• 대한화학회지
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• 제61권4호
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• pp.143-150
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• 2017

절연유에 높은 농도로 함유되어 있는 폴리염화바이페닐(PCB)을 처리하기 위해서 역류산화공정이 개발되었고 그 평가가 이루어졌다. 학산금속공업(주)로부터 구한 절연유 중의 PCBs의 함량은 1,512 ppm이었다. 역류산화공정은 산소의 흐름 속도와 반대되는 방향으로 자기 스스로 이동하는 자발적인 불꽃을 이용한다. 불꽃은 활성탄에 흡착되어 있는 PCBs를 제거함과 동시에 활성탄을 재생시킨다. 불꽃의 온도는 활성탄의 질량 손실과 역류산화공정 동안 배출되는 CO와 $CO_2$의 상대적인 비에 의해 결정하였고, 온도는 $650{\sim}850^{\circ}C$의 범위를 보였다. PCBs의 제거 효율은 무게비로 활성탄에 5%가 적재된 절연유를 1번의 역류산화공정을 거쳤을 때 99.99%이상을 나타내었다. 또한 60%의 절연유를 활성탄에 적재하여 3번의 연속적인 역류산화공정을 거쳤을 때 같은 제거 효율을 얻었다. 덧붙여서, 역류산화공정 동안 활성탄의 비표면적은 신탄의 수치와 비슷한 수준으로 회복되었다. 역류산화반응은 쉽고 경제적으로 절연유에 있는 고농도의 PCBs를 제거하는데 대단히 효과적이다는 것을 증명하였다.

• 한국환경농학회지
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• 제19권3호
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• pp.191-193
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• 2000

경유로 인한 농작물 피해를 줄이기 위한 방법으로 톱밥처리 효과를 구명하기 위하여 톱밥의 경유 흡착능과 시용 효과를 상탄(上炭(Muck)), 이탄(泥炭(Peat)) 및 PEAT SORB 등과 비교, 검토한 결과, 흡착제 종류별 경유 제거효율은 톱밥과 PEAT SORB가 토탄 및 이탄에 비해 높았다. 톱밥의 경유 제거효율은 경유에 대한 처리 비율이 1:2(w/v)이상일 때 97% 이상으로 높게 나타났으며, 흡착된 경유의 재용출은 거의 없었다. 경유오염 토양에서의 톱밥 처리효과는 분얼기에 $4,000L{\cdot}ha^{-1}$의 경유를 처리하고 흡착제를 처리하지 않은 구에서는 초장과 엽록소 함량이 대조구에 비해 감소한 반면 톱밥 처리구에서는 생육이 좋았다.

• 한국환경보건학회지
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• 제33권5호
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• pp.462-469
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• 2007

Isolation and application of oil-degradation microbes from the oil-contaminated soil and the determination of optimal operation conditions about the peat moss, the addition for the oil-biodegradation. After all experiments, we have acquired three important conclusions: First, we found out the 4 microbes, Pseudomonas fluorescens, Pseudomonas aeruinosa, Kurtia sp., Bacillus ceres, with excellent capability for the oil-degradation; Second, the optimal operating conditions of the peat moss for TPH treatment were pH $7{\sim}8$, temperature $25{\sim}30^{\circ}C$, water content 20%, mixing 2 times/ day, addition volume 2%; Third, in case of the application to the oil-contaminated soil with 4 mixed microbes, the removal efficiency of TPH was increased from 54% to 83% in oil-contaminated soil and from 65% to 85% in oil-contaminated soil with the peat moss.

• Tribology and Lubricants
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• 제38권3호
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• pp.109-114
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• 2022

This paper reports the development of an oil flushing system combined with a microbubble generator. Oil flushing plays a crucial role in regulating the lubricant's performance during the lubricant replacement process. Moreover, harmful contaminants, such as sludge, wear particles, and rust, from piping systems or lubrication system can be removed by oil flushing. Oil flushing aims to increase the system's efficiency using a dedicated flushing oil, increasing of the supply pressure and generating a vortex. In addition, it helps the mechanical system or equipment achieve peak performance and reduces the potential for premature failure. However, the contaminant-removal applications of existing oil flushing system are limited. In this research, we aim to improve the performance of oil flushing system by incorporating a microbubble generator, which uses the venture effect to generate microbubbles and mixes them with lubricant. The microbubbles in the blended lubricant remove contaminants from the lubrication system more effectively. Structural mechanics and fluid dynamics are analyzed through fluid-structure interaction (FSI) analysis, and the numerical analysis results are used for the designing the system. The magnitude of the maximum stress is investigated based on the pressure results obtained by the CFD analysis; through the CFD analysis, the mixing ratio of air (bubble) and lubricant is evaluated using the volume of fluid (VOF) model according to the working conditions.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.13-17
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• 2008

This paper deals with the directional mobility of droplets on structured surfaces. Structured surfaces were micro-patterned with rectangular lines and spaces of varying pitch and height in the sub-millimeter range. The material used was polydimethylsiloxane, which is hydrophobic and wettable by oil. First, we studied the effect of the structural design on the sliding angle of pure water or oil through experiments. For pure water droplets, we found that a wider pitch enhanced the directionality. On the other hand, oil droplets spread along the groove because of their low surface tension and strong capillary force. The directionality of the sliding angle of oil droplets was larger than that of pure water, especially when the groove was narrower and deeper. Second, we poured a large amount of liquid on the structure and evaluated the removal rate on the tilted surface. We found that a parallel structure enhanced the liquid mobility for both pure water and oil.

• 한국물환경학회지
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• 제20권5호
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• pp.447-451
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• 2004

The various pretreatment processes were evaluated to remove organic pollutants of weathered oil contaminated seawater(WOCS) for reverse osmosis desalination process, Biodegradation, coagulation, ultrafiltration, advanced oxidation processes and granular activated carbon filtration were used to evaluate the potential of organic pollutants removal in WOCS. Dissolved Organic Carbon(DOC) was almost not removed by biodegradation in WOCS. DOC was removed by 25% and 10% with the addition of $FeCl_3$ and PAC in WOCS, respectively. The removal efficiency using ultrafiltration(WOCS 500) was about 20% of DOC and 40% of $E_{260}$, respectively. In AOP application of WOCS, the removal of organic materials was improved up to 60% by the combination of $UV/O_3$ compared to UV process. However, 98% of DOC in woes could be removed by granular activated carbon filtration. It is revealed that activated carbon filtration is the best process for the pretratment of DOC removal.

• Korean Chemical Engineering Research
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• 제43권4호
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• pp.487-494
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• 2005

자동차, 기계금속, 전자 등 여러 산업에서는 부품 가공 중의 세정 과정에서 금속가공유와 각종 세정첨가물이 함유된 많은 폐수를 발생시킨다. 본 연구에서는 수용성 또는 비수용성 금속가공유로 오염된 수계 및 준수계 세정폐수를 한외여과막시스템을 이용하여 처리하고자 하였다. 이 실험에서 막을 친수성인 polyacrylonitrile(PAN)을 사용하고 막의 크기 및 오염물의 농도 변화에 따른 한외여과막 투과수량과 유수분리 성능(COD제거율)을 측정하여 한외여과법 처리의 적정성 여부를 조사 분석하였다. 그 결과 수계 또는 준수계세정제와 수용성 가공유로 오염된 가공폐수의 경우 한외여과막의 크기가 10 kDa에서 100 kDa로 증가함에 따라 COD 제거율은 90 wt％-95 wt％로 거의 일정하지만 투과플럭스는 4배 이상 증가하였다. 그리고 금속가공폐수의 오염물 농도가 3 wt％에서 10 wt％로 증가할수록 한외여과막의 COD 제거율은 증가하지만 투과플럭스는 감소하였다. 그러나 수계 또는 준수계세정제와 비수용성 오일로 오염된 가공폐수의 경우 오염물의 농도가 증가할수록 COD 제거율은 거의 일정하지만 투과플럭스는 급격히 감소함을 보여 주었다. 이러한 현상은 한외여과막 재질이 친수성인 PAN이기 때문에 비수용성 오일이 막을 통과하지 못하고 막의 기공을 막기 때문인 것으로 추론된다. 따라서, 수용성 오일이 함유된 세정액은 막재질이 PAN이고 세공크기가 100 kDa인 한외여과법 처리가 적정한 것으로 판단되었다. 이러한 기초실험 결과를 활용하여 PAN 재질의 막(MWCO=100 kDa)을 사용한 한외여과 pilot 시스템을 설치 운전하여 수용성 인발유로 오염된 알칼리 세정 폐액을 처리하고 알칼리세정제와 인발유를 재활용하고자 하였다. 현장 실험 결과 한외여과 공정은 수계세정제와 수용성오일을 효과적으로 분리하여 재활용할 수 있었고 기존 공정에 비하여 세정제 사용수명을 12배 이상 증가시킬 수 있었다.

• 한국생산제조학회지
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• 제20권1호
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• pp.13-16
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• 2011

It is a tendency where the number of the restaurant is increasing recently with advancement of the food service industry. In comparison, Noxiousness fine MIST and the removal are passively done in about offensive odor which occurs meat products processing as emitting like that in the atmosphere. Because adherence lamination in the exhaustion line pipe has need of a periodic cleaning and change, it must discontinue the business of long time. In this paper, The technique development on fine MIST, dust of offensive odor and filtering which occur meat products processing prevents adherence/lamination of fine MIST in exhaustion line pipe. And the source prevents the environmental matter which is emitted in the atmosphere under maximizing boil offensive odor and the filtering effect of noxiousness MIST.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.198-201
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• 2002

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, a slurry circulation system was designed and manufactured. Its finishing characteristics was experimently investigated by various effective factors such as dry, water flow, oil flow with a slurry. From the experimental results, it was found that the materal removal and surface roughness were good in oil flow with slurry. The slurry circulation system is effective on the internal finishing of non-ferromagnetic pipe(SUS304).

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권2호
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• pp.33-40
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• 2017

In typical remediation practices, separate washing systems have to be applied to clean up the soils contaminated with both oil and heavy metals. In this study, we evaluated the efficiency of successive two-stage soil washing in removal of mixed-contaminants from soil matrix. Two-stage soil washing experiments were conducted using different combinations of chemical agent: 1) persulfate oxidation, followed by organic acid washing, and 2) Fenton oxidation, followed by inorganic acid washing. Persulfate oxidation-organic acid washing efficiently removed both organic and inorganic contaminants to meet the regulatory soil quality standard. The average removal rates of total petroleum hydrocarbons (TPH), Cu, Pb, and Zn were 88.9%, 82.2%, 77.5%, and 66.3% respectively, (S/L 1:10, reaction time 1 h, persulfate 0.5 M, persulfate:activator 3:1, citric acid 2 M). Fenton oxidation-inorganic acid washing also gave satisfactory performances to give 89%, 80.9%, 87.1%, and 67.7% removal of TPH, Cu, Pb, and Zn, respectively (S/L 1:10, reaction time 1 hr, hydrogen peroxide 0.3 M, hydrogen peroxide:activator 5:1, inorganic acid 1 M).