• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.679-688
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• 2000

Dispersants, which are used to break water-in-oil emulsions and to remediate oil-spills, are another water pollutants. In this study, magnetic separation technology was applied to remove dispersants from the sea. Magnetite and maghemite were used as magnetic sorbents and SDDBS, an anionic surfactant and Triton X-100, a nonionic surfactant, were employed as dispersants. Batch experiments were undertaken to study the sorption capacity and sorption equilibrium, and water-bath experiments were conducted to simulate the real situation and to describe the recovery of magnetic particles by the permanent magnet or electromagnet. Maghemite has rather constant removal efficiency for dispersants, regardless of surfactant species. On the other hand, removal efficiency by magnetite is higher for anionic surfactant than maghemite and is higher in distilled water than in seawater which contains more ions. The sorption of dispersants to magnetite is explained by electrostatic attraction and that of maghemite is described not only by electrostatic attraction, but also by structural characteristics that provide high sorption ability and surface condition. Water bath experimental results showed that recovery efficiency of magnetic particle after sorption for dispersants is nearly 100%. It is suggested that this magnetic separation technology is an effective way of dispersant removal because of short operating time, high sorption capacity, and high recovery efficiency of sorbents.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.25-30
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• 2000

The relation between the phase-shift profile for the intermediate frequencies and the Langmuir adsorption isotherm at the poly-$Pt/0.1\;M\;H_2SO_4$ aqueous electrolyte interface has been studied using ac impedance measurements, i.e., the phase-shift methods. The suggested interfacial equivalent circuit consists of the serial connection of the electrolyte resistance ($R_S$), the faradaic resistance $(R_F)$ and the equivalent circuit element $(C_P)$ of the adsorption pseudocapacitance $(C_\varphi)$. The delayed phase shift $(\varphi)$ depends on both the cathode potential (E) and frequency (f), and is given by $\varphi=-tan^{-1}[1/2{\pi}f(R_s+R_F)C_p]$. The phase-shift profile $(\varphi\;vs.\;E)$ for the intermediate frequency (ca. 6Hz) can be used as an experimental method to determine the Langmuir adsorption isotherm (9 vs. E). The equilibrium constant (K) for H adsorption and the standard free energy $({\Delta}G_{ads})$ of H adsorption at the poly-$Pt/0.1\;M\;H_2SO_4$ electrolyte interface are $1.8\times10^{-4}\;and\;21.4kJ/mol$, respectively. The H adsorption is attributed to the over-potentially deposited hydrogen (OPD H).

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.375-375
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• 2010

텅스텐 (110)면에 알루미늄 원자를 흡착시켜 저에너지 전자회절(LEED)과 이온산란분광법(ISS)을 이용하여 흡착구조를 연구하였다. 깨끗한 텅스텐 (110)면 표면에 알루미늄을 0.8ML 흡착시킨 후 1100K 온도로 열처리를 하였을 때 2-도메인의 p($2{\times}1$) LEED 이미지가 관측되었다. Al/W(110)-p($2{\times}1$)계면에서 알루미늄 원자가 텅스텐 표면원자와의 결합거리와 방향 등 3차원적 흡착위치를 알아보기 위해 이온산란분광법을 이용하여 측정하였다. 그 결과 알루미늄 원자는 텅스텐의 두 원자 사이(bridge-site)의 가운데에 위치하였으며, 텅스텐의 첫 번째 원자 층으로부터의 높이는 $2.18{\pm}0.01{\AA}$이다. 알루미늄 원자와 가장 가까운 텅스텐 원자까지의 거리는 $2.57{\pm}0.01{\AA}$이다.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.413-423
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• 2010

Eutrophication caused by the excessive supply of phosphorus to water has been considered as one of the most important environmental problems. In this study, the titanium mesostrcture, which was prepared with the template of different surfactant, was tested to confirm the applicability as an adsorbent for phosphorus removal and evaluate the phosphorus removal efficiency. X-ray diffraction analysis, phosphorus adsorption istotherm and kinetic test were performed for the titanium mesostructure, synthesized at various base material/surfactant molar ratio and with different surfactant templates. From the results, we found that mesostructure was synthesized at the base material/surfactant molar ratio of 1/0.25 was most uniformly and clearly formed and thus the adsorption capacity was also maximized.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.10a
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• pp.134-137
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• 1998

표면처리 한 UF 막으로 오일/물 에멀젼과 오일-SDS/물 어멜젼을 한외여과 시험하였다. 고분자와 계면활성제를 polysulfon막에 흡착시켜 표면을 처리하였다. 오일-SDS/물 에멀젼의 한외여과는 SDS양을 변화시키면서 수행하였다. 다양한 표면처리 한 막으로 한외여과 실험을 회분식 실험방법으로 수행하였다. 표면처리 안한 막에 대한 오일 에멀젼 한외여과시 fouling의 주요 원인이 오일 에멀젼의 흡착이며, 막의 표면처리와 오일 에멀젼에 계면활성제의 주입으로 뚜렷한 fouling의 저감효과가 있었다.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.491-500
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• 2015

Batch experiments were performed to determine the feasibility of the surfactant-enhanced soil washing process at various washing conditions for the Kuwait soil seriously contaminated with the crude oil. The soil was sampled at a dried oil pond in Kuwait and its average TPH concentration was 223,754 mg/kg, which was too high to apply the conventional remediation process. Nine commercialized non-ionic surfactants were used for the batch experiment to measure the surfactant solubility for the crude oil because it was reported that they have worked for the soil remediation. Among them, three surfactants having high crude oil solubility were used for the soil washing experiment. From the result of batch experiment, 5% TritonX-100 washing solution showed the highest TPH removal efficiency (67%) for the crude oil contaminated soil. However, because the residual TPH concentration in the washed soil was still higher than the clean-up level in Kuwait (10,000 mg/kg), the repeated soil washing was performed. After five washings with 2% surfactant solution, the cumulative TPH removal efficiency was higher than 96% and the residual TPH concentration in the soil went down below the clean-up level. To measure the desorption capacity of TritonX-100 remained in the soil after the soil washing, the silica beads and the soil were washed five times with 2% TritonX-100 surfactant solution and then they were washed again with distilled water to detach the surfactant adsorbed on beads or soil. After five washings with surfactant solution, 7.8% and 19.6% of the surfactant was adsorbed on beads and soil, respectively. When additionally washed with distilled water, most of the residual surfactant were detached from beads and only 4.3% of surfactant was remained in soil. From the results, it was investigated that the surfactant-enhanced soil washing process with TritonX-100, Tergitol S-15-7, and Tergitol S-15-9 has a great capability for the remediation of the Kuwait soil seriously contaminated by crude oil (more than 220,000 mg/kg).

• Journal of the Korean Chemical Society
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• v.50 no.4
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• pp.321-327
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• 2006

red 1 and acid blue 92, anionic dyes, were removed from synthetic wastewater by the surfactant-modified clay minerals. Two different clays, such as Korean clay(M78) and Japanese clay(KJ) were treated with three different sulfactants, CTMA, DSDMA and TMSA. The surfactant-modified clay minerals such as M-1(CTMA), M-3(TMSA), KJ-1(CTMA) and KJ-3(TMSA), showed high removal efficiencies with dyes, while M-2(DSDMA) and KJ-2(DSDMA) could adsorb both dyes with relatively low efficiencies. Furthermore, almost 100% absorption of both dyes onto M-1(CTMA) and KJ-3(TMSA) revealed the possibility that these materials can be used for the removal of hazardous organic dyes from wastewater.

• Journal of Soil and Groundwater Environment
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• v.6 no.3
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• pp.21-29
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• 2001

Organobentonite modified with hexadecyltrimethylammonium (HDTMA) was used to quantify adsorption of heavy metals. Adsorption of cadmium and lead increased with increasing pH and soil/solution ratio. Based on these experiments, an optimal soil/solution ratio and an optimal pH was selected. Adsorption experiments with cadmium and lead were conducted to quantify adsorption selectivity on bentonite and organobentonite. Adsorption of heavy metals on organobentonite was slightly reduced relative to bentonite. Because of competition between cadmium and lead, adsorption of each metal was reduced due to the presence of the other. Adsorption selectivity of cadmium was higher than lead. This study used the principle of hard soft-acid-base (HSAB) to interpret adsorption.

• Journal of Adhesion and Interface
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• v.10 no.3
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• pp.141-147
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• 2009

In this study, the high performance hybrid chemical filter (HPHCF) was prepared by web spray using hot melt adhesive. The material of HPHCF was conditionally made of ion exchange resin and PP non-woven fabric. The optimum temperature and pressure for manufacturing of HPHCF conditions were such as $170^{\circ}C$ and 50 psi, respectively. The characteristics of preparated HPHCF and their adsorption properties of ammonia gas were investigated. The ion exchange capacity (IEC) of HPHCF was increased with increasing the resin contents and their values were higher than pure resin and ion exchange fabrics. The removal efficiency for ammonia gas increased with the increase of packing density of hybrid ion exchange fabrics in the column. It showed 13 min which the adsorption breakthrough time was slower than resin and fibers. The maximum value of adsorption for ammonia gas was 98 percent. And also, the velocity was increased with increasing concentration and flow rate of ammonia gas.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.11 no.1
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• pp.32-52
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• 1985