• Title/Summary/Keyword: electro-Osmosis

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Dehydration by Electro-osmosis on Ceramic Body (Electro-osmosis에 의한 Dehydration)

  • Han, Sang-Mok
    • Journal of Industrial Technology
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    • v.4
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    • pp.43-46
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    • 1984
  • In process of water removing safely from plastic clay, an electric field applied to a wet, porous solid such as day usually causes the rapid dehydration. The water-bearing positive ions move to negative electrode under the d. c. electrical stress or field. Therefore application of electro-osmosis to wet clay could include drying thick and large-scale ceramic body quickly and evenly. The d. c. power supply unit to 60 volts is necessary for safe practice. Also wider contact area and shorter distance between electrodes accelerate effectively the removal of water.

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The Effects of Electro-Osmosis and Compression on the Dewatering of Agricultural Wastes (고함수 농산폐기물의 탈수과정에서 전기침투와 압력의 효과)

  • 김영중;윤진하;이운용
    • Journal of Biosystems Engineering
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    • v.21 no.1
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    • pp.52-59
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    • 1996
  • In this study, the combined forces of electro-osmosis and compression were applied to cabbage dewatering and their effects were discussed. Nine treatments of combined forces consisting of three levels of voltage and compression were applied to chopped and macerated chinese cabbage placed in the experimental set-up consisted of cylinder-piston. The results showed that as both voltage and pressure increased the dewatering rates increased and the combined force of voltage and compression was a very effective means in the dewatering of chinese cabbage in which the largest dewatering rate difference, 72%, was found between the combined force of 30V with 68.2kPa and no voltage(0V) with 68.2kPa. However, no significant difference was found between the voltage of 0 and 10volts in 9.75kPa and the pressure of 68.2kP and 126.7kPa in 30volts. The maximum and minimum dewatering rate were 82% in the combined force of 30 volts of 126.7kPa and 8% in 0 volt of 9.75kPa, respectively. Within the experimental trials, it appeared that the best treatment combination would be pressure of 68.2kPa and voltage of 30V producing dewatering rate of 80ft in which the produced liquid contained about 1% solid. Employing this dewatering method as a pretreatment before drying process can contribute in considerable energy saving in agricultural wastes treatment.

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Effect of electrochemical treatment on consolidation of soft clay

  • Li, Xiaobing;Yuan, Guohui;Fu, Hongtao;Wang, Jun;Cai, Yuanqiang
    • Geomechanics and Engineering
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    • v.15 no.4
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    • pp.957-964
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    • 2018
  • In this study, a method of electrochemical consolidation is applied. This method utilizes electro-osmosis, which is an effective ground improvement technique for soft clays, and soil treatment using lime, which is the oldest traditional soil stabilizer. The mechanism of lime treatment for soil involves cation exchange, which leads to the flocculation and agglomeration. Five representative laboratory tests-an electro-osmotic test and four electrochemical tests with various proportions of lime-were performed on dredged marine clay. The objectives of this study are to investigate the effect of electrochemical treatment and to determine the optimum dose for optimal consolidation performance of dredged marine clay. The results show that a better consolidation effect was achieved in terms of current, temperature, and vane shear strength by using electrochemical treatment. The best results were observed for the electrochemical test using 4% lime content.

Mixing in a Microchannel by using Induced-charge Electro-osmosis (마이크로 채널 내 유도-전하 전기삼투에 의한 혼합)

  • Jeon, Young-Hun;Heo, Young-Gun;Jung, Won-Hyuk;Alapati, Suresh;Suh, Yong-Kweon
    • Journal of the Korean Society of Visualization
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    • v.8 no.4
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    • pp.13-18
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    • 2010
  • This paper presents an experimental study on the performance of a micro-mixer using AC electro-osmotic flow. The microchannel is made of PDMS for the side and top walls and glass patterned with ITO for the bottom wall. We first investigated the effect of the applied potential as well as the frequency on the slip velocity. We have found that the slip velocity is roughly proportional to the applied voltage in line with the Helmholtz-Smoluchowski equation and there is an optimum frequency at which the slip velocity becomes maximized. To find the optimum parameters for mixing device we tested our device for various design parameters. It turned out that the best mixing effect is obtained approximately when the electrode angle is $30^{\circ}$, electrode width $200\;{\mu}m$, and the frequency of power supply 700 Hz.

Effect of Electro-Osmosis Method on Marine Clay with Preloading (선행하중이 작용하는 해성점토지반에 전기삼투공법의 효과)

  • Kang, Hongsig;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.2
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    • pp.53-58
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    • 2015
  • The Pre-loading method has been widely used for the soft ground stabilization but long construction times and the transport of large quantities of fill material are required. To shorten the construction periods, the vertical drain method is generally applied simultaneously. But the high costs of the fill materials along with environmental damages remain as the main difficulties to apply this method. Therefore, a complimentary way to reduce both the height of the embankment and the consolidation time is needed. In this study, the electro-osmosis method, which is able to shorten the consolidation time and minimize the damage of the environment, was performed with a model test. The results show that as the voltage increases the consolidation settlements, consolidation drainage and shear strength also increase while the water content decreases.

A Study on Filed Application of Electro-Osmosis Soil Improvement Method with Nano-Coated Plastic Drain Baord (나노 코팅된 PDB를 이용한 동전기 지반개량 공법의 현장 적용성에 관한 연구)

  • Ahn, Sangro;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.10
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    • pp.5-11
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    • 2018
  • The PBD (Plastic Board Drain) method is one of effective ground improvement methods on the soft dredging reclamation ground. This method has outstanding economic efficiency and constructability, and it is widely used for the soft ground improvement. However, the PBD method reduces permeability and drainage capacity of the ground due to the long construction period. Therefore, the nano coated Plastic drain board (PDB) was developed to solve problems. It is the non-metallic electrode and improves the weakness of the PBD method by using electric force of the electro-osmosis method. Various researches have been conducted to apply the nano coated PDB, but these researches were limited to model tests in laboratory. In this study, model and field tests were conducted to assess field applicability of the nano coated PDB. The result showed that the nano coated PDB had the better effect on the ground improvement compared to the normal PDB.

Comparison of Nitrate and Fluoride Removals between Reverse-Osmosis, Nano-Flitration, Electro-Adsorption, Elecero-Coagulation in Small Water Treatment Plants (소규모 수도시설의 역삼투(RO), 나노여과(NF), 전기흡착(EA), 전기응집(EC) 공정의 질산성 질소 및 불소 이온 제거 성능 비교)

  • Han, Song-Hee;Chang, In-Soung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.2027-2036
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    • 2013
  • Comparison of removal performance between reverse osmosis(RO), nanofiltration(NF), electrocoagulation(EC) and electroadsorption(EA) for removal of nitrate and fluoride often exceeded the limits of water quality in small water treatment plants. Removals of nitrate and fluoride were 72-92% and 74-85% in RO, 5-15% and 1% in NF, 99% and 44% in EA equipped with MWCNT coated electrodes, 82% and 77% in EA equipped with Cu-MWCNT electrodes, and 11-46% and 69-99% in EC. Consequently, high removals of both ions were anticipated in RO. Effective removal of both ions are possible for EC, but great production of sludge is a big burden. EA equipped with the MWCNT electrodes showed a great fluctuation in removal efficiency, and electrode stability should be upgraded.