• 한국지반환경공학회 논문집
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• 제15권4호
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• pp.37-41
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• 2014

펄스동전기법은 점토성-사질토에서 탈수화 공정을 효율적으로 진행하기 위해 제안되었다. 제안된 동전기법은 점토성-사질토에서 토양 안정성의 증진을 위해 전류 흐름에 따르는 유체의 이동에 의한 탈수화 공정을 진행하는 것이다. 제안된 동전기법의 성능을 확인하기 위해 제작된 샘플은 총 7일간에 점진적으로 압력을 증가시켜 30 psi($2.11kgf/cm^2$)의 최종압력으로 압축과정을 거쳐 완성되었다. 기존의 연속적인 처리와 펄스방식으로 처리하는 공정을 비교하여 각각의 특성을 관찰하였다. 각각의 테스트는 48시간 동안 3 V/cm의 전압 경사 조건으로 연속적인 처리공정과 48시간 동안 총 8시간씩 3회에 걸쳐 전기를 차단하는 펄스방식으로 진행하였다. 그 결과, 펄스방식의 효율이 연속처리방식의 효율과 비슷한 것으로 나타났고 펄스방식이 연속처리방식보다 전력소비가 약 50 % 감소로 그 경제성을 입증하였다.

• Geomechanics and Engineering
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• 제19권1호
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• pp.11-20
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• 2019

The use of electrokinetic dissipation method to study the fluid flow law in micro-pores is of great significance to reservoir rock microfluidics. In this paper, the micro-capillary theory was combined with the coupling model of the seepage field and the current field under the excitation of the harmonic signal, and the coupling theory of the electrokinetic effect under the first-order approximation condition was derived. The dissipation equation of electrokinetic dissipation and viscous resistance dissipation and its solution were established by using Green's function method. The physical and mathematical models for the electrokinetic dissipation of reservoir rocks were constructed. The microscopic mechanism of the electrokinetic dissipation of reservoir rock were theoretically clarified. The influencing factors of the electrokinetic dissipation frequency of the reservoir rock were analyzed quantitatively. The results show that the electrokinetic effect transforms the fluid flow profile in the pores of the reservoir from parabolic to wavy; under low-frequency conditions, the apparent viscosity coefficient is greater that one and is basically unchanged. The apparent viscosity coefficient gradually approaches 1 as the frequency increases further. The viscous resistance dissipation is two orders of magnitude higher than the electrokinetic effect dissipation. When the concentration of the electrolyte exceeds 0.1mol/L, the electrokinetic dissipation can be neglected, while for the electrolyte solution (<$10^{-2}M$) in low concentration, the electrokinetic dissipation is very significant and cannot be ignored.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.210-214
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• 2002

In this study, the coupled effect of electrokinetic and ultrasonic remediation technology was investigated for removing of heavy metal and organic matter at the same time. The laboratory tests were conducted using specially designed and fabricated electrokinetic and ultrasonic devices. The electrokinetic technique was applied to remove mainly the heavy metal and the ultrasonic technique was applied to remove mainly organic substance in contaminated soil. Diesel fuel and Cd were used as a surrogate contaminant for this test. A series of laboratory experiments involving electrokinetic and electrokinetic+ultrasonic flushing test were carried out. An increase in permeability and contaminant removal rate was observed in electrokinetic+ultrasonic flushing test.

• Membrane and Water Treatment
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• 제11권3호
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• pp.189-193
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• 2020

In this study, electrokinetic remediation equipment was used to remove cesium (Cs) from clay soil and waste solution was treated with sorption process. The influence of electrokinetic process on the removal of Cs was evaluated under the condition of applied electric voltage of 15.0-20.0 V. In addition to monitoring the Cs removal, electrical current and temperature of the electrolyte during experiment were investigated. The removal efficiency of Cs from soil by electrokinetic method was more than 90%. After electrokinetic remediation, Cs was selectively separated from soil waste solution using sorbents. Various adsorption agents such as potassium nickel hexacyanoferrate (KNiHCF), Prussian blue, sodium tetraphenylborate (NaTPB), and zeolite were compared and KNiHCF showed the highest Cs removal efficiency. The Cs adsorption on KNiHCF reached equilibrium in 30 min. The maximum adsorption capacity was 120.4 mg/g at 0.1 g/L of adsorbent dosage. These results demonstrated that our proposed process combined electrokinetic remediation of soil and waste solution treatment with metal ferrocyanide can be a promising technique to decontaminate Cs-contaminated fine soil.

• Nuclear Engineering and Technology
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• 제41권8호
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• pp.1079-1086
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• 2009

A great volume of radioactive concrete is generated during the operation and the decommissioning of nuclear facilities. The washing-electrokinetic technology in this study, which combined an electrokinetic method and a washing method, was developed to decontaminate the concrete generated in nuclear facilities. The results of only an electrokinetic decontamination for the concrete showed that cobalt was removed to below 1% from the concrete due to its high pH. Therefore, the washing-electrokinetic technology was applied to lower the pH of the concrete. Namely, when the concrete was washed with 3 M of hydrochloric acid for 4 hours (0.17 day), the $CaCO_3$ in the concrete was decomposed into $CO_2$ and the pH of the concrete was reduced to 3.7, and the cobalt and cesium in the concrete were removed by up to 85.0% and 76.3% respectively. Next, when the washed concrete was decontaminated by the electrokinetic method with 0.01M of acetic acid in the 1L electrokinetic equipment for 14.83 days, the cobalt and the cesium in the concrete were both removed by up to 99.7% and 99.6% respectively. The removal efficiencies of the cobalt and cesium by 0.01M of acetic acid were increased more than those by 0.05M of acetic acid due to the increase of the concrete zeta potential. The total effluent volume generated from the washing-electrokinetic decontamination was 11.55L (7.2ml/g).

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권5호
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• pp.1-7
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• 2010

Electrokinetic technology was applied to remediate Cu, Pb and As-contaminated paddy soil. Removal of metal is highly dependent on the processing fluid during electrokinetic treatment. Tap water, NaOH, $HNO_3$, $Na_2EDTA$, and citric acid were evaluated as the processing fluids to enhance metal removal. Cu and Pb were transported toward cathode, however, it did not removed from soil section, while 56.6% of As was removed at a acidic condition. The strong acidic condition with nitric acid as a processing fluid enhanced the desoprtion of As from soil surface. However, longer operation time is needed to get the higher removal of Cu and Pb, and the acidification of soil after electrokinetic treatment should be solved.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.6-15
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• 2013

The influence of processing fluids and electrode spacing on the electrokinetic process was evaluated to remediate As-, Cu-, Pb-contaminated soil. Single and mixture of sodium citrate, EDTA and NaOH was used to investigate the metal extraction. EDTA for washing reagent showed the highest removal efficiency. Based on the extraction result, the electrode spacing (20, 40, 60 cm) on the electrokinetic process was investigated to remove the multi-metals from soil. The highest removal was observed at the experiment with 60 cm of electrode spacing, however, the correlation between electrode spacing and removal of metals was not clear. The electrode spacing influenced the amount of accumulated electro-osmotic flow. BCR sequential extraction showed that electrokinetic process removed the fractionation of metals bound to Fe-Mn oxyhydroxide.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2007년도 춘계 지질과학기술 공동학술대회
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• pp.37-39
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• 2007

See Full Text

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.306-309
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• 2003

Surfactant-enhanced electrokinetic (EK) remediation is an emerging technology that can effectively remove hydrocarbons from low-permeability soils. In this study, the electrokinetic remediation using Calfax 16L-35 was conducted for the removal of phenanthrene from kaolinite. An anionic surfactant Calfax 16L-35 was used at concentrations of 5, 15, and 30g/L to enhance the solubility of phenanthrene. When the surfactant solution was applied to EK system, low electrical potential gradient was maintained because of its ions. Even when the surfactant concentration was high, the removal efficiency of phenanthrene was low After the operation, most of surfactants were remained in soil and there were few in effluent. This phenomena was observed because the migration of Calfax 16L-35 from cathode to anode was predominant over electroosmotic flow which moved in opposite direction. Therefore, the anionic surfactant Calfax 16L-35 is considered to be improper in surfactant - enhanced electrokinetic remediation.

• 한국지반공학회논문집
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• 제19권3호
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• pp.83-91
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• 2003

본 논문에서는 동전기초음파정화기술을 이용하여 오염지반내의 중금속 및 유기물질을 제거하는 연구를 수행하였는데, 지반내 오염물질의 이동 및 제거에 대한 동전기기술과 초음파기술의 복합효과 분석에 초점을 두었다. 일반적으로 오염지반내에서 동전기기술은 중금속을 제거하는데 탁월하며 초음파기술은 유기물질을 제거하는데 탁월한 것을 보고되어 있는바 이들 두 기술의 장점을 이용한 복합기술을 고안하게 되었다. 특수하게 고안된 실험장비를 이용하여 동전기기술과 초음파기술을 결합한 실내토양세척실험을 실시하였다. 본 실험에서는 단순, 동전기, 초음파, 동전기&초음파의 4조건에 대하여 토양세척실험을 실시하였다. 오염물질로는 중금속으로는 납, 유기물질로는 에틸렌글리콜을 사용하였다. 실험결과 동전기기술과 초음파기술을 도입한 경우 유출량, 투수계수, 오염물질 제거율이 단순기술에 비하여 상대적으로 크게 증가하는 것으로 나타났다. 본 연구를 통하여 동전기초음파정화기술을 현장에 적용할 수 있는 가시적인 결과를 얻게 되었다.