• Journal of the Korean Chemical Society
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• v.61 no.4
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• pp.143-150
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• 2017

Countercurrent oxidation process (COP) was developed and evaluated for treatment of highly concentrated PCB containing insulating oil. The PCB content in insulating oil taken from Haksanmetal company was found to be 1,512 ppm. The COP utilizes a self-sustained flame which propagates itself in a direction counter to the oxygen flow. The flame removes PCBs adsorbed in activated carbon and, at the same time, regenerates activated carbon. The flame temperature was determined from both mass loss of activated carbon and the relative ratio of CO and $CO_2$ exhausted during COP, and showed that its temperature lied in the range of $650-850^{\circ}C$. Removal efficiency of PCBs was achieved above 99.99% for 5% of insulating oil loaded activated carbon with 1 COP in weight ratio. Also, the same removal efficiency was acquired for 60% of insulating oil loaded activated carbon with three consecutive COP. In addition, specific surface area of activated carbon during COP was recovered to almost similar value of virgin activated carbon. It proved that the COP was much effective in removing high concentration of PCBs in insulating oil easily and affordably.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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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.

• Journal of Environmental Health Sciences
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• v.33 no.5
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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.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.191-193
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• 2000

To find out the countermeasure to plant damage at soil contaminated with oil, several adsorbents such as muck, peat, sawdust and PEAT SORB were treated at diesel oil contaminated soil. As the results, sawdust and PEAT SORB showed better effect of oil adsorption than muck and peat. Removal rate of diesel oil with sawdust treatment was higher than 95% at the condition which the ratio of adsorbent amount to oil was higher than 1:2(w/v). And the releasing amount of oil from adsorbent-oil complex was very small. With the oil treatment of $4,000\;L{\cdot}ha^{-1}$ at tillering stage, rice plant height and chlorophyll content were lower than control at non-adsorbent treatment, but those were increased at sawdust treatment.

• Tribology and Lubricants
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• v.38 no.3
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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.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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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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• v.43 no.4
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• pp.487-494
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• 2005

Nowadays a large amount of wastewater containing metal working fluids and cleaning agents is generated during the cleaning process of parts working in various industries of automobile, machine and metal, and electronics etc. In this study, aqueous or semi-aqueous cleaning wastewater contaminated with soluble or nonsoluble oils was treated using ultrafiltration system. And the membrane permeability flux and performance of oil-water separation (or COD removal efficiency) of the ultrafiltration system employing PAN as its membrane material were measured at various operating conditions with change of membrane pore sizes and soil concentrations of wastewater and examined their suitability for wastewater treatment contaminated with soluble or insoluble oil. As a result, in case of wastewater contaminated with soluble oil and aqueous or semi-aqueous cleaning agent, the membrane permeability increased rapidly even though COD removal efficiency was almost constant as 90 or 95％ as the membrane pore size increased from 10 kDa to 100 kDa. However, in case of the wastewater contaminated with nonsoluble oil and aqueous or semi-aqueous cleaning agent, as the membrane pore size increased from 10 kDa to 100 kDa and the soil concentration of wastewater increased, the membrane permeability was reduced rapidly while COD removal efficiency was almost constant. These phenomena explain that since the membrane material is hydrophilic PAN material, it blocks nonsoluble oil and reduces membrane permeability. Thus, it can be concluded that the aqueous or semi-aqueous cleaning solution contaminated with soluble oil can be treated by ultrafiltration system with the membrane of PAN material and its pore size of 100 kDa. Based on these basic experimental results, a pilot plant facility of ultrafiltration system with PAN material and 100 kDa pore size was designed, installed and operated in order to treat and recycle alkaline cleaning solution contaminated with deep drawing oil. As a result of its field application, the ultrafiltration system was able to separate aqueous cleaning solution and soluble oil effectively, and recycle them. Further more, it can increase life span of aqueous cleaning solution 12 times compared with the previous process.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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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).

• Journal of Soil and Groundwater Environment
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• v.22 no.2
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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).