• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.99-107
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• 1997

In this study, a series of batch-scale tests were conducted to optimize the design parameters for the application of soil washing techniques to the hydrophobic organic compounds(HOCs)-contaminated soil and to find the effective methods for the recovery of surfactants from washing effluent by using solvent. Several nonionic surfactants (polyoxyethylene oleyl ester) and sophorolipid were applied to the artificially contaminated soil (4,000 mg n-dodecane/kg dry soil). The effects of washing time, concentration of surfactant solution, dilution ratio, and temperature on washing efficiencies were examined. Hydrophile-liphophile balance (HLB) number was proven to be one of the important parameters for soil washing. The HLB numbers of OA-5 and sophorolipid are too low to form a stable soil-water emulsion. They showed very low washing efficiencies less than 10e1o. If HLB number is in the proper range to form a stable soil-water emulsion, surfactant having higher solubility for HOCs shows higher washing efficiency. OA-14 having higher HLB number than OA-9 formed more stable soil-water emulsion. But its washing efficiency was about 20% due to a lower molar solubility ratio (MSR) than OA-9. OA-9, which forms a stable soil-water emulsion and has comparatively high sotubility for HOCs, showed about 60% washing efficiency by itself. To recover anthracene effectively from OA-9 washing effluent by using benzene as an organic solvent, desirable temperature and pH were $30^{\circ}C$ and 2, respectively.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.628-632
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• 2001

The removal rate of Cl from municipal solid waste incineration(MSWI) ash(bottom ash and fly ash) by washing was investigated. The Cl contents in the bottom ash and fly ash were 2.6-3.0% and 25-30% respectively, and KCl, NaCl, CaCIOH and friedel's salt were main components. From the results on the effects of washing time and temperature, the Cl contents in the bottom ash and fly ash were decreased up to 0.3% and 2.0% respectively by using of water as a solvent within 30 min at 2$0^{\circ}C$, 300 rpm of agitation speed and 10 of liquid/solid ratio. It is expected that the removal of Cl from the incineration ash by washing could make use of the ash for a cement raw material and so on.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.639-646
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• 2004

Metal treated activated carbons are prepared using various metals. Adsorption behaviors, morphologies, as well as antibacterial effects of metal treated samples are compared before and after solvent washing. Adsorption isotherms are used to characterize the porous structure of metal treated activated carbons before and after the solvent washing with acetone or ethyl alcohol. From these data, it is noticed that the changes in physicochemical properties of metal treated activated carbons depend on the solvents employed. Similar results are observed from BET data obtained from nitrogen adsorption isotherms. From scanning electron microscopy (SEM) studies, the changes in shape and size of metal particles are observed after the samples are washed with solvents. These changes result in different blocking effects, which, in turn, affect the adsorption behavior of metal treated activated carbons. X-ray diffraction (XRD) patterns of the samples treated with different metals are different each other. High intense sharp peaks attributed to metals are observed from silver treated samples, while the peaks are not observed from copper treated samples. To compare thermodynamic behavior of metal treated activated carbons washed with different type of solvents, differential scanning calorimetric (DSC) analysis is carried out. The analysis shows similar endothermic curves for all of the samples. Finally, antibacterial effects of metal treated activated carbon against Escherichia coli are discussed. Comparing the effects among the metals employed, highest effects are obtained from Cd, while lowest effects are obtained from Cu. Antibacterial activity becomes higher with the increase of the amount of metals treated, Optimum concentrations of metals to treat activated carbons, obtained from a shake flask test, are known to be 0.4, 0.1, and 0.6 moles for Ag, Cd, and Cu, respectively.

• Analytical Science and Technology
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• v.35 no.6
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• pp.237-241
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• 2022

The effect of washing fingerprints deposited on glass that were contaminated with a flammable liquid (gasoline, kerosene, diesel, and thinner) was studied by washing with hexane or heptane. The fingerprints were visualized using fuming cyanoacrylate, followed by basic yellow 40 staining. After comparing the washing effect, by dividing one fingerprint into four sections, it was confirmed that the ridge detail was damaged by dissolving the fingerprints in flammable liquid. As a result of washing fingerprints contaminated with flammable liquids using hexane or heptane, fingerprints contaminated with gasoline, kerosene, and thinner did not show a washing effect because the ridge detail was damaged at the time of contamination, and only fingerprints contaminated with diesel exhibited improved ridge detail quality. Because hexane and heptane washing damage the ridge detail, it was found that fingerprints contaminated with gasoline, kerosene, and thinner were better enhanced directly without the washing process. In addition, it was found that the amount of the washing solvent and contact time should be minimized when washing fingerprints contaminated with diesel.

• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.44-50
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• 2000

Tolerance mechanism to flupyrazofos was examined with Plutella xylostella (L.) and Spodoptera exigua by investigating the penetration rate of flupyrazofos into larvae body. On determining effective washing of $^{14}C$-flupyrazofos, the washing volume to recover over 98% of $^{14}C$-flupyrazofos was observed at three times (each time: 1 mL). To select a suitable solvent, the recovery rates of each solvent in 3rd instar larvae of DBM were above 98%, but the washing rates of acetone, hexane and ethyl-acetate were 85.1%, 67.2% and 68.4%, respectively. In the BAW larvae, although the recovery rates of each solvent were above 99%, the washing rates of acetone, hexane and ethyl-acetate were 83.5%, 65.9% and 71.7%, respectively. The $PT_{50}$ values of $^{14}C$-flupyrazofos were 0.731 h (44 min) in the DBM larva and 0.504 h (30 min) in the BAW larva. Radiocarbon in acetone washing (external fraction) decreased more quickly in the BAW larva than in the DBM larva, and amount of radiocarbon in larvae body increased more quickly with time in the DBM larva than in the BAW larva. In contrast, amount of radiocarbon in excreta increased more rapidly with time in the BAW larva than in the DBM larva.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.911-912
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• 2008

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.378-384
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• 2010

Regenerated cellulose was prepared from Buckeye wood pulp V60 via dissolution in N-methylmorpholin N-oxide (NMMO) solvent system. The effect of antioxidants such as, n-propylgallate (PG), tris(nonylphenyl) phosphite (TRIS), ethylenediamine tetraacetic acid disodium salt (EDTA), and magnesium sulfate on the properties of regenerated cellulose was studied using X-ray diffraction, copper index calculation, and viscometry. Only addition of more than 0.01% of PG into NMMO solvent was effective to avoid the reduction of the degree of polymerization(DP) of regenerated cellulose during dissolution at $110^{\circ}C$. However, the early stage(within 0.5h of dissolution process) degradation of cellulose was not prevented eventhough up to 0.5% PG was appled to hot NMMO system. In addition, to recover the expensive NMMO after cellulose regenerating process, the washing filtrate was studied using simple techniques, such as refractive index, pH, and conductivity measurements. Through conductivity measurement result, 4-time of washing was enough to remove the NMMO completely from regenerated cellulose.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.780-785
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• 1990

In order to establish the effective extraction and purification process of rapeseed protein, the extraction solvents were compared with one another ; and the residues of glucosinolate and phytate and the extraction yield of protein, which had been extracted by 1% sodium hexa mata-phosphate(SHMP) and purified through isoelectric precipitation, acid-washing and UF concentration, were investigated. As for the condition for extraction of rapeseed proteins, the solvent of 1% SHMP(pH 8.0) turned out the most appropriate ; so far as the purification process for the elimination of glucosinolate and phytate was concerned, the acid-washing twice or the process of the acid-washing once and UF concentration was considered the most effective. The yield and content of rapeseed protein were 37.1% and 75.3% respectively in the case of the acid-washing twice, 42.1% and 72.4% respectively in the case of the acid-washing once and UF concentraction, Consequently, with the elimination effects of glucosinolate and phytate put into consideration, the process of isoelectric precipitation, acid-washing once(pH 3.5), neutralizing(pH 7.5), UF concentration and then freeze drying proved the most effective purification process.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.6
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• pp.50-57
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• 2012

In this study, the beeswax extraction methods using organic solvents were examined to develop a optimal dewaxing technology for beeswax-treated Hanji. Thermally-aged beeswax-treated Hanji was dewaxed using four types of extraction methods including dipping, Soxhlet extraction, ultrasonic washing and shaking methods. Then, the aging stability of the dewaxed Hanji was evaluated in terms of variations in paper strength and in the color of the printed area with muk. The experimental results suggested that the dewaxing methods allowing solvent to flow during extraction showed superior extraction efficiency. The dipping method in which the organic solvent does not flow showed the slowest extraction rate of beeswax compared to three other methods. In terms of variations in tensile strength and folding endurance, however, no obvious differences in the aging stability were observed amongst these four extraction methods. Regarding the aging stability in terms of the color of the printed area with muk, Soxhlet extraction method showed the best performance of dewaxing.

• Clean Technology
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• v.2 no.1
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• pp.47-52
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• 1996

The solvent extraction method was applied on a spent solution containing copper, which was produced in a printed circuit board process, to recover copper and to reuse the etching solution. Lix 64 N ($\alpha$-Hydroxyoxime + $\beta$-Hydroxybenzophenone Oxime) was used as a solvent. The acidic spent copper solution was mixed with and alkaline copper solution to pH=2. The solvent including 30 volume% of Lix 64 N extracted 17.1gr/l of copper from the mixed spent copper solution. In the continuous bench scale experiment, 4 stages for extraction, 2 stages for stripping and 4 stages for washing were used. Recovered copper was recycled as copper sulfate and the raffinate was reused as copper etchant. The percentage of copper recovery and the purity of copper sulfate were higher than 99.9%, respectively.