• YAKHAK HOEJI
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• v.11 no.3_4
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• pp.17-21
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• 1967

At present, quarternary ammonium salts(cationic surfactant) and Tego compounds (amphoteric surfactant) are used as germicidal agent. In this paper, it was investigated whether their germicidal activities are influenced or not by some suspending agents which are added to them 0.005% benzalkonium chloride aq. solution and 0.05% dodecyl diaminoethyl glycine aq. solution sterilized respectively against Staphylococcus aureus and Escherichia coli within a minute. The solutions aded acacia, carboxymethyl cellulose, sodium alginate solutions to make to 0.005% to above surfactants solution decreased the germicidal activity, not being sterilized bacteria for more than 2 hours however, the solutions decreased the germicidal activity by addition of suspending agents such as acacia, carboxymethyl cellose, sodium alginate and bacteria were survival for more than 2 hrs, 0.05% of benzalkonium chloride and 0.1% dodecyl diaminoethyl glycine respectively would be sterilized within 10 minutes, when added to 5% suspending agents. This result show that bactericidal action of dodecyl diaminoethyl glycine is affected by suspending agents less than that of benzalkonium chloride.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.3
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• pp.359-365
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• 1995

The drag reduction phenomenon with an additives of surfactant(STAC, stearlytrimethyl ammonium chloride) and polymer(PEO, polyethlene oxide) was investigated in fully developed turbulent pipe and channel flows at various low Reynolds numbers as well as very low additives concentration. A maximum of 70% drag reduction compared with plain water flow was found. This maximum drag reduction percentage obtained with surfactant solution was slightly higher than that of the Virk's asymptote in polymer solution.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.70-73
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• 2013

Solubility of oil contaminants in surfactant solutions plays an important role in selecting a suitable surfactant type for soil remediation. Solubility measurement procedures consist of making an equilibrium between surfactant solution and oil, solvent extraction using dichloromethane, and condensation for gas chromatography analysis. Solubility measurement requires time consumption and lots of materials. Interfacial tension is the contracting force between two immiscible liquids, surfactant solution and oil, and also closely related to solubility of oil. This study established a relationship between the interfacial tension and solubility of diesel fuel in surfactant solution and suggested a quick method to estimate solubility of oil in a surfactant solution by measuring its interfacial tension. The results of this study showed that the solubility of diesel fuel in surfactant solution was exponentially increased by decreasing the interfacial tension between two immiscible liquids. The solubility of diesel fuel was significantly increased under the interfacial tension conditions below 1 dyne/cm, while the solubility change was not apparent under the interfacial tension conditions beyond 5 dyne/cm. Interfacial tension measurements may allow us to quickly select an efficient surfactant and its concentration for soil remediation.

• Journal of Soil and Groundwater Environment
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• v.16 no.5
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• pp.90-96
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• 2011

Simultaneous removal of heavy metals (Cd, Pb) and diesel-fuel from a soil column was evaluated by respectively flushing with sodium dodecyl sulfate (SDS) solution, mixture of SDS and sodium iodide (SDS + NaI), and surfactant foam (SDS + NaI foam). First, this study evaluated these flushing methods to the heavy metals only-contaminated soil for removal of heavy metals from the heavy-metal only contaminated soil column. After 7 pore volume flushing of the soil column, Cd removal efficiencies from the soil were 40% by SDS solution, 50% by SDS + NaI mixture, and 60% by surfactant foam. The flushing results implied that anionic surfactant and ligand can be efficiently applied to extraction of Cd from the heavy metal contaminated soil. Furthermore, surfactant foam flushing showed an increased flushing efficiency with enhancing the contact between surfactant solution and soil. However, Pb removal efficiency by these flushing methods did not show any difference unlike those of Cd. Second, this study eventually evaluated flushing methods for simultaneous removal of heavy metals and diesel-fuel from the soil column with 7 pore volume flushing. Diesel-fuel removal efficiencies were 50% by SDS + NaI flushing and 90% by SDS + NaI foam flushing. Cd removal efficiency by the foam flushing reached to 80% which was higher than the result of the previous heavy metals onlycontaminated soil experiment. This result implied that diesel-fuel could act as a metal-solvent while it contacted to heavy metals present in the soil. This study clearly showed that surfactant foam flushing simultaneously removed heavy metals and diesel fuel from the soil column.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.824-830
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• 2006

Several tests were conducted to optimize the design parameters of ln-situ soil flushing processes for diesel contaminated soil. According to the batch extraction test for three anionic surfactants evaluation, Calgonit limiting bubble occurrence was selected for its higher oil cleaning efficiency. After optimum surfactant selection, there were many sets of column flushing test. Over 70% of BTEX was removed in this surfactant dose with 400% of soil volume. In the case of no surfactant addition flushing in column, so called "blank flushing test", BTEX removal rate was 64%. But when we reused the effluent for the cleaning solution, the removal rate was decreased to 46.9%. This result showed reabsorption of oil occurred on the soil. With the addition of Calgonit solution to the diesel contaminated column, BTEX was removed up to 98.9% during the first flushing and 99.4% for the second recirculation flushing. In microcosm tests, diesel contaminated soils were cleaned by both surfactant flushing and biological activities. In anoxic condition, nitrate was used as an electron acceptor while the surfactant and the oil were used an electron donor. BTEX removal efficiency could be achieved up to 80% by biological degradation.

• Journal of the Korean Applied Science and Technology
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• v.15 no.2
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• pp.25-32
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• 1998

The emulsion stability of W/O emulsion prepared by D phase emulsification during storage and handling is studied by using phase diagrams. The process of D phase emulsification begins with the formation of isotropic surfactant solution, followed by formation of oil-in-surfactant (O/D) gel emulsion by dispersion of octamethylcyclotetrasiloxane(OMCS) in the surfactant solution. Polyols were essential components for this purpose. To understand the function of polyols, the solution behavior of nonionic surfactant/oil/water/polyol systems were investigated by the ternary phase diagrams of polyoxyethylene oleyl ether/OMCS/propylene glycol(PG) aqueous solutions. The addition of PG increased the solubility of oil in the isotropic surfactant phase. D phase emulsification method has been applied to a new type of cosmetics. By using this emulsification technique, O/W emulsion were formed without a need for adjust of HLB. Fine and stable W/O emulsions were prepared by D phase emulsion.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.8
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• pp.1097-1103
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• 2000

This research was concerned with the enhancement of heat transfer by surfactant added to the aqueous solution of LiBr. Different horizontal tubes were tested with and without an additive of normal octyl alcohol. The test tubes were a bare tube, floral tube and hydrophilic tube. The additive mass concentration was about 0.05${\sim}$5.5%. The heat transfer coefficient was measured as a function of solution flow rate for the range of 0.01${\sim}$0.034 kg/ms. The experimental results were compared with cases without surfactant. The enhancement of heat transfer by Marangoni convection effect generated by the addition of the surfactant is observed in each test tube. The increase of heat transfer coefficient by surfactant addition is about 35${\sim}$90% for bare tube, 40${\sim}$70% for the floral tube, 30${\sim}$50% for the hydrophilic tube and was higher for the cases with smaller a little solution flow rates.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.226-233
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• 2007

In this study, the effects of additives such as ionic surfactant and cosurfactant were studied on the solubilization of sulfur compounds contained in the crude oil by Tergitol series nonionic surfactants. It was found that the addition of an ionic surfactant such as sodium oleate, potassium oleate, CTAB and DTAB did not enhance solubilization capacity of Tergitol series nonionic surfactant. On the other hand, the addition of a long-chain alcohol as a cosurfactant increased the solubilization of sulfur compounds in the crude oil. The effect of alcohol was found to become reduced with an increase in the amount of crude oil used mainly due to partitioning phenomena of an nonionic surfactant. The enhancement of solubilizing capacity of Tergitol series nonionic surfactant with addition of a cosurfactant was associated with a decrease in interfacial tension between crude oil and surfactant solution. The pH of Tergitol nonionic surfactant solution did not affect the solubilization of sulfur compounds. Finally, it was found that the growth of sulfur reducing microoganisms was not greatly affected by both addition of nonionic surfactant and cosurfactant.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.259-264
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• 2015

For the enhanced oil recovery, one of the most important factors is to determine the surfactant formulation in chemical flood. The objective of this study is to analyze the microemulsion formed between the alkali-surfactant (AS) solution and A crude oil for screening surfactants. The alkali-surfactant solution was manufactured by using the surfactant purchased from AK ChemTech. $C_{16}-PO_7-SO_4$ and sodium carbonate solution were used as surfactant and alkaline, respectively. Both TEGBE and IBA were used as a co-solvent. The AS solution and A crude oil can form a Type III middle phase microemulsion at the salinity from 0.0 wt%~3.6 wt%. Increasing the salinity causes the phase transition of microemulsion from the lower (Type I) to middle (Type III) to upper (Type II) phase. Interfacial tension (IFT) values calculated by Huh's equation were in good agreement with ultralow IFT. According to this characteristic, the surfactant purchased from a domestic company can be applied to the enhanced oil recovery.

• Journal of the Korean Applied Science and Technology
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• v.24 no.2
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• pp.160-166
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• 2007

The rheological properties and surface tensions of polymer solutions and polymer-surfactant mixed solutions were investigated. The polymers used in this study were a homopolymer of acrylic acid crosslinked with an allyl ether of pentaerythritol, an allyl ether of sucrose, or an allyl ether of propylene (CARBOMER), acylate/C10-30 alkyl acylate crosspolymer (AAAC), and ammonium acryloydimethyltaurate/VP copolymer (ADTV). A solubilizing agent PEG-40 hydrogenated castor oil (HCO-40) and an emulsifying agent polyoxyethylene (20) sorbitan monostearate (POLYSORBATE 60) made the micelles intervening between AAAC polymers, resulting in the increase of viscosity. However, HCO-40 made this behavior over the wider range of surfactant concentration than POLYSORBATE 60. From the view point of surface tensions in the same range of surfactant concentration, AAAC/HCO-40 solution showed the area of increasing surface tension with surfactant concentration in contrast to the AAAC/POLYSORBATE 60 solution showing no increasing area.