in the downstream Nakdong River. Biogeochemical water quality parameters and fluorescent dissolved organic matter (FDOM) were analyzed at five sampling points in the downstream area of the Nakdong River January-August 2019. The molecular weight fractions of the DOM were separated by the Liquid Chromatography-Organic Carbon Detection (LC-OCD). The DOM predominantly comprised humic substances, followed by the building blocks, low molecular weight neutrals and biopolymers. The hydrophobic (aromatic) and hydrophilic properties were shown as coexisting, as most of the SUVA_254nm values were under four. The FDOM was characterized as humic-like (FDOM_H) with allochthonous origin and protein-like (FDOM_P) with autochthonous origin; the FDOM_H with autochthonous origin was also identified. The FDOM_H relies on the aromaticity of the allochthonous organic matter and increases during summer. The FDOM_H and FDOM_P, which depend on the biodegradable dissolved organic matter from phytoplankton, were highly fluorescent in winter. The allochthonous organic matter was the dominant factor contributing to the behavior of the DOM, externally introduced to the river by rainfall. The FDOM only minimally contributed to the behavior of the DOM. It can be explained as the seasonal characteristics of the DOM, varied by the source of the organic matter.

• 한국환경보건학회지
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• 제34권6호
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• pp.452-458
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• 2008

This study was undertaken to establish the biological reaction characteristics of the marine products industry wastewater which contains high concentrations of organic matter and saline. As the S/I is varied from 0.3 to 1.2, the results were follows : the observed ultimate anaerobic biodegradability varied from 72.0 to 88.0%, the first order reaction rate varied from 0.1735 to $0.3420\;day^{-1}$ and the second order reaction rate varied from 0.0132 to $0.0295\;day^{-1}$. When S/I was 0.9, the first order reaction rate had a maximum value, but the variations of the second order reaction rate were less than 1st-order reaction rate. When the operation time exceeded 2 days the gas production rapidly increased. The source of this rapid increase was due to that the activity of the granular sludge used in this study being faster than that of conventional sludge. Under aerobic condition, the characteristics of organic matter were as follows: the marine industry wastewater used in this study contained about 81% of biodegradable matter, and it was divided into readily biodegradable COD(Ss), slowly biodegradable COD(Xs), soluble COD(Si) and inert suspended COD (Xi). The percentages of each COD were 87.3%, 23.9%, 6.4% and 12.4% respectively.

• 한국토양비료학회지
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• 제48권5호
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• pp.542-548
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• 2015

This study investigated methane productions and a degradation rate of organic matters by German standard method, VDI4630 test. In this study, 4 livestock byproducts from livestock farm were selected for the investigation. The objective of this study was to estimate a distribution of organic matters by using the double first-order kinetics model in order to calculate the rate of biodegradable organic matters which degrade rapidly in the initial stage and the persistently biodegradable organic matters which degrade slowly later. As a result, all the byproducts applied in this study showed rapid decomposition in the initial stage. Then the decomposition rate began to slow down for a certain period and the rate became 5 times slower than the initial decomposition rate. This trend of decomposition rate changes is typical conditions of organic matter decompositions. The easily degradable factors ($k_1$) ranged between $0.145{\sim}0.257day^{-1}$ and persistent degradable factors ($k_2$) were $0.027{\sim}0.080day^{-1}$. Among these results, greater organic matter decomposition rates from VDI4630 had greater $k_1$ values (0.257, $0.211day^{-1}$) and smaller $k_2$ values (0.027, $0.030day^{-1}$) for dairy wastewater and forage byproduct, respectively.

• Membrane and Water Treatment
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• 제13권5호
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• pp.245-257
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• 2022

Water quality characteristics and their spatial variations in the Nakdong River were statistically analyzed by multivariate techniques including correlation analysis, CA, and FA/PCA based on water quality parameters for 17 sites over 2017-2019, yielding PI values for primary factors. Site 10 indicated the highest parameter concentrations, and results of pearson's correlation analysis suggest that non-biodegradable organic matter had been distributed on the site. Five clusters were identified in order of descending pollution levels: I (Ib > Ia) > II (IIa > IIb) > III. Spatial variations started from sub-cluster Ib in which Daegu city and Geumho-river are joined. T-P, PO4-P, SS, COD, and TOC corresponded to VF 1 and 2, which were found to be principal components with strong influence on water quality. Sub-cluster Ib was strongly influenced by NO3-N and T-N compared to other clusters. According to the PIs, water quality pollution deteriorated due to non-biodegradable organic matter, nitrogen- and phosphorus-based nutrient salts in the middle and lower reaches, illustrating worsening water pollution due to inflows of anthropogenic sources on the Geumho-river, i.e., sewage and wastewater, discharged from Site 10, at which there is a concentration of urban, agricultural, and industrial areas.

• 한국물환경학회지
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• 제39권4호
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• pp.261-268
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• 2023

The benthic macroinvertebrates index (BMI) was developed based on the 5-day biochemical oxygen demand (BOD₅), which is the amount of biodegradable organic matter in stream water. However, benthic macroinvertebrates mainly live in the streambed substrate and are affected by the interaction of water quality and substrate. This study was conducted to examine the interactive relationship between water quality items (BOD₅, total phosphorus (TP), total suspended solids (TSS)) and substrate with BMI by performing statistical analyses (four-way analysis of variance, Pearson's correlation analysis, partial correlation analysis and multiple regression analysis). The data used in the analyses were collected from 19,915 sampling units at 1,937 sites in South Korea from 2010 to 2020. The interaction effect between BOD₅ and substrate types was confirmed through a four-way analysis of variance. Partial correlation analysis and multiple regression analysis estimated the degree of influence on the change in BMI value in the order of mean grain size of the substrate as (𝜱_m) > BOD₅ > TP > TSS. BMI can be regarded as an index that evaluates the comprehensive effects of water quality and streambed status, although it is an index that was developed based on the amount of biodegradable organic matter in a water column.

• 한국물환경학회지
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• 제29권3호
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• pp.393-399
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• 2013

To control organic matters, it needs to manage not only biodegradable organic matters but also refractory organic matters. Refractory organic matters from municipal wastewater, industrial wastewater, non-point sources and etc., have been continuously discharged to the near watersheds. It is estimated that the refractory organic matter ratios are continuously increased in waterbody. In watersheds of the Total Maximum Daily Loads (TMDLs), it was investigated that COD/BOD ratios increased in many unit watersheds of the 4 major river basins. The portions COD/BOD ratios increased were found to be a 97% of Geum River unit watersheds, a 81% of Yeongsan/Seumjin River unit watersheds, a 78% of Nakdong River unit watersheds, a 70% of Han River unit watersheds, respectively. Therefore, it has become important for establishment of effective management strategies to control refractory organic matter in watersheds of the Total Maximum Daily Loads (TMDLs). In order to properly manage organic matters including refractory organic matters, the present organic indicator (BOD) has to be converted to TOC (or COD). Compared to COD and BOD, TOC, as a organic matter indicator, is evaluated more appropriate.

• 한국물환경학회지
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• 제23권1호
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• pp.19-26
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• 2007

The lab-scale BNR processes fed with Municipal Wastewater Before or After Primary Clarifier (MWBPC or MWAPC) were operated to observe the behavior of particle organic matter in terms of nitrification and denitrification efficiency. As a result of the fractionation of the COD from MWBPC or MWAPC using an aerobic respirometric serum bottle reactor, the total mass of biodegradable organic matter from MWBPC is about 52% greater than the mass from MWAPC. Batch reactors were operated to observe the effect of the Particulate Organic Matter (POM) on substrate utilization for denitrification. Although the consumption of POM for denitrification was observed, the increment of the Specific Denitrification Rate (SDNR) was not great. In terms of the effect of POM on nitrification at different HRTs, activate sludge reactors were operated to determine the optimal HRT when MWBPC and MWAPC were fed relatively. All reactors showed a great organic matter removal efficiency. Reactors fed with MWAPC had obtained the nitrification efficiency above 90% when the HRT of 4 hr, at least, was maintained, while reactors fed with MWBPC had same efficiency when the HRT longer than 5 hr was kept. Three parallel $A^2/O$ systems fed with MWBPC or MWAPC relatively were operated to investigate the effects of POM on BNR processes with varying the HRT of an anoxic reactor. For all systems, the efficiency of organic matter removal and denitrification, respectively, was great and about the same. In case of denitrification efficiency, system with MWAPC had 1.5% lower than system with MWBPC at the same HRT of anoxic reactor of 2 hr, and the increasing the HRT of the anoxic reactor by 1 hr in systems fed with MWBPC resulted in a 3.5% increment. The denitrification rate was similar while the consumption of organic matter in systems fed with MWBPC was higher than system fed with MWBPC. It suggests that POM in MWBPC was not be used significantly as a substrate for denitrification in system with the HRT of 3 hr of an anoxic reactor.

• 한국습지학회지
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• 제25권4호
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• pp.221-229
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• 2023

수도권에 일 약 8백만톤의 물을 취수하여 공급하는 팔당호는 수질보전정책 시행으로 BOD(Biochemical Oxygen Demand)1.1mg/L를 달성하였으나 난분해성 물질을 포함하는 COD(Chemical Oxygen Demand) 항목은 점점 증가하는 양상을 보였다. 난분해성 유기물질의 상수원 유입은 잠재적인 BOD의 증가, 수돗물의 냄새와 맛 유발, THM(Trihalomethane) 발생 증가, 조류 증식을 일으키며 유해 난분해성 미량오염물질이 잔류할 경우 수생 환경에서 내분비 교란과 항생제 내성과 같은 현상을 유발한다. 본 연구에서는 팔당호의 난분해성 유기물질 관리를 위해 팔당호와 팔당호 상류의 점 오염원과 비점오염원의 난분해성 유기물질 유출 농도를 파악하기 위한 모니터링을 실시하였다. 지역별 난분해성 유기물질 유출 농도를 비교하고 하수처리장에서의 제거율을 파악하였다. 또한 피어슨 상관성 분석 기법을 사용해 유기물질 지표와 선행건기일수, 선·선행건기일수간 상관성 분석을 실시하였다. 하천과 팔당호의 난분해성 유기물질 농도는 유사한 양상을 보였다. 하수처리장 유출수는 하천과 팔당호보다는 높은 농도를 보였으며, 유입수와 유출수 농도의 비교 결과 하수처리장에서 난분해성 유기물질 제거율은 65.73%였다. 난분해성 유기물질 유출 농도와 선행건기일수, 선·선행건기일수 사이에서는 유의미한 상관성이 나타나지 않았다. 이는 데이터 부족으로 판단되며 장기적인 모니터링으로 데이터 축적이 필요하다 사료된다.