• 한국해양공학회지
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• 제11권3호
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• pp.132-143
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• 1997

Removal of spilled oil over the sea and the river has become one of the urgent problem in these days. Removing oil using mechanical devices are recommended because chemical dispersion can cause the secondary contamination in the environment. In the present study a series of experiments were carried out to study the effect of working conditions of a belt type skimmer on the rate of recovery for the spilled oil. The oil chosen for the present experiment was diesel oil. Three different situations, namely, upward, downward, up-and-downward pickup have been investigated for various contact angles, belt speeds and oil thicknesses. The results show that the rate of oil recovery for the case of downward pickup with a contact angle of 45.deg. shows the highest among all the conditions. For the removal of spilled diesel oil the optimal belt speed can be found as the critical value to reach the saturated pickup rate for a given oil thickness. The recovery rate of bunker C oil shows 4-6 times higher than that for diesel oil. And the optimal belt speed for bunker C oil can be found less than that for diesel oil for the same slick thickness.

• 한국염색가공학회지
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• 제11권6호
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• pp.24-35
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• 1999

This study was carried out to investigate the changes of surface characteristics of polyester fabrics on the deposition and the removal of oily soils from polyester fabrics in detergency, The relations between the removal of soil and the changes of surface properties of polyester fabrics treated with water- and oil-repellent agents were discussed before and after various wash cycles. Two kinds of fluoropolymers were selected as water-and oil-repellent finishing agents. The effects of water- and oil-repellent finishes were determined by the water repellency and oil repellency. The surface properties of untreated and treated polyester fabrics were evaluated with respect to contact angle and wicking time. The treatment of polyester fabrics with fluoropolymers improved efficiently water repellency, oil repellency, contact angle and wicking time. But those properties were greatly decreased after 3 times of wash cycles in detergency The deposition of oily soils on the untreated fabrics was drastically increased with increasing of wash cycles. The deposition and the removal of oily soils from fabrics treated with fluoropolymer having hydrophobic components were very low after various wash cycles. The deposition and the removal of oily soils on the fabrics treated with fluoropolymer having hydrophilic components were high comparatively after various wash cycles. Even though the surface properties of treated fabrics were greatly decreased with the increasing of wash cycles, the remains of oily soils on the fabrics were lower than those of untreated fabrics in various wash cycles. But the remains of soils were drastically increased after 10 times of wash cycles in any cases.

• 한국미생물·생명공학회지
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• 제18권1호
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• pp.31-34
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• 1990

중온성과 고온성인 황산염 환원세균들을 사용하여 dibenzothiophene, 원유 및 Bunker C 유의 탈황실험을 하여 중온성인 분리균주 Desulfovibrio desulfuricans M6는 dibenzothiophene, crude oil를 42, 17 까지 탈황시켰으며, 고온성은 Desulfovibrio thermophilus에서 dibenzothiphene Bunker C 유를 각각 68, 33 탈화시켜, 황산염 환원세균에 의한 석유의 탈황 가능성을 보였다. 또한 Desulfovibrio 속과 Desulfotomaculum 속의 탈황 능력의 차이로부터 탈황기작이 hydrogenase와 환원력 원인 수소가 관련이 있다는 것을 알았다.

• Environmental Engineering Research
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• 제19권2호
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• pp.151-155
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• 2014

This study compares the effects of flow on oil and suspended solids removal efficiencies in circular enhanced gravity plate separator equipped with coalescence medium. Coalescence medium acts to capture rising oil droplets and settling solid particles and assist in the coalescence of oil and coagulation of solid. The circular separator uses an upflow center-feed perforated-pipe distributor as the inlet. The co-current flow is achieved using 4 increasing sizes of frustum, whereas cross flow uses inclined coalescence plates running along the radius of the separator. The different arrangement gave the cross flow separator a higher coalescence plan area per operational volume, minimal and constant travelling distance for the oil droplets and particles, lower retention time, and higher operational flowrate. The cross flow separator exhibited 6.04% and 13.16% higher oil and total suspended solids removal efficiencies as compared to co-current flow.

• 신재생에너지
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• 제19권4호
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• pp.27-34
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• 2023

In this study, microalgal oil was extracted from Nannochloropsis oceanica cultured in an open raceway pond and converted into biodiesel using a solid acid catalyst. Microalgal oil was extracted from two types of microalgae with and without nitrogen starvation using the KOH-solvent extraction method and the fatty acid content and oil extraction yield from each microalgae were compared. The fatty acid content of N. oceanica was 184.8 mg/g cell under basic conditions, and the oil content increased to 340.1 mg/g under nitrogen starvation conditions. Oil extraction yields were 90.8 and 95.4% in the first extraction, and increased to 97.5 and 98.8% after the second extraction. Microalgal oil extracted by KOH-solvent extraction was yellow in color and had reduced viscosity due to chlorophyll removal. In biodiesel conversion using the catalyst SO₄^2-/HZSM-5, solvent-extracted oil showed a FAME content of 4.8%, while KOH-solvent-extracted oil showed a FAME content of 90.4%. Solid acid catalyst application has been made easier by removal of chlorophyll from microalgal oil. The FAME content increased to 96.6% upon distillation, and the oxidation stability increased to 11.07 h with addition of rapeseed biodiesel and 1,000 ppm butylated hydroxyanisole.

• 상하수도학회지
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• 제25권6호
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• pp.971-979
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• 2011

Palm Oil Mill Effluent (POME) is the mixed organic wastewater generated from palm oil industry. In this study, kinetic analysis with treating POME in an anaerobic hybrid reactor (AHR) was performed. Therefore, the AHR was monitored for its performances with respect to the changes of COD concentrations and hydraulic retention time (HRT). Batch tests were performed to find out the substrate removal kinetics by granular sludge from POME. Modified Stover Kincannon, First-order, Monod, Grau second-order kinetic models were used to analyze the performance of reactor. The results from the batch test indicate that the substrate removal kinetics of granular sludge is corresponds to follow Monod's theory. However, Grau second-order model were the most appropriate models for the continuous test in the AHR. The second order kinetic constant, saturation value constant, maximum substrate removal rate, and first-order kinetic constant were 2.60/day, 41.905 g/L-day, 39.683 g/L-day, and 1.25/day respectively. And the most appropriate model was Grau second-order kinetic model comparing the model prediction values and measured COD concentrations of effluent, whereas modified Stover-Kincannon model showed the lowest correlation.

• 한국환경과학회지
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• 제20권11호
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• pp.1499-1507
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• 2011

Practical disposal of transformer insulation oil laden with PCBs (polychlorinated biphenyls) by a chemical treatment has been studied in field work. The transformer insulation oil containing PCBs was treated by the required amounts of PEG (polyethylene glycol) and KOH, along with different reaction conditions such as temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. Removal efficiencies of PCBs in insulation oil before and after chemical treatment were examined. The removal efficiency of PCBs was very low at lower temperatures of 25 and $50^{\circ}C$. Under the reaction condition of PEG 600/KOH/$100^{\circ}C$/2hr, removal efficiency of PCBs was approximately 70%, showing completely removal of PCBs containing 7~9 chlorines on biphenyl frame which appear later than PCB IUPAC Number 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to $150^{\circ}C$ and 4 hours, removal efficiency of PCBs reached 99.99% without any formation of PCDDS/PCDFs during the process. Such reaction conditions were verified by several official analytical institutions. In studying the reaction of PEG with PCBs, it confirmed that the process of chemical treatment led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines.

• KSBB Journal
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• 제24권1호
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• pp.53-58
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• 2009

본 연구는 인위적으로 오염시킨 사질토와 미세토를 대상으로 미생물, 영양제 및 계면활성제를 이용하여 성능실험을 수행하여 시간에 따른 TPH와 BTEX의 제거 특성 등에 대해 알아보았다. 수분 함량을 10${\sim}$20%로 유지하면서 실험한 결과, 사질토를 이용한 TPH 제거율은 C군의 경우 C-1 (미생물+ 영양제), C-2 (미생물 + 영양제 + 계면활성제), C-0 (미생물) 순으로 높았고 경과시간 81 일에서는 각각 51%, 83%, 63%를 나타내었다. 미세토를 이용한 D군의 경우도 마찬가지의 양상을 보이고 있으나 C군 보다 더 낮은 TPH 제거율을 나타내었으며 미생물과 영양제를 투입한 경우가 가장 높았다. 미세토의 pH는 사질토의 pH 보다 다수 낮거나 유사한 수치를 나타내고 있고, C-0, C-1, C-2의 BTEX 제거율은 14일이 경과한 후 각각 99.8%, 99.4%, 96.0%이며 D-0, D-1, D-2의 제거율은 각각 99.5%, 99.2%, 96.3%로 미생물만 투입한 경우가 가장 높았다.

• 자원리싸이클링
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• 제15권1호
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• pp.12-19
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• 2006

볏짚은 국내에서 유용한 재생 가능한 바이오매스이다. 유동층과 char 분리 장치가 구비된 급속 열분해 장치를 이용하여 볏짚으로부터 바이오오일의 생산에 대한 실험을 수행하였다. 본 연구는 온도변화에 따른 볏짚의 열분해 생성물의 분포와 생성물의 화학적 구성을 알아보고 바이오오일의 활용 가능성을 고찰하고자 했다. 급속 열분해 반응은 $466^{\circ}C,\;504^{\circ}C,\;579^{\circ}C$에서 각각 수행되었다. 유동화 매체로는 생성가스를 사용하였으며 유량은 약 30NL/min 였다. 볏짚의 열분해 결과 기체, 액체, 고체 물질을 얻을 수 있었으며, 기체물질은 GC(TCD, FID)를 이용하여 정성적, 정량적 분석을 하였다. 액체물질은 상등액과 tar가 풍부한 하등액으로 분리하여 발열량, 원소분석, 수분, GC/MS를 통해 화학구성성분을 분석하였다. 고체물질인 char는 원소분석을 하고 그 발열량을 측정하였다. 액체물질인 바이오오일은 화학특성 분석결과 대체 연료유뿐만 아니라 화학 원료물질로서의 사용가능성을 볼 수 있었다.

• 대한가정학회지
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• 제35권4호
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• pp.257-268
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• 1997

The effects of water-and oil-repellent finishes on the deposition and removal of oily soils from polyseter fabrics were investigated in this study. The polyester fabrics treated with three kinds of fluoropolymers(TG-410H, TG-990) were soiled with mixed oily soils and washed by using Terg-O-Tometer at various conditions. It was found that TG-410H and TG-527 treated polyester fabrics reduced significantly the deposition of oily soils than untreated and TG-990 treated polyester fabrics. The removal of oily soils from polyester fabrics was increased in porportion to increasing of surfactant concentration up to a certain point(0.2% owb) but it levelled off above the point. The removal effect was high in the order of TG-990 treated polyester fabrics > untreated polyester fabrics > TG-527 treated polyester fabrics > TBG-410H treasted polyester fabrics. Especially the removal of oily soils from polyester fabrics was more effectively removed in triton X-100 solution. In general the removal of oily soils from polyester fabrics treated with fluoropolymers was increased up to a miximum near 6$0^{\circ}C$ and than decreased above 6$0^{\circ}C$. And efficient removal could be achieved within relatively short time (30min) The removal of oily soils from polyester fabrics was increased in proportion to increasing of pH range up to a certain point(9.5 or 11.0) but it began to decrease above the point. Furthermore the removal of oily soils was increased with th increase of mechanical agitation, but it began to decrease above 160 rpm.