• 공업화학
• /
• 제23권5호
• /
• pp.490-495
• /
• 2012

오존/활성탄 공정을 이용하여 페놀을 처리 할 경우, 활성탄에 의해 나타나는 촉매효과에 관한 연구를 수행하였다. 오존 단독공정에 활성탄을 추가할 경우, 활성탄 투입량이 증가할수록 용존 오존 및 페놀의 분해효율이 증가하는 것으로 나타났다. 이는 활성탄에 의해서 용존 오존이 분해되어 생성된 수산화 라디칼이 페놀 제거에 영향을 미쳤으며, 본 연구에서는 활성탄의 촉매효과([$\Delta$phenol] / $[{\Delta}O_{3}]_{AC}$)로 나타내었다. 활성탄 10~40 g/L 투입 시, 모든 활성탄의 최대 촉매효과 값은 $2.0\;{\pm}\;0.1$로 나타났지만, 10 g/L와 20 g/L를 투입한 경우, 40 min 경과 후 최대 촉매효과에 근접한 반면, 활성탄 30 g/L와 40 g/L를 투입한 경우, 반응 20 min 경과 후 최대 촉매효과에 도달하였다. 또한 Total Organic Carbon (TOC, 총유기탄소)의 제거율은 오존 단독공정에서 0.23으로 나타났으며, 오존/활성탄 공정에서는 0.63으로 나타났다.

• 한국물환경학회지
• /
• 제36권4호
• /
• pp.284-299
• /
• 2020

Dam reservoirs play a particularly crucial role in processing the allochthonous and the autochthonous dissolved (DOC) and the particulate (POC) organic carbon and in the budget of global carbon cycle. However, the complex physical and biogeochemical processes make it difficult to capture the temporal and spatial dynamics of the DOC and the POC in reservoirs. The purpose of this study was to simulate the dynamics of the DOC and the POC in Daecheong Reservoir using the 3-D hydrodynamics and water quality model (AEM3D), and to quantify the mass balance through the source and sink fluxes analysis. The AEM3D model was calibrated using field data collected in 2017 and showed reasonable performance in the water temperature and the water quality simulations. The results showed that the allochthonous and autochthonous proportions of the annual total organic carbon (TOC) loads in the reservoir were 55.5% and 44.5%, respectively. In season, the allochthonous loading was the highest (72.7%) in summer, while in autumn, the autochthonous loading was the majority (77.1%) because of the basal metabolism of the phytoplankton. The amount of the DOC discharged to downstream of the dam was similar to the allochthonous load into the reservoir. However, the POC was removed by approximately 96.6% in the reservoir mainly by the sedimentation. The POC sedimentation flux was 36.21 g-C/㎡/yr. In terms of space, the contribution rate of the autochthonous organic carbon loading was high in order of the riverine zone, the transitional zone, and the lacustrine zone. The results of the study provide important information on the TOC management in the watersheds with extensive stagnant water, such as dam reservoirs and weir pools.

• 산업기술연구
• /
• 제17권
• /
• pp.297-303
• /
• 1997

This study investigates the characteristics of humic acid before and after ozonation. The results were comapred in such terms as CODCr, CODMn, TOC(total organic carbon) and molecular size distribution. As a result of ozonation (with the dose of 3mgO3/mgHumic Acid), UV NIS absorbance, CODCr, CODMn and TOC were decreased with similar tendency. The mole fraction of high molecular size was rapidly decreased and the fraction ratio of low molecular size was increased through ozone treatment. This fact can be correlated with the change in the difference and the ratio of CODCr and CODMn (the value of CODCr-CODMn and CODMn/CODCr). From this result, it can be inferred that the molecular size and the degree of chemical oxidative degradation of humic acid after ozonation were changed.

• 한국분말재료학회지
• /
• 제10권2호
• /
• pp.136-141
• /
• 2003

In the present study, $TiO_2$ imbedded copper matrix powders have been successfully prepared from the ($CuSO_4+TiO_2+Zn$) composite salt solution. The composite $Cu/TiO_2$ powders were formed by drying the solution at $200{\sim}~400^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting TOC (total organic carbon) amount with TOC analyzer (model 5000A Shimadzu Co). Phase analysis of $Cu/TiO_2$ composite powders was carried out by XRD, DSC and powder size was measured with TEM. The mean particle size of composite powders was about 100 nm and a few zinc and copper oxide phases was included. The reduction ratio of TOC amount was 60% by the composite $Cu/TiO_2$ powders under the UV irradiation for 8 hours.

• 한국물환경학회지
• /
• 제22권5호
• /
• pp.831-837
• /
• 2006

The present study applies wavelet transform for the extraction of various periodicities which are included in TOC and pH time series of water quality and rainfall data. The primary objective of the present study is to detect the relationships between the respective data through the correlation analysis using the approximation components which are decomposed by wavelet transform. The results reveal the approximation components of TOC and pH in the 5th level of wavelet transform can explain more than 99% of the whole energy for the raw data respectively and there are considerably high correlation between the approximation components of the respective data used for the study even through no significant correlation between the raw data has been detected.

• 열처리공학회지
• /
• 제35권6호
• /
• pp.337-342
• /
• 2022

In metal cutting, water-soluble cutting oil is used for cooling the surface of the workpiece and improving the surface roughness. However, waste cutting oil contains preservatives and surfactants, and if it is discarded as it is, it has an great influence on environmental pollution. For this reason, regulations on the use of cutting oil are being stricter. Hence, the development of eco-friendly treatment technologies is required. In this study, a diamond electrode doped with boron on a niobium substrate was deposited by thermal filament chemical vapor deposition and waste cutting oil was treated using an electrochemical method. Compared to the total amount of organic carbon contained in the waste cutting oil, it was confirmed that the boron-doped diamonds developed from this study showed much better performance than electrodes that has been widely used before.

• 자원환경지질
• /
• 제35권2호
• /
• pp.171-177
• /
• 2002

제4기 후기의 층서와 퇴적환경 변화를 조사하기 위하여 울릉분지 남서부 해역에서 채취한 푸 개의 피스톤 코어 시료를 분석하였다. 코어는 이질 퇴적물이 주종을 이루었고 일부 사질 퇴적물 및 테프라층(tephra layer)으로 구성되어 있다. 이미 확인된 울릉분지의 테프라층을 이용하여 층서 대비를 한 결과, 코어는 약 46,100년의 층서 기록을 보이며, 마지막빙기 동안의 퇴적률(12.1~14.9 cm/kyr)은 대양보다 높은 편이었다. 동위원소층서 2 동안 퇴적된 시료구간에서는 저탁류의 영향을 받은 몇 종류의 퇴적상이 교호하여 나타난다. 코어 00GHP-07의 하부구간에서는 가스 방출에 의하여 형성된 것으로 보이는 수평균열 구조가 관찰된다. 시료의 총유기탄소(TOC) 함량은 전체적으로 매우 높다(평균1.8%). 특히 총유기탄소의 값은 Termination I 동안 증가하는 추세를 보이는데, 이것은 이 기긴 동안 남서부 울릉분지가 산소가 다소 결핍한 환경으로 전이하였음을 의미한다.

• 멤브레인
• /
• 제31권6호
• /
• pp.426-433
• /
• 2021

본 연구에서는 polyketone (PK)을 이용하여 전기방사 조건에 따른 섬유 형상의 특성 변화와 유수분리 가능성을 확인해 보았다. 고습과 저습 조건에서는 마이크론 직경의 섬유가 형성되었으며, 특히 고습에서는 섬유의 표면이 거칠게 변한 것이 확인되었다. 섬유 직경을 micro에서 nano로 변경하기 위하여 방사용액에 염을 추가하였으며, 그 결과 섬유 직경이 약 90% 감소하는 것을 확인할 수 있었다. 제조된 rPK-LNC와 PK-H로 유수분리 특성을 확인하기 위해 oil/water 에멀션으로 중력 조건에서 유수분리를 진행하였으며 total organic carbon (TOC)와 탁도를 측정하여 특성을 분석하였다. 제거율 확인결과 탁도가 TOC와 동일한 경향성을 나타내는 것이 확인되었다. 따라서 본 연구에서는 고분자의 방사조건과 염의 유무에 따른 분리막의 섬유 형상과 물리적 특성변화와 이를 이용한 유수분리 특성에 대해 연구하였다.

• 환경영향평가
• /
• 제8권1호
• /
• pp.81-92
• /
• 1999

This study discussed the appropriateness of organic matter indexes such as biochemical oxygen demand(BOD) and chemical oxygen demand with potassium permanganate($COD_{Mn}$) in water quality environmental standard of streams and lakes and the applicability of the items to water quality environmental standard to add or substitute COD with potassium dichromate ($COD_{Cr}$) and total organic carbon(TOC) being used as index of organic matter. And indexes of organic matter content and organic carbon concentration were distinguished between dissolved and particulate component in water sample to estimate their effect on pollutants loading in lake and stream. The ratio of $COD_{Cr}$/BOD was 5.1 under BOD concentration 3mg/L in river water quality environmental standard II, and 2.67 above it. This ratio was diminished to 2.04 when BOD concentration was more than 8mg/L, in river quality environmental standard IV. Also the ratio of $COD_{Mn}$/BOD showed 2.16 under 3mg/L(BOD), and 1.1 above it. This ratio is also diminished to 0.84 over 8mg/L(BOD). Accordingly, we should apply this ratio depending on the concentration level to add and change organic matter index of water quality environmental standard newly. The ratio $COD_{Cr}/COD_{Mn}$ both in lake and stream shows 2.37(r=0.986, p<0.001). But the ratios showed range of 2.34~2.50, which is no much difference of this ratio according to $COD_{Mn}$ concentration.

• 한국물환경학회지
• /
• 제25권4호
• /
• pp.560-567
• /
• 2009

Treated or untreated wastewater may be a major source of refractory organic matters (R-OM) in drinking water sources. For this study, spectroscopic characteristics of wastewater OM were investigated using the samples from 20 wastewater treatment plants, which are located at the upstream of the lake Paldang, to suggest a estimate index for R-OM in wastewater. R-OM was quantified by measuring total organic carbon (TOC) concentration of the wastewater samples remaining after 28-day dark incubation. Among the traditional OM indices such as chemical oxygen demand (COD) and initial TOC, CODMn showed the lowest correlation coefficients with R-TOC of the samples. The ratios of carbonaceous biochemical oxygen demand (CBOD) to $COD_{Cr}$ had a better correlation with the percent distribution of R-OM than $BOD/COD_{Cr}$ ratios. terrestrial humic-like fluorescence (THLF) exhibited the highest correlation coefficient with R-TOC among the indices obtained from the synchronous fluorescence spectra of the samples. Milori index, one of the humification indices, showed a good correlation with the percent distribution of wastewater. This study demonstrated that fluorescence properties might be a better indices to estimate the concentrations and the distributions of wastewater OM compared to the specific UV absorbance (SUVA) values. Some useful formulas based on OM spectroscopic characteristics were finally suggested to predict R-OM in wastewater.