• Environmental Engineering Research
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• 제15권1호
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• pp.9-14
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• 2010

The objective of this study was to assess the variation in the concentration of assimilable organic carbon (AOC) in a drinking water resource, and investigate the characteristics of AOC derived from algae. The seasonal change in AOC at the Kamafusa dam corresponded to changes in the algal cell number. In order to understand the relationship between AOC and algae in a water resource and water purification plant, two kinds of laboratory experiment were performed. The algal culture experiment showed that extracellular organic matter (EOM) that was released during the growth of Phormidium tenue with M-11 medium led to significant increases in the AOC concentration, but no significant variation in the AOC concentration was observed with CT medium containing a high dissolved organic carbon concentration. The chlorination experiment showed that the AOC included in EOM was not easily removed by chlorination, although the AOC included in intercellular organic matter released from the algal cells by chlorination was removed under conditions where residual chlorine was detected.

• 한국환경과학회지
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• 제10권5호
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• pp.315-321
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• 2001

This study was conducted to estimate the decomposition capacity for organic matter by microbe of tidal flat sediments (Hajae, Dongjin and Mankyung). The decomposition rate constants (K') have been determined by Thomas slope method and compared with the values of each tidal flats. The decomposition rates of organic matter by microbe were initially very slow, but at the end of 12 hours, very sharply increased. The values of decomposition rate constant for Dongjin, Mankyung and Hajae tidal flat sediment were 1.364$day^{-1}$/, 1.080d$day^{-1}$ and 0.735$day^{-1}$, respectively. The decomposition rate constant of Dongjin tidal flat sediment which affected by livestock wastewater was higher than others. The decomposition quantity (mg/g/day) of organic matter by microbe of tidal flat sediments was 0.4mg/g/day for Dongjin, 0.36mg/g/day for Mankyung and 0.36mg/g/day for Hajae. The average of decomposition quantity was 0.37mg/g/day. To calculate purification capacity (kg/ha) of organic matter by microbe, we applied to two assumption ; 1) biological action by microbe is occur within 0.1cm under surface 2) specific gravity of sediment are 2.5g/$\textrm{cm}^2$. The purification capacity of organic matter by microbe of tidal flat sediment was calculated to 9.25kg/ha. The relationships between decomposition rate constant (K') and ignition loss (I. L), chemical oxygen demand by sediment (CO $D_{sed}$), total carbon(TC), silt and clay as index of organic matter were a high positive($R^2$=0.97~1.00).

• 한국토양비료학회지
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• 제49권6호
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• pp.783-788
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• 2016

Agricultural management of paddy soil depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 paddy soils in Gyeongnam Province by fatty acid methyl ester (FAME). The average of microbial communities in paddy soils were 32.2% of total bacteria, 16.7% of Gram-negative bacteria, 12.9% of Gram-positive bacteria, 2.0% of actinomycetes, 14.9% of fungi, and 1.3% of arbuscular mycorrhizal fungi. The communities of total bacteria (34.9%) and Gram-negative bacteria (19.4%) in soils with $30{\sim}35g\;kg^{-1}$ of organic matter were significantly larger than those in soils with other organic matter levels. However, soils with $20{\sim}30g\;kg^{-1}$ of organic matter had significantly low ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ as compared with soils with $30{\sim}35g\;kg^{-1}$ of organic matter, indicating microbial stress decreased (p < 0.05). In principal component analyses of soil microbial communities, Gram-negative bacteria should be considered as a potential responsible factor for the obvious microbial community differentiation that was observed between the two different organic matter levels in paddy fields. Thus, soils containing $20{\sim}30g\;kg^{-1}$ of organic matter were responsible for strong effect on microbial biomass and stress in paddy fields.

• 한국토양비료학회지
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• 제31권4호
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• pp.380-383
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• 1998

본 연구는 퇴비중의 유기물 함량으로부터 탄소함량을 구하기 위한 환산계수를 결정하기 위하여 수행하였다. 퇴비중의 유기물 함량은 회화법으로, 탄소함량은 원소 분석기를 사용하여 분석한 결과 유기물 함량과 탄소함량의 관계는 "탄소함량(%)=$1.995+0.484{\times}$유기물 함량(%)"의 직선 회귀식을 따랐고, 분산분석에 의한 회귀직선의 유의성 검정은 고도로 유의하게 나타났다(P < 0.001). 기존의 토양 유기물 환산계수 1.724나 1.8을 적용할 경우, 퇴비중의 유기물 함량으로부터 환산한 탄소함량은 실제보다 10% 이상 높게 평가되어 우리 나라에서 생산, 판매되는 퇴비의 탄소함량을 구할 때는 상기 회귀식을 적용하는 것이 타당하리라 생각된다.

• 한국토양비료학회지
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• 제48권6호
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• pp.648-657
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• 2015

Soil organic matter (SOM) plays an important role in the continuous production and environmental conservation in arable soils. In particular, the decomposition of organic matter in soil might promote soil organic matter and fertility due to the mineralization of N. In this study, to evaluate the effect of organic matter amendment on the C mineralization and N dynamic, $CO_2-C$ flux, extractable N and $N_2O$ emission were determined using closed chamber for 4 weeks at 10, 15, $20^{\circ}C$ of incubation temperature after the mixture of $2Mgha^{-1}$ rice straw compost and rye in sandy loam and clay loam. Regardless of soil texture, decomposition rates of rice straw compost and rye at $10{\sim}20^{\circ}C$ of incubation temperature ranged from 0.9 to 3.8% and 8.8 to 20.3%, respectively. Rye application in soil increased $NH_4-N$ and $NO_3-N$ content as well as the $N_2O$ emission compared to the rice straw compost. After incubation for 4 weeks, total C content in two soils was higher in rice straw compost than in rye application. In conclusion, application of rice straw compost and rye to soil was able to improve the soil organic matter and fertility. However, organic matter including the recalcitrant compounds like rice straw compost would be effective on the management of soil organic matter and the reduction of greenhouse gases in soil.

• 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.

• 한국물환경학회지
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• 제38권3호
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• pp.133-142
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• 2022

Natural organic matter (NOM) is a heterogeneous mixture of organic matter with various polarities and molecular weights in an aquatic environment. This study investigated the effects of separation conditions (resin volume, organic matter, etc.) and the repeated use of the resin for the fractionation of organic components in the DAX resin fractionation method. The distribution characteristics of the organic components ((hydrophilic [Hi], hydrophobic acid [HoA], and hydrophobic neutral [HoN]) under the derived fractionation conditions were also analyzed. Constant fractionation results (i.e. HoA/Hi ratio) were obtained in the column capacity factor (i.e. the packed resin volume) in the range of 50 to 100. The resin-packed column maintained constant separation efficiency for up to two repeated uses. The above conditions were applied to wastewater and stream water samples (before and after rainfall). The results showed that the concentration of organic matter in the wastewater effluent was 2-15 times lower with an increased ratio of hydrophilicity to hydrophobicity (i.e. Ho/Hi) compared to the influent depending on the industrial wastewater classification. Particularly, HoN was found to have a high content distribution, 10.2-50.4% of the total dissolved organic matter (DOM), in the effluents. For the stream water, the content of Hi or HoN increased significantly after rainfall, suggesting a correlation with the distribution characteristics of pollutants from the stream watershed. The results provide useful data to enhance the reliability of the DAX resin fractionation and its application to environmental samples.

• 유기물자원화
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• 제24권4호
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• pp.69-76
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• 2016

최적의 유기농경지 토양 관리 기준 및 양분 관리 방안을 제시하기 위한 기초자료를 만들기 위해 유기농 인증을 받은 국내 75개 선도 농가를 선정하고, 논 토양에서 이앙 전에 토양 시료를 채취하여 이화학적 특성을 분석하였다. 유기농 토양은 평균적으로 pH 6.2, 유기물 $25.6mg\;kg^{-1}$, 유효 인산 $88.4mg\;kg^{-1}$이나 편차가 크게 나타났으며, 유기농과 관행농을 포함한 전국 규모 토양조사 결과에 비해 pH는 높게 나타났고, 유효 인산은 낮게 나타났으며 유기물은 비슷한 수준을 보였다. 한편 재배년수에 따라 토양 pH와 공극률은 높아지고 있었으며, EC와 유효인산, 용적밀도, 토양 경도는 낮아지고 있었으며, 유기물은 차이를 보이지 않았다. 용적밀도는 표토($R^2=-0.5424$)와 심토($R^2=-0.6429$) 모두 유기물과 부의 상관관계를 나타냈다(p<0.05). 조사 결과 유기물과 유효 인산을 제외한 대부분의 토양 이화학성 인자들에서 토양의 질이 향상되고 있어, 향후 유기물 관리 대책 수립과 유기농업자재로 사용가능한 인산 자재의 발굴이나 개발이 필요한 것으로 사료되었다.

• 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.