• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1997-2001
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• 2010

Generally, railroad soil around turnout was caused by leakage of lubricant oils during its maintenance. So, TPH concentration in soil was much higher than standard in Soil Envirnment Law. In additiont, railroad site was still difficult to assess due to railcar operation. This research was conducted to investigate the effect on electrolyte concentration during the Electrokinetic-Fenton process for contaminated soil around railroad turnout. As a result, experimental result shows that TPH removal in soil and amount of EOF were changed depending on electrolyte concentration. In future, the removal efficiency can be enhanced to optimize concentration in EK-Fenton Process.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권2호
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• pp.33-44
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• 2009

본 연구의 목적은 국내 폐광산 지역 광미 등과 같은 비소 오염토양을 효과적으로 정화할 수 있는 생물학적 기술과 물리화학적 기술을 연계한 통합 기술을 개발하는 것이다. 이를 위해 폐광산이 송천 광산에서 비소를 다량 함유하고 있는 광미를 채취하여 비소와 중금속 함량을 정량적으로 분석하고 광미의 다양한 물리화학적 특성과 광물조성 등를 파악하였다. 그리고 광미 내 존재하는 비소와 중금속 종들의 존재형태별 상대함량을 분석하여 각 원소들의 용출성과 이동도를 예측하기 위하여 연속 추출법을 이용하였다. 이러한 광미와 광미내 존재하는 비소 및 중금속 오염물질의 기본적인 지구화학적 분석 자료를 바탕으로 비소의 생용출 (bioleaching)에 대한 컬럼실험을 수행하였다. 그리고 생용출과 전기동력학적 공정을 연계한 통합공정으로 비소를 제거한 실험을 실시하여 전기동력학 단일공정만 적용했을때와의 비소의 제거효율을 비교하여 통합공정의 적용 가능성을 평가하였다. 연구결과, 동일한 조건에서44일간 운전하였을 때 전기동력학 공정만을 개별적으로 적용했을 ��와 생용출(28일)과 전기동력학 (16일) 기술을 연계한 통합공정을 적용했을 ��의 비소 제거효율은 각각 57.8%와 64.5%로 나타났다. 그리고 생용출 (28일)에 의한 비소 제거효율은 11.8%정도로 상대적으로 매우 낮게 나타나서, 생용출은 비소를 제거하기 위한 공정이라기보다는 비소의 이동도를 증가시키는 공정으로, 이후 연계하여 적용되는 전기동력학적 공정에 의한 비소의 제거효율을 향상시키는 것으로 판단된다. 특히 전기동력학 공정을 단독으로 적용했을 때보다 생용출 공정을 연계했을 때 비소의 제거 속도가 두 배 이상으로 증가하는 것을 알 수 있었다. 이러한 결과는 비교적 경제적인 생용출 공정을 충분히 적용한 후 전기동력학적 공정을 적용하게 된다면, 비소의 제거효율 분만 아니라 제거속도 또한 향상된다는 것을 뒷받침해 줌으로써 두 기술을 연계한 통합공적의 적용 가능성과 향상성을 입증한다고 하겠다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.128-131
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• 2003

To clarify the effect of soil property on the EK-Fenton remediation of the soil contaminated with phenanthrene, this research had been conducted. In the experiments using EPK kaolinite, the $H_2O$$_2$ stability and effect of phenanthrene treatment improved more than that in the experiments using Hadong clayey soil. The results signify that Fe oxide content and acid buffer capacity significantly affected the fate of $H_2O$$_2$ and phenanthrene during the EK-Fenton process.

• 한국염색가공학회지
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• 제1권1호
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• pp.19-25
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• 1989

In past, dye diffusion and dyeing rate in fibers have been emphasized in dyeing phenomena. However, in the light of the properties of colloids in the surface of disperse phase and dispersion, there exist specific characters such as adsorption or electric double layer, which seems to play important roles in determining the physiochemical properties in the dyeing system. Electrostatic bonding, hydrogen bonding and Van der Waals adsorption are common in dyeing as well as covalent bonding. Particularly, electrostatic bonding is premised on the existance of ionic radicals in fibers. The present study was aimed to clarify the electrokinetic phenomena of dyeing through the role of electric double layer by ion in amphoteric fibers with different ionic effects under different pH. Spectrophotometric analysis method was used to compare dyeing condition of surface, which can be detected by electrokinetic phenomena and the inner of fibers after deceleration of dyed fibers. Nylon and wool, the typical amphoteric fibers were dyed with monoazo acid dyes such as C.I. Acid Orange 20, and C.I. Acid Orange 10. Various combinations were prepared by combining pH, temperature and dye concentration, in order to generate streaming electric potential which were measured by microvolt meter and specific conductivity meter. The results were transformed to zeta potential by Helmholtz-Smoluchowski formular and to surface electric charge density by Suzawa formular, surface dye amount, and effective surface area of fibers. The amount of dyes of inner fibers were also measured by the Lambert-Beer’s law. The main results obtained are as follows. 1. By measuring zeta pontential, it was possible to detect the dyeing mechanism, surface charge density, surface dye amount and effective surface area concerning dye adsorption of the amphoteric fibers. 2. Zeta pontential increases in negative at low pH and high dye concentration in the process of dyeing. This implied that there existed ionic bond formation in the dyeing mechanism between acid dyes and amphoteric fibers. 3. Dibasic acid dye had little changing rate in zeta potential due to the difference in solubility of dye and in number of dissociated ions per dye molecule to bond with amino radicals of amphoteric fibers. The dye adsorption of mono basic acid dye was higher than that of dibasic acid dye. 4. The effective surface areas concerning dyeing were $6.3E+05\;cm^2/g$ in nylon, $1.6E+07\;cm^2/g$ in wool fiber being higher order of wool then nylon.

• 한국지하수토양환경학회지:지하수토양환경
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• 제7권3호
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• pp.85-94
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• 2002

본 연구의 목적은 토양입자에 대한 전기화학적 특성을 평가함으로써 동전기 기술을 실제 현장에서 적용시, 오염물을 효과적으로 제거하기 위한 최적 운전방법이나 인자를 도출하는 것이다. 토양입자의 제타포텐셜을 토양용액의 pH와 계면활성제의 농도에 대하여 측정하여 전기삼투압적 흐름방향 및 흐름율과의 관계를 분석하였다. 동전기 실험동안, 전기삼투압 투과율($k_e$), 전기전도도($\delta_e$) 및 전압분포에 대한 측정을 실시하였다. Kaolinite의 PZC는 4.2정도로 측정되었으며 pH가 증가할수록 제타포텐셜 감은 점점 음의 값이 증가하는 경향을 나타내었다. 주입된 계면활성제 또한 토양 표면의 전기화학적 특성에 영향을 주어 제타포텐셜 값을 변화시키는 결과를 나타내었다. 동전기 실험이 진행되는 동안, 토양시료의 대부분에 걸쳐 낮은 pH값을 나타내었으며 이로 인하여 용액과 전기적 흐름이 낮아지는 결과를 초래하였다. 또한, 전압 분포도 시간에 따라 변화하여 용액과 전기적 흐름 특성에 영향을 주었다. 결과적으로, 낮은 pH에 의한 토양의 제타포텐셜 값의 변화와 구간별로 다른 전압차분포로 인하여 용액과 전기적 흐름이 영향을 받는다는 결과를 본 연구로부터 얻었다. 효과적인 동전기 공정의 적용을 위하여 인위적인 토양 용액의 pH 조절이나 토양의 전기적 특성을 변화시키는 물질 등을 동시에 주입함으로써 오염물을 제거하는 용매의 흐름이 계속적으로 높게 유지되도록 하는 방안이 필요하다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1061-1064
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• 2008

A completion of settling process takes a lot of time for dredged materials of high moisture content, such as contaminated sludge, in landfill site. In general, additives (e.g. flocculants) are used for reducing settling time of such colloidal material, which results in the increase of sludge volume, and hence much space is required in landfill site. This study is to suggest alternative method in order to enhance the settling process of cohesive clayey soils. A number of gravitational sedimentation tests as well as electrokinetic experiments were conducted to investigate the variation of initial moisture content on the settling behaviour of clay slurry. Surface settlement, electric current and local voltage gradient were monitored during the experiment, and moisture content and soil pH were measured after the experiment. From the results, the application of electrokinetics was found to be effective in volume reduction (i.e. increase of settling velocity and decrease of final moisture content) by comparison with gravitational settling process.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권4호
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• pp.142-144
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• 2004

To use Poly-dimethylsiloxane (PDMS) for the electrokinetic flow channel, the PDMS surface must be modified to be hydrophilic. With $O_2$ plasma treatment, it is difficult to maintain hydrophilicity for more than one day. In this paper, we present the chemical modification of the PDMS surface using 2-Hydroxyethyl methacrylate (HEMA) to prolong hydrophilicity lifetime. The oxide radicals generated temporarily on the PDMS surface by $O_2$ plasma are grafted with HEMA. Once the PDMS samples have been grafted, they demonstrate improved hydrophilicity retainment and electroosmotic flow characteristics compared to the untreated PDMS and the oxidized PDMS following the $O_2$ plasma process. This phenomenon was verified by the contact angles, Fourier transform infrared (FTIR) spectra and electro osmotic flow rates observed for more than 300 hours.

• 한국세라믹학회지
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• 제32권2호
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• pp.217-226
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• 1995

Alumina powders were dispersed using crosslinkable organic molecules by electrosteric stabilization and then consolidated by crosslinking of organic molecules. The effect of processing variables such as the physicochemical properties of both solvent media and organic molecules, the proportions of mixed organic media, etc. were studied. FT-IR was used todeduce the mechanism of organic molecules adsorption on the alumina particle surfaces. The adsorption characteristics and the electrokinetic behavior of alumina suspensions were correlated with the stability of particle in alumina suspension using rheological measurements. The green body of alumina consolidated by the chemical crosslinking of the adsorbed organic molecules after the alumina suspension had been stabilized was tough enough for green machining and the sintered alumina fabricated by this proposed process also showed a high bending strength and a homogeneous microstructure.

• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.243-251
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• 2023

Developing oxygen evolution reaction (OER) electrocatalysts is essential to accomplish viable CO₂ and water electrolysis. Herein, we report the fabrication and OER performance of Ni-foam (NF)-immobilized Ni₆ nanoclusters (NCs) (Ni₆/NF) prepared by a dip-coating process. The Ni₆/NF electrode exhibited a high current density of 500 mA/cm² for the OER at an overpotential as low as 0.39 V. Ni₆/NF exhibited high durability in an alkaline solution without corrosion. Electrokinetic studies revealed that OER can be easily initiated on Ni6 NC with fast electron-transfer rates. Finally, we demonstrated stable CO₂-to-CO electroreduction using an NC-based zero-gap CO₂ electrolyzer operated at a current density of 100 mA/cm² and a full-cell potential of 2.0 V for 12 h.

• 한국물환경학회지
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• 제22권3호
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• pp.498-503
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• 2006

Adsorption features of $Cd^{2+}$ on waste tire particles have been investigated for the purpose of enhanced wastes recycling along with the development of an economic process for wastewater treatment. The isoelectric point of waste tire particles was found to be ca. pH 7 and the adsorbed amount of $Cd^{2+}$ was increased with pH under experimental conditions. The variation of the adsorption behavior of $Cd^{2+}$ with pH was well explained by the change of the electrokinetic potential of waste tire particles according to the pH. Adsorption of $Cd^{2+}$ was observed to reach its equilibrium within 45 minutes after the adsorption started under experimental conditions and followed the Freundlich model well. Kinetic analysis showed that the adsorption reaction of $Cd^{2+}$ was second order and thermodynamic estimation substantiated the endothermic behavior of $Cd^{2+}$ adsorption. As the amount of adsorbent increased, more adsorption of $Cd^{2+}$ was accomplished and the adsorption capacity of adsorbent was found to be enhanced by its pre-treatment with NaOH. Also, the adsorption of adsorbate was promoted as the ionic strength of wastewater was increased.